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The objective of this study was to develop a collagen/hydroxyapatite (HA) nanocomposite scaffold for bone tissue engineering applications. For this purpose, in situ mineralization of HA was accompanied with formation of collagen hydrogel at condition similar to the physiological condition, pH = 7.4, and 37°C. The physicochemical and biological properties of the in situ scaffold were compared with nanocomposite fabricated by mixing HA powder and collagen hydrogel (powder-mixed scaffold). The HA in this method was formed in the same condition as the in situ method. X-ray diffraction and FTIR analysis of in situ scaffold showed the formation of carbonated HA, similar to bone, while the HA powder in powder-mixed scaffold showed non-carbonated structure. Scanning electron microscopy revealed the formation of fibrillated collagen in both composites. HA was observed in both scaffolds, but with different morphology. The in situ formed HA had a plate-like morphology while the preformed HA showed spherical morphology in the powder-mixed scaffold. The in-vitro cytocompatibility and osteogenesis activity of scaffolds using osteoblast-like cells (MG-63) showed higher cytocompatibility and more osteogenesis capability of the in situ scaffold in comparison with the powder-mixed scaffold. The results suggest the in situ method as a proper approach for fabrication of HA/collagen scaffolds with similar properties like bone. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 107B: 1920-1929, 2019., (© 2018 Wiley Periodicals, Inc.)

Extracellular matrix (ECM) components play a critical role in regulating cell behaviors. Interactions between ECM components and cells are important in various biological processes, including cell attachment, survival, morphogenesis, spreading, proliferation, and gene expression. In this study the in vitro responses of human induced pluripotent stem cells (hiPSCs) on polycaprolactone (PCL) electrospun nanofibrous scaffold were reported in comparison with those of the cells on corresponding solution-cast film scaffold. Our results demonstrated that the nanofibrous scaffold showed better support for the attachment and proliferation of hiPSCs than their corresponding film scaffold. Consequently, we emphasize that hiPSCs can sense the physical properties and chemical composition of the materials and regulate their behaviors accordingly., (© 2015 Wiley Periodicals, Inc.)

A very important obstacle in axonal regeneration after spinal cord injury is astroglial scaring. Noggin as bone morphogenic protein inhibitor plays a critical role in decreasing GFAP(+) cells and reducing the number of astrocytes in the site of injury. Human endometrial-derived stromal cells (hEnSCs) were isolated and cultured in two different neural inductive mediums consisting of neural progenitor maintenance medium (NPMM)/BDNF or NPMM/BDNF/Noggin in Matrigel 3D cell culture. Neural expression markers were investigated at the mRNA and protein level by real-time PCR and immunocytochemistry, respectively. The results showed that Noggin supplementation was able to increase the expression of Nestin, Tuj-1, and NF, whereas the expressions of GFAP, Bcl2, and Olig2 were decreased. In addition, DAPI staining demonstrated that lighter blue chromatin agreed with our observation of lower level of Bcl2 expression in the Noggin protocol in which over-expression of Bcl2 gene did not induce higher neurogenesis in poor Noggin medium. Our findings clearly demonstrated the neural differentiation potential of hEnSC in Matrigel and also Noggin supplementation was able to inhibit astrocyte formation., (© 2014 Wiley Periodicals, Inc.)

Spinal cord injury (SCI) in humans remains a devastating and incurable disorder. The use of Matrigel, a hydrogel-mimicking extracellular matrix, has been suggested as a scaffold for spinal cord regeneration. Human endometrial-derived stromal cells (hEnSCs) are abundant and available in adult stem cells with low immunological incompatibility, which could be considered for cell replacement therapy. The purpose of this study was to investigate the role of Matrigel in neural differentiation of hEnSCs in vitro and assess the supportive effects of this hydrogel in an animal model of SCI. hEnSCs were isolated and encapsulated into nanofibrous thermogel and cell viability and cell membrane damage were assessed. Encapsulated hEnSCs into Matrigel were treated with neural differentiation medium for 21 days, and then neural genes and protein markers were analyzed using real time-PCR and immunocytochemistry. Matrigel was implanted into rats with SCI and followed for 42 days using a behavioral test. Our study revealed a higher cell viability and neural differentiation in the level of genes and proteins as well as lower cell membrane damage. Substantial recoveries of motor function were observed in animals receiving the Matrigel treatment. The treatment with Matrigel, nanofibrous scaffold, produced beneficial effects on functional recovery following SCI in rats, possibly via assimilation to cytoskeleton fiber, high surface/volume ratio, spatial interconnectivity and containing some adhesive molecules and growth factors, enhancement of anti-inflammation, anti-astrogliosis, neuronal extension, and neuronal regeneration effects., (© 2014 Wiley Periodicals, Inc.)