光疗动力学过程光敏剂及抑制剂效果评价的实验研究

在光疗动力学过程或在生物体光敏氧化过程的控制中,高效廉价的光敏剂或抑制剂的选择是技术的关键。利用光敏剂在光照条件下产生的活性氧氧化二苯基碳酰肼,生成红色二苯基碳酰腙,用三氯化碳萃取;并以无光敏剂时的萃取液为参比,在最大吸收波长563.0nm处测其吸光度值A563;或在该体系中加入抑制剂,以不加抑制剂为参比,计算△A563。实验证明,相同的光照强度与光照时间,用分光光度计测得的A563或△A563/A563值的大小作为快速筛选光敏剂、抑制剂及评价其效果的依据,结果可靠,方法快捷。     

New Metallophthalocyanines Bearing 2-Methylimidazole Moieties—Potential Photosensitizers against Staphylococcus aureus

Newly developed tetra- and octasubstituted methimazole-phthalocyanine conjugates as potential photosensitizers have been obtained. Synthesized intermediates and final products were characterized by the MALD-TOF technique and various NMR techniques, including 2D methods. Single-crystal X-ray diffraction was used to determine the crystal structures of dinitriles. The studied phthalocyanines revealed two typical absorption bands—the Soret band and the Q band. The most intense fluorescence was observed for octasubstituted magnesium(II) phthalocyanine in DMF (Φ_FL = 0.022). The best singlet oxygen generators were octasubstituted magnesium(II) and zinc(II) phthalocyanines (Φ_∆ 0.56 and 0.81, respectively). The studied compounds presented quantum yields of photodegradation at the level between 10⁻⁵ and 10⁻⁶. Due to their low solubility in a water environment, the liposomal formulations were prepared. Within the studied group, octasubstituted zinc(II) phthalocyanine at the concentration of 100 µM activated with red light showed the highest antibacterial activity against S. aureus equal to a 5.68 log reduction of bacterial growth.     

The Role of Melanoma Cell-Derived Exosomes (MTEX) and Photodynamic Therapy (PDT) within a Tumor Microenvironment

Photodynamic Therapy (PDT), an unconventional cancer therapy with optimistic desirable effects, utilizes the delivery of a photosensitizer (PS) that is activated by light at a particular wavelength and inducing oxidative cytotoxic damage of a tumor and its surrounding vasculature. Deeper seated tumors such as internally metastasized melanomas are more difficult to treat with PDT as the penetration of laser light to those sites is less. Limitations in targeting melanomas can also be attributed to melanin pigments that hinder laser light from reaching targeted sites. Exosomes serve as naturally occurring nanoparticles that can be re-assembled with PSs, improving targeted cellular absorption of photosensitizing agents during PDT. Additionally, studies indicate that exosomes released from PDT-treated tumor cells play a critical role in mediating anti-tumor immune responses. This review collates the role of Melanoma Cell-Derived Exosomes (MTEX) in immune response mediation and metastasis. Tumor Cell-Derived Exosomes (TEX) post PDT treatment are also reviewed, as well as the effects of exosomes as carriers of photosensitizers and delivery systems for PDT. The understanding and research on the role of melanoma exosomes induced by Photodynamic Therapy and their tumor microenvironment will assist in future research in treatment prospects and implications.     

跨部门的PDT激励机制研究

针对企业跨部门项目团队内缺乏有效的团队成员激励机制的问题,在对项目成员的能力、风险规避度和团队化程度等因素分析的基础上,提出新的生产函数.基于委托代理理论,建立委托代理激励机制模型并求解,然后对影响PDT项目团队的各因素进行了灵敏度分析,以期为先进生产型企业中跨部门PDT激励机制的建立提供行之有效的指导.经过分析发现,...     

华蟾素联合光动力学疗法对H22肝癌小鼠胃动素、胃泌素影响的实验研究

目的: 探讨华蟾素联合光动力学疗法(PDT)对荷H₂₂肝癌小鼠胃动素、胃泌素的影响。方法: 采用甲脂化叶绿素(MECD)光敏剂联合华蟾素治疗移植性H₂₂肝癌小鼠,测定其抑瘤率及胃动素、胃泌素水平。结果: PDT联合华蟾素组、华蟾素组、PDT组的抑瘤率分别为 51.69%、33.49%、26.50%, PDT治疗后可以使胃动素、胃泌素保持在一定的水平,并减轻化疗引起的呕吐、恶心等消化道反应。结论: 华蟾素联合光动力学疗法可增强H₂₂肝癌小鼠的杀伤效应,同时能明显改善小鼠整体情况,无明显不良反应和副作用,具有可行意义,值得推荐。     

一种新型光敏剂HA激发态敏化单态氧的光谱测量

建立了一种新的测量单态氧荧光光谱和量子产率的方法,定量测定了HA光敏剂敏化单态氧的量子产率。结果表明,测定单态氧在1270nm的荧光光谱,是测定敏化单态氧量子产率的方便而可靠的方法。     

姜黄素光动力技术对水产食品霍利斯格里蒙特菌和溶藻弧菌的灭活作用

目的:研究水溶性姜黄素介导的光动力技术对霍利斯格里蒙特菌和溶藻弧菌的灭活效果及其机理.方法:通过平板菌落计数法测定光动力技术对霍利斯格里蒙特菌和溶藻弧菌的灭活效果,采用试剂盒检测光动力作用后菌体内活性氧水平,利用十二烷基硫酸钠-聚丙稀酰胺凝胶电泳和琼脂糖凝胶电泳分析菌体蛋白降解和基因损伤程度.结果:水溶性姜黄素光动力对...     

竹红菌素光动力抗肿瘤治疗的研究进展

竹红菌素类光动力药物由于其显著的光诱导抗肿瘤作用而受到日益广泛的关注,其高度的选择性和安全性等诸多特性和优点使之成为光动力药物研发领域一类备受瞩目的光敏剂体系。本文综述了近年来竹红菌素类光动力药物文献中关于其在各种疾病治疗研究特别足肿瘤治疗中的研究进展,以及其抗肿瘤机制基本原理和大量学者开展的竹红菌素结构修饰等研究工作成果,展望了竹红菌素类光动力药物在口腔颌面部肿瘤尤其是恶性肿瘤的治疗中的应用前景。     

光动力学疗法中光热效应的有限元法

有限元法(FEM)由Matlab程序实现。生物热传输模型为经典的Pennes方程,加入了血液灌流项,研究了Nd：YAG激光(1064nm)平行光束照射下肝脏组织的温度响应,在轴对称柱坐标下三维温度分布简化为径向、轴向随时间的分布,三维分布彩图还可结合时间作动画显示。数值模拟结果表明,血液灌流在光动力学疗法(PDT)中可避免局部高温,并使温度在很短的时问上升到稳态,如果该稳态温度设为治疗的最佳温度,则可增加疗效并且缩短治疗时间;组织光热参数会影响模拟结果,计算精度和时间也需折衷考虑。     

光动力疗法对荷瘤鼠杀伤作用的组织形态学实验研究

目的：探讨光动力疗法恶性肿瘤杀伤作用的机制。方法：应用光动力疗法对接种H22肝癌的40只昆明小鼠作肿瘤杀伤的对比实验研究。结果：通过组织形态学和抑瘤检测证实，光动力疗法能选择性杀伤癌细胞。结论：在治疗后24小时内就可以见到癌细胞出现空泡变性、核固缩、溶解、坏死，随着时间推移坏死更加明显。同时还证实这种光动力疗法对正常细胞和组织没有损伤。