Preparation Of Polypyrrole-based Composites Nanomaterials And Their Application In Biomedical Field

Nowadays,the number of cancer patients have increased year by year with the changes in the environment and lifestyle.However,due to the limitations of chemotherapy,surgery and radiation therapy,the cure rate has been difficult to improve,so new cancer treatment technology has become the research direction of scholars.The photothermal therapy method with small wound surface,precise positioning,low biological toxicity,less adverse reactions and good clinical application prospects is favored by researchers.Therefore,the design of multifunctional nano-drugs(photothermal therapy,magnetic resonance imaging,CT imaging,drug-loading functions,etc.)has also rapidly become a research hotspot in the field of"biomaterials and nanomedicine".Based on the current research status,we have prepared nanocomposites for cancer diagnosis and treatment.The specific research contents are as follows:(1)Polypyrrole nanoparticles exhibited potential applications in biomedical applications due to low toxicity,photostability and good biostability.Therefore,we have assembled the new multifunctional PPy@Fe₃O₄/Au nanocomposites(Au,Fe₃O₄nanoparticle coated polypyrrole)by electrostatic adsorption method,and which were used to guide photothermal treatment of tumor cells by CT and MR imaging.Specifically,Fe³⁺acted as an oxidant to mediate the polymerization of pyrrole to form polypyrrole(PPy)nanoparticles.Then,an aqueous ammonia solution was added,and residual iron ions(Fe³⁺and Fe²⁺)formed Fe₃O₄ nanoparticles on the surface of the PPy nanoparticles.Finally,due to electrostatic interaction,Au and PPy@Fe₃O₄ nanoparticles were mixed to assemble PPy@Fe₃O₄/Au nanocomposites.Related experiments in vitro showed that the prepared PPy@Fe₃O₄/Au nanocomposites have good biocompatibility and excellent photothermal effect.In addition,excellent CT and MR imaging properties in vitro and in vivo indicated that PPy@Fe₃O₄/Au nanocomposites could be used for comprehensive diagnosis and precise guidance of tumor therapy.More importantly,the excellent photothermal effect of PPy@Fe₃O₄/Au nanocomposites could effectively inhibit tumors.In summary,the multifunctional PPy@Fe₃O₄/Au nanocomposites are prominently applied in the field of cancer treatment.(2)Based on the above research,we further prepared m PPy@Au/DOX nanocomposites with mesoporous structure,photothermal therapy,drug loading and CT imaging for synergistic therapeutic effects under targeted delivery.The details were as follows:the iron-doped mesoporous double-shell polypyrrole(m PPy)structure was synthesized by in-situ polymerization method,and the pyrrole monomer was filled to the shell surface and internal cavity of the porous Fe₃O₄ hollow microsphere under sonication.With the addition of HCl,Fe³⁺ions were gradually released from the outer and inner surfaces of the Fe₃O₄ shell,and then polypyrrole was repeatedly formed on both surfaces of the Fe₃O₄ shell until it completely dissolves to form mesoporous double-shell polypyrrole.The m PPy@Au/DOX nanocomposite was finally synthesized by electrostatic adsorption and loading.Experiments showed that the prepared nanomaterials can achieve the synergistic therapeutic effect of photothermal therapy and chemotherapy,and the tumor was well suppressed.In this paper,polypyrrole-based nanocomposites were constructed to combine CT imaging and photothermal therapy to integrate their advantages and disadvantages,which have a good application prospect in the field of tumor therapy.