Protein-like particle and preparation method thereof

Abstract

The invention provides imitation protein particles and a preparation method thereof, and belongs to the technical field of nano materials. A double bond on a C chain segment in the biomimetic protein particle provided by the invention can be connected with a positive drug or a fluorophore through click chemistry, and a carboxyl group can be connected with a targeting peptide, a positive drug containing a hydroxyl group or an amino group and the like through DCC coupling, so that the magnetic biomimetic protein particle carrying drug molecules, the fluorophore and the targeting peptide is obtained, the hydrophilic chain segment A enables the biomimetic particle to be delivered in a living body, the hydrophilic chain segment B has magnetism and can penetrate some tissue fluid segments with resistance so as to enter parts where conventional drugs cannot enter for treatment, meanwhile, the targeting peptide can enable the biomimetic particle to be combined with in-vivo protein, so that the biomimetic particle can enter the living body more easily, and the biomimetic particle can be used for treating the tumor. The accumulation concentration of the medicine in a diseased region is effectively improved, and the curative effect is improved; the mimic protein particles are small in size, high in safety to human bodies and small in toxic and side effects.

Description

Technical Field

[0001] The present invention relates to the technical field of nanomaterials, and in particular to a protein-mimicking particle and a preparation method thereof. Background Art

[0002] Protein, as the scaffold and main substance constituting human tissues and organs, is an important class of chemical substances in natural organisms. Proteins in organisms are folded and assembled from polypeptide chains. Due to their complex sequences and diverse chemical functions, proteins can produce folded chains with highly specific structural definitions, while polypeptides have the same main-chain repeating sequences as proteins. In the 1940s, chemists and biochemists from all over the world began research projects in the emerging field of synthetic polypeptides. Since there are only 20 natural amino acids and the types of their side-chain functional groups are limited, researchers prepared artificial synthetic polyamino acids by the chemical method of ring-opening polymerization of α-amino acid-N-carboxylic acid anhydride (NCA) monomers, which can contain a variety of functional groups, and at the same time can rapidly prepare high-molecular-chain polypeptides with high yield and large scale, mimicking the folding of proteins in the human body, and having characteristics such as good biocompatibility, good biodegradability, multifunctionality, and low toxicity. Therefore, polyamino acids can be considered an ideal choice for drug delivery.

[0003] In addition, magnetic nanoparticles can be manipulated using magnetic fields and have interesting properties such as uniform size, high surface area, biocompatibility, superparamagnetism, adsorption kinetics, and magnetic moment. They have been widely used in fields such as hyperthermia, targeted drug delivery systems, imaging, biomolecule extraction, etc., and have become an important tool for tumor treatment. The synthesis methods of magnetic nanoparticles such as iron oxide nanoparticles include wet chemical or "bottom-up" approaches, such as hydrothermal, solvothermal, sol-gel, coprecipitation, flow injection synthesis, electrochemistry, laser pyrolysis technology, etc. By modifying the surface of magnetic nanoparticles, their properties such as biocompatibility, poor biodegradability, and chemical instability in the physiological environment can be improved. For example, magnetic nanoparticles are coated with biological functional molecules such as antibodies, ligands, or receptors, enabling them to have a highly affinity interaction with biological entities, thus providing a controllable "labeling" means and high selectivity and sensitivity for many biological applications. Currently, the net content of magnetic nanoparticles and similar protein-mimicking particles of metals is too high, lacking a biodegradable organic framework; and the synthesis steps are complex, requiring strict control of reaction conditions, and the production cost is high, making it difficult to produce in batches and limiting the feasibility of large-scale production. Summary of the Invention

[0004] The object of the present invention is to provide a protein-mimicking particle and a preparation method thereof. The protein-mimicking particle provided by the present invention has an asymmetric structure and excellent motility; the protein-mimicking particle has multiple double bonds and can be used as a nanocarrier to connect a positive drug through click chemistry; the multi-carboxyl structure endows it with good biocompatibility, and it can be connected with a targeting peptide through DCC coupling, showing targeting property; moreover, the protein-mimicking particle is small in size and can be excreted from the body through the kidneys in vivo, with high safety for the human body and low toxicity and side effects.

[0005] In order to achieve the above object of the invention, the present invention provides the following technical solutions:

[0006] The present invention provides a protein-mimicking particle, and the structure of the protein-mimicking particle is A-B-C; wherein the A segment is a hydrophilic linear polymer chain, B is a spherical or quasi-spherical nanoparticle, and the C segment is a linear polymer chain with double bonds and carboxyl groups in the side chain.

[0007] The number-average molecular weights of the A segment and the C segment are independently 50 to 5,000,000.

[0008] Preferably, the hydrodynamic diameter of the spherical or quasi-spherical nanoparticle B is 1 nm to 1000 nm; the C segment is a polyamino acid chain segment with double bonds and carboxyl groups in the side chain.

[0009] The present invention also provides a preparation method of the protein-mimicking particle according to the above technical solution, comprising the following steps:

[0010] Mix a hydrophilic linear polymer compound, a first NCA monomer and a first solvent, and carry out a ring-opening polymerization reaction to obtain a first block polymer.

[0011] Mix the first block polymer, a second NCA monomer and a second solvent, and carry out a polymerization reaction to obtain a second block polymer.

[0012] Mix the second block polymer, a metal carbonyl compound and a third solvent, and carry out a complex cross-linking reaction to obtain a single-chain nanoparticle.

[0013] Carry out post-treatment and deprotection reaction on the single-chain nanoparticle in sequence to obtain the protein-mimicking particle.

[0014] Preferably, the hydrophilic linear polymer compound is at least one of polyethylene glycol, polyacrylic acid, polymethacrylic acid, polyvinyl alcohol, polyethyleneimine, sodium polyacrylate, polyamino acid, and polyacrylamide.

[0015] Preferably, the first NCA monomer is at least one of but-3-yn-1-yl-L-glutamic acid-N-carboxyanhydride, prop-2-yn-1-yl-L-glutamic acid-N-carboxyanhydride, 4-(prop-2-yn-1-yloxy)-benzyl-L-glutamic acid-N-carboxyanhydride, 2-methyl-but-3-yn-1-yl-L-glutamic acid-N-carboxyanhydride, 2,2-dimethyl-but-3-yn-1-yl-L-glutamic acid-N-carboxyanhydride, pent-4-yn-1-yl-L-glutamic acid-N-carboxyanhydride, 1-methyl-but-3-yn-1-yl-L-glutamic acid-N-carboxyanhydride, 2-ethynyl-but-3-yn-1-yl-L-glutamic acid-N-carboxyanhydride, 3-methyl-pent-4-yn-1-yl-L-glutamic acid-N-carboxyanhydride, 2-methyl-pent-4-yn-1-yl-L-glutamic acid-N-carboxyanhydride, 1-methyl-pent-4-yn-1-yl-L-glutamic acid-N-carboxyanhydride.

[0016] Preferably, the second NCA monomer is at least one of an NCA monomer containing a double bond, an NCA monomer containing a tert-butyl ester group, and an NCA monomer containing a halogen functional group;

[0017] The NCA monomer containing a double bond is at least one of but-3-en-1-yl-L-glutamic acid-N-carboxyanhydride, prop-2-en-1-yl-L-glutamic acid-N-carboxyanhydride, 4-vinyloxybenzyl-L-glutamic acid-N-carboxyanhydride, 2-methyl-but-3-en-1-yl-L-glutamic acid-N-carboxyanhydride;

[0018] The NCA monomer containing a tert-butyl ester group is at least one of tert-butyl ester-L-glutamic acid-N-carboxyanhydride, methyl ester-L-glutamic acid-N-carboxyanhydride, benzyl ester-L-glutamic acid-N-carboxyanhydride, isobutyl ester-L-glutamic acid-N-carboxyanhydride;

[0019] The NCA monomer containing a halogen functional group is at least one of 3-chloro-prop-1-yl-L-glutamic acid-N-carboxyanhydride, 4-(chloromethyl)-1-benzyl-L-glutamic acid-N-carboxyanhydride, 2,2,2-trichloro-eth-1-yl-L-glutamic acid-N-carboxyanhydride, 4-(bromomethyl)-1-benzyl-L-glutamic acid-N-carboxyanhydride.

[0020] Preferably, the metal carbonyl compound is Co2(CO)8, Fe2(CO)9, Fe(CO)5, Ni(CO)4, Mn2(CO) 10 , Re2(CO) 10 , V(CO)6, Co4(CO) 12, Pt(CO)4, Pt(CO)3, Pt(CO)2, Pd(CO)4, Mo(CO)6, W(CO)6, Cr(CO)6, Ru3(CO) 12 , at least one of cis-dichlorodicarbonyl platinum.

[0021] Preferably, the solvent for the complex crosslinking reaction is at least one of o-dichlorobenzene, chlorobenzene, N,N-dimethylformamide, N,N-dimethylacetamide, tetrahydrofuran, dimethyl phthalate, dichloromethane, chloroform, 1,2-dichloroethane, 1,1,2,2-tetrachloroethane, toluene.

[0022] Preferably, the post-treatment is at least one of heating, catalytic hydrogenation, microwave treatment, high-energy electron beam treatment, γ-ray irradiation treatment, nuclear radiation treatment.

[0023] Preferably, when the post-treatment is heating, the heating temperature is 80-300 °C; the solvent used for heating is at least one of o-dichlorobenzene, N,N-dimethylformamide, N,N-dimethylacetamide, dimethyl phthalate, acetophenone.

[0024] The present invention provides a protein-mimicking particle, and the structure of the protein-mimicking particle is A-B-C; wherein the A segment is a hydrophilic linear polymer chain, B is a spherical or quasi-spherical nanoparticle, and the C segment is a linear polymer chain with double bonds and carboxyl groups in the side chain; the number-average molecular weights of the A segment and the C segment are independently 50 to 5000000. The C═C on the terminal C segment of the protein-mimicking particle provided by the present invention can be conjugated with a positive drug or a fluorescent group through click chemistry, and the carboxyl group can be coupled with a targeting peptide, a positive drug containing a hydroxyl group or an amino group, etc. through DCC coupling, so as to obtain a protein-mimicking particle with a size of 5 to 25 nm, having magnetism and carrying drug molecules, fluorescent groups, and targeting peptides. The innovation of the present invention lies in that the synthesized protein-mimicking particle has a smaller size than ordinary nano drug-loading materials. The hydrophilic linear polymer chain A can enable it to be delivered in vivo. B has magnetism and can penetrate some tissue fluid fragments with resistance, so as to enter parts that conventional drugs cannot enter for treatment. At the same time, the targeting peptide can enable it to bind to proteins in the body, making the protein-mimicking particle easier to enter the organism, effectively increasing the accumulation concentration of the drug at the lesion site; and the C segment has a multi-carboxyl structure, endowing it with good biocompatibility. The electrostatic adsorption between COO− and proteins is easily shielded by the ionic effect in the solution, reducing the surface adsorption amount, and having good biodegradability and low toxicity; at the same time, the protein-mimicking particle has an asymmetric structure, with the A segment as the molecular tail and the magnetic nanoparticle B as the head, enabling it to move forward in the tissue fluid like a worm. The protein-mimicking particle can enter it through its own peristalsis, making the drug easier to enter the lesion site, accumulate in the tumor site, and improve the curative effect; in addition, the protein-mimicking particle is at the nano level, with a small size. The A segment and the C segment (belonging to the polyamino acid segment) can be normally metabolized in the human body, have high safety for the human body, low side effects, and are easy to be excreted from the body, and have broad application prospects in the treatment of tumors and other diseases as a drug-loading material.

[0025] Moreover, the present invention selects polyamino acid as the backbone, which has good biocompatibility, can be compatible with tissues and cells in the organism, and reduces immune reactions and toxicity; has good biodegradability, can be decomposed into harmless small molecules through enzymatic degradation or hydrolysis, avoids long-term accumulation in the body, and reduces the toxicity problem during long-term use; has advantages such as high efficiency, controllability, and flexibility through ring-opening polymerization of α-amino acid-N-carboxyanhydrides (NCA) monomers, and can synthesize various polyamino acid materials with adjustable structures and diverse functions; by precisely controlling the polymerization reaction conditions, the degree of polymerization can be precisely regulated, and high-molecular-weight polymers can still be obtained at low degrees of polymerization; the method provided by the present invention has high synthesis efficiency, can obtain polymers with high yields in a short time, and has currently achieved kilogram-scale preparation, especially suitable for large-scale production. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 These are structural formula diagrams of the first NCA monomer and the second NCA monomer in the present invention. Among them, Figure 1 in a-1 is but-3-yn-1-yl-L-glutamic acid-N-carboxyanhydride, Figure 1 in a-2 is prop-2-yn-1-yl-L-glutamic acid-N-carboxyanhydride, Figure 1 in a-3 is 4-(prop-2-ynyloxy)-benzyl-L-glutamic acid-N-carboxyanhydride, Figure 1 in a-4 is 2-methyl-but-3-yn-1-yl-L-glutamic acid-N-carboxyanhydride, Figure 1 in a-5 is 2,2-dimethyl-but-3-yn-1-yl-L-glutamic acid-N-carboxyanhydride, Figure 1 in a-6 is pent-4-yn-1-yl-L-glutamic acid-N-carboxyanhydride, Figure 1 in a-7 is 1-methyl-but-3-yn-1-yl-L-glutamic acid-N-carboxyanhydride, Figure 1 in a-8 is 2-ethynyl-but-3-yn-1-yl-L-glutamic acid-N-carboxyanhydride, Figure 1 in a-9 is 3-methyl-pent-4-yn-1-yl-L-glutamic acid-N-carboxyanhydride, Figure 1 in a-10 is 2-methyl-pent-4-yn-1-yl-L-glutamic acid-N-carboxyanhydride, Figure 1 in a-11 is 1-methyl-pent-4-yn-1-yl-L-glutamic acid-N-carboxyanhydride, Figure 1 in b-1 is but-3-en-1-yl-L-glutamic acid-N-carboxyanhydride, Figure 1 in b-2 is prop-2-en-1-yl-L-glutamic acid-N-carboxyanhydride, Figure 1 in b-3 is 4-vinyloxybenzyl-L-glutamic acid-N-carboxyanhydride, Figure 1 in b-4 is 2-methyl-but-3-en-1-yl-L-glutamic acid-N-carboxyanhydride, Figure 1 in c-1 is tert-butyl ester-L-glutamic acid-N-carboxyanhydride, Figure 1 in c-2 is methyl ester-L-glutamic acid-N-carboxyanhydride, Figure 1 in c-3 is benzyl ester-L-glutamic acid-N-carboxyanhydride, Figure 1 in c-4 is isobutyl ester-L-glutamic acid-N-carboxyanhydride, Figure 1 in d-1 is 3-chloro-prop-1-yl-L-glutamic acid-N-carboxyanhydride, Figure 1 in d-2 is 4-(chloromethyl)-1-benzyl-L-glutamic acid-N-carboxyanhydride, Figure 1Among them, d-3 is 2,2,2-trichloro-ethyl-1-yl-L-glutamic acid-N-carboxyanhydride, Figure 1 Among them, d-4 is 4-(bromomethyl)-1-benzyl-L-glutamic acid-N-carboxyanhydride;

[0027] Figure 2 This is the TEM image of the single-chain nanoparticles and protein-mimicking particles prepared in Example 1 of the present invention, where Figure 2 A in it is the single-chain nanoparticle, Figure 2 B in it is the protein-mimicking particle;

[0028] Figure 3 This is the PEO 5k -Alk 30 -Eth 55 -tBA 52 structural diagram of the four-block copolymer and the protein-mimicking particle, where, Figure 3 A in it is the PEO 5k -Alk 30 -Eth 55 -tBA 52 four-block copolymer, Figure 3 B in it is the protein-mimicking particle;

[0029] Figure 4 This is the synthetic route diagram of the protein-mimicking particle prepared in Example 1 of the present invention;

[0030] Figure 5 This is the 1H NMR spectrum of the first block polymer PEO 5k -Alk 30 prepared in Example 1 of the present invention;

[0031] Figure 6 This is the 1H NMR spectrum of the PEO 5k -Alk 30 -Eth 55 -tBA 52 prepared in Example 1 of the present invention;

[0032] Figure 7 This is the GPC curve of MeO-PEO 5k -NH2, PEO 5k -Alk 30 and PEO 5k -Alk 30 -Eth 55 -tBA 52 prepared in Example 1 of the present invention. Detailed implementation manners

[0033] The present invention provides a protein-like particle, and the structure of the protein-like particle is A-B-C; wherein the A segment is a hydrophilic linear polymer chain, B is a spherical or quasi-spherical nanoparticle, and the C segment is a linear polymer chain with double bonds and carboxyl groups in the side chain;

[0034] The number-average molecular weights of the A segment and the C segment are independently 50 to 5000000.

[0035] In the present invention, unless otherwise specified, the raw materials used are all conventional commercially available products in the art.

[0036] In the present invention, the spherical or quasi-spherical nanoparticle B is preferably a metal nanoparticle, and more preferably composed of at least one of Co, Fe, Ni, Mn, Re, V, Co, Pt, Pd, Mo, W, Cr, Ru, and platinum. In the present invention, after the spherical or quasi-spherical nanoparticle B is crosslinked by alkynyl and metal carbonyl compounds and then thermally decomposed in the post-treatment, CO decomposes and leaves the basic metal composition in the polymer matrix. In the present invention, the hydrodynamic diameter of the spherical or quasi-spherical nanoparticle B is preferably 1 nm to 1000 nm, and more preferably 3 to 50 nm. The present invention controls the hydrodynamic diameter of B within the above range to more easily penetrate the physiological barrier, easily enter the cell nucleus, penetrate deep into the tumor, and show more accumulation in the tumor tissue; the smaller the size of the nanoparticle, the larger its specific surface area. Modify the surface of the nanoparticle to achieve efficient and specific drug delivery, improve the bioavailability of the drug, while reducing the contact of the drug with normal cells and reducing side effects.

[0037] The present invention also provides a preparation method of the protein-like particle described in the above technical solution, including the following steps:

[0038] Mix a hydrophilic linear polymer compound, a first NCA monomer, and a first solvent, and carry out a ring-opening polymerization reaction to obtain a first block polymer;

[0039] Mix the first block polymer, a second NCA monomer, and a second solvent, and carry out a polymerization reaction to obtain a second block polymer;

[0040] Mix the second block polymer, a metal carbonyl compound, and a third solvent, and carry out a complex crosslinking reaction to obtain a single-chain nanoparticle;

[0041] Carry out post-treatment and deprotection reaction on the single-chain nanoparticle in sequence to obtain the protein-like particle.

[0042] The present invention mixes a hydrophilic linear polymer compound, a first NCA monomer, and a first solvent, and carries out a ring-opening polymerization reaction to obtain a first block polymer.

[0043] In the present invention, the hydrophilic linear polymer compound is preferably at least one of methoxypolyethylene glycol amine, polyethylene glycol, polyacrylic acid, polymethacrylic acid, polyvinyl alcohol, polyethyleneimine, sodium polyacrylate, polyamino acid, and polyacrylamide, and more preferably polyethylene glycol.

[0044] In the present invention, the first NCA monomer preferably contains an alkyne functional group at the γ-position of the amino acid, and more preferably is at least one of 3-butyn-1-yl-L-glutamic acid N-carboxyanhydride, 2-propyn-1-yl-L-glutamic acid N-carboxyanhydride, 4-(2-propynyloxy)-benzyl-L-glutamic acid N-carboxyanhydride, 2-methyl-3-butyn-1-yl-L-glutamic acid N-carboxyanhydride, 2,2-dimethyl-3-butyn-1-yl-L-glutamic acid N-carboxyanhydride, 4-pentyn-1-yl-L-glutamic acid N-carboxyanhydride, 1-methyl-3-butyn-1-yl-L-glutamic acid N-carboxyanhydride, 2-ethynyl-3-butyn-1-yl-L-glutamic acid N-carboxyanhydride, 3-methyl-4-pentyn-1-yl-L-glutamic acid N-carboxyanhydride, 2-methyl-4-pentyn-1-yl-L-glutamic acid N-carboxyanhydride, and 1-methyl-4-pentyn-1-yl-L-glutamic acid N-carboxyanhydride.

[0045] In the present invention, the molar ratio of the hydrophilic linear polymer compound to the first NCA monomer is preferably 1:(25 - 200), more preferably 1:(30 - 150), and further preferably 1:50. The present invention controls the molar ratio of the hydrophilic linear polymer compound to the first NCA monomer within the above range to control the molar ratio to be 1:(25 - 200). During the NCA ring-opening polymerization reaction, according to the above reaction ratio, the average degree of polymerization of (Glu-yne) in the polymer can be effectively controlled to be 10 - 100, avoiding too short a polymer chain ((Glu-yne) is too small, and the subsequent cross-linking reaction is not easy to carry out, and the finally synthesized protein-like particles are too small) or too long (avoiding the finally synthesized protein-like particles being too large).

[0046] In the present invention, the first block polymer is preferably a block copolymer formed by two or more of the first NCA monomers, or a random copolymer formed by copolymerizing three or more of the first NCA monomers, and more preferably a polyethylene glycol homopolymer.

[0047] In the present invention, the temperature of the ring-opening polymerization reaction is preferably room temperature; the time of the ring-opening polymerization reaction is preferably 2 to 4 days; the ring-opening polymerization reaction is preferably carried out under stirring conditions. In the present invention, the first solvent is preferably at least one of DMF, ethyl acetate, methyl acetate, isopropyl alcohol, n-butanol, n-pentanol, ethylene glycol, glycerol, acetone, acetonitrile, methyl benzoate, dimethyl phthalate, dichloromethane, chloroform, 1,2-dichloroethane, 1,1,2,2,-tetrachloroethane, nitrobenzene, methanol, ethanol, dioxane, N,N-dimethylacetamide (DMA), o-dichlorobenzene, and tetrahydrofuran (THF). In the present invention, a polyamino acid segment containing a large number of alkyne functional groups is grown at one end of the segment A (formed by a hydrophilic linear polymer compound) through a ring-opening polymerization reaction.

[0048] After the ring-opening polymerization reaction is completed, the present invention preferably directly feeds the ring-opening polymerization reaction product for a polymerization reaction.

[0049] After obtaining the first block polymer, the present invention mixes the first block polymer, a second NCA monomer, and a second solvent and conducts a polymerization reaction to obtain a second block polymer.

[0050] In the present invention, the second NCA monomer is preferably at least one of an NCA monomer containing a double bond, an NCA monomer containing a tert-butyl ester group, and an NCA monomer containing a halogen functional group;

[0051] The NCA monomer containing a double bond is preferably at least one of 3-buten-1-yl-L-glutamic acid-N-carboxyanhydride, 2-propen-1-yl-L-glutamic acid-N-carboxyanhydride, 4-vinyloxybenzyl-L-glutamic acid-N-carboxyanhydride, and 2-methyl-3-buten-1-yl-L-glutamic acid-N-carboxyanhydride;

[0052] The NCA monomer containing a tert-butyl ester group is preferably at least one of tert-butyl ester-L-glutamic acid-N-carboxyanhydride, methyl ester-L-glutamic acid-N-carboxyanhydride, benzyl ester-L-glutamic acid-N-carboxyanhydride, and isobutyl ester-L-glutamic acid-N-carboxyanhydride;

[0053] The NCA monomer containing a halogen functional group is preferably at least one of 3-chloro-1-propyl-L-glutamic acid-N-carboxyanhydride, 4-(chloromethyl)-1-benzyl-L-glutamic acid-N-carboxyanhydride, 2,2,2-trichloro-1-ethyl-L-glutamic acid-N-carboxyanhydride, and 4-(bromomethyl)-1-benzyl-L-glutamic acid-N-carboxyanhydride.

[0054] In the present invention, the temperature of the polymerization reaction is preferably room temperature; the time of the polymerization reaction is preferably 1 to 3 days; the polymerization reaction is preferably carried out under stirring conditions. In the present invention, the second solvent is preferably at least one of DMF, ethyl acetate, methyl acetate, isopropanol, n-butanol, n-pentanol, ethylene glycol, glycerol, acetone, acetonitrile, methyl benzoate, dimethyl phthalate, dichloromethane, chloroform, 1,2-dichloroethane, 1,1,2,2-tetrachloroethane, nitrobenzene, methanol, ethanol, dioxane, N,N-dimethylacetamide (DMA), o-dichlorobenzene, and tetrahydrofuran (THF). In the present invention, a linear polymer chain C' with a double bond and a tert-butyl ester group in the side chain is formed at one end of the polyamino acid segment through a polymerization reaction. The segment C' is preferably formed by ring-opening homopolymerization of a second NCA monomer, random ring-opening copolymerization of multiple second NCA monomers, or sequential feeding of several first NCA monomers for step-by-step polymerization.

[0055] After the polymerization reaction is completed, the present invention preferably evaporates, redissolves, precipitates, and centrifuges the polymerization reaction product in sequence to obtain a second block polymer.

[0056] In the present invention, the evaporation is preferably rotary evaporation; the reagent used for redissolution is preferably dichloromethane; the reagent used for precipitation is preferably ether; the time of centrifugation is preferably 20 to 50 minutes, more preferably 30 minutes, and the rotation speed of centrifugation is preferably 4000 to 6000 rpm, more preferably 5000 rpm.

[0057] After obtaining the second block polymer, the present invention mixes the second block polymer, a metal carbonyl compound, and a third solvent to carry out a complex cross-linking reaction to obtain single-chain nanoparticles.

[0058] In the present invention, the metal carbonyl compound is preferably at least one of Co2(CO)8, Fe2(CO)9, Fe(CO)5, Ni(CO)4, Mn2(CO) 10 , Re2(CO) 10 , V(CO)6, Co4(CO) 12 , Pt(CO)4, Pt(CO)3, Pt(CO)2, Pd(CO)4, Mo(CO)6, W(CO)6, Cr(CO)6, Ru3(CO) 12 , and cis-dichlorodicarbonyl platinum.

[0059] In the present invention, the third solvent is preferably at least one of o-dichlorobenzene, chlorobenzene, N,N-dimethylformamide, N,N-dimethylacetamide, tetrahydrofuran, dimethyl phthalate, dichloromethane, chloroform, 1,2-dichloroethane, 1,1,2,2-tetrachloroethane, toluene, and more preferably dimethyl phthalate. The present invention uses the third solvent as the solvent for the complexation reaction, and utilizes its ability to dissolve both the polymer and the metal carbonyl compound while having relatively weak coordination ability to promote the smooth progress of the complexation crosslinking reaction.

[0060] In the present invention, the temperature of the complexation crosslinking reaction is preferably room temperature; the time of the complexation crosslinking reaction is preferably 3 - 5 d; the complexation crosslinking reaction is preferably carried out under stirring conditions. The present invention utilizes the coordination effect, and a large number of alkyne functional groups in the polyamino acid chain segment undergo a complexation crosslinking reaction with the metal carbonyl compound to achieve the folding of the chain segment and form a polyamino acid chain segment with a metal carbonyl compound.

[0061] After obtaining the single-chain nanoparticles, the present invention subjects the single-chain nanoparticles to post-treatment and deprotection reaction in sequence to obtain protein-mimicking particles.

[0062] In the present invention, the post-treatment is preferably at least one of heating, catalytic hydrogenation, microwave treatment, high-energy electron beam treatment, γ-ray irradiation treatment, nuclear radiation treatment.

[0063] In the present invention, when the post-treatment is heating, the heating temperature is preferably 80°C - 300°C, more preferably 100 - 200°C; the heating time is preferably 10 - 16 h, more preferably 12 - 14 h. In the present invention, the heating is preferably carried out in a nitrogen gas stream; the solvent used for heating is preferably at least one of o-dichlorobenzene, N,N-dimethylformamide, N,N-dimethylacetamide, dimethyl phthalate, acetophenone. The present invention causes the metal carbonyl compound in the structure of the polyamino acid chain segment with a metal carbonyl compound to undergo a thermal decomposition reaction through heating, dissociating the carbon monoxide component therein to form metal nanoparticles, namely spherical or quasi-spherical nanoparticles B.

[0064] In the present invention, the temperature of the deprotection reaction is preferably -50 - 100°C, more preferably 20 - 30°C, further preferably 25°C; the time of the deprotection reaction is preferably 12 - 96 h, more preferably 24 - 60 h, further preferably 48 h; all the reagents for the deprotection reaction are preferably at least one of trifluoroacetic acid, hydrochloric acid, sulfuric acid, nitric acid, glacial acetic acid, propionic acid, perchloric acid, phosphoric acid, hydrofluoric acid. The present invention removes the tert-butyl group on the side chain of the C' chain segment structure containing double bonds and tert-butyl ester groups through the deprotection reaction to form a linear polymer chain C with double bonds and carboxyl groups on the side chain, and finally obtains protein-mimicking particles with a chain-sphere-chain morphology.

[0065] The technical solutions of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0066] The sources of some raw materials used in the embodiments of the present invention are shown in Table 1, and the sources of the instruments are shown in Table 2.

[0067] Table 1 Sources of Some Raw Materials

[0068]

[0069]

[0070] Table 2 Sources of Instruments

[0071]

[0072]

[0073] The present invention synthesizes the three monomers of but-3-yn-1-yl-L-glutamic acid-N-carboxyanhydride (Alk-NCA), but-3-en-1-yl-L-glutamic acid-N-carboxyanhydride (Eth-NCA), and tert-butyl ester-L-glutamic acid-N-carboxyanhydride (tBA-NCA) used in the embodiments of the present invention in sequence according to Highly Efficient “Grafting onto” a Polypeptide Backbone Using Click Chemistry and The synthetic tuning of clickable pH responsive cationic polypeptides and block copolypeptides as the reference for Alk-NCA; Thiol-Ene Clickable Polypeptides as the reference for Eth-NCA; Synthesis and ring-opening (Co)polymerization of L-lysine N-carboxyanhydrides containing labile side-chain protective groups as the reference for tBA-NCA, specifically as follows:

[0074] (1) The preparation steps of Alk-NCA are as follows: Weigh 0.2 g of L-glutamic acid, 3 mL of 3-butyn-1-ol and 0.44 mL of trimethylchlorosilane into a 25 mL eggplant-shaped flask. React at 25 °C for 24 h under nitrogen. After that, the solution gradually becomes clear and the reaction ends. Precipitate in ether in small portions multiple times, centrifuge to obtain 0.32 g of intermediate 1a, which is a white solid. Weigh 0.8 g of intermediate 1a and 0.12 g of triphosgene into a 25 mL reaction tube, add 11 mL of ultra-dry ethyl acetate to the eggplant-shaped flask. Heat under reflux at 80 °C for 5 h under nitrogen. The solution gradually becomes clear and the reaction ends. Rotate the solvent to dryness, redissolve with a little dichloromethane, layer in n-hexane, and take the lower oily substance to obtain 0.24 g of Alk-NCA, which is a brown oily substance.

[0075] (2) The preparation steps of Eth-NCA are as follows: Weigh 1.0 g of L-glutamic acid, 10.3 mL of 3-buten-1-ol and 1 mL of trimethylchlorosilane into a 50 mL eggplant-shaped flask. Heat and react at 60 °C for 5 h. The solution gradually becomes clear and the reaction ends. Stop heating, rotate the solvent to dryness, then precipitate in ether in small portions multiple times and centrifuge to obtain 1.34 g of intermediate 2a, which is a white solid. Weigh 1.1 g of intermediate 2a and 0.7 g of triphosgene into a 100 mL eggplant-shaped flask, add 25 mL of ultra-dry tetrahydrofuran, react at room temperature. The solution changes from turbid to light yellow and clear (6 h), and the reaction ends. Rotate the solvent to dryness, redissolve with a little dichloromethane, layer in n-hexane, and take the lower oily substance to obtain 0.71 g of Eth-NCA, which is a light yellow oily substance.

[0076] (3) The preparation steps of tBA-NCA are as follows: Weigh 0.54 g of γ-tert-butyl-L-glutamic acid and 0.72 g of triphosgene into a 100 mL eggplant-shaped flask, add 16 mL of ultra-dry tetrahydrofuran, stir at 25 °C for 2 h under nitrogen atmosphere. The solution gradually becomes clear and the reaction ends. Rotate the solvent under reduced pressure to dryness, slowly add 15 mL of ultra-dry n-hexane dropwise into the eggplant-shaped flask (15 min), stir for 1 h under N2 atmosphere until no more solid precipitates. Filter, wash with ultra-dry n-hexane in small portions multiple times, and dry in a vacuum drying oven overnight to obtain 0.53 g of tBA-NCA, which is a white solid.

[0077] For those where specific experimental steps or conditions are not specified in the examples, the operations or conditions of the conventional experimental steps described in the literature in this field can be followed. All raw materials or instruments used are conventional products obtained through commercial purchase, including but not limited to the raw materials or instruments used in the examples of this application.

[0078] Example 1

[0079] An artificial protein particle, the structure of the artificial protein particle being A-B-C; wherein the A chain segment is a hydrophilic linear polymer chain, B is a spherical or quasi-spherical nanoparticle, and the C chain segment is a polyamino acid chain segment with double bonds and carboxyl groups in the side chain; the number-average molecular weight of the A chain segment is 5000, and the number-average molecular weight of the C chain segment is 19700; B is composed of Co and has a hydrodynamic diameter of ~10 nm;

[0080] The preparation method of the above artificial protein particle is as follows:

[0081] Dissolve polyethylene glycol methyl ether amine with a molecular weight of 5000 (100 mg, the structural formula is MeO-PEO 5k -NH2) in 2 mL of DMF to obtain a polyethylene glycol methyl ether amine solution. Dissolve the Alk-NCA monomer (225 mg) in 2 mL of DMF, add it to the above polyethylene glycol methyl ether amine solution, and stir at room temperature (25 °C) for 3 days to carry out a ring-opening polymerization reaction to obtain a first block polymer, simply referred to as PEO 5k -Alk 30 ;

[0082] Then dissolve the Eth-NCA monomer (227 mg) in 2 mL of DMF, add it to the first block polymer, and stir at room temperature (25 °C) for 1 day to obtain a mixture; finally, dissolve the tBA-NCA monomer (252 mg) in 2 mL of DMF, add it to the mixture, and stir at room temperature (25 °C) for 1 day. After the polymerization reaction is completed, spin-dry the solvent in the product of the polymerization reaction, redissolve it with dichloromethane, precipitate it in ether, centrifuge at 5000 rpm for 30 min, discard the supernatant, and repeat 3 times to obtain the sequential polymer PEO 5k -Alk 30 -Eth 55 -tBA 52 The tetra-block copolymer (i.e., the second block polymer) is a brown solid.

[0083] Dissolve the PEO 5k -Alk 30 -Eth 55 -tBA 52 tetra-block copolymer (50 mg) in 5 mL of DMP (dimethyl phthalate) to obtain a mixture. Dissolve 6.1 mg of Co2(CO)8 in 5 mL of DMP to obtain a Co2(CO)8 solution. Slowly drop the mixture and the Co2(CO)8 solution into 40 mL of DMP at the same time and stir for 2 days to carry out a complexation cross-linking reaction ( Figure 2 in A), to obtain single-chain nanoparticles;

[0084] Subsequently, 15 mL of single-chain nanoparticles were taken and heated at 180 °C for 12 h under a nitrogen gas stream to carry out a thermal decomposition reaction, obtaining the thermally decomposed nanoparticles. Then, the thermally decomposed nanoparticles were mixed with 35 μL of trifluoroacetic acid and the deprotection reaction was carried out at 25 °C for 48 h to remove the tert-butyl group, obtaining protein-mimicking particles ( Figure 2 in B).

[0085] Figure 2 Figure A in Figure 2 is the TEM image of the single-chain nanoparticles and protein-mimicking particles prepared in Example 1 of the present invention, where Figure 2 A in Figure 2 is the single-chain nanoparticle, and

[0086] Figure 3 Figure B in 5k -Alk 30 -Eth 55 -tBA 52 is the structural diagram of the PEO Figure 3 -Alk 5k -Eth 30 -tBA 55 tetra-block copolymer and the protein-mimicking particle. Among them, 52 A in Figure 3 is the PEO

[0087] Figure 4 is the synthetic route diagram of the protein-mimicking particles prepared in Example 1 of the present invention.

[0088] Figure 5 is the 1H NMR spectrum of the first block polymer PEO 5k -Alk 30 prepared in Example 1 of the present invention. From Figure 5 , through the attribution analysis of the 1H NMR spectrum, the average degree of polymerization of the Alk NCA monomer was calculated to be 30, and the M.W. of PEO 5k -Alk 30 was 10430 g / mol.

[0089] Figure 6 is the 1H NMR spectrum of PEO 5k -Alk 30 -Eth 55 -tBA 52 prepared in Example 1 of the present invention. From Figure 6 , through the attribution analysis of the 1H NMR spectrum, the average degrees of polymerization of the Eth NCA and tBA NCA monomers were calculated to be 55 and 52 respectively, and PEO5k -Alk 30 -Eth 55 -tBA 52 has an M.W. = 30115 g / mol.

[0090] MeO-PEO was detected 5k -NH2, PEO 5k -Alk 30 and PEO 5k -Alk 30 -Eth 55 -tBA 52 The GPC curve of... is as Figure 7 shown, and the distribution and polydispersity coefficient of MeO-PEO 5k -NH2 (as initiator), diblock polymer PEO 5k -Alk 30 and tetrablock polymer PEO 5k -Alk 30 -Eth 55 -tBA 52 were determined. The results are shown in Table 3 below to further verify the molecular weight of the polymer. From Figure 7 and Table 3, it can be seen that the larger the molecular weight of the polymer, the earlier the peak appears during GPC detection, and the GPC peak elution time corresponds to the molecular weight of each polymer; PEO 5k -Alk 30 -Eth 55 -tBA 52 has the largest molecular weight and the earliest peak elution time (15.63 min), and the molecular weight of the MeO-PEO 5k -NH2 initiator is the smallest, with the latest peak elution time (15.83 min). The PDI of each block polymer is below 1.2, indicating that the synthesis process of the polymer is well controlled, the molecular weight distribution of the polymer is narrow, the difference between the molecular weights of the polymer is small, and the polymer has good dispersibility and uniformity.

[0091] Table 3 Molecular weight and polydispersity information of MeO-PEO 5k -NH2, PEO 5k -Alk 30 and PEO 5k -Alk 30 -Eth 55 -tBA 52

[0092] Polymer <![CDATA[M n (NMR)]]> Elution time (min) PDI (GPC) <![CDATA[MeO-PEO 5k -NH2]]> 5000 15.83 1.1 <![CDATA[PEO 5k -Alk 30 > 10430 15.67 1.2 <![CDATA[PEO 5k -Alk 30 -Eth 55 -tBA 52 > 30115 15.63 1.2

[0093] Example 2

[0094] An artificial protein particle, the structure of the artificial protein particle is A-B-C; wherein the A chain segment is a hydrophilic linear polymer chain, B is a spherical or quasi-spherical nanoparticle, and the C chain segment is a polyamino acid chain segment with double bonds and carboxyl groups in the side chain; the number average molecular weight of the A chain segment is 5000, and the number average molecular weight of the C chain segment is 19700; B is composed of Co, and the hydrodynamic diameter is ~10 nm;

[0095] Prepare the artificial protein particle according to the method of Example 1, the difference from Example 1 is: dissolve the PEO 5k -Alk 30 -Eth 55 -tBA 52 tetra-block copolymer (100 mg) in 10 mL of o-DCB, swell, add 5 mL of DMF and dissolve to obtain a mixture, dissolve 12.2 mg of Co2(CO)8 in 10 mL of o-DCB to obtain a Co2(CO)8 solution, and slowly drop the mixture and the Co2(CO)8 solution into 5 mL of DMF at the same time, stir for 2 days to carry out a complex cross-linking reaction; then, heat at 180 °C for 12 h to carry out a thermal decomposition reaction to obtain the thermally decomposed nanoparticles, and then mix the thermally decomposed nanoparticles with trifluoroacetic acid, and carry out a deprotection reaction at 25 °C for 4 h to remove the tert-butyl group to obtain the artificial protein particle.

[0096] Example 3

[0097] An artificial protein particle, the structure of the artificial protein particle is A-B-C; wherein the A chain segment is a hydrophilic linear polymer chain, B is a spherical or quasi-spherical nanoparticle, and the C chain segment is a polyamino acid chain segment with double bonds and carboxyl groups in the side chain; the number average molecular weight of the A chain segment is 5000, and the number average molecular weight of the C chain segment is 19700; B is composed of Co, and the hydrodynamic diameter is ~10 nm;

[0098] Prepare the artificial protein particle according to the method of Example 1, the difference from Example 1 is: dissolve the PEO 5k -Alk 30 -Eth 55 -tBA 52 tetra-block copolymer (50 mg) in 5 mL of THF, dissolve 6.1 mg of Co2(CO)8 in 5 mL of THF, and slowly drop them into 5 mL of THF at the same time, stir for 2 days to carry out a complex cross-linking reaction; then, heat at 180 °C for 12 h to carry out a thermal decomposition reaction to obtain the thermally decomposed nanoparticles, and then mix the thermally decomposed nanoparticles with trifluoroacetic acid, and carry out a deprotection reaction at 25 °C for 48 h to remove the tert-butyl group to obtain the artificial protein particle.

[0099] Example 4

[0100] An artificial protein particle, the structure of the artificial protein particle being A-B-C; wherein the A segment is a hydrophilic linear polymer chain, B is a spherical or quasi-spherical nanoparticle, and the C segment is a polyamino acid chain segment with double bonds and carboxyl groups in the side chain; the number-average molecular weight of the A segment is 5000, and the number-average molecular weight of the C segment is 19700; B is composed of Co, and the hydrodynamic diameter is ~10 nm;

[0101] Prepare the artificial protein particle according to the method of Example 1, different from Example 1 in that: dissolve PEO 5k -Alk 30 -Eth 55 -tBA 52 The tetra-block copolymer (100 mg) is dissolved in 10 mL of DMA, 12.2 mg of Co2(CO)8 is dissolved in 10 mL of DMA, and they are slowly added dropwise to 5 mL of DMA at the same time, stirred for 2 days for complex cross-linking reaction; subsequently, heated at 180 °C for 12 h for thermal decomposition reaction to obtain the thermally decomposed nanoparticles, and then the thermally decomposed nanoparticles are mixed with trifluoroacetic acid, and the deprotection reaction is carried out at 25 °C for 48 h to remove the tert-butyl group to obtain the artificial protein particle.

[0102] Example 5

[0103] An artificial protein particle, the structure of the artificial protein particle being A-B-C; wherein the A segment is a hydrophilic linear polymer chain, B is a spherical or quasi-spherical nanoparticle, and the C segment is a polyamino acid chain segment with double bonds and carboxyl groups in the side chain; the number-average molecular weight of the A segment is 5000, and the number-average molecular weight of the C segment is 19700; B is composed of Fe, and the hydrodynamic diameter is ~10 nm;

[0104] Prepare the artificial protein particle according to the method of Example 1, different from Example 1 in that: dissolve PEO 5k -Alk 30 -Eth 55 -tBA 52 The tetra-block copolymer (100 mg) is dissolved in 90 mL of o-DCB, 13.9 mg of Fe(CO)5 is dissolved in 10 mL of o-DCB, the polymer solution is slowly added dropwise to the Fe(CO)5 solution, stirred for 2 days for complex cross-linking reaction; subsequently, heated at 180 °C for 12 h for thermal decomposition reaction to obtain the thermally decomposed nanoparticles, and then the thermally decomposed nanoparticles are mixed with trifluoroacetic acid, and the deprotection reaction is carried out at 25 °C for 48 h to remove the tert-butyl group to obtain the artificial protein particle.

[0105] Example 6

[0106] An artificial protein particle, the structure of the artificial protein particle being A-B-C; wherein the A segment is a hydrophilic linear polymer chain, B is a spherical or quasi-spherical nanoparticle, and the C segment is a polyamino acid chain segment with double bonds and carboxyl groups in the side chain; the number average molecular weight of the A segment is 5000, and the number average molecular weight of the C segment is 19700; B is composed of Fe and has a hydrodynamic diameter of ~10 nm;

[0107] Prepare the artificial protein particle according to the method of Example 1, differing from Example 1 in that: Dissolve PEO 5k -Alk 30 -Eth 55 -tBA 52 tetra-block copolymer (50 mg) in 45 mL of DMP, dissolve 7.0 mg of Fe(CO)5 in 5 mL of DMP, slowly drop the polymer solution into the Fe(CO)5 solution, stir for 2 days to carry out a complexation cross-linking reaction; subsequently, heat at 180 °C for 12 h to obtain the thermally decomposed nanoparticles, then mix the thermally decomposed nanoparticles with trifluoroacetic acid, carry out a deprotection reaction at 25 °C for 48 h to remove the tert-butyl group and obtain the artificial protein particle.

[0108] Example 7

[0109] An artificial protein particle, the structure of the artificial protein particle being A-B-C; wherein the A segment is a hydrophilic linear polymer chain, B is a spherical or quasi-spherical nanoparticle, and the C segment is a polyamino acid chain segment with double bonds and carboxyl groups in the side chain; the number average molecular weight of the A segment is 5000, and the number average molecular weight of the C segment is 19700; B is composed of Co and has a hydrodynamic diameter of ~10 nm;

[0110] Prepare the artificial protein particle according to the method of Example 1, differing from Example 1 in that: Dissolve PEO 5k -Alk 30 -Eth 55 -tBA 52 tetra-block copolymer (50 mg) in 5 mL of DCM, dissolve 6.1 mg of Co2(CO)8 in 5 mL of DCM, and slowly drop them simultaneously into 40 mL of DCM, stir for 2 days to carry out a complexation cross-linking reaction; subsequently, take 15 mL of the reaction solution under a nitrogen gas stream, replace the solvent with dimethyl phthalate at 180 °C, heat at 180 °C for 12 h to obtain the thermally decomposed nanoparticles, then mix the thermally decomposed nanoparticles with 35 μL of trifluoroacetic acid, carry out a deprotection reaction at 25 °C for 48 h to remove the tert-butyl group and obtain the artificial protein particle.

[0111] Example 8

[0112] An artificial protein particle, the structure of the artificial protein particle being A-B-C; wherein the A chain segment is a hydrophilic linear polymer chain, B is a spherical or quasi-spherical nanoparticle, and the C chain segment is a polyamino acid chain segment with double bonds and carboxyl groups in the side chain; the number average molecular weight of the A chain segment is 5000, and the number average molecular weight of the C chain segment is 19700; the B is composed of Fe and has a hydrodynamic diameter of ~10 nm;

[0113] Prepare the artificial protein particle according to the method of Example 1, the difference from Example 1 being that: dissolve PEO 5k -Alk 30 -Eth 55 -tBA 52 tetra-block copolymer (50 mg) in 5 mL DMP, dissolve 6.5 mg Fe2(CO)9 in 5 mL DMP, and slowly add them dropwise to 40 mL DMP at the same time, stir for 2 days to carry out complex cross-linking reaction; subsequently, take 15 mL of the reaction solution and heat it at 180 °C for 12 h to obtain the thermally decomposed nanoparticles, and then mix the thermally decomposed nanoparticles with 35 μL of trifluoroacetic acid, and carry out deprotection reaction at 25 °C for 48 h to remove the tert-butyl group to obtain the artificial protein particle.

[0114] Example 9

[0115] An artificial protein particle, the structure of the artificial protein particle being A-B-C; wherein the A chain segment is a hydrophilic linear polymer chain, B is a spherical or quasi-spherical nanoparticle, and the C chain segment is a polyamino acid chain segment with double bonds and carboxyl groups in the side chain; the number average molecular weight of the A chain segment is 5000, and the number average molecular weight of the C chain segment is 19700; the B is composed of Mn and has a hydrodynamic diameter of ~10 nm;

[0116] Prepare the artificial protein particle according to the method of Example 1, the difference from Example 1 being that: dissolve PEO 5k -Alk 30 -Eth 55 -tBA 52 tetra-block copolymer (50 mg) in 5 mL DMP, dissolve 6.9 mg Mn2(CO) 10 in 5 mL DMP, and slowly add them dropwise to 40 mL DMP at the same time, stir for 2 days to carry out complex cross-linking reaction; subsequently, take 15 mL of the reaction solution and heat it at 180 °C for 12 h to obtain the thermally decomposed nanoparticles, and then mix the thermally decomposed nanoparticles with 35 μL of trifluoroacetic acid, and carry out deprotection reaction at 25 °C for 48 h to remove the tert-butyl group to obtain the artificial protein particle.

[0117] Example 10

[0118] An artificial protein particle, the structure of the artificial protein particle being A-B-C; wherein the A segment is a hydrophilic linear polymer chain, B is a spherical or quasi-spherical nanoparticle, and the C segment is a polyamino acid chain segment with double bonds and carboxyl groups in the side chain; the number-average molecular weight of the A segment is 5000, and the number-average molecular weight of the C segment is 19700; B is composed of Cr, and the hydrodynamic diameter is ~10 nm;

[0119] Prepare the artificial protein particle according to the method of Example 1, the difference from Example 1 being that: Dissolve the PEO 5k -Alk 30 -Eth 55 -tBA 52 tetra-block copolymer (100 mg) in 5 mL of DMP, dissolve 15.7 mg of Cr(CO)6 in 5 mL of DMP, and slowly add them dropwise to 40 mL of DMP at the same time, stir for 2 days to carry out a complexation cross-linking reaction; Subsequently, take 15 mL of the reaction solution and heat it at 180 °C for 12 h to obtain the thermally decomposed nanoparticles, and then mix the thermally decomposed nanoparticles with 35 μL of trifluoroacetic acid, and carry out a deprotection reaction at 25 °C for 48 h to remove the tert-butyl group to obtain the artificial protein particle.

[0120] Example 11

[0121] An artificial protein particle, the structure of the artificial protein particle being A-B-C; wherein the A segment is a hydrophilic linear polymer chain, B is a spherical or quasi-spherical nanoparticle, and the C segment is a polyamino acid chain segment with double bonds and carboxyl groups in the side chain; the number-average molecular weight of the A segment is 5000, and the number-average molecular weight of the C segment is 19700; B is composed of Mo, and the hydrodynamic diameter is ~10 nm;

[0122] Prepare the artificial protein particle according to the method of Example 1, the difference from Example 1 being that: Dissolve the PEO 5k -Alk 30 -Eth 55 -tBA 52 tetra-block copolymer (100 mg) in 5 mL of DMP, dissolve 18.8 mg of Mo(CO)6 in 5 mL of DMP, and slowly add them dropwise to 40 mL of DMP at the same time, stir for 2 days to carry out a complexation cross-linking reaction; Subsequently, take 15 mL of the reaction solution and heat it at 180 °C for 12 h to obtain the thermally decomposed nanoparticles, and then mix the thermally decomposed nanoparticles with 35 μL of trifluoroacetic acid, and carry out a deprotection reaction at 25 °C for 48 h to remove the tert-butyl group to obtain the artificial protein particle.

[0123] Example 12

[0124] An artificial protein particle, the structure of the artificial protein particle being A-B-C; wherein the A segment is a hydrophilic linear polymer chain, B is a spherical or quasi-spherical nanoparticle, and the C segment is a polyamino acid chain segment with double bonds and carboxyl groups in the side chain; the number-average molecular weight of the A segment is 5000, and the number-average molecular weight of the C segment is 19700; B is composed of W and has a hydrodynamic diameter of ~10 nm;

[0125] Prepare the artificial protein particle according to the method of Example 1, the difference from Example 1 being that: Dissolve the PEO 5k -Alk 30 -Eth 55 -tBA 52 tetra-block copolymer (100 mg) in 5 mL of DMP, dissolve 25.0 mg of W(CO)6 in 5 mL of DMP, and slowly add them dropwise to 40 mL of DMP at the same time, stir for 2 days to carry out a complexation crosslinking reaction; Subsequently, take 15 mL of the reaction solution and heat it at 180 °C for 12 h to obtain the thermally decomposed nanoparticles, and then mix the thermally decomposed nanoparticles with 35 μL of trifluoroacetic acid, and carry out a deprotection reaction at 25 °C for 48 h to remove the tert-butyl group to obtain the artificial protein particle.

[0126] Example 13

[0127] An artificial protein particle, the structure of the artificial protein particle being A-B-C; wherein the A segment is a hydrophilic linear polymer chain, B is a spherical or quasi-spherical nanoparticle, and the C segment is a polyamino acid chain segment with double bonds and carboxyl groups in the side chain; the number-average molecular weight of the A segment is 5000, and the number-average molecular weight of the C segment is 19700; B is composed of Ni and has a hydrodynamic diameter of ~10 nm;

[0128] Prepare the artificial protein particle according to the method of Example 1, the difference from Example 1 being that: Dissolve the PEO 5k -Alk 30 -Eth 55 -tBA 52 tetra-block copolymer (100 mg) in 5 mL of DMP, dissolve 12.1 mg of Ni(CO)4 in 5 mL of DMP, and slowly add them dropwise to 40 mL of DMP at the same time, stir for 2 days to carry out a complexation crosslinking reaction; Subsequently, take 15 mL of the reaction solution and heat it at 180 °C for 12 h to obtain the thermally decomposed nanoparticles, and then mix the thermally decomposed nanoparticles with 35 μL of trifluoroacetic acid, and carry out a deprotection reaction at (25) °C for 48 h to remove the tert-butyl group to obtain the artificial protein particle.

[0129] The protein-mimicking particles provided by the present invention have an asymmetric structure and excellent motility; the protein-mimicking particles have multiple double bonds and can be used as a nanocarrier to connect a positive drug through click chemistry; the multi-carboxyl structure endows them with good biocompatibility, enabling them to be connected with a targeting peptide through DCC coupling and having targeting properties; moreover, the nanoparticle has a small size, can be excreted from the body through the kidneys in vivo, has high safety for the human body, and has small toxic and side effects.

[0130] The above are only the preferred embodiments of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and refinements can be made, and these improvements and refinements should also be regarded as the protection scope of the present invention.

Claims

1. A protein-like particle, characterized in that, The structure of the protein-mimicking particle is A-B-C; wherein the A chain segment is a hydrophilic linear polymer chain, B is a spherical or quasi-spherical nanoparticle, and the C chain segment is a linear polymer chain with double bonds and carboxyl groups in the side chain; The number-average molecular weight of the A chain segment and the C chain segment is independently 50 to 5,000,000.

2. The protein-like particle according to claim 1, wherein The hydrodynamic diameter of the spherical or quasi-spherical nanoparticle B is 1 nm to 1000 nm; the C chain segment is a polyamino acid chain segment with double bonds and carboxyl groups in the side chain.

3. A method for preparing the protein-mimicking particle according to claim 1 or 2, characterized in that, It includes the following steps: Mix a hydrophilic linear polymer compound, a first NCA monomer, and a first solvent, and carry out a ring-opening polymerization reaction to obtain a first block polymer; Mix the diblock polymer, a second NCA monomer, and a second solvent, and carry out a polymerization reaction to obtain a second block polymer; Mix the second block polymer, a metal carbonyl compound, and a third solvent, and carry out a complexation cross-linking reaction to obtain single-chain nanoparticles; Carry out post-treatment and deprotection reactions on the single-chain nanoparticles in sequence to obtain protein-mimicking particles.

4. The method for preparing the protein-like particles according to claim 3, wherein The hydrophilic linear polymer compound is at least one of polyethylene glycol, polyacrylic acid, polymethacrylic acid, polyvinyl alcohol, polyethyleneimine, sodium polyacrylate, polyamino acid, and polyacrylamide.

5. The method for preparing the protein-mimicking particles according to claim 3, wherein, The first NCA monomer is at least one of but-3-yn-1-yl-L-glutamic acid-N-carboxyanhydride, prop-2-yn-1-yl-L-glutamic acid-N-carboxyanhydride, 4-(prop-2-yn-1-yloxy)-benzyl-L-glutamic acid-N-carboxyanhydride, 2-methyl-but-3-yn-1-yl-L-glutamic acid-N-carboxyanhydride, 2,2-dimethyl-but-3-yn-1-yl-L-glutamic acid-N-carboxyanhydride, pent-4-yn-1-yl-L-glutamic acid-N-carboxyanhydride, 1-methyl-but-3-yn-1-yl-L-glutamic acid-N-carboxyanhydride, 2-ethynyl-but-3-yn-1-yl-L-glutamic acid-N-carboxyanhydride, 3-methyl-pent-4-yn-1-yl-L-glutamic acid-N-carboxyanhydride, 2-methyl-pent-4-yn-1-yl-L-glutamic acid-N-carboxyanhydride, and 1-methyl-pent-4-yn-1-yl-L-glutamic acid-N-carboxyanhydride.

6. The method for preparing the protein-like particle according to claim 3, wherein, The second NCA monomer is at least one of an NCA monomer containing a double bond, an NCA monomer containing a tert-butyl ester group, and an NCA monomer containing a halogen functional group; The NCA monomer containing a double bond is at least one of but-3-en-1-yl-L-glutamic acid-N-carboxyanhydride, prop-2-en-1-yl-L-glutamic acid-N-carboxyanhydride, 4-vinyloxybenzyl-L-glutamic acid-N-carboxyanhydride, and 2-methyl-but-3-en-1-yl-L-glutamic acid-N-carboxyanhydride; The NCA monomer containing a tert-butyl ester group is at least one of tert-butyl ester-L-glutamic acid-N-carboxyanhydride, methyl ester-L-glutamic acid-N-carboxyanhydride, benzyl ester-L-glutamic acid-N-carboxyanhydride, and isobutyl ester-L-glutamic acid-N-carboxyanhydride; The NCA monomer containing a halogen functional group is at least one of 3-chloro-prop-1-yl-L-glutamic acid-N-carboxyanhydride, 4-(chloromethyl)-1-benzyl-L-glutamic acid-N-carboxyanhydride, 2,2,2-trichloro-eth-1-yl-L-glutamic acid-N-carboxyanhydride, and 4-(bromomethyl)-1-benzyl-L-glutamic acid-N-carboxyanhydride.

7. The preparation method of the protein-like particle according to claim 3, characterized in that, The metal carbonyl compound is at least one of Co2(CO)8, Fe2(CO)9, Fe(CO)5, Ni(CO)4, Mn2(CO) 10 , Re2(CO) 10 , V(CO)6, Co4(CO) 12 , Pt(CO)4, Pt(CO)3, Pt(CO)2, Pd(CO)4, Mo(CO)6, W(CO)6, Cr(CO)6, Ru3(CO) 12 , and cis-dichlorodicarbonyl platinum 8. The method for preparing the protein-like particles according to claim 3, wherein The solvent for the complex cross-linking reaction is at least one of o-dichlorobenzene, chlorobenzene, N,N-dimethylformamide, N,N-dimethylacetamide, tetrahydrofuran, dimethyl phthalate, dichloromethane, chloroform, 1,2-dichloroethane, 1,1,2,2-tetrachloroethane, and toluene.

9. The method for preparing the protein-like particles according to claim 3, wherein The post-treatment is at least one of heating, catalytic hydrogenation, microwave treatment, high-energy electron beam treatment, γ-ray irradiation treatment, and nuclear radiation treatment.

10. The method for preparing the protein-like particles according to claim 3, characterized in that, When the post-treatment is heating, the heating temperature is 80 to 300 °C; the solvent used for heating is at least one of o-dichlorobenzene, N,N-dimethylformamide, N,N-dimethylacetamide, dimethyl phthalate, and acetophenone.

Images