Exposure to polystyrene microplastics reduces regeneration and growth in planarians.

The potential adverse effects of microplastics (MPs) on ecosystems and human health have received much attention in recent years. However, only limited data are available on the mechanisms for the uptake, distribution, and effects of MPs in freshwater organisms, especially with respect to tissue repair, regeneration and impairment of stem cell functions. To address this knowledge gap, we conducted exposure experiments in which planarians (Dugesia japonica) were exposed to polystyrene (PS)-MPs mixed in liver homogenate and examined the tissue growth and regeneration, stem cell functions, and oxidative stress. The body and blastema areas decreased upon exposure to PS-MPs, indicating that the growth and regeneration of planarians were delayed. The proliferation and differentiation processes of stem cells were inhibited, and the proportion of mitotic stem cells decreased, which may be related to the activation of the TGFß/SMAD4 and Notch signaling pathways. The enhancement of antioxidant enzyme activities and malondialdehyde on the first day of exposure to PS-MPs confirmed the oxidative stress response of planarians to PS-MPs. The present study demonstrated the likelihood of biotoxicity induced by PS-MPs. These results will provide clues for further investigations into the potential risks of PS-MPs to human stem cells.

Comparison of fibrin glue versus suture for conjunctival autografting in pterygium surgery: a meta-analysis.

PURPOSE: To evaluate the safety and clinical efficacy of fibrin glue in pterygium surgery with conjunctival autografting. DESIGN: The use of fibrin glue has been introduced in the treatment of pterygium. However, its role versus traditional suturing is still a matter of debate. We performed a meta-analysis to compare the safety and clinical efficacy of fibrin glue with suture for conjunctival autograft attachment in pterygium surgery. PARTICIPANTS: A total of 342 participants with 366 eyes in 7 studies were analyzed. METHODS: We searched Medline, EMBASE, Web of Science, Cochrane Central Register of Controlled Trials, and Google Scholar for relevant randomized controlled trials (RCTs). MAIN OUTCOME MEASURES: The methodological quality of all the included trials was assessed with the Jadad score. The meta-analysis was performed with the fixed-effects model for complication rate and recurrence rate, and random-effects model for operating time. RESULTS: Fibrin glue was associated with a significantly decreased operating time (weighted mean difference -17.61 minutes, 95% confidence interval [CI], -26.03 to -9.18, P<0.0001) and was more effective in reducing the recurrence rate (Peto odds ratio [OR] 0.33, 95% CI, 0.15-0.71, P = 0.004) compared with suture. There were no significant differences in the complication rate (Peto OR 1.82, 95% CI, 0.63-5.27, P = 0.27) between the 2 groups. CONCLUSIONS: Our meta-analysis supports the superiority of fibrin glue to suture in pterygium surgery with conjunctival autografting in that the use of fibrin glue can significantly reduce the recurrence rate without increasing the risk of complications. Ophthalmologists should consider the use of fibrin glue in pterygium surgery. FINANCIAL DISCLOSURE(S): The author(s) have no proprietary or commercial interest in any materials discussed in this article.