Genipin-crosslinked chitosan hydrogels as biomedical and pharmaceutical aids

Genipin, a crystalline and well defined chemical compound, is extracted from gardenia fruits according to a modern microbiological process. As a water-soluble bi-functional crosslinking reagent, it reacts promptly with chitosan (and with proteins or amines in general) thus producing blue-coloured fluorescent hydrogels. The reaction mechanism between chitosan and genipin is well understood for a variety of experimental conditions. The resulting crosslinked complexes are not cytotoxic for the animal and human cells so far examined. The safety and the beneficial actions of genipin emerge from a number of research projects in the areas of the therapies of diabetes, periodontitis, cataract, hepatic dysfunction, as well as in wound repair and nerve regeneration. Food sciences, forensic chemistry and cytology have also provided evidence of the safety of its use. The most important applications of genipin in conjunction with chitosan are the preparation of elastic and resistant gels such as the cartilage substitutes, the manufacture of drug carriers for controlled release, the encapsulation of biological products and living cells, and the medication of wounds in animals and humans. Genipin might replace glutaraldehyde with the advantages of stability and biocompatibility of the crosslinked products whose quality assessment and manipulation would be easier.