Biosafety and Antibacterial Ability of Graphene and Graphene Oxide In Vitro and In Vivo

Abstract In recent years, graphene (G) and graphene oxide (GO) nanoparticles have begun to be applied in surgical implant surface modification. However, biosafety and antibacterial ability of G and GO are still unclear. In this study, the biosafety of G and GO in vitro was evaluated by co-culture with bone marrow mesenchymal stem cells (BMSCs) and biosafety in vivo was observed by implanting materials into mice muscle tissue. Biosafety results showed that 10 μg/ml was the safety critical concentration for G and GO. When the concentration was more than 10 μg/ml, the cytotoxicity of G and GO showed a dose-dependent manner. Antibacterial results showed that G presented the antibacterial ability with the concentration equal to and more than 100 μg/ml; GO presented the antibacterial ability with the concentration equal to and more than 50 μg/ml. The antibacterial effect of G and GO were in a dose-dependent manner in vitro. The GO or G concentration between 50 and 100 μg/ml may be the better range to keep the balance of cytotoxicity and antibacterial ability. Our study reveals that G and GO have potential to be used in clinic with good biosafety and antibacterial properties in a certain concentration range

Does the 2017 global initiative for chronic obstructive lung disease revision really improve the assessment of Chinese chronic obstructive pulmonary disease patients? A multicenter prospective study for more than 5 years

Abstract. Background:. The Global Initiative for Chronic Obstructive Lung Disease (GOLD) 2017 proposed a new classification that reclassified many chronic obstructive pulmonary disease (COPD) patients from group D to B. However, there is a paucity of data related to the comparison between reclassified and non-reclassified COPD patients in terms of long-term prognosis. This study aimed to investigate long-term outcomes of them and determine whether the GOLD 2017 revision improved the assessment of COPD patients. Methods:. This observational, multicenter, prospective study recruited outpatients at 12 tertiary hospitals in China from November 2016 to February 2018 and followed them up until February 2022. All enrolled patients were classified into groups A to D based on GOLD 2017, and the subjects in group B included patients reclassified from group D to B (group DB) and those remaining in group B (group BB). Incidence rates and hazard ratios (HRs) were calculated for the exacerbation of COPD and hospitalization in each group. Results:. We included and followed up 845 patients. During the first year of follow-up, the GOLD 2017 classification had a better discrimination ability for different risks of COPD exacerbation and hospitalization than GOLD 2013. Group DB was associated with a higher risk of moderate-to-severe exacerbation (HR = 1.88, 95% confidence interval [CI] = 1.37–2.59, P <0.001) and hospitalization for COPD exacerbation (HR = 2.23, 95% CI = 1.29–3.85, P = 0.004) than group BB. However, during the last year of follow-up, the differences in the risks of frequent exacerbations and hospitalizations between group DB and BB were not statistically significant (frequent exacerbations: HR = 1.02, 95% CI = 0.51–2.03, P = 0.955; frequent hospitalizations: HR = 1.66, 95% CI = 0.58–4.78, P = 0.348). The mortality rates of the two groups were both approximately 9.0% during the entire follow-up period. Conclusions:. The long-term prognosis of patients reclassified into group B and of those remaining in group B was similar, although patients reclassified from group D to group B had worse short-term outcomes. The GOLD 2017 revision could improve the assessment of Chinese COPD patients in terms of long-term prognosis