Degradable breast prosthesis shaping mesh having heterogeneous hierarchical porous structure and preparation method therefor

Abstract

Disclosed is a degradable breast prosthesis shaping mesh (10) having a heterogeneous hierarchical porous structure, comprising a macroporous structure layer (100) and a microporous structure layer (200). The macroporous structure layer (100) and the microporous structure layer (200) are formed by alternately arranging and combining degradable fibers to conform to a breast prosthesis, thereby providing the mechanical properties and tissue adhesion properties required by the mesh (10). The macroporous structure layer and the microporous structure layer cooperate to achieve the function of integrating the prosthesis with the tissue, without the need for an additional suturing fixation device. The overall shape of the mesh (10) is designed as a hemispherical upper cover (11) and a lower end cover rim (12), thereby simplifying the assembly process with the prosthesis and improving the surgical efficiency. The mesh (10) possesses excellent mechanical properties and shaping ability. Moreover, a microporous structure facilitates the adhesion and migration of cells, reduces the rejection reaction of the body, and significantly reduces the incidence of capsular contracture.

Description

Biodegradable breast implant shaping net with heterogeneous hierarchical porous structure and its preparation method

[0001] Cross-references to related applications

[0002] This application claims priority to Chinese patent application 202411690122.8, filed on February 25, 2025, entitled “A biodegradable breast implant shaping net with a heterogeneous hierarchical porous structure,” the entire contents of which are incorporated herein by reference. Technical Field

[0003] This invention relates to the field of plastic surgery and breast tissue engineering technology, specifically to a biodegradable breast implant shaping net with a heterogeneous hierarchical porous structure and its preparation method. Background Technology

[0004] Breast cancer ranks first among malignant tumors in women. Surgical removal of breast tumors remains the most effective treatment strategy, and postoperative breast reconstruction improves patients' quality of life and physical appearance. Currently, implant reconstruction has become the main method of breast reconstruction after breast tumor removal surgery. However, traditional silicone implants lack effective fixation with autologous tissue, leading to complications such as implant displacement and capsular contracture. In severe cases, a second surgery may be required to remove the implant, causing significant harm to the patient's physical and mental health.

[0005] To address this issue, the clinical practice widely employs the method of adding breast implant overlay sheets to the surface of silicone implants to enhance their integration with autologous tissue. Breast implant overlay sheets include titanium-coated polypropylene sheets and natural biomaterials, but existing breast implant overlay sheets are all flat in design and require folding before they can be used to cover the implant, which easily creates numerous wrinkles, affecting fit and integration. Summary of the Invention

[0006] To overcome the shortcomings of existing technologies, an innovative biodegradable breast implant shaping net with a heterogeneous hierarchical porous structure and its preparation method are proposed. Using medical-grade biodegradable polymers as the material, the net is custom-designed according to the curved shape of the implant, achieving a surface fit consistent with silicone implants. Its ingenious structural design provides necessary mechanical support through coarse fiber and large-pore structural layers, effectively preventing wrinkles and displacement. Furthermore, the heterogeneous mesh of the large-pore structural layer strengthens the net's mechanical properties in areas of high stress, effectively alleviating the compression of the implant due to breast sagging, providing support and lift. Simultaneously, the larger fiber diameter and pore size provide stable anchor points for implant placement, ultimately achieving both implant fixation and breast shaping functions. The fine fiber and microporous structural layers, through their refined surface microstructure, promote tissue adhesion and growth, enhancing tissue-implant integration while facilitating tissue ingrowth and preventing capsular contracture.

[0007] To achieve the above objectives, the technical solution of the present invention is as follows: a biodegradable breast implant shaping net with a heterogeneous hierarchical porous structure, which is composed of at least one layer of coarse fibers and a large-pore structure and at least one layer of fine fibers and a micropore structure. That is, at least one layer of coarse fibers forms a large-pore structure and at least one layer of fine fibers forms a micropore structure. The two are arranged alternately and tightly combined and perfectly conform to the breast implant, respectively providing mechanical properties for fixing the breast implant and biological properties for promoting tissue adhesion and avoiding capsular contracture.

[0008] The pore size of the large-pore structure is larger than that of the micro-pore structure.

[0009] The biodegradable breast implant shaping net with a heterogeneous hierarchical porous structure features a large-pore structure layer with a heterogeneous mesh. The net includes a first region and a second region. The large-pore structure layer is structurally densified in the first region to prevent implant displacement and improve the mechanical support of the net. The second region, which bears the weight of the implant, is designed with an elastic structure to simulate the ligament structure in a natural human breast, resulting in a natural shaping effect on the breast.

[0010] The biodegradable breast implant shaping net with a heterogeneous hierarchical porous structure consists of two parts: a hemispherical top cover and a lower end cover. The shape of the hemispherical top cover is consistent with the curved surface of the implant. The lower end cover is arranged in a circumferential array along the bottom circumference of the hemispherical top cover, with no fewer than two arrays. The radial length of the lower end cover is 2-3 cm larger than the radius of the bottom circumference of the hemispherical top cover, which facilitates perfect wrapping of the implant after folding.

[0011] The lower end caps of the biodegradable breast implant shaping net with a heterogeneous hierarchical porous structure are connected to each other after folding, and the connection method includes at least one of the following: buckle, medical suture, medical adhesive, mechanical pressing, or reagent bonding.

[0012] The biodegradable breast implant shaping net with a heterogeneous hierarchical porous structure has a macropore structure layer with a thickness of 0.5–2 mm and a fiber width of 0.2–0.8 mm; the biodegradable breast implant shaping net with a hierarchical porous structure has a micropore structure layer with a thickness of 0.01–0.2 mm and a fiber width of 0.001–0.15 mm.

[0013] The biodegradable breast implant shaping net with a heterogeneous hierarchical porous structure is manufactured using 3D printing technology, mold making, or layer-by-layer assembly.

[0014] The biodegradable breast implant shaping net with a heterogeneous hierarchical porous structure has holes in the shape of polygons, closed curves, or one or more of these shapes.

[0015] The biodegradable breast implant shaping net with a heterogeneous hierarchical porous structure is made of medical biodegradable polymer materials, which include one or more of polyhydroxyalkanoates (PHA), polycaprolactone (PCL), polyglycolic acid (PGA), polybutylene succinate (PBS) and their copolymers, polyvinyl alcohol (PVA), polylactic acid (PLA), and polylactic acid-glycolic acid copolymer (PLGA).

[0016] This invention also provides a method for preparing a biodegradable breast implant shaping net with a heterogeneous hierarchical porous structure, comprising: obtaining a net model consistent with the curved shape of the breast implant according to the predetermined size of the breast implant, the net model including a macropore structure layer model and a micropore structure layer model; obtaining a macropore structure layer and a micropore structure layer according to the net model; assembling the macropore structure layer and the micropore structure layer to obtain the net, wherein the net is composed of at least one layer of coarse fibers and at least one layer of fine fibers, and the formed pore structure includes a macropore structure and a micropore structure, which are interleaved and tightly combined and conform to the shape of the breast implant.

[0017] The step of obtaining the large-pore structure layer and the micro-pore structure layer based on the net model includes: obtaining the large-pore structure layer and the micro-pore structure layer using 3D printing technology based on the net model.

[0018] The step of obtaining the large-pore structure layer and the micro-pore structure layer according to the net model includes: using a mold-making method to produce the large-pore structure layer according to the net model; and using freeze-drying technology to produce the micro-pore structure layer.

[0019] This invention provides a biodegradable breast implant shaping net with a heterogeneous hierarchical porous structure and its preparation method, which has the following advantages compared with the prior art:

[0020] 1. Adaptability to the curved shape of silicone implants. The biodegradable breast implant shaping net of this invention has a heterogeneous hierarchical porous structure that is consistent with the curved shape of silicone implants, which significantly improves the adaptability of the covering sheet and effectively solves the problems of poor fit and wrinkles of traditional planar covering sheets, while avoiding implant slippage caused by shape mismatch;

[0021] 2. Simplified surgical placement process. This invention features a biodegradable breast implant shaping mesh with a hemispherical top cover and a foldable flat edge, designed with a heterogeneous, graded, porous structure, making the implant placement process simple and quick. The porous structure provides multiple anchor points for the implant to the tissue, eliminating the need for additional suture fixation devices and simplifying the surgical procedure.

[0022] 3. Superior mechanical / biological properties resulting from the heterogeneous hierarchical porous structure. The large-pore structure layer of the biodegradable breast implant shaping net of this invention, with its heterogeneous hierarchical porous structure, possesses excellent mechanical properties and surface roughness, effectively supporting and fixing the implant to prevent displacement, thereby shaping the breast. The fine pores and fiber size of the microporous structure layer are conducive to cell adhesion and tissue growth, inducing regeneration, reducing rejection reactions, and lowering the incidence of capsular contracture.

[0023] 4. Biocompatibility and Degradation Characteristics. The biodegradable breast implant shaping net of this invention, with its heterogeneous hierarchical porous structure, exhibits excellent biocompatibility and degradation performance. As new tissue grows, the net gradually degrades. Simultaneously, due to its large wire diameter, the degradation time of the large-pore structure layer is slightly longer, providing continuous restraint for tissue growing along the micropore structure layer and effectively preventing capsule formation. Attached Figure Description

[0024] Figure 1 is a schematic diagram of the biodegradable breast implant shaping net with a heterogeneous hierarchical porous structure according to the present invention.

[0025] Figure 2 is a schematic diagram of the manufacturing process of the biodegradable breast implant shaping net with a heterogeneous hierarchical porous structure in Example 1.

[0026] Figure 3 is a physical image of the biodegradable breast implant shaping net with a heterogeneous hierarchical porous structure in Example 1.

[0027] Figure 4 is a schematic diagram of the implant coverage effect of a biodegradable breast implant shaping net with a heterogeneous hierarchical porous structure.

[0028] Figure 5 is a photograph of the biodegradable breast implant shaping net with a heterogeneous hierarchical porous structure in Example 2.

[0029] Figure 6 shows the cell culture results of different regions of the biodegradable breast implant shaping net with a heterogeneous hierarchical porous structure in Example 2. Detailed Implementation

[0030] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0031] Breast cancer ranks first among malignant tumors in women. Surgical removal of breast tumors remains the most effective treatment strategy, but the permanent loss of breast tissue after tumor removal seriously affects the patient's physical and mental health. As patients who have undergone breast tumor removal increasingly demand higher quality of life and better aesthetic results, more and more patients are choosing breast reconstruction. Currently, implant reconstruction has become the main method of breast reconstruction after breast tumor removal due to its advantages such as simple surgery and rapid recovery. However, traditional silicone implants lack effective fixation with autologous tissue, leading to complications such as implant displacement and capsular contracture. In severe cases, a second surgery may be required to remove the implant, causing significant harm to the patient's physical and mental health.

[0032] To address this issue, clinical practice widely employs the method of adding breast implant overlay sheets to the surface of silicone implants to enhance their integration with autologous tissue. Currently available breast implant overlay sheets are primarily titanium-coated polypropylene sheets, which offer excellent mechanical properties and provide good fixation and support for the silicone implant. However, their high rigidity leads to noticeable foreign body sensation reported by patients. Furthermore, these sheets are non-degradable, posing potential long-term risks within the patient's body. As alternative materials, natural biomaterials such as bovine pericardium and decellularized dermal matrix are also frequently used to overlay silicone implants. While these natural biomaterials possess good biocompatibility and biodegradability, and their mechanical properties are similar to autologous tissue, they carry the potential risk of animal-derived viral transmission and exhibit poor product consistency. More importantly, existing breast implant overlay sheets are all flat in design, requiring folding before application, which easily creates numerous wrinkles, affecting fit and integration.

[0033] Based on this, the present invention provides a biodegradable breast implant shaping net with a heterogeneous hierarchical porous structure, as shown in Figures 1 and 3. Figure 1 is a schematic diagram of the structure of the biodegradable breast implant shaping net with a heterogeneous hierarchical porous structure of the present invention, and Figure 3 is a physical image of the biodegradable breast implant shaping net with a heterogeneous hierarchical porous structure in Example 1. A biodegradable breast implant shaping net 10 with a heterogeneous hierarchical porous structure is composed of at least one layer of coarse fibers and at least one layer of fine fibers. The at least one layer of coarse fibers forms a large-pore structure layer 100, and the at least one layer of fine fibers forms a micropore structure layer 200. The two layers are arranged alternately and tightly combined, perfectly conforming to the shape of the breast implant, respectively providing mechanical properties for fixing the breast implant and biological properties for promoting tissue adhesion and avoiding capsular contracture.

[0034] The biodegradable breast implant shaping net 10 with a heterogeneous hierarchical porous structure has a large-pore structure layer 100 with a heterogeneous mesh. The biodegradable breast implant shaping net 10 includes a first region 110 and a second region 120. The first region 110 is the region that bears the weight of the implant. As shown in Figures 1 and 3, the large-pore structure layer 100 has a denser structure in the first region 110 of the net 10. By reducing the pore size of the large-pore structure layer 100 in the first region 110, the structure is denser, which improves the mechanical support of the net, prevents the implant from sagging and shifting, and produces a shaping effect on the breast.

[0035] Example 1:

[0036] Referring to Figure 2, which is a schematic diagram of the manufacturing process of the biodegradable breast implant shaping net with a heterogeneous hierarchical porous structure in Example 1, polycaprolactone (PCL), a medical biodegradable material, was chosen as the manufacturing material for the net due to its good biocompatibility and degradation characteristics.

[0037] Based on the predetermined silicone implant size, a net model with the same curved surface shape as the implant is designed using computer-aided design (CAD) software, as shown in Figure 2. The model includes three large-pore structure layers 100 and ten micro-pore structure layers 200, as shown in Figure 3.

[0038] As shown in Figure 2, PCL material is printed layer by layer using 3D printing technology to form a mesh bag 10 with a heterogeneous hierarchical porous structure. The printed mesh bag structure is shown in Figure 3. The large-pore structure layer 100 has a pore size of 1 mm in the first region 110 and a pore size of 4 mm in the second region 120. The fiber width of the large-pore structure layer 100 is 0.2 mm, and its thickness is 0.6 mm. The micropore structure layer 200 has a pore size of 0.1 mm, a fiber width of 0.001 mm, and a thickness of 0.01 mm. The pore structure of the large-pore structure layer 100 is rectangular, and the pore structure of the micropore structure layer 200 is rhomboid.

[0039] The biodegradable breast implant shaping net 10 with a heterogeneous hierarchical porous structure also includes a hemispherical upper cover 11 and a lower end cover 12. The shape of the hemispherical upper cover 11 is consistent with the curved surface of the implant. The lower end cover 12 is distributed in a circumferential array along the bottom circumference of the hemispherical upper cover 11. In this embodiment, there are three lower end cover 11s. The hemispherical upper cover 11 and the lower end cover 12 of the net 10 are assembled together, as shown in Figure 4. Figure 4 is a schematic diagram of the implant coverage effect of the biodegradable breast implant shaping net with a heterogeneous hierarchical porous structure, ensuring that both can completely cover the implant after folding. Medical sutures are used to connect the cover edges of the net after folding, ensuring a firm connection without gaps.

[0040] During the surgery, a net is wrapped around the silicone implant, utilizing its heterogeneous porous structure for mechanical support and the large pores that form anchor points with the tissue to achieve breast shaping.

[0041] Example 2:

[0042] Polylactic acid-glycolic acid copolymer (PLGA) was chosen as the material for manufacturing the net.

[0043] Based on the specific shape of the silicone prosthesis, a graded porous structure mesh with different pore sizes was designed to adapt to the mechanical and biological needs of different areas.

[0044] A mold-making method is used to fabricate a large-pore structural layer 100 from PLGA material into a mesh bag 10, and a micro-pore structural layer 200 is fabricated using freeze-drying technology. The fibers of the large-pore structural layer 100 and the micro-pore structural layer 200 are ensured to be interleaved to form a stable structure. The fabricated mesh bag undergoes quality inspection to ensure that the shape and size of the holes meet the design requirements.

[0045] In this embodiment, considering the shape and size of the implant, a hierarchical porous structure is designed for the mesh pouch. The large-pore structure layer 100 is fabricated using 3D printing. This layer consists of two layers with an average pore size of 1.5 mm, a fiber width of 0.8 mm, and a thickness of 1.6 mm. The micropore structure layer 200 is fabricated using an electrospun PLGA membrane freeze-dried. This layer also consists of two layers with an average pore size of 0.15 mm, a fiber width of 0.1 mm, and a thickness of 0.2 mm. A magnified image of the mesh pouch 10 is shown in Figure 5. Figure 5 is a photograph of the biodegradable breast implant shaping mesh pouch with a heterogeneous hierarchical porous structure from Example 2.

[0046] Bone marrow mesenchymal stem cells were further inoculated onto the mesh bag. After five days of culture, the cell viability and death staining results are shown in Figure 6. Figure 6 shows the cell culture results of different regions of the biodegradable breast implant shaping mesh bag with a heterogeneous hierarchical porous structure from Example 2. Green and blue represent live cells, and red represents dead cells. The figure shows a large number of live cells, but no red dead cells, indicating good cell growth. These results demonstrate that the mesh bag has good biocompatibility and cell growth promoting properties.

[0047] Assemble the various parts of the net bag and glue them together using medical adhesive to ensure that the bonding strength meets the requirements of the surgery.

[0048] During the surgery, the net is combined with the prosthesis, and its hierarchical porous structure promotes tissue growth and adhesion, while preventing prosthesis displacement and capsular contracture.

[0049] Furthermore, any content not described in detail in this specification is existing technology known to those skilled in the art.

[0050] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0051] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A biodegradable breast implant shaping net with a heterogeneous hierarchical porous structure, wherein, It consists of at least one layer of coarse fibers and at least one layer of fine fibers, and the resulting pore structure includes large-pore structure and micro-pore structure, which are interleaved and tightly combined and conform to the shape of the breast implant.

2. The biodegradable breast implant shaping net with a heterogeneous hierarchical porous structure according to claim 1, wherein, The pore size of the large-pore structure is larger than that of the micro-pore structure.

3. A biodegradable breast implant shaping net with a heterogeneous hierarchical porous structure according to claim 1 or 2, wherein, The coarse fiber, large-pore structure layer mesh is a heterogeneous mesh. The net includes a first region and a second region. The large-pore structure layer is structurally densified in the first region and has an elastic structure in the second region.

4. A biodegradable breast implant shaping net with a heterogeneous hierarchical porous structure according to any one of claims 1 to 3, wherein, The biodegradable breast implant shaping net with a heterogeneous hierarchical porous structure consists of two parts: a hemispherical top cover and a lower end cover. The shape of the hemispherical top cover is consistent with the surface of the implant. The lower end cover is arranged in a circumferential array along the bottom circumference of the hemispherical top cover, with no fewer than two arrays. The radial length of the lower end cover is 2-3 cm larger than the radius of the bottom circumference of the hemispherical top cover.

5. A biodegradable breast implant shaping net with a heterogeneous hierarchical porous structure according to claim 4, wherein, The lower end caps of the biodegradable breast implant shaping net with a heterogeneous hierarchical porous structure are connected to each other after folding, and the connection method includes at least one of the following: buckle, medical suture, medical adhesive, mechanical pressing, and reagent bonding.

6. A biodegradable breast implant shaping net with a heterogeneous hierarchical porous structure according to any one of claims 1 to 5, wherein, The thickness of the large-pore structure layer is 0.5–2 mm, and the fiber width is 0.2–0.8 mm; the thickness of the micropore structure layer is 0.01–0.2 mm, and the fiber width is 0.001–0.15 mm.

7. A biodegradable breast implant shaping net with a heterogeneous hierarchical porous structure according to any one of claims 1 to 6, wherein, The biodegradable breast implant shaping net with a heterogeneous hierarchical porous structure is assembled using 3D printing technology, mold making, freeze drying, and layer-by-layer stacking.

8. A biodegradable breast implant shaping net with a heterogeneous hierarchical porous structure according to any one of claims 1 to 7, wherein, The aperture structure shape is one or more of polygons and closed curved shapes.

9. A biodegradable breast implant shaping net with a heterogeneous hierarchical porous structure according to any one of claims 1 to 8, wherein, The biodegradable breast implant shaping net with a heterogeneous hierarchical porous structure is made of medical biodegradable polymer materials, including one or more of polyhydroxyalkanoates (PHA), polycaprolactone (PCL), polyglycolic acid (PGA), polybutylene succinate (PBS) and its copolymers, polyvinyl alcohol (PVA), polylactic acid (PLA), and polylactic acid-glycolic acid copolymer (PLGA).

10. A method for preparing a biodegradable breast implant shaping net with a heterogeneous hierarchical porous structure, wherein, include: Based on the predetermined size of the breast implant, a net model is obtained that conforms to the curved shape of the implant. The net model includes a large-pore structure layer model and a micro-pore structure layer model. Based on the net model, a large-pore structure layer and a micro-pore structure layer are obtained; Assemble the large-pore structure layer and the micro-pore structure layer to obtain the net bag, wherein the net bag is composed of at least one layer of coarse fiber and one layer of fine fiber, and the formed pore structure includes a large-pore structure and a micro-pore structure, which are arranged alternately and tightly combined and conform to the shape of the breast implant.

11. The method for preparing a biodegradable breast implant shaping net with a heterogeneous hierarchical porous structure according to claim 10, wherein, The step of obtaining the large-pore structure layer and the micro-pore structure layer based on the net model includes: obtaining the large-pore structure layer and the micro-pore structure layer using 3D printing technology based on the net model.

12. The method for preparing a biodegradable breast implant shaping net with a heterogeneous hierarchical porous structure according to claim 10, wherein, The process of obtaining the large-pore structure layer and the micro-pore structure layer based on the net model includes: fabricating the large-pore structure layer using a mold-making method based on the net model; and fabricating the micro-pore structure layer using freeze-drying technology.

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