Tannic Acid-Assisted Immobilization of Copper(II), Carboxybetaine, and Argatroban on Poly(ethylene terephthalate) Mats for Synergistic Improvement of Blood Compatibility and Endothelialization.

Due to thrombosis and intimal hyperplasia, small-diameter vascular grafts have poor long-term patency. A combination strategy based on nitric oxide (NO) and anticoagulants has the potential to address those issues. In this study, poly(ethylene terephthalate) (PET) mats were prepared by electrospinning and coated with tannic acid (TA)/copper ion complexes. The chelated copper ions endowed the mats with sustained NO generation by catalytic decomposition of endogenous S-nitrosothiol. Subsequently, zwitterionic carboxybetaine acrylate (CBA) and argatroban (AG) were immobilized on the mats. The introduced AG and CBA had synergistic effects on the improvement of blood compatibility, resulting in reduced platelet adhesion and prolonged blood clotting time. The biocomposite mats selectively promoted the proliferation and migration of human umbilical vein endothelial cells while inhibiting the proliferation and migration of human umbilical arterial smooth muscle cells under physiological conditions. In addition, the prepared mats exhibited antibacterial activity against Escherichia coli and Staphylococcus aureus. Collectively, the prepared mats hold great promise as artificial small-diameter vascular grafts.

Nitric oxide releasing poly(vinyl alcohol)/S-nitrosated keratin film as a potential vascular graft.

Nitric oxide (NO) releasing vascular graft is promising due to its merits of thromboembolism reduction and endothelialization promotion. In this study, keratin-based NO donor of S-nitrosated keratin (KSNO) was blended with poly(vinyl alcohol) (PVA) and further crosslinked with sodium trimetaphosphate (STMP) to afford PVA/KSNO biocomposite films. These films could release NO sustainably for up to 10 days, resulting in the promotion of HUVECs growth and the inhibition of HUASMCs growth. In addition, these films displayed good blood compatibility and antibacterial activity. Taken together, these films have potential applications in vascular grafts.

Impact of COVID-19 on advanced dental education: Perspectives of dental residents in Wuhan.

PURPOSE: This study investigated the impact of coronavirus disease 2019 (COVID-19) from the perspectives of dental residents in Wuhan, the former COVID-19 epicenter of China. METHODS: A survey form was sent to 424 residents in the School of Stomatology, Wuhan University (WHUSS) in September 2020. The form included 23 questions on demographics, study situation of residents during the COVID-19 outbreak, effect of COVID-19 on graduates, and status of residents who returned to clinic training. RESULTS: A total of 361 (85%) survey forms were collected. Over 70% of respondents felt anxious during Wuhan lockdown. Most respondents continued studying (94%) mainly through free online resources (79%). The majority reported improvement in didactic knowledge (80%), but the respondents' perceptions of their clinical skills, especially those in Wuhan, did not change (41%) or worsened (40%) (p < 0.05). Most graduates (88%) reported having found jobs or continued study. Among the 209 responders who returned to clinical training, 52% felt no concern about COVID-19 infection, 89% thought they were equipped with adequate personal protective equipment (PPE), and 57% indicated that they received sufficient knowledge for preventing COVID-19 in clinic. Most respondents agreed that the way to gain the knowledge for preventing COVID-19 in clinic was training at dental school (93%). CONCLUSION: Although online study has been appreciated by residents, concern about clinical skill learning in the COVID-19 hardest-hit area has arisen. Most graduates felt that the impact of COVID-19 on their immediate postgraduation career was limited. Teaching about infection control in dental schools seemed effective to develop a positive attitude for residents after they returned to clinical training.