Emulsified Chitosan-plga Scaffolds for Tissue Engineering

Abstract

This study evaluated the formation of chitosan-50:50 poly-lactic-co-glycolic acid (PLGA) blend matrices using controlled rate freezing and lyophilization technique. An emulsion system was used in the presence of 1,2-Dimyristoyl-sn-Glycero-3-Phosphocholine (DMPC), a cellular component, as a stabilizer. Blended scaffolds showed an open pore morphology and homogenous inter-dispersion of PLGA and chitosan. Forming emulsions after dissolving PLGA in chloroform, benzene, or methylene chloride indicated better emulsion stability with benzene and chloroform. Scaffolds formed by freezing at -20C, -78C and -196C from these emulsions showed significant influence of the solvent and freezing temperature on the microarchitecture of the scaffold. By controlling the concentration of chitosan, scaffolds with greater than 90% porosity were attained. Since the two polymers degrade by different mechanisms, formed scaffolds were analyzed for degradation characteristics for four weeks in presence of 10 mg/L lysozyme. The degradation results showed that chitosan scaffolds containing PLGA have an enhanced lysozymal degradation rate. This effect can be attributed to the acidic environment created by release of lactic and glycolic acids during the degradation of PLGA. When cellular activity of GFP-transfected smooth muscle cells were analyzed, no apparent cytotoxicity was observed. However, the cell spreading area decreased. In summary, these results show promising potential in tissue engineering.