Polymeric biomaterials which contain thiol/disulfide bonds with a variety of good characteristics have the strong potential to be used as release carriers for drugs and genes. With the development of genetic engineering and tissue engineering, biodegradability of these materials has drawn much more attention of researchers and become the key factor limiting their applications as biomaterials. Disulfide bond remains stable in the extracellular environment while broken in the cytosolic reducing environment. In terms with this property, it is frequently used in the preparation of the carrier materials for the drug and gene delivery systems. The introduction of disulfide bonds to the materials provides an effective way to design or improve the biodegradability. In this review, we focused on the research progress and test methods of the thiol/ene photopolymerization reaction, Michael addition reaction and the redox reaction taking the hydrogels, polymer micells and vesicles as the typical examples. Different methods about the formation of thiol/ene disulfide bonds in the polymer were also presented. And the preparation and surface modification of three kinds of reduction-sensitive materials, including gene carriers, drug delivery vectors and small molecule drug carriers, were discussed in detail. The importance of the research on the polymeric biomaterials which contains thiol/disulfide bonds in the field of biomedical applications has been further emphasized. Contents
1 Introduction
2 Photopolymerization polymers
3 Michael addition polymers
4 Reduction-sensitive polymers
4.1 Gene carriers
4.2 Protein vectors
4.3 Small molecule drug carriers
5 Prospects