| Cancer diagnosis and therapy are always independent process in clinic application,thus,patients must be clearly diagnosed with using imaging agents before therapy with therapeutic agents.While repeated drug usages are easily to cause combined side effects that added pains and secondary risks to patients.Therefore,we designed novel theranostic nano-platform for solving these problems mentioned above,which have realized to combine tri-modal imaging with treatment means organically on the one hand,on the other combine chemotherapy with other therapy modes in a synergistic manner so as to decrease dosage toxicity of chemotherapeutic agents and strengthen therapeutic effectsBased on the issues such as difficulties to effective deliver hydrophobic drugs to tumor,inherent drawbacks or single function of current carriers studied,we synthesized a stable,high-efficient and multifunctional nanocarrier of Cys-Fe3O4/CuS@BSA,with raw materials that compatible or approved by FDA,via a facile method,in chapter 2.The inner space of carrier could load hydrophobic drugs.In the paper,PTX was employed as a drug model.Measured by HPLC,results showed that the encapsulation rate was 97.3%,the loading efficiency was 6.6%.In the meantime,PTX released from the nanocarrier with pH sensitive and NIR light controlled property.In vitro and in vivo experiments revealed that,the nanocarrier was biocompatible.It could deliver drugs targetedly to tumor sites by magnetic field,and transferred NIR laser into heat for inducing photothermal therapy.Then the existing heat could not only kill cancer cells,but also promote the release of PTX from carrier for chemotherapy.The synergistic effect of combining chemotherapy with photothermal therapy(PTT)is capable of totally tumor elimination,much better than only chemotherapy or PTTWhile,considering that nano-carriers synthesized by several meterials may results unstable within some media in the long-term,and present triple-modal imaging and tri-modal combination therapy become overwhelming and popular,a facile solvent-thermal method was adopted to prepare a multifunctional theranostic nano-agent of Bi-MSx-PEG,which integrate several functions into one component in chapter 3.The agent have totally realized tri-modal tumor imaging-guided tri-modal therapy.Such as containing magnetic resonance imaging(MRI),computed tomography(CT)imaging and photoacoustic(PA)imaging,PTT,phodynamic therapy(PDT),chemotherapy.PEG was employed for increasing the compatibility and stability of Bi-MSx in physiological media.The nanoagent possess special flower-like structure and appropriate particle size,that adapted to deliver drugs,and its DOX loading efficiency reached as high as 90.0%.In addition,the agent could induce photothermal therapy and phodynamic therapy upon NIR light irradiation,and its photothermal-conversion efficiency reached as high as 40.7%.In vivo experiment demonstrated that,the tumors of HeLa tumor-bearing mice could be erased clearly,without regeneration and regrowth.In conclusion,these novel multifunctional nanoparticles which were first synthesized in the paper,were characterized with simple preparation,rational structure and excellent performance in cancer diagnosis and therapy It could realize in vivo combination therapy due to the synergy of tri-modal therapeutic modes,and then lead strong killing effects to cancer cells as wellIn the paper,multi-functional nano-platforms were created via a facile manner,realizing integrate diagnose and treatment into one agent,conducting a more thorough study in application of tumor tri-modal imaing and therapy,and laying the foundation for the application of using a novel theranostic nanoagent in biomedical area. |
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