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Treating critical-sized bone defects is an important issue in the field of tissue engineering and bone regeneration. From the various biomaterials for bone regeneration, collagen is an important and widely used biomaterial in biomedical applications, hence, it has numerous attractive properties including biocompatibility, hyper elastic behavior, prominent mechanical properties, support cell adhesion, proliferation, and biodegradability. In the present study, collagen was extracted from duck's feet (DC) as a new collagen source and combined with quercetin (Qtn), a type of flavonoids found in apple and onions and has been reported to affect the bone metabolism, for increasing osteogenic differentiation. Further, improving osteoconductive properties of the scaffold hydroxyapatite (HAp) a biodegradable material was used. We prepared 0, 25, 50, and 100 μM Qtn/DC/HAp sponges using Qtn, DC, and HAp. Their physiochemical characteristics were evaluated using scanning electron microscopy, compressive strength, porosity, and Fourier transform infrared spectroscopy. To assess the effect of Qtn on osteogenic differentiation, we cultured bone marrow mesenchymal stem cells on the sponges and evaluated by alkaline phosphatase, 3-4-2, 5-diphenyl tetrazolium bromide assay, and real-time polymerase chain reaction. Additionally, they were studied implanting in rat, analyzed through Micro-CT and histological staining. From our in vitro and in vivo results, we found that Qtn has an effect on bone regeneration. Among the different experimental groups, 25 μM Qtn/DC/HAp sponge was found to be highly increased in cell proliferation and osteogenic differentiation compared with other groups. Therefore, 25 μM Qtn/DC/HAp sponge can be used as an alternative biomaterial for bone regeneration in critical situations., (© 2019 Wiley Periodicals, Inc.)

Tissue engineered scaffolds, made of natural derived materials, have the potential to be used in bone regeneration fields due to the biocompatible and biodegradable features. In this study, we propose duck's feet-derived collagen (DC) sponges blended with hydroxyapatite (HAp), incorporated with different concentrations of silymarin (Smn), for improved bone regeneration. The morphological and structural properties of DC/HAp and DC/HAp loaded with 25, 50 and 100 μM of Smn sponges were analyzed using scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR). In vitro evaluations were carried out on rabbit bone marrow stem cells (rBMSCs) using MTT assay for cell proliferation, ALP assay for osteogenic differentiation and reverse transcription-polymerase chain reaction (RT-PCR) for expression of mRNAs. For the evaluation of new bone formation in vivo, histological analysis and micro computed tomography (μCT) were used. Preliminary results, on Smn/DC/HAp morphology and mechanical properties, showed an interconnected porosity suitable for cells ingrowth and a higher compressive strength with the presence of Smn. Similarly, the cells proliferation and ALP activity modulation were positively influenced by the Smn content. Especially, the 100 μM Smn/DC/HAp sponge efficiently enhances the rBMSCs adhesion, growth and gene expression of osteogenic markers. The enhanced osteoinductive effects of sponges blended with Smn were confirmed using μ-CT and histological evaluations. In conclusion, results suggest that collagen sponges represent an excellent environment for cells growth and proliferation, while Smn plays an important role to improve materials osteogenic properties., (Copyright © 2018 Elsevier B.V. All rights reserved.)

Scaffolds mimicking structural and chemical characteristics of the native bone tissues are critical for bone tissue engineering. Herein, we have developed and characterized epigallocatechin gallate/duck’s feet collagen/hydroxyapatite (EGCG/DC/HAp) composite sponges that enhanced the bone tissue regeneration. The three-dimensional composite sponges were synthesized by loading various amounts (i.e. 1, 5 and 10 μM) of EGCG to duck feet derived collagen followed by freeze-drying and then coating with hydroxyapatite. Several measuremental techniques were employed to examine the properties of the as-fabricated composite sponges including morphology and structure, porosity, compressive strength, etc. and as well compared with pristine duck feet derived collagen. SEM observations of EGCG/DC/HAp sponges showed the formation of a highly porous collagen matrix with EGCG embodiment. The porosity and pore size of sponges were found to increase by high EGCG content. The compressive strength was calculated as 3.54 ± 0.04, 3.63 ± 0.03, 3.89 ± 0.05, 4.047 ± 0.05 MPa for 1, 5 and 10 μM EGCG/DC/HAp sponges, respectively. Osteoblast-like cell (BMSCs isolated from rabbit) culture and in vivo experiments with EGCG/DC/HAp sponges implanted in nude mouse followed by histological staining showed enhanced cell internalization and attachment, cell proliferation, alkaline phosphatase expressions, indicating that EGCG/DC/HAp sponges have ahigh biocompatibility. Moreover, highEGCG content in the EGCG/DC/HAp sponges have led to increased cellular behavior. Collectively, the 5 μM of EGCG/DC/HAp sponges were suggested as the potential candidates for bone tissue regeneration. [ABSTRACT FROM AUTHOR]