Biomimetic chitosan filler for preventing capsular contracture and preparation method thereof

Abstract

The present invention relates to the technical field of reconstructive plastic surgery and cosmetology, and particularly to a biomimetic chitosan filler for preventing capsular contracture and preparation method thereof. The biomimetic chitosan filler for preventing capsular contracture includes chitosan gel, cross-linked sodium hyaluronate, surfactant, isoosmotic regulator, autologous adipose-derived stem cells, pH adjusting agent and water. The amount of the pH adjusting agent is to adjust a pH value of the chitosan filler to be within a range of 6.5-7.5. The chitosan filler prepared according to the present invention can reduce the inflammation caused by post-operative silica gel exudation, and prevent the occurrence and development of capsular contracture.

Claims

1. A biomimetic chitosan filler for preventing capsular contracture comprising: a chitosan gel, a cross-linked sodium hyaluronate, a surfactant, an isoosmotic regulator, autologous adipose-derived stem cells, a pH adjusting agent and water; wherein an amount of the pH adjusting agent is to adjust a pH value of the biometic chitosan filler to be within a range of 6.5-7.5; wherein the biomimetic chitosan filler has 0.005-10 wt of the chitosan gel, 0.005-10 wt of the cross-linked sodium hyaluronate, 0.5-100 wt of the surfactant, 0.05-50 wt of the isoosmotic regulator, 110.sup.5-110.sup.10 cells/3 mL of the autologous adipose-derived stem cells, pH adjusting agent and a rest amount is water.

2. The biomimetic chitosan filler for preventing capsular contracture of claim 1, wherein the chitosan gel is a hydroxybutyl chitosan gel.

3. The biomimetic chitosan filler for preventing capsular contracture of claim 1, wherein the cross-linked sodium hyaluronate is a cross-linked sodium hyaluronate having a molecular weight of 2.510.sup.3-6.010.sup.3 kDa.

4. The biomimetic chitosan filler for preventing capsular contracture of claim 1, wherein the surfactant is a polyol, the isoosmotic regulator is one or more items selected from the group consisting of sodium chloride, potassium chloride, and magnesium chloride.

5. The biomimetic chitosan filler for preventing capsular contracture of claim 4, wherein the surfactant is one or more items selected from the group consisting of polyethylene glycol, butylene glycol, and tween 80; the isoosmotic regulator is a mixture of sodium chloride and potassium chloride, wherein the sodium chloride accounts for 40-85 wt % of a total amount of the isoosmotic regulator, and the potassium chloride accounts for 15-60 wt % of the total amount of the isoosmotic regulator.

6. The biomimetic chitosan filler for preventing capsular contracture of claim 1, wherein the pH adjusting agent is one or more items selected from the group consisting of boric acid, sodium borate, phosphate buffer, sodium hydroxide, hydrochloric acid, citric acid, and sodium citrate.

7. The biomimetic chitosan filler for preventing capsular contracture of claim 1, wherein the chitosan filler has an osmolality of 270-320 mOsmol/Kg.

8. A preparation method of the biomimetic chitosan filler for preventing capsular contracture of claim 1, comprising the following steps: (1) weighing 40-60 wt of water according to a ratio of a formula; adding the weighted water together with the chitosan gel, the cross-linked sodium hyaluronate, the surfactant, the isoosmotic regulator, and the autologous adipose-derived stem cells to a container according to the ratio of the formula and uniformly stirring to form a mixture; adding the pH adjusting agent to the mixture to adjust the pH value to be within the range of 6.5-7.5; and performing a sterilization; (2) further adding a rest amount of water, then performing proper shaking, sterilization and subpackaging.

9. The preparation method of the biomimetic chitosan filler for preventing capsular contracture of claim 8, wherein in step (1), a stirring speed is in a range of 100-200 rpm; a stirring time is in a range of 3-6 hours; a temperature is in a range of 15-25 C.; and the sterilizations in step (1) and step (2) are both to use a 0.2 m filter membrane to filter and sterilize.

Description

DETAILED DESCRIPTION OF THE INVENTION

Embodiment 1

(1) A biomimetic chitosan filler for preventing capsular contracture includes 10 wt hydroxybutyl chitosan gel, 10 wt cross-linked sodium hyaluronate in molecular weight of 2.510.sup.3-6.010.sup.3 kDa, 0.5 wt polyethylene glycol, 0.02 wt sodium chloride, 0.03 wt potassium chloride, 110.sup.10 autologous adipose-derived stem cells and phosphate buffer, the rest amount is water for injection. The amount of phosphate buffer is to adjust the pH value of the chitosan filler to 7.0, the final volume of chitosan filler is 3 mL, and the biomimetic chitosan filler has an osmolality of 300 mOsmol/Kg.

(2) The preparation method of the above-mentioned chitosan filler is as follows:

(3) (1) 50 wt % water for injection is weighed according to the ratio of formula. The weighted water is added into a container together with the chitosan gel, the cross-linked sodium hyaluronate, the surfactant, the isoosmotic regulator and autologous adipose-derived stem cells according to the ratio of formula. After that, uniform stirring is performed under the conditions of 150 rpm of speed, 5 h of time, 20 C. of temperature. Then pH adjusting agent is added to adjust pH value to 7.0, and 0.2 m filter membrane is used to filter and sterilize.

(4) (2) The rest volume of water for injection is further added, then proper shaking is performed, and 0.2 m filter membrane is used to filter and sterilize, then subpackaging is performed.

Embodiment 2

(5) A biomimetic chitosan filler for preventing capsular contracture includes 0.005 wt hydroxybutyl chitosan gel, 5 wt cross-linked sodium hyaluronate in molecular weight of 2.510.sup.3-6.010.sup.3 kDa, 100 wt mixture of butylene glycol and tween 80, 50 wt magnesium chloride, 110.sup.5 autologous adipose-derived stem cells and boric acid, the rest amount is water for injection. The amount of boric acid is to adjust the pH value of the chitosan filler to 6.5, the final volume of chitosan filler is 3 mL, and the biomimetic chitosan filler has an osmolality of 270 mOsmol/Kg.

(6) The preparation method of the above-mentioned chitosan filler is as follows:

(7) (1) 40 wt % water for injection is weighed according to the ratio of formula. The weighted water is added into a container together with the chitosan gel, the cross-linked sodium hyaluronate, the surfactant, the isoosmotic regulator and autologous adipose-derived stem cells according to the ratio of formula. After that, uniform stirring is performed under the conditions of 200 rpm of speed, 6 h of time, 25 C. of temperature. Then pH adjusting agent is added to adjust pH value to 6.5, and 0.2 m filter membrane is used to filter and sterilize.

(8) (2) The rest volume of water for injection is further added, then proper shaking is performed, and 0.2 m filter membrane is used to filter and sterilize, then subpackaging is performed.

Embodiment 3

(9) A biomimetic chitosan filler for preventing capsular contracture includes 5 wt chitosan gel, 0.005 wt cross-linked sodium hyaluronate in molecular weight of 2.510.sup.3-6.010.sup.3 kDa, 50 wt tween 80, 20 wt potassium chloride, 110.sup.10 autologous adipose-derived stem cells and hydrochloric acid, the rest amount is water for injection. The amount of the hydrochloric acid is to adjust the pH value of the chitosan filler to 7.5, the final volume of chitosan filler is 3 mL, and the biomimetic chitosan filler has an osmolality of 320 mOsmol/Kg.

(10) The preparation method of the above-mentioned chitosan filler is as follows:

(11) (1) 60 wt % water for injection is weighed according to the ratio of formula. The weighted water is added into a container together with the chitosan gel, the cross-linked sodium hyaluronate, the surfactant, the isoosmotic regulator and autologous adipose-derived stem cells according to the ratio of formula. After that, uniform stirring is performed under the conditions of 100 rpm of speed, 3 h of time, 15 C. of temperature. Then pH adjusting agent is added to adjust pH value to 7.5, and 0.2 m filter membrane is used to filter and sterilize.

(12) (2) The rest volume of water for injection is further added, then proper shaking is performed, and 0.2 m filter membrane is used to filter and sterilize, then subpackaging is performed.

Embodiment 4

(13) A biomimetic chitosan filler for preventing capsular contracture includes 1 wt chitosan gel, 1 wt cross-linked sodium hyaluronate in molecular weight of 2.510.sup.3-6.010.sup.3 kDa, 20 wt mixture of polyethylene glycol and butanediol, 5 wt sodium chloride, 110.sup.10 autologous adipose-derived stem cells and sodium citrate, the rest amount is water for injection. The amount of sodium citrate is to adjust the pH value of the chitosan filler to 7.0, the final volume of chitosan filler is 3 mL, and the biomimetic chitosan tiller has an osmolality of 280 mOsmol/Kg.

(14) The preparation method of the above chitosan fillers is as follows:

(15) (1) 50 wt % water for injection is weighed according to the ratio of formula. The weighted water is added into a container together with the chitosan gel, the cross-linked sodium hyaluronate, the surfactant, the isoosmotic regulator and autologous adipose-derived stem cells according to the ratio of formula. After that, uniform stirring is performed under the conditions of 150 rpm of speed, 4 h of time, 18 C. of temperature. Then pH adjusting agent is added to adjust pH value to 7.0, and 0.2 m filter membrane is used to filter and sterilize.

(16) (2) The rest volume of water for injection is further added, then proper shaking is performed, and 0.2 m filter membrane is used to filter and sterilize, then subpackaging is performed.

Comparative Example 1

(17) In this comparative example, the difference from embodiment 1 is that no adipose-derived stem cells are contained, and the specific formula is as follows.

(18) A chitosan filler includes 10 wt hydroxybutyl chitosan gel, 10 wt cross-linked sodium hyaluronate in molecular weight of 2.510.sup.3-6.010.sup.3 kDa, 0.5 wt polyethylene glycol, 0.02 wt sodium chloride, 0.03 wt potassium chloride and phosphate buffer, the rest amount is water for injection. The amount of phosphate buffer is to adjust the pH value of the chitosan filler to 7.0, the final volume of chitosan filler is 3 mL.

Comparative Example 2

(19) In this comparative example, the difference from embodiment 1 is that no adipose-derived stem cells and chitosan are contained, and the specific formula is as follows.

(20) A filler includes 10 wt cross-linked sodium hyaluronate in molecular weight of 2.510.sup.3-6.010.sup.3 kDa, 0.5 wt polyethylene glycol, 0.02 wt sodium chloride, 0.03 wt potassium chloride and phosphate buffer, the rest amount is water for injection. The amount of the phosphate buffer is to adjust the value of the chitosan filler to 7.0, the final volume of chitosan filler is 3 mL.

Animal Experiment

(21) 1. Experimental Method:

(22) Eighteen female SD rats were chosen as subjects for the experiment, and were randomly divided into three groups i.e. group A, group B, and group C. 1 wt % amobarbital sodium was injected into the rats at abdominal cavity for anesthesia at 70 mg/kg. Longitudinal incisions with length of 2 cm were respectively made on both sides of the back midline of the SD rats at a position 1 cm apart from the midline, and symmetrical cavities were formed under the latissimus dorsi by stripping. A 10 ml round silicone gel prosthesis (produced by Beijing Research & Design institute of Rubber Products) were placed under the latissimus dorsi on each side of the rats. The left side of each rat was the experimental group, the right side of each rat was the control group. In group A, the biomimetic chitosan filler prepared in embodiment 1 was injected into the left stripping cavity of rats, and the right side was untreated. In group B, the chitosan gel without adipose-derived stem cells prepared in comparative example 1 was injected into the left stripping cavity of rats, and the right side was untreated. In group C, the sodium hyaluronate gel without chitosan and stem cells prepared in comparative example 2 was injected into the left stripping cavity of rats, and the right side was untreated. At 4, 8 and 12 weeks after surgery, the capsules were excised and examined by histological examination by groups, and the thickness and the areal density of type I and type III collagen of the capsules were measured. The data was represented by xs, and the t-test of paired data was performed using Spss11.0 statistical software.

(23) 2. Experimental Results:

(24) TABLE-US-00001 TABLE 1 The capsule thickness comparison on the experimental side and control side at 4 weeks after surgery collagen experimental control group type side(m) side(m) P value A type I 0.063 0.007 0.198 0.063 P < 0.01 type III 0.089 0.009 0.208 0.033 P < 0.01 B type I 0.098 0.011 0.179 0.066 P < 0.01 type III 0.099 0.007 0.191 0.067 P < 0.01 C type I 0.187 0.028 0.189 0.083 P > 0.05 type III 0.179 0.006 0.177 0.036 P > 0.05

(25) TABLE-US-00002 TABLE 2 The capsule thickness comparison on the experimental side and control side at 8 weeks after surgery collagen experimental control group type side(m) side(m) P value A type I 0.031 0.045 0.198 0.063 P < 0.01 type III 0.023 0.005 0.208 0.033 P < 0.01 B type I 0.074 0.004 0.179 0.066 P < 0.01 type III 0.077 0.007 0.191 0.067 P < 0.01 C type I 0.158 0.004 0.189 0.083 P > 0.05 type III 0.165 0.003 0.177 0.036 P > 0.05

(26) TABLE-US-00003 TABLE 3 The capsule thickness comparison on the experimental side and control side at 12 weeks after surgery collagen experimental control group type side(m) side(m) P value A type I 0.007 0.006 0.198 0.063 P < 0.01 type III 0.005 0.008 0.208 0.033 P < 0.01 B type I 0.029 0.015 0.179 0.066 P < 0.01 type III 0.038 0.006 0.191 0.067 P < 0.01 C type I 0.133 0.007 0.189 0.083 P > 0.05 type III 0.139 0.008 0.177 0.036 P > 0.05

(27) As can be seen from Tables 1-3, comparing group A and group B, the addition of adipose-derived stem cells in group A can reduce inflammation caused by silicone exudation after surgery, and has a significant effect on the prevention of capsular contracture. Comparing group B and group C, since chitosan can play a good role in physical barrier, it can block inflammation-related receptors, and inhibit inflammation.

(28) For those skilled in the art, various corresponding changes and variations may be derived according to the foregoing technical solutions and concepts, and all of these changes and variations should fall within the protection scope of the appended claims of the present invention.