共查询到18条相似文献,搜索用时 106 毫秒
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《分析化学》2014,(3):461
肿瘤的高效、高选择性治疗是癌症治疗研究的热点。与传统的癌症治疗(手术、放疗、化疗)技术不同,光动力治疗用光激发光敏剂,将能量传递给周围的分子氧(3O2),产生具有瞬时强氧化性的单线态氧(1O2),这种1O2可破坏肿瘤组织和癌细胞,实现癌症的高效治疗。在光动力治疗研究领域,光敏剂的设计与选择是其核心问题。目前临床使用的光敏剂,大多对肿瘤组织或细胞选择性不高,导致肿瘤组织周围的正常组织也受到损伤,而且病人在接受光动力治疗以后仍需长时间避光以减轻皮肤红肿、色素沉着等光毒性反应。因此,寻找新型光敏剂以实现1O2在肿瘤组织和细胞中的选择性释放是光动力治疗技术应用的关键问题。 相似文献
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具有创伤小、毒性低、选择性好、无耐药性等优点的光动力疗法已被广泛应用于癌症治疗研究。然而,多数光敏剂存在水溶性差易聚集、肿瘤组织选择性差的问题,且其激发光都在可见或紫外光范围内,组织穿透深度较浅导致治疗深度不够,限制了光动力疗效。稀土上转换纳米粒子具有低生物毒性、高化学稳定性、强组织穿透力等优点,可作为将近红外光转换成紫外/可见光的发光材料和光敏剂载体,因此,构建上转换光动力诊疗体系为增强光动力疗效提供新思路。本文介绍了上转换光动力诊疗体系的构建方法,包括物理吸附法、物理包封法、共价偶联法,并分析了其应用于光动力抗癌研究的优缺点,最后总结并展望了其存在的挑战及未来发展方向。 相似文献
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光动力治疗因其无创、可控和不易产生耐药性等显著优点,成为一种新型的肿瘤靶向治疗模式。光敏化过程涉及光敏剂对氧分子的光激活反应,然而实体肿瘤的乏氧环境严重限制了传统有机光敏剂的疗效。金属铱配合物具有良好的光物理和光化学性质,是理想的新一代光敏剂,近些年,铱光敏剂被发现可以应用于乏氧肿瘤的光动力治疗。本文总结了近些年金属铱配合物应用于乏氧肿瘤光动力治疗的研究;同时介绍了基于铱配合物的乏氧纳米复合体系的构建和乏氧肿瘤的光动力治疗研究,为开发新型高效的乏氧肿瘤治疗光敏剂及其载体提供参考。 相似文献
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光动力治疗(Photodynamic therapy,PDT)作为一种有别于传统癌症治疗方式的新型疗法,近些年来受到了科学家们越来越多的关注.它凭借着自身创伤性小,毒性低微,适用性好,可协同手术治疗以及可重复治疗等独特优势,在许多肿瘤的治疗方面有着广泛的应用.本文简要概述了光动力疗法的原理以及光敏剂的发展历程,并对理想光敏剂的特点作了总结.目前,以酞菁类化合物为主的第三代光敏剂已经成为光动力疗法的研究热点,然而如何提高光敏剂分子的靶向性达到精准的光动力治疗仍然是亟待解决的问题.因此,主要综述了近年来靶向性酞菁类光敏剂的研究进展,并对未来光敏剂的重点研究方向做出了展望.从目前来看,如何克服癌症低氧微环境的限制,发展Type I型不依赖氧的体系以及光穿透力强的靶向光敏剂在光动力治疗方面存在着巨大的潜质,有望成为新一代十分优良的光动力疗法用光敏剂. 相似文献
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Aisling E. O'Connor William M. Gallagher Annette T. Byrne 《Photochemistry and photobiology》2009,85(5):1053-1074
Photodynamic therapy (PDT) is now a well-recognized modality for the treatment of cancer. While PDT has developed progressively over the last century, great advances have been observed in the field in recent years. The concept of dual selectivity of PDT agents is now widely accepted due to the relative specificity and selectivity of PDT along with the absence of harmful side effects often encountered with chemotherapy or radiotherapy. Traditionally, porphyrin-based photosensitizers have dominated the PDT field but these first generation photosensitizers have several disadvantages, with poor light absorption and cutaneous photosensitivity being the predominant side effects. As a result, the requirement for new photosensitizers, including second generation porphyrins and porphyrin derivatives as well as third generation photosensitizers has arisen, with the aim of alleviating the problems encountered with first generation porphyrins and improving the efficacy of PDT. The investigation of nonporphyrin photosensitizers for the development of novel PDT agents has been considerably less extensive than porphyrin-based compounds; however, structural modification of nonporphyrin photosensitizers has allowed for manipulation of the photochemotherapeutic properties. The aim of this review is to provide an insight into PDT photosensitizers clinically approved for application in oncology, as well as those which show significant potential in ongoing preclinical studies. 相似文献
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Nory Mariño-Ocampo Luciano Dibona-Villanueva Elizabeth Escobar-Álvarez Daniel Guerra-Díaz Daniel Zúñiga-Núñez Denis Fuentealba José Robinson-Duggon 《Photochemistry and photobiology》2023,99(2):469-497
Photodynamic therapy of cancer (PDT) is a therapeutic technique, minimally invasive, which is currently used to treat cancerous lesions and tumors that have been in the spotlight for its potential over the recent decades. Nonetheless, PDT still needs further development to become a first-option treatment for patients. This review compiles recent progress in several aspects of the current research in the constantly growing area of PDT to overcome the main challenges as an attempt to serve as a guide and reference for newcomers into this research area. This review has been prepared to highlight the use of chemical modifications on photosensitizers to improve their solubility, photostability, selectivity and phototoxicity. Additionally, the use of liposomes and cavitands as drug delivery systems to aid in the biodistribution and bioaccumulation of photosensitizers is presented. Also, the combination of PDT with chemotherapy or immunotherapy as an option to boost and improve treatment outcomes is discussed. Finally, the inhibition of antioxidant enzymes as a strategy for a synergistic effect to ameliorate the performance of the photosensitizers in PDT is presented as an alternative for future researchers. 相似文献
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Photodynamic therapy (PDT) and photodynamic antimicrobial chemotherapy (PACT) combine light and photosensitizers to treat cancers and microbial infections, respectively. In PACT, the excitation of a photosensitizer drug with appropriate light generates reactive oxygen species (ROS) that kill pathogens in the proximity of the drug. PACT has considerably advanced with new light sources, biocompatible photosensitizers, bioconjugate methods, and efficient ROS production. The PACT technology has evolved to compete with or replace antibiotics, reducing the burden of antibiotic resistance. This review updates recent advances in PACT, with special references to light sources, photosensitizers, and emerging applications to microbial infestations. We also discuss PACT applied to COVID-19 causing SARS-CoV-2 treatment and disinfecting food materials and water. Finally, we discuss the pathogen selectivity and efficiency of PACT. 相似文献
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Pérez-Prieto J Pérez LP González-Béjar M Miranda MA Stiriba SE 《Chemical communications (Cambridge, England)》2005,(44):5569-5571
Combination of the pyrene and benzoylthiophene units constitutes an interesting approach to design bichromophoric photosensitizers with increased intersystem crossing quantum yield and enhanced selectivity. The potential of this strategy has been illustrated in the present work by using a model photoisomerization reaction. 相似文献
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David A. Bellnier David N. Young Michael R. Detty Susan H. Camacho Allan R. Oseroff 《Photochemistry and photobiology》1999,70(4):630-636
Ideal photosensitizers have long-wavelength absorption and strong tumor selectivity with rapid clearance from normal tissues. The telluroselenopyrylium dye 1 that absorbs light at 795 nm (epsilon = 285,000 M-1 cm-1) has a novel property that enhances the tumor specificity and normal tissue clearance. After intralesional injection to both tumors and surrounding skin, it disappeared from the normal skin of BALB/c mice faster than it did from subcutaneously implanted Colon 26 tumors, which resulted in therapeutic selectivity. In vivo reflectance spectroscopy showed that the half-life in tumor was about 50 min while in skin it was around 12 min. This phenomenon appears to be related to the pH differences in normal skin versus tumor, because the rates of drug hydrolysis in solution were shown to be sensitive to changes in pH. Inhibition of tumor regrowth following intratumoral photosensitizer administration depended on both light dose and drug dose, as well as the time interval between dye injection and irradiation; selectivity depended on the time interval. Although treatment parameters were not optimized efficacy was superior to systemic Photofrin under our standard conditions. We discuss how new, more optimal, photosensitizers can be designed that use rates of hydrolysis to exploit the differences in pH between normal tissue and tumor. 相似文献
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The role of the low density lipoprotein receptor pathway in the delivery of lipophilic photosensitizers in the photodynamic therapy of tumours 总被引:2,自引:0,他引:2
J C Mazière P Morlière R Santus 《Journal of photochemistry and photobiology. B, Biology》1991,8(4):351-360
Lipoproteins are now recognized as major blood carriers of many hydrophobic porphyrins and related chromophores which are being investigated as possible photosensitizers in the photodynamic therapy of tumours. In vitro and in vivo studies have demonstrated the role of the low density lipoprotein (LDL) receptor pathway in the delivery of photosensitizers to tumour cells and its importance in porphyrin accumulation by tumours. Lysosomes, which are involved in the cellular processing of LDL, are important intracellular targets in the LDL-porphyrin-induced phototoxicity. The use of the LDL receptor pathway as a tool for enhancing the selectivity of photosensitizer delivery to tumour cells appears to be a promising field of research in the photodynamic therapy of tumours. 相似文献
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Highly Efficient,Conjugated‐Polymer‐Based Nano‐Photosensitizers for Selectively Targeted Two‐Photon Photodynamic Therapy and Imaging of Cancer Cells 下载免费PDF全文
Dr. Xiaoqin Shen Shuang Li Dr. Lin Li Prof. Shao Q. Yao Prof. Qing‐Hua Xu 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(5):2214-2221
Two‐photon photodynamic therapy (2P‐PDT) is a promising noninvasive treatment of cancers and other diseases with three‐dimensional selectivity and deep penetration. However, clinical applications of 2P‐PDT are limited by small two‐photon absorption (TPA) cross sections of traditional photosensitizers. The development of folate receptor targeted nano‐photosensitizers based on conjugated polymers is described. In these nano‐photosensitizers, poly{9,9‐bis[6′′‐(bromohexyl)fluorene‐2,7‐ylenevinylene]‐co‐alt‐1,4‐(2,5‐dicyanophenylene)}, which is a conjugated polymer with a large TPA cross section, acts as a two‐photon light‐harvesting material to significantly enhance the two‐photon properties of the doped photosensitizer tetraphenylporphyrin (TPP) through energy transfer. These nanoparticles displayed up to 1020‐fold enhancement in two‐photon excitation emission and about 870‐fold enhancement in the two‐photon‐induced singlet oxygen generation capability of TPP. Surface‐functionalized folic acid groups make these nanoparticles highly selective in targeting and killing KB cancer cells over NIH/3T3 normal cells. The 2P‐PDT activity of these nanoparticles was significantly improved, potentially up to about 1000 times, as implied by the enhancement factors of two‐photon excitation emission and singlet oxygen generation. These nanoparticles could act as novel two‐photon nano‐photosensitizers with combined advantages of low dark cytotoxicity, targeted 2P‐PDT with high selectivity, and simultaneous two‐photon fluorescence imaging capability; these are all required for ideal two‐photon photosensitizers. 相似文献
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A paper in this issue of Photochemistry and Photobiology by Cassidy et al. describes the use of a sophisticated drug delivery vehicle prepared by the hot melt extrusion process to deliver photosensitizers to the colon. The smart vehicle protects its cargo through the acidic environment of the stomach but releases the active photosensitizers in the higher pH and anaerobic environment of the colon. The goal is to use photodynamic therapy (PDT) to destroy pathogenic microorganisms that can cause disease when they grow out of control in the colon. Since the colon is an environment with a low oxygen concentration the investigators also used tetrachlorodecaoxide, an oxygen donor to boost the available oxygen concentration. The paper reports results with Enterococcus faecalis and Bacteroides fragilis but the real medical problem demanding to be solved is Clostridium difficile that can cause intractable drug-resistant infections after antibiotic use. There still remain barriers to implementing this strategy in vivo, including light delivery to the upper colon, oxygen availability and optimizing the selectivity of photosensitizers for bacteria over colon epithelial cells. Nevertheless, this highly innovative paper lays the ground for the study of an entirely new and significant application for antimicrobial PDT. 相似文献