Novel bone scaffold containing biomimetic peptide for bone tissue engineering

Abstract

Event Abstract Back to Event Novel bone scaffold containing biomimetic peptide for bone tissue engineering Samaneh Hosseini1, Mohamadreza Baghaban Eslaminejad1 and Shahab Faghihi2 1 Royan Institute for Stem Cell Biology and Technology, ACECR, Department of Stem Cells and Developmental Biology, Cell Science Research Center, Iran 2 National Institute of Genetic Engineering and Biotechnology, Tissue Engineering and Biomaterials Division, Iran The regeneration of diseased or fractured bone represents a premier clinical need, as numerous patients suffer from deficient healing of bone in variety of medical conditions like traumatic fracture, congenital malformation, and surgically bone defects. Tissue engineering emerges as a promising strategy to overcome limitations of traditional bone grafts such as donor site morbidity and the absence of osteogenic properties [1]. Biomaterial design with biomimetic peptide which have biomineralization ability holds great potential for successful bone regeneration. Since the hydroxyapatite (HA) is the major inorganic component of bone, HA-binding ‎peptide could promote formation of mineral phase of bone and osteogenesis [2][3]. Our previous study showed that a natural motif sequence of osteocalcin (OSN) has ability to nucleate apatite nanocrystals[4]. The objective of this study is to develop a collagen-chitosan nanoparticle containing biomineralizing peptide scaffold for directing the osteogenic differentiation of adipose derived stem cells (AD-MSCs). Toward this goal, osteocalcin mimetic peptide (OSN) was constructed by stepwise solid-phase synthesis manually. The peptide was purified by reverse-phase HPLC and was checked for ‎homogeneity by analytical RP-HPLC which indicated a purity> 95%. Molecular weights was ‎confirmed by MALDI-TOF mass ‎spectra.‎ Peptide-chitosan nanoparticles were prepared by physical self-assembly method. Surface charge and mean particle ‎size of peptide and peptide-nanoparticles were determined by ‎‎nanozetasizer. OSN-chitosan nanoparticles were networked with collagen to provide multifunctional and structurally stable biomatrix, following were analyzed using scanning electron microscopy (SEM). Adipose derived stem cells were isolated from the fat tissue of 6 weeks Wistar rats and were then characterized for osteoblast, adipocyte and chondrocytes differentiations. ‎‎‎‎The ‎cellular response of AD-MSCs on proliferation and viability is ‎examined using MTT assay. Mineralization of extracellular ‎matrix and accumulation of calcium was also assessed using Alizarin red-S staining and calcium ‎assay. Evaluation of constructed scaffold revealed the optimum structural properties. MTT results confirmed that not only is there no evidence of cytotoxicity related to OSN but also the cells which are cultured on OSN containing sample had ‎significant increase in proliferation rate in comparison with control (Fig. 1). Calcium content analysis indicated that there was a 2-fold increase in the amount of calcium in the presence of OSN compared ‎to control. According to alizarin S staining, the number of mineralized nodules was increased in samples containing ‎OSN compared with control (Fig. 2). Altogether, it is believed that the construct containing OSN is able to induce bone formation by increasing mineralization. This ‎study has significant implication for tissue engineering and osteocalcin mimetic peptide may have great utility in future bone clinical applications as a bioactive inducer of biomineralization for bone regeneration.