Research On Neuropeptide Y Modified Nano Drug Delivery System In Targeted Treatment For Breast Cancer

Cancer has become a severe disease that threatens human health in recent years.Breast cancer is one of the most prevalent types of cancer in Chinese women,which seriously threatens women’s life.Traditional treatment like surgical,radiotherapy,and chemotherapy methods have limited ability to treat tumors that deep inside and tumor metastases,and have serious side effects,which urgently require safe and efficient new treatment methods.Targeted treatment is a new type of treatment.It is a treatment method that was born with the rising level of molecular biology technology.By selecting a protein molecule or a gene fragment that is highly expressed in tumor cells and low in normal tissues as targets,then designing drugs that specifically bind to the targets,so that the drugs are enriched only where the targets exist,or using nanocarriers that modified with the target molecule to carry the drugs,thereby achieving the goals of improving treatment efficiency and reducing side effects.Neuropeptide Y receptor is a type of receptor newly discovered on the surface of breast cancer.Normal cells express Y₂receptors,and breast cancer expresses Y₁ receptors.Therefore,neuropeptide Y polypeptide specific targets with high Y₁ specific affinity can be used.Nano drug delivery system is a generic term for materials that can be used for drug delivery and has nanometer size.The use of nanomaterials to deliver drugs has many advantages,such as protecting drugs in the blood environment,high-quality drugs loaded on the same mass,and the surface can be modified.With diagnostic and therapeutic functions,it is of great practical value to study highly targeted and low toxicity nano drug delivery systems.This article focuses on the buliding of a neuropeptide Y-modified nano drug delivery system for breast cancer targeted therapy.The main work is as follows:A nano drug delivery system AP-NM-DOX&Tar with passive enrichment,active targeting and pH response was constructed.The amphiphilic polymer Poly（lactic-co-glycolic acid）-Poly（ethylene glycol）（PEG-PLGA）was selected as the constituent material of the nanomicelles.The Neuropeptide Y analog AP-NPY and 1,2-distearoyl-sn-glycero-3-phosphoethanolamine-N-[methoxy（polyethylene glycol）-COOH（DSPE-PEG-COOH）was connected to obtain AP-PEG-DSPE polymer as a doping material..AP-NPY peptides were introduced on the surface of micelles.AP-PEG-DSPE-doped PEG-PLGA encapsulates the chemotherapeutic drug DOX and the inhibitor tarquinidine（Tar）to prepare dual drug-loaded nanomicelles.The micelle has a particle size of about 100 nm and a negative potential.It can passively targeted to the tumor area through the EPR effect.It has a long cycle time,is pH-responsive,and can release drugs in the tumor microenvironment.Human breast cancer MCF-7 cells and human multidrug-resistant breast cancer MCF-7/ADR cells were used as research models to qualitatively and quantitatively study the in vitro targeting and cytotoxicity of AP-NM-DOX&Tar nanomicelles.Qualitative and quantitative studies on the uptake of DOX by different types of nanomicelles using fluorescence confocal microscopy and flow cytometry.The effects of AP-NPY modification and P-glycoprotein inhibitor Tar,AP-NPY doping ratio,the amount of P-glycoprotein on the cell membrane surface,and the presence or absence of NPY receptors on the cell membrane surface were investigated.It was found that through the combined use of active targeting and efflux inhibition,the nano-drug delivery system can increase the drug concentration in multi-drug resistant breast cancer cells by three times and reduce the drug’s half inhibitory concentration to one fifth.The near-infrared dye IRDye780 was used to replace DOX to investigate the accumulation and distribution of AP-NPY modified nano-micelles carrying P-glycoprotein inhibitors in mice by in vivo fluorescence imaging of small animals.It was found that the drug accumulation in the tumor increased by approximately 38.1%after 6 hours of nanomicelle injection,and increased by 20%in the tumor after 24 hours of injection.The antitumor effect of AP-NM-DOX&Tar micelles was explored through the MCF-7/ADR tumor-bearing mouse model.The treatment results showed that the tumor volume shrank to 40%of the initial volume during 22 days of treatment,and the mouse survival time was extended to after treatment 55 days.Based on body weight changes,HE stained sections of major organs,and blood routine tests,nanomicelles have been shown to be safe in vivo.A zeolite-imidazole framework nano-drug delivery system modified with neuropeptide Y ligand modified red blood cell membrane with active targeting,dual response of pH and ATP,long circulation,and immune escape was constructed（NPY-RBC@ZIF-90@Ce6）.The drug delivery system consists of 2-formaldehyde imidazole（2-ICA）and zinc acetate self-assembled in solution to form ZIF-90 material,which is wrapped with photosensitizer chlorin e6（Ce6）to make ZIF-90@Ce6 material.Red blood cell membrane（RBC）was obtained by hypotonic swelling,and was doped with AP-PEG-DSPE,to form nano drug delivery system（NPY-RBC@ZIF-90@Ce6）.The particle size,potential,morphology,and drug content of the nano-drug delivery system were investigated;the use of UV spectrophotometer,infrared spectrometer,X-ray diffractometer,and specific surface area and porosity analyzer proved the formation of the ZIF-90 structure and Ce6 Onboard,in vitro drug release kinetics of nano-drug delivery systems was measured by fluorescence.The particle size of this nanomaterial is about 120nm and the surface has a negative potential.The Ce6 carried on it accounts for 5%of the total mass of the nanomaterial.With pH=5.0 and the presence of 0.5 m M ATP,NPY-RBC@ZIF-90@Ce6 can release more than 93%of Ce6 molecules within 24hours.Human breast cancer MCF-7 cells were used as the research model to quantitatively study the uptake of NPY-RBC@ZIF-90@Ce6 in MCF-7 cells by flow cytometry.MCF-7 cells,mouse breast cancer 4T1 cells,and human esophageal cancer K150 cells were used as the research objects to study the cytotoxicity of the NPY-RBC@ZIF-90@Ce6 material loaded with the photosensitizer Ce6 under non-light conditions,and to verify the different concentrations of this The effect of photodynamic therapy on MCF-7 cells under light conditions was strong.BALB/c mice were used as models to verify the biological safety of NPY-RBC@ZIF-90@Ce6 materials under non-light conditions.MCF-7 tumor-bearing animal models were established by BALB/c nude mice to study NPY-RBC@ZIF-90@Ce6 material in vivo tumor photodynamic therapy effect,proved that this drug delivery system can enhance the photodynamic therapy effect,the average tumor volume is only one sixth of the case of just inject Ce6 at same concentration for photodynamic therapy,and through tissue sectioning,Blood routine,weight record and other methods prove that this treatment is biologically safe.