聚合物纳米粒在肿瘤光动力治疗中的研究进展

光动力治疗创伤小,在恶性肿瘤治疗方面的应用已经得到了临床认可。治疗过程中需要给予光敏剂,在光照下产生分子氧对肿瘤细胞产生杀伤作用。但是,大多数光敏剂缺乏对肿瘤细胞的特异性,其在肿瘤中的富集主要与细胞高代谢有关,并且在水相媒介中溶解度比较差。纳米技术应用于光动力治疗提供了一种有效地体内运输光敏剂的方式。目前,聚合物纳米粒与光动力药物传递的研究越来越多,光敏剂通过纳米粒的运输为弥补光动力治疗的不足提供了可能,这是因为纳米载体可以将治疗浓度的光敏剂运送到肿瘤细胞而不造成非靶向组织的副损伤。本文将介绍对肿瘤光动力治疗中具有特异性的聚合物纳米粒的种类及在临床中的应用情况,为肿瘤靶向治疗提供新思路。     

光动力疗法中氧的弥散模型仿真及其意义

组织中的氧是由血管中扩散而来,存在一定的差异。光动力疗法使用的卟啉类光敏剂主要是通过将能量转移到氧分子产生单线态氧来产生毒性物质,因此在光动力治疗中有氧的消耗,使组织中氧分布对光动力作用具有特殊意义。本文对氧在靶组织和正常组织中的分布、光动力效应对组织中氧含量的影响、以及氧含量对光动力效应的反作用等方面进行了综述。     

光动力学疗法的单态氧剂量学研究进展

单态氧(1O2)是光动力学疗法(photodynamic therapy,PDT)过程中Ⅱ型光化学反应的主要细胞毒性物质.通过直接测量1O2发光强度预测PDT疗效已成为PDT剂量学研究的前沿热点,这种方法的最大优点在于能够克服现有其它剂量学方法中的光、光敏剂、氧分子,以及组织光学特性等因素之间的复杂相互影响,将PDT的...     

光动力疗法在腹部恶性肿瘤的应用

近年来光动力治疗已经应用在腹部的恶性肿瘤的治疗上,并且取得了满意的疗效.对于部分腹部恶性肿瘤,相应的研究在实验室里也有报道.通过对光动力治疗的原理、机制、光敏剂,以及腹部恶性肿瘤光动力治疗相关的文献进行了综述,总结了光动力治疗应用在腹部恶性肿瘤的优势和相关问题.     

光动力疗法对肿瘤的作用机制及其影响因素

光动力疗法（photodynamic therapy,PDT）被提出可用于肿瘤治疗已有25年历史。最近几年,PDT在临床上得到了较广泛的应用。一些光敏剂已被某些国家批准作为PDT药物。有关新型光敏剂的合成、体内体外试验、作用机制等方面的研究得到了迅速的发展,并取得了丰硕的成果。现从光动力反应基本原理出发,回顾了有关肿瘤PDT作用机制特别是细胞水平作用机制及其影响因素的最新研究成果。对肿瘤PDT作用机制进行全面深入的探讨,将有助于寻找改善和加强PDT功效的方法,使其在肿瘤治疗中发挥更大的优势。     

肿瘤干细胞的光动力治疗研究进展

肿瘤干细胞(cancerstem cells,CSCs)是在肿瘤组织中具有干细胞特性的细胞亚群,它具有正常干细胞的多向分化潜能,能够无限增值和自主分化为各种具有异质性的肿瘤细胞。CSCs在肿瘤的发生、生长、转移中起着重要作用。同时,CSCs对目前大多数治疗如化疗、放疗不敏感,甚至具有耐药性,这也就导致了恶性肿瘤在治疗后容易复发。鉴于此,针对肿瘤干细胞的治疗日益受到关注,光动力疗法(photodynamictherapy,PDT)由于其微创性,不良反应少,靶向性强等特点在肿瘤的治疗研究中不断得到发展。本文将从CSCs的特性入手,结合PDT治疗的最新进展,探讨PDT治疗在肿瘤干细胞治疗中的应用。     

光动力技术治疗胃癌的进展及展望

近年来应用光动力技术治疗胃癌取得了可喜的进步,它对各个时期的胃癌均有比较满意的临床效果。本文通过对国内外近年来用光动力技术治疗胃癌方面的文献进行综述,系统阐述光动力运用于胃癌治疗这一项技术的原理、机制,光敏剂、光源及临床效果等方面,并总结了这项技术在治疗胃癌方面的优点和相关问题。     

Mechanistic Insight into the Photodynamic Effect Mediated by Neutral Red and a New Azine Compound in Staphylococcus aureus Cells

The photodynamic activity of Neutral Red and the new monobrominated Neutral Red was studied in suspensions of Staphylococcus aureus. The effect of mannitol and sodium azide in the presence of 25 μm photosensitizer on lethal photosensitization were investigated. The results of the mechanistic evaluation of Neutral Red showed that both mannitol and sodium azide produced a completed protective effect after irradiation without significant differences between them. The evaluation of monobrominated Neutral Red also showed a protective effect of microorganisms with the addition of mannitol. Although sodium azide produced a protective effect of the photoinactivation, it was incomplete and less than that exhibited by mannitol. The results indicate that the starting reagent, Neutral Red, is a producer of radical species, acting through a type I mechanism, whereas the halogenated derivative of Neutral Red produced reactive oxygen species and a contribution of singlet molecular oxygen cannot be discarded in the photoinactivation of Staphylococcus aureus cells. These results, analyzed together with the previously evaluated properties of the dyes, allow us to explain the differences observed in the photoinactivation of Staphylococcus aureus mediated by both azine photosensitizers.     

抗氧化剂辅助疗法对光动力疗法疗效的影响

研究食物中含有的天然抗氧化剂对光动力疗法治疗效果的影响。通过在常规培养的K562细胞悬浮液中分别加入染料木素、鞣花酸、山竹黄酮这几种天然抗氧剂,用戊氨基乙酰丙酸-光动力疗法（ALA—PDT）作用后,检测各组细胞的存活率。研究发现染料木素、鞣花酸、山竹黄酮均可以提高光动力疗法的疗效。研究结果表明,抗氧化剂疗法和光动力疗法相互结合能够起到良好的治疗效果。     

痂囊腔菌素A对动物实体肿瘤的光动力治疗

从生物学角度研究了痂囊腔菌素A（EA）对黑色素瘤B-16实体肿瘤的光敏生物活性,实验结果显示,EA对黑色素瘤B-16实体肿瘤生长具有良好的抑制、杀伤效果,表明EA具有光敏抗肿瘤活性。     

Photodynamic treatment with anionic nanoclays containing curcumin on human triple-negative breast cancer cells: Cellular and biochemical studies

Photodynamic treatment is a minimally invasive and clinically approved procedure for eliminating selected malignant cells with activation of a photosensitizer agent at a specific light. Little is known, however, about the phototoxic properties of curcumin, as a natural phenolic compound, against different types of cancers. It is generally accepted that cellular damage occurs during photo treatment. There is a limitation in using of curcumin as a drug due to its low solubility, but nanoparticles such as anionic nanoclays or layered double hydroxide (LDH) could overcome it. The aim of this study was to investigate cellular responses to curcumin-LDH nanoparticles after photodynamic treatment of MDA-MB-231 human breast cancer cells. For this purpose, the MDA-MB-231 human breast cancer cell line treated with curcumin-LDH nanoparticle and then irradiated (photodynamic treatment). After irradiation, lactate dehydrogenase assay, clonogenic cell survival, cell death mechanisms such as autophagy and apoptosis were determined. Cell cycle distribution after photodynamic therapy (PDT) and also intracellular reactive oxygen species (ROS) generation were measured. The result showed that curcumin-LDH–PDT has a cytotoxic and antiprolifrative effect on MDA-MB-231 human breast cancer cells. Curcumin-LDH–PDT induced autophagy, apoptosis, and G0/G1 cell cycle arrest in human breast cancer cell line. Intracellular ROS increased in MDA-MB-231 cancer cell line after treatment with curcumin-LDH along with irradiation. The results suggest that curcumin-LDH nanoparticle could be considered as a novel approach in the photodynamic treatment of breast cancer.     

一种新型细胞摄取增强的两亲性卟啉类光敏剂及肿瘤光动力治疗研究

光敏剂能否被肿瘤细胞高效吸收是影响光动力治疗效率的重要因素。亲脂性光敏剂易于被肿瘤组织摄取,但会使光敏剂发生自猝灭;亲水性光敏剂则有利于光敏剂在体内的转运,但肿瘤细胞摄取率会下降。本工作通过亲酯性的乙二醇缩合支链和亲水性季膦基团与卟啉相连接,成功制备一种新型两亲性卟啉锌化合物(ZnTP-TP),实验表明该化合物具有较高的单线态氧量子产率和良好的两亲性,可被细胞快速摄取,并表现出较低的细胞毒性和良好的肿瘤光动力治疗效应。     

带有功能性多肽的光敏剂及其应用

光动力治疗( photodynamic therapy,PDT )是光敏剂在特定波长光源的激发下、在氧分子存在下产生细胞毒性物质的一种治疗方法,主要用于抗肿瘤治疗．目前临床应用的光敏剂对肿瘤细胞的靶向性比较有限,近来的一个热门研究方向是靶向性光敏剂．结合作者多年来在该方向的工作,综合近年来光敏剂研究的发展,比较全面地阐述了带有功能性多肽的靶向性光敏剂及其在光动力治疗中的应用．阐述多肽作为靶向基团的优势,总结了包括透膜多肽、血管靶向多肽、细胞受体靶向多肽等功能多肽与光敏剂偶合物的生物效应,说明了多肽能够实现光敏剂的靶向作用．     

藻蓝蛋白色素肽光动力学抗肿瘤作用的实验研究

目的：探讨藻蓝蛋白色素肽的理化特性及光动力疗法（PDT）抗肿瘤效果。方法：用柱层析法从螺旋藻藻蛋白酶介产物中分离色素肽,并用MTT法及吖啶橙染色法检测色素肽对体外培养的小鼠肉瘤细胞S180及荷瘤小鼠PD。结果：分离出三种色素肽的分子量分别为17.4KD,7.72KD及6.6KD,它们的吸收光谱峰值分别位于618nm,580nm,605nm,荧光发射峰均在685nm处。MTT法检测证明,在浓度100μg/ml,用波长为580nm,600nm,照射剂量为28.8J/cm^2染料激光（氩离子为激光光源）照射,对肿瘤细胞的杀伤率达69．2％－80．2％;在色素肽CCP1,CCP3介导的PDT对小鼠移植瘤生长影响的实验发现,色素肽易被瘤细胞吸收,当激光照射剂量为120J/cm^2,肿瘤直径在0.5-0.7cm范围内,瘤体旁注射剂量为50μg的CPP1及CCP3光敏剂时,藻胆蛋白酶介产的的抑瘤率可达46％－81％,且被PDT作用后的细胞表现了典型的凋亡细胞特征。     

光动力学疗法治疗肝胆肿瘤的研究现状

介绍了光动力学疗法治疗肝胆肿瘤的实验室和临床研究现状,提出了光动力学疗法在治疗肝胆肿瘤面临的问题,并建议在腹腔镜手术中引入光动力学疗法,认为随着新型光敏剂及光源的开发应用,PDT将会成为治疗肝胆肿瘤的切实可行方法。     

High-Frequency Ultrasound Assessment of Antimicrobial Photodynamic Therapy In Vitro

Ultrasound imaging is proving to be an important tool for medical diagnosis of dermatological disease. Backscatter spectral profiles using high-frequency ultrasound (HFUS, 10–100 MHz) are sensitive to subtle changes in eukaryotic cellular morphology and mechanical properties that are indicative of early apoptosis, the main type of cell death induced following photodynamic therapy (PDT). We performed experiments to study whether HFUS could also be used to discern changes in bacteria following PDT treatment. Pellets of planktonic Staphylococcus aureus were treated with different PDT protocols and subsequently interrogated with HFUS. Changes in ultrasound backscatter response were found to correlate with antimicrobial effect. Despite their small size, distinct changes in bacterial morphology that are indicative of cell damage or death are detectable by altered backscatter spectra from bacterial ensembles using HFUS. This highlights the potential for HFUS in rapidly and non-invasively assessing the structural changes related to antimicrobial response.     

Precise ligand engineering of Ir(III)-based photosensitizer with aggregation-induced emission for image-guided photodynamic therapy

Photodynamic therapy (PDT), which relies on the production of reactive oxygen species (ROS) induced by a photosensitizer to kill cancer cells, has become a non-invasive approach to combat cancer. However, the conventional aggregation-caused quenching effect, as well as the low ROS generation ability of photosensitizers, restrict their biological applications. In this work, a new Ir(III) complex with a dendritic ligand has been strategically designed and synthesized by ingenious modification of the ancillary ligand of a reported Ir(III) complex ( Ir-1 ). The extended π-conjugation and multiple aromatic donor moieties endow the resulting complex Ir-2 with obvious aggregation-induced emission (AIE) activity and bathochromic emission. In in vitro experiments, importantly, Ir-2 nanoparticles exhibit the excellent photoinduced ROS generation capabilities of O₂^•− and ¹O₂, as well as excellent biocompatibility and the lipid droplets (LDs) targeting feature. This study would provide useful guidance to design efficient Ir(III)-based photosensitizers used in biological applications in the future.     

Antimicrobial photodynamic activity of toluidine blue encapsulated in mesoporous silica nanoparticles against Pseudomonas aeruginosa and Staphylococcus aureus

In the present study, the antimicrobial and antibiofilm efficacy of toluidine blue (TB) encapsulated in mesoporous silica nanoparticles (MSN) was investigated against Pseudomonas aeruginosa and Staphylococcus aureus treated with antimicrobial photodynamic therapy (aPDT) using a red diode laser 670?nm wavelength, 97.65?J cm^?2 radiant exposure, 5?min). Physico-chemical techniques (UV-visible (UV-vis) absorption, photoluminescence emission, excitation, and FTIR) and high-resolution transmission electron microscopy (HR-TEM) were employed to characterize the conjugate of TB encapsulated in MSN (TB MSN). TB MSN showed maximum antimicrobial activities corresponding to 5.03 and 5.56 log CFU ml^?1 reductions against P. aeruginosa and S. aureus, respectively, whereas samples treated with TB alone showed 2.36 and 2.66 log CFU ml^?1 reductions. Anti-biofilm studies confirmed that TB MSN effectively inhibits biofilm formation and production of extracellular polymeric substances by P. aeruginosa and S. aureus.     

评估光动力血管损伤的光学监测技术

血管靶向光动力疗法(Vascular targeted photodynamic therapy,V-PDT)已成为临床治疗鲜红斑痣和老年黄斑变性等血管性疾病的重要方法。V-PDT通过主动或被动血管靶向的作用机制诱发系列生物响应以封闭病变血管。本文评述了V-PDT的作用机制和血管生物学响应,重点讨论了用于评估V-PDT中血管损伤的光谱与成像技术,并分析了这些技术的优点和局限性。最后展望了用于评估V-PDT血管损伤的光学技术发展及其应用前景。