非侵入性激光照射可以诱导细胞和组织的光生物调节效应。光生物调节(PBM)应用广泛, 特别是在抗微生物感染和改善炎症方面有着很好的效果。然而, 研究发现, PBM对细菌和炎症有双向调节现象, 抗菌-促菌和抑炎-促炎在不同的试验条件下会发生变化。近些年来, PBM的临床应用受到越来越多的关注, 特别是在抗菌领域, 因为它是一种无创的策略, 禁忌症少。然而, 由于双向调节效应, 研究人员仍然对PBM的应用方式存疑, 必须根据其临床应用进行光照波长、剂量等参数的修改。因此, 本文总结了PBM对细菌的双向调节效应, 分析了这种双向调节效应产生的影响因素及其分子机制。PBM对细菌的双向调节作用受光照波长、剂量、细菌类别及细菌状态的影响。更好地了解低强度激光治疗中双向剂量反应的程度能够探索PBM使用的最可靠机制, 并最终使各种疾病患者的治疗标准化, 这对于优化临床治疗是必要的。此外, 研究人员对PBM双向调节机制的合理利用使其可以达到促进或抑制细菌生长的作用, 这在微生物制造、菌群调节、改善和治疗疾病等领域有广阔的应用前景。

细菌是人类最常见的致病源之一，不仅严重危害人类健康和公共卫生安全，还带来了巨额的医疗支出。快速而准确的细菌检测对细菌感染的治疗具有重要的意义。光谱检测方法不但可以快速实时地获得细菌的分类、含量以及功能状态等信息，而且具有操作简单、非侵入性的优势，在细菌检测领域具有巨大的潜力。本文介绍了拉曼光谱、太赫兹光谱、可见光和近红外光光谱、荧光光谱在细菌检测方面的研究与应用，并对可见光和近红外光光谱的分子机制——光靶点，包括含有视网膜发色团的细菌视紫红质（ CBCRs）、带有四吡咯发色团的拟菌植物色素、带有对香豆酸发色团的光活性黄蛋白（ PYP）、带有黄素单核苷酸（ FMN）的光氧压力（ LOV）结构域、带有黄素腺嘌呤二核苷酸（ FAD）发色团的隐色剂和含有 FAD的蓝光感应域等进行了阐述。最后，针对现有细菌光谱检测技术的优缺点提出了细菌检测技术的优化策略，希望对细菌的光谱检测研究提供帮助。

Periodontitis is closely related to many systemic diseases linked by different periodontal pathogens. To unravel the relationship between periodontitis and systemic diseases, it is very important to correctly discriminate major periodontal pathogens. To realize convenient, e±cient, and high-accuracy bacterial species classification, the authors use Raman spectroscopy combined with machine learning algorithms to distinguish three major periodontal pathogens Porphyromonas gingivalis (Pg), Fusobacterium nucleatum (Fn), and Aggregatibacter actinomycetemcomitans (Aa). The result shows that this novel method can successfully discriminate the three abovementioned periodontal pathogens. Moreover, the classification accuracies for the three categories of the original data were 94.7% at the sample level and 93.9% at the spectrum level by the machine learning algorithm extra trees. This study provides a fast, simple, and accurate method which is very beneficial to differentiate periodontal pathogens.

光学参数如波长、功率密度、照射时间等可显著影响光疗的杀菌效果。本研究旨在探索LED光疗抑制口腔细菌增殖的最佳光学参数, 为临床口腔细菌感染性疾病的光学治疗提供参考。将粪肠球菌(Enterococcus faecalis)和牙龈卟啉单胞菌(Porphyromonas gingivalis)菌液接种于96孔板中, 用峰值波长为405 nm和455 nm的自制LED光源, 以10 mW/cm2和40 mW/cm2的功率密度, 在能量密度9.6～33.6 J/cm2的范围内对其进行光照, 30?min后以活死菌荧光染色或平板涂布法检测光疗杀菌效果。结果发现: 405/455 nm波长LED光照对两种厌氧菌均有显著的杀伤效果; 牙龈卟啉单胞菌在波长为405 nm、功率密度为40 mW/cm2、光照能量为33.6 J/cm2的LED光照下达最大抑菌率(96.05±1.80)%; 粪肠球菌则在波长为405 nm、功率密度为10 mW/cm2、光照能量为33.6 J/cm2时达到最佳抑菌效果(97.64±2.31)%。研究表明, 适宜的光学参数可使LED光照对口腔常见致病菌产生显著的抑菌效果。在本研究条件下, 波长为405 nm、照射剂量为33.6 J/cm2的参数组合效果最佳。

光动力疗法是目前临床上出现的一种新型治疗肿瘤的方法, 利用光敏剂吸收可见-近红外光并在组织氧的参与下发生光化学反应, 产生活性氧物质进而诱导肿瘤细胞凋亡或坏死。光动力疗法对肿瘤侵袭性低, 具有较高的选择性和良好的患者依从性, 因此被广泛用于各种消化道恶性肿瘤的姑息性治疗和挽救性治疗。本文对近年来国内外应用光动力疗法治疗消化道肿瘤的文献进行综述, 对所报道的疾病类型、治疗病例数、光敏剂和光源、疗效和安全性等信息进行分类整理, 并对所面临的挑战和近期的研究进展进行了汇总, 以期全面和客观地了解光动力疗法在治疗消化道肿瘤中的应用和研究进展, 探讨目前的新应用及存在的问题和可能的发展方向。

The main objective of this study is to evaluate the antibacterial effect of antibacterial photodynamic therapy (aPDT) on Streptococcus mutans (S. mutans) biofilm model in vitro. The selection of photosensitizers is the key step for the efficacy of photodynamic therapy (PDT). However, no studies have been conducted in the oral field to compare the functional characteristics and application effects of PDT mediated by various photosensitizers. In this research, the antibacterial effect of Methylene blue (MB)/650 nm laser and Hematoporphyrin monomethyl ether (HMME)/532 nm laser on S. mutans biofilm was compared under different energy densities to provide experimental reference for the clinical application of the two PDT. The yield of lactic acid was analyzed by Colony forming unit (CFU) and spectrophotometry, and the complete biofilm activity was measured by Confocal Laser Scanning Microscopy (CLSM) to evaluate the bactericidal effect on each group. Based on the results of CFU, the bacterial colonies formed by 30.4 J/cm² 532 nm MB-aPDT group and 30.4 J/cm² 532 nm HMME-aPDT group were significantly less than those in other groups, and the bacterial colonies in HMME-aPDT group were less than those in HMME-aPDT group. Lactic acid production in all treatment groups except the photosensitizer group was statistically lower than that in the normal saline control group. The activity of bacterial plaque biofilm was significantly decreased in the two groups treated with 30.4 J/cm² aPDT. Therefore, aPDT suitable for energy measurement can kill S. mutans plaque biofilm, and MB-aPDT is better than HMME-aPDT.

发光二极管(LED)是一种具有一定带宽的非相干光源,LED光源生物学效应的发现促进了其在生物医学领域的应用。基于不同波长LED光源照射组织深度的差别,分别介绍了各个波段LED光源的靶组织特异性及生物学效应,梳理了每个波段LED光源在临床优势病种中的应用现状,并对LED光源在生物医学领域的应用进行了展望,可为指导临床应用及仪器研发提供参考。

间充质干细胞(mesenchymal stem cells, MSCs)具有自我更新和多向分化的潜能, 但分化方向缺乏引导性, 受基因、细胞因子、内环境等多种因素的影响。干细胞移植是神经性疾病治疗的常用手段, 本文就MSCs定向神经分化的诱导方法如神经营养因子、化学诱导剂、光生物调节、中药诱导等及其可能机制进行阐述。