Photodynamic therapy (PDT) has been increasingly used in the clinical treatment of neoplastic, inflammatory and infectious skin diseases. However, the generation of reactive oxygen species (ROS) may induce undesired side effects in normal tissue surrounding the treatment lesion, which is a big challenge for the clinical application of PDT. To date, (–)-Epigallocatechin gallate (EGCG) has been widely proposed as an antiangiogenic and antitumor agent for the protection of normal tissue from ROS-mediated oxidative damage. This study evaluates the regulation ability of EGCG for photodynamic damage of blood vessels during hematoporphyrin monomethyl ether (Hemoporfin)-mediated PDT. The quenching rate constants of EGCG for the triplet-state Hemoporfin and photosensitized ¹O₂ generation are determined to be 6.8×108 M^?1S^?1 and 1.5×108 M^?1S^?1, respectively. The vasoconstriction of blood vessels in the protected region treated with EGCG hydrogel after PDT is lower than that of the control region treated with pure hydrogel, suggesting an efficiently reduced photodamage of Hemoporfin for blood vessels treated with EGCG. This study indicates that EGCG is an efficient quencher for triplet-state Hemoporfin and ¹O₂, and EGCG could be potentially used to reduce the undesired photodamage of normal tissue in clinical PDT.

Singlet oxygen (¹O₂) is the main cytotoxic substance in Type II photodynamic therapy (PDT). The luminescence of ¹O₂ at 1270nm is extremely weak with a low quantum yield, making the direct detection of ¹O₂ at 1270nm very challenging. In this study, a set of highly sensitive optical fiber detection system is built up to detect the luminescence of photosensitized ¹O₂. We use this system to test the luminescence characteristics of ¹O₂ in pig skin tissue ex vivo and mouse auricle skin in vivo. The experimental results show that the designed system can quantitatively detect photosensitized ¹O₂ luminescence. The ¹O₂ luminescence signal at 1270nm is successfully detected in pig skin ex vivo. Compared with RB in an aqueous solution, the lifetime of ¹O₂ increases to 17.4±1.2μs in pig skin tissue ex vivo. Experiments on living mice suggest that an enhancement of ¹O₂ intensity with the increase of the TMPyP concentration. When the dose is 25mg/kg, the vasoconstriction can reach more than 80%. The results of this study hold the potential application for clinical PDT dose monitoring using an optical fiber detection system.Singlet oxygen (¹O₂) is the main cytotoxic substance in Type II photodynamic therapy (PDT). The luminescence of ¹O₂ at 1270nm is extremely weak with a low quantum yield, making the direct detection of ¹O₂ at 1270nm very challenging. In this study, a set of highly sensitive optical fiber detection system is built up to detect the luminescence of photosensitized ¹O₂. We use this system to test the luminescence characteristics of ¹O₂ in pig skin tissue ex vivo and mouse auricle skin in vivo. The experimental results show that the designed system can quantitatively detect photosensitized ¹O₂ luminescence. The ¹O₂ luminescence signal at 1270nm is successfully detected in pig skin ex vivo. Compared with RB in an aqueous solution, the lifetime of ¹O₂ increases to 17.4±1.2μs in pig skin tissue ex vivo. Experiments on living mice suggest that an enhancement of ¹O₂ intensity with the increase of the TMPyP concentration. When the dose is 25mg/kg, the vasoconstriction can reach more than 80%. The results of this study hold the potential application for clinical PDT dose monitoring using an optical fiber detection system.

Metal- and metal-oxide-based nanoparticles have been widely exploited in cancer photodynamic therapy (PDT). Among these materials, cerium-based nanoparticles have drawn extensive attention due to their superior biosafety and distinctive physicochemical properties, especially the reversible transition between the valence states of Ce(III) and Ce(IV). In this review, the recent advances in the use of cerium-based nanoparticles as novel photosensitizers for cancer PDT are discussed, and the activation mechanisms for electron transfer to generate singlet oxygen are presented. In addition, the types of cerium-based nanoparticles used for PDT of cancer are summarized. Finally, the challenges and prospects of clinical translations of cerium-based nanoparticles are briefly addressed.Metal- and metal-oxide-based nanoparticles have been widely exploited in cancer photodynamic therapy (PDT). Among these materials, cerium-based nanoparticles have drawn extensive attention due to their superior biosafety and distinctive physicochemical properties, especially the reversible transition between the valence states of Ce(III) and Ce(IV). In this review, the recent advances in the use of cerium-based nanoparticles as novel photosensitizers for cancer PDT are discussed, and the activation mechanisms for electron transfer to generate singlet oxygen are presented. In addition, the types of cerium-based nanoparticles used for PDT of cancer are summarized. Finally, the challenges and prospects of clinical translations of cerium-based nanoparticles are briefly addressed.

光动力疗法(PDT)是一种综合利用光敏剂、光和氧分子，通过光动力反应选择性地治疗恶性肿瘤、血管性病变和微生物感染等疾病的新型疗法。PDT作为光治疗的一种重要方法，已逐渐成为继手术、放疗和化疗之后治疗肿瘤的第四种微创疗法，同时还是治疗鲜红斑痣等特殊疾病的首选疗法。本文简要回顾PDT的研究现状；以提高PDT疗效为目标，重点分析光敏剂、光源、组织氧含量、协同治疗、量效评估等基础研究以及临床应用的研究进展；讨论临床个性化精准PDT及其推广应用所面临的挑战和发展方向。

随着医疗光电产品的升级, 人们对便携式医疗设备和全天候监测医学传感器的需求日益增大。得益于有机电致发光二极管(OLED)的柔性、可拉伸、轻薄、均匀辐照和贴合皮肤表面等优点, 其正成为可穿戴式生物医学设备的新型光源。本文详细介绍了OLED在光动力疗法、光电容积脉搏监测、光吸收式血氧监测、光遗传学和光生物调制等领域的应用进展, 充分展示了OLED在医疗光电产品中的应用潜力。为了满足临床应用对光源的需求, 提高OLED发光功率及延长其寿命是未来的重要发展方向。

光动力疗法(PDT)是一种联合利用光敏剂、光和氧分子,通过光动力反应选择性治疗恶性肿瘤和良性疾病的微创疗法。光源作为PDT的三大关键要素之一,其发光波长、照光方式以及剂量直接决定PDT疗效。针对临床治疗对光源的性能需求,探讨了发光二极管(LED)作为PDT光源的技术优势。深入介绍了LED阵列光源,以及用于发展可穿戴式、可植入式新型PDT光源的有机LED、量子点LED和无线驱动LED的研究进展。全面总结了LED在离体细胞、活体动物以及临床PDT等方面的应用现状。研发波长可切换的多波长LED并实现照光区域和剂量的实时调控是未来智能个性化PDT光源的发展趋势。

光动力疗法(PDT)作为选择性治疗恶性肿瘤和良性疾病的精准靶向疗法,已获得了广泛的临床应用。如何利用先进的光学成像技术实现对PDT剂量的实时监测,是开展PDT个性化精准治疗的理论基础。本文介绍了PDT治疗过程中光敏剂、氧、单线态氧以及血管响应等所需监测的4个重要参量,重点总结了用于实时监测PDT参量的光学成像技术,并比较分析了这些技术的优势和局限性,最后讨论了光学成像技术在PDT临床转化应用中面临的挑战。

光动力疗法(PDT)是一种联合利用治疗光源、光敏剂和氧分子, 选择性治疗恶性肿瘤和良性疾病的精准靶向疗法。光源作为PDT治疗的关键要素之一, 其发光波长、照光方式和剂量直接影响疗效。本文详细介绍了太阳光、近红外光、X射线、在体发光和发光二极管等5种PDT光源的研究新进展, 并分析了这五种治疗光源在生物组织穿透深度上的不同特性以及所存在的不足。随后, 重点讨论了以提高PDT治疗精度为目标的体表照光和体内照光等两种个性化照光模式。研发操作简便、价格低廉、性能优异的新型PDT光源是未来的发展方向。