Novel Photothermal Agent For Synergistic Photothermal Therapy Of Cancer

As a novel cancer therapeutic method with merits of non-invasive and lower side effect,photothermal therapy had received widely attention.The mechanism of PTT was that NIR laser could create hyperthermal to ablate cancer cell.Traditional inorganic photothermal agents exhibited high light-heat conversion but had the fear of nonbiodegradable and long-term toxicity;Organic molecular of near infrared dyes was biodegradable,but photobleaching of them impeded PTT.Recent studies proposed that cancer cells were able to generate heat shocked proteins for surviving from PTT.Thus,development of novel,biosafety and biodegradable PTT agent with higher light-heat conversion and improving cellular thermosensitive ability was a promising cancer therapeutic method.This dissertation contented:1)DC/DLM@PPy nanoparticles was synthesized by oil in water emulsions based on optimal light-heat conversion and biocompatibility of PPy.Depending on the EPR effect,nanoparticles could assemble in cancer.After NIR irradiation,phase change materials would transform into gas from solid to bubbles.These bubbles significantly enhanced ultrasound imaging.At the same time,small molecular inhibitors would synergistically release into cancer cell for improving the thermosensitive of cancer and enhanced photothermal therapy.2)During our researches of PPy nanoparticles,the problem was that oversized nanoparticles were difficult to transport and eliminate in vivo.Thus,we also developed ultrasmall POM nanoparticles which were stored as freeze-dried powder in a mild method.POM nanoparticles acquired excellent biosafety and higher light-heat conversion.Experiments had proved the toxicity of POM toward cancer in vitro,and different tissue slices demonstrated that POM didn't induce apoptosis of normal cell,which proved the biosafety of POM.Analysis of tungsten element in blood and urine proved the renal metabolism of POM,which showed lower long-term toxicity of POM.Excellent peroxide scavenging ability allows it to reduce systemic inflammation.Taken all together,the prepared ultrasmall POM nanoparticles had a huge potential and foreseeable application in photothermal therapy.