This paper dealt with the physicochemical, functional and antioxidative properties of Yak skin gelatins with various molecular weights. The gelatin was extracted by alkaline process, and different molecular weight gelatin was achieved by ultrafiltration with different molecular weight cut membrane. The SDS-PAGE showed the molecular weight of the yak skin gelatin. The UV-Vis absorption turned out that the high molecular weight (HMW) of yak skin gelatin had a higher maximum absorption peaks. The FT-IR indicated the change of gelatin structures with the change of the molecular weight. No matter the HMW or the low molecular weight (LMW), the Yak skin gelatin had a high denaturation temperature (T_d), and it was higher than most of the other mammals and marine biological gelatin. The HMW gelatin had higher imino acids contents and lower oxidation resistance, foamability and emulsibility compared to the LMW gelatin. These findings showed that a certain molecular weight range of Yak skin gelatin has great potential for application as an alternative to commercial gelatin due to its good antioxidative, foamability emulsibility and thermotolerance.

Recently, the incidence rate and mortality of various acute or chronic vascular occlusive diseases have increased yearly. As one of the most effective measures to treat them, vascular stents have been widely studied by researchers, and presently, the most commonly used is a drug-eluting stent, which reduces the process of rapid endothelialization because the drug is not selective. Fortunately, with the discovery and exploration of micro–nanostructures that can regulate cells selectively, reducing the incidence of "intravascular restenosis" and achieving rapid endothelialization simultaneously are possible through a special structure that cannot only improve endothelial cells (ECs), but also inhibit smooth muscle cells (SMCs). Therefore, this paper mainly introduces the preparation methods of micro–nanostructures used in the past, as well as the detection methods of EC and SMC. Then, the various functions of different dimensional structures for different cells are summarized and analyzed. Finally, the application of micro–nanostructure in future stent materials is summarized and proposed.

Introduction:Zuotaiis an ancient mineral-herbal mixture containing β-HgS in Tibetan medicine. It is used to treat nervous system diseases, similar to Chinese medicine cinnabar and Indian Ayurveda medicineRasasindura. However, one of the key problems faced byZuotaiis that its indications are ambiguous. Our previous study found thatZuotaiexhibited the activity of ameliorating depressive-like behaviors in a chronic mild stress model. However, due to the inherent limitations of animal models in simulating human disease, clear results often require more than one model for confirmation.Methods:Therefore, another depression model, chronic restraint stressed (CRS) mice, was used to validate the antidepression effect ofZuotai. Prophylactic treatment was conducted for 21 consecutive days while mice were subjected to chronic restraint stress.Results:It was observed thatZuotaiand β-HgS alleviated anhedonia, behavioral despair, stereotype behavior, and reduced exploratory and spontaneous movement in CRS mice.Zuotaiand β-HgS also reversed the increases of stress hormone corticosterone (Cort) in serum and pro-inflammatory cytokines in serum and brain, and increased the serotonin in cortex in CRS mice, with positive dose-effect relationship. The number of Ki67-positive cells in the dentate gyrus and the level of brain-derived neurotrophic factor (BDNF) in the hippocampus were slightly elevated in CRS mice treated withZuotai; however, there was no statistically significant difference. AlthoughZuotaiincreased the total Hg concentration in main organs, the levels remained below those needed to result in observed adverse effect, at least for kidney and liver; andZuotaishowed no observed adverse effect on the brain histopathology, the cell proliferation in dentate gyrus, as well as the hippocampal and cortical organ coefficients.Conclusion:Zuotaiexhibited the alleviation of depressive-like behaviors in CRS mice, accompanying with ameliorating stress hormone, peripherical and cerebral inflammation, and monoamine neurotransmitter.

Gelatin has been extensively documented for its utility in tissue engineering applications. However, the exploration of yak skin gelatin as a novel gelatin source remains under-reported, particularly regarding the impact of varying molecular weights on the attributes of composite scaffold materials. This study investigates the distinctive behaviors of yak skin gelatin fractions with different molecular weights, assessing fundamental properties through electrophoretic analysis, thermodynamic property assessment, amino acid profiling, infrared spectroscopy, and atomic force microscopy. Then, the polymethyl vinyl ether-alt-maleic-anhydride copolymer (PMVE-MA) was introduced to fabricate the composite scaffold materials. It was observed that the hemolysis rate escalated with increasing gelatin molecular weight. Additionally, properties such as platelet adhesion and mechanical stability exhibited a molecular-weight-dependent threshold behavior. Importantly, no cytotoxic effects were observed across all groups. Notably, scaffold materials fabricated by gelatin with a molecular weight range of 0.1-0.22 μm demonstrated superior mechanical strength and cell adhesion, positioning them as optimal candidates for biodegradable vascular scaffold applications.