Repair or replacement of damaged tissues using tissue engineering technology is considered to be a fine solution for enhanced treatment of different diseases such as skin diseases. Although the nanofibers made of synthetic degradable polymers, such as polylactic acid (PLA), have been widely used in the medical field, they do not favour cellular adhesion and proliferation. To enhance cell adherence on scaffold and improve biocompatibility, the surface of PLA scaffold was modified by gelatin in our experiments. For electrospinning, PLA and gelatin were dissolved in hexafluoroisopropanol (HFIP) solvent at varying compositions (PLA:gelatin at 3:7 and 7:3). The properties of the blending nanofiber scaffold were investigated by Fourier transform infrared (FT-IR) spectroscopy and scanning electron microscopy (SEM). Modified PLA/gelatin 7/3 scaffold is more suitable for fibroblasts attachment and viability than the PLA or gelatin nanofiber alone. Thus fibroblast cultured on PLA/gelatin scaffold could be an alternative way to improve skin wound healing.

Human-induced pluripotent stem cells (hiPSCs) are considered to be potentially able to differentiate into all human cell lineages and thus hold promise as an unlimited source for cell replacement therapies in clinical applications. Definitive endoderm (DE) formation is the first and crucial step in the development of visceral organs such as liver, lung, pancreas and so forth. Therefore, efficient generation of DE cells ensures the efficient generation of eventual target cells used in cell therapy. In the present study, Matrigel-coated poly(lactic acid)/gelatin (PLA/gelatin) nanofibrous scaffolds were utilized to investigate the proliferation and differentiation of hiPSCs into DE cells. Analyses of DE-specific markers including Sox17, FoxA2, and Gooscoid (Gsc) genes revealed higher levels of mRNA and protein expression in the differentiated hiPSCs cells cultured on PLA/gelatin scaffolds than cells differentiated in two-dimensional (2D) culture. Our results showed that three-dimensional (3D) cultures could significantly promote DE differentiation in comparison with 2D culture. Also using small molecules such as inducer of definitive endoderm 1 (IDE1) and signaling molecules such as Activin A and Wnt3a could enhance the DE differentiation of hiPSCs with Activin A/Wnt3a being significantly more potent in both 2D and 3D cultures compared to IDE1. The results of this study may have impact in tissue engineering and cell replacement therapy of visceral organs-related diseases.

Bone matrix consists of two major phases at the nanoscale: organic and hydroxyapatite. Nanotechnology as a diverse and interdisciplinary area of research has the capacity to revolutionise many areas of applications such as bone tissue engineering. Nanohydroxyapatite/gelatin composite has higher osteoblast attachment and proliferation than micro-sized ones, and shorter culturing period and lower cell seeding density compared to pure gelatin. A nanostructured scaffold was fabricated by three methods for bone repair using nanohydroxyapatite and gelatin as the main components. Its biocompatibility, alizarin red test on the 14th and 21st days, gene expression on the 21st day in in vitro using and histomorphometry after 4 and 8 weeks post-implantation in the rat were investigated. Cultured unrestricted somatic stem cells used for in vitro study showed an excellent level of cell attachment to the scaffold. Cells induced more osteoblast differentiation on the scaffold than in 2D cell culture. Osteoblast differentiation and bone regeneration results of in vitro and in vivo investigation on scaffold were extremely significant, better than control and treatment groups. These effects could be attributed to the shape and size of nanoHA particles and good architecture of the scaffold. The results confirm the feasibility of bone regeneration using synthesised scaffold as a temporary bone substitute.

Background Since women pay more attention to their skin's health, pharmaceutical companies invest heavily on skin care product development. Further, the success of drug nano-carriers in passing through the skin justifies the need to conduct studies at the nano-scale. β1-integrin down regulation has been proposed as a sign of skin aging. Methods Six drug nano-carriers (50 and 75 nm) were prepared at three ethanol concentrations (0, 3,and 5%) and different temperatures. Then, the impact of Nanocarriers on fibroblasts were investigated. Results DLS showed that increasing ethanol concentration decreased the surface tension that caused a decrease in the particle size in non-temperature formulations while increasing the temperature to 60°C to lower Gibbs free energy increased the particle size. Ethanol addition decreased β1-integrin over-expression, whereas larger nano-carriers induced an over-expression of β1-integrin, Bcl2/ Bax ratio, and an increase in live cell number. β1-integrin over-expression did not correlate with the rate of fibroblast proliferation and NFκB expression. An increase in fibroblast mortality in relation to smaller nano-carriers was not only due to the increase in Bax ratio, but was related to NFκB over-expression. Conclusion The development of a regenerative pharmaceutical approach in skin repair was based on the effect of particle size and ethanol concentration of the drug nano-carriers on the expression of β1-integrin in fibroblasts. A curcumin nanoformulation sized 77 nm and containing of 3% ethanol was more effective in increasing β1-integrin gene over-expression, anti-apoptosis of fibroblast cells (Bcl2/Bax ratio), and in decreasing Bax and NFκB gene expression than that with a particle size of 50 nm. Such a formulation may be considered a valuable candidate in anti-aging and wound-healing formulations.

Astroglial scaring and limited neurogenesis are two problematic issues in recovery of spinal cord injury (SCI). In the meantime, it seems that mechanical manipulations of scaffold to inhibit astroglial scarring and improve neurogenesis is worthy of value. In the present investigation, the effect of nanofiber (gel) concentration as a mechanical-stimuli in neurogenesis was investigated. Cell viability, membrane damage, and neural differentiation derived from endometrial stem cells encapsulated into self-assembling peptide nanofiber containing long motif of laminin were assessed. Then, two of their concentrations that had no significant difference of neural differentiation potential were selected for motor neuron investigation in SCI model of rat. MTT assay data showed that nanofibers at the concentrations of 0.125 and 0.25 % w/v induced higher and less cell viability than others, respectively, while cell viability derived from higher concentrations of 0.25 % w/v had ascending trend. Gene expression results showed that noggin along with laminin motif over-expressed TH gene and the absence of noggin or laminin motif did not in all concentrations. Bcl over-expression is concomitant with the decrease of nanofiber stiffness, NF cells increment, and astrogenesis inhibition and dark neuron decrement in SCI model. It seems that stiffness affects on Bcl gene expression and may through β-Catenin/Wnt signaling pathway and BMP-4 inhibition decreases astrogenesis and improves neurogenesis. However, stiffness had a significant effect on upregulation of GFAP cells and motor neuron recovery in in vivo. It might be concluded that eventually there is a critical definitive point concentration that at less or higher than of it changes cell behavior and neural differentiation through different molecular pathways.