A calcium carbonate-based degradable organic-inorganic hybrid nanoparticle and a method for preparing the same

Abstract

The application discloses a kind of degradable organic-inorganic hybrid nanoparticles based on calcium carbonate and preparation method thereof, the preparation method of the application uses calcium carbonate and amphiphilic block copolymer as raw material, uses amphiphilic block copolymer as organic matrix, and uses calcium carbonate aqueous solution as inorganic matrix, water-soluble drug doxorubicin hydrochloride (DOX·HCl) is wrapped in nanoparticle, and a kind of calcium carbonate-based hybrid nanoparticle is prepared using stirring mixing technology.The nanoparticle prepared by the application has moderate particle size, uniform particle size distribution, good biocompatibility and biodegradability, and is expected to become a novel drug delivery carrier.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of high polymer material synthesis, and particularly relates to a degradable organic-inorganic hybrid nanoparticle based on calcium carbonate and a preparation method thereof. BACKGROUND

[0002] Cancer is one of the major diseases threatening human health worldwide, and the main treatment methods for cancer at present include surgical treatment, radiotherapy and drug therapy. Studies have shown that in the process of traditional drug treatment of cancer, the chemotherapeutic drugs need to overcome various obstacles in the body after intravenous injection to effectively enter the tumor cells. Compared with traditional drug-based chemotherapy, the nano drug delivery system has the following advantages: (1) the nano delivery system itself can have a means of diagnosing or treating cancer; (2) the nano delivery system can load multiple drug molecules for treating cancer to achieve a synergistic therapeutic effect; (3) the nano delivery system can improve its specific targeting effect on tumor sites through passive targeting and active targeting; (4) the nano delivery system can improve the concentration of drugs in cancer cells through drug release, while reducing the toxic side effects of drugs on normal cells, thereby achieving the effect of enhancing the anti-tumor effect and reducing the systemic toxicity.

[0003] Nano-particle-based drug delivery systems have been shown to be an advantageous strategy to improve drug bioavailability and overcome biological barriers in vitro and in vivo. Nanoparticle preparation involves a wide range of nanomaterials, including liposomes, polymers, inorganic compounds and hybrid materials. Among them, inorganic nanocarriers have the advantages of simple preparation, large specific surface area, high drug loading efficiency and chemical / thermal stability, and are very potential drug delivery carriers. However, some inorganic nanocarriers have very poor biodegradability, which seriously limits their clinical application. Calcium carbonate (CaCO3) is one of the most widely existing minerals in nature, and calcium carbonate nanoparticles have high porosity, biocompatibility, biodegradability, and pH sensitivity, which makes them a candidate for drug delivery carriers. Studies have shown that calcium carbonate has great potential as a carrier for medical applications. SUMMARY

[0004] In view of the above technical problems existing in the prior art, the present application aims to provide a calcium carbonate-based degradable organic-inorganic hybrid nanoparticle and a preparation method thereof, which uses a kind of amphiphilic block copolymer with polyacid modified side chain to encapsulate water-soluble antitumor drug doxorubicin hydrochloride, thereby preparing the hybrid nanoparticle. By encapsulating doxorubicin hydrochloride (DOX) in calcium carbonate-amphiphilic block copolymer, a new organic-inorganic hybrid nanocarrier with high DOX loading, high biocompatibility and biodegradability can be prepared. The present application aims to develop a simple method for preparing hybrid nanoparticles, reduce the toxicity of DOX and improve the anticancer efficacy of DOX.

[0005] The object of the present application is achieved by the following technical solutions:

[0006] The calcium carbonate-based degradable organic-inorganic hybrid nanoparticle is characterized in that it is prepared using calcium carbonate and amphiphilic block copolymer as raw materials, the amphiphilic block copolymer as an organic matrix, and the calcium carbonate as an inorganic matrix. The organic matrix and the inorganic matrix form a calcium carbonate-based hybrid nanoparticle, which encapsulates water-soluble drug doxorubicin hydrochloride. The mass ratio of the organic matrix to the inorganic matrix is 1-2:1, preferably 1.2-1.5:1.

[0007] The preparation method of the calcium carbonate-based degradable organic-inorganic hybrid nanoparticle is characterized by the following steps:

[0008] 1) Add the drug doxorubicin hydrochloride and the copolymer to the calcium chloride aqueous solution, mix at high speed, and prepare an orange-red emulsion A;

[0009] 2) Under high-speed stirring, quickly add the sodium carbonate solution B to the emulsion A, mix, and obtain the calcium carbonate-based hybrid nanoparticle;

[0010] The copolymer is an amphiphilic block copolymer with polyacid side chain modification.

[0011] The preparation method of the calcium carbonate-based degradable organic-inorganic hybrid nanoparticle is characterized in that the concentration of the calcium chloride aqueous solution and the sodium carbonate aqueous solution is 0.08-0.12 mol / L, preferably 0.1 mol / L. The volume ratio of the emulsion A to the solution B is 1:0.8-1.2, and the molar ratio of calcium chloride in the emulsion A to sodium carbonate in the solution B is 1:1-1.2. The mass ratio of the copolymer to the drug doxorubicin hydrochloride is 10:1-30:1, preferably 14-15:1.

[0012] The preparation method of the calcium carbonate-based degradable organic-inorganic hybrid nanoparticle is characterized in that the average particle size of the calcium carbonate-based hybrid nanoparticle is 50-200 nm, and the average drug encapsulation rate of the nanoparticle is 70%-90%.

[0013] The preparation method of the calcium carbonate-based degradable organic-inorganic hybrid nanoparticles is characterized in that the preparation method of the amphiphilic block copolymer with a plurality of carboxyl side chains comprises the following steps:

[0014] The preparation method of the calcium carbonate-based degradable organic-inorganic hybrid nanoparticles is characterized in that the preparation method of the amphiphilic block copolymer with a plurality of carboxyl side chains comprises the following steps:

[0015] S1: under nitrogen protection, using polyethylene glycol monomethyl ether as an initiator, mixing an alkyne-modified aliphatic lactone monomer and a hydrophobic lactone monomer, adding an organic solvent C, and performing reaction at a temperature of 145-155 DEG C; residual water in the reaction system is removed through a water trap device, Sn(Oct)2 is added as a catalyst, and reaction is performed for 45-50 hours; after reaction, the reaction solution is cooled to room temperature, extracted with a dichloromethane-water mixture, and separated; the organic phase is concentrated, the concentrate is redissolved in dichloromethane to form a clear solution, n-hexane is added and stirred slowly to precipitate, and the supernatant is discarded after the supernatant is clarified; the obtained lower precipitate is vacuum-dried to obtain the alkyne-modified amphiphilic block copolymer;

[0016] S2: under nitrogen protection, sodium L-ascorbate is added, the alkyne-modified amphiphilic block copolymer is mixed with an azido small-molecule carboxylic acid, an organic solvent D is added, a copper acetate catalyst is quickly added, and reaction is performed at 45-55 DEG C in the dark for 1-2 days; after reaction, the reaction solution is cooled to room temperature, placed in a dialysis bag, dialyzed with pure water for 2-3 days, and freeze-dried to obtain the amphiphilic block copolymer with a plurality of carboxyl side chains.

[0017] The preparation method of the calcium carbonate-based degradable organic-inorganic hybrid nanoparticles is characterized in that the organic solvent C is toluene, and the organic solvent D is N,N-dimethylformamide.

[0018] The preparation method of the calcium carbonate-based degradable organic-inorganic hybrid nanoparticles is characterized in that the alkyne-modified aliphatic lactone monomer is α-alkynyl-δ-valerolactone, and the hydrophobic lactone monomer is D,L-lactide or caprolactone.

[0019] The preparation method of the degradable organic-inorganic hybrid nanoparticles is characterized in that the molar ratio of the alkyne-modified aliphatic lactone monomer and the hydrophobic lactone monomer is 1.5-2.3:1, and the molar ratio of the alkyne-modified aliphatic lactone monomer and the polyethylene glycol monomethyl ether is 10-60:1.

[0020] The preparation method of the degradable organic-inorganic hybrid nanoparticles is characterized in that the azido small molecule carboxylic acid is 3-azidopropionic acid.

[0021] The preparation method of the degradable organic-inorganic hybrid nanoparticles is characterized in that the mass ratio of the alkyne side chain modified amphiphilic block copolymer, the azido small molecule carboxylic acid, the copper acetate and the sodium L-ascorbate is 1:0.7-1.8:0.03-0.05:0.07-0.1.

[0022] In the specific embodiment of the present application, the copolymer is polyethylene glycol monomethyl ether-poly(alpha-alkynyl propyl-delta-valerolactone)-poly(lactide) copolymer (mPEG-b-P(AVL-co-LA)) or polyethylene glycol monomethyl ether-poly(alpha-alkynyl propyl-delta-valerolactone)-poly(caprolactone) copolymer (mPEG-b-P(AVL-co-CL)).

[0023] The specific structure and synthesis route of mPEG-b-P(AVL-co-LA) and mPEG-b-P(AVL-co-CL) are as follows:

[0024]

[0025] The present application has the following beneficial effects:

[0026] The present application synthesizes a new copolymer, and hydrophilic drug doxorubicin hydrochloride is wrapped in the copolymer by using hydrophobic interaction and electrostatic interaction, so that the encapsulation rate is high and the structure is stable. In addition, the preparation method adopted in the present application is simple and easy to operate, which can not only be suitable for the encapsulation of hydrophilic drugs, but also is conducive to large-scale production. The nanoparticles of the present application are uniform in size, high in drug loading efficiency and good in biocompatibility, and can achieve good application effect, and have great development potential. BRIEF DESCRIPTION OF DRAWINGS

[0027] Figure 1 1a: mPEG-b-P(AVLx-co-LAx) (x:y=1:1) nanomaterial prepared in step 1) of Example 1: 2K H-NMR spectrum. 2K 1

[0028] Figure 2 1b: mPEG-b-P(AVLx-co-LAx) (x:y=1:1) nanomaterial prepared in step 1) of Example 2:​​2K -b-P(AVLx-co-CLy) 2K (x:y = 1 : 1) nanomaterials 1 H-NMR spectra.

[0029] Figure 3 is 2a prepared in step 1) of Example 3: mPEG 5K -b-P(AVLx-co-LAy) 8K (x:y = 1 : 1) nanomaterials 1 H-NMR spectra.

[0030] Figure 4 is 2b prepared in step 1) of Example 4: mPEG 5K -b-P(AVLx-co-LAy) 8K (x:y = 1 : 1) nanomaterials 1 H-NMR spectra.

[0031] Table 1 is the change of particle size and particle size distribution coefficient PDI observed by laser particle size instrument dynamic light scattering instrument Zetasizer (DLS) in Example 6. DETAILED DESCRIPTION

[0032] The application will be further described in conjunction with specific examples, but the scope of protection of the application is not limited thereto.

[0033] Example 1 Preparation of doxorubicin hydrochloride drug nanoparticles

[0034] 1) Preparation of polyethylene glycol monomethyl ether-poly(α-allyl-δ-valerolactone)- poly(lactide) block copolymer (1a)

[0035] Under nitrogen protection, 1.0 g of polyethylene glycol monomethyl ether (average molecular weight 2000), 0.92 g of α-allyl-δ-valerolactone, 0.54 g of D,L-lactide, and 25 mL of toluene were added into a 50 mL two-necked round-bottom flask. The temperature was raised to 150°C, and after removing the residual water in the mixture through a water trap device, 6-7 drops of Sn(Oct)2 catalyst (purity 97%) were added, and the reaction was carried out for 45-50 hours. After the reaction was completed, 200 mL of dichloromethane and 2-3 drops of 0.1 M hydrochloric acid solution were added to quench the reaction. The reaction solution was washed with water for multiple times until the aqueous phase became neutral. The organic phase was dried over anhydrous sodium sulfate, filtered, and concentrated by a rotary evaporator to obtain a brownish yellow oily crude product. The crude product was dissolved in a small amount of dichloromethane, and 500 mL of n-hexane was slowly added under stirring to precipitate the product. After long-term standing until the supernatant was clear, the supernatant was discarded. The precipitation step was repeated three times, and the product was placed in a vacuum drying oven and dried at 40°C overnight to obtain the final product mPEG 2K-b-P(AVLx-co-LAy) 2K (x:y = 1:1).

[0036] Under nitrogen protection, 0.019 g of L-sodium ascorbate was added, 0.20 g of PEG 2K -b-P(AVLx-co-LAy) 2K (x:y = 1:1) was mixed with 0.34 g of 3-azidopropanoic acid, 4 mL of anhydrous THF was added, 0.009 g of catalyst copper acetate was quickly added under nitrogen protection, and the reaction was carried out at 50°C in the dark for 1-2 days; after the reaction was completed, it was cooled to room temperature, 4 mL of water was added, and it was placed in a dialysis bag and dialyzed for 2-3 days; after dialysis, it was freeze-dried to obtain 0.12 g of a white solid, which was the polycarboxyl side chain modified amphiphilic block copolymer PPAL1. Its 1 H-NMR spectrum is shown in Figure 1

[0037] 2) Preparation of nanoparticles

[0038] 0.014 g of PPAL1 and 1.0 mg of doxorubicin hydrochloride were added to 1 mL of 0.1 M calcium chloride solution, and mixed at high speed for 1 hour to prepare an orange-red emulsion A; 1 mL of 0.1 M sodium carbonate solution B was quickly added to emulsion A under high-speed stirring, and mixed for 1 hour to obtain an orange-red nanoemulsion; hydrophilic disposable needle type filter membrane (pore size 200 μm) was used to remove the insoluble suspended matter, and a drug-loaded nanoparticle aqueous solution was obtained. The average particle size was 201 nm, the particle size distribution coefficient PDI was 0.22, and the drug encapsulation efficiency of the nanoparticles was 71%.

[0039] Preparation of doxorubicin hydrochloride drug nanoparticles

[0040] 1) Preparation of polyethylene glycol monomethyl ether-poly(α-allyl-δ-valerolactone)- poly(caprolactone) block copolymer (1a)

[0041] ​Under nitrogen protection, 1.0 g of polyethylene glycol monomethyl ether (average molecular weight 2000), 0.93 g of α-propargyl-δ-valerolactone, 0.45 g of capro-lactone, 25 mL of toluene were added into a 50 mL two-necked round bottom flask, the reaction temperature was 150°C, after removing the residual water in the mixture by a water trap device, 6-7 drops of Sn(Oct)2 catalyst (purity 97%) were added, and the reaction was carried out for 45-50 hours. After the reaction was completed, 200 mL of dichloromethane and 2-3 drops of 0.1 M hydrochloric acid solution were added to quench the reaction, the quenched reaction solution was washed with water for several times until the aqueous phase became neutral. The organic phase was dried over anhydrous sodium sulfate, filtered and concentrated by a rotary evaporator to obtain a brownish yellow oily crude product. The crude product was dissolved in a small amount of dichloromethane, and was slowly added into 500 mL of n-hexane under stirring to precipitate. After long time standing until the supernatant was clear, the supernatant was discarded. The precipitation step was repeated three times, and the product was placed in a vacuum drying oven at 40°C overnight to obtain the final product mPEG 2K -b-P(AVLx-co-CLy) 2K (x:y = 1:1).

[0042] Under nitrogen protection, 0.014 g of L-sodium ascorbate was added, 0.20 g of mPEG 2K -b-P(AVLx-co-CLy) 2K (x:y = 1:1) was mixed with 0.15 g of 3-azidopropanoic acid, 4 mL of anhydrous THF was added, 0.0065 g of catalyst anhydrous copper acetate was quickly added under nitrogen condition, the reaction was carried out at 50°C in the dark for 1-2 days; after the reaction was completed, it was cooled to room temperature, 4 mL of water was added, and the reaction solution was placed in a dialysis bag and dialyzed for 2-3 days, and then it was freeze-dried to obtain 0.18 mg of light yellow solid, which was the amphiphilic block copolymer PPAC2 with polycarboxyl side chain modification. Its 1 H-NMR spectrum is shown in Figure 2 .

[0043] 2) Preparation of nanoparticles

[0044] 0.014 g of PPAC2 and 1.0 mg of doxorubicin hydrochloride were added into 1 mL of 0.1 M calcium chloride solution, and stirred at high speed for 1 hour to prepare an orange-red emulsion A; 1 mL of 0.1 M sodium carbonate solution B was quickly added into the emulsion A under high speed stirring, and mixed for 1 hour to obtain an orange-red nanoemulsion, and then the existing insoluble suspension was removed by using a hydrophilic disposable needle filter membrane (pore size 200 μm) to obtain a drug-loaded nanoparticle aqueous solution. The average particle size was 192 nm, the particle size distribution coefficient PDI was 0.27, and the drug encapsulation rate of the nanoparticles was 77% as tested by a laser dynamic scattering instrument.

[0045] Preparation of doxorubicin hydrochloride drug nanoparticles

[0046] 1) Preparation of poly(ethylene glycol monomethyl ether)-poly(a- propargyl-5-valerolactone)-poly(lactide) block copolymer (1a)

[0047] Under nitrogen protection, 1.0 g of poly(ethylene glycol monomethyl ether) (average molecular weight 5000), 1.4 g of a-propargyl-5-valerolactone, 0.75 g of D,L-lactide, 25 mL of toluene were added into a 50 mL two-necked round bottom flask, the reaction temperature was 150°C, after removing the residual water in the mixture by a water trap device, 6-7 drops of Sn(Oct)2 catalyst (purity 97%) were added, and the reaction was carried out for 45-50 hours. After the reaction was completed, 200 mL of dichloromethane and 2-3 drops of 0.1 M hydrochloric acid solution were added to quench the reaction, and the quenched reaction solution was washed with water for several times until the aqueous phase became neutral. The organic phase was dried over anhydrous sodium sulfate, filtered and concentrated by a rotary evaporator to obtain a brownish yellow oily crude product. The crude product was dissolved in a small amount of dichloromethane, and 500 mL of n-hexane was slowly added under stirring to precipitate the product. After long time standing until the supernatant was clear, the supernatant was discarded. After the precipitation step was repeated three times, the product was placed in a vacuum drying oven and dried at 40°C overnight to obtain the final product mPEG 5K -b-P(AVLx-co-LAy) 8K (x:y = 1:1).

[0048] Under nitrogen protection, 0.019 g of sodium L-ascorbate was added, 0.2 g of mPEG 5K -b-P(AVLx-co-LAy) 8K (x:y = 1:1) was mixed with 0.35 g of 3-azidopropanoic acid, 4 mL of anhydrous THF was added, 0.009 g of catalyst anhydrous copper acetate was quickly added under nitrogen condition, and the reaction was carried out at 50°C in the dark for 1-2 days; after the reaction was completed, it was cooled to room temperature, 4 mL of water was added, and the reaction solution was dialyzed in a dialysis bag for 2-3 days, and then freeze-dried to obtain 0.17 g of pure white solid, which was the amphiphilic block copolymer PPAL3 modified with multiple carboxyl side chains. Its 1 H-NMR spectrum is shown in Figure 3 .

[0049] 2) Preparation of nanoparticles

[0050] 0.014g of PPAL3 and 1.0 mg of doxorubicin hydrochloride were added into 1 mL of 0.1 M calcium chloride solution, stirred at high speed for 1 hour to prepare an orange-red emulsion A; 1 mL of 0.1 M sodium carbonate solution B was quickly added into the emulsion A under high speed stirring, mixed for 1 hour to obtain an orange-red nanoemulsion, and the existing insoluble suspensions were removed by using a hydrophilic disposable needle filter membrane (pore size 200 μm) to obtain a drug-loaded nanoparticle aqueous solution immediately. The average particle size was 77 nm, the particle size distribution coefficient PDI was 0.19, and the nanoparticle encapsulation rate was 82% as tested by a laser dynamic scattering instrument.

[0051] Example 4 Preparation of doxorubicin hydrochloride drug nanoparticles

[0052] 1) Preparation of polyethylene glycol monomethyl ether-poly (α-allyl-δ-valerolactone)- poly (caprolactone) block copolymer (la)

[0053] Under nitrogen protection, 1.5 g of polyethylene glycol monomethyl ether (average molecular weight 5000), 2.4 g of α-allyl-δ-valerolactone, 1.1 g of caprolactone, 25 mL of toluene, and 6-7 drops of Sn (Oct) 2 catalyst (purity 97%) were added into a 50 mL two-necked round-bottom flask, and the reaction temperature was 150°C. After removing the residual water in the mixed solution by a water trap device, the reaction was carried out for 45-50 hours. After the reaction was completed, 200 mL of dichloromethane and 2-3 drops of 0.1 M hydrochloric acid solution were added to quench the reaction, and the quenched reaction solution was washed with water for multiple times until the aqueous phase became neutral. The organic phase was dried over anhydrous sodium sulfate, filtered, and concentrated by a rotary evaporator to obtain a brownish yellow oily crude product. The crude product was dissolved in a small amount of dichloromethane, and the precipitate was separated by slowly adding 500 mL of n-hexane under stirring. After long-term standing until the supernatant was clear, the supernatant was discarded. After the precipitation step was repeated for three times, the product was placed in a vacuum drying oven and dried at 40°C overnight to obtain the final product mPEG 5K -b-P (AVLx-co-CLy) 8K (x:y = 1:1).

[0054] Under nitrogen protection, 0.018 g of L-sodium ascorbate was added, and 0.20 g of mPEG 5K -b-P (AVLx-co-CLy) 8K (x:y = 1:1) was mixed with 0.20 g of 3-azidopropionic acid, 4 mL of anhydrous THF was added, 0.0083 g of catalyst anhydrous copper acetate was quickly added under nitrogen condition, and the reaction was carried out at 50°C in the dark for 1-2 days; after the reaction was completed, the reaction solution was cooled to room temperature, 4 mL of water was added, and the reaction solution was placed in a dialysis bag and dialyzed for 2-3 days. After the dialysis was completed, the reaction solution was freeze-dried to obtain 0.20 mg of light yellow solid, which was the amphiphilic block copolymer PPAC4 with polycarboxyl side chain modification. The 1H-NMR spectrum is shown in Figure 4

[0055] 2) Preparation of nanoparticles

[0056] 0.014 g of PPAC4 and 1.0 mg of doxorubicin hydrochloride were added to 1 mL of 0.1 M calcium chloride solution, mixed at high speed for 1 hour, to prepare an orange-red emulsion A; 1 mL of 0.1 M sodium carbonate solution B was quickly added to the emulsion A under high speed stirring, mixed for 1 hour, to obtain an orange-red nanoemulsion, and the presence of insoluble suspensions was removed by using a hydrophilic disposable needle filter membrane (pore size 200 μm), to obtain a drug-loaded nanoparticle aqueous solution immediately. The average particle size was 85 nm, the particle size distribution coefficient PDI was 0.20, and the nanoparticle encapsulation rate was 89% as tested by a laser dynamic scattering instrument.

[0057] Example 5 Determination of nanoparticle encapsulation rate

[0058] The encapsulation rate of doxorubicin hydrochloride was detected by liquid phase high performance chromatography:

[0059] Chromatographic column: Welch XB-C18

[0060] Mobile phase: acetonitrile / 0.1% trifluoroacetic acid aqueous solution (65 / 25 v:v)

[0061] Detection wavelength 233 nm; flow rate 1.0 mL / min; injection volume 20 μL. A standard solution with a concentration of 1.00 mg / mL was prepared, and dilution solutions with concentrations of 0.75 mg / mL, 0.50 mg / mL, 0.175 mg / mL, 0.10 mg / mL, and 0.01 mg / mL were prepared by using a pipette gun. A series of prodrug standard solutions with different concentrations were detected by HPLC under the above chromatographic conditions, and the peak area of the characteristic peak was used to curve fit the prodrug concentration to establish a regression equation.

[0062] Detection of encapsulation rate: the nanoparticle aqueous solution prepared was added to an equal volume of acetonitrile solution to break the emulsion and dissolve, and the solution obtained by breaking the emulsion was detected by HPLC under the above chromatographic conditions to determine the content of doxorubicin hydrochloride in the drug-loaded nanoparticles.

[0063] Encapsulation rate (%) = amount of drug encapsulated in nanoparticles / total amount of drug input * 100%;

[0064] The average encapsulation rate of the drug-loaded nanoparticles obtained in Examples 1-4 was 70%-90%.

[0065] Example 6 In vitro stability experiment of doxorubicin hydrochloride-containing drug nanoparticles

[0066] ​The drug-loaded nanoparticles prepared in Examples 1-4 were stored in the dark at room temperature. The changes in particle size and PDI were observed by dynamic light scattering instrument Zetasizer (DLS) at the time of preparation, the first day, the third day, and the seventh day, respectively. The changes in particle size are shown in Table 1. As shown in Table 1, the drug-loaded nanoparticles have excellent stability.

[0067] Table 1

[0068]

Claims

1. A biodegradable organic-inorganic hybrid nanoparticle based on calcium carbonate, characterized in that... It uses calcium carbonate and amphiphilic block copolymer as raw materials, with the amphiphilic block copolymer as the organic matrix and calcium carbonate as the inorganic matrix. The calcium carbonate-based hybrid nanoparticles formed by the organic matrix and the inorganic matrix encapsulate the water-soluble drug doxorubicin hydrochloride. The mass ratio of the organic matrix to the inorganic matrix is ​​1~2:

1. The method for preparing biodegradable organic-inorganic hybrid nanoparticles based on calcium carbonate includes the following steps: 1) Add the drug doxorubicin hydrochloride and the copolymer to an aqueous solution of calcium chloride and mix by high-speed stirring to obtain an orange-red emulsion A; 2) Under high-speed stirring, sodium carbonate solution B was rapidly added to emulsion A and mixed to obtain calcium carbonate-based hybrid nanoparticles; The copolymer is an amphiphilic block copolymer modified with a polycarboxylic acid side chain; The preparation method of polycarboxylic acid side-chain modified amphiphilic block copolymer is as follows: polyethylene glycol monomethyl ether is used as an initiator, mixed with alkyne-modified aliphatic lactone monomers and hydrophobic lactone monomers, and the side-chain alkyne-modified amphiphilic block copolymer is obtained by ring-opening polymerization, and then the amphiphilic block copolymer with polycarboxylic acid side chain modified is obtained by click chemical reaction with a small molecule carboxylic acid with carboxyl group. The alkyne-modified aliphatic lactone monomer is α-propargyl-δ-valerolactone, and the hydrophobic lactone monomer is D,L-lactide or caprolactone. The molar ratio of the alkyne-modified aliphatic lactone monomer and the hydrophobic lactone monomer is 1.5~2.3:1, and the molar ratio of the alkyne-modified aliphatic lactone monomer to polyethylene glycol monomethyl ether is 10~60:

1. The azide-based small molecule carboxylic acid is 3-azidopropionic acid.

2. The biodegradable organic-inorganic hybrid nanoparticle based on calcium carbonate as described in claim 1, characterized in that, The mass ratio of the organic matrix to the inorganic matrix is ​​1.2~1.5:

1.

3. The biodegradable organic-inorganic hybrid nanoparticle based on calcium carbonate as described in claim 1, characterized in that... The concentrations of the calcium chloride aqueous solution and the sodium carbonate aqueous solution are both 0.08~0.12 mol / L, the volume ratio of emulsion A to solution B is 1:0.8~1.2, the molar ratio of calcium chloride in emulsion A to sodium carbonate in solution B is 1:1~1.2, and the mass ratio of the copolymer to the drug doxorubicin hydrochloride is 10:1~30:

1.

4. The biodegradable organic-inorganic hybrid nanoparticle based on calcium carbonate as described in claim 3, characterized in that... The concentrations of the calcium chloride aqueous solution and the sodium carbonate aqueous solution are both 0.1 mol / L, and the mass ratio of the copolymer to the drug doxorubicin hydrochloride is 14~15:

1.

5. The biodegradable organic-inorganic hybrid nanoparticle based on calcium carbonate as described in claim 1, characterized in that... The average particle size of the calcium carbonate-based hybrid nanoparticles is 50-200 nm, and the average drug encapsulation efficiency of the nanoparticles is 70%-90%.

6. The biodegradable organic-inorganic hybrid nanoparticle as described in claim 1, characterized in that... The specific preparation method of the amphiphilic block copolymer modified with polycarboxylic acid side chains includes the following steps: S1: Under nitrogen protection, polyethylene glycol monomethyl ether is used as an initiator. Alkyne-modified aliphatic lactone monomers and hydrophobic lactone monomers are mixed and organic solvent C is added. The reaction temperature is 145-155°C. The residual water in the reaction system is removed by a water separator. Sn(Oct)2 catalyst is added and the reaction is carried out for 45-50 hours. After the reaction is completed, the mixture is cooled to room temperature. The reaction solution is extracted with dichloromethane-water mixture, separated, and the organic phase is concentrated. The concentrate is redissolved with dichloromethane to form a clear solution. Hexane is added and stirred slowly to precipitate the precipitate. The precipitate is allowed to stand until the supernatant is clear. The supernatant is discarded, and the lower precipitate is dried under vacuum to obtain the alkyne-modified amphiphilic block copolymer. S2: Under nitrogen protection, add L-ascorbic acid sodium, mix the alkynyl-modified amphiphilic block copolymer with azide-based small molecule carboxylic acid, add organic solvent D, and quickly add copper acetate catalyst. React at 45-55℃ in the dark for 1-2 days. After the reaction is completed, cool to room temperature, put into a dialysis bag and dialyze with pure water for 2-3 days, and freeze-dry to obtain the amphiphilic block copolymer modified with polycarboxyl side chains.

7. The biodegradable organic-inorganic hybrid nanoparticle as described in claim 6, characterized in that... The organic solvent C is toluene; the organic solvent D is N,N-dimethylformamide.

8. The biodegradable organic-inorganic hybrid nanoparticle as described in claim 6, characterized in that... The mass ratio of the alkynyl side-chain modified amphiphilic block copolymer, the azide-based small molecule carboxylic acid, copper acetate, and L-ascorbic acid sodium is 1:0.7~1.8:0.03-0.05:0.07-0.1.

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