Fabrication of hyaluronic acid-gold nanoparticles with chitosan to modulate neural differentiation of mesenchymal stem cells.

BACKGROUND: Chitosan (Chi) is a natural material which has been widely used in neural applications due to possessing better biocompatibility. In this research study, a novel of nanocomposites film based on Chi with hyaluronic acid (HA), combined with varying amounts of gold nanoparticles (AuNPs), was created resulting in pure Chi, Chi-HA, Chi-HA-AuNPs (25 ppm), and Chi-HA-AuNPs (50 ppm). METHODS: This study focused on evaluating their effects on mesenchymal stem cell (MSC) viability, colony formation, and biocompatibility. The surface morphology and chemical position were characterized through UV-visible spectroscopy (UV-Vis), Fourier-transform infrared spectroscopy (FTIR), SEM, and contact-angle assessment. RESULTS: When seeding MSCs on Chi-HA-AuNPs (50 ppm), the results showed high cell viability, biocompatibility, and the highest colony formation ability. Meanwhile, the evidence showed that Chi-HA-Au nanofilm was able to inhibit nestin and ß-tubulin expression of MSCs, as well as inhibit the ability of neurogenic differentiation. Furthermore, the results of matrix metalloproteinase 2/9 (MMP2/9) expression in MSCs were also significantly higher in the Chi-HA-AuNP (50 ppm) group, guiding with angiogenesis and wound healing abilities. In addition, in our rat model, both capsule thickness and collagen deposition were the lowest in Chi-HA-AuNPs (50 ppm). CONCLUSION: Thus, in view of the in vitro and in vivo results, Chi-HA-AuNPs (50 ppm) could not only maintain the greatest stemness properties and regulate the neurogenic differentiation ability of MSCs, but was able to also induce the least immune response. Herein, Chi-HA-Au 50 ppm nanofilm holds promise as a suitable material for nerve regeneration engineering.

Electrospun Polylactic Acid (PLLA) Microtube Array Membrane (MTAM)-An Advanced Substrate for Anticancer Drug Screening.

The advent of personalized cancer treatment resulted in the shift from the administration of cytotoxic drugs with broad activity spectrum to a targeted tumor-specific therapy. Aligned to this development, the focus of this study revolved around the application of our novel and patented microtube array membrane (MTAM) in the US National Cancer Institute (NCI) developed an HFA (hollow fiber assay) assay; hereinafter known as MTAM/HFA. Electrospun poly-L-lactic acid (PLLA) MTAM was sterilized and loaded with cell lines/patient derived tumor cells (PDTC) and subcutaneously implanted into the backs of BALB/C mice. Anticancer drugs were administered at the respective time points and the respective MTAMs were retrieved and the viability tumor cells within were quantified with the MTT assay. Results revealed that the MTAMs were excellent culture substrate for various cancer cell lines and PDTCs (patient derived tumor cells). Compared to traditional HFA systems that utilize traditional hollow fibers, MTAM/HFA revealed superior drug sensitivity for a wide range of anticancer drug classes. Additionally, the duration for each test was <14 days; all this while capable of producing similar trend outcome to the current gold-standard xenograft models. These benefits were observed in both the in vitro and in vivo stages, making it a highly practical phenotypic-based solution that could potentially be applied in personalized medicine.