CN108619562B

CN108619562B - Skin chip for wound repair and manufacturing method thereof

Info

Publication number: CN108619562B
Application number: CN201810500447.3A
Authority: CN
Inventors: 贺永; 谢超淇; 高庆; 傅建中
Original assignee: Zhejiang University ZJU
Current assignee: Zhejiang University ZJU
Priority date: 2018-05-23
Filing date: 2018-05-23
Publication date: 2020-08-28
Anticipated expiration: 2038-05-23
Also published as: CN108619562A

Abstract

The invention discloses a skin chip for wound repair, which comprises a matrix made of gel materials, wherein a micro-pipeline for liquid to flow is arranged in the matrix, and the micro-pipeline is provided with an outlet and an inlet which are positioned on the matrix. The invention also discloses a preparation method of the skin chip. The shape of the skin chip can be produced in a customized manner according to the shape of the wound, and the skin chip contains an internal channel which is used as a nutrition supply system, so that nutrition is provided for transplanted cells, waste liquid absorbed from the wound is taken away, and the recovery of the wound is facilitated. The internal environment of the chip can be used for the growth and spreading of transplanted cells, and the step of spraying the cells on the surface of the wound is omitted. The remaining interface of the chip nutrition channel can conveniently supply and replace nutrient solution without influencing the daily activities of patients. After the cells are fused with the new skin of the wound, the skin chip substrate can be slowly degraded, the wound can be repaired, and an additional chip stripping step is not needed.

Description

Skin chip for wound repair and manufacturing method thereof

Technical Field

The invention belongs to the technical field of medical supplies, and particularly relates to a skin chip for wound repair and a manufacturing method thereof.

Background

Currently, many burn patients transplant skin that is healthy skin cells from body parts that do not themselves burn. In addition to this, there are artificial skin and skin donations, but both of these usually trigger immune rejection. Severely burned patients die within weeks if not promptly given a skin graft, which often leaves deep scars. The spraying of skin cells is a breakthrough of burn treatment technology, the cells sprayed by a biological printer contain immature stem cells, the skin cells can be fused with surrounding skin, and scars left by burn can be avoided if the burn can be cured within 2 to 3 weeks. However, since tissue structures such as autologous cells and blood vessels in the wound are necrotic, the sprayed cells cannot be supplied with nutrients and are difficult to survive, and the applicability of the skin spraying technique is limited.

The gel has smooth surface, good biocompatibility and strong water absorption capacity, can generate repeated hydration when contacting with tissues, absorbs moisture in the tissues into the dressing, can continuously absorb exudate of a wound surface, then forms gel, and can not be adhered when being replaced. The hydrogel dressing can be tightly adhered to uneven wound surfaces, so that the opportunity of bacterial breeding is reduced, the wound surfaces are prevented from being infected, the generation of new vessels is accelerated, and the growth of epithelial cells is promoted.

The gel can be used as a dressing to provide an initial environment suitable for the growth of cells of a wound, but due to the lack of a nutrient supply system, transplanted cells can only grow in a short period of time and are easy to die due to the unavailable nutrient supply in a long period of time, and most gel medical dressings on the market have no customized shapes aiming at various wounds, so that the fitting effect of the dressing is reduced. In addition, single sodium alginate, polysaccharide and the like are used as biological hydrogel, the biocompatibility is not good, contacted cells cannot be well expressed and spread, GelMA (gelatin-methyl methacrylate) has better biocompatibility, but the formability and the mechanical property are not as good as those of alginate, and the gel can achieve better biocompatibility and mechanical property by mixing a plurality of gels according to a specific proportion and can be used as a substrate material of a biological activity skin chip embedded with cells.

Disclosure of Invention

The invention aims to solve the problem that skin sprayed on a wound part is difficult to survive in the background technology, and provides a skin chip for wound repair.

The invention also provides a method for manufacturing the skin chip for wound repair, the method has simple process, the skin chip attached to the profile of the wound can be freely customized according to the actual shape of the wound, the use is convenient, the implementation is simple, the adoption of the chip is beneficial to the growth of transplanted cells and the wound healing is accelerated, and the skin chip can be slowly degraded along with the growth of the cells without an additional stripping step.

A skin chip for wound repair comprises a matrix made of gel material, wherein the matrix is internally provided with a micro-pipeline for liquid to flow, and the micro-pipeline is provided with an outlet and an inlet which are positioned on the matrix.

Preferably, the substrate has a profile configuration conforming to the wound surface. By adopting the technical scheme, the skin chip can be ensured to be more attached to the wound surface.

Preferably, the matrix of the invention can contain one or two of bacteriostatic anti-infection materials and growth factors for promoting wound healing.

Preferably, the matrix of the present invention may further comprise skin graft cells.

A method for preparing a skin chip for wound repair according to any one of the above technical solutions, comprising the steps of:

(1) establishing a three-dimensional model of the skin chip according to the actual shape of the wound of the patient;

(2) preparing a material for manufacturing the skin chip;

(3) manufacturing a skin chip with a micro-channel for liquid to flow through by using a rapid manufacturing method;

wherein the step (1) and the step (2) are not limited in sequence.

Preferably, the rapid manufacturing method is selected from a 3D printing method, a sacrificial layer manufacturing casting method. When the 3D printing method is selected, in the step (1), after the three-dimensional model of the skin chip is established, slicing of the three-dimensional model is completed through computer slicing software, and finally 3D printing path data of the skin chip is obtained and printed through the existing 3D printing equipment; for example, for printing a micro-pipeline structure, a coaxial double-nozzle structure embedded inside and outside can be adopted for direct printing. When the sacrificial layer manufacturing casting method is selected, in step (1), a mold and the manufacturing of the sacrificial layer material are manufactured according to the constructed three-dimensional model.

The gel material is selected, so that the biocompatibility of the skin grafting cell is ensured, secondary damage to wounds is avoided, and meanwhile, the nutrition supply, the medicine supply and the like to the skin grafting cells can be smoothly realized. The gel material can be polysaccharide, gelatin, matrigel, GelMA (gelatin-methyl methacrylate) gel, alginate, and the mixture of the above gel materials. More preferably, the gel material is a mixture of GelMA gum and alginate or a mixture of GelMA gum, alginate and gelatin. By adopting the gel mixture, the advantage of good biocompatibility of GelMA (gelatin-methyl methacrylate) is kept, and the mechanical property of the gel matrix is ensured. The invention can reach better biocompatibility and mechanical property by mixing a plurality of gels according to a specific proportion, and can be used as a substrate material of a biological activity skin chip embedded with cells.

When the mixed gel of GelMA glue and alginate is selected, in the material preparation stage of the skin chip, 1-4% of sodium alginate aqueous solution in mass concentration can be mixed with GelMA, the mass volume ratio of the sodium alginate in the mixed solution after mixing is 1-2%, and the mass volume ratio of GelMA is 5-15%. Finally, curing can be carried out by simultaneous printing with calcium salts or by light irradiation.

When the gel material is a mixture of GelMA gel, alginate and gelatin, GelMA and a gelatin aqueous solution with the mass concentration of 1-2% can be mixed, and finally the mixture is mixed with a sodium alginate aqueous solution with the mass concentration of 1-4%; the mass volume ratio of the sodium alginate, the mass volume ratio of the gelatin and the mass volume ratio of the GelMA in the mixed solution after the mixing are respectively 1-2%, 0.5-1% and 5-15%. Finally, curing can be carried out by simultaneous printing with calcium salts or by light irradiation.

The bacteriostatic and anti-infective material can be nano silver, zinc, chitosan, honey, chitin and a blend of the materials, and the addition amount can refer to the prior art. In the preparation of the material for preparing the skin chip, the bacteriostatic anti-infection material can be mixed with the gel material. For example, when a mixed gel of GelMA gum and alginate or a mixture of GelMA gum, alginate and gelatin is selected, a mixed solution of the bacteriostatic and anti-infective material and GelMA gum and alginate or a mixture of GelMA gum, alginate and gelatin may be mixed. If the antibacterial and anti-infection material is nano-silver, the addition amount of the nano-silver in the mixed solution is 1-50 mg/L. If the antibacterial and anti-infection material is chitosan, the antibacterial and anti-infection material is mixed in the solution.

The growth factor for promoting wound healing can be epidermal growth factor, fibroblast growth factor, platelet-derived growth factor, human vascular endothelial growth factor, transfer growth factor, bone morphogenetic protein and the like, and the addition amount can refer to the prior art.

The skin chip structure with the micro-pipeline inside can be manufactured by rapid manufacturing processes such as 3D printing additive manufacturing, sacrificial layer manufacturing pouring and the like. The micro-pipeline in the chip is used for introducing liquid into the dressing after the dressing covers the wound. The introduced liquid can be debridement liquid, and the seepage absorbed by the chip from the wound is taken away, so that the seepage absorption capacity of the chip is improved. Or cell nutrient solution, and the nutrition is delivered to the new cells at the wound by a penetration mode, so that the recovery and healing of the wound are accelerated.

The skin chip of the invention can provide survival conditions for promoting the growth of transplanted cells at the wound. The transplanted cells may be cultured cells in vitro by spraying or smearing, or cells obtained by mincing and separating skin tissue. The skin chip can be free of cells, so that the storage time of the chip is prolonged, and the transportation condition is reduced. Particularly, the skin chip can be directly mixed with transplanted cells during manufacturing, namely the skin chip is ready to use, has customized characteristics, and omits the steps of cell spraying and the like on the wound.

Preferably, the outlet and the inlet of the micro-pipeline are connected with quick connectors with retention functions. Preferably, the skin chip perfusion interface of the invention adopts an indwelling quick connector for medical transfusion. After the chip covers the wound, the filling opening is communicated with an external liquid pumping device to circulate and replace liquid in the chip. After the pump liquid reaches the measurement, the connection can be disconnected, the remaining interface is left, and the connection is carried out again when the liquid is changed next time, so that the daily action of a patient is not influenced in the period. For the special requirements, a wearable micro-pump liquid device can be added to achieve the function of changing liquid in real time. Along with the cell growth in the skin chip and the fusion of the skin of a patient, the chip matrix can be slowly degraded along with the cell growth without an additional stripping step.

According to the invention, the skin chip matrix is composed of gel materials and contains antibacterial and anti-infection materials and growth factors for promoting wound healing. The chip is internally provided with a micro pipeline for liquid to flow through, two ends of the micro pipeline are provided with a pluggable fluid filling opening and an outlet, the chip has the effects of covering a wound, inhibiting bacteria, promoting wound healing and the like, and the chip is simple in processing process and environment-friendly.

When the skin chip for wound repair of the present invention is used for skin repair, the following method may be adopted:

the skin chip containing no skin graft cell comprises the steps (1) to (3)

The skin chip containing skin graft cells comprises the steps (2) to (3)

(1) Placing the skin graft cells at the wound site;

(2) covering the skin chip on the wound;

(3) the micro-channel in the skin chip is used for carrying out nutrient delivery and drug slow release on skin transplantation cells or carrying away absorbed seepage in the skin chip.

Compared with the prior art, the invention has the following advantages:

(1) the shape of the skin chip can be customized according to the shape of the wound, and 3D printing molding is adopted, so that the skin chip is ensured to be more attached to the shape of the wound, and the treatment effect is further improved.

(2) The skin chip internally comprises a micro-pipeline structure, and the absorbed seepage in the skin chip can be taken away by a mode of introducing liquid into the micro-pipeline, so that the seepage absorption capacity of the skin chip is improved, and on the other hand, the cell nutrient solution can be transmitted to transplanted cells at a wound in a permeating mode, so that a good growth environment is provided for the transplanted cells for a long time, the growth of the transplanted cells is facilitated, and the wound healing is accelerated.

(3) The invention uses the gel material with better biocompatibility, is beneficial to spreading of transplanted cells, and can mix the histiocyte at the wound in the manufacturing process of the skin chip, namely the preparation and use are carried out, thus omitting the spraying step of the transplanted cells.

(4) The skin chip is used for conveying nutrition and discharging waste through a micro-pipeline in the skin chip, so that the growth of cells is promoted, the original wound is covered, and the recovery of the wound is facilitated.

(5) The indwelling interface of the skin chip can be used as a quick connector for external pump liquid, allows continuous or timed liquid change, is convenient to use, and does not influence the daily action of a patient. The skin chip can be slowly degraded along with the growth of cells, and an additional stripping step is not needed.

Drawings

FIG. 1 is a schematic view of a wound healing skin patch capable of supplying nutrients according to the present invention.

Detailed Description

Example 1, the present invention provides a customizable dermal chip for wound repair and a method of making, comprising the steps of:

(1) establishing a skin chip appearance model and a path: and establishing a three-dimensional model of the skin chip according to the actual shape of the wound of the patient through three-dimensional modeling software. And generating a continuous 3D printing path of the skin chip by computer slicing software.

(2) Preparing a printing material: weighing a certain amount of biochemical sodium alginate powder, placing under an ultraviolet lamp for irradiation sterilization for half an hour, mixing the sodium alginate powder with deionized water according to the mass ratio of 1-4%, stirring for 24 hours by a magnetic stirrer, setting the temperature at 60 ℃, and setting the rotating speed at 120 rpm. And after uniform mixing, obtaining the sodium alginate aqueous solution with the mass concentration of 1-4%. GelMA (gelatin-methyl methacrylate) and prepared sodium alginate aqueous solution are mixed according to a certain mass ratio, the mass volume ratio of sodium alginate in the mixed solution after mixing is 1-2%, the mass volume ratio of GelMA is 5-15%, 1-50mg/L nano silver and growth factors aiming at cells at wound parts are added, and the mixture is uniformly mixed to prepare the substrate material suitable for cell growth and adhesion.

(3) Preparing a calcium chloride cross-linked material: weighing a certain amount of biochemical calcium chloride powder, placing under an ultraviolet lamp for irradiation and sterilization for half an hour, mixing the calcium chloride powder and deionized water according to the mass ratio of 2-4%, stirring for 1 hour by a magnetic stirrer, setting the temperature at 25 ℃ and the rotating speed at 120 rpm. And after being uniformly mixed, obtaining the calcium chloride aqueous solution with the mass concentration of 2-4%.

(4)3D printing of skin chips: and (3) using a coaxial extrusion head as an extrusion head of the printer, connecting the inner extrusion head with the calcium chloride solution prepared in the step (3), and connecting the outer extrusion head with the mixed material prepared in the step (2). During printing, the liquid passing speed ratio of the calcium chloride to the mixed material is 1: 1. Because the inner channel is communicated with the calcium chloride solution, the inner channel and the sodium alginate matrix of the outer channel can generate cross-linking reaction, and the inner channel is formed in the printed strip-shaped object. Meanwhile, the calcium chloride solution is used as an internal support material to prevent the collapse of the internal channel. And (3) printing the materials on a collecting plate by using a 3D printer according to the continuous path generated in the step (1) to form a skin chip with a customized shape, continuously printing for a certain distance after forming, reserving a liquid filling port on one side, and connecting a reserving interface to the filling port. In the printing process, 365nm ultraviolet light is used for irradiation, GelMA is stimulated by the ultraviolet light for curing, and the forming of a chip structure is facilitated.

The skin chip contains no cell, can be preserved for a long time and maintain bioactivity, and is beneficial to the processes of chip transportation, storage and the like. Additional cultured transplanted cells were sprayed onto the wound site prior to use of the skin chip. Then the skin chip is covered on the wound and the spraying cells are covered, the customized alginate matrix can be attached to the wound, cover the wound surface, absorb seepage and provide a wet healing environment. The silver ions can be used for growing bacteria at the wound all the time, and the growth factors are also in a slow release form, so that the growth of corresponding cells at the wound is promoted, and the wound healing is accelerated. Cell nutrient solution is introduced from the reserved perfusion opening, on one hand, absorbed seepage in the skin chip can be taken away, the seepage absorption capacity of the chip is improved, on the other hand, the cell nutrient solution can be conveyed to transplanted cells sprayed at the wound in a permeating mode, the growth of the transplanted cells is facilitated, and the wound healing is accelerated. The supply and the change of nutrient solution can adopt continuous or intermittent timing liquid change, realize the quick connection of pump liquid device and skin chip through keeping somewhere the interface, can disconnect after the liquid change is accomplished, do not influence patient's daily behavior.

Embodiment 2, the present invention provides a customizable skin chip containing transplanted cells and a preparation method thereof, comprising the following steps:

(1) establishing a skin chip model: and establishing a three-dimensional model of the skin chip and the internal nutrient channel according to the actual shape of the wound of the patient through three-dimensional modeling software. And a chip die corresponding to the shape of the wound is obtained by a rapid manufacturing means.

(2) Preparing a nutrient channel sacrificial layer scaffold: the scaffolds for the internal channels of the dermal chip were prepared according to the first step model using water-soluble materials.

(3) Weighing a certain amount of biochemical sodium alginate powder, placing the biochemical sodium alginate powder under an ultraviolet lamp for irradiation sterilization for half an hour, mixing the sodium alginate powder with deionized water according to the mass ratio of 1-4%, stirring the mixture by a magnetic stirrer for 24 hours, setting the temperature at 60 ℃, setting the rotating speed at 120rpm, uniformly mixing the mixture to obtain a sodium alginate aqueous solution with the mass concentration of 1-4%, preparing a 1-2% gelatin aqueous solution by the same method, mixing GelMA (gelatin-methyl methacrylate) with the prepared sodium alginate aqueous solution and the prepared gelatin aqueous solution according to the mass ratio, doping chitosan (the mass percentage is 1-2%) as an antibacterial material, adding a proper amount of cell growth factor (the mass percentage is 1-2%) into the mixed solution after the mixing is finished, mixing the cell growth factor with the transplanted cells cultured in advance, and ensuring the concentration of the cells to grow properly (1-1 × 10) (the mass percentage is 1-2%)⁵Per ml-1 × 10⁶Pieces/ml).

(4) Skin chip molding: pouring the prepared sodium alginate-gelatin-GelMA solution into a mold containing a sacrificial layer bracket, and irradiating by using 365nm ultraviolet light to start curing the GelMA component in the solution under the stimulation of the ultraviolet light. After the skin chip is completely cured and molded, the chip is soaked in deionized water to dissolve the material of the internal pipeline sacrificial layer, and an indwelling interface is connected to the inlet end and the outlet end of the channel to complete the preparation of the dressing.

The skin chip contains transplanted cells, so that a patient does not need to go through an additional cell spraying process, and medical instruments and steps needed by the patient are simplified. After the skin chip containing the transplanted cells is covered on the wound, the customized skin chip substrate can be attached to the wound, cover the wound surface, absorb seepage and provide a wet healing environment. The cells contained in the skin chip can be well adhered and grown in the sodium alginate-gelatin-GelMA matrix. In addition, cell nutrient solution is introduced from the reserved perfusion opening, on one hand, absorbed seepage in the skin chip and waste discharged by cells can be taken away, the seepage absorption capacity of the chip is improved, on the other hand, the cell nutrient solution can be transferred to transplanted cells in the chip in a permeating mode, and the cell growth is facilitated. The supply and the replacement of the nutrient solution can adopt continuous or intermittent timing liquid replacement, and are connected with the wearable micropump through the indwelling interface, so that the daily behavior of the patient is not influenced. After the cells are fused with the new skin of the wound, the skin chip matrix is degraded, the wound is repaired, and an additional chip stripping step is not needed.

Claims

1. A dermal chip for wound repair comprising a matrix of gel material having a microchannel in fluid communication therein, the microchannel having an outlet and an inlet located on the matrix; the substrate has a profile structure conforming to the wound surface; the matrix contains skin graft cells; the gel material is a mixture of GelMA glue and alginate or a mixture of GelMA glue, alginate and gelatin; when the mixed gel of GelMA glue and alginate is selected, the mass volume ratio of the sodium alginate in the mixed solution is 1-2%, and the mass volume ratio of GelMA is 5-15%; when the gel material is a mixture of GelMA gum, alginate and gelatin, the mass volume ratio of the sodium alginate in the mixed solution is 1-2%, the mass volume ratio of the gelatin is 0.5-1%, and the mass volume ratio of GelMA is 5-15%.

2. The skin chip for wound repair according to claim 1, wherein the matrix contains one or two of bacteriostatic anti-infective material and growth factor for promoting wound healing.

3. The skin chip for wound repair according to claim 2, wherein the bacteriostatic anti-infective material is selected from at least one of the following: nano silver, zinc, chitosan, honey and chitin.

4. The dermal chip for wound repair according to claim 2, wherein the growth factor for promoting wound healing is selected from one or more of the following: epidermal growth factor, fibroblast growth factor, platelet derived growth factor, human vascular endothelial growth factor, metastatic growth factor, bone morphogenetic protein.

5. The dermal chip for wound repair of claim 1, wherein the outlet and the inlet are connected with indwelling connectors.

6. A method for manufacturing a skin chip useful for wound repair according to any one of claims 1 to 5, comprising the steps of:

(2) preparing a material for manufacturing the skin chip;

wherein the step (1) and the step (2) are not limited in sequence.

7. The method of making a skin chip useful for wound repair according to claim 6, wherein said rapid manufacturing method is selected from the group consisting of 3D printing method, sacrificial layer manufacturing casting method.