HMME介导的光动力对兔血管平滑肌细胞生长抑制及诱导细胞凋亡的作用

目的：观察原代培养的兔血管平滑肌细胞在HMME-PDT作用下生长的变化及其死亡方式。方法：常规台盼兰染色观察HMME-PDT作用后6h和24h对细胞的杀伤作用，HMME的浓度为10μg／ml，激光剂帚为2．4～9．6J／cm^2；HE染色法观察PDT后24h细胞形态的变化；流式细胞仪Annexin V／PI双染法检测细胞死亡方式；共聚焦品微镜观察HMME在线粒体的定位。结果：台盼兰法检测结果娃示随着PDT能量密度的增加细胞的存活率逐渐下降，光镜下可见大部分细胞呈死亡或凋亡样改变，Annexin V／PI法检测显示PDT 24h后凋亡率可达50．5％．共聚焦显微镜观察到HMME在线粒体内有分布。结论：HMME-PDT能显著抑制兔血管平滑肌细胞的生长．并使其发生明显的凋亡。     

兔原位直肠癌的光动力治疗效应和不良反应研究

目的 以兔原位直肠癌为动物模型,探讨内镜光动力疗法在治疗腔道肿瘤时照光剂量、操作方法、不良反应等对其疗效的影响,为光动力疗法治疗直肠癌提供临床前依据.方法 建立20只兔VX2原位直肠癌模型,随机分为对照组、PDT低剂量组、PDT中剂量组和PDT高剂量组.血卟啉单甲醚(HMME)光敏剂于PDT前24 h静脉注射兔体内.光源采用630 nm半导体激光器.使用普通内镜和超声内镜观察肿瘤生长情况,并记录生存时间、一般状况、不良反应等.使用苏木精-伊红染色法染色并观察组织病理变化.结果 PDT后第7天,PDT低剂量组40％轻度有效;PDT中剂量组60％明显有效,20％轻度有效;PDT高剂量组20％明显有效,80％轻度有效.PDT低剂量、中剂量、高剂量组的平均生存时间分别为14、10、5d.不良反应主要表现为炎症反应、肠梗阻、肠道蠕动功能丧失以及死亡.结论 PDT剂量是影响疗效的重要因素,合适剂量的PDT对兔直肠癌有较好的消除效果.对这些问题的深入研究有助于PDT治疗直肠癌的临床应用.     

5-ALA诱导白念珠菌生成PpIX与ALA浓度相关性研究

目的 对不同浓度光敏剂5-氨基酮戊酸(5-ALA)在白念珠菌体内生成原卟啉IX (PpIX)进行荧光强度测定,探求PpIX荧光强度与ALA浓度的关系.为光动力治疗白念珠菌选择最佳的光敏剂浓度提供理论依据.方法 实验分为实验组和对照组,将各组白念珠菌悬液与不同浓度5-ALA混合后避光60min孵育.利用共聚焦激光扫描显微镜测量PpIX荧光强度.结果 实验组白念珠菌与不同浓度ALA避光孵育后均有荧光物质PpIX产生,200mg/mL以上ALA浓度组产生的PpIX强度无统计学意义.300mg/mL以下ALA浓度与PpIX生成强度有相关性.对照组没有检测到PpIX.结论 ALA浓度与生成的PpIX荧光强度密切相关.这为临床ALA-PDT治疗白念珠菌疾病提供了实验依据.     

研究不同光敏剂诱导的光动力疗法对人白血病细胞的杀伤作用

目的 研究并比较3种卟啉类光敏剂——血卟啉衍生物(HpD)、癌光啉(PsD007)和血卟啉 单甲醚(HMME)诱导的光动力疗法(PDT)对白血病细胞K562的杀伤效应.方法 以人白血病细胞K562为研究对象,分为对照组和PDT组,以梯度浓度的光敏剂与K562细胞共同孵育,经不同能量光照后,用噻唑蓝(MTT)法测定PDT对K562细胞的杀伤作用.结果 与对照组相比,PDT对K562细胞有明显杀伤作用,并随着光敏剂浓度的增加和光照能量的增大,效果增强.PsD007-PDT和HMME-PDT的效果都明显优于HpD-PDT(P＜0.05);而当光敏剂质量浓度较大(25 μg/ml)或能量密度较大(7.2 J/cm2)时,PsD007-PDT的作用效果优于HMME-PDT.结论 PDT对人白血病细胞K562具有明显的杀伤作用,其对细胞的抑制率具有显著的剂量效应关系;PDT对K562的杀伤效应与光敏剂种类有关,HpD-PDT的杀伤效果不如PsD007和HMME;在较高能量密度和较大光敏剂浓度的条件下,PsD007-PDT的效果优于HMME-PDT.     

HMME-PDT对大鼠致龋模型中变形链球菌抑制作用的研究

目的 探讨不同参数光动力疗法(PDT)在大鼠口腔龋齿预防中的作用.方法 用变形链球菌感染Wistar大鼠口腔,建立龋齿模型.以0.9%生理盐水、0.2%氟化钠为对照组,单纯激光、单纯光敏剂、不同参数PDT为实验组.采用血卟啉单甲醚(HMME)为光敏剂,532 nm半导体激光为光源,每周处理牙齿1次,5周后处死大鼠,Ke...     

DOX联合HMME-PDT对人肝癌细胞HepG2联合作用的研究

目的:初步探讨阿霉素(DOX)联合血卟啉单甲醚介导的光动力疗法(HMME-PDT)对人肝癌细胞(HepG2)的作用及可能的机制.方法:实验分对照组、单独PDT组、单独DOX组和联合作用组.PDT组所用的光敏剂剂量为2.5μg/mL,能量密度为0.2 J/cm2、0.4 J/cm2、0.8 J/cm2、1.6 J/cm2和3.2 J/cm2.DOX组所用的DOX浓度为0.1 μg/mL、0.2μg/mL和0.4μg/mL.联合作用为不同剂量单独作用的组合,联合时序为PDT后立即加入阿霉素(PDT DOX)或阿霉素先于PDT24h加入(DOX PDT).MTT法检测24h后的细胞活性抑制率,并用金氏公式分析联合效应.荧光显微镜观察不同处理组阿霉素的摄取情况.结果:MTT法结果表明,联合作用的细胞抑制率高于单独作用,这在PDT DOX的联合时序作用中表现更为明显.金氏公式分析表明,PDT DOX的联合作用相对DOX PDT的联合作用产生更明显的协同或相加效应.荧光显微镜实验可以观察到联合作用明显提高了细胞对阿霉素的摄取,并且随着联合剂量的加大摄取加强.结论:相对单独作用,联合作用有更高的细胞活性抑制率,联合效应与联合时序有关,PDT DOX的联合作用的联合效果好.联合作用产生相加或协同效应的机制之一可能是因为PDT处理改变了细胞膜通透性从而更有利于细胞对阿霉素的摄取,最终提高作用效果.     

塞来昔布联合血卟啉单甲醚-光动力疗法对人鼻咽癌CNE-2细胞作用的初步研究

目的:探讨环氧化酶-2抑制剂塞来昔布联合血卟啉单甲醚(HMME)光动力对鼻咽癌细胞的作用.方法:实验分对照组、单独PDT组、单独塞来昔布组和联合作用组.光敏剂HMME的剂量为2.5μg/mL,光能量密度分别为0.125 J/cm2、0.25 J/cm2和0.5 J/cm2,MTT法检测各组作用24h后的细胞抑制率,并用金氏公式分析联合效应.HE染色观察细胞形态变化和数量改变.并用Hoechst 33342荧光染色观察细胞核凋亡情况.结果:64 μM和80 μM的塞来昔布对CNE-2细胞的抑制率分别是4.84%和13.23%,2.5μg/mL HMME+0.25 J/cm2 PDT组的抑制率为28.34%,80μM的塞来昔布与2.5μg/mL HMME+0.25 J/cm2 PDT联合组的抑制率为44.57%,金氏公式分析显示在所选的剂量中所有的HMME-PDT与塞来昔布联合处理均有协同或相加效应.HE染色显示,各处理组与对照组相比细胞稀少,形态不规则,部分细胞呈凋亡样改变,联合处理组细胞稀少更明显,死亡细胞更多,Hoechst 33342荧光染色可见细胞核出现明显染色质浓集、核碎裂,核固缩、蓝色荧光强度增加的凋亡现象,联合处理组的细胞死亡更多,凋亡现象更明显.结论:单用塞来昔布或HMME-PDT均能抑制CNE-2细胞的生长,塞来昔布联合HMME-PDT产生相加或协同效应.     

HMME-PDT对人舌鳞癌Tca8113细胞的作用及影响因素初步研究

目的:初步探讨血卟啉单甲醚(HMME)介导的光动力疗法(HMME-PDT)对人舌鳞癌Tca8113细胞的作用及可能的影响因素。方法:以HMME作为光敏剂、发光二极管(LED)为光源的光动力疗法作用于Tca8113细胞。采用MTT法分别检测光敏剂孵育时间、光敏剂浓度、光剂量及光功率密度对Tca8113细胞抑制率的影响。HE染色观察细胞形态学改变,Hoechst 33342荧光染色观察细胞核凋亡情况。结果:细胞抑制率随光敏剂孵育时间延长而增大,呈时间依赖效应;并且随光敏剂浓度和光剂量增加而增大,呈浓度-光剂量依赖效应;在相同光剂量下,抑制率随光功率密度增加而增大,在高剂量时更明显。HE染色显示,与对照组相比,PDT处理组细胞密度明显降低,死细胞明显增多;Hoechst 33342荧光染色可见核染色质浓集、核固缩、核碎裂,出现凋亡小体,呈典型凋亡形态改变。结论:HMME-PDT能有效杀伤Tca8113细胞,光敏剂孵育时间、光敏剂浓度、光剂量及光功率密度以均是影响PDT疗效的重要因素,HMME-PDT主要通过凋亡方式诱导细胞死亡。     

载阿霉素聚合物纳米粒的制备、表征与体内外性能研究

目的 以两亲性三嵌段共聚物聚己内酯-聚乙二醇-聚己内酯(PCL-b-PEG-b-PCL)为载体材料,制备包载抗肿瘤药物阿霉素(DOX)的聚合物纳米粒,并对其进行体内外性能研究.方法 以PCL-b-PEG-b-PCL作为载体材料,通过薄膜水化超声分散法制备出载DOX的聚合物纳米粒,并对其形态、粒径及其分布、载药量及包封率等理化性能进行表征.采用MTS法研究载DOX聚合物纳米粒对EMT6乳腺癌细胞的细胞毒性,激光扫描共聚焦显微镜(CLSM)观察EMT6细胞对纳米粒的细胞吞噬,离体脏器荧光成像研究纳米粒在荷EMT6乳腺癌小鼠的组织分布.结果 通过薄膜水化超声分散法成功制备出载DOX聚合物纳米粒,透射电镜和扫描电镜结果表明,该纳米粒呈球形,大小均匀,具有明显的核壳结构.粒度分析表明,载DOX聚合物纳米粒的平均粒径为130.8 nm,且粒径分布较窄(多分散系数为0.200).DOX在聚合物纳米粒中的包封率和载药量分别为(86.71±2.05)％和(8.71±0.57)％.细胞毒性研究发现,空白纳米粒对EMT6细胞无毒性,而载入DOX后,DOX-NPs的细胞毒性具有时间和剂量依赖性;在DOX质量浓度较高(20 μg/ml和40μg/ml)和孵育时间较长(72 h)时,载DOX聚合物纳米粒与游离DOX的细胞毒性相当,差异无统计学意义(P＞0.05).CLSM观察发现,EMT6乳腺癌细胞与载DOX聚合物纳米粒共同孵育后,DOX的荧光在细胞质和细胞核中均有分布,但与游离DOX共同孵育后,DOX的红色荧光主要出现在细胞核中.离体脏器荧光成像研究表明,分别对荷EMT6乳腺癌小鼠尾静脉注射载DOX聚合物纳米粒及游离DOX后,载DOX聚合物纳米粒可通过增强渗透和滞留效应(EPR)在肿瘤部位有效聚集.结论 载DOX聚合物纳米粒具有适合静脉注射的粒径、高载药量和包封率及良好的被动靶向特性,是一种在肿瘤治疗中具有潜在应用前景的纳米药物递送系统.     

光动力疗法的抗肿瘤机制及光敏剂的研究进展

光动力疗法（PDT）是利用光动力效应对疾病进行诊断与治疗的一种非侵袭性技术,已被用于临床头颈部、乳腺、肺、前列腺及皮肤等部位肿瘤的治疗.与传统治疗方法相比,PDT具有创伤小、毒性低、选择性好、适用范围广及不易产生耐药等优势,因而受到肿瘤治疗领域的广泛关注.PDT的抗肿瘤机制复杂,光敏剂是发挥其光动力学效应的关键因素之一,提高光敏剂的靶向输送和携氧能力是改善光动力疗效的重要途径.对PDT的抗肿瘤机制及光敏剂的研究进展进行综述.     

Photodynamic therapy for nonmelanoma skin cancers. Current review and update

Photodynamic therapy (PDT) is a therapeutic modality involving the use of a photosensitizing agent activated by light to destroy tumor cells. Over the past 25 years, PDT has been shown useful in the treatment of actinic keratoses and certain nonmelanoma skin cancers, such as Bowen's disease and basal cell carcinoma. We review the current data available for PDT with systemic photofrin and topical 5-aminolevulinic acid (ALA). PDT offers many advantages including its non-invasiveness and its ability to treat multiple lesions simultaneously and is, therefore, an interesting alternative for treating certain skin malignancies.     

Progress in the photodynamic therapy treatment of Leishmaniasis

Leishmaniasis is a serious and endemic infectious disease that has been reported in more than 90 countries and territories. The classical treatment presents a series of problems ranging from difficulty in administration, development of resistance, and a series of side effects. Photodynamic therapy (PDT) has already shown great potential for use as a treatment for leishmaniasis that is effective and non-invasive, with very minor side effects. PDT can also be inexpensive and easy to administer. In this review, we will report the most recent developments in the field, starting with the chemical diversity of photosensitizers, highlighting important mechanistic aspects, and noting information that may assist in designing and developing new and promising photosensitizer molecules.     

Targetable micelleplex hydrogel for long-term,effective, and systemic siRNA delivery

We developed a targetable micelleplex hydrogel as a new efficient systemic siRNA delivery material that functions as a targetable gene carrier, and a hydrogel capable of controlled release to overcome drawbacks of multiple administrations of systemic siRNA carriers due to decreased fluctuation of them in the serum. The micelleplexes, complexes between polymeric micelles and siRNAs could turn into gel after subcutaneous injection and be slowly released from the gel. The released micelleplexes selectively accumulated in the tumor and showed anti-tumor effect due to gene silencing for an extended period of time with only one injection in anywhere in vivo model. Moreover, the duration of therapy can be controlled by adjusting the amount and properties of the hydrogel. Therefore, this micelleplex hydrogel is expected to be a new effective siRNA delivery material for systemic long-term gene silencing.     

In vitro release of tegafur from a fatty-base suppository and in vivo bioavailability of tegafur

This study was designed to determine the in vitro release of tegafur from a suppository and the in vivo bioavailability of tegafur in rats. Two different suppository preparations (product A-1 and product A-2) containing 750 mg of tegafur were tested for in vitro release of tegafur by the Muranishi Method (membrane diffusion method) and the partially modified paddle method (permeability through dialysis tubing). When determined by either method, the amount of tegafur released from product A-2 during the whole experimental period was significantly greater than that released from product A-1. When tested by the Muranishi method, however, the difference in the amount released during the first 10-min period was not significant. A greater bioavailability of tegafur after rectal administration was obtained by product A-2 more than product A-1. A significant correlation was observed between the in vitro release and the in vivo bioavailability. The present results indicate that there are considerable differences in physiochemical characteristics between product A-1 and product A-2.     

In vivo release of testosterone from protein-vinyl polymer composites

Hydrophilic vinyl polymer-protein composites containing testosterone were made by means of thermal denaturation of albumin after radiation-induced polymerization of 2-hydroxyethylmethacrylate (HEMA) at −78°C. The albumin-HEMA mixed polymer can be considerably digested with trypsin. The degree of digestion was smaller than that expected from calculation. It was deduced that the digestion of the albumin component was retarded in the presence of HEMA. The same tendency was observed in in vivo experiments. At the same time, in vivo release of testosterone was depressed in albumin-HEMA mixed polymer composite in accordance with the weight decrease of polymer composite resulting from digestion. The effect of testosterone on the weight of ventral prostate was investigated using composites in castrated Wistar rats. The effect was larger in the controlled slow release from implanted composites rather than that of dosage by injection. The microscopic observation showed that the inflammation and foreign body reaction in rat tissue were retarded in albumin-HEMA mixture polymer composite compared with 100% albumin composite.     

PEG-g-chitosan thermosensitive hydrogel for implant drug delivery: cytotoxicity,in vivo degradation and drug release

Thermosensitive hydrogels based on chitosan are of great interests for injectable implant drug delivery. The poly(ethylene glycol)-grafted-chitosan (PEG-g-CS) hydrogel was reported as a potential thermosensitive system. The objective of the present study is to evaluate the cytotoxicity, in vivo degradation and drug release of PEG-g-CS hydrogel. Cytotoxicity was evaluated using L929 murine fibrosarcoma cell line. Degradation and drug release in vivo were investigated by subcutaneous injection of the hydrogel into Sprague-Dawley rats. PEG-g-CS polymer exhibits no significant cytotoxicity when its concentration is less than 3 mg mL^?1. After being implanted, PEG-g-CS hydrogel maintains its integrity for two weeks and collapses, merging into the tissue, in the third week. It causes moderate inflammatory response but no fibrous encapsulation around the hydrogel is found. The hydrogel presents a three-week sustained release of cyclosporine A with no significant burst release in vitro and produces the effective drug concentration in blood for more than five weeks in vivo, performing almost the same bioavailability to chitosan/glycerophosphate hydrogel. Further modifications of PEG-g-CS hydrogel might be necessary to modulate the degradation and to mitigate the fluctuations in blood drug concentration.     

新型光敏剂治疗敏感及耐药胃癌的实验研究

目的 探讨一种新型光敏剂DTP对敏感胃癌细胞(SGC7901)及长春新碱耐药胃癌细胞(SGC7901/VCR)的光动力学治疗作用.方法 采用荧光显微镜间接确认SGC7901及SGC7901/VCR细胞膜上P-糖蛋白(P-gp)的表达情况,细胞计数试剂盒(CCK-8)检测DTP对SGC7901及SGC7901/VCR细胞的光动力学杀伤作用,荧光分光光度计测定两种细胞内的DTP吸收量,激光共聚焦显微镜观察DTP在两种细胞内的分布位置.结果 SGC7901细胞膜上几乎无P-gp分布,而SGC7901/VCR细胞膜上存在P-gp高表达.新型光敏剂DTP对SGC7901及SGC7901/VCR细胞均具有较强的光动力学杀伤作用,其中对SGC7901/VCR细胞的作用相对较弱(P＜0.05),且P-gp抑制剂维拉帕米或环孢素A的存在均不能增强DTP光动力学治疗对SGC7901/VCR细胞的杀伤作用(均P＞0.05).SGC7901细胞内的DTP吸收量高于SGC7901/VCR细胞(P＜0.05),且P-gp抑制剂维拉帕米和环孢素A均不能增加SGC7901/VCR细胞内的DTP吸收量(均P＞0.05).DTP分布于SG-C7901细胞的溶酶体以及SGC7901/VCR细胞的溶酶体和线粒体内.结论 新型光敏剂DTP并非多药转运蛋白P-gp的底物,其对SGC7901/VCR细胞较弱的光动力学杀伤作用与其细胞膜上过表达的P-gp无关,可能与DTP在两种细胞内的分布位置不同有关.