A novel spatially designed and functionally graded electrospun membrane for periodontal regeneration.

A periodontal membrane with a graded structure allows tailoring of the layer properties to design a material system that will retain its physical, chemical and mechanical characteristics for a period long enough to optimize periodontal regeneration. In this work a novel functionally graded membrane (FGM) was designed and fabricated via sequential multilayer electrospinning. The FGM consists of a core layer (CL) and two functional surface layers (SLs) interfacing with bone (nano-hydroxyapatite, n-HAp) and epithelial (metronidazole, MET) tissues. The CL comprises a neat poly(DL-lactide-co-ε-caprolactone) (PLCL) layer surrounded by two composite layers composed of a protein/polymer ternary blend (PLCL:PLA:GEL). Electrospinning parameters involved in fabrication of the individual layers (i.e. neat PLCL, ternary blend, PLA:GEL+10%n-HAp and PLA:GEL+25%MET) were optimized to obtain fibrous layers free of beads. Morphology, structure and mechanical property studies were carried out on each electrospun layer. The individual fiber morphology and roughness of the functional SLs, which are the n-HAp containing and drug-incorporating layers were evaluated by atomic force microscopy. The CL structure demonstrated higher strength (8.7 MPa) and a more elastic behavior (strain at break 357%) compared with the FGM (3.5 MPa, 297%). Incorporation of n-HAp to enhance osteoconductive behavior and MET to combat periodontal pathogens led to a novel FGM that holds promise at solving the drawbacks of currently available membranes.