Disclosure of Invention
In order to solve the problems in the prior art, one of the objects of the present invention is to provide a functional dressing having both effects of accelerating wound healing and reducing scarring.
In order to achieve the purpose of the invention, the technical scheme of the invention is as follows:
a functional dressing comprising: a fiber layer having piezoelectric properties and a silicone layer, the fiber layer being composited with the silicone layer, the silicone layer being for contact with an object to be administered; the fiber layer is a polyvinylidene fluoride fiber membrane or a polyvinylidene fluoride-polysiloxane blended fiber membrane.
According to the invention, the specific fiber layer with piezoelectric property is compounded with the organic silicon layer, and the organic silicon layer is in complete covering contact with the surface of an application object (wound), so that the functional dressing can simultaneously play the effects of accelerating wound healing, preventing and reducing scars, has a simple structure, does not need to be matched with other special equipment, and meets the pursuit of patients on comprehensive treatment effect of the wound.
Subjects (wounds) to which they are applied include, but are not limited to, traumatic skin injuries, incisions, abrasions, burns and surgical wounds.
In the functional dressing of the invention, the organic silicon layer comprises one or more of silicone resin, silicone rubber and silicon foam; the viscosity of the coating-4 cup of the silicone resin is 20-100 s; the dynamic viscosity of the silicone rubber is 500-5000 mPa & s; the dynamic viscosity of the silicon foam is 500-10000 mPa & s.
Preferably, the viscosity of the silicone resin is 68s of coating-4 cup viscosity, the dynamic viscosity of the silicone rubber is 3450mPa & s, and the dynamic viscosity of the silicone foam is 8500mPa & s, so that the organic silicon layer and the fiber layer are easy to prepare in a composite manner, are tightly and firmly combined, and simultaneously, the effects of accelerating wound healing and resisting scars are achieved.
In the functional dressing, the thickness of the fiber layer is 0.05-1 mm, preferably 0.08-0.1 mm; the thickness of the organic silicon layer is 0.5-5 mm, preferably 0.8-1.2 mm.
In the functional dressing, the Shore A hardness of the cured organic silicon layer is 30-80, preferably 50-70, and more preferably 60.
Researches show that when the organic silicon layer adopts the thickness and the hardness, the strength of the fiber layer can be improved, the elongation rate of the fiber layer is not influenced, the integral flexibility and the compliance of the functional dressing are ensured, the micro-current generation and the micro-current size influence on the PVDF fiber film and the PVDF-PDMS blended fiber film are small while the anti-scar effect of the organic silicon layer is ensured, and the effect of accelerating wound healing is ensured.
Preferably, when the thickness of the fiber layer is 0.1mm, the thickness of the silicone layer is 0.8mm, and the shore a hardness is 60, so that the comprehensive effect of the invention can be better exerted.
One or more additives including, but not limited to, therapeutic agents, antimicrobial agents, medicinal pigments, dyes, and the like, may also be included in the silicone layer of the present invention.
The silicone layer of the present invention may be disposed on only one side of the fiber layer facing the object to be applied (i.e., the fiber layer is disposed on the silicone layer), or may be disposed on both the upper and lower sides of the fiber layer, thereby further protecting the structure of the fiber layer from external contamination.
In the functional dressing of the present invention, the fibrous layer is encapsulated in the silicone layer.
The invention wraps the four sides of the fiber layer in the organic silicon layer in a packaging manner to form the closed dressing, so that the fiber layer can be better isolated from external pollution, the structure of the fiber layer can be more comprehensively protected, the piezoelectric property of the fiber layer is prevented from being disturbed and damaged due to pollution or structural change, the comprehensive performance of the functional dressing is further ensured, the fiber layer can be suitable for repeated application, and the service life is prolonged.
In the functional dressing, the mass ratio of the polyvinylidene fluoride to the polysiloxane in the polyvinylidene fluoride-polysiloxane blended fiber film is (3-5): 1, preferably 4: 1.
researches show that the blended fiber membrane prepared by mixing polyvinylidene fluoride and polysiloxane according to a specific ratio has excellent mechanical property, improved piezoelectric property, more ideal comprehensive effects of accelerating wound healing and reducing scars, and particularly when the mass ratio of polyvinylidene fluoride to polysiloxane is 4: 1 hour, the cicatrix-resisting effect is good, and the wound surface is healed more quickly.
In the functional dressing, the molecular weight of polyvinylidene fluoride is 30-100 ten thousand; the molecular weight of the polysiloxane is 60-200 ten thousand.
It is another object of the present invention to provide a simple and efficient method for preparing the above functional dressing.
The method of the present invention for preparing the above functional dressing comprises steps (1), (2) and (4) or comprises steps (1), (3) and (4):
(1) dissolving polyvinylidene fluoride in a first volatile organic solvent to obtain a first spinning solution;
(2) performing electrostatic spinning on the first spinning solution to obtain the polyvinylidene fluoride fiber membrane;
(3) dissolving polysiloxane in a second volatile organic solvent to obtain a second spinning solution, mixing the first spinning solution and the second spinning solution to obtain a blended spinning solution, and performing electrostatic spinning on the blended spinning solution to obtain the polyvinylidene fluoride-polysiloxane blended fiber membrane;
(4) and compounding the organic silicon layer on the surface of the polyvinylidene fluoride fiber membrane or the polyvinylidene fluoride-polysiloxane blended fiber membrane.
The invention can simply and effectively prepare the fiber layer with piezoelectric property in an electrostatic spinning mode. The fiber layer can also be prepared by one or more of a centrifugal spinning technology, a hot-melt spinning technology, a melt electrospinning technology and a 3D printing technology.
In the method of the invention, the first volatile organic solvent is one or more of N, N-dimethylformamide, dimethyl sulfoxide and N-methylpyrrolidone, preferably N, N-dimethylformamide; the second volatile organic solvent is one or more of tetrahydrofuran, acetone and toluene, and is preferably tetrahydrofuran.
In the method of the present invention, the mass concentration of the polyvinylidene fluoride in the first volatile organic solvent is 20 to 50%; the mass concentration of the polysiloxane in the second volatile organic solvent is 30-50%.
Preferably, when the first volatile organic solvent is N, N-dimethylformamide and the second volatile organic solvent is tetrahydrofuran, a final product with better comprehensive performance can be obtained.
According to the invention, through specially selecting the concentrations of the volatile organic solvent and the polymer in the spinning solution, the spinning efficiency is improved in the subsequent electrostatic spinning, and the electric spinning with uniform properties is obtained, so that the finally obtained functional dressing product has good consistency, and the comprehensive performance is better exerted. Particularly, when the PVDF-PDMS blended spinning solution is prepared, the mixing dispersibility of the PVDF-PDMS blended spinning solution and the blended spinning solution is influenced by the selection of different solvents and concentrations, the PVDF-PDMS blended spinning solution and the blended spinning solution prepared by the method are uniformly dispersed, the piezoelectric synergistic effect of the obtained blended fiber membrane is uniform, and the stable performance of the functional dressing is further ensured.
In the method of the present invention, the conditions of the electrospinning in the steps (2) and (3) are as follows: the spinning voltage is 8-12 kV, the spinning propulsion speed is 1.5-2.5 mL/h, the receiving distance is 18-22 cm, the inner diameter of a spinning needle is 0.6-1.0 mm, and the spinning temperature is 0-40 ℃.
The invention optimizes the electrostatic spinning conditions aiming at the preparation of a specific fiber layer, so that the obtained fiber film has uniform property, uniform pores and good flexibility and strength, and further the finally prepared functional dressing has good air permeability, good product consistency, good effects of promoting wound healing and preventing scars, easy application and long service life.
Preferably, the conditions of the electrostatic spinning are as follows: the spinning voltage is 10kV, the spinning propelling speed is 2mL/h, the receiving distance is 20cm, the inner diameter of a spinning needle is 0.8mm, and the spinning temperature is 20-30 ℃, so that the comprehensive effect of the functional dressing is better realized.
In the invention, the polyvinylidene fluoride is dissolved in the first volatile organic solvent in an oil bath at 0-80 ℃, preferably 50 ℃, so as to better promote dissolution and dispersion and ensure the performance of the final product.
In the invention, the compounding mode of the fiber layer and the organic silicon layer is specifically as follows: casting one or more of silicon resin, silicon rubber and silicon foam into a mould fixed with a fiber layer or directly coating the mixture on the fiber layer, and curing by hydrogen silicon addition or dealcoholization condensation under the heating and vulcanizing condition to obtain the functional dressing.
The invention also provides application of the functional dressing or the method in preparation of an article for tissue repair.
The tissue repair product can be a bandage, a wound plaster, a wound repair sheet, an artificial skin and the like.
The invention has the beneficial effects that:
the functional dressing provided by the invention comprises the PVDF fiber film or PVDF-PDMS blended fiber film with excellent piezoelectricity and the organic silicon layer compounded with the fiber layer, and can play a role in stimulating the wound surface to accelerate healing and reducing scar generation in the wound surface accelerating healing process by providing micro-current. The micro-current can be generated in a portable form of finger pressing, stretching or sound waves and the like, and the functional dressing does not need to be charged by special charging equipment, so that the use is convenient. In addition, the functional dressing fiber layer is tightly and firmly combined with the organic silicon layer, has good air permeability and biocompatibility, ideal tensile property and strength, easy application, repeated use and long service life.
The preparation method of the functional dressing is simple and convenient, the production efficiency is high, the product quality is easy to control, the uniformity is good, and the comprehensive performance of the functional dressing can be ensured.
Detailed Description
Preferred embodiments of the present invention will be described in detail with reference to the following examples. It is to be understood that the following examples are given for illustrative purposes only and are not intended to limit the scope of the present invention. Various modifications and alterations of this invention will become apparent to those skilled in the art without departing from the spirit and scope of this invention.
The experimental procedures used in the following examples are all conventional procedures unless otherwise specified. Materials, reagents and the like used in the following examples are commercially available unless otherwise specified.
Example 1
PVDF powder (molecular weight: 55 ten thousand) was dissolved in N, N-dimethylformamide at 50 ℃ in an oil bath and stirred to obtain a uniform and transparent solution (first spinning solution) having a mass concentration of 25%, 5mL of the above spinning solution was extracted with a 10mL syringe and subjected to electrostatic spinning, and the fiber yarn was taken up into a film-like structure to obtain a fiber film having a thickness of 0.08 mm. The electrostatic spinning parameters are as follows: the spinning voltage is 10kV, the spinning advancing speed is 2mL/h, the receiving distance is 20cm, the inner diameter of a spinning needle is 0.8mm, the spinning temperature is 25 ℃, and the receiving time is 2 h. And (3) smearing and packaging the prepared fiber membrane with liquid silicone resin (80 parts of 1053 silicone resin of Zhonghao Chen photochemical research institute Co., Ltd. +18 parts of GY209-3 hydroxy silicone oil of Zhonghao Chen photochemical research institute Co., Ltd. +2 parts of KH550 of Shandong Qufufu chemical corporation Co., Ltd.; viscosity of coating-4 cups is 68s, Shore A hardness after curing is 50) to obtain a functional dressing with thickness of 1.2 mm.
Example 2
PDMS (silicon organic silicon Limited RTV108,molecular weight 100 ten thousand, Jiangxi Lanxing starfire) is dissolved in Tetrahydrofuran (THF) and stirred at room temperature to obtain a uniform and transparent solution (second spinning solution) with the mass concentration of 45%, PVDF powder (molecular weight 55 ten thousand) is dissolved in N, N-dimethylformamide in an oil bath at 50 ℃ and stirred to obtain a uniform and transparent solution (first spinning solution) with the mass concentration of 30%. And mixing the prepared two polymer solutions (a first spinning solution and a second spinning solution) according to a PVDF/PDMS mass ratio of 4: 1, and magnetically stirring the mixed solution at room temperature for 2 hours to obtain uniform and transparent spinning solution (blended spinning solution). And (3) drawing 5mL of the mixed spinning solution by using a 10mL syringe to carry out electrostatic spinning, and receiving the fiber yarns into a film-shaped structure to obtain a blended fiber film with the thickness of 0.1 mm. The electrostatic spinning parameters are as follows: the spinning voltage is 10kV, the spinning advancing speed is 2mL/h, the receiving distance is 20cm, the inner diameter of a spinning needle is 0.8mm, the spinning temperature is 25 ℃, and the receiving time is 2 h. The prepared blended fiber membrane is cast and packaged in a mould by using liquid silicone rubber (GXJ-2 silicone rubber, viscosity of 3450mPa & s, Shore A hardness of 60 after curing) to obtain a functional dressing with the thickness of 0.8 mm.
Example 3
PDMS (silicon rubber (RTV 108,molecular weight 100 ten thousand, produced by Jiangxi Lanxingshuo organosilicon Co., Ltd.) is dissolved in tetrahydrofuran, and stirred at room temperature to obtain a uniform and transparent solution with the mass concentration of 50%, and PVDF powder (molecular weight 55 ten thousand) is dissolved in N, N-dimethylformamide in an oil bath at 50 ℃ and stirred to obtain a uniform and transparent solution with the mass concentration of 25%. And (3) mixing the prepared two polymer solutions according to the mass ratio of PVDF/PDMS of 5: 1, and magnetically stirring the mixed solution at room temperature for 2 hours to obtain uniform and transparent spinning solution. And (3) drawing 5mL of the mixed spinning solution by using a 10mL syringe to carry out electrostatic spinning, and receiving the fiber yarns into a film-shaped structure to obtain a blended fiber film, wherein the thickness of the blended fiber film is 0.1 mm. The electrostatic spinning parameters are as follows: the spinning voltage is 10kV, the spinning advancing speed is 2mL/h, the receiving distance is 20cm, the inner diameter of a spinning needle is 0.8mm, the spinning temperature is 25 ℃, and the receiving time is 2 h. The prepared blended fiber membrane is packaged in a mould by using liquid silicone rubber (GXJ-2 silicone rubber, viscosity of 3450mPa & s, Shore A hardness of 50 after curing) to obtain a functional dressing with the thickness of 0.8 mm.
Example 4
PDMS (silicon rubber (RTV 108,molecular weight 100 ten thousand, produced by Jiangxi Lanxingshuo organosilicon Co., Ltd.) is dissolved in tetrahydrofuran, and stirred at room temperature to obtain a uniform and transparent solution with a mass concentration of 45%, and PVDF powder (molecular weight 55 ten thousand) is dissolved in N, N-dimethylformamide in an oil bath at 50 ℃ and stirred to obtain a uniform and transparent solution with a mass concentration of 35%. And (3) mixing the prepared two polymer solutions according to the mass ratio of PVDF/PDMS of 5: 1, and magnetically stirring the mixed solution at room temperature for 2 hours to obtain uniform and transparent spinning solution. And (3) drawing 5mL of the mixed spinning solution by using a 10mL syringe to carry out electrostatic spinning, and receiving the fiber yarns into a film-shaped structure to obtain a blended fiber film, wherein the thickness of the blended fiber film is 0.1 mm. The electrostatic spinning parameters are as follows: the spinning voltage is 10kV, the spinning advancing speed is 2mL/h, the receiving distance is 20cm, the inner diameter of a spinning needle is 0.8mm, the spinning temperature is 25 ℃, and the receiving time is 2 h. The prepared liquid silicone resin for the blended fiber membrane (Zhonghao Chen optical chemical research institute Co., Ltd 1053 silicone resin 80 parts +18 parts of Zhonghao Chen optical chemical research institute Co., Ltd GY209-3 hydroxy silicone oil +2 parts of Shandong Qufu chemical Co., Ltd KH550. coating-4 cup viscosity 68s, Shore A hardness after curing 68) is packaged in a mold to obtain the functional dressing with the thickness of 1.0 mm.
Example 5
PDMS was dissolved in tetrahydrofuran and stirred at room temperature to obtain a homogeneous and transparent solution with a mass concentration of 35%, and PVDF powder (molecular weight 55 ten thousand) was dissolved in N, N-dimethylformamide in a 50 ℃ oil bath and stirred to obtain a homogeneous and transparent solution with a mass concentration of 45%. And (3) mixing the prepared two polymer solutions according to the mass ratio of PVDF/PDMS (polyvinylidene fluoride/polydimethylsiloxane) of 3: 1, and magnetically stirring the mixed solution at room temperature for 2 hours to obtain uniform and transparent spinning solution. And (3) drawing 5mL of the mixed spinning solution by using a 10mL syringe to carry out electrostatic spinning, and receiving the fiber yarns into a film-shaped structure to obtain a blended fiber film, wherein the thickness of the blended fiber film is 0.1 mm. The electrostatic spinning parameters are as follows: the spinning voltage is 10kV, the spinning advancing speed is 2mL/h, the receiving distance is 20cm, the inner diameter of a spinning needle is 0.8mm, the spinning temperature is 25 ℃, and the receiving time is 2 h. The prepared blended fiber membrane is packaged in a mould by using liquid silicone rubber (GXJ-2 silicone rubber, viscosity of 3450mPa & s, Shore A hardness of 50 after curing) to obtain a functional dressing with the thickness of 0.8 mm.
Example 6
PVDF powder (molecular weight: 55 ten thousand) was dissolved in N, N-dimethylformamide in an oil bath at 50 ℃ under stirring to give a homogeneous and transparent solution having a mass concentration of 35%, 5mL of the above spinning solution was extracted with a 10mL syringe to carry out electrostatic spinning, and the fibers were collected into a film-like structure to give a fiber film having a thickness of 0.08 mm. The electrostatic spinning parameters are as follows: the spinning voltage is 10kV, the spinning advancing speed is 2mL/h, the receiving distance is 20cm, the inner diameter of a spinning needle is 0.8mm, the spinning temperature is 25 ℃, and the receiving time is 2 h. The prepared fiber membrane is coated and packaged with liquid silicone rubber (GXJ-2 silicone rubber, viscosity 3450mPa · s, Shore A hardness after curing is 50, Miao Chen photochemical research institute Co., Ltd.) to obtain a functional dressing with the thickness of 1.2 mm.
Example 7
PVDF powder (molecular weight: 55 ten thousand) was dissolved in N, N-dimethylformamide at 50 ℃ in an oil bath and stirred to obtain a uniform and transparent solution having a mass concentration of 30%, 5mL of the above spinning solution was extracted with a 10mL syringe to carry out electrostatic spinning, and the fiber yarn was taken up into a film-like structure to obtain a fiber film having a thickness of 0.08 mm. The electrostatic spinning parameters are as follows: the spinning voltage is 10kV, the spinning advancing speed is 2mL/h, the receiving distance is 20cm, the inner diameter of a spinning needle is 0.8mm, the spinning temperature is 25 ℃, and the receiving time is 2 h. The prepared fiber membrane is packaged in a mould by using liquid silicon foam (commercial Taya electronic, TY640, viscosity of the liquid silicon foam is 8500mPa & s, Shore A hardness is 70 after solidification without a foaming agent) to obtain a functional dressing with the thickness of 1.2 mm.
Comparative example 1
The wound dressing (PU/PVDF electrospun membrane as a functional wound dressing) was prepared according to the method of example 7 in chinese patent application CN 102861355A.
Comparative example 2
A functional dressing was prepared in the same manner as in example 2 of the present invention, except that: the functional dressing does not contain the blended fiber membrane and only comprises a silicon rubber layer.
Experimental example 1
An external force (F) is applied to the PVDF fiber membrane prepared in example 1 and the PVDF-PDMS blended fiber membrane prepared in example 2 in a finger pressing mode respectively, the output voltage is measured, the schematic diagram of the test method is shown in figure 1, and the voltage waveform obtained is shown in figure 2. By comparing the output voltages of the PVDF fiber membrane and the PVDF-PDMS blended fiber membrane, the piezoelectric property of the fiber membrane mixed with PDMS is improved.
Experimental example 2
The functional dressings of examples 1 to 7 and comparative examples 1 to 2 after pretreatment (soaking in 70% alcohol solution for 60 minutes and then in physiological saline for 4 hours) were subjected to the dorsal skin wound repair test of SD rats: 30 SD rats (purchased from the center of laboratory animals of southwest medical university, weighing 15-20 g and age 60-70 days) are numbered, circular full-layer skin with the diameter of 1cm is cut off from the backs of the SD rats respectively, each functional dressing is completely covered and attached to the wound surface of the SD rat with the corresponding number, one side of the organic silicon layer is directly contacted with the wound surface, the dressing is replaced once every 7 days, and the wound situation is continuously observed. Recording the recovery time of the wound surface for half, the complete recovery time of the wound surface, the size of the scar and the color of the scar. The test results are shown in Table 1.
TABLE 1 test results
As can be seen from table 1, compared with comparative example 1, the functional dressing of the embodiment of the present invention has significantly small wound scar and light color after the wound of SD rat is healed; the healing speed is greatly improved compared with comparative example 2.
Although the invention has been described in detail hereinabove with respect to a general description and specific embodiments thereof, it will be apparent to those skilled in the art that modifications or improvements may be made thereto based on the invention. Accordingly, such modifications and improvements are intended to be within the scope of the invention as claimed.