A double-layer bone scaffold for treating femoral head necrosis and a construction method thereof

Abstract

This invention discloses a bilayer bone scaffold for treating femoral head necrosis and its construction method, relating to the field of bone tissue repair and reconstruction technology. The bilayer bone scaffold of this invention is constructed as a bilayer composite structure of cortical bone and cancellous bone, wherein the cortical bone and cancellous bone are constructed as porous structures. This invention includes the following steps: S1: Analyzing the internal structure of the femoral head using imaging technology; S2: Simulating the bilayer composite structure of cortical bone and cancellous bone by combining a three-period minimal surface; S3: Mixing three TPMS structures—P, G, and D—in pairs to obtain six different bilayer hybrid TPMS bone scaffolds. This invention, through the design of a bilayer hybrid structure, better mimics the hierarchical structure of natural bone, improving bone biomimicry. This invention, through optimized porous structure and permeability, provides a better growth environment for cell growth and tissue reconstruction, and its heterogeneity matches the performance of the bone tissue at the implantation site.

Description

Technical Field

[0001] This invention relates to the field of bone tissue repair and reconstruction technology, specifically to a double-layer bone scaffold for treating femoral head necrosis and its construction method. Background Technology

[0002] Avascular necrosis of the femoral head (ONFH) is a common and difficult-to-treat orthopedic disease, most prevalent in young adults aged 20-40. It progresses rapidly, often causing hip pain and functional impairment. Some studies have found that ONFH collapse is a direct result of decreased mechanical properties of the necrotic femoral head; without timely early treatment, 70%-80% of patients will progress to femoral head collapse within 3 years. While it has attracted extensive research interest over the past few decades, there is still no widely accepted consensus on its exact etiology and pathogenesis. Due to the complexity of its pathogenesis, an ideal cure has not yet been found, and there are no unified principles or consensus on the treatment of early-stage ONFH.

[0003] Current treatment options typically fall into two categories: surgical and non-surgical. Non-surgical treatment often employs conservative methods, including various medications and physiochemical therapies. Medications can alleviate pain, improve function, and slow disease progression, while physiochemical therapies can improve blood circulation and prevent femoral head collapse. However, none of these have been proven effective with high-level evidence, and most have adverse effects. The efficacy of non-surgical treatments is unstable and cannot prevent further collapse. Surgical treatments for ONFH are numerous, including total hip replacement, core decompression, bone grafting and support, and vascularized bone grafting. Some complex surgeries may not produce the desired results, and surgical treatments are highly invasive, have long recovery times, and are prone to complications. To slow the progression of ONFH in young adult patients, exploring active and effective hip joint protection methods in the early stages of ONFH, and delaying or even reversing disease progression, has significant clinical and social value. Therefore, seeking a highly effective and safe treatment method has become a current research hotspot in the field of osteonecrosis treatment.

[0004] In bone tissue engineering, scaffolds require structures with good internal morphology, making scaffold design particularly important. Currently, the unit cell is the basic structure of the scaffold. It can be divided into two types of design: nonparametric and parametric. Nonparametric design uses simple structures as the most basic pore-forming unit, constructing bone scaffold models based on cubic lattices with straight edges and sharp corners, or Boolean intersections derived from geometric prototypes such as spheres and cylinders. The edges are too sharp to integrate tightly with the native bone. Parametric design of bone scaffolds, on the other hand, utilizes the Triple Periodic Minimal Surface (TPMS) as the most commonly used. TPMS structures possess continuity and periodicity, are three-dimensionally non-self-intersecting, and have an average curvature of zero. Compared to the straight edges or sharp turns of simple geometric prototypes, TPMS have a unique helical structure, creating topological smoothness internally without sharp edges or corners. This facilitates stress transfer, thereby improving mechanical properties and making the stress distribution more uniform under load, effectively reducing stress concentration.

[0005] Natural bone tissue is a bilayered hybrid structure, consisting of a dense outer cortical bone and a sparse inner cancellous bone. The inherent structural characteristics of natural bone provide a template for constructing artificial bone scaffolds. Bilayered bone scaffolds, designed based on biomimetic structures inspired by natural structures, exhibit better performance than homogeneous bone scaffolds. Currently, homogeneous bone scaffolds cannot accurately mimic the structure of the human skeleton to perform different functions; after implantation, under load conditions, they may exhibit excessive mechanical properties, failing to meet the performance requirements of the bone.

[0006] Therefore, we propose a double-layer bone scaffold for treating femoral head necrosis and its construction method to address the problems mentioned above.

[0007] The information disclosed above in this background section is only for enhancing the understanding of the background section of this invention, and therefore may include prior art that is not known to those skilled in the art. Summary of the Invention

[0008] The purpose of this invention is to provide a double-layer bone scaffold for treating avascular necrosis of the femoral head and a method for constructing the scaffold, so as to solve the problems mentioned in the background art.

[0009] To achieve the above objectives, the present invention provides the following technical solution: a double-layer bone scaffold for treating avascular necrosis of the femoral head, wherein the double-layer bone scaffold is constructed as a double-layer composite structure of cortical bone and cancellous bone, and the cortical bone and cancellous bone are constructed as a porous structure.

[0010] This invention also provides a method for constructing a double-layer bone scaffold for treating avascular necrosis of the femoral head, comprising the following steps:

[0011] S1: Analyze the internal structure of the femoral head using imaging techniques;

[0012] S2: Combining three-period minimal surfaces to simulate the double-layer composite structure of cortical bone and cancellous bone;

[0013] S3: The three TPMS structures—P, G, and D—are mixed in pairs to obtain six different bilayer hybrid TPMS bone scaffolds.

[0014] Compared with the prior art, the beneficial effects of the present invention are:

[0015] (1) The present invention improves bone biomimicry by better mimicking the hierarchical structure of natural bone through the design of a double-layer hybrid structure.

[0016] (2) The present invention provides a better growth environment for cell growth and tissue reconstruction through optimized porous structure and permeability. Through its heterogeneity, it matches the bone tissue at the implantation site in performance. The cortical bone layer of the scaffold provides high strength to withstand the load, while the cancellous bone layer promotes cell nutrient exchange through its porous structure, supports cell survival and bone tissue development, and meets metabolic and energy needs.

[0017] (3) This invention utilizes CT image analysis to achieve precise control of porosity. By adjusting the parameters of the double-layer structure, the internal lattice structure configuration can be adjusted to change the mechanical and biological properties of the bone scaffold.

[0018] The above overview is for illustrative purposes only and is not intended to be limiting in any way. In addition to the illustrative aspects, embodiments, and features described above, further aspects, embodiments, and features of the invention will become readily apparent from the accompanying drawings and the following detailed description. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the GP double-layer bone scaffold structure of the present invention;

[0020] Figure 2 This is a schematic diagram of the PG double-layer bone scaffold structure of the present invention;

[0021] Figure 3 This is a schematic diagram of the GD double-layer bone scaffold structure of the present invention;

[0022] Figure 4 This is a schematic diagram of the DG double-layer bone scaffold structure of the present invention;

[0023] Figure 5 This is a schematic diagram of the PD double-layer bone scaffold structure of the present invention;

[0024] Figure 6 This is a schematic diagram of the DP double-layer bone scaffold structure of the present invention. Detailed Implementation

[0025] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0026] A double-layer bone scaffold for treating avascular necrosis of the femoral head, the double-layer bone scaffold being constructed as a double-layer composite structure of cortical bone and cancellous bone, the cortical bone and cancellous bone being constructed as a porous structure.

[0027] A method for constructing a double-layered bone scaffold for treating avascular necrosis of the femoral head includes the following steps:

[0028] S1: Analyze the internal structure of the femoral head using imaging techniques; specifically, achieve precise control of porosity through CT image analysis.

[0029] S2: Combining three-period minimal surfaces, it simulates the bilayer composite structure of cortical and cancellous bone; specifically, by adjusting the parameters of the bilayer structure, the internal lattice structure configuration is adjusted, thereby changing the mechanical and biological properties of the bone scaffold.

[0030] S3: The three TPMS structures—P, G, and D—are mixed in pairs to obtain six different bilayer hybrid TPMS bone scaffolds.

[0031] The present invention constructs six different bilayer hybrid TPMS bone scaffolds, such as Figure 1 As shown, this structure effectively provides mechanical support to the femoral head and helps restore blood supply, preventing further collapse. This unique bone scaffold structure provides stable support and appropriate pressure distribution during treatment, promoting repair and regeneration of necrotic areas. It is suitable for treating femoral head collapse and for repairing and reconstructing bone tissue in other areas.

[0032] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0033] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A double-layer bone scaffold for treating avascular necrosis of the femoral head, characterized in that, The double-layer bone scaffold is constructed as a double-layer composite structure of cortical bone and cancellous bone, and the cortical bone and cancellous bone are constructed as a porous structure.

2. The method for constructing a double-layer bone scaffold for treating femoral head necrosis as described in claim 1, characterized in that, Includes the following steps: S1: Analyze the internal structure of the femoral head using imaging techniques; S2: Combining three-period minimal surfaces to simulate the double-layer composite structure of cortical bone and cancellous bone; S3: The three TPMS structures—P, G, and D—are mixed in pairs to obtain six different bilayer hybrid TPMS bone scaffolds.

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