CA2114224A1 - Use of collagen as a solid binding substrate for a specific sensor - Google Patents
Use of collagen as a solid binding substrate for a specific sensorInfo
- Publication number
- CA2114224A1 CA2114224A1 CA002114224A CA2114224A CA2114224A1 CA 2114224 A1 CA2114224 A1 CA 2114224A1 CA 002114224 A CA002114224 A CA 002114224A CA 2114224 A CA2114224 A CA 2114224A CA 2114224 A1 CA2114224 A1 CA 2114224A1
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- Prior art keywords
- atelocollagen
- collagen
- biological
- polyholoside
- use according
- Prior art date
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N33/00—Investigating or analysing materials by specific methods not covered by groups G01N1/00 - G01N31/00
- G01N33/48—Biological material, e.g. blood, urine; Haemocytometers
- G01N33/50—Chemical analysis of biological material, e.g. blood, urine; Testing involving biospecific ligand binding methods; Immunological testing
- G01N33/53—Immunoassay; Biospecific binding assay; Materials therefor
- G01N33/543—Immunoassay; Biospecific binding assay; Materials therefor with an insoluble carrier for immobilising immunochemicals
- G01N33/544—Immunoassay; Biospecific binding assay; Materials therefor with an insoluble carrier for immobilising immunochemicals the carrier being organic
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N33/00—Investigating or analysing materials by specific methods not covered by groups G01N1/00 - G01N31/00
- G01N33/48—Biological material, e.g. blood, urine; Haemocytometers
- G01N33/50—Chemical analysis of biological material, e.g. blood, urine; Testing involving biospecific ligand binding methods; Immunological testing
- G01N33/53—Immunoassay; Biospecific binding assay; Materials therefor
- G01N33/543—Immunoassay; Biospecific binding assay; Materials therefor with an insoluble carrier for immobilising immunochemicals
- G01N33/54313—Immunoassay; Biospecific binding assay; Materials therefor with an insoluble carrier for immobilising immunochemicals the carrier being characterised by its particulate form
- G01N33/5432—Liposomes or microcapsules
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N33/00—Investigating or analysing materials by specific methods not covered by groups G01N1/00 - G01N31/00
- G01N33/48—Biological material, e.g. blood, urine; Haemocytometers
- G01N33/50—Chemical analysis of biological material, e.g. blood, urine; Testing involving biospecific ligand binding methods; Immunological testing
- G01N33/53—Immunoassay; Biospecific binding assay; Materials therefor
- G01N33/543—Immunoassay; Biospecific binding assay; Materials therefor with an insoluble carrier for immobilising immunochemicals
- G01N33/54313—Immunoassay; Biospecific binding assay; Materials therefor with an insoluble carrier for immobilising immunochemicals the carrier being characterised by its particulate form
- G01N33/54326—Magnetic particles
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N33/00—Investigating or analysing materials by specific methods not covered by groups G01N1/00 - G01N31/00
- G01N33/48—Biological material, e.g. blood, urine; Haemocytometers
- G01N33/50—Chemical analysis of biological material, e.g. blood, urine; Testing involving biospecific ligand binding methods; Immunological testing
- G01N33/53—Immunoassay; Biospecific binding assay; Materials therefor
- G01N33/543—Immunoassay; Biospecific binding assay; Materials therefor with an insoluble carrier for immobilising immunochemicals
- G01N33/544—Immunoassay; Biospecific binding assay; Materials therefor with an insoluble carrier for immobilising immunochemicals the carrier being organic
- G01N33/548—Carbohydrates, e.g. dextran
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- Health & Medical Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- Immunology (AREA)
- Engineering & Computer Science (AREA)
- Molecular Biology (AREA)
- Biomedical Technology (AREA)
- Chemical & Material Sciences (AREA)
- Hematology (AREA)
- Urology & Nephrology (AREA)
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Cell Biology (AREA)
- Food Science & Technology (AREA)
- Medicinal Chemistry (AREA)
- Biotechnology (AREA)
- Analytical Chemistry (AREA)
- Biochemistry (AREA)
- General Health & Medical Sciences (AREA)
- Microbiology (AREA)
- Pathology (AREA)
- Measuring Or Testing Involving Enzymes Or Micro-Organisms (AREA)
- Macromolecular Compounds Obtained By Forming Nitrogen-Containing Linkages In General (AREA)
- Medicines Containing Material From Animals Or Micro-Organisms (AREA)
- Treatment Of Liquids With Adsorbents In General (AREA)
- Investigating Or Analysing Biological Materials (AREA)
- Peptides Or Proteins (AREA)
- Pharmaceuticals Containing Other Organic And Inorganic Compounds (AREA)
- Medicinal Preparation (AREA)
- Heterocyclic Carbon Compounds Containing A Hetero Ring Having Oxygen Or Sulfur (AREA)
Abstract
ABSTRACT OF THE DISCLOSURE
The invention relates to the use of collagen as solid binding substrate for a sensor called ligand or refining agent, capable of reacting specifically with an element to be detected in a biological medium, to form a specific complex.
Preferably, the solid substrate comprises atelocollagen or a mixture of atelocollagen and of polyholoside.
The invention thus makes it possible to provide a biological reactant of high specificity and of which the constituents are of natural origin. It can be used easily and quickly.
The invention relates to the use of collagen as solid binding substrate for a sensor called ligand or refining agent, capable of reacting specifically with an element to be detected in a biological medium, to form a specific complex.
Preferably, the solid substrate comprises atelocollagen or a mixture of atelocollagen and of polyholoside.
The invention thus makes it possible to provide a biological reactant of high specificity and of which the constituents are of natural origin. It can be used easily and quickly.
Description
21~22~
~ 1 Use of collagen as so id binding substrate for a sensor capable of reacting specifically with an element to be detected in a biological medium~ reactant andimplementation method.
S The present invention essentially relates to the use of collagen as solid binding substrate for a sensor capable of reacting specifically with an element to be detected in a biological medium, reactant and implementation method.
It is already known from US document YAPEV3M US-A-4 16~ 804 to produce magnetically responsive composite microparticles comprising a magnetically responsive material and a porous solid water-insoluble matrix selected from proteinaceous materials, polysaccharides and mixtures thereof.
The magnetically responsive material is dispersed throughout the permeable solid water-insoluble matrix (see the abstract and the claims in columns 11 and 12).
Said document also provides the use of said solid porous microparticles as matrix for inclusion of a water-insoluble enzyme (column i, line 66 to column 2, line 2) or of a specific receptor such as a protein or an antibody (see column 2, line 63 to column 3, line 26).
The Applicant has already described in document FR-B1-2 642 329 the use of solutions of atelocollagen and of glycosaminoglycans for the production of microcapsules as well as cosmetic or pharmaceutical or food compositions containing them.
The present inventors have now discovered that collagen, and preferably atelocollagen, and better still a mixture of atelocollagen and polyholosides, constitutes a remarkable solid binding substrate for a sensor capable of reacting specifically with an element to be detected in a biological medium in order to forrn a specific complex which can then be detected by any detection means.
It is a main object of the present invention to solve the new technical problem consisting in providing a solid substrate exhibiting on its external surface a large number of reacting functions or groups, in order to allow the covalent bond of a specific sensor, preferably a specific sensor of an element to be detected in a biological medium particularly for purposes of analysis and/or qualitative or quantitative assay.
Another main object of the present invention is to solve the new technical problem consisting in providing a solid substrate for binding on its .. . . . - : .
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~ 1 Use of collagen as so id binding substrate for a sensor capable of reacting specifically with an element to be detected in a biological medium~ reactant andimplementation method.
S The present invention essentially relates to the use of collagen as solid binding substrate for a sensor capable of reacting specifically with an element to be detected in a biological medium, reactant and implementation method.
It is already known from US document YAPEV3M US-A-4 16~ 804 to produce magnetically responsive composite microparticles comprising a magnetically responsive material and a porous solid water-insoluble matrix selected from proteinaceous materials, polysaccharides and mixtures thereof.
The magnetically responsive material is dispersed throughout the permeable solid water-insoluble matrix (see the abstract and the claims in columns 11 and 12).
Said document also provides the use of said solid porous microparticles as matrix for inclusion of a water-insoluble enzyme (column i, line 66 to column 2, line 2) or of a specific receptor such as a protein or an antibody (see column 2, line 63 to column 3, line 26).
The Applicant has already described in document FR-B1-2 642 329 the use of solutions of atelocollagen and of glycosaminoglycans for the production of microcapsules as well as cosmetic or pharmaceutical or food compositions containing them.
The present inventors have now discovered that collagen, and preferably atelocollagen, and better still a mixture of atelocollagen and polyholosides, constitutes a remarkable solid binding substrate for a sensor capable of reacting specifically with an element to be detected in a biological medium in order to forrn a specific complex which can then be detected by any detection means.
It is a main object of the present invention to solve the new technical problem consisting in providing a solid substrate exhibiting on its external surface a large number of reacting functions or groups, in order to allow the covalent bond of a specific sensor, preferably a specific sensor of an element to be detected in a biological medium particularly for purposes of analysis and/or qualitative or quantitative assay.
Another main object of the present invention is to solve the new technical problem consisting in providing a solid substrate for binding on its .. . . . - : .
.. . , . ~ . . :
:
.
, . . .
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surface a specific sensor exhibiting very good mechanical properties allowing ready dispersion into various mediums, notably due to strong stirring without any substantial deterioration of its initial abilities or properties.
The present invention aims further at solving the new technical problem consisting in providing a solid binding substrate for a specific element to be detected in a biological medium, which is capable of allowing rapid mixing with the biological medium as well as ready separation from said biological medium, with a view to gaining substantial time in medical analyses for medical diagnosis purposes. The invention has solved said technical problems for the first time, in a simultaneous, simple, easy, reliable and inexpensive manner, usable on an industrial and medical scale.
The invention makes it advantageously possible, in a biological application, to provide sensitive and reproducible assays of substance present in biological fluids. Advantageously also, the invention finds an application in the detection of a human rotavirus and in assaying of HCG in a biological fluid such as serum.
Thus, in a first aspect, the present invention relates to the use of collagen, preferably atelocollagen, and better still a rnixture of atelocollagen and of a polyholoside, as solid binding substrate for a sensor, known as ligand or refining agent, capable of specifically reacting with an element to be detected in a biological medium to form a specific complex which can thereafter be detected byany detection means.
According to an advantageous characteristic of this use, the collagen is used in the form of particles, spheres or capsules, preferably of a diameter ranging between about 5 and 500 ,um (micrometers). Capsules and in particular microcapsules are preferred.
According to an advantageous characteristic of the invention, the collagen comprises atelocollagen, preferably in combination with a polyholoside,such as a glycosaminoglycan, dextran or chitosan.
Said solid substrate, when prepared from native collagen, can be produced in particle form by coagulation of droplets.
In the case of atelocollagen, the same procedure can be used.
In the case of a mixture of atelocollagen with a polyholoside, the solid particles are preferably obtained by interface crosslinking as described in Applicant's previous patent FR-B1-2 643 329.
?~ 2 ~ ~
In this case, the relative proportion of polyholoside with respect to atelocollagen advantageously varies between 15 and 50% by weight.
According to another advantageous characteristic of the invention, the particles of collagen contain a magnetic oxide, preferably a magnetic iron oxide.
5Advantageously, the magnetic oxide concentration is comprised between 0.1 and 10 % by weight with respect to the total weight of particles.
According to another particular characteristic of the invention, said sensor is covalently bonded by a chemical agent on the particles of collagen forming solid binding substrate.
10The solid substrate according to the invention has the advantage of presenting superficial chemical fimctions such as the amino (-NH2), carboxylic -(C02H) or alcoholic (-OH) functions, which make it possible to effect the bonding of the sensor forrning ligand or refining agent.
Preferably, in the case of amino functions (-NH2), the chemical 15bonding agent used between the sensor and the solid substrate, will be a reactant of NHS type (N-hydroxysuccinimide), one of which can be reacted with the amino group of the solid substrate and the other with the sensor forming ligand or refining agent. This bonding is preferably effected in two stages, the first stage consisting in bonding the reactant on the surface of the solid particles of the substrate, then, 20having eliminated the excess of chemical bonding reactant, in effecting the bonding of the sensor forming ligand or refining agent with the solid particles of the substrate obtained after the aforesaid first stage.
The chemical bonding agents are said to be homobifunctional if the second reacting group is also of NHS type, and heterobifunctional if the latter is 25different. One example of a different second reacting group is a maleimide group able to bind a molecule by a thiol function (-SH).
In the case of carboxylic functions, the chemical bonding reactants preferably use water-soluble agents of carbodiimide type. Thereagain, they are used according to a method in two stages. Carbodiimides are heterobifunctional 30agents giving a bond of a carboxylic (-COOH) and an amino function (-NH2).
In the case of alcoholic functions, the technique preferably used comprises oxidizing the alcohol function into an aldehyde (CHO) by a smooth oxidizing agent, such as sodium periodate (NaI04). The aldehyde can then be reacted with an amino function (-NH2) by forming a Schiff's base. Hereagain, this 3Sbonding is effected according to a method in two stages, the first stage consisting in oxidizing the alcohol function into aldehyde, the second stage consisting in ... :. . : . ;- ., j . .
- . , :~ :, .
: :
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effecting the bonding proper of the agent forming ligand or refining agent with the solid particles of the substrate obtained at the end of the first stage.
It is worth noting that, by using as solid substrate, collagen, atelocollagen, or an atelocollagen-polyholoside mixture, what is obtained is thepresence, in large quantity, of various superficial functions on the particles of the solid substrate, which makes it easy to effect a bonding of different molecular populations on the same surface, such as for example an antibody and an enzyme.
Two methods may be used to this effect, i.e.
- the mixing of different molecular populations during the bonding phase, which will induce the binding on the surface of the particles of the solid support of a variable part of said populations as a function of the particular reactivity of each population and of their respective concentration.
The result will then be a binding in a predetermined quantity of each population, and this in a reproducible manner, if the reaction conditions are reproduced.
On the other hand, the successive activation of the different functions available on the surface of the solid particles, followed by sequenced bonding of the different molecular populations, thereby making it possible to obtain a solid substrate with multiple specificity.
It will be further noted that according to the invention, the solid substrate is produced from natural substances extracted from animal tissues. This is the case with collagen and atelocollagen, which are long chain proteins extracted from the dermic tissue, as well as with polyholoside, particularly a glycosaminoglycan.
Thus the use according to the invention, of collagen, preferably atelocollagen and better still of an atelocollagen-polyholoside mixture, by binding a sensor forming ligand or refining agent, produces a reactant for the qualitative detection and quantitative measurement of any element whatsoever from a medium of biological origin. By element is meant in the present description and claims, any species of antibodies or antigens, in soluble or particulate form, as well as all the molecular species liable to create specific complexes for which the affinity constant is sufficiently strong to shift the reaction towards the forrnation of the complex.
Said reactant can be used in the conventional way with methods for the qualitative detection and quantitative measurement of an element in a medium of biological origin, in medical analyses for medical diagnosis purposes. Processing is :` s easy and leads to a considerable gain of time due to a rapid mixing up with the biological medium and to a ready separation of the solid particles from said biological medium.
Said reactant enables the implementation of conventional methods 5 known as "immuno-assays" in heterogeneous phase.
The reactant according to the invention enables the detection of elements present in infinitesimal quantity in a complex medium of biological origin due to the ability for the sensor forming ligand or refining agent, which is fixed on the solid phase, to extract and separate the element to be detected.
The medium of biological origin is normally a liquid phase constituted by a liquid of biological origin such as blood, urine, cephalorhachidian liquid, etc.;
or an extract of tissue requiring the use of extraction means of a physical nature such as heat, radiation, etc.; or of a chemical nature such as enzyme, detergent, acid, base, etc. ~ -The sensor forming binding or refining agent, which is fixed on the solid phase or solid substrate according to the invention is specific to the element to be detected and such sensors are wellknown to the man skilled in the art. Such sensors can, in adequate physico-chemical conditions, give rise to the formation of stable complexes notably by immuno-type reactions, which complexes are bonded 20 on the surface of the solid phase and can thus be isolated from the other molecular populations which are present, by any type of method ending into the separation of the solid phase containing the complex bonded thereto.
The presence of the complex can thereafter be revealed by measuring the consumption using for example a technique of competition, or by measuring 25 the proportionally bonded quantity of a labeled tracer which will give a specific signal measurable by a chemical or physical method such as isotopic count, spectrophotometry, luminometry, amperometry, etc. All said techniques are wellknown to the man skilled in the art.
In a second aspect, the invention thus covers as new products, a 30 biological reactant characterized in that it comprises, as a solid substrate or phase, particles of collagen, preferably of atelocollagen, and better still, of a mixture of atelocollagen and polyholoside.
Different variants of embodiment of said reactant result from the foregoing description given in relation to the first aspect of the invention, and will 35 also result from the following description given with reference to various non-restrictive examples of the invention.
r' 211~2'~
In a third aspect, the present invention also covers a method for the detection in a biological medium, of an element to be detected.
According to an advantageous embodiment, the invention relates to a detection method characterized in that the biological reactant used is a biological reactant whose sensor is a human anti-rotavirus antibody, and in that the method is a method for detecting the human rotavirus.
According to another particular embodiment, the invention relates to a detection method characterized in that the biological reactant used is a biological reactant whose sensor is an anti-HCG antibody, and in that the method is a method for assaying the HCG in the serum.
Variants of embodiment of said method are also obvious from the foregoing description, as well as from the following description given with reference to the examples given hereinafter solely by way of illustration.
The polyholosides used are, in particular, glycosaminoglycans which are structural glycosaminoglycans selected from the group consisting of chondroitine-4-sulfate, chondroitine-6-sulfate, dermatane-sulfate, heparane-sulfate and keratane-sulfate, as well as heparin and its derivatives, particularly the derivatives of low molecular weight whose molecular weight can vary between 2,000 and 10,000. Chitosan and dextrane can also be used as polyholosides.
The polyholoside is used in particular in the forrn of aqueous solution at 0.5 to 4% and preferably 0.5 to 2%, and preferably still about 1%, by weight,with respect to the polyholoside solution.
The collagen, or preferably the atelocollagen, is preferably used in aqueous solution with a collagen or atelocollagen concentration comprised between 0.5 and 2% by weight. This solution of collagen or atelocollagen can be obtained by dissolving collagen or atelocollagen fibers in a slightly acid aqueous solution. Said slightly acid aqueous solution can be preferably an aqueous acid solution of 0.1 M acetic acid. The atelocollagen can be obtained by enzymatic digestion of collagen wellknown to the man skilled in the art.
To prepare the mixture of collagen, and preferably atelocollagen, polyholoside, the polyholoside solution is advantageously introduced into the collagen and preferably atelocollagen solution. Then, the solid particles, in particular the microcapsules, are prepared according to a preparation method by interfacial crosslinking such as described in document FR-B1-2 642 329.
According to said methods, after homogeneously mixing the solution of collagen, preferably atelocollagen, with the polyholoside solution, an oily phase 2 ~ ~22~ `
.
containing a crosslinking agent in dispersed phase form is dispersed into the continuous phase formed by the solution of a mixture of collagen, preferably atelocollagen and polyholoside, under stirring for the time required to obtain asuitable degree of interfacial c}osslinking, thus permitting the production of 5 microcapsules whose wall is a mixed wall of crosslinked collagen, preferably atelocollagen, and crosslinked polyholoside. ` `
The microcapsules are separated in an appropriate way by a natural decantation after one or more washings if necessary.
It is also possible to proceed by extrusion of a laminar flow through an 10 extrusion nozzle, the laminar flow being subjected to vibrations so as to form individual droplets which thereafter drop into a crosslinking bath cointaining the crosslinking agent.
Acid chloride, acid anhydride, or a dibasic or polybasic carboxylic acid are advantageously used as crosslinking agent. A preferred crosslinking agent is15 selected from the group consisting of terephtaloyl chloride, a phtaloyl chloride, a sebacoyl chloride, a succinyl chloride, a chloride of a tricarboxylic acid such as citric acid or an acid anhydride such as succinic anhydride.
A hydrophobic liquid is used as solvent of the crosslinking agent, in which liquid collagen, preferably atelocollagen and/or polyholoside, are insoluble.
20 Cyclohexane or chloroforrn, are still preferably used.
Due to the use of an interfacial crosslinking method, it is thus possible to prepare microcapsules which can encapsulate any kind of active ingredient. Inparticular, it is advantageous to encapsulate in the microcapsules a magnetic particle such as an iron oxide, this enabling easy separation of the solid substrate 25 from the solutions to be analyzed and constituting an important technical advantage of the invention. Indeed, a separation time less than S secs. is obtained over a 1 cm distance in the presence of a simple permanent magnet. This is due to their relatively important mass linked to a density close to 1 which requires only a small charge of magnetic oxide about 1% by weight, to reach that result. Then, 30 magnetic stirring becomes possible. The solid substrate according to the invention has a relatively high volume which makes it unresponsive to the aggregation forces, whether of hydrophobic or ionic nature. This further enables rapid separation during production by low speed centrifuging, such as for example around 800 g for 2 mins., and resuspension in non-aggregated form by simple 35 stirring.
2 2 ~
The particlcs of the solid substrate according to the invention can be obtained in interrnediate size for example of about 50 ~an, due to the production method used, particularly interfacial crosslinking, thus enabling sufficient reacting surfaces to be obtained during an immunoassay (for example 625 mm2 for 50,ul of 5 particles of solid substrate in suspension at 10% by weight). Said external surface is permanently in contact with the reaction liquid. Therefore, it is an extremely efficient surface.
The particles of the solid substrate according to the invention are hydrophilic by nature, because of its chemical constitution. It is known that the 10 polyholosides are chain forrnations of sugars havin~ in their structure numerous hydrophilic functions. Moreover, it is also possible to incorpoIate chito3an as polyholoside, thus enabling solid particles to be obtained, which particles have a low ionic charge.
Moreover, the chemical covalent bonding according to the invention 15 also enables graftings to be obtained, whic i1 graftings are s~rongly bonded, stable, and fixed in a selected direction, for example and advantageously for boncling peptides, this af~ording a maximum efficiency of reaction.
Other objects, characteristics and advantages of the invention will be more clearly understood from the following explanatory description given with 20 reference to several examples of embodiment which are given solely for illustration purposes and therefore which cannot possibly limit the invention in any way.
In the examples, all the percentages are given by weight, except othelwise stated.
25 Example 1 according to the invention Bonding of polyclonal antibody with solid magnetic particles by EDC
(1-ethyl-3-(3-dimethylaminopropyl)carbodiimide): application to the detection of human rotavirus in the stools.
1. Preparation of the solid particles (in microc~psule form) 30 Principle:
Solid particles of average size, about 50 ,um, were prepared and crosslinked after emulsion in an aqueous solution of atelocollagen and chitosan in an oily phase. Said prcparation was made according to the method described in Example 1 of FR-B1-2 642 329 (89-01221). The incorporaIi~-n of magnetic iron 35 oxide (FE304) makes it possible to obtain a solid phase separable by action of a magnetic field.
2 ~ 2 4 ~ -g Mode Operandi To a 1.6% solution of atelocollagen are added 10% of a 3% solution of KITAN in lactic acid. The atelocollagen is prepared according to the method described in French Patent No. 89 01221.
S The KITAN~ is supplied by the company ABER TECE~NOLOGIES, Prat Menau 29880 Plouguemeau France. The KITAN is a chitosan of molecular mass 1,200,000 daltons, having a desacetylation rate of 2.4%.
To the atelocollagen-Kitan mixture is added a 5% concentration of sodium carbonate. The pH is then adjusted to 8.0 with HCI N/10. In this preparation, 1% iron oxide Fe304 is introduced. 100 g of the resulting mixture are emulsified in 3900 ml of DRAGOXAT(~' sold by the German company DRAGOCO and containing 5% of SP~N 85~9 sold by ICI COMPANY. The emulsion is obtained by quick stirring with an Ultra Turax R stirring system, turning at 15,000 rpm for 2 hours.
400 Ml of DRAGOXAT~) containing the crosslinking agent, i.e. 2.5%
terephtalic acid chloride are added to the emulsion kept under stirring for 30 mins.
at 15,000 rpm.
The crosslinking agent is eliminated by centrifuging at 1,500 g for 10 mins. and by rejection of the resulting supernatant.
Three successive washings are carried out with 400 ml of DRAGOXAT~', the collagenic capsules being recovered by centrifuging in the same conditions as before. Six washings, using each time 600 ml of ethanol are carried out in order to remove the residual DRAGOXAT. Two washings with 60 ml of a soda solution at pEI 9 and three washings with de-ionized water enable the removal of the aggregates of capsules. A deposit of solid particles is thus obtained after centrifuging at 1,500 g for 10 mins.
Said deposit is then dispersed in an equal volume of de-ionized water containing 0.01 % of sodium mercurothiolate. Such dispersion of solid particles will be that used in the detections and assays described he}eunder.
2. Preparation of a specific reactant for an immunoassay Anti-rotavirus antibodies of gamma G type are used, which antibodies are purified from a hyperimmunized rabbit serum by a suspension of bovine rotavirus. The presence of anti-antigen antibodies of the virus group enables the detection of the human virus. The purity of the gamma globulins is checked by electrophoresis. The protein assay in weight/volume is effected by Lowry's technique.
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Tl.e bol~ding of the antibodies on the solid magnetic particles obtained in stage 1 hereinabove is performed by using the carboxylic functions (-COOH) ofcollagen.
The solid particles are washed beforehand in a buffer of pH close to 5 neutrality (comprised between 7 and 7.5) of low ionic strength and free from amine (such as for example: 10 mM Hepes buffer).
The solid particles are activated by a soluble carbodiimide (for example EDC (1-ethyl-3-(3-dimethylaminopropyl)carbodiimide) at a concentration varying between S and 100 mM (for example 20 mM) diluted in the 10 10 mM Hepes buffer.
The proportion will be 1 volume of solid magnetic particles for 1 -volume of EDC. The activation will take place under moderate stirring (for example on a rotary agitator) of the suspension for 1 hour between 20 and 25-C.
The excess of EDC is thereafter eliminated by washing of the solid particles in a 10 15 mM Hepes buffer (4 successive washings by addition of 9 volumes of buffer) and recovery of the solid particles by centrifuging or by magnetism.
The bonding of the garnma G of the rabbit (dialyzed beforehand in a 0.15 M Na solution) is performed by adding to the last centrifugation pellet 1 volume of 0.1 M carbonate-bicarbonate buffer and 1 mg of gamma G per ml of 20 pellet. The bonding is performed at room temperature on a rotary agitator for one hour. - -~
Blocking of the residual functions is performed by adding 10% of the total volume of a 1 M ethanolamine solution, of pH 9.0, and by stirring for one hour at between 20 and 25-C.
A se~uence of 4 final washings with a 50 mM Tris buffer enables the elimination of the antibodies which have not been reacted and the 10%
resuspension in said buffer makes it possible to obtain the final suspension of the specific reactant which is sought.
surface a specific sensor exhibiting very good mechanical properties allowing ready dispersion into various mediums, notably due to strong stirring without any substantial deterioration of its initial abilities or properties.
The present invention aims further at solving the new technical problem consisting in providing a solid binding substrate for a specific element to be detected in a biological medium, which is capable of allowing rapid mixing with the biological medium as well as ready separation from said biological medium, with a view to gaining substantial time in medical analyses for medical diagnosis purposes. The invention has solved said technical problems for the first time, in a simultaneous, simple, easy, reliable and inexpensive manner, usable on an industrial and medical scale.
The invention makes it advantageously possible, in a biological application, to provide sensitive and reproducible assays of substance present in biological fluids. Advantageously also, the invention finds an application in the detection of a human rotavirus and in assaying of HCG in a biological fluid such as serum.
Thus, in a first aspect, the present invention relates to the use of collagen, preferably atelocollagen, and better still a rnixture of atelocollagen and of a polyholoside, as solid binding substrate for a sensor, known as ligand or refining agent, capable of specifically reacting with an element to be detected in a biological medium to form a specific complex which can thereafter be detected byany detection means.
According to an advantageous characteristic of this use, the collagen is used in the form of particles, spheres or capsules, preferably of a diameter ranging between about 5 and 500 ,um (micrometers). Capsules and in particular microcapsules are preferred.
According to an advantageous characteristic of the invention, the collagen comprises atelocollagen, preferably in combination with a polyholoside,such as a glycosaminoglycan, dextran or chitosan.
Said solid substrate, when prepared from native collagen, can be produced in particle form by coagulation of droplets.
In the case of atelocollagen, the same procedure can be used.
In the case of a mixture of atelocollagen with a polyholoside, the solid particles are preferably obtained by interface crosslinking as described in Applicant's previous patent FR-B1-2 643 329.
?~ 2 ~ ~
In this case, the relative proportion of polyholoside with respect to atelocollagen advantageously varies between 15 and 50% by weight.
According to another advantageous characteristic of the invention, the particles of collagen contain a magnetic oxide, preferably a magnetic iron oxide.
5Advantageously, the magnetic oxide concentration is comprised between 0.1 and 10 % by weight with respect to the total weight of particles.
According to another particular characteristic of the invention, said sensor is covalently bonded by a chemical agent on the particles of collagen forming solid binding substrate.
10The solid substrate according to the invention has the advantage of presenting superficial chemical fimctions such as the amino (-NH2), carboxylic -(C02H) or alcoholic (-OH) functions, which make it possible to effect the bonding of the sensor forrning ligand or refining agent.
Preferably, in the case of amino functions (-NH2), the chemical 15bonding agent used between the sensor and the solid substrate, will be a reactant of NHS type (N-hydroxysuccinimide), one of which can be reacted with the amino group of the solid substrate and the other with the sensor forming ligand or refining agent. This bonding is preferably effected in two stages, the first stage consisting in bonding the reactant on the surface of the solid particles of the substrate, then, 20having eliminated the excess of chemical bonding reactant, in effecting the bonding of the sensor forming ligand or refining agent with the solid particles of the substrate obtained after the aforesaid first stage.
The chemical bonding agents are said to be homobifunctional if the second reacting group is also of NHS type, and heterobifunctional if the latter is 25different. One example of a different second reacting group is a maleimide group able to bind a molecule by a thiol function (-SH).
In the case of carboxylic functions, the chemical bonding reactants preferably use water-soluble agents of carbodiimide type. Thereagain, they are used according to a method in two stages. Carbodiimides are heterobifunctional 30agents giving a bond of a carboxylic (-COOH) and an amino function (-NH2).
In the case of alcoholic functions, the technique preferably used comprises oxidizing the alcohol function into an aldehyde (CHO) by a smooth oxidizing agent, such as sodium periodate (NaI04). The aldehyde can then be reacted with an amino function (-NH2) by forming a Schiff's base. Hereagain, this 3Sbonding is effected according to a method in two stages, the first stage consisting in oxidizing the alcohol function into aldehyde, the second stage consisting in ... :. . : . ;- ., j . .
- . , :~ :, .
: :
21~22~ `
effecting the bonding proper of the agent forming ligand or refining agent with the solid particles of the substrate obtained at the end of the first stage.
It is worth noting that, by using as solid substrate, collagen, atelocollagen, or an atelocollagen-polyholoside mixture, what is obtained is thepresence, in large quantity, of various superficial functions on the particles of the solid substrate, which makes it easy to effect a bonding of different molecular populations on the same surface, such as for example an antibody and an enzyme.
Two methods may be used to this effect, i.e.
- the mixing of different molecular populations during the bonding phase, which will induce the binding on the surface of the particles of the solid support of a variable part of said populations as a function of the particular reactivity of each population and of their respective concentration.
The result will then be a binding in a predetermined quantity of each population, and this in a reproducible manner, if the reaction conditions are reproduced.
On the other hand, the successive activation of the different functions available on the surface of the solid particles, followed by sequenced bonding of the different molecular populations, thereby making it possible to obtain a solid substrate with multiple specificity.
It will be further noted that according to the invention, the solid substrate is produced from natural substances extracted from animal tissues. This is the case with collagen and atelocollagen, which are long chain proteins extracted from the dermic tissue, as well as with polyholoside, particularly a glycosaminoglycan.
Thus the use according to the invention, of collagen, preferably atelocollagen and better still of an atelocollagen-polyholoside mixture, by binding a sensor forming ligand or refining agent, produces a reactant for the qualitative detection and quantitative measurement of any element whatsoever from a medium of biological origin. By element is meant in the present description and claims, any species of antibodies or antigens, in soluble or particulate form, as well as all the molecular species liable to create specific complexes for which the affinity constant is sufficiently strong to shift the reaction towards the forrnation of the complex.
Said reactant can be used in the conventional way with methods for the qualitative detection and quantitative measurement of an element in a medium of biological origin, in medical analyses for medical diagnosis purposes. Processing is :` s easy and leads to a considerable gain of time due to a rapid mixing up with the biological medium and to a ready separation of the solid particles from said biological medium.
Said reactant enables the implementation of conventional methods 5 known as "immuno-assays" in heterogeneous phase.
The reactant according to the invention enables the detection of elements present in infinitesimal quantity in a complex medium of biological origin due to the ability for the sensor forming ligand or refining agent, which is fixed on the solid phase, to extract and separate the element to be detected.
The medium of biological origin is normally a liquid phase constituted by a liquid of biological origin such as blood, urine, cephalorhachidian liquid, etc.;
or an extract of tissue requiring the use of extraction means of a physical nature such as heat, radiation, etc.; or of a chemical nature such as enzyme, detergent, acid, base, etc. ~ -The sensor forming binding or refining agent, which is fixed on the solid phase or solid substrate according to the invention is specific to the element to be detected and such sensors are wellknown to the man skilled in the art. Such sensors can, in adequate physico-chemical conditions, give rise to the formation of stable complexes notably by immuno-type reactions, which complexes are bonded 20 on the surface of the solid phase and can thus be isolated from the other molecular populations which are present, by any type of method ending into the separation of the solid phase containing the complex bonded thereto.
The presence of the complex can thereafter be revealed by measuring the consumption using for example a technique of competition, or by measuring 25 the proportionally bonded quantity of a labeled tracer which will give a specific signal measurable by a chemical or physical method such as isotopic count, spectrophotometry, luminometry, amperometry, etc. All said techniques are wellknown to the man skilled in the art.
In a second aspect, the invention thus covers as new products, a 30 biological reactant characterized in that it comprises, as a solid substrate or phase, particles of collagen, preferably of atelocollagen, and better still, of a mixture of atelocollagen and polyholoside.
Different variants of embodiment of said reactant result from the foregoing description given in relation to the first aspect of the invention, and will 35 also result from the following description given with reference to various non-restrictive examples of the invention.
r' 211~2'~
In a third aspect, the present invention also covers a method for the detection in a biological medium, of an element to be detected.
According to an advantageous embodiment, the invention relates to a detection method characterized in that the biological reactant used is a biological reactant whose sensor is a human anti-rotavirus antibody, and in that the method is a method for detecting the human rotavirus.
According to another particular embodiment, the invention relates to a detection method characterized in that the biological reactant used is a biological reactant whose sensor is an anti-HCG antibody, and in that the method is a method for assaying the HCG in the serum.
Variants of embodiment of said method are also obvious from the foregoing description, as well as from the following description given with reference to the examples given hereinafter solely by way of illustration.
The polyholosides used are, in particular, glycosaminoglycans which are structural glycosaminoglycans selected from the group consisting of chondroitine-4-sulfate, chondroitine-6-sulfate, dermatane-sulfate, heparane-sulfate and keratane-sulfate, as well as heparin and its derivatives, particularly the derivatives of low molecular weight whose molecular weight can vary between 2,000 and 10,000. Chitosan and dextrane can also be used as polyholosides.
The polyholoside is used in particular in the forrn of aqueous solution at 0.5 to 4% and preferably 0.5 to 2%, and preferably still about 1%, by weight,with respect to the polyholoside solution.
The collagen, or preferably the atelocollagen, is preferably used in aqueous solution with a collagen or atelocollagen concentration comprised between 0.5 and 2% by weight. This solution of collagen or atelocollagen can be obtained by dissolving collagen or atelocollagen fibers in a slightly acid aqueous solution. Said slightly acid aqueous solution can be preferably an aqueous acid solution of 0.1 M acetic acid. The atelocollagen can be obtained by enzymatic digestion of collagen wellknown to the man skilled in the art.
To prepare the mixture of collagen, and preferably atelocollagen, polyholoside, the polyholoside solution is advantageously introduced into the collagen and preferably atelocollagen solution. Then, the solid particles, in particular the microcapsules, are prepared according to a preparation method by interfacial crosslinking such as described in document FR-B1-2 642 329.
According to said methods, after homogeneously mixing the solution of collagen, preferably atelocollagen, with the polyholoside solution, an oily phase 2 ~ ~22~ `
.
containing a crosslinking agent in dispersed phase form is dispersed into the continuous phase formed by the solution of a mixture of collagen, preferably atelocollagen and polyholoside, under stirring for the time required to obtain asuitable degree of interfacial c}osslinking, thus permitting the production of 5 microcapsules whose wall is a mixed wall of crosslinked collagen, preferably atelocollagen, and crosslinked polyholoside. ` `
The microcapsules are separated in an appropriate way by a natural decantation after one or more washings if necessary.
It is also possible to proceed by extrusion of a laminar flow through an 10 extrusion nozzle, the laminar flow being subjected to vibrations so as to form individual droplets which thereafter drop into a crosslinking bath cointaining the crosslinking agent.
Acid chloride, acid anhydride, or a dibasic or polybasic carboxylic acid are advantageously used as crosslinking agent. A preferred crosslinking agent is15 selected from the group consisting of terephtaloyl chloride, a phtaloyl chloride, a sebacoyl chloride, a succinyl chloride, a chloride of a tricarboxylic acid such as citric acid or an acid anhydride such as succinic anhydride.
A hydrophobic liquid is used as solvent of the crosslinking agent, in which liquid collagen, preferably atelocollagen and/or polyholoside, are insoluble.
20 Cyclohexane or chloroforrn, are still preferably used.
Due to the use of an interfacial crosslinking method, it is thus possible to prepare microcapsules which can encapsulate any kind of active ingredient. Inparticular, it is advantageous to encapsulate in the microcapsules a magnetic particle such as an iron oxide, this enabling easy separation of the solid substrate 25 from the solutions to be analyzed and constituting an important technical advantage of the invention. Indeed, a separation time less than S secs. is obtained over a 1 cm distance in the presence of a simple permanent magnet. This is due to their relatively important mass linked to a density close to 1 which requires only a small charge of magnetic oxide about 1% by weight, to reach that result. Then, 30 magnetic stirring becomes possible. The solid substrate according to the invention has a relatively high volume which makes it unresponsive to the aggregation forces, whether of hydrophobic or ionic nature. This further enables rapid separation during production by low speed centrifuging, such as for example around 800 g for 2 mins., and resuspension in non-aggregated form by simple 35 stirring.
2 2 ~
The particlcs of the solid substrate according to the invention can be obtained in interrnediate size for example of about 50 ~an, due to the production method used, particularly interfacial crosslinking, thus enabling sufficient reacting surfaces to be obtained during an immunoassay (for example 625 mm2 for 50,ul of 5 particles of solid substrate in suspension at 10% by weight). Said external surface is permanently in contact with the reaction liquid. Therefore, it is an extremely efficient surface.
The particles of the solid substrate according to the invention are hydrophilic by nature, because of its chemical constitution. It is known that the 10 polyholosides are chain forrnations of sugars havin~ in their structure numerous hydrophilic functions. Moreover, it is also possible to incorpoIate chito3an as polyholoside, thus enabling solid particles to be obtained, which particles have a low ionic charge.
Moreover, the chemical covalent bonding according to the invention 15 also enables graftings to be obtained, whic i1 graftings are s~rongly bonded, stable, and fixed in a selected direction, for example and advantageously for boncling peptides, this af~ording a maximum efficiency of reaction.
Other objects, characteristics and advantages of the invention will be more clearly understood from the following explanatory description given with 20 reference to several examples of embodiment which are given solely for illustration purposes and therefore which cannot possibly limit the invention in any way.
In the examples, all the percentages are given by weight, except othelwise stated.
25 Example 1 according to the invention Bonding of polyclonal antibody with solid magnetic particles by EDC
(1-ethyl-3-(3-dimethylaminopropyl)carbodiimide): application to the detection of human rotavirus in the stools.
1. Preparation of the solid particles (in microc~psule form) 30 Principle:
Solid particles of average size, about 50 ,um, were prepared and crosslinked after emulsion in an aqueous solution of atelocollagen and chitosan in an oily phase. Said prcparation was made according to the method described in Example 1 of FR-B1-2 642 329 (89-01221). The incorporaIi~-n of magnetic iron 35 oxide (FE304) makes it possible to obtain a solid phase separable by action of a magnetic field.
2 ~ 2 4 ~ -g Mode Operandi To a 1.6% solution of atelocollagen are added 10% of a 3% solution of KITAN in lactic acid. The atelocollagen is prepared according to the method described in French Patent No. 89 01221.
S The KITAN~ is supplied by the company ABER TECE~NOLOGIES, Prat Menau 29880 Plouguemeau France. The KITAN is a chitosan of molecular mass 1,200,000 daltons, having a desacetylation rate of 2.4%.
To the atelocollagen-Kitan mixture is added a 5% concentration of sodium carbonate. The pH is then adjusted to 8.0 with HCI N/10. In this preparation, 1% iron oxide Fe304 is introduced. 100 g of the resulting mixture are emulsified in 3900 ml of DRAGOXAT(~' sold by the German company DRAGOCO and containing 5% of SP~N 85~9 sold by ICI COMPANY. The emulsion is obtained by quick stirring with an Ultra Turax R stirring system, turning at 15,000 rpm for 2 hours.
400 Ml of DRAGOXAT~) containing the crosslinking agent, i.e. 2.5%
terephtalic acid chloride are added to the emulsion kept under stirring for 30 mins.
at 15,000 rpm.
The crosslinking agent is eliminated by centrifuging at 1,500 g for 10 mins. and by rejection of the resulting supernatant.
Three successive washings are carried out with 400 ml of DRAGOXAT~', the collagenic capsules being recovered by centrifuging in the same conditions as before. Six washings, using each time 600 ml of ethanol are carried out in order to remove the residual DRAGOXAT. Two washings with 60 ml of a soda solution at pEI 9 and three washings with de-ionized water enable the removal of the aggregates of capsules. A deposit of solid particles is thus obtained after centrifuging at 1,500 g for 10 mins.
Said deposit is then dispersed in an equal volume of de-ionized water containing 0.01 % of sodium mercurothiolate. Such dispersion of solid particles will be that used in the detections and assays described he}eunder.
2. Preparation of a specific reactant for an immunoassay Anti-rotavirus antibodies of gamma G type are used, which antibodies are purified from a hyperimmunized rabbit serum by a suspension of bovine rotavirus. The presence of anti-antigen antibodies of the virus group enables the detection of the human virus. The purity of the gamma globulins is checked by electrophoresis. The protein assay in weight/volume is effected by Lowry's technique.
-` 211~2`~
Tl.e bol~ding of the antibodies on the solid magnetic particles obtained in stage 1 hereinabove is performed by using the carboxylic functions (-COOH) ofcollagen.
The solid particles are washed beforehand in a buffer of pH close to 5 neutrality (comprised between 7 and 7.5) of low ionic strength and free from amine (such as for example: 10 mM Hepes buffer).
The solid particles are activated by a soluble carbodiimide (for example EDC (1-ethyl-3-(3-dimethylaminopropyl)carbodiimide) at a concentration varying between S and 100 mM (for example 20 mM) diluted in the 10 10 mM Hepes buffer.
The proportion will be 1 volume of solid magnetic particles for 1 -volume of EDC. The activation will take place under moderate stirring (for example on a rotary agitator) of the suspension for 1 hour between 20 and 25-C.
The excess of EDC is thereafter eliminated by washing of the solid particles in a 10 15 mM Hepes buffer (4 successive washings by addition of 9 volumes of buffer) and recovery of the solid particles by centrifuging or by magnetism.
The bonding of the garnma G of the rabbit (dialyzed beforehand in a 0.15 M Na solution) is performed by adding to the last centrifugation pellet 1 volume of 0.1 M carbonate-bicarbonate buffer and 1 mg of gamma G per ml of 20 pellet. The bonding is performed at room temperature on a rotary agitator for one hour. - -~
Blocking of the residual functions is performed by adding 10% of the total volume of a 1 M ethanolamine solution, of pH 9.0, and by stirring for one hour at between 20 and 25-C.
A se~uence of 4 final washings with a 50 mM Tris buffer enables the elimination of the antibodies which have not been reacted and the 10%
resuspension in said buffer makes it possible to obtain the final suspension of the specific reactant which is sought.
3. Detection of a specific element (forming reactant obtained in stage 2 above) This preparation has been tested with regard to positive- and negative-labelled human stools for tracing the rotavirus. This prior classification was made with a reacting kit of the conventional ELISA type available on the market. The protocole of the immunological reaction with the aforesaid reactant of magnetic solid particles is as follows:
:
`~ 2 2 ~
" 11 - dilution of the stools to 3/30 in 50 mM Tris buffer - pH 7.4.
Homogenization by stirring followed by centrifuging for 5 mins. to decant the fecal matter;
- bringing together 400 ,c~l of supernatant and 40 ,ul of 10% reactant of solid magnetic particles;
- stirring for 20 mins on an oscillating agitator;
- quick washings with 1 ml of Tween PBS buffer (Phosphate Buffer Saline) and separation of the solid phase by magnetization;
- placing the recovered reactant of solid magnetic particles in contact with 500 ,ul of a monoclonal anti-rotavirus antibody; called "revealing" becauseconjugated with peroxydase;
- stilIing for 20 mins on an oscillating agitator;
- quick washings with 1 ml of Tween PBS buffer, separation of the phases by magnetization;
- revelation of the enzymatic activity by a chromogenous substrate:
H20210rthophenylenediamine .
Reading is done visually, coloring intensity being assessed in +, see Table I below.
TABLE I
Stools Coloring Interpretation A 0 negative B ++++ positive C ++ t+ positive D 0 negative Examl)le 2 according to the invention Bonding of polyclonal antibodies to solid magnetic particles using EDC: application to assaying HCG (Human Chorionic Gonadotrophin) in serum.
The anti-HCG antibodies used are of gamma G type and are purified 35 from serum from a rabbit hyperimmunized by total purified HCG. Said antiserum -`
~`
2~ 1422~
therefore comprises antibodies of specificity a and ~. The bonding was performedaccording to the same protocole as in Example 1.1 and 1.2.
The reactant-fonning preparation was tested with regard to human sera of pregnant women previously classified with the aid of a conventional ELISA kit5 found on the market. Two sera from masculine donors were used as negative control.
The protocole of the immunological reaction with the sensitized solid magnetized particles is as follows:
- bringing together 50,ul of undiluted serum and 40,ul of reactant of 10 solid magnetic particles at 10%;
- stirring for 15 mins. on an oscillating agitator;
- addition of 100,ul of an anti-HCG monoclonal antibody (specificity ~3) conjugated with peroxidase;
- stirring for 15 mins. on an oscillating agitator; -;
- quick washings with 1 ml of Tween PBS buffer, separation of the phases by magnetization;
- revelation of the enzymatic activity by H2O2/ortho-phenylenediamine .
Reading is done on a spectrophotometer at 492 nm after blocking of 20 the enzymatic reaction with 1 ml of sulfuric acid, see Table II below:
TABLE II
Assay of HCG in human sera II-A
Sera from pregnant women D0 (492 nm) 0.544 2 0.900 3 1.45 ,. . : . :. . ~ :
, 21~22~
`` 13 II-B
Sera from masculine donors S a 0.096 b 0.106 Standard sera 5 mUI*
(threshold of positivity) 0.153 * mUI = International milli unit Conclusion The OD of the five positive sera is proportional to the concentration of the 15 HCG present.
The sera from masculine donors are unquestionably negative (<threshold).
The solid magnetic particles are usable for a quantitative determination.
~'; ' '';'' ;~
;`:
: ` :' . : : '', ::. : : . ~ : :
:
`~ 2 2 ~
" 11 - dilution of the stools to 3/30 in 50 mM Tris buffer - pH 7.4.
Homogenization by stirring followed by centrifuging for 5 mins. to decant the fecal matter;
- bringing together 400 ,c~l of supernatant and 40 ,ul of 10% reactant of solid magnetic particles;
- stirring for 20 mins on an oscillating agitator;
- quick washings with 1 ml of Tween PBS buffer (Phosphate Buffer Saline) and separation of the solid phase by magnetization;
- placing the recovered reactant of solid magnetic particles in contact with 500 ,ul of a monoclonal anti-rotavirus antibody; called "revealing" becauseconjugated with peroxydase;
- stilIing for 20 mins on an oscillating agitator;
- quick washings with 1 ml of Tween PBS buffer, separation of the phases by magnetization;
- revelation of the enzymatic activity by a chromogenous substrate:
H20210rthophenylenediamine .
Reading is done visually, coloring intensity being assessed in +, see Table I below.
TABLE I
Stools Coloring Interpretation A 0 negative B ++++ positive C ++ t+ positive D 0 negative Examl)le 2 according to the invention Bonding of polyclonal antibodies to solid magnetic particles using EDC: application to assaying HCG (Human Chorionic Gonadotrophin) in serum.
The anti-HCG antibodies used are of gamma G type and are purified 35 from serum from a rabbit hyperimmunized by total purified HCG. Said antiserum -`
~`
2~ 1422~
therefore comprises antibodies of specificity a and ~. The bonding was performedaccording to the same protocole as in Example 1.1 and 1.2.
The reactant-fonning preparation was tested with regard to human sera of pregnant women previously classified with the aid of a conventional ELISA kit5 found on the market. Two sera from masculine donors were used as negative control.
The protocole of the immunological reaction with the sensitized solid magnetized particles is as follows:
- bringing together 50,ul of undiluted serum and 40,ul of reactant of 10 solid magnetic particles at 10%;
- stirring for 15 mins. on an oscillating agitator;
- addition of 100,ul of an anti-HCG monoclonal antibody (specificity ~3) conjugated with peroxidase;
- stirring for 15 mins. on an oscillating agitator; -;
- quick washings with 1 ml of Tween PBS buffer, separation of the phases by magnetization;
- revelation of the enzymatic activity by H2O2/ortho-phenylenediamine .
Reading is done on a spectrophotometer at 492 nm after blocking of 20 the enzymatic reaction with 1 ml of sulfuric acid, see Table II below:
TABLE II
Assay of HCG in human sera II-A
Sera from pregnant women D0 (492 nm) 0.544 2 0.900 3 1.45 ,. . : . :. . ~ :
, 21~22~
`` 13 II-B
Sera from masculine donors S a 0.096 b 0.106 Standard sera 5 mUI*
(threshold of positivity) 0.153 * mUI = International milli unit Conclusion The OD of the five positive sera is proportional to the concentration of the 15 HCG present.
The sera from masculine donors are unquestionably negative (<threshold).
The solid magnetic particles are usable for a quantitative determination.
~'; ' '';'' ;~
;`:
: ` :' . : : '', ::. : : . ~ : :
Claims (15)
1. Use of collagen, preferably atelocollagen, and better still an atelocollagen-polyholoside mixture, as solid binding substrate for a sensor, known as ligand or refining agent, capable of specifically reacting with an element to be detected in a biological medium to form a specific complex which can be detectedby any detection means.
2. Use according to claim 1, characterized in that the collagen is in the form of particles, spheres or capsules, preferably of diameter ranging between 5 and 500 µm.
3. Use according to claim 1 or 2, characterized in that the collagen, preferably the atelocollagen, is combined to a polyholoside; advantageously the relative proportion of polyholoside with respect to the atelocollagen is comprised between 15 and 50% by weight.
4. Use according to one of claims 1 to 3, characterized in that the particles ofcollagen contain a magnetic oxide, preferably a magnetic iron oxide.
5. Use according to claim 4, characterized in that the magnetic oxide concentration is comprised between 0.1 and 10% by weight.
6. Use according to one of claims 1 to 5, characterized in that a sensor is covalently bonded by a chemical agent, to the solid substrate.
7. Use according to claim 6, characterized in that the bonding is performed with amino functions and/or with carboxylic functions and/or with alcoholic functions of the collagen and/or of the polyholoside.
8. Use according to one of claims 1 to 7, characterized in that the polyholoside is advantageously a structural glycosaminoglycan, selected from thegroup consisting of chondroitine-4-sulfate, chondroitine-6-sulfate, dermatane-sulfate, heptarane sulfate, ketarane-sulfate and heparin and its derivatives, inparticular the heparins of low molecular weight whose molecular weight is comprised between 2,000 and 10,000; the chitosan and dextrane.
9. Use according to one of claims 1 to 8, characterized in that said sensor is selected from an antibody, an antigen, in soluble or particulate form, in particular a human anti-rotavirus antibody or an anti-HCG antibody.
10. Use according to one of claims 1 to 9, characterized in that said solid substrate has multiple specificity.
11. Biological reactant, characterized in that it comprises as solid substrate, collagen, preferably atelocollagen, and better still a mixture of atelocollagen and polyholoside, on which is bonded a sensor forming ligand or refining agent, specific of an element to be detected in a biological medium.
12. Reactant according to claim 11, characterized in that the solid substrate isdefined according to any one of claims 2 to 10.
13. Method for the detection of an element present in a biological medium, characterized in that the biological reactant used is a biological reactant according to any one of claims 2 to 10.
14. Method according to claim 13, characterized in that the biological reactant used is a biological reactant whose sensor comprises a human anti-rotavirus antibody, and in that the method is a method for detecting the human rotavirus.
15. Method according to claim 13, characterized in that the biological reactant used is a biological reactant whose sensor is an anti-HCG antibody, andin that the method is a method for assaying HCG in the serum.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| FR919109819A FR2680005B1 (en) | 1991-08-01 | 1991-08-01 | USE OF COLLAGEN AS A SOLID SUPPORT FOR FIXING A SENSOR CAPABLE OF REACTING SPECIFICALLY WITH AN ELEMENT TO BE DETECTED IN A BIOLOGICAL, REACTIVE AND IMPLEMENTING METHOD. |
| FR91/09819 | 1991-08-01 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2114224A1 true CA2114224A1 (en) | 1993-02-02 |
Family
ID=9415836
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002114224A Abandoned CA2114224A1 (en) | 1991-08-01 | 1992-07-30 | Use of collagen as a solid binding substrate for a specific sensor |
Country Status (7)
| Country | Link |
|---|---|
| EP (1) | EP0598014B1 (en) |
| JP (1) | JPH07503534A (en) |
| AT (1) | ATE128236T1 (en) |
| CA (1) | CA2114224A1 (en) |
| DE (1) | DE69205005T2 (en) |
| FR (1) | FR2680005B1 (en) |
| WO (1) | WO1993003373A1 (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| AT403963B (en) * | 1996-12-18 | 1998-07-27 | Immuno Ag | Method for quantifying and determining the functionality of collagen-binding proteins |
| FR2777193B1 (en) * | 1998-04-14 | 2001-06-08 | Coletica | PARTICLE WITH A CHELATING HYDROXAMIC GROUP OF METAL IONS AND THEIR USE IN COSMETICS OR PHARMACY |
Family Cites Families (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4169804A (en) * | 1976-08-19 | 1979-10-02 | Minnesota Mining And Manufacturing Company | Magnetically responsive composite microparticle |
| DE2929144A1 (en) * | 1979-07-19 | 1981-02-12 | Behringwerke Ag | METHOD FOR PRODUCING COLLAGEN |
| SE441009B (en) * | 1982-03-08 | 1985-09-02 | Kjell Nilsson | WAY TO IMMOBILIZE LIVING BIOMATERIAL IN PEARLY POLYMERS |
| FR2642329B1 (en) * | 1989-01-31 | 1991-05-24 | Bioetica Sa | USE OF ATELOCOLLAGEN AND GLYCOSAMINOGLYCAN SOLUTIONS FOR THE MANUFACTURE OF MICROCAPSULES, MICROCAPSULES MADE THEREOF, METHODS OF MANUFACTURING SUCH MICROCAPSULES AND COSMETIC OR PHARMACEUTICAL OR FOOD COMPOSITIONS CONTAINING THE SAME |
| US5252496A (en) * | 1989-12-18 | 1993-10-12 | Princeton Biomeditech Corporation | Carbon black immunochemical label |
| CA2031659A1 (en) * | 1990-01-26 | 1991-07-27 | John B. Findlay | Water-insoluble reagent, nucleic acid probe, test kit and diagnostic and purification methods |
-
1991
- 1991-08-01 FR FR919109819A patent/FR2680005B1/en not_active Expired - Lifetime
-
1992
- 1992-07-30 DE DE69205005T patent/DE69205005T2/en not_active Expired - Lifetime
- 1992-07-30 EP EP92917551A patent/EP0598014B1/en not_active Expired - Lifetime
- 1992-07-30 JP JP5503329A patent/JPH07503534A/en active Pending
- 1992-07-30 WO PCT/FR1992/000749 patent/WO1993003373A1/en active IP Right Grant
- 1992-07-30 CA CA002114224A patent/CA2114224A1/en not_active Abandoned
- 1992-07-30 AT AT92917551T patent/ATE128236T1/en not_active IP Right Cessation
Also Published As
| Publication number | Publication date |
|---|---|
| EP0598014B1 (en) | 1995-09-20 |
| WO1993003373A1 (en) | 1993-02-18 |
| JPH07503534A (en) | 1995-04-13 |
| DE69205005T2 (en) | 1996-03-21 |
| ATE128236T1 (en) | 1995-10-15 |
| DE69205005D1 (en) | 1995-10-26 |
| FR2680005B1 (en) | 1994-09-02 |
| FR2680005A1 (en) | 1993-02-05 |
| EP0598014A1 (en) | 1994-05-25 |
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| Date | Code | Title | Description |
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| EEER | Examination request | ||
| FZDE | Discontinued |