Pectin/poly(lactide-co-glycolide) composite matrices for biomedical applications.

The aim of the research was to develop matrices for the delivery of biologically active substances for tissue regeneration. To this end, a new biodegradable matrix composed of a hydrophobic porous poly(lactide-co-glycolide), p(LGA), network entangled with another network of hydrophilic pectin was fabricated in the presence of calcium chloride. The calcium salts function as both a pore forming reagent and cross-linker for the formation of pectin networks; the method combines creating pores and cross-linking polymers in one step. Microscopic imaging and dynamic mechanical analysis revealed a double-network structure of the composite matrices. The pectin enables the composite to carry signal molecules. This is accomplished by linking signal molecules to pectin by physical adsorption or by chemical reaction. The p(LGA) networks in the composite impart mechanical properties comparable to p(LGA) alone. The mechanical properties of the composite are far superior to matrices containing only pectin. Furthermore, the pectin-containing matrices improved cell adhesion and proliferation when compared to plain p(LGA) matrices, as determined in vitro by osteoblast culture.