A Novel Scaffold for the Construction of Polyelectrolyte Thin Films for Non-Viral Gene Delivery

The avian egg shell membrane (ESM) is an abundant and environmentally friendly complex of two semi-permeable membranes, which are composed of highly cross-linked extra-cellular proteins. The ESM has been shown to be biocompatible and a potential biomaterial in tissue engineering applications. We have utilized ESM as scaffold for the delivery of non-viral vectors deposited within polyelectrolyte multilayer (PEM) thin films constructed by the alternating deposition of hydrolytically degradable polycations (poly â-amino ester) and polyanions (plasmid DNA vectors). These ESM-PEM gene delivery devices progressively released the plasmid DNA sequentially deposited on the 3-D fibrous scaffold. The PEM-modified surfaces of the ESM were able to support the adhesion, proliferation and differentiation of MC3T3-E1 pre-osteoblast cells. The engrafted MC3T3-E1 cells were distributed throughout the full-thickness of the ESM and expressed the genes encoded in the plasmid DNA vectors. The increased surface-to-volume ration of the ESM and its relative ease of handling may make ESM a highly versatile 3-D scaffold for tissue engineering applications, such as bone fracture healing.