[A Novel Lyophilized PRP-Loaded Gel Based on Chitosan and PEG with Hemostatic and Antibacterial Properties].

OBJECTIVE: A dynamic gel loaded with lyophilized platelet-rich plasma-chitosan/difunctionalized polyethylene glycol (LPRP-CP) was prepared to investigate its hemostatic antibacterial and promoting wound healing of scald wounds through in vitro and in vivo experiments. METHODS: In this study, normal gauze/blank tablet (Ctrl), LPRP-CP, Chitosan HUCHUANG Powder(Chito P)and ChitoGauze XP PRO group (Chito G group) were set. The hemostatic effect and promoting healing effect of the four groups of materials were evaluated by establishing rabbit ear artery hemorrhage model and superficial Ⅱ° scalded model of skin on the back. The hemostatic time and bleeding amount were calculated and the gross and histological results of scald healing were observed. The antibacterial effect of the four groups of materials was evaluated by antibacterial test in vitro. RESULTS: In the rabbit ear arterial hemorrhage model, the hemostasis of all materials was successful. The hemostatic time of Ctrl, Chito P, LPRP-CP and Chito G groups was 213.33±38.30, 118.33±24.01, 115.00±8.37 and 111.67±11.69 s, respectively. The blood loss was 1233.83±992.27, 346.67±176.00, 193.33±121.47 and 147.50±80.66 mg, respectively. Compared with Ctrl, the hemostasis time of LPRP-CP, Chito P and Chito G group was significantly shorter (P<0.001), and the amount of blood loss of LPRP-CP and Chito G group was decreased (P<0.05). Compared with LPRP-CP, there were no significant differences in hemostatic time and blood loss between Chito P and Chito G group (P>0.05). In the model of superficial Ⅱ° scalded on the back of rabbit, the wound healing rate of LPRP-CP was faster than that of the other three groups at the same time, and the healing effect was perfect. In the antibacterial test in vitro, only LPRP-CP had better anti-S. aureus effect, and all groups had no anti-E. coli effect. CONCLUSION: LPRP-CP is an excellent hemostatic material for superficial wounds, and has certain antibacterial and wound healing effects, which has a wide academic value and research prospects.

New insights into mechanism of bisphenol analogue neurotoxicity: implications of inhibition of O-GlcNAcase activity in PC12 cells.

Bisphenol analogues including bisphenol A and its derivatives are ubiquitous environmental contaminants and have been linked to adverse neurodevelopment effects on animals and humans. Most toxicological research focused on estrogen receptor mediated pathways and did not comprehensively clarify the observed toxicity. O-GlcNAcase (OGA), the highest level in brain, plays a critical role in controlling neuronal functions at multi-levels from molecule to animal behaviors. In this work, we intend to investigate the underlying molecular mechanisms for the neurotoxicity of bisphenol analogues by identifying their cellular targets and the resultant effects. The inhibitory actions of seven bisphenol analogues on the OGA activity at molecular level were investigated by our developed electrochemical biosensor. We found that their potency varied with substituent groups, in which tetrabromo bisphenol A (TBBPA) was the strongest. The seven bisphenol analogues (0-100 µM exposure) significantly inhibited OGA activity and up-regulated protein O-GlcNAcylation level in PC12 cells. Inhibition of OGA by bisphenol analogues further induced intracellular calcium, ROS, inflammation, repressed proliferation, interfered with cell cycle, induced apoptosis. And especially, 10 µM tetrabromo bisphenol A (TBBPA) exposure could impair the growth and development of neurite in human neural stem cells (hNSCs). Molecular docking for OGA/bisphenol analogue complexes revealed the hydrophobicity-dominated inhibition potency. OGA, as a new cellular target of bisphenol analogues, would illuminate the molecular mechanism of bisphenol analogues neurotoxicity.