The Experimental Research Of ¹³¹I-antiEGFR-BSA-PCL Nuclide Nano-particle Carrier

Objective Radionuclide therapy is an effective method, the method is commonly used in clinical treatment of primary malignant and malignant metastases. In particular, the radioactive iodine for the treatment of thyroid cancer as well as radiolabeled targeting drugs in the clinical treatment of malignant tumors is quite mature treatments. Properties of nano particles are a small particle size, can easily be taken up by cells, and slow release, and it as a carrier of anticancer drugs in the treatment of malignant tumors also plays a huge role. Epidermal growth factor(EGFR) highly expressed in a variety of tumor cells, and there is a lot of literature reports have been reported that the overexpression of EGFR has the closely relationship with the poor tumors’ prognosis. Currently anti-EGFR targeted drugs in the treatment of malignant tumors has also been considerable development, a lot of anti-EGFR targeting drug has received US FDA certification. However, a single method of treatment exhibits many disadvantages in the treatment of malignant tumors, it will be an effective combination of radioactive iodine therapy, nanoparticle carriers and anti-EGFR drugs targeting the three together, for diagnosis and targeted treatment of malignant tumors with high expression of EGFR has potential research value.Methods(1) The novel protein-polymer conjugates were fabricated using bovine serum albumin(BSA) as substrate, then synthetic nanocarriers. Amphiphilic BSApolycaprolactone(PCL) synthesis and structural characterization of binding body;constructing BSA-PCL nanoparticles for targeting drug(cetuximab) carrier.polymersome was constructed by the self-assembly of amphiphilic BSA-PCL conjugate and cetuximab as a targeting ligand was linked to the periphery of the vesicle, and to use the functional groups contained on the surface of the nanoparticles,to targeted modify the polymer surface of liposomes. In addition, the cell experiments MTT assay results show that the BSA-PCL conjugate had a low cytotoxicity and better biocompatibility.(2) Based on cytological experiments verified that with high expression of EGFRtumor cells can uptake nanocarriers: confocal microscopy and flow cytometry experiments verified that tumor cells uptake anti EGFR-BSA-PCL, BSA-PCL the two kinds nanocarrier; MTT experiments showed the toxic effects of two kinds nanocarriers BSA-PCL and anti EGFR-BSA-PCL to tumor cells.(3) 131 I labeled nanocarriers, and cell experiments MTT assay comfirmed that131I-labeled nanocarriers have a killing effect on tumor cells.(4) At last, on the basis of cytological experiments, constructed a nude mouse model,and the two kinds 131 I labeled nanocarriers were injected into nude mice, then performed scintigraphy, virified the inhibition of 131I-labeled two nanocarriers for tumor growth in nude mice, and the influence of the life cycle of a tumor-burdened nude mice.Results(1) Successfully prepared amphiphilic nanocarriers(BSA-PCL), and completed the assembly of anti-EGFR antibody(cetuximab) and nanocarriers(Materials provided by the Tianjin University Professor Chang-jin laboratory research group), cytology experiment confirmed that the nanocarriers with very low cytotoxicity and good biocompatibility.(2) Confocal microscopy and flow cytometry experiments confirmed that tumor cells can uptake nanocarriers, the ability of cellular uptake of anti-EGFR targeted nanocarrier was much higher than non-targeted nanocarriers, MTT assay demonstrated the two nanocarriers(anti EGFR-BSA-PCL,BSA-PCL) itselves have low cytotoxicity on the growth of tumor cells.(3) The rate of 131 I labeled was up to 85%-90%; MTT assay confirmed that killing effect of131I-labeled anti-anti EGFR-BSA-PCL on tumor cells is much higher than non-targeted nanocarriers.(4) Animal experiments: Successfully constructed the nude mouse model of glioma(U87) and human colon adenocarcinoma cells(LS 180), successfully realization of the 131I-anti EGFR-BSA-PCL, 131I-BSA-PCL nanocarrier scintigraphy,131I-anti EGFR-BSA-PCL has the role of good inhibition of tumor growth and prolong the lifetime of tumor-bearing mice.Conclusion The tumor cell which high expression EGFR could uptake the131I-labeled and amphiphilic anti EGFR-BSA-PCL effectively, and two kinds of nanocarrier itself very low cytotoxicity of tumor cells and good biocompatibility; and the killing effect of 131I-anti EGFR-BSA-PCL is more stronger on tumor cells;131I-anti EGFR-BSA-PCL enables imaging of transplanted tumors in nude mice, and can inhibit tumor growth, extends the life cycle of nude mice, combined the imaging and radionuclide therapy effectively.