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 µm. 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 µM) 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.

Evaluation of debridement effects of bromelain-loaded sodium alginate nanoparticles incorporated into chitosan hydrogel in animal models.

OBJECTIVES: Bromelain, a mixture of proteolytic enzymes from pineapple (Ananas comosus) is known as a potential debriding agent in burn treatment. In this research, the debridement efficiency of chitosan hydrogel loaded by sodium alginate-chitosan nanoparticles (NPs) containing bromelain (Br 10%-AG-CS NPs) was evaluated in animal models. MATERIALS AND METHODS: The NPs were prepared using the ionic gelation technique and their properties were identified. Then, the debridement effect of bromelain NPs incorporated into chitosan hydrogel was evaluated 4 hr after wound treatment in animal models. RESULTS: The particle size of positively charged Br-AG-Cs NPs was about 390±25 nm. The encapsulation efficiency of bromelain into AG-CS NPs was about 92%. The in vitro release profile showed that the maximum release of bromelain from NPs occurred during the first 4 hr (70%). The hydrogel structure did not significantly affect the profile release of bromelain in the formulation. After 6 months of storage at 4 and 25 °C, the synthesized NPs indicated no significant changes in bromelain activity. It was found that Br 10%-Ag-Cs NPs-CS hydrogel had the most beneficial effects on reducing necrotic tissues and resulted in re-epithelialization compared with other treated groups (negative and positive control, CS hydrogel, and Br 10%-CS hydrogel). CONCLUSION: Therefore, using this novel formulation can be considered a potential debridement agent.