Effect of wheat gluten on improved thermal cross-linking and osteogenesis of hydroxyapatite-gelatin composite scaffolds.

Promising strategies to stabilize gelatin or collagen include glutaraldehyde-based chemical cross-linking or dehydrothermal treatment at different temperatures (120-180 °C). However, these procedures require 24-48 h for complete cross-linking to occur. The present study aims to evaluate the role of wheat gluten on enhancing thermal cross-linking of silica-nanohydroxyapatite (nanoHA)-gelatin composite scaffolds within a shorter period (2 h). Changes in properties were evaluated by varying the ratio of gelatin and gluten in silica-nanoHA matrix (60 wt% ceramic: 40 wt% polymer). The results showed that the scaffolds cross-linked at 170 °C were stable in phosphate-buffered saline for 21 days. It was crystalline and porous in nature. However, the scaffolds with high weight percentage of wheat gluten were brittle, while those with low gluten degraded fast in vitro. The mesenchymal stem cells could adhere, proliferate and differentiate into osteogenic lineage on wheat gluten-containing scaffolds for 21 days (mainly medium concentration). The scaffold also supported new bone formation in critical-sized rat calvarial defect, showing its osteoconductive and osteointegrative nature. In short, this study showed the potential of wheat gluten on improving thermal cross-linking within a shorter period and its suitability to use as a biomimetic bone graft for bone tissue engineering.

Bioinspired nanocomposite fibrous scaffold mediated delivery of ONO-1301 and BMP2 enhance bone regeneration in critical sized defect.

Treatment aiming to enhance bone tissue regeneration can benefit from multiple growth factor or small molecule delivery. In the present study, the objective was to evaluate the feasibility of using nanocomposite fibrous scaffold to deliver prostacyclin I2 agonist ONO-1301 in combination with BMP2 for treating critical sized bone defect. For this, ONO-1301 at three different concentrations (1.67 µg, 5 µg, 15 µg) and a fixed dose of BMP2 (5 µg) was loaded on the scaffold via physical adsorption. The results showed fast release of ONO-1301 for two weeks, whereas BMP2 exhibited slow and sustained release for four weeks. The scaffold with dual factors promoted the migration and osteogenic differentiation of mesenchymal stem cells (MSCs) in vitro when compared to the scaffold with BMP2 alone. It also augmented bone tissue regeneration in critical sized rat calvarial defect at 12 weeks; mainly with lower dose of ONO-1301. However, synergistic effect on osteogenic differentiation and bone regeneration were not obtained through the concurrent release of BMP-2 and ONO-1301.