Fabrication of Functionally Graded Electrospun Membranes Based on Silk Fibroin for Using as Dental Barrier Membranes in Guided Bone Regeneration

The guided bone regeneration (GBR) technique has been extensively used to preserve or regenerate the alveolar ridge by a membrane. This work aimed to design a functionally graded membrane (FGM) based on Bombyx mori silk fibroin (SF) natural protein with excellent handling and flexibility using electrospinning technique. This FGM membrane consists of two practical layers, one layer for preventing gingival fibroblast ingrowth and the other for supporting osteogenic cell growth, used in the guided bone regeneration (GBR) technique. Both layers were fabricated through the electrospinning technique with different collector speeds (800 & 2000 rpm). Soaking in glycerol and mechanical cold pressing was utilized to mitigate the brittleness of electrospun mats and enhance their tensile strength, respectively. The biodegradation rate was studied in vitro through soaking in artificial saliva. The mechanical properties of fabricated samples were measured using a micro tensile test machine. In addition, the viability of cells was evaluated via MTT and cell attachment assays. A field emission scanning electron microscope (FESEM) was also utilized for morphological observations in different steps of production. The biodegradation rate showed negligible mass loss after 4 weeks. The maximum tensile strength of functionally graded membranes (FGM) was obtained around 9 MPa in dry state. Microstructural evaluation of samples revealed beadles structure and acceptable adhesion and growth of fibroblast cells on them. The viability of cells using MTT assay was revealed no cytotoxic effects. The results of different characterizations show promising potential of produced FGM samples for application as dental barrier membranes in guided bone regeneration.