Disinfection effect of hexadecyl pyridinium chloride on SARS-CoV-2 in vitro.

The novel coronavirus (COVID-19 or 2019-nCoV) is a respiratory virus that can exist in the mouth and saliva of patients and spreads through aerosol dispersion. Therefore, stomatological hospitals and departments have become high-infection-risk environments. Accordingly, oral disinfectants that can effectively inactivate the virus have become a highly active area of research. Hexadecyl pyridinium chloride, povidone-iodine, and other common oral disinfectants are the natural primary choices for stomatological hospitals. Therefore, this study investigated the inhibitory effect of hexadecyl pyridinium chloride on SARS-CoV-2 in vitro. Vero cells infected with SARS-CoV-2 were used to determine the disinfection effect; the CCK-8 method was used to determine cytotoxicity, and viral load was determined by real-time PCR. The results showed that hexadecyl pyridinium chloride has no obvious cytotoxic effect on Vero cells in the concentration range 0.0125-0.05 mg/mL. The in vitro experiments showed that hexadecyl pyridinium chloride significantly inhibits the virus at concentrations of 0.1 mg/mL or above at 2 min of action. Thus, the results provide experimental support for the use of hexadecyl pyridinium chloride in stomatological hospitals.

[Measurement of cortical bone thickness of zygomatic alveolar ridge in adolescents by Cone-beam CT and its correlation with cervical vertebral bone age].

PURPOSE: To measure the cortical bone thickness of zygomatic alveolar ridge in adolescents and explore the correlation between cortical bone thickness and cervical vertebral bone age. METHODS: Cone-beam CT data of 80 adolescents were collected, including 20 adolescents with cervical vertebral bone ages of Cvs3, Cvs4, Cvs5 and Cvs6, respectively. CBCT images were reconstructed with the maxillary occlusal plane as the reference plane. Cortical bone thickness of different slices in the left maxillary zygomatic alveolar ridge area was measured in the direction parallel to and 60° from the reference plane, and the measured data were statistically analyzed by SPSS 21.0 software package. RESULTS: When the measurement direction was parallel to the reference plane and at 60°, the cortical bone thickness in the zygomatic alveolar ridge area of Cvs3-Cvs6 adolescents was (0.90±0.09) -(1.72±0.21) mm and (1.35±0.44)-(3.98±1.48) mm, respectively. There was significant difference in cortical bone thickness between Cvs4 and Cvs5 group(P＜0.05). Spearman correlation analysis showed a strong positive correlation(P＜0.01) between cortical bone thickness of zygomatic alveolar ridge and cervical vertebral bone age in adolescents. CONCLUSIONS: The cortical bone thickness of zygomatic alveolar ridge in adolescents increases with the increase of cervical vertebral bone age, and the cortical bone thickness may increase significantly during Cvs4-Cvs5. In terms of cortical bone thickness, all slices of zygomatic alveolar ridge of CVS3-CVS6 adolescents are suitable for implanting miniscrews, and the anterior slices should be selected for implantation as far as possible for Cvs3 and Cvs4 adolescents.

Functionalities of Gelatin Modified with 2-Octenyl Succinic Anhydride and Gallic Acid.

The aim of this research was to modify gelatin (GT) with 2-octenyl succinic anhydride (OA) and gallic acid (GA) and investigate its functionalities. GT modified with OA (GT-OA) has an improved water solubility at room temperature and an enhanced surface activity, foaming capacity, and pH buffering ability. Regarding antioxidant activity, GT-OA grafted with GA to generate the compound GT-OA-GA has shown good antioxidant activity. Particularly, GT-OA-GA surpassed GA in ferrous ion (Fe2+)-chelating activity. With respect to antimicrobial activity, GT-OA-GA could be complexed with zinc ions (Zn2+), and this complex exhibited good antimicrobial activity against Staphylococcus aureus and Escherichia coli (O157:H7). Chemically modified GT has better water solubility at room temperature and more functionalities than unmodified GT. Thus, it can be used as an emulsifier or coating material in food, cosmetic, and pharmaceutical industries pertaining to GT applications.