Skin protection against ultraviolet (UV) radiation is necessary to reduce sunburn damage (erythema) and has been recognized as an important preventive measure against the development of cancer. Many sun-blocking pharmaceutical products are based on titanium dioxide nanomaterials (TiO₂ NMs) due to their UV barrier properties. This study aimed to assess if the UV protective efficiency of TiO₂ NMs depends on their shape. We prepared TiO₂ nanowires (TNW), TiO₂ nanotubes (TNT), and TiO₂ nanoplates (TNP) and tested their effects on human keratinocytes before and after UVB irradiation under in vitro exposure settings. The UVB radiation was applied at the dose equivalent to the UV component observed in one medial erythemal dose. The biological effects of TiO₂ NMs on nonirradiated and UVB-irradiated keratinocytes were observed by means of cell viability, genotoxicity, and inflammatory response. The obtained results clearly showed that the effects of TiO₂ NMs in vitro, either cytotoxic or protective, depend on their shape. These observations highlight the beneficial properties of nanomaterials that can improve the quality and efficacy of nano-enabled products only if the safe-by-design concept has been implemented during the innovation process.

防止紫外线（UV）辐射的皮肤防护对于减少晒伤（红斑）必不可少，并且已被公认为是预防癌症发展的重要预防措施。由于其紫外线阻隔性能，许多防晒药物产品都基于二氧化钛纳米材料（TiO ₂ NMs）。这项研究旨在评估TiO ₂ NMs的紫外线防护效率是否取决于其形状。我们准备了TiO ₂纳米线（TNW），TiO ₂纳米管（TNT）和TiO ₂纳米板（TNP）并测试了它们在体外暴露设置下对UVB照射前后对人角质形成细胞的影响。UVB辐射的剂量等于在一个内侧红斑剂量中观察到的UV成分。通过细胞活力，遗传毒性和炎症反应，观察了TiO ₂ NMs对未照射和UVB照射的角质形成细胞的生物学作用。所获得的结果清楚地表明，TiO ₂ NMs在体外的细胞毒性或保护性效应取决于其形状。这些观察结果突出了纳米材料的有益特性，只有在创新过程中实施了按设计安全的概念时，纳米材料才能改善纳米产品的质量和功效。