Polypeptide K12-based transgenic vector and application thereof

Abstract

The invention relates to a polypeptide K12 and a K12-modified gene vector. The sequence of the polypeptide K12 is Lys-Lys-Lys-Arg-Lys-Cys-Gly-Asn-Lys-Arg-Thr-Arg; and the gene vector is prepared by the following steps: firstly, selecting poloxamer 407 (P407) and connecting to PEI (polyether-imide) to obtain a high molecular weight PEI derivative with a multi-branch form or a network structure; selecting a tLyP-1 oligopeptide, connecting with a nuclear localization signal peptide (NLS), and synthesizing the polypeptide K12 which targets NRP and is capable of improving the nuclear delivery ability; coupling the K12 to the EPI derivative by employing a crosslinking technique, and building a novel non-viral gene vector P407-PEI-K12. The cytotoxicity and transfection experiment results prove that the novel non-viral gene vector system P407-PEI-K12 provided by the invention is low in toxicity and has relatively high targeting property; and the cell and in-vivo transfection effects of the gene vector are superior to those of a control group.

Description

Technical field [0001] The present invention relates to the field of medical technology, in particular to a P407-PEI transgenic vector modified by polypeptide K12 of PEI derivative and its application. Background technique [0002] Gene therapy is a new type of treatment method based on genetic engineering technology and molecular genetics in recent years. Because the biological basis of tumor development is gene mutation, gene therapy has now become the most promising field for fighting tumors. There are three important links in gene therapy, namely the target gene, the transgenic vector and the target cell. The gene infusion system is the core technology of gene therapy. The biggest problem at this stage is that the ideal gene carrier has not yet been found. The currently used vectors include viral vectors and non-viral vectors. Viral vectors have high transfection efficiency but have problems such as low carrying capacity and potential safety threats. Non-viral vectors have ...

AI Technical Summary

Problems solved by technology

However, there are two outstanding problems in the use of polyethyleneimine as a gene carrier: first, there is a contradiction between transfection efficiency and cytotoxicity

Although small molecule PEI has low cytotoxicity, it is easy to dissociate with DNA at physiological ion concentration, resulting in poor transfection effect; although PEI with a molecular weight above 20kd has a relatively ideal transfection rate, because the surface of PEI is rich in positive High molecular weight PEI exhibits strong cytotoxicity due to its charge and non-degradability in vivo

Second, polyethyleneimine has poor targeting: it uses its own positive charge to combine with negatively charged receptors on the cell surface through electrostatic interaction, so the specificity of cell selection is poor, and solving the targeting problem has become a Top concerns in non-viral vectors

However, there is no report about the poloxamer 407-polyethyleneimine modified by the polypeptide tLyP-1-NLS

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