Modeling and optimization of gelatin-chitosan micro-carriers preparation for soft tissue engineering: Using Response Surface Methodology.

Electrospray ionization is a wide spread technique for producing polymeric microcarriers (MCs) by applying electrostatic force and ionic cross-linker, simultaneously. In this study, fabrication process of gelatin-chitosan MCs and its optimization using the Response Surface Methodology (RSM) is reported. Gelatin/chitosan (G/C) blend ratio, applied voltage and feeding flow rate, their individual and interaction effects on the diameter and mechanical strength of the MCs were investigated. The obtained models for diameter and mechanical strength of MCs have a quadratic relationship with G/C blend ratio, applied voltage and feeding flow rate. Using the desirability curve, optimized G/C blend ratios that are introduced, include the desirable quantities for MCs diameter and mechanical strength. MCs of the same desirable diameter (350μm) and different G/C blend ratio (1, 2, and 3) were fabricated and their elasticity was investigated via Atomic Force Microscopy (AFM). The biocompatibility of the MCs was evaluated using MTT assay. The results showed that human Umbilical Cord Mesenchymal Stem Cells (hUCMSCs) could attach and proliferate on fabricated MCs during 7days of culturing especially on those prepared with G/C blend ratios of 1 and 2. Such gelatin-chitosan MCs may be considered as a promising candidate for injectable tissue engineering scaffolds, supporting attachment and proliferation of hUCMSCs.