Evaluation of the osteogenic potential of crocin-incorporated collagen scaffold on the bone marrow mesenchymal stem cells

Objective The present study aimed to evaluate the effect of crocin (CRO)-loaded collagen (COL) scaffold on the osteogenic differentiation of rat bone marrow-derived mesenchymal stem cells (BM-MSCs). Significance Different studies have been conducted to develop an efficient strategy to accelerate and improve the recovery process of bone defects. It was shown that CRO, extracted from saffron, could induce osteogenic differentiation of rat BM-MSCs. Scaffolds can also provide a three-dimensional environment for migration, adhesion, growth, and proliferation of MSCs. Methods Collagen scaffolds were fabricated through freeze-drying followed by cross-linking by dehydrothermal method. Then, CRO was incorporated into the scaffolds. Physicochemical characterization of the scaffolds was evaluated. Rat BM-MSCs were seeded on CRO-loaded COL scaffolds and cultured for 14 days. Osteogenic differentiation was evaluated using alizarin red (ALZ) staining and alkaline phosphatase (ALP) activity assay and compared to the positive control group. Results The average pore size of the COL scaffolds was about 97 +/- 6.7 mu m. Formation of amide cross-links was confirmed by FTIR. The scaffolds were capable of uptaking water up to 50 times more than their initial dry weight and releasing above 90% of their uploaded CRO during 24 h. Collagen scaffolds containing CRO (25 and 50 mu M) increased ALZ intensity (3.16 +/- 0.3 and 7.32 +/- 0.3 folds, respectively) and ALP activity (13.7 +/- 1.1 and 12.2 +/- 9.4 folds, respectively) in comparison with the positive control group. Conclusion Crocin-loaded COL scaffold could effectively enhance calcium deposition and ALP activity in BM-MSCs and therefore proposed as a good candidate to accelerate the healing process of vital bone defects.