CONTEXT: In light of the increased use of zinc oxide nanoparticles in cosumer products such as sunscreens, there is a need for screening the potential dermal toxicity of these nanoparticles. OBJECTIVE: The aim of this study is to identify the risk associated with the nano zinc oxide at realistic exposure levels through dermal route. This study is to understand the toxic potential of nano zinc oxide through repeated dermal exposure for a period of 28 days. MATERIALS AND METHODS: Six- to 8-week-old Sprague-Dawley rats were applied with three different doses (75, 180, and 360 mg/kg body weight) of nano zinc oxide (20 nm) at 5 days/week basis for a period of 28 days. The dose levels were calculated taking into consideration the percentage of nanomaterial in the sunscreen, number of application times, and average weight of the consumer in order to assess the realistic risk related to it. Control group animals were applied with distilled water alone. The collagen content was estimated in skin and tail of all the treated and control animals. RESULTS: The content was significantly decreased in all the nano zinc oxide-treated groups with an inverse dose relationship. DISCUSSION AND CONCLUSION: The percentage collagen loss was high in skin when compared with tail. This may be due to the site of application where in the nano zinc oxide may be passed through skin due to their small size and may induce oxidative stress. Hence, we suggest that regulators and industry need to address the toxicity of nanomaterials with a realistic exposure assessment rather following conventional dose measurements following existing protocols.
CONTEXT: In light of the increased use of zinc oxide nanoparticles in cosumer products such as sunscreens, there is a need for screening the potential dermal toxicity of these nanoparticles. OBJECTIVE: The aim of this study is to identify the risk associated with the nano zinc oxide at realistic exposure levels through dermal route. This study is to understand the toxic potential of nano zinc oxide through repeated dermal exposure for a period of 28 days. MATERIALS AND METHODS: Six- to 8-week-old Sprague-Dawley rats were applied with three different doses (75, 180, and 360 mg/kg body weight) of nano zinc oxide (20 nm) at 5 days/week basis for a period of 28 days. The dose levels were calculated taking into consideration the percentage of nanomaterial in the sunscreen, number of application times, and average weight of the consumer in order to assess the realistic risk related to it. Control group animals were applied with distilled water alone. The collagen content was estimated in skin and tail of all the treated and control animals. RESULTS: The content was significantly decreased in all the nano zinc oxide-treated groups with an inverse dose relationship. DISCUSSION AND CONCLUSION: The percentage collagen loss was high in skin when compared with tail. This may be due to the site of application where in the nano zinc oxide may be passed through skin due to their small size and may induce oxidative stress. Hence, we suggest that regulators and industry need to address the toxicity of nanomaterials with a realistic exposure assessment rather following conventional dose measurements following existing protocols.
Authors: Raziye Mohammadpour; Marina A Dobrovolskaia; Darwin L Cheney; Khaled F Greish; Hamidreza Ghandehari Journal: Adv Drug Deliv Rev Date: 2019-07-08 Impact factor: 15.470
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Authors: Uschi M Graham; Gary Jacobs; Robert A Yokel; Burtron H Davis; Alan K Dozier; M Eileen Birch; Michael T Tseng; Günter Oberdörster; Alison Elder; Lisa DeLouise Journal: Adv Exp Med Biol Date: 2017 Impact factor: 2.622
Authors: Song Tang; Mao Wang; Kaylyn E Germ; Hua-Mao Du; Wen-Jie Sun; Wei-Min Gao; Gregory D Mayer Journal: World J Pediatr Date: 2015-08-08 Impact factor: 2.764
Authors: Soohyun Kim; Brooke Gates; Brian C Leonard; Megan Gragg; Kent E Pinkerton; Laura Van Winkle; Christopher J Murphy; Georgios Pyrgiotakis; Zhenyuan Zhang; Philip Demokritou; Sara M Thomasy Journal: NanoImpact Date: 2019-12-06