A kind of transgenic vector based on polypeptide k12 and its application

Abstract

The present invention relates to a polypeptide K12 and a gene carrier modified by K12. The sequence of the polypeptide K12 is: Lys-Lys-Lys-Arg-Lys-Cys-Gly-Asn-Lys-Arg-Thr-Arg. Firstly, poloxamer 407 (P407) was selected to connect PEI to obtain high-molecular-weight PEI derivatives with multi-branched or network structure, and the tLyP-1 short peptide was selected to connect with the nuclear localization signal peptide NLS to synthesize a protein that targets NRP and The peptide K12 with improved nuclear delivery ability was coupled with PEI derivatives by cross-linking technology to construct a new non-viral gene carrier P407‑PEI‑K12. The results of cytotoxicity and transfection experiments show that the novel non-viral gene carrier system P407-PEI-K12 provided by the present invention not only has low toxicity, but also has stronger targeting, and the cell and in vivo transfection effects are better than those of the control group.

Description

technical field [0001] The invention relates to the technical field of medicine, in particular to a PEI derivative P407-PEI transgene carrier modified by polypeptide K12 and its application. Background technique [0002] Gene therapy is a new treatment method based on the principles of genetic engineering and molecular genetics in recent years. Because the biological basis of tumor occurrence and development is gene mutation, gene therapy has become the most promising field for conquering tumors. There are three important links in gene therapy, namely the target gene, transgenic carrier and target cells. The gene transfer 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. Currently applied vectors include two categories: 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-vira...

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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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