光功能化上转换纳米粒子的控制合成及其在牙周光动力抑菌治疗中应用的基础研究

牙周炎传统疗法是机械治疗辅助药物治疗，由于诊疗器械难以探及结构复杂部位以及易产生细菌耐药性，传统疗法无法取得良好的治疗效果。抗菌光动力疗法是光敏剂和特定波长激光间的非热能光化学反应，可以诱导细菌失活，细菌内源性光敏剂能够吸收激发光的能量使其自身活化实现光动力治疗，避免外源光敏剂的细胞毒性问题，该方法为牙周炎的治疗提供了新思路。光能转化纳米材料和光动力内源性抑菌治疗相结合为牙周炎临床治疗提供了新的研究思路。本项目拟控制合成光功能化上转换纳米粒子NaYF4:Yb/Nd/Tm@NaYF4:Nd，使其在穿透深度较深的近红外光激发下发射蓝光，有效激活牙周主要致病菌牙龈卟啉单胞菌的内源性卟啉，产生活性氧，破坏菌体内DNA链，达到抑菌效果。利用静电纺丝将上转换纳米材料与聚己内酯复合，为上转换纳米材料提供支架便于植入到牙周炎患病部位，最终构建一种近红外光激发实现光能转换的支架材料，为牙周病治疗开辟新方向。

The traditional treatment of periodontitis is mechanical therapy assisted by drug therapy. Due to the difficulty in probing the complex parts of the root bifurcation and prone to bacterial drug resistance, the traditional therapy cannot achieve good therapeutic effects. Antimicrobial photodynamic therapy, a non-thermal photochemical reaction between a photosensitizer and a specific wavelength laser, provides a new idea for clinical treatment of periodontitis. This treatment can induce bacterial inactivation and the bacterial endogenous photosensitizers can avoid the cytotoxicity of exogenous photosensitizers by absorbing the energy of excitation light and activate themselves to achieve photodynamic therapy. The combination of photoenergy conversion nanomaterials and photodynamic endogenous antimicrobial therapy provides a new research approach for clinical treatment of periodontitis. In this projects, we focus on the controlled synthesis of functionalized upconvertion nanoparticles NaYF4:Yb/Nd/Tm@NaYF4:Nd, which can emmit blue light excited by near-infraed light and motivate endogenous porphyrins of porphyromonas gingivalis to produce reaction oxygen species, destroy bacterial DNA, achieve antibacterial effect. The scaffold was synthesized by upconversion nanomaterials and polycaprolactone via electrostatic spinning to easy to implant into the affected area of periodontitis. In the end, a kind of scaffold material excited by near-infrared light to realize the conversion of light energy is constructed, which opens up a new direction for the treatment of periodontal disease.