【作者】 盛艳秋；

【导师】 张治国；

【作者基本信息】 哈尔滨工业大学 ， 光学， 2006， 硕士

【摘要】 光动力疗法是利用光动力反应进行诊断和治疗的一种新技术,具有创伤小、毒性低、选择性好等突出优点。然而,目前光动力疗法存在二个不足之处:一是光敏剂的审批困难;二是没有荧光诊断指导。本论文的研究内容是围绕光敏剂辐射性质研究和自体荧光诊断技术进行的。研究目的是把临床使用的药物发展成新的光敏剂,从而避免光敏剂审批问题;此外是对牙结石的自体荧光诊断技术的研究,对有效治疗牙周病具有重要意义。利用能级跃迁理论分析了三能级系统的光敏剂分子,建立了各能级的粒子数随时间衰变的关系;对罗丹明123进行了光谱性质的研究,包括吸收光谱、荧光光谱以及不同浓度和不同PH值条件对荧光光谱的影响;对罗丹明123荧光寿命测量的结果表明,罗丹明123的单重激发态寿命小于1ns;建立了测量敏化单态氧跃迁系统,结果发现罗丹明123没有产生敏化单态氧,说明其光动力效应的敏化产物不是单态氧,而是自由基。建立了一套荧光光谱点诊断系统,利用这套系统进行了牙结石的自体荧光诊断和药物荧光诊断的研究。实验表明,正常牙齿的荧光峰值在499nm,结石的荧光光谱中出现了峰值为635nm和690nm两个特征峰,从而确立了自体荧光诊断牙结石的方法;通过自体荧光诊断实验研究,证明荧光比率诊断方法具有最高的灵敏度,同时还能克服光的照射距离、输出功率、组织体表面方位角等外部探测条件对诊断的影响。选取罗丹明123作为光敏剂,进行了药物荧光诊断的研究。研究表明罗丹明123对正常牙面没有附着性;而罗丹明123会附着在结石的牙面上,因此利用罗丹明123在595nm处的特征荧光峰,可以对牙结石进行诊断;实验研究得出:面积比值P>1就是结石;P<1不是结石。从而为临床医生提供了一种科学地判断是否存在结石和结石是否清除干净的判据。更多还原

【Abstract】 Photodynamic as a new method has been used in diagnoses and therapy of tumors and some non-cancerous disease. It has a lot of outstanding advantages, such as small-wound, low-toxicity and high-selectivity. But photodynamic therapy has two shortages: it is very difficult to approve a new photosensitive medication; there is no director for fluorescent diagnosis. Our research is around optical properties of photosensitizer and autofluorescent diagnoses. The purpose of our research is using clinical medicine as photosensitizer in order to avoid the approval of the novel medicine. Furthermore, autofluorescence is used for spectral diagnoses of calculus, which has the important meaning to effectively treat the periodontal disease.Making use of energy level transition theories we analyze the three level energy system of a photosensitive molecule to build up decay traces of every energy level particle population. Absorption and fluorescence spectra of rhodamine123 and the influence of PH value were investigated. Time-resolved fluorescence spectroscopic measurements of rhodamine123 were carried out. The result indicates the lifetime of rhodamine123 is less than 1ns. The equipment of measuring singlet molecule oxygen produced by photosensitization was developed. The emission spectra from singlet molecule oxygen in the excited state photosensitized by rhodamine123 were not obtained on the equipment. This illustrates the product photosensitized by rhodamine123 is not singlet molecule oxygen, but free radical.A diagnose system was set up, then autofluorescence and sensitization fluorescence of calculus were measured. The measurement result indicates that no change was found between normal and calculus at 499nm, but two significant fluoresence peaks at 635nm and 690nm were found on the calculus. So autofluorescence can be used for spectral diagnoses of calculus.A great deal of research indicates rhodamine123 can selectively accumulate in the calculus, so fluorescence spectra of rhodamine123 can be used for photodynamic diagnoses of calculus. In conclusion, the ratio P<1 indicate no calculus, P>1 indicate calculus. Therefore, the present study will be benefic for更多还原