Sanchez-Barcelo Emilio J, Mediavilla Maria D
Department of Physiology and Pharmacology,School of Medicine,University of Cantabria, 39011 Santander, Spain.
Recent Pat Endocr Metab Immune Drug Discov. 2014 Jan;8(1):1-8. doi: 10.2174/1872214807666131229103707.
This article reviews the more recent patents in three kinds of therapeutic strategies using the application of visible light to irradiate photosensible substances (PSs) of different natures. The light-activation of these PSs is directly responsible for the desired therapeutic effects. This group of light therapies includes photodynamic therapy (PDT), photothermal therapy (PTT) and photoimmunotherapy (PIT). Therapeutic mechanisms triggered by the activation of the PSs depend basically (though not exclusively) on the release of reactive oxygen species (ROS) and the activation of immune responses (PDT and PIT) or the local generation of heat (PTT). The main difference between PIT and PDT is that in PIT, monoclonal antibodies (MABs) are associated to PSs to improve the selective binding of the PSs to the target tissues. All these therapeutic strategies offer the possibility of destroying tumor tissue without damaging the surrounding healthy tissue, which is not achievable with chemotherapy or radiotherapy. PDT is also used as an alternative or adjuvant antimicrobial therapy together with the traditional antibiotic therapy since these organisms are unlikely to develop resistance to the ROS induced by PDT. Furthermore, PDT also induces an immune response against bacterial pathogens. The current challenge in PDT, PIT and PTT is to obtain the highest level of selectivity to act on targeted sick tissues with the minimum effects on the surrounding healthy tissue. The development of new PSs with high affinity for specific tissues, new PSs- MABs conjugates to bind to specific kinds of tumors, and new light-sensible nanoparticles with low toxicity, will increase the clinical utility of these therapies.
本文综述了三种治疗策略中较新的专利，这些策略利用可见光照射不同性质的光敏物质（PSs）。这些PSs的光激活直接导致了预期的治疗效果。这组光疗法包括光动力疗法（PDT）、光热疗法（PTT）和光免疫疗法（PIT）。PSs激活引发的治疗机制基本上（尽管并非唯一地）取决于活性氧（ROS）的释放以及免疫反应的激活（PDT和PIT）或局部产热（PTT）。PIT和PDT的主要区别在于，在PIT中，单克隆抗体（MABs）与PSs结合，以提高PSs与靶组织的选择性结合。所有这些治疗策略都提供了在不损害周围健康组织的情况下破坏肿瘤组织的可能性，而这是化疗或放疗无法实现的。PDT还与传统抗生素疗法一起用作替代或辅助抗菌疗法，因为这些微生物不太可能对PDT诱导的ROS产生耐药性。此外，PDT还能诱导针对细菌病原体的免疫反应。PDT、PIT和PTT目前面临的挑战是获得最高水平的选择性，以便作用于靶向患病组织，同时对周围健康组织产生最小影响。开发对特定组织具有高亲和力的新型PSs、与特定类型肿瘤结合的新型PSs-MABs偶联物以及低毒性的新型光敏纳米颗粒，将增加这些疗法的临床实用性。
