放疗联合光动力疗法治疗肿瘤的研究进展

放疗联合光动力疗法(PDT)在治疗肿瘤方面日益受到人们的关注,从细胞水平、动物水平及临床应用等方面的研究进展来看,放疗联合传统PDT可以提高肿瘤治疗效果,降低放疗剂量,减少不良反应的发生。尤其近年发展起来的自发光光动力疗法可以不再需要额外的光源,与放疗的联合应用在降低辐射剂量的同时,亦有效解决了外部光源穿透力弱、诱发PDT效应差的弊端。自发光光动力疗法比放疗与传统PDT的简单联合应用更具优势,是目前研究的热点。就放疗联合光动力疗法治疗肿瘤的研究进展予以综述。     

肿瘤光动力治疗疗效评价标准2014共识(第1版)

近年来肿瘤治疗除了手术、放疗和化疗之外,微创治疗越来越盛行,其中肿瘤光动力治疗以其选择性好、重复性好、保护器官功能和容貌等优势在微创治疗中越来越引人注目。随着光动力治疗相关光敏剂和激光治疗仪得到临床准入许可,国内很多医疗机构都已开展肿瘤光动力治疗,目前肿瘤光动力治疗在临床应用越来越广泛。但是肿瘤光动力治疗的     

肿瘤光动力疗法：理论基础及治疗策略

肿瘤的传统治疗方案主要包括手术治疗、放疗及化疗等,而光动力疗法（Photodynamic therapy,PDT）是肿瘤治疗领域内一项新的、引人注目的方法。它的基本过程是利用特定波长的光照射选择性蓄积在病变处的光敏剂,光敏剂随之活化并与氧分子作用产生具有细胞毒性的单线态氧及活性氧物质,经过直接与间接作用最终导致肿瘤细胞死亡。光动力疗法治疗肿瘤副作用小,对实体肿瘤尤其是浅表性肿瘤,如皮肤基底细胞癌等有着良好的治疗效果。光敏剂、光及组织氧是现代光动力疗法概念的重要组成部分。本文回顾并综述了光动力疗法的理论基础及治疗策略。     

肿瘤光动力治疗疗效评价标准2014共识（第1版）

近年来肿瘤治疗除了手术、放疗和化疗之外,微创治疗越来越盛行,其中肿瘤光动力治疗以其选择性好、重复性好、保护器官功能和容貌等优势在微创治疗中越来越引人注目。随着光动力治疗相关光敏剂和激光治疗仪得到临床准入许可,国内很多医疗机构都已开展肿瘤光动力治疗,     

肿瘤光动力治疗疗效评价标准2014共识（第1版）

近年来肿瘤治疗除了手术、放疗和化疗之外,微创治疗越来越盛行,其中肿瘤光动力治疗以其选择性好、重复性好、保护器官功能和容貌等优势在微创治疗中越来越引人注目。随着光动力治疗相关光敏剂和激光治疗仪得到临床准入许可,国内很多医疗机构都已开展肿瘤光动力治疗,目前肿瘤光动力治疗在临床应用越来越广泛。     

普外科

不耐受手术晚期直肠癌的光动力治疗初步观察。目的:探讨光动力疗法对不能耐受手术的晚期直肠癌是否有效。方法:晚期直肠癌手术患者31例,同时选择同期肿瘤期别患者作为对照组,行光动力治疗,两组患者均为不能耐受手术或拒绝手术、同时不接受放疗或化疗的晚期患者。两组患者在性别、年龄和肿瘤分期上比较,差异无统计学意义(P>0.05)。     

光动力灭菌研究进展

细菌引起的感染是临床上常见的问题,尤其是抗生素耐药菌的出现给医疗卫生工作带来了严峻考验。光动力疗法是治疗肿瘤、血管性疾病的一种新的方法。目前的研究表明光动力疗法可以有效杀伤致病菌,为治疗感染性疾病提供了一种新的思路。本文为光动力灭菌影响因素、其作用位点方面研究进展的综述。随着新型光敏剂的不断开发、光动力影响因素研究的深入、光动力治疗方法的不断成熟,光动力灭菌将具有广阔的应用前景。     

光敏剂的临床应用及研究进展

光动力治疗（photodynamic therapy,PDT）是利用光敏剂在相应波长光照射下产生光动力反应治疗疾病的一种新技术。作为PDT中至关重要的因素,光敏剂的研究受到越来越多的重视。本文对目前临床常用光敏剂进行了总结和评价,并对新型光敏剂在光动力治疗中的应用研究进行了综述。     

一种新型酞菁锌磺酸衍生物ZnPcSmix对人肺癌细胞系（A549）作用的研究

背景 肺癌在全球癌症中占12.7%,高于乳腺癌（10.9%）和结直肠癌（1.23%）,通常采用手术,化疗,放疗等方法治疗,但副作用很多。光动力疗法（PDT）有助于提高癌症患者的疗效。但第一代光敏剂光卟啉存在化学异质性高,红光的吸收低,     

光动力抗菌化学疗法治疗难治性细菌感染性疾病的研究进展

由于全球范围内抗生素耐药性越来越烈,新的抗感染策略的研究迫在眉睫。光动力抗菌化学疗法是基于光动力疗法的原理,利用光敏剂和光杀灭多重耐药菌的一种新抗感染疗法。该疗法是一种很有前景的治疗难治性细菌感染性疾病的新策略。笔者就近年来光动力抗菌化学疗法治疗难治性细菌性感染性疾病的研究进展及其机制进行综述。     

Photodynamic therapy in cholangiocarcinoma: an overview

Cholangiocarcinoma is a challenge to manage; mortality rate is nearly as high as the incidence. Unless curative resection is performed, these tumours are rapidly fatal because they respond poorly to current therapies. Symptoms occur late in cholangiocarcinoma and curative resection can be performed in less than half of the patients. In non-resectable disease, endoprostheses insertion can relieve jaundice and improve quality of life, provided that tumour extension does not lead to diffuse intrahepatic stenoses of ductal system. However, tumour growth cannot be influenced and therefore, prognosis remains dismal. Despite the fact, that radiotherapy and chemotherapy could reduce tumour volume and growth, no survival advantage has yet been shown.Photodynamic therapy has been evaluated as an new additional, palliative option. A randomised trial comparing photodynamic therapy plus endoprostheses insertion versus endoprostheses insertion alone, indicates a considerably benefit on survival time, cholestasis and quality of life in large, advanced cholangiocarcinoma. Furthermore, few specific side effects occurred. Since photodynamic therapy is the first approach leading to an improvement of prognosis, it should be offered to patients with non-resectable cholangiocarcinoma.     

Targeted radionuclide therapy for bone metastases

Recent advances in targeted radiotherapy offer a new approach for the management of metastatic bone pain. This paper will review the scientific basis for radionuclide therapy and will examine the evidence for clinical efficacy. The therapeutic potential of targeted radiotherapy can only be appreciated by comparison with established treatments. Alternative treatment options will, therefore, be discussed, to bring the potential advantages and hazards of targeted radiotherapy into perspective and to define its place in routine management.     

Interstitial photodynamic therapy for prostate cancer: a developing modality

Patients with early stage prostate cancer are generally treated with either a radical prostatectomy or radiotherapy. While both approaches have good survival outcomes, they are associated with significant side effects and non-trivial failure rates. Photodynamic therapy has been studied as a possible treatment for both recurrent and primary prostate cancer. Interstitial photodynamic therapy requires strict dosimetry, mandating an understanding of photosensitizer concentration, tissue oxygenation, and light fluence. Preclinical studies have investigated the optical characteristics of prostate tissue showing variability both prior to and during photodynamic therapy. Canine studies have been undertaken demonstrating necrosis of the glandular epithelium to depths ranging from 1 to 17 mm from a single light source depending on the photosensitizer used. Necrosis is typically followed by glandular atrophy with maintenance of the gross prostatic architecture. Urinary complications in the canine studies were more prominent when transurethral light was used and often occurred in a dose-dependent fashion. Few clinical trials have been undertaken to date investigating photodynamic therapy of the prostate in patients. The limited data that are available suggest that photodynamic therapy is tolerable in patients with recurrent and primary disease. This review summarizes the preclinical and clinical work in photodynamic therapy in the prostate and suggests areas of future research which must be addressed before the technique can become a practical option for patients.     

Photodynamic therapy and endoscopic mucosal resection as minimally invasive approaches for the treatment of early esophageal tumors: Pre-clinical and clinical experience in Lausanne

Esophageal cancer, when detected at an early stage, has a very good probability of being eradicated by surgery or radiotherapy. However, less aggressive treatments also tend to provide high rates of cure without the side effects of radical surgery or radiotherapy. Among them, photodynamic therapy and endoscopic mucosal resection have been experienced as alternative techniques for mucosal ablation in patients with superficial squamous-cell carcinoma (SCC) of the esophagus, or high-grade dysplasia and early stage adenocarcinoma arising in Barrett's esophagus. We report on the results of our clinical experience with photodynamic therapy and discuss about its advantages and limitations. We also present a pre-clinical study, which had evaluated the feasibility, efficacy, and safety of a promising new method of endoscopic mucosal resection (EMR) based on the use of a modified rigid esophagoscope. The animal model chosen was the sheep because of its similarities with humans regarding the thickness and histologic structure of the esophagus. This new resection modality offers a promising approach in comparison with other options currently available, namely EMRs performed with flexible gastroscopes. It appears to be superior in terms of the size of the resected specimen, the precision and regularity of the resection depth, and the accuracy of histological diagnosis with safety margins.     

Nanodrug applications in photodynamic therapy

Photodynamic therapy (PDT) has developed over last century and is now becoming a more widely used medical tool having gained regulatory approval for the treatment of various diseases such as cancer and macular degeneration. It is a two-step technique in which the delivery of a photosensitizing drug is followed by the irradiation of light. Activated photosensitizers transfer energy to molecular oxygen which results in the generation of reactive oxygen species which in turn cause cells apoptosis or necrosis. Although this modality has significantly improved the quality of life and survival time for many cancer patients it still offers significant potential for further improvement. In addition to the development of new PDT drugs, the use of nanosized carriers for photosensitizers is a promising approach which might improve the efficiency of photodynamic activity and which can overcome many side effects associated with classic photodynamic therapy. This review aims at highlighting the different types of nanomedical approaches currently used in PDT and outlines future trends and limitations of nanodelivery of photosensitizers.     

Photodynamic therapy for treatment of infected burns

Burns are among the most debilitating and devastating forms of trauma. Such injuries are influenced by infections, causing increased morbidity, mortality, and healthcare costs. Due to the emergence of multidrug-resistant infectious agents, efficient treatment of infections in burns is a challenging issue. Antimicrobial photodynamic therapy (aPDT) is a promising approach to inactivate infectious agents, including multidrug-resistant. In this review, studies on PubMed were gathered, aiming to summarize the achievements regarding the applications of antimicrobial photodynamic therapy for the treatment of infected burns. A literature search was carried out for aPDT published reports assessment on bacterial, fungal, and viral infections in burns. The collected data suggest that aPDT could be a promising new approach against multidrug-resistant infectious agents. However, despite important results being obtained against bacteria, experimental and clinical studies are necessary yet on the effectiveness of aPDT against fungal and viral infections in burns, which could reduce morbidity and mortality of burned patients, mainly those infected by multidrug-resistant strains.     

Photodynamic therapy for tracheal thyroid metastasis

We report the case of a patient with recurrence of follicular carcinoma of the thyroid 8 years after surgical resection followed by external beam radiotherapy and radio-iodine treatment. The patient was treated by endoscopic photodynamic therapy (PDT) with complete endoscopic response after 12 months with good symptom relief.     

Photodynamic therapy enhances the cytotoxicity of temozolomide against glioblastoma via reprogramming anaerobic glycolysis

The successful application of photodynamic therapy in the treatment of glioma (CNS WHO grade 4) depends in large part to the effect of killing cells in the infiltrating area after tumor had been removed, when combined with radiotherapy, chemotherapy, and targeted drug therapy. The purpose of this study was to investigate the potential mechanism of TMZ's involvement in the glioma's glycolytic metabolic pathway during photodynamic therapy. The low dose of photodynamic therapy treatment on the cell viability of gliomas was investigated by CCK8. Alterations in reactive oxygen species were detected by flow cytometer. The differentially expressed proteins related to glucose transporter 1 (GLUT-1), matrix metalloproteinase-2 (MMP-2)/actively MMP-2 and apoptosis-associated caspase-3/cleaved caspase-3 were evaluated by Western Blot experiment. Additionally, transmission electron microscopy observed apoptosis, necrosis and the changes of the ultrastructure in U251 cells. In addition, antitumor effects in vivo were tested using orthotopic BALB/c mice with the glioma U87 model. The findings showed that low dose PDT affected mitochondrial function by inducing radical oxygen, hindered cellular glucose transport and metabolism, and induced apoptosis. The results also showed that cell viability considerably decreased and increased cell apoptosis under the PDT therapy. The HIF-1/GLUT-1 axis enhanced the cytotoxicity of temozolomide in gliomas as a result of PDT treatment, which was influenced by ROS. As a result, this study presents PDT as a potential therapeutic approach for treating malignant glioma, and enhanced antitumor effect of TMZ by inhibiting glycolytic pathway.     

Photodynamic therapy to control microbial biofilms

Microorganisms thrive in well-organized biofilm ecosystems. Biofilm-associated cells typically show increased resistance to antibiotics and contribute significantly to treatment failure. This has prompted investigations aimed at developing advanced and novel antimicrobial approaches that could effectively overcome the shortcomings associated with conventional antibiotic therapy. Studies are ongoing to develop effective curative strategies ranging from the use of peptides, small molecules, nanoparticles to bacteriophages, sonic waves, and light energy targeting various structural and physiological aspects of biofilms. In photodynamic therapy, a light source of a specific wavelength is used to irradiate non-toxic photosensitizers such as tetrapyrroles, synthetic dyes or, naturally occurring compounds to generate reactive oxygen species that can exert a lethal effect on the microbe especially by disrupting the biofilm. The photosensitizer preferentially binds to and accumulates in the microbial cells without causing any damage to the host tissue. Currently, photodynamic therapy is increasingly being used for the treatment of oral caries and dental plaque, chronic wound infections, infected diabetic foot ulcers, cystic fibrosis, chronic sinusitis, implant device-associated infections, etc. This approach is recognized as safe, as it is non-toxic and minimally invasive, making it a reliable, realistic, and promising therapeutic strategy for reducing the microbial burden and biofilm formation in chronic infections. In this review article, we discuss the current and future potential strategies of utilizing photodynamic therapy to extend our ability to impede and eliminate biofilms in various medical conditions.     

Photodynamic therapy for treatment of bacterial keratitis

Microbial keratitis is the main cause of corneal opacification and the fourth leading cause of blindness worldwide, with bacteria the major infectious agent. Recently, bacterial keratitis has become a serious threat due to routine use of antibiotics leading to selection of resistant and multidrug-resistant bacteria strains. New approaches for treatment of bacterial keratitis are necessary to outcome the increasing antibiotic resistance. Antimicrobial photodynamic therapy is based on three agents: photosensitizer, oxygen, and light radiation. This therapy has been successful for treatment of infections in different tissues and organs as well as against different type of infectious agents and no resistance development. Also, new photosensitizers are being developed that has increased the spectrum of therapeutic protocols for treatment of a number of infectious diseases. Thus, antimicrobial photodynamic therapy has an extraordinary potential for treatment of those bacterial keratitis cases that actually are not solved by traditional antibiotic therapy.