Synergistic Cancer Therapy And In Vitro Detection Based On Silver Nano-materials

Due to its novel properties,metal ions have been applied to a broad range of nano biomedical fields such as sterilization,catalyzation,bio-markers and photoelectrical science Silver stands out of the crowd as it has great effect for sterilization.Some compounds of silver had been utilized as antibiotics for anti-infectious therapies before,especially for burn infections.However,there are still a lot of problems for the utilization of metallic silver,and to address these limitations,silver nano-materials were developed.By changing the size and shape of silver nanomaterials,the physical and chemical properties of these materials could be tailored to satisfy people's need.Recently,silver has attracted tramendous attention.Some of them utilized the oxidative stress of silver ions to kill cancer cells by the autophagy and damage of mitochondria.The degradability of silver also makes it prior to other inorganic materials.This thesis mainly includes the following three parts1.Degradable silver-based nanoplatform for synergistic cancer therapyTraditional cancer therapy usually has limited therapeutic effects and severe side effects Multi-model synergistic therapy is more effective than a single treatment modality.Therefore,we designed a silver-based nanomaterial consisted of silver nanocubes(AgNCs)and glucose oxidase(GOx)for green cancer synergistic therapy.The AgNC-GOx could catalyze the oxidation reaction of the intratumoral glucose,and generate H2O2 to dissolve AgNCs and produce silver ions.The toxicity of silver ions and H2O2,and the depletion of intratumoral glucose can achieve noninvasive,synergistic and green cancer therapy2.The construction and optimization of an activatable photothermal nanoagentPhotothermal therapy is distinguished from other cancer therapies due to its outstanding efficacy and negligible side effects.However,an activatable photothermal nanoagent had been barely reported before as far as we known.Hence,we designed a new photothermal nanoagent to achieve an activatable photothermal effect.Such a photothermal nanoagent is based on GNRs with silver coated on the surface to reduce or vanish its photothermal effect.Then we wrapped this silver coated GNRs with hollow SiO2 spheres and coupled GOx on the surface of the spheres to produce abundant H2O2 to etch the silver layers in presence of glucose.After the etching of silver layers,the photothermal effect of GNRs may recover,which achieves an activatable photothermal effect from "OFF" to "ON".3.Silver-coated gold nanorods(GNRs@Ag)for PA detection of glucoseSeveral noninvasive detection methods for glucose have been developed clinically.However,PA detection methods for glucose based on the "off" to "on" PA signals have been barely applied in glucose detections.Therefore,we designed and prepared a silver-coated gold nanorods(GNRs@Ag)and coupled GOx on its surface for the PA detection of glucose.Both the absorbance of 800 nm and the PA signal of gold nanorods disappeared,as a result of silver coating.The GOx on the surface can catalyze the glucose to generate H2O2 to dissolve the silver layer of GNRs@Ag,which hence causes the recovery of the PA signals.Therefore,the concentrations of glucose could be measured based on the PA signals.