JP2007308863A - Fiber, fibrous aggregate, fibrous adsorbing material and method for producing fiber - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fiber, fibrous aggregate and fibrous adsorbing material, capable of well adsorbing harmful substances for a human body, and a method for producing the fiber. <P>SOLUTION: This fiber contains ≥1% and ≤60% double stranded DNA. The production device of the fiber is a static spinning device and an electric voltage-impressing roll 20 is installed in a dissolved liquid immersion vessel 10 housing a DNA solution. A high electric voltage-generating device 21 is joined with the dissolved liquid immersion vessel 10. At the opposing position to the electric voltage-impressing roll 20, an integral conveyer 30 is arranged so as to face its integrating surface 30A toward the electric voltage-impressing roll 20 side, and a block made from a metal 31 is arranged in a position of facing to the electric voltage-impressing roll 20 by placing the integral conveyer 30 in between. By joining the block made from the metal 31 with the high electric voltage-generating device 21, a static electric field is formed between the electric voltage-impressing roll 20 and the block made from a metal which become electrodes. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a fiber, a fiber assembly, a fiber adsorbent, and a method for producing a fiber that adsorb human harmful substances such as tobacco and exhaust gas.

There are substances that cause harm to the human body, and typical examples include environmental hormones and carcinogenic substances. In particular, tobacco contains carcinogenic substances such as dioxins and benzopyrene that damage genes, and its danger is well known. Since these components have an adverse effect on the human body even in a very small amount, it is an important issue to effectively absorb and collect human harmful substances with a filter.
2. Description of the Related Art Conventionally, there is a dioxin removal technique (Patent Document 1) having a filtration function of ultrafine fibers constituting a filter and an adsorption mechanism using activated carbon.

  In recent years, the demand for double-stranded DNA has increased, and various techniques have been developed. For example, as a technique for removing harmful substances such as dioxins and carcinogenic substances using double-stranded DNA, there is an adsorbent in which DNA is immobilized on acrylamide hydrogel (Patent Document 2). Since DNA has a double helix structure, a polycyclic compound having a planar structure is inserted (intercalated) between base pairs. Since dioxins that are harmful to human bodies have a planar structure, this intercalation can be incorporated between DNA base pairs to remove harmful human substances.

A fiber using DNA has also been developed (Non-patent Document 1). In general, the functional component is added to the fiber by coating with a binder or by kneading into a fiber raw material.
In addition, as fibers using natural products, ultrafine fibers using starch (Patent Documents 3 and 4) and peptide nanofibers (Patent Document 5) have been proposed.

JP 2002-239347 A JP2005-161104 JP 2002-201556 A JP2002-201531 JP-A-2005-146462 Fang etal., J. Macromol. Sci.-Phys., B36 (2), 169-173 (1997)

However, since Patent Document 1 aims to remove dioxins in waste water, it is not applied to human harmful substances existing other than liquids, and is limited to specific harmful substances. Also in Patent Document 2, it is effective only for human harmful substances in a liquid, and since a contact area is small, a column is required, so that generalization is difficult.
Non-Patent Document 1 describes a fiber using DNA, but this fiber is not intended for removing human harmful substances and has a low DNA content.

In the ultrafine fibers using starch of Patent Document 3 and Patent Document 4, spinnability is affected by starch composition concentration, temperature, etc., and biomaterials such as DNA are not easily produced.
In Patent Document 5, peptide nanofibers are fibrous particles due to the self-organizing action of peptides, and this has not led to the production of industrial fibers containing a high amount of DNA.

  By the way, some of the fish larvae are used for feed and fertilizer, and most of them are disposed of, and over 10,000 tons per year. Therefore, effective utilization of resources is required. In recent years, functional proteins have been widely used in food applications due to an increase in health consciousness. Among them, DNA extracted from Shirako is expected to be used as a biocompatible material for medical and pharmaceutical materials, as well as for health filters and electronic parts that use support and adsorption. However, restructuring this biomaterial as a molding material, particularly as a long fiber aggregate, has hardly been industrially established, and expansion of utilization is demanded from the viewpoint of the global environment.

  An object of the present invention is to provide a fiber, a fiber assembly, a fiber adsorbent, and a method for manufacturing a fiber that can satisfactorily adsorb human harmful substances and can be easily manufactured.

The fiber of the present invention contains double-stranded DNA in an amount of 1% to 60%.
In the present invention, human harmful substances are adsorbed and collected by utilizing the nature of intercalation between base pairs between DNA double helix structures.
According to this invention, since 1% or more of double-stranded DNA is blended in the fiber, the amount of the harmful substance to be taken in between the base pairs is increased, and the ability to absorb and collect the harmful substance is excellent. On the other hand, RNA, for example, nucleotides and polynucleotides do not have double strands, and therefore have no ability to adsorb harmful substances.
And even if it has DNA which has a double strand, if it is less than 1% of content, the quantity by which a human body harmful | toxic substance will be taken in between base pairs is not enough. Further, when the content of the double-stranded DNA exceeds 60%, it is difficult to spin. In order to remove harmful substances, it is better that the content of double-stranded DNA is high, but since the fiber becomes brittle, its practicality is limited.
Therefore, the double-stranded DNA is excellent in adsorption and collection performance, and the DNA is effective because it can effectively utilize the discarded white child, and also has a skin healing ability as a fiber material that touches the skin.

The fiber assembly of the present invention is characterized by assembling the fibers.
In the invention of this configuration, it is possible to provide a fiber assembly that can achieve the above-described effects.

The fiber adsorbent of the present invention comprises the fiber assembly and adsorbs harmful substances.
In the invention of this configuration, it is possible to provide a fiber adsorbent that can achieve the above-described effects.

The fiber production method of the present invention is characterized in that it is produced by an electrostatic spinning method in which the DNA solution is charged and spun.
According to this invention, since the electrospinning method can be spun at room temperature, the thermal decomposition of DNA can be suppressed, and even if the medium is water, the spinning can be performed, so that a safe product can be produced. In this method, the increase in the charge promotes the thinning of the yarn, and the volatilization of the solvent proceeds along with the thinning, so that it is possible to obtain an ultrafine fiber highly blended with DNA.

In the fiber manufacturing method of the present invention, it is preferable that the DNA solution is housed in a dissolution liquid immersion tank and the fibers are spun using a voltage application roll installed in the dissolution liquid immersion tank.
According to this invention, since the voltage application roll is used, the solution on the roll surface immersed in the liquid layer is spontaneously pulled by electrostatic attraction, whereby spinning is performed. Therefore, compared with the case where the nozzle is used even in the same electrospinning method, the problems of nozzle clogging due to aggregation, poor appearance due to liquid mass, and uneven opening due to repulsion between fibers can be solved. A good product can be obtained without reducing the productivity of the double-stranded DNA fiber.

Hereinafter, an embodiment of the present invention will be described.
[Fiber, fiber assembly, fiber adsorbent]
The fiber according to the present embodiment contains double-stranded DNA, and this fiber is assembled to form a fiber assembly. This fiber assembly is used as a fiber adsorbent that adsorbs harmful substances, and is used, for example, as an adsorbing and collecting filter for human harmful substances such as tobacco and exhaust gas.

<About DNA>
DNA is a high molecular compound that exists in biological cells and preserves genetic information of living organisms. It consists of two polynucleotide chains having a double helix structure with four bases of adenine, thymine, guanine and cytosine as constituent elements. In this duplex, planar bases having structural complementarity protrude perpendicular to the axis of the helix toward the center of the helix and are bonded by hydrogen bonds. Due to such a structure, DNA has a feature of inserting (intercalating) a polycyclic compound having a planar structure between base pairs.
Dioxins, which are harmful to human body, have a planar structure and are intercalated between base pairs and incorporated into DNA. The present invention uses such properties of DNA.

<Purification of DNA>
The DNA used in the present embodiment may be any DNA as long as it is derived from a natural product. However, it is preferably obtained from a fish larva treated as a marine waste material.
DNA can be obtained by removing skin, muscles, blood vessels, etc. from the larva and purifying it to remove oil. Double-stranded DNA is purified by conventional methods (Yasuo Umehara, “DNA Isolation Technology—New Functional Materials”). Development of DNA Mass Separation / Purification Technology as "-" Polymer 52 Vol. March (2003) P.130-133, JP-A-2005-245394).
Shiroko contains a large amount of double-stranded DNA along with proteins such as protamine, and is a very nutritious food, but its application field is limited due to difficulty in processing and short shelf life. Most of them are disposed of. Therefore, the fish larva can be effectively used as a raw material for inexpensive mass production of double-stranded DNA.

<Preparation of DNA solution>
In the present embodiment, finely pulverized water-soluble DNA and protein-bound water-insoluble DNA extracted and dried can be dispersed in water and used as a water slurry. In this case, the double helix of the double-stranded DNA is maintained in each case, so that the ability to adsorb human harmful substances can be maintained.

In this embodiment, a DNA solution diluted with a binder and a solvent can be prepared as necessary.
Known binders can be used here, such as polyurethane, silicone, polyvinylidene fluoride, polyacrylonitrile, polymethyl methacrylate, polyvinyl chloride, polyvinylidene chloride, polyethylene, polypropylene, nylon, polyvinyl alcohol, cellulose, poly Vinyl acetate, polypropylene oxide, polyethyleneimide, polyaniline, polyethylene sulfide, polystyrene, polybutadiene, polyvinyl alcohol, polyethylene terephthalate, polyethylene oxide, collagen, polylactic acid, polyglutamic acid, hyaluronic acid, and their copolymers and crosslinks Examples include polymers that can be dissolved in a solvent, including the body. Further, natural polymers such as starch, casein, gelatin, sericin, fibroin, chitin and chitosan, and sol solutions such as organosilica and organotitanium can be mentioned.

  In addition, water is usually used as a medium in which DNA is dispersed and dissolved, but in addition to that, a medium capable of dissolving the above-mentioned constituents is appropriately selected. Examples include acid, alkali, methanol, ethanol, propanol, isopropanol, acetone, ether, toluene, tetrahydrofuran, cyclohexane, N, N-dimethylformamide, N, N-dimethylacetamide, dimethyl sulfoxide, chloroform and the like. Ethanol and ketones are prone to agglomerate and spinning may be difficult, but it is only necessary to disperse and dissolve double-stranded DNA, and use these as a mixed solvent of two or more types in view of spinnability. Can do.

The solid content of the constituent component is preferably 0.1 to 20% with respect to the medium, and substantially 1 to 10% is easily spun. If necessary, surfactants, metal salts, thickeners, colorants, and various stabilizers can be used as appropriate. When the solid content of the constituent component is less than 0.1%, it cannot be spun into a yarn or the productivity is poor. If it exceeds 20%, the viscosity will increase and spinning will not be possible.
The DNA content of the spun fiber is preferably 1% or more, and more preferably 10% or more. Among these, it is preferable that 3% or more of DNA that can substantially take a double helix structure is contained.
The above ratio is balanced with the binder according to the purpose. However, when the DNA content is less than 1%, the performance is poor, and the amount of the human harmful substance incorporated between the base pairs is not sufficient. Further, the DNA content is preferably 60% or less from the viewpoint of ease of spinning.

[Fiber manufacturing equipment]
Next, a fiber manufacturing apparatus according to an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a perspective view schematically showing a fiber manufacturing apparatus according to an embodiment of the present invention, and FIG. 2 is a schematic sectional view of FIG.
1 and 2, the fiber manufacturing apparatus is an electrostatic spinning apparatus, and a voltage application roll 20 is installed in a solution immersion tank 10 containing a DNA solution.
The voltage application roll 20 is rotatably supported in the solution immersion tank 10, and at least the peripheral surface portion is made of metal. A high voltage generator 21 is connected to the lysing bath 10, and a voltage is applied from the power source 21, the DNA solution is charged positively, and the voltage is concentrated by the voltage application roll 20. The voltage application roll 20 is connected to a rotation drive mechanism (not shown).

An accumulation conveyor 30 is disposed at a position facing the voltage application roll 20 with the accumulation surface 30A facing the voltage application roll 20 side. Further, a metal block 31 is disposed at a position facing the voltage application roll 20 with the stacking conveyor 30 interposed therebetween, and the metal block 31 is connected to the high voltage generator 21 and is negatively charged.
The accumulation conveyor 30 is a non-woven fabric made of a conductive material, for example, a band-shaped member made of aluminum or the like, or a paper or synthetic fiber that does not hinder the conductivity of the metal block 31, and is fed from a feed roll (not shown). It is the structure wound up with the winding roll which is not shown in figure.
Guide rolls 32 are respectively arranged before and after the metal block 31 in the flow direction of the accumulation conveyor 30.
The distance between the voltage application roll 20 and the stacking surface 30A of the stacking conveyor 30 is not particularly limited as long as it is freely selected while observing the state of yarn accumulation so that the solvent is vaporized. The applied voltage may be changed depending on the properties of the solution and the amount of deposition. The higher the voltage, the easier to obtain a large amount of fibers. Therefore, the voltage application roll 20 and the metal block 31 serve as electrodes, an electrostatic field is formed between them, and the DNA solution attached to the voltage application roll 20 is drawn out from the roll surface toward the metal block 31 in a thread shape, Deposited on the accumulation surface 30A.

[Fiber manufacturing method]
Next, an embodiment according to a fiber manufacturing method will be described. The fiber manufacturing method of this embodiment is an electrostatic spinning method using the electrostatic spinning device shown in FIGS. 1 and 2.
First, the DNA solution is stored in the dissolution liquid immersion tank 10 and the accumulation conveyor 30 is driven. Since the metal block 31 connected to the high voltage generator 21 is disposed close to the accumulation conveyor 30, when a high voltage is applied in this state, charges are induced and accumulated on the solution surface. This electrostatic attractive force opposes the surface tension of the DNA solution. When the electric field force exceeds the critical value, the electrostatic attractive force exceeds the surface tension, and a jet of charged solution is ejected. Since the jetted jet has a large surface area relative to the volume, the solvent is efficiently evaporated, and the charge density is increased due to the volume reduction, so that the jet becomes thinner. Spinning is performed by spontaneously pulling the metal block 31 side by jetting the solution.
The spun DNA fibers are deposited on the accumulation surface 30A of the accumulation conveyor 30. Since the accumulation conveyor 30 is wound up, the DNA fibers accumulated on the accumulation surface 30A have a predetermined thickness along the length of the conveyor. It becomes. The accumulated DNA fibers are peeled from the accumulation conveyor 30 by an apparatus (not shown).

[Effect of the embodiment]
Therefore, according to the present embodiment, the following operational effects can be achieved.
(1) The fiber contains 1% or more and 60% or less of double-stranded DNA. Therefore, since the double-stranded DNA is highly blended, it is excellent in the ability to adsorb and collect harmful substances. In addition, as a DNA, a white child that has been disposed of can be effectively used, and a fiber can be easily produced.

(2) In the present embodiment, the fiber manufacturing method is an electrostatic spinning method. Since the electrospinning method can spin at normal temperature, thermal decomposition of DNA can be suppressed, and spinning can be performed even if the medium is water, so that a safe product can be manufactured.

(3) In the present embodiment, the solution immersion bath 10 in which the DNA solution is immersed, the voltage application roll 20 disposed in the solution immersion bath 10, and the static electricity generated through the voltage application roll 20 The fiber manufacturing apparatus is configured to include an accumulation conveyor 30 on which the spun fibers are collected while being spun by attractive force. That is, in this embodiment, since the spinning is performed using the voltage application roll 20, compared with the case where the nozzle is used even in the same electrostatic spinning method, the appearance due to nozzle clogging due to DNA aggregation, liquid mass, or the like. There is no opening unevenness due to defects or repulsion between fibers, and a good product can be obtained without reducing the productivity of double-stranded DNA fibers.

It should be noted that the present invention is not limited to the above-described embodiments, and modifications, improvements, and the like within the scope that can achieve the object of the present invention are included in the present invention.
For example, in the above-described embodiment, the electrospinning method that can obtain ultrafine fibers without decomposing double-stranded DNA is used. However, as long as these objects can be achieved, the electrospinning method is not limited to other spinning methods. It may be a method.
Moreover, in the said embodiment, although the electrostatic field of an electrostatic spinning apparatus forms a pair of electrode with the voltage application roll 20 and the metal blocks 31, in this invention, this is increased and between several electrodes, You may form in a solution immersion tank. In this case, the voltage application rolls 20 may have different voltage values.

Hereinafter, the effect of the present invention will be confirmed by examples and comparative examples. In addition, this invention is not limited to these Examples, unless the summary is exceeded.
<DNA extraction, DNA powder preparation>
After thawing 250 g of frozen salmon roe and 3 L of a cold water solution of 1% sodium dodecyl sulfate with a mixer, 500 ml of a 2 mol / L sodium chloride aqueous solution was added and further lightly stirred. Boiled for about 5 minutes at 100 ° C., the protein was denatured and cured, and the cooled one was filtered with gauze. The filtrate was cooled in an ice bath and 3 times the amount of cold ethanol was added dropwise to recover the fibrous DNA. Ethanol was evaporated to obtain a DNA dried product. This DNA dried product was dissolved in a predetermined solvent and concentration to obtain a double-stranded DNA solution.
On the other hand, the filtrate is a water-insoluble double-stranded DNA to which protein is bound, and the water-washed and dried product is pulverized with a hammer mill having a slit diameter of φ1 mm and then finely pulverized with a jet mill. A water-soluble DNA powder was obtained. This powder is shown in FIG. FIG. 3 is a view of the water-insoluble DNA powder as seen with a scanning electron microscope. From this figure, it can be seen that the average particle diameter of the water-insoluble DNA powder is about 6 μm. This water-insoluble DNA powder 10% was dispersed in water, and the dispersion was treated twice at 150 MPa × using an optimizer HJP-25005 manufactured by Sugino Machine to prepare a water-insoluble double-stranded DNA slurry solution.

[Example 1]
A polyvinyl alcohol (PV-217PVA manufactured by Kuraray Co., Ltd.) having a viscosity of 23 mPa · s in a 4% aqueous solution with a Ken value of 88 mol% at 20 ° C. is used as a binder, and water / PVA / DNA using the above double-stranded DNA solution. = 90 / 9.9 / 0.1% DNA aqueous solution was prepared. The obtained solution was spun by the method described later to obtain 1.0% DNA-containing PVA fiber.

[Example 2]
Using the same PVA as in Example 1 and the above-mentioned double-stranded DNA solution, a small amount of phosphoric acid was added to impart spinnability, and water / PVA / DNA / phosphoric acid = 90.5 / 8.3 / A 1.1 / 0.1% aqueous DNA solution was prepared and spun as in Example 1. A PVA fiber containing 11.7% DNA was obtained.

[Example 3]
A 45% ethanol water / PVA / DNA = 94.0 / 3.9 / 2.1% aqueous DNA solution was prepared using the same PVA as in Example 1 and the double-stranded DNA solution described above. Spinning in the same manner as A PVA fiber containing 35.0% DNA was obtained.

[Example 4]
Using the same PVA as in Example 1, using the water-insoluble double-stranded DNA slurry solution described above, a 45% ethanol water / PVA / DNA = 91.7 / 3.7 / 4.6% aqueous DNA solution was prepared. Prepared and spun as in Example 1. A PVA fiber containing 55.4% DNA was obtained.

[Comparative Example 1]
Similar to Example 1, but using a DNA / water solution of water / PVA / DNA = 90 / 9.95 / 0.05%, the same treatment was carried out to obtain a PVA fiber containing 0.5% DNA.

[Comparative Example 2]
Deoxyribonuclease I (DNase I) was added to the aqueous DNA solution of Example 2 and allowed to stand at 40 ° C. for 2 hours. This was treated in the same manner as in Example 2 to obtain a PVA fiber containing 11.7% DNA.

[Comparative Example 3]
No binder was used, and an aqueous DNA solution of 45% ethanol water / DNA = 90/10% was used. Spinning was performed by the method described later to obtain a fiber containing 100% DNA.

[Comparative Example 4]
The solution obtained in Example 3 was injected into a φ0.5 syringe.

<Electrostatic spinning>
The solutions of Examples 1 to 4 and Comparative Examples 1 to 4 were charged on the liquid surface at a voltage of 60 to 78 kV and a distance between electrodes of 100 to 140 mm using the electrostatic spinning apparatus shown in FIGS. When the charge increased above the tension, the yarn spouted out from the cylinder surface. The jet repeats volatilization of the solvent, increase of charge density, and thinning of the solution yarn, and deposits on the accumulation conveyor. In addition, the line speed of the accumulation conveyor is 8 to 20 cm / min, and ultrafine fibers of 100 to 500 nm are deposited on a non-woven fabric made of polypropylene (PP) with a net weight of 0.5 to 4.0 g / m ² and cotton for adsorption evaluation. Was obtained (see FIG. 4).
In Comparative Example 4, spinning was performed with an electrostatic spinning apparatus using a nozzle.

<Adsorption and collection evaluation of harmful substances>
Acridine orange having an aromatic planar structure was used as a model compound in the same manner as dioxin for evaluating the adsorption and collection of harmful substances. Acridine orange is a fluorescent indicator used for DNA research. Since DNA has an action of staining orange and fluorescing with ultraviolet rays, if acridine orange is incorporated into DNA, the acridine orange solution will be discolored. The cotton obtained is immersed in an aqueous solution of acridine orange 5 μM / ml and left for 24 hours. The solution after immersion was measured for absorbance at 480 nm with a UV-VIS spectrophotometer, and the presence or absence of a decrease relative to the absorbance before immersion was evaluated.

In Examples 1 to 4, the spinnability was good and the absorbance of acridine orange was changed (indicated by ○ or Δ in Table 1). That is, it can be seen that the DNA contained in the obtained fiber has an acridine orange adsorption-capturing ability, and the DNA is not decomposed. Moreover, from the DNA content of the obtained fiber, a fiber with a high DNA content could be obtained.
On the other hand, in Comparative Example 1, the DNA content was very low, and in Comparative Example 2, since DNase I that enzymatically degrades DNA was used, DNA was degraded and no change was observed in the absorbance of acridine orange (Table). (Indicated by x in 1). In Comparative Example 3, spinning was not possible because there was no binder.
In Comparative Example 4, since an electrostatic spinning apparatus using a nozzle was used, clogging occurred.

  INDUSTRIAL APPLICABILITY The present invention can be used for an adsorption / collection filter for harmful substances such as tobacco and exhaust gas.

The perspective view which shows the outline of the manufacturing apparatus used for the manufacturing method of the fiber concerning one Embodiment of this invention. Sectional drawing of FIG. The figure which looked at the water-insoluble DNA powder with the scanning electron microscope. The figure which looked at cotton after spinning with the scanning electron microscope.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Dissolution bath 20 ... Voltage application roll 30 ... Accumulation conveyor 30A ... Accumulation surface

Claims (5)

  A fiber comprising 1% or more and 60% or less of double-stranded DNA.   A fiber assembly obtained by assembling the fibers according to claim 1.   A fiber adsorber comprising the fiber assembly according to claim 2 and adsorbing harmful substances. A method for producing a fiber for spinning the fiber according to claim 1,
A method for producing a fiber, which is produced by an electrostatic spinning method in which the DNA solution is charged and spun. In the manufacturing method of the fiber of Claim 4,
A method for producing a fiber, comprising: storing the DNA solution in a dissolution liquid immersion tank; and spinning the fiber using a voltage application roll installed in the dissolution liquid immersion tank.