Design and Fabrication of Functional Scaffolds for Bone Regeneration Applications

Abstract

Bone tissue regeneration across critical sized segmental bone defects requires external intervention in order to enable tissue growth across the gap which would otherwise be non-regenerating. Such intervention commonly includes use of bone grafts which have inherent limitations. In this research, a synthetic scaffold device was fabricated using the polymer poly (vinyl alcohol) (PVA) and an attachment mechanism was designed for the device for use in long bone fractures. Electrospinning was used in order to fabricate scaffold with porosity at the micro scale which is an essential feature for cellular integration. The scaffolds were augmented with sheets fabricated using mold casting in order to enhance the mechanical strength of the device. The final device was fabricated with electrospun and casted specimen stacked in an alternating manner. A hollow, tubular sleeve was fabricated using polyurethane (PUR) and used for the attachment mechanism. The device was cut into the shape of a disc of 20 mm diameter and inserted into the polymeric sleeve. Specimen of the device having dimension 20 x 20 x 6 mm for length, width and height respectively were used for analysis using scanning electron microscope, universal testing machine and phosphate buffer saline for studying scaffold morphology, device strength and degradation rate respectively. The results showed that PVA electropsun mats had nanofiber diameter of 87.42 ± 38.53 nm and pore size of 0.5 μm. Mechanical strength of the device under compressive loading yielded compressive strength of 0.49 ± 0.07 MPa while degradation rate of the scaffold was 270 minutes. A 3-D scaffold was hence fabricated in this study that can enable both functional and mechanical properties to be achieved using two relatively simple fabrication techniques.