Control of degradation rate and hydrophilicity in electrospun non-woven poly(D,L-lactide) nanofiber scaffolds for biomedical applications

Typical properties of poly(D,L-lactide) (PLA)-based scaffolds (films and foams), such as long degradation time, mechanical stiffness and hydrophobicity, are sometimes not suitable for biomedical applications. These properties can be substantially altered by electrospinning of PLA blends with miscible poly(lactide-co-glycolide) (PLGA) random copolymers, poly(lactide-b-ethylene glycol-b-lactide) (PLA-b-PEG-b-PLA) triblock copolymers, and a lactide (used as a hydrolytic catalyst). Electrospun scaffolds based on the multi-component PLA blends, comprised of randomly interconnected webs of sub-micron sized fibers, have a bulk density of 0.3-0.4g/cm³. In this study, the concentration effects of PLA-b-PEG-b-PLA triblock copolymer and lactide on the cell proliferation and the hydrophilicity of electrospun scaffolds were investigated. Based on in vitro degradation study, we found that the electrospun scaffold having PLA (40wt%), PLGA (LA/GA=50/50, 25wt%), PLA-b-PEG-b-PLA (20wt%), and lactide (15wt%) underwent a rapid weight loss of ∼65% in 7 weeks. The hydrophobicity of this membrane, as determined by contact angle measurements in a cell buffer solution, decreased by ∼50% from 105° (of an electrospun PLA scaffold) to 50°. The selection of suitable chemical compositions in conjunction with the non-invasive electrospinning process is useful in the production of a new kind of biodegradable scaffolds suitable for different biomedical applications such as cell storage and delivery as well as prevention of post-surgical adhesion because of their porosity, mechanical flexibility and tunable biodegradability.