CS225366B1 - Hydrophilic latex particles containing thiole groups and method of their preparation - Google Patents

Description

The invention relates to thiol-group-containing latex particles and to a process for their preparation in a simple manner without requiring special equipment or safety measures.

Hydrophilic latex particles find wide application in various fields of biochemistry, especially as carriers of biochemically or immunologically active substances. The prior art method of synthesizing latex particles capable of binding biochemically or immunologically active substances on their surface consists mainly in standard emulsion polymerization. The principle of conventional emulsion polymerization is generally known and consists in dispersing a water-sparingly soluble monomer or a mixture of water-sparingly soluble monomers in an aqueous emulsifier and initiator solution, heating the mixture to a temperature at which the chain polymerization initiating radicals are generated and maintaining the mixture at the desired temperature. with stirring for the time necessary to achieve a certain conversion. The polymerization itself takes place initially in colloidal formations called micelles in which the monomer is soluble, consisting of suitably sterically arranged surfactant molecules. After the polymerization is complete, the surfactant remains on the surface of the polymeric latex particles formed and thus stabilizes them against coagulation. Although removal of the emulsifier is largely possible, either the irreversible loss of the individual character of the discrete polymer particles by their aggregation during coagulation or at least the impossibility of restoring the particles to their original state occurs. This disadvantage of conventional latexes is eliminated by the use of the so-called emulsion-free emulsion polymerization technique in which the particles are autostabilized by ionogenic groups that are part of the polymer chain formed during the initiation reaction. The most recent example of this polymerization is the Cs process. No. 225010 describing the synthesis of latex hydrophilic particles by homo- or copolymerization of the monomers of the general formula

CH ₂ = CR 1 - X - CH ₂ - CH - CH ₂ \ /

Wherein R ₁ is hydrogen or methyl and X is -O- or -CO-O- in the absence of an emulsifier resulting in spherical polymer particles of the same size. These particles carry a number of reactive epoxy groups that can be used to attach biologically or immunologically active substances to the surface of the particles. The epoxy group undoubtedly fulfills a number of requirements for the synthesis of polymer-active substance conjugates, but the disadvantage is that the reaction itself proceeds relatively slowly. Long incubation may in some cases lead to a loss of biological or immunological activity. This can be avoided by using carriers whose functional groups are more reactive compared to epoxy, i.e. they react more rapidly under conditions in which immobilization can be realized due to the stability of immobilized substances.

One of the groups that satisfies the requirement for rapid and easy binding of a biologically active immunologic agent is the thiol group. The immobilization is usually carried out after activation, for example by dipyridyldisulphide, 6-maleimido-succinimide N-hydroxysuccinimide ester and the like. Of the protein groups, the thiol group of cysteine is involved. Since in many cases these groups may be essential for the activity of the immobilized substance, this technique should be chosen with particular caution.

Another equally important application of hydrophilic latexes containing sulfhydryl groups is the sorption of metal ions, such as mercury. This property allows rapid removal of unwanted ions from the solutions on the one hand or, on the other hand, the deliberate introduction of e.g.

The present invention relates to hydrophilic latex particles containing thiol groups, characterized in that they consist of polymerized units of the general formula I - CH ₂ - CR ¹ - I,

AND

X - CH ₂ -CH (OH) - CH ₂ -SH wherein R ¹ is hydrogen or methyl and X is -O- or -CO-O-, or a mixture of polymerized units of formula I and 1-99% by weight. units formed by the polymerization of monomers selected from the group consisting of glycidyl acrylate or methacrylate, alkyl or hydroxyalkyl acrylate or methacrylates, acrylamides or methacrylamides, styrene, divinylbenzene, N-vinylpyrrolidone, vinyl acetate, butadiene, isoprene and glycidyl vinyl ether.

The invention further provides a method for

Claims (2)

SUBJECT Hydrophilic latex particles containing thiol groups, characterized in that they consist of polymerized units of the general formula I, true hydrophilic latex particles containing thiol groups, characterized in that the latex particles consist of a homopolymer of glycidyl acrylate, glycidyl methacrylate or glycidyl vinyl ether or copolymers thereof or copolymers thereof. 99% wt. monomers selected from the group consisting of alkyl or hydroxyalkyl acrylates or methacrylates, acrylamides or methacrylamides, styrene, divinylbenzene, N-vinylpyrrolidone, vinyl acetate, butadiene and isoprene are reacted with hydrogen sulfide or alkali metal sulfide at temperatures up to 100 ° C. According to the method, the prepared particles are then freed of excess undesirable substances by evaporation or decantation in a centrifuge, dialysis or pressure filtration. In order to avoid coagulation by cross-reacting surface thiol groups, it is advisable to store the particles in a non-oxidizing environment. In the following, the invention is illustrated in more detail by means of exemplary embodiments. Example 1 20 ml of latex containing the polyglycidyl methacrylate particles obtained according to Cs. No. 225010 is mixed with 0.5 g of sodium sulfide monohydrate and stirred at 25 ° C for 12 hours. After the reaction is completed, it is dialyzed against running water until the odor has disappeared. The dry substance contains about 2% by weight. sulfur, which corresponds to the derivatization of about every 10th epoxy group. Example 2 20 ml of latex particles prepared by copolymerization of glycidyl acrylate with isoprene 15 to 85 ° / ohm. This is mixed with 0.5 g of potassium sulfide and stirred at 95 ° C for 30 minutes under an inert atmosphere. After removal of unreacted sulfide and drying, the product contains 0.06 wt. open. Example 3 20 ml of latex containing glycidylvinyletherstyrene copolymer particles 1: 99 wt. The amount of sulfur is unidentifiable elementally, but the particles are capable of reacting with dipyridyldisulfide and then activated with 1 gG. Example 4 20 ml of latex containing glycidyl methacrylate-vinyl acetate (85 to 15 wt%) copolymer particles were bubbled with hydrogen sulphide gas at 45 ° C for 48 hours, after separation the polymer contained approximately 1.2 wt% sulfur. INVENTION It -CH ₂ - CR ¹ - I AND X - CH ₂ -CH (CH ₂ OHJ- -SH wherein R ¹ is hydrogen or methyl and X is -O- or -CO-O-, or a mixture of polymerized units of formula I and 1-99 wt.% Of units formed by polymerizing monomers selected from the group consisting of glycidyl acrylate or methacrylate, alkyl acrylates or hydroxyalkyl acrylates or methacrylates, acrylamides or methacrylamides, styrene, divinylbenzene, N-vinylpyrrolidone, vinyl acetate, butadiene, isoprene and glycidyl vinyl ether. 2. A process for the preparation of hydrophilic latex particles containing thiol groups, which comprises latex particles consisting of a homopolymer of glycidyl acrylate, glycidyl methacrylate or glycidyl vinyl ether or copolymers thereof with 1-99% by weight. monomers selected from the group consisting of alkyl or hydroxyalkyl acrylates or methacrylates, acrylamides or methacrylamides, styrene, divinylbenzene, N-vinylpyrrolidone, vinyl acetate, butadiene and isoprene are reacted with hydrogen sulfide or alkali metal sulfide at temperatures up to 100 ° C.