Silk fibroin/vitreous humor hydrogel scaffold modified by a carbodiimide crosslinker for wound healing.

Natural-derived biomaterials can be used as substrates for the growth, proliferation, and differentiation of cells. In this study, bovine vitreous humor as a biological material was cross-linked to silk fibroin with different concentration ratios to design a suitable substrate for corneal tissue regeneration. The cross-linked samples were evaluated with different analyses such as structural, physical (optical, swelling, and degradation), mechanical, and biological (viability, cell adhesion) assays. The results showed that all samples had excellent transparency, especially those with higher silk fibroin content. Increasing the ratio of vitreous humor to silk fibroin decreased mechanical strength and increased swelling and degradation, respectively. There was no significant difference in the toxicity of the samples, and with the increase in vitreous humor ratio, adhesion and cell proliferation increased. Generally, silk fibroin with vitreous humor can provide desirable characteristics as a transparent film for corneal wound healing.

A fabricated hydrogel of hyaluronic acid/curcumin shows super-activity to heal the bacterial infected wound.

High risk of acute morbidities and even mortality from expanding the antibiotics resistant infectious wounds force indefinite efforts for development of high performance wound-healing materials. Herein, we design a procedure to fabricate a hyaluronic acid (HA)-based hydrogel to conjugate curcumin (Gel-H.P.Cur). The highlight of this work is to provide a favorite condition for capturing curcumin while protecting its structure and intensifying its activities because of the synchronization with HA. Accordingly, HA as a major component of dermis with a critical role in establishing skin health, could fortify the wound healing property as well as antibacterial activity of the hydrogel. Gel-H.P.Cur showed antibacterial properties against Pseudomonas aeruginosa (P. aeruginosa), which were examined by bactericidal efficiency, disk diffusion, anti-biofilm, and pyocyanin production assays. The effects of Gel-H.P.Cur on the inhibition of quorum sensing (QS) regulatory genes that contribute to expanding bacteria in the injured place was also significant. In addition, Gel-H.P.Cur showed high potential to heal the cutaneous wounds on the mouse excisional wound model with repairing histopathological damages rapidly and without scar. Taken together, the results strongly support Gel-H.P.Cur as a multipotent biomaterial for medical applications regarding the treatment of chronic, infected, and dehiscent wounds.

Temperature-dependent formulation of a hydrogel based on Hyaluronic acid-polydimethylsiloxane for biomedical applications.

Hyaluronic acid (HA), as a safe biomaterial with minimal immunogenicity, is being employed in a broad range of medical applications. Since unmodified HA has a high potential for biodegradation in the physiological condition, herein, an HA-based cross-linked hydrogel was formulated using polydimethylsiloxane-diglycidyl ether terminated (PDMS-DG) via epoxide-OH reaction. The formation of HA-PDMS hydrogel was confirmed using FTIR, NMR, and FESEM. Temperature demonstrated a critical role in the physicochemical properties of the final products. Gel-37, which formed at 37 °C, had a higher modification degree (MD) and more stability against hyaluronidase and oxidative stress than the hydrogel formulated at 25 °C (Gel-25). In addition, the swelling ratio, roughness, and porous network topology of Gel-25 and Gel-37 were different. The rheology measurement indicated that HA-PDMS hydrogel had a stable viscoelastic character. The hydrogel was also biocompatible, non-cytotoxic, and considerably stable during 7-months storage. Overall, various determined parameters confirmed that HA-PDMS hydrogel is worth using in different medical applications. Keywords: Hyaluronic acid; Polydimethylsiloxane-diglycidyl ether terminated; Hydrogels; Long-term stability; Viscoelastic behavior; Biocompatibility.

Atrial and ventricular specification of ADSCs is stimulated by different doses of BMP4.

To investigate the effect of BMP4 on cardiomyocyte differentiation of adipose tissue-derived stem cells (ADSCs), mouse ADSCs were treated with different concentrations of BMP4 in media containing fetal bovine serum (FBS) or Knockout™ Serum Replacement (KoSR). 3 weeks after cardiac induction, differentiated ADSCs expressed some cardiac-specific genes and proteins. BMP4 treatment upregulated the expression of cardiac transcription factors. In both FBS and KoSR-supplemented media, lower concentrations of BMP4 had a positive effect on the expression of MLC2A gene, while MLC2V was more expressed with higher concentrations of BMP4. BMP4 treatment in KoSR supplemented medium was more efficient for cardiac induction. Supplementation of culture media with insulin-transferrin-selenium improved the expression of MLC2A gene. The results of this study indicated that BMP4 is important for cardiac differentiation of the ADSCs. However, BMP4 was not enough for structural and functional maturation of the ADSC-derived cardiomyocytes.

Oxytocin improves proliferation and neural differentiation of adipose tissue-derived stem cells.

The neurohypophyseal hormone oxytocin plays a role in stimulation of neurogenesis in the adult brain. However, the exact role of oxytocin in neural development is still not well understood. In the present study, we evaluated the effect of oxytocin on neural differentiation of mouse adipose tissue-derived stem cells (ADSCs). For this purpose, ADSCs were cultured in a medium containing Knockout™ Serum Replacement (KoSR) and treated with different concentrations of oxytocin at the first or eighth day of differentiation. Two weeks after neural induction, ADSCs expressed several early and late neuron-specific genes and proteins. MTT assay and cell cycle analysis revealed a stimulatory effect of oxytocin on viability and proliferation of differentiating ADSCs. As detected by quantitative real-time PCR, treatment of the ADSCs with low concentrations of oxytocin induced neurogenesis. Oxytocin treatment also upregulated the expression of oxytocin receptor mRNA. These results demonstrated for the first time that oxytocin treatment can promote neural differentiation of the ADSCs in a dose-dependent and time-dependent manner. Oxytocin has a significant role in neurogenesis, and this may have implications in regeneration of adult neurons.