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Liu J, Kang Y, Yin S, et al. Int J Nanomedicine. 2017;12:8085–8099. The authors have advised the control images for Figure 4A and B were the same to represent the one and the same control group. To alleviate any potential confusion this may have created, the authors have provided a corrected Figure 4. This correction does not change the scientific conclusions of the article in any way. Figure 4 Confocal microscopy investigation of the cellular distribution of lysosomes and zinc ions in SH-SY5Y cells after the two types of ZnO NP treatments.Abbreviation: NP, nanoparticle.Notes: After the SH-SY5Y cells were untreated (the Control group) or treated with the ZnOa NPs and ZnOb NPs (50 µg/mL) for 1 h, 3 h, or 5 h, the cells were loaded with FluoZin3 (green), LysoTracker (red) and Hoechst 33342 (blue). We observed almost no zinc ion fluorescence in the Control group, but significant zinc ions (green) were observed within 1 h after the ZnO NP treatment, and a slight increase in the zinc fluorescence (green) was observed in a time-dependent manner. Treatment with ZnOb NPs exhibited more potent fluorescence values than treatment with ZnOa NPs at 1 h. Moreover, significant overlaps (yellow) between cellular zinc ions and lysosomes were observed at all timepoints. Scale bar = 50µm. Magnification x600.

Rapid and effective bone regeneration is still a major challenge in the clinical treatment of various bone diseases. Although recently developed electroactive materials have demonstrated high bone regeneration potential, the instability of the electrical stimulation and the unclear effects of the charge polarity on osteogenic differentiation hinder their clinical applications. In this work, GaN/AlGaN materials with well-controlled polarity are used for the first time to induce endogenous electric stimulation and facilitate bone regeneration. By controlling the direction and magnitude of the piezoelectric and spontaneous polarization in the functional layer (GaN), charged GaN/AlGaN surfaces of opposite polarity, whose zeta potentials are within the range of the physiological potential, are obtained. Compared with N-polarity GaN/AlGaN (with a positively charged surface), Ga-polarity GaN/AlGaN (with a negatively charged surface) nanofilms show rapid and superior bone repair in vivo. In addition, the Ga-polarity GaN/AlGaN hetero-structures significantly promote the attachment, spreading, recruitment, and osteogenic differentiation of bone mesenchymal stem cells in vitro. Moreover, the bone morphogenetic protein-6 (BMP6) expression profile in the early stages of osteogenic differentiation reveals that BMP6 may be an electrically sensitive osteogenic protein. This work sheds light on the application of III-nitride materials in bone regeneration. © 2020 Wiley-VCH GmbH

Jia Liu,1 Yiyuan Kang,1 Suhan Yin,1 Bin Song,2 Limin Wei,3 Liangjiao Chen,4 Longquan Shao1 1Department of Stomatology, Nanfang Hospital, Southern Medical University, Guangzhou, 2Department of Stomatology, Guizhou Provincial People’s Hospital, Guiyang, 3Department of Pediatric Dentistry, School and Hospital of Stomatology, Wenzhou Medical University, Wenzhou, 4Key Laboratory of Oral Medicine, Guangzhou Institute of Oral Disease, Stomatology Hospital of Guangzhou Medical University, Guangzhou, China Abstract: Due to the widespread applications of zinc oxide nanoparticles (ZnO NPs), the potential exposure of workers, consumers, and scientists to these particles has increased. This potential for exposure has attracted extensive attention in the science community. Many studies have examined the toxicological profile of ZnO NPs in the immune system, digestive system, however, information regarding the toxicity of ZnO NPs in the nervous system is scarce. In this study, we detected the cytotoxicity of two types of ZnO NPs of various sizes – ZnOa NPs and ZnOb NPs – and we characterized the shedding ability of zinc ions within culture medium and the cytoplasm. We found that reactive oxygen species played a crucial role in ZnO NP-induced cytotoxicity, likely because zinc ions were leached from ZnO NPs. Apoptosis and cytoskeleton changes were also toxic responses induced by the ZnO NPs, and ZnOb NPs induced more significant toxic responses than ZnOa NPs in SHSY5Y cells. In conclusion, ZnO NPs induced toxic responses in SHSY5Y cells in a size-dependent manner, which can probably be attributed to their ion-shedding ability. Keywords: zinc oxide, nanoparticles, SHSY5Y cells, reactive oxygen species, apoptosis, cell cytoskeleton

Yiyuan Kang, Jia Liu, Junrong Wu, Qian Yin, Huimin Liang, Aijie Chen, Longquan Shao Nanfang Hospital, Southern Medical University, Guangzhou, People’s Republic of China Abstract: Given the novel applications of graphene materials in biomedical and electronics industry, the health hazards of these particles have attracted extensive worldwide attention. Although many studies have been performed on graphene material-induced toxic effects, toxicological data for the effect of graphene materials on the nervous system are lacking. In this study, we focused on the biological effects of graphene oxide (GO) and reduced graphene oxide (rGO) materials on PC12 cells, a type of traditional neural cell line. We found that GO and rGO exerted significant toxic effects on PC12 cells in a dose- and time-dependent manner. Moreover, apoptosis appeared to be a response to toxicity. A potent increase in the number of PC12 cells at G0/G1 phase after GO and rGO exposure was detected by cell cycle analysis. We found that phosphorylation levels of ERK signaling molecules, which are related to cell cycle regulation and apoptosis, were significantly altered after GO and rGO exposure. In conclusion, our results show that GO has more potent toxic effects than rGO and that apoptosis and cell cycle arrest are the main toxicity responses to GO and rGO treatments, which are likely due to ERK pathway regulation. Keywords: graphene oxide, reduced graphene oxide, PC12, cell cycle alterations, ERK pathway