Statistical evaluation of biocompatibility and biodegradability of chitosan/gelatin hydrogels for wound-dressing applications

This work aims to statistically assess the biocompatibility and the biodegradability of hydrogels which synthesized to different conditions for the wound-dressing applications. The present work also focuses on providing information about the synthesis of chitosan and gelatine by using a cross-linker. Experiments were designed by using Box-Behnken experimental design method. Effects of chitosan amount, gelatin amount and glutaraldehyde amount on biocompatibility and biodegradability of hydrogels have been statistically investigated. This parameters optimized by the response surface methodology in order to maximize responses as swelling, porosity, in vitro degradation and in vitro enzymatic degradation. Structural analysis of hydrogels was performed by FTIR spectroscopy. Analysis of variance was performed to assess statistically significant differences between the parameters on the biocompatibility and the biodegradability of hydrogels by using the Design Expert 13 statistical program. Mathematical model was found for each response variable, and the optimum values of the parameters were determined. The maximum percentage swelling, porosity, in vitro degradation and in vitro enzymatic degradation were obtained 470%, 92%, 83% and 86%, respectively, under conditions that 0.2 g chitosan, 0.8 g gelatin and 0.5 mL cross-linker. The limitations due to the use of glutaraldehyde are related to its high cytotoxicity. 1-(3-Dimethylaminopropyl)-3-ethyl-carbodimide (EDC) does not form toxic aldehydes. Therefore, EDC was used in hydrogel synthesis in our study for comparison against glutaraldehyde. In this optimum conditions, the effect of the molecular weight of chitosan, cross-linker type (glutaraldehyde and EDC) and ambient pH on biocompatibility (swelling, porosity analysis) and biodegradability was determined. In this study, to improve wound healing, it is thought that the results of the statistical evaluation of the effect of the simultaneous changes of the parameters on the properties of the biomaterial in obtaining the optimum condition hydrogels will contribute to biomedical applications.