The Construction Of A New Type Of Oxygenated Nano Photosensitizer And The Photodynamic Therapy Effect Of Oral Squamous Cell Carcinoma

Objective:Photodynamic Therapy?PDT?is a kind of biological response involved in oxygen molecules,recently it has been widely used in the clinical treatment ofsuperficial oral cancer.But the absorbance of photosensitizer in tumor and the oxygen dependence limits the efficacy of PDT,therefore it is important to improve theabsorption of photosensitizer and change the condition of hypoxia.In this study weproposed to design and synthesis a new type of photosensitizer nanoparticle Catalase@Chitosan-Ce6 which can both improve the absorption and increase oxygenconcerntration to improve the effect of PDT.Method:We made a new type of nano photosensitizer with the method ofelectrostatic adsorption,improving its dispersibility and compatibility,increasing the selectivity of photosensitizer and passive targeting;Secondly through these smallmolecular hydrogen peroxide enzyme,negatively charged Catalase can reaction with H₂O₂ in tumor tissue and continue to produce oxygen,inhibiting tumor from hyproxia,achieving dual role of targeted in cancer and increasing oxygen.We use oral squamous cancer cells model?tumor bearing mice?to verify the effect of increasing oxygen andphotodynamic effect;Through the body model validation on the target's ability to absorb and regulation of hypoxia and apoptotic pathways.Results:Successfully constructed with the method of static adsorption in the tumor hypoxia environment has the role of increasing oxygen nano photosensitizer?Catalase@Chitosan-Ce6?and a series of characterization,to verify the stability and the properties of the nanoparticles.Through the normal cells L929 cell line,tumor cells and Hela CAL-27 cell lines in vitro,verified the nano photosensitizer Catalase@Chitosan-Ce6 dark toxicity is low,is a safe,photosensitizer,tumor cells and can be selectively absorb,taking part in the cytoplasm;And through the determination of Reactive Oxygen Species?ROS?to verify the yield ratio of Catalase@Chitosan-Ce6 in tumor in theenvironment of lack of oxygen aerobic capacity.Catalase@Chitosan-Ce6 photodynamic therapy on oral squamous cell carcinomas CAL-27 cells dynamics of light higher than free Ce6,induced tumor cell apoptosis rates are higher,and can be activated Caspase-3,to start the apoptosis pathway,verify thehigh expression of apoptosis protein Caspase 3and Cleaved Caspase 3,lower expression of hypoxia related proteins HIF-1a.There are inhibition of oxygen pathway.By Dutch CAL-27 tumor of nude mice we found thatCatalase@Chitosan-Ce6 in vivo distribution has the characteristics of clustered in tumor targeting,and its mediated PDT treatment CAL-27 oral squamous cell carcinomas solid tumor free Ce6 effect is better,and not accompanied by systemic side effects.Conclusion:?1?Successfully constructed by using the method of static adsorption in the tumor hypoxia environment has the role of increasing oxygen nanophotosensitizer?Catalase@Chitosan-Ce6?and a series of characterization,to verify the stability and the properties of the nanoparticles.?2?Based on normal cells L929 cell line,cancer cells Hela and CAL-27 cell lines in vitro experiment,verified the nano photosensitizer Catalase@Chitosan-Ce6 darktoxicity is low,is a safe means of photosensitizer,tumor cells and can be selectivelyabsorbed,taking part in the cytoplasm;And through the determination of singlet oxygen,ROS production rate of the Catalase@Chitosan-Ce6 indeed in the tumor environment of lack of oxygen aerobic capacity.?3?Catalase@Chitosan-Ce6 photodynamic therapy of oral squamous cellcarcinomas CAL-27 cells dynamics of light higher than free Ce6,induced tumor cell apoptosis rates are higher,and can be activated Caspase-3,to start the apoptosispathway,and after photodynamic treatment also verified the apoptosis protein Caspase 3,Cleaved Caspase 3 high expression of hypoxia related proteins HIF-1 a lowerexpression.Illustrate by inhibition of oxygen pathway.?4?In vivo study of nano photosensitizer Catalase@Chitosan-Ce6 in vivo distribution has the characteristics of clustered in tumor targeting,and CCCe6mediated PDT effect inCAL-27 oral squamous cell carcinomas is better than free Ce6and not accompanied with systemic side effects.