Chitosan is formed by chitin deacetylation and consists of -(1-4)-linked d-glucosamine and N-acetyl-d-glucosamine. Since this polycationic polysaccharide contains glucosamine and N-acetylglucosamine molecules, chitosan has a high degree of structural similarity to natural glycosaminoglycans (GAG). Chitosan bioink has been investigated for various tissue engineering applications and drug delivery in recent years due to its high biocompatibility and biodegradability, low immunogenicity and cationic nature. In addition, because of its unique hemostatic and anti-infective activity, chitosan bioink is regarded as wound healing promoter and widely employed in wound healing application.
However, unmodified chitosan can dissolve in acidic solutions due to strong intermolecular hydrogen bonds; this limits its use as an injectable hydrogel. Chitosan is functionalized with methacrylic anhydride so that the polymer can be photo crosslinked through chain-growth, step-growth, or a combination of both mechanisms referred to as mixed mode.
≥85% fibroblast cells, mesenchymal stem cells and osteoblast cells
Substitution degree of chitosan
Chitosan methacrylate bioinks developed by AdBioInk Biosystem Corp. are prepared by using two different photoinitiators, Irgacure2959 and LAP. Cell adhesion and cell encapsulation experiments were performed against NIH-3T3 cell line. The cells successfully adhere onto the Chitosan bioinks, proliferate and are able to preserve their cell morphology. According to Live/Dead staining results in which cell viability was examined, it was observed that cell viability was over 90% for 7 days and encapsulated cells preserved their viability. Chitosan bioinks, in which the cell morphologies of the encapsulated hydrogels were examined, showed that the cells formed their cytoplasmic protrusions and started to acquire morphology on the 7th day with the soft structure.