Differential anti-inflammatory properties of chitosan-based cryogel scaffolds depending on chitosan/gelatin ratio

Chitosan/gelatine-based materials have been widely used as biocompatible scaffolds in the tissue engineering field. Chitosan suppresses the inflammatory activities of macrophages whereas gelatine induces inflammatory cytokine production by these cells. Cryogel form of the scaffolds created an effect that was mostly dominated by chitosan activity. Since independent of chitosan to gelatine ratio, the cryogels eliminated the inflammatory cytokine production by the activated macrophages. This will enable suppression of inflammatory reactions by macrophages during implant procedure while enabling a nest of the matrix for the macrophages to reside. Determining the immunomodulatory effect of these materials during the decay is crucial to assess their biocompatibility and safety. Our results suggest that when the chitosan ratio was higher than that of gelatine the materials had anti-inflammatory activity in their powder forms based on TNFα production levels by LPS activated macrophages, whereas higher gelatine to chitosan ratio eliminated this effect. To our knowledge, this is the first study to assess the powder vs. gel forms of the chitosan/gelatine-based materials for their immunomodulatory potentials as well as how the ratio of chitosan to gelatine might affect these materials immunomodulatory effects on the activated macrophages.HIGHLIGHTSChitosan/gelatin composite cryogels have anti-inflammatory activities.Different ratios of chitosan to gelatin content altered the immunomodulatory activities.They can be safely and effectively used as implant materials for tissue engineering applications.They will also reduce the use of anti-inflammatory drugs during implantation.