TMVP1 Modified Indocyanine Green Loaded Nano-micelles For Sentinel Lymph Node Imaging With Tumor Metastasis

Objective:The purpose of this study was to research the effect of a molecular imaging nanomedicine TMVP1-ICG-NP in the detection of metastatic sentinel lymph nodes.TMVP1 was screened by the Fli Trx bacterial peptide display system in our laboratory with a sequence of LARGR,and it could specially bind to VEGFR-3 which expressed on the neolymphatic vessels in the sentinel lymph node with tumor metastasis.This research used TMVP1-modified polymer nanomaterials to load near-infrared fluorescent dye of indocyanine green(ICG)to improve its blood stability and also enable it to target to tumor metastasis sentinel lymph node;and then we explored the capability of TMTP1-ICG-NP to accurately identify tumor metastasis sentinel lymph nodes.Methods:1.We prepared nanomedicine of TMVP1-ICG-NP using nano-preicipitation method,and detected its particle diameter,morphology,drug encapsulation efficiency,UV absorption spectrum,cytotoxicity,and pharmacokinetic properties.2.We constructed cell lines with VEGFR-3 overexpression in vitro,and then identified the targeting ability of TMVP1-ICG-NP to VEGFR-3 overexpression cells.3.Mouse subcutaneous tumor model and sentinel lymph node metastasis animal model were used to verify the targeting ability of TMVP1-ICG-NP for tumor in situ and sentinel lymph node with metastasis in vivo.4.Immunohistochemistry were performed to verify the expression of VEGFR-3 in the tissues.Results:1.TMVP1-ICG-NP with a diameter of about 150 nm and an ICG loading rate of 70% was successfully prepared,the optical properties of ICG has not changed significantly,it has a lower cytotoxicity and prolonged blood circulation time.2.In vitro cell experiments confirmed that TMVP1-ICG-NP has good targeting ability on mouse breast cancer cell line 4T1 and human cervical epidermoid carcinoma cell line MS751 with VEGFR-3 overexpression.3.Compared with the nanomedicine ICG-NP which without tumor targeting peptide modification,the near-infrared light in the TMVP1-ICG-NP group has more aggregation in the sentinel lymph node with tumor metastasis and tumor in situ imaged by live small animal imaging.4.Immunohistochemistry indicated that the expression of VEGFR-3 exists in sentinel lymph nodes of tumor metastasis,and its expression is distributed along the new lymphatic vessels.Conclusions:TMVP1-ICG-NP could accurately identify the sentinel lymph node with tumor metastasis in vivo.TMVP1-ICG-NP has good safety which could be great potential in clinical transformation.It is expected to provide real-time near-infrared fluorescence guidance for intraoperative sentinel lymph node biopsy.