A kind of double pH sensitive drug carrier system and preparation method thereof

Abstract

The invention discloses a dual pH-sensitive drug carrier system, which uses H‑MnO loaded with anticancer drug doxorubicin (DOX) 2 Surface modified "valve" chitosan (CHI) to block the pores; then monobenzaldehyde-terminated polyethylene glycol (mPEG‑CHO) was linked to CHI through imine bonds to prepare a dual pH-sensitive drug carrier system DOX @H‑MnO 2 ‑CHI‑PEG. Under the protection of mPEG, the drug carrier system can be "stealth" under normal physiological conditions (pH 7.4) to avoid non-specific phagocytosis by normal cells and prolong its circulation time in the body; while in tumor tissue In a slightly acidic environment (pH‑6.5), the imine bond connecting mPEG and CHI is hydrolyzed and broken, and the protective layer of mPEG falls off, exposing the positively charged CHI, which realizes acid activation and promotes the uptake of the carrier by tumor cells, which contributes to Carriers enter cancer cells; in the more acidic environment (pH‑5.5) inside cancer cells, H‑MnO 2 It can be further degraded to release DOX to kill cancer cells.

Description

technical field

[0001] The invention belongs to the field of drug carriers, and in particular relates to a dual pH-sensitive drug carrier system and a preparation method thereof. Background technique

[0002] In order to improve the defects in chemotherapy and improve the effectiveness of chemotherapy, drug delivery system (DDS) came into being. This is due to the fact that drug carrier systems can release drugs on-demand at specific sites in response to external or internal signals. For example, the drug carrier system includes redox, pH, light, enzyme single stimulus response, dual stimulus response or multiple different stimulus responses and other drug carrier systems.

[0003] The use of pH response to construct drug carrier systems is the most widely used. Polymers that respond to pH generally contain weakly basic or weakly acidic functional groups. Weakly basic functional group - amino (-NH 2 ) can accept a proton and be positively charged under acidic conditions,...

Examples

Embodiment 1

[0050] A preparation method of a double pH-sensitive drug carrier system, specifically comprising the following steps:

[0051] 1. Loading doxorubicin on hollow manganese dioxide and grafting chitosan

[0052] Disperse 20mg chitosan (CHI) in 120mL deionized water, adjust to 5-6 with acetic acid to obtain solution a; 200mg hollow manganese dioxide H-MnO 2 Disperse in 80mL deionized water, add 100mg DOX, and stir vigorously at 25°C for 24h in the dark to obtain solution b; then add solution a dropwise, react at 25°C for 2.5h, centrifuge, wash and dry to obtain grafted chitosan Sugar and doxorubicin-loaded hollow manganese dioxide (DOX@H-MnO 2 -CHI).

[0053] 2. Modification of monobenzaldehyde-terminated polyethylene glycol

[0054] Accurately weigh 200mg of DOX@H-MnO 2 -CHI, ultrasonically dispersed in 50mL aqueous solution, add one or two drops of dilute hydrochloric acid to adjust the pH to 7-8, then add 200mg of mPEG-CHO to dissolve, continue to react at 25°C for 72h, ce...

Embodiment 2

[0060] A method for preparing a composite nano drug carrier system, specifically comprising the following steps: accurately weighing 200 mg of DOX@H-MnO 2 -CHI, ultrasonically dispersed in 50mL of PBS (pH 7.4) phosphate buffer solution, then added 200mg of mPEG-CHO to dissolve, continued reaction at 25°C for 72h, centrifuged, washed and dried to obtain DOX@H-MnO 2 -CHI-PEG.

Embodiment 3

[0062] A method for preparing a composite nano drug carrier system, specifically comprising the following steps: accurately weighing 200 mg of DOX@H-MnO 2 -CHI, ultrasonically dispersed in 100mL of PBS (pH 7.4) phosphate buffer solution, then added 100mg of mPEG-CHO to dissolve, continued to react at 25°C for 72h, centrifuged, washed and dried to obtain DOX@H-MnO 2 -CHI-PEG.

[0063] The detection method of each intermediate product and final product obtained in Example 2-3 is the same as that of Example 1, and it has been verified that the drug carrier system has been successfully prepared, which has dual pH sensitivity and good targeting, and the drug itself has no large Under the gradual acid activation, it can release the drug well and cause the apoptosis of cancer cells. Therefore, the drug carrier system of the present invention has good dual pH sensitivity and high-efficiency targeted drug delivery ability in cancer cells, which can effectively improve drug utilization...

technical field

[0001] The invention belongs to the field of drug carriers, and in particular relates to a dual pH-sensitive drug carrier system and a preparation method thereof. Background technique

[0002] In order to improve the defects in chemotherapy and improve the effectiveness of chemotherapy, drug delivery system (DDS) came into being. This is due to the fact that drug carrier systems can release drugs on-demand at specific sites in response to external or internal signals. For example, the drug carrier system includes redox, pH, light, enzyme single stimulus response, dual stimulus response or multiple different stimulus responses and other drug carrier systems.

[0003] The use of pH response to construct drug carrier systems is the most widely used. Polymers that respond to pH generally contain weakly basic or weakly acidic functional groups. Weakly basic functional group - amino (-NH 2 ) can accept a proton and be positively charged under acidic conditions,...

Examples

Embodiment 1

[0050] A preparation method of a double pH-sensitive drug carrier system, specifically comprising the following steps:

[0051] 1. Loading doxorubicin on hollow manganese dioxide and grafting chitosan

[0052] Disperse 20mg chitosan (CHI) in 120mL deionized water, adjust to 5-6 with acetic acid to obtain solution a; 200mg hollow manganese dioxide H-MnO 2 Disperse in 80mL deionized water, add 100mg DOX, and stir vigorously at 25°C for 24h in the dark to obtain solution b; then add solution a dropwise, react at 25°C for 2.5h, centrifuge, wash and dry to obtain grafted chitosan Sugar and doxorubicin-loaded hollow manganese dioxide (DOX@H-MnO 2 -CHI).

[0053] 2. Modification of monobenzaldehyde-terminated polyethylene glycol

[0054] Accurately weigh 200mg of DOX@H-MnO 2 -CHI, ultrasonically dispersed in 50mL aqueous solution, add one or two drops of dilute hydrochloric acid to adjust the pH to 7-8, then add 200mg of mPEG-CHO to dissolve, continue to react at 25°C for 72h, ce...

Embodiment 2

[0060] A method for preparing a composite nano drug carrier system, specifically comprising the following steps: accurately weighing 200 mg of DOX@H-MnO 2 -CHI, ultrasonically dispersed in 50mL of PBS (pH 7.4) phosphate buffer solution, then added 200mg of mPEG-CHO to dissolve, continued reaction at 25°C for 72h, centrifuged, washed and dried to obtain DOX@H-MnO 2 -CHI-PEG.

Embodiment 3

[0062] A method for preparing a composite nano drug carrier system, specifically comprising the following steps: accurately weighing 200 mg of DOX@H-MnO 2 -CHI, ultrasonically dispersed in 100mL of PBS (pH 7.4) phosphate buffer solution, then added 100mg of mPEG-CHO to dissolve, continued to react at 25°C for 72h, centrifuged, washed and dried to obtain DOX@H-MnO 2 -CHI-PEG.

[0063] The detection method of each intermediate product and final product obtained in Example 2-3 is the same as that of Example 1, and it has been verified that the drug carrier system has been successfully prepared, which has dual pH sensitivity and good targeting, and the drug itself has no large Under the gradual acid activation, it can release the drug well and cause the apoptosis of cancer cells. Therefore, the drug carrier system of the present invention has good dual pH sensitivity and high-efficiency targeted drug delivery ability in cancer cells, which can effectively improve drug utilization...

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