纳米技术用于肿瘤光动力治疗

【作者】 李磊；

【导师】 陈暨耀；

【作者基本信息】 复旦大学 ， 光学， 2011， 硕士

【摘要】 1996年,伴随着第一代PDT药物Photofrin的获准,肿瘤光动力疗法作为现代肿瘤新疗法,被美国FDA批准应用于临床：并在美国、日本、英国、法国、德国、加拿大等国用于多种肿瘤治疗取得成功。2003年5月中国SFDA批准了这一治疗系统进入临床应用。随着生物医学研究的发展,对新一代PDT药物的研究展现出越来越多的必要性。近年来,随着纳米技术的飞速发展,纳米材料以其优越的性能必然为生物医学带来一场技术革命。水溶性半导体荧光量子点由于其良好的光学特性,如高量子效率、尺寸可调的荧光发射波长、宽带吸收与窄带荧光、可调节的表面电荷、光稳定性良好,双光子吸收截面大等,被认为是非常重要的一种荧光标记材料,并且广泛地应用于细胞标记技术、蛋白示踪、DNA阵列检测技术、免疫荧光标记方法、生活活体及组织检测等方向的研究。纳米金颗粒以其良好的水溶性、完全的无毒性质、随尺寸调节的荧光发射及吸收带宽、光稳定性和双光子吸收；近年来越来越多的应用于生物医学领域,如作为生物探针,药物载体和赋型剂等等。本文将传统的PDT光敏剂铝钛箐,与现今在生物医学领域广泛应用的CdSe量子点及金纳米杆相结合；试图运用纳米颗粒的良好性质在寻找新一代的PDT药物方向上找到新的道路。主要有以下的结果：成功的将酞箐与DHLA包裹的表面带正电的CdSe量子点相连接,并且通过荧光,Zeta电势,TCSPC技术进行了水溶液中连接验证；CdSe量子点成功的将酞箐运载进入细胞,速度远快于游离酞箐：量子点与酞箐在细胞内稳定的连接通过荧光和TCSPC技术分别得到了证明。实现了量子点与酞箐间的能量共振转移,大大加强了酞箐在可见光区域的受激效果。通过平均寿命计算出能量转移效率达到80%。最后MTT效果显示,与量子点的连接大大增强了酞箐的PDT效果。成功的将酞箐与金纳米杆相连接,并通过过滤的方法计算出金纳米杆与酞箐的最佳连接比例为1：1×104。与金纳米杆成功的连接明显增进了酞箐进入细胞的能力,通过表面等离子体共振增强的荧光能力及PDT效果。并且在800fs激光的帮助下,实现了金纳米杆与酞箐聚合物在细胞内的酞箐药物卸载。更多还原

【Abstract】 The sulfonated aluminium phthalocyanines (AlPcSs), commonly used photosensitizers (PSs) for photodynamic therapy of cancers (PDT), were conjugated to amine-dihydrolipoic acid coated quantum dots (QDs) by the electrostatic binding with the linkage of about 70 AlPcSs per QD. The AlPcS-QD conjugates can utilize the high light absorption coefficients of QDs to indirectly excite AlPcSs producing singlet oxygen via fluorescence resonance energy transfer (FRET), suggesting a new excitation model for PDT. The AlPcS-QD conjugates easily penetrated into KB cancer cells and performed the FRET with the efficiency of about 80% in cells. Under the irradiation of a 532 nm laser, which is at the absorption region of QDs but not fitted to the absorption band of AlPcSs, the cellular AlPcS-QD conjugates can destroy the most cancer cells via FRET mediated PDT, demonstrating the potential of this new strategy.Hexadecyl trimethyl ammonium bromide coated gold nanorods (AuNRs) with positive charges were effectively bound to negatively charged suifonated aluminium phthalocyanine (AlPcS), a photosensitizer for photodynamic detection and therapy, due to the electrostatic force, with a loading content of 104 AlPcS molecules per rod. A five-fold increase in the AlPcS fluorescence of the AlPcS-AuNRs complex was seen. The excitation fluorescence spectrum of the AlPcS-AuNRs with a typical 520 nm band fits well with the resonance band of AuNR surface plasmons, suggesting that such increased AlPcS fluorescence is produced from the strong surface plasmons of AuNRs. The intracellular distribution of AlPcS-AuNRs was studied in the QGY liver cancer cells by respectively imaging the AlPcS fluorescence and AuNRs reflectance with a confocal microscope. Furthermore, the AlPcS-AuNRs-loaded cells were photodynamically damaged after being exposed to red light in a light-dose dependent manner. In contrast, no phototoxicity of the cells was seen after incubation with the same amount of free AlPcS, indicating that the AlPcS-AuNRs can enhance the AlPcS-mediated photodynamic effect. In addition, the loaded AlPcS can be photothermally released from AuNRs in the cells by the irradiation of an 800 nm femto-second laser, demonstrating the potential for a controlled drug release.更多还原