Meesaragandla Brahmaiah, Sarkar Debashrita, Mahalingam Venkataramanan
Department of Chemical Sciences and Center for Advanced Functional Materials (CAFM), Indian Institute of Science Education and Research (IISER) Kolkata, Mohanpur, West Bengal 741252, India.
ACS Omega. 2019 Feb 13;4(2):3169-3177. doi: 10.1021/acsomega.8b02416. eCollection 2019 Feb 28.
The property of upconverting nanoparticles to convert the low-energy near-infrared (NIR) light into high-energy visible light has made them a potential candidate for various biomedical applications including photodynamic therapy (PDT). In this work, we show how a surface functionalization approach on the nanoparticle can be used to develop a nanocomposite hydrogel which can be of potential use for the PDT application. The upconverting hydrogel nanocomposite was synthesized by reacting 10-undecenoic acid-capped Yb/Er-doped NaYF nanoparticles with the thermosensitive -isopropylacrylamide monomer. The formation of hydrogel was completed within 15 min and hydrogel nanocomposites showed strong enhancement in the visible light emission compared to the emission obtained from 10-undecenoic acid-capped Yb/Er-doped NaYF nanoparticles via the upconversion process (under 980 nm laser excitation). The upconverting hydrogel nanocomposites displayed high swelling behavior in water because of their porous nature. The porous structure ensured a higher loading of methylene blue dye (∼78% in 1 h) into the upconverting hydrogel, which was achieved via the swelling diffusion phenomenon. Upon excitation with the NIR light, the visible light emitted from the hydrogel activated the photosensitizer methylene blue which generated reactive oxygen species. Our results were able to show that the methylene blue-loaded composite hydrogel can be a potential platform for the future of NIR-triggered PDT in skin cancer treatment.
上转换纳米粒子具有将低能量近红外（NIR）光转换为高能量可见光的特性，这使其成为包括光动力疗法（PDT）在内的各种生物医学应用的潜在候选材料。在这项工作中，我们展示了如何通过纳米粒子表面功能化方法来开发一种纳米复合水凝胶，这种水凝胶在PDT应用中可能具有潜在用途。通过使10-十一碳烯酸封端的Yb/Er掺杂NaYF纳米粒子与热敏性N-异丙基丙烯酰胺单体反应，合成了上转换水凝胶纳米复合材料。水凝胶的形成在15分钟内完成，与通过上转换过程（在980 nm激光激发下）从10-十一碳烯酸封端的Yb/Er掺杂NaYF纳米粒子获得的发射相比，水凝胶纳米复合材料在可见光发射方面有显著增强。由于其多孔性质，上转换水凝胶纳米复合材料在水中表现出高溶胀行为。多孔结构确保了亚甲基蓝染料更高的负载量（1小时内约78%）进入上转换水凝胶，这是通过溶胀扩散现象实现的。在用近红外光激发时，水凝胶发出的可见光激活了光敏剂亚甲基蓝，从而产生活性氧。我们的结果表明，负载亚甲基蓝的复合水凝胶可能成为未来皮肤癌治疗中近红外触发光动力疗法的潜在平台。
