Branched/Hyperbranched Copolyesters from Poly(vinyl alcohol) and Citric Acid as Delivery Agents and Tissue Regeneration Scaffolds

Abstract

Multifunctional branched/hyperbranched copolymers from poly(vinyl alcohol) (PVA) and citric acid (CA) are synthesized by varying the mole compositions of PVA and CA and are used as a prospective vehicle for encapsulation and release of bioactive molecules and as a potential scaffold for cell adhesion and growth. The branched architecture is established from spectroscopy and rheological measurements. All the copolymers have shown a lower hydrodynamic size and viscosity than the linear, high molecular weight PVA because of spherical and more compact architecture. Importantly, the size of the highly branched copolymer is found independent of pH which proved that the branch ends are capped with OH groups. Lower viscosity at equivalent solid content, biocompatibility, high antibacterial property, and presence of adequate macromolecular voids make the branched/hyperbranched copolymers a potential platform for encapsulation and release of gentamicin and other bioactive molecules. The macromolecular voids and chain end functionality also promote adhesion and growth of differentiated primary cells as well as undifferentiated stem cells implying that the copolyester can also be used as a potential 2D/3D scaffold for tissue engineering applications.