Evaluating the effect of cryopreservation, cell migration and perfused media on degradation of porous scaffold

The degradation of scaffolds is a critical aspect in tissue engineering and regenerative medicine. Various factors that influence the degradation of scaffold are viscosity, density, hydrophilicity, temperature, cells and degradation environment. In present study, the degradation of scaffold were evaluated in presence of perfused media, Red blood cells (RBC), and cryogenic conditions. Different properties such as density, viscosity and contact angle of bio-ink used for fabrication of scaffold were also evaluated and their correlation to desired environment conditions were also evaluated. A poly electrolyte complex scaffolds (chitosan: alginate, chitosan: gelatine), and explicit scaffolds were considered for degradation study. Explicit scaffold and PEC scaffolds were fabricated form chitosan, alginate and gelatine at mixing ratio of 20:80, 50:50, and 80:20 concentration by solvent casting and etching method. The scaffold degradation studies in perfused media were performed at flow rate of 0.5 ml/min, 1 ml/min and 2 ml/min. The parameters related to degradation of scaffold such as weight and pH of discharge media were also evaluated. Results indicated that degradation of chitosan: alginate at 20:80 concentration had shown maximum degradation in presence of RBCs. Similarly, degradation pattern was equal to linear patten for all the scaffolds except 20:80 and 50:50 concentration of chitosan-alginate in cryogenic conditions. Result of scaffolds degradation in perfused media had shown that scaffolds were degraded maximal at a flow rate of 1 ml/min as compare to other flow rates. Contact angle measurement had proved that all PEC scaffold belongs to the category of hydrophilic family. The scaffold fabricated from higher concentration of chitosan had revealed slower degradation as compare to others configuration. The acceleration of scaffold degradation was tiggered by enzymatic and cellular activities in the presence of RBCs. Perfused media had caused scaffold degradation due to presence of mechanical shear stress.

Graphical abstract