Polypeptide carrier used for improving targeting ability and transfection efficiency of medicine/gene, and purpose thereof

Abstract

The invention discloses a polypeptide carrier used for improving targeting ability and transfection efficiency of a medicine / gene. The polypeptide carrier has a structure represented by a formula (I): TATp-Cys-LHRHp (I), wherein TATp is a TAT fragment of HIV, Cys is Cysteine, LHRHp is an analogue of luteinizing hormone releasing hormone LHRH. The polypeptide carrier provided by the invention carries a large amount of positive charges. The polypeptide carrier has good water-solubility and high targeting ability aiming at sexual hormone dependent tumor and liver cancer. The carrier can directlycarry negatively charged nucleic acid or medicine, and mediate the nucleic acid or medicine into cells. Also, the carrier can be used for modifying other gene or medicine carriers, such that tumor targeting abilities and transfection efficiency of the gene or medicine carriers can be improved. Therefore, a novel carrier is provided for gene / medicine delivering.

Description

technical field

[0001] The invention belongs to the technical field of biological materials, and specifically relates to a polypeptide carrier for improving drug / gene targeting and transfection efficiency and its application. Background technique

[0002] Cancer is one of the most common causes of morbidity and mortality today, with more than 10 million new cases and 6.2 million deaths worldwide every year. The latest statistics show that in the past two decades, the cancer mortality rate in China has increased by nearly 30%, and one out of every four or five deaths is due to cancer, ranking first among the causes of death. However, due to the lack of targeting, current cancer chemotherapy drugs kill cancer cells and cause normal cells to die, resulting in severe systemic side effects for patients. Therefore, the development of efficient targeted gene / drug carriers plays a vital role in tumor therapy.

[0003] Cell penetrating peptides are a class of polypeptides that can ...

Examples

Embodiment 1

[0060] Synthesis and Characterization of Polypeptide TATp-Cys-LHRHp

[0061] Apply peptide synthesizer, adopt solid-phase peptide synthesis technology to carry out peptide synthesis, the result of mass spectrometry analysis shows that its molecular ion peak is 2657 (see figure 1 ), consistent with the expected molecular weight of the polypeptide, analyzed by HPLC, its purity is greater than 99% (see figure 2 )

Embodiment 2

[0063] Preparation of TATp-Cys-LHRHp gene-carrying nanoparticles

[0064] Dissolve the polypeptide carrier (TATp-Cys-LHRHp) and plasmid DNA in water to prepare an aqueous solution, and then place the two aqueous solutions in a water bath at 37°C for 10 minutes; N / P (is it a molar ratio?) ratio of 10:1 The two solutions were quickly mixed and vortexed for 50 seconds to obtain TATp-Cys-LHRHp gene-carrying nanoparticles. The average particle size of the nanoparticles is about 82nm, and the zeta potential is 26mV.

[0065] N / P can be selected from 2:1 to 20:1, and the shaking time is selected from 40 to 60 seconds. The obtained TATp-Cys-LHRHp gene-carrying nanoparticles have an average particle size of about 70-90 nm and a zeta potential of 20-40mY.

Embodiment 3

[0067] Cell transfection experiments of TATp-Cys-LHRHp gene-carrying nanoparticles

[0068] According to the preparation method of TATp-Cys-LHRHp gene-loaded nanoparticles in Example 2, TATp-Cys-LHRHp gene-loaded nanoparticles with an N / P ratio of 10:1 were prepared, and then the nanoparticles were transfected into human liver cancer cells BEL-7402 and For normal human liver cells LO2, the amount of transfected nanoparticles is 5 μg DNA / ml calculated by DNA. After 24 hours of transfection, the results of high-content live cell imaging show that the nanoparticles have strong targeting effect on liver cancer cells BEL-7402 , its transfection efficiency is high, but the normal liver cell LO2 transfection efficiency is very low.

technical field

[0001] The invention belongs to the technical field of biological materials, and specifically relates to a polypeptide carrier for improving drug / gene targeting and transfection efficiency and its application. Background technique

[0002] Cancer is one of the most common causes of morbidity and mortality today, with more than 10 million new cases and 6.2 million deaths worldwide every year. The latest statistics show that in the past two decades, the cancer mortality rate in China has increased by nearly 30%, and one out of every four or five deaths is due to cancer, ranking first among the causes of death. However, due to the lack of targeting, current cancer chemotherapy drugs kill cancer cells and cause normal cells to die, resulting in severe systemic side effects for patients. Therefore, the development of efficient targeted gene / drug carriers plays a vital role in tumor therapy.

[0003] Cell penetrating peptides are a class of polypeptides that can ...

Examples

Embodiment 1

[0060] Synthesis and Characterization of Polypeptide TATp-Cys-LHRHp

[0061] Apply peptide synthesizer, adopt solid-phase peptide synthesis technology to carry out peptide synthesis, the result of mass spectrometry analysis shows that its molecular ion peak is 2657 (see figure 1 ), consistent with the expected molecular weight of the polypeptide, analyzed by HPLC, its purity is greater than 99% (see figure 2 )

Embodiment 2

[0063] Preparation of TATp-Cys-LHRHp gene-carrying nanoparticles

[0064] Dissolve the polypeptide carrier (TATp-Cys-LHRHp) and plasmid DNA in water to prepare an aqueous solution, and then place the two aqueous solutions in a water bath at 37°C for 10 minutes; N / P (is it a molar ratio?) ratio of 10:1 The two solutions were quickly mixed and vortexed for 50 seconds to obtain TATp-Cys-LHRHp gene-carrying nanoparticles. The average particle size of the nanoparticles is about 82nm, and the zeta potential is 26mV.

[0065] N / P can be selected from 2:1 to 20:1, and the shaking time is selected from 40 to 60 seconds. The obtained TATp-Cys-LHRHp gene-carrying nanoparticles have an average particle size of about 70-90 nm and a zeta potential of 20-40mY.

Embodiment 3

[0067] Cell transfection experiments of TATp-Cys-LHRHp gene-carrying nanoparticles

[0068] According to the preparation method of TATp-Cys-LHRHp gene-loaded nanoparticles in Example 2, TATp-Cys-LHRHp gene-loaded nanoparticles with an N / P ratio of 10:1 were prepared, and then the nanoparticles were transfected into human liver cancer cells BEL-7402 and For normal human liver cells LO2, the amount of transfected nanoparticles is 5 μg DNA / ml calculated by DNA. After 24 hours of transfection, the results of high-content live cell imaging show that the nanoparticles have strong targeting effect on liver cancer cells BEL-7402 , its transfection efficiency is high, but the normal liver cell LO2 transfection efficiency is very low.

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