A judicious approach of exploiting polyurethane-urea based electrospun nanofibrous scaffold for stimulated bone tissue regeneration through functionally nobbled nanohydroxyapatite

Complete natural healing of skeletal tissues may take several months or even years, depending on the type and size of defects owing to slow auto-osteogenesis. Numerous techniques have been explored to gear-up the bonehealing process, as bone tissue has complex nanohybrid hierarchical meshwork containing nano apatite layers. Healing of such tissues associates with risks of pathogenic infection and ectopic bone formation. Therefore, most of the approaches fail to meet the requisite criteria to adopt in clinical practice. Carbonaceous bone substitutes may trigger healing, but an excess of it may render many adverse effects. In the current study, nanohydroxyapatite (nHA) was prepared, doped with a minute amount (0.15%) of carboxyl functionalized multiwall carbon nanotube (CCNT). The hybrid nanomaterial (CCNTH) was introduced within the synthesized biomolecule tethered segmented polyurethane-urea (SP) through in-situ technique and scaffolds were fabricated by electrospinning technique. CCNT doping improves the tensile strength and the hardness of the nano-scaffold by 94.5% and 173.6%, respectively. In vitro MTT assay, FESEM and protein adsorption study indicated the excellent cytocompatibility of the nanohybrid scaffolds. The qRT-PCR study indicates the significant expression of the osteogenic bone marker, osteocalcin (OCN) and the alkaline phosphatase (ALP) of the CCNTH incorporated nanohybrid scaffolds compared to the SP scaffold. Furthermore, the in vivo rat tibia and skull model exhibit excellent bone regeneration efficacy compared to the control without showing any sign of organ toxicity. Thus, a minute amount of CCNT doped nHA incorporated SP based micro-porous nanohybrid scaffold can be used as an alternate suitable biomaterial for osteoinduction application.