Phototherapies-based Nanomaterials For Cancer Treatment

Cancer has been one of the major threats to the lives of human beings currently.Phototherapies have become one of the emerging methods of cancer treatment.With the development of nanomaterials and nanotechnology,phototherapies,such as photodynamic therapy?PDT?,photothermal therapy?PTT?and combinational PTT and PDT therapies,have been developing rapidly.Besides,hypoxia,defined as inadequate oxygen supply at tissue level,is a common pathological condition in tumor microenvironment of certain solid tumors,leading to one of the barriers of the tumor treatment.In addition,although phototherapy has the advantage of small wounds,it can also cause the certain degree of the damage to the tissue.Therefore,we prepared two nanomaterials based on phototherapies of cancer in order to solve the problem of the hypoxia of soild tumor as well as the wound healing after the phototherapies.Firstly,to overcome the problem of the hypoxia of soild tumor,tumor-targeting oxygen self-carrying nanoparticles were developed for photothermal therapy?PTT?and enhanced PDT to completely eradicate solid tumors.Hydrogen peroxide?H₂O₂?is a strong oxidant that can release oxygen with the presence of a catalyst or being heated.The core-shell poly?lactic-co-glycolic acid?nanoparticles?PLGA NPs?are obtained by a double emulsion method:hydrophilic H₂O₂/poly?vinylpyrrolidone?complex as an oxygen source and hydrophobic IR780 as a PTT/PDT agent are encapsulated into the core and shell of the NPs respectively.Tumor binding molecule,folic acid,is conjugated onto the surface of obtained PLGA NPs to enabling efficient cell uptake and tumor targeting.Once PLGA-FA/IR780-H₂O₂ NPs are ingested by HepG2 cells,it can induce photothermal effect and reactive oxygen species?ROS?release to kill cancer cells under an 808 nm laser irradiation.The encapsulated H₂O₂can supply additional oxygen and in turn significantly enhance the PDT effect.This innovative nanoplatform has exhibited excellent antitumor efficiency,verified vividly by in vitro and in vivo assay,and may serve as a versatile platform for future cancer therapy.Secondly,in order to explore the bifunctional properties of phototherapies-based nanomaterials for cancer treatment and stimultaneously for stimulating wound healing,a hydrogel composited of gold nanorods and gelatin were prepared for PTT and wound healing.Gold nanorods can be employed for photo-thermal cancer owing to its excellent photo-thermal conversion.In addition,gelatin,the nature polymer,possesses good bio-compatibility.The homogenous mixture composited of gelatin and gold nanorods which modified by polyethylene glycol by the method of ligand exchange and crosslinked with the glutaraldehyde at a final concentration of 0.25%.Gelatin-AuNR@PEG hydrogels exhibited good mechanical properties and excellent photo-thermal conversion as well as favorable bio-compatibility.What'ts more,the cytotoxicity results showed that gelatin-AuNR@PEG hydrogels exhibited very low toxicity towards 4T1 cells.Also,it exihibited good bio-compatibility.The apoptosis experiments showed that gelatin-AuNR@PEG hydrogels inhibited tumor growth attributing to PTT under a 808 nm laser irradiation?0.4 W/cm²,2 min?in vitro.