A sutureless composite artificial cornea and its preparation method

Abstract

This invention discloses a sutureless composite artificial cornea, comprising a polymer posterior membrane and a biological anterior membrane fixed to the anterior surface of the polymer posterior membrane. The biological anterior membrane is divided into a central zone and a peripheral zone. The peripheral zone contains several radially arranged tunnels, with the head end of each tunnel located on the upper surface of the peripheral zone and the tail end located at the outer edge of the peripheral zone. Each tunnel contains a pre-embedded tissue fixation guidewire, and the length of the tissue fixation guidewire is greater than the length of the tunnel. The advantages of this invention are: by setting radial tunnels within the peripheral zone of the biological anterior membrane and pre-embedding tissue fixation guidewires within the tunnels, during surgery, the tissue fixation guidewires are pushed in along the tail end of the tunnels, allowing them to be inserted into the corneal implant bed, achieving fixation between the cornea and the corneal implant bed. This avoids corneal astigmatism caused by suturing and simplifies the surgical procedure.

Description

Technical Field

[0001] This invention relates to the field of artificial cornea technology, and in particular to a sutureless composite artificial cornea and its preparation method. Background Technology

[0002] Currently, all corneas used in clinical practice, whether donated, bio-based, or artificial, have their own drawbacks and fail to meet optimal clinical standards. Therefore, composite artificial corneas have emerged in recent years. For example, CN109157305A discloses a composite artificial cornea and its preparation method, comprising a central optical column made of poly(hydroxyethyl methacrylate) (PHEMA) and a corneal skirt structure made of decellularized matrix hydrogel. This design combines the advantages of existing bio-based and artificial corneas, partially addressing the current shortage of corneal materials.

[0003] However, donated corneas, bio-corneas, artificial corneas, or composite artificial corneas used clinically can only be corrected through surgical suturing, and all of them will produce astigmatism post-surgery, making it difficult to achieve the expected optimal post-operative visual acuity. The aforementioned post-operative astigmatism problem cannot be solved using existing techniques. The reason is that the curvature of all diameters of a normal cornea is consistent, resulting in a uniform refractive index. However, the traction force at each suture point varies, causing abnormal corneal refraction and resulting in corneal astigmatism. Furthermore, corneal astigmatism caused by surgical suturing is irregular astigmatism, therefore it cannot be corrected with glasses to improve post-operative visual acuity. Summary of the Invention

[0004] To address the aforementioned problems, this invention proposes a sutureless composite artificial cornea and its preparation method, thereby resolving the issue of corneal astigmatism caused by existing corneal transplantation procedures.

[0005] To address the aforementioned technical problems, the first aspect of this invention discloses a sutureless composite artificial cornea, comprising a polymer posterior membrane and a biological anterior membrane fixed to the anterior surface of the polymer posterior membrane. The biological anterior membrane is divided into a central region and a peripheral region. A plurality of radially arranged tunnels are embedded within the peripheral region. The head end of each tunnel is located on the upper surface of the peripheral region, and the tail end of each tunnel is located at the outer edge of the peripheral region. Each tunnel contains a pre-placed tissue fixation guidewire, and the length of the tissue fixation guidewire is greater than the length of the tunnel.

[0006] In some embodiments, the material of the pre-biofilm is collagen, hydrogel, silk protein, or cellulose.

[0007] In some embodiments, the polymeric back membrane is made of PMMA or PHEMA.

[0008] In some embodiments, the front surface of the polymer back membrane is uniformly distributed with integrally formed filamentous protrusions.

[0009] In some embodiments, the ends of the filamentous protrusions form a first enlargement.

[0010] In some embodiments, the tail of the tissue fixation guidewire is provided with barbs, and the head of the tissue fixation guidewire forms a second enlargement.

[0011] In some embodiments, the tissue fixation guidewire is made of titanium or a polymer material.

[0012] In some embodiments, the tissue fixation guidewire is made of a biodegradable and absorbable biomaterial.

[0013] In some embodiments, the front surface of the polymeric back membrane is hydrophilic, and the rear surface of the polymeric back membrane is hydrophobic.

[0014] The second aspect of this invention discloses a preparation method for preparing the above-mentioned sutureless composite artificial cornea, comprising the following steps:

[0015] The polymer backsheet with the desired curvature is fabricated using a micro-precision lathe, 3D printing, or casting.

[0016] Biomaterials are attached to the front surface of the polymer back membrane using mold casting, 3D printing, or spraying methods to form the biomaterial front membrane.

[0017] The tunnel cutter enters from the top of the peripheral area and exits through the outer edge of the peripheral area; several tunnels are radially distributed within the peripheral area.

[0018] The tissue fixation guidewire is inserted into the tunnel.

[0019] A third aspect of this invention discloses yet another preparation method for preparing the above-mentioned sutureless composite artificial cornea, comprising the following steps:

[0020] The biopre-membrane with the desired curvature is fabricated using micro-precision lathe machining, 3D printing, or casting.

[0021] The central portion of the posterior surface of the bio-prepared membrane is removed in a mushroom-shaped manner to obtain the bio-prepared membrane with a grooved structure;

[0022] The polymer material is attached to the posterior surface of the pre-biofilm using a mold casting, 3D printing, or spraying method to form the polymer posterior membrane.

[0023] The interface between the polymer posterior membrane and the peripheral region 22 of the biological anterior membrane is designed with tunnels. The tunnels enter from the top of the biological anterior membrane with a grooved structure and exit from the outer edge of the peripheral region. Several tunnels are radially distributed in the peripheral region.

[0024] The tissue fixation guidewire is inserted into the tunnel.

[0025] The beneficial effects of this invention are as follows: by setting radial tunnels inside the peripheral area of ​​the biological anterior membrane and pre-positioning tissue fixation guide wires in the tunnels, the tissue fixation guide wires can be pushed in along the tail end of the tunnels during the operation, thereby inserting the tissue fixation guide wires into the patient's corneal implant bed and achieving fixation between the cornea and the corneal implant bed. This avoids corneal astigmatism caused by suturing operations, reduces the difficulty of the operation, simplifies the operation, shortens the operation time, and improves the postoperative efficacy. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the sutureless composite artificial cornea disclosed in Embodiment 1 of the present invention;

[0027] Figure 2 for Figure 1 A magnified view of the area along line A;

[0028] Figure 3 for Figure 1 A magnified view of the area along line B;

[0029] Wherein: 1-Polymer posterior membrane, 2-Biological anterior membrane, 11-Filamentous protrusion, 21-Central region, 22-Peripheral region, 221-Tunnel, 222-Tissue fixation guidewire, 111-First enlargement, 2221-Barb, 2222-Second enlargement. Detailed Implementation

[0030] To make the objectives, technical solutions, and advantages of this invention clearer and more explicit, the content of this invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, only the parts relevant to this invention are shown in the accompanying drawings, not all of them.

[0031] Example 1

[0032] This embodiment proposes a sutureless composite artificial cornea. By setting radial tunnels 221 inside the peripheral area 22 of the biological anterior membrane 2, and pre-positioning tissue fixation guide wires 222 within the tunnels 221, the tissue fixation guide wires 222 are pushed in along the tail end of the tunnels 221 during the operation, thus inserting the tissue fixation guide wires 222 into the patient's corneal implant bed to achieve fixation between the cornea and the corneal implant bed. This avoids corneal astigmatism caused by suturing, reduces the difficulty of the operation, simplifies the operation, shortens the operation time, and improves the postoperative efficacy.

[0033] like Figure 1 As shown, this sutureless composite artificial cornea includes a polymer posterior membrane 1 and a biological anterior membrane 2 fixed to the anterior surface of the polymer posterior membrane 1. The biological anterior membrane 2 is divided into a central zone 21 and a peripheral zone 22. Several radially arranged tunnels 221 are embedded within the peripheral zone 22. The head end of each tunnel 221 is located on the upper surface of the peripheral zone 22, and the tail end is located at the outer edge of the peripheral zone 22. Each tunnel 221 contains a pre-embedded tissue fixation guidewire 222, and the length of the tissue fixation guidewire 222 is greater than the length of the tunnel 221. It should be noted that the tissue fixation guidewire 222 has a certain degree of elasticity, allowing for some deformation during advancement, and also possesses a certain degree of rigidity, allowing it to be pushed by tools until it penetrates the patient's corneal implant bed. Furthermore, since the central zone 21 is the pupillary light-entry point, the tunnels 221 should be located within the peripheral zone 22 and should not intrude into the central zone 21. The diameter of the central zone 21 can be within the range of 3–5 mm.

[0034] Optionally, the material of the pre-biofilm 2 may be collagen, hydrogel, silk protein, or cellulose.

[0035] Optionally, the material of the polymer back membrane 1 is PMMA or PHEMA.

[0036] The aforementioned polymer posterior membrane 1 is primarily used as the optical component and support component of the artificial cornea. To further enhance the bonding strength between the polymer posterior membrane 1 and the biological anterior membrane 2, thereby preventing the biological anterior membrane 2 from detaching, in one example, such as... Figure 2 As shown, the front surface of the polymer posterior membrane 1 is uniformly distributed with integrally formed filamentous protrusions 11. These filamentous protrusions 11 increase the contact area between the polymer posterior membrane 1 and the biological anterior membrane 2, thereby initially enhancing their bonding strength. In this embodiment, the initially liquid biomaterial is poured onto the upper surface of the polymer posterior membrane 1, and the shape of the biological anterior membrane 2 is shaped using a mold or similar means.

[0037] More preferably, the end of the filamentous protrusion 11 forms a first enlargement 111, the diameter of which is larger than the diameter of the filamentous protrusion 11, which can further prevent the biological anterior membrane 2 from detaching.

[0038] As another preferred embodiment of the present invention, please continue to refer to Figure 2 The tail of the tissue fixation guidewire 222 is provided with a barb 2221, such as Figure 3 As shown, the head of the tissue fixation guidewire 222 forms a second enlargement 2222. During the surgery, these tissue fixation guidewires 222 are inserted into the corneal implant bed along the tunnel 221 using tools to fix the cornea, while the second enlargement 2222 helps to prevent corneal detachment.

[0039] In one example, the tissue fixation guidewire 222 is made of a stable metal such as titanium, which can be surgically removed after the cornea has healed. Alternatively, it can be made of a polymer material, such as PMMA as described above, in which case the tissue fixation guidewire 222 does not need to be removed.

[0040] In one example, the tissue fixation guidewire 222 is made of a biodegradable and absorbable biomaterial, so that the tissue fixation guidewire 222 gradually degrades and is absorbed as the cornea heals.

[0041] The front surface of the polymer posterior membrane 1 is hydrophilic, and the rear surface of the polymer posterior membrane 1 is hydrophobic. The purpose of the hydrophilic modification of the front surface is to facilitate the fusion of the polymer posterior membrane 1 with the biological front membrane 2, and the hydrophobic rear surface can reduce the attachment of planktonic cells and proteins in the anterior aqueous humor.

[0042] Example 2

[0043] This embodiment proposes a preparation method for preparing the sutureless composite artificial cornea described in Embodiment 1, comprising the following steps:

[0044] Step 1: Use a micro-precision lathe to process, 3D print or cast a polymer back film 1 with the expected curvature;

[0045] Step 2: Use mold casting, 3D printing or spraying to attach biomaterials to the front surface of polymer back membrane 1 to form bio-front membrane 2;

[0046] Step 3: A tunnel 221 is designed to enter from the top of the peripheral area 22 and exit from the outer edge of the peripheral area 22. Several tunnels 221 are radially distributed in the peripheral area 22.

[0047] Step 4: Insert the tissue fixation guide wire 222 into the tunnel 221.

[0048] Steps one and two of this method are not in an absolute order. Alternatively, the pre-biological membrane 2 can be cast first, followed by the post-polymer membrane 1, as long as the combination of the two can be achieved.

[0049] Example 3

[0050] This embodiment proposes a preparation method for preparing a sutureless composite artificial cornea, including the following steps:

[0051] Step 1: Use a micro-precision lathe to process, 3D print or cast a bio-prepared membrane with the desired curvature 2;

[0052] Step 2: Remove the central part of the posterior surface of the pre-biomembrane 2 in a mushroom-shaped manner, but do not cut through it, keeping the anterior surface of the pre-biomembrane 2 intact, to obtain the pre-biomembrane 2 with a groove structure;

[0053] Step 3: PMMA or PHAMA polymer material is attached to the rear surface of the above-mentioned pre-biofilm 2 with groove structure using mold casting, 3D printing or spraying method to form polymer rear-biofilm 1.

[0054] Step 4: The interface between the polymer post-membrane 1 and the peripheral area 22 of the biological pre-membrane 2 is designed with tunnels 221. The tunnels 221 enter from the top of the biological pre-membrane 2 with the grooved structure and exit from the outer edge of the peripheral area 22. Several tunnels 221 are radially distributed in the peripheral area 22.

[0055] Step 5: Insert the tissue fixation guide wire 222 into the tunnel 221.

[0056] The main difference between this embodiment and Embodiment 2 is that in this embodiment, a biological anterior membrane 2 is fabricated first, and a groove structure is cut out in the center of the posterior surface (i.e., the central area 21) of the biological anterior membrane 2. This groove structure is used for the injection and attachment of polymer materials to form a polymer posterior membrane 1 with a raised structure, which serves as the lens pillar of the "skirt-core structure". Therefore, the biological anterior membrane 2 completely covers the anterior surface of the polymer posterior membrane 1. During the patient's subsequent recovery process, the biological anterior membrane 2 can fuse with the original human tissue, has the apoptosis and self-cleaning function of normal cells, and restores the expected postoperative vision.

[0057] The above embodiments are merely illustrative of the technical concept and features of the present invention, and are intended to enable those skilled in the art to understand the content of the present invention and implement it accordingly. They should not be construed as limiting the scope of protection of the present invention. All equivalent changes or modifications made based on the essence of the content of the present invention should be covered within the scope of protection of the present invention.

Claims

1. A sutureless composite keratoprosthesis, characterized by, The application relates to a high-molecular posterior membrane piece, a biological anterior membrane piece fixed on the front surface of the high-molecular posterior membrane piece, and a plurality of radial tunnels embedded in a peripheral area of the biological anterior membrane piece. The front surface of the high-molecular posterior membrane piece is uniformly provided with integrally-formed filamentous protrusions. The ends of the filamentous protrusions form first bulging parts, thereby enhancing the bonding strength between the biological anterior membrane piece and the high-molecular posterior membrane piece. The tail part of the tissue-fixing guide wire is provided with a barb, and the head part of the tissue-fixing guide wire forms a second bulging part; during the operation, the tissue-fixing guide wire is pushed into the tail part port of the tunnel, and the tissue-fixing guide wire is pierced into the corneal implant bed of a patient, so that the fixation between the artificial cornea and the corneal implant bed is realized, and the corneal astigmatism caused by the suturing operation is avoided.

2. The sutureless composite keratoprosthesis of claim 1, wherein, The material of the biological anterior membrane piece is collagen, hydrogel, silk protein or cellulose.

3. The sutureless composite keratoprosthesis of claim 1, wherein, The material of the high-molecular posterior membrane piece is PMMA or PHEMA.

4. The sutureless composite keratoprosthesis of claim 1, wherein, The tissue-fixing guide wire is made of titanium, a high-molecular material or a degradable and absorbable biological material.

5. The sutureless composite keratoprosthesis of claim 1, wherein, The front surface of the high-molecular posterior membrane piece is subjected to hydrophilic treatment, and the rear surface of the high-molecular posterior membrane piece is subjected to hydrophobic treatment.

6. A production method for producing the sutureless composite keratoprosthesis according to claim 1, characterized by, The application comprises the following steps: The high-molecular posterior membrane piece with an expected curvature is manufactured by using a micro-precision lathe, 3D printing or a casting method; The biological anterior membrane piece is formed by attaching a biological material to the front surface of the high-molecular posterior membrane piece by using a mold casting, 3D printing or spraying method; The tunnels are designed to enter from the top of the peripheral area and exit from the lateral edge of the peripheral area, and a plurality of the tunnels are radially distributed in the peripheral area; The tissue-fixing guide wire is placed into the tunnel.

7. A production method for producing the sutureless composite keratoprosthesis according to claim 1, characterized by, The application comprises the following steps: The biological anterior membrane piece with an expected curvature is manufactured by using a micro-precision lathe, 3D printing or a casting method; The central part of the rear surface of the biological anterior membrane piece is mushroom-shapedly cut off, so that the biological anterior membrane piece with a groove structure is obtained; The high-molecular posterior membrane piece is formed by attaching a high-molecular material to the rear surface of the biological anterior membrane piece by using a mold casting, 3D printing or spraying method; The interface between the high-molecular posterior membrane piece and the peripheral area of the biological anterior membrane piece is designed with the tunnels, the tunnels enter from the top of the biological anterior membrane piece with the groove structure and exit from the lateral edge of the peripheral area, and a plurality of the tunnels are radially distributed in the peripheral area; The tissue-fixing guide wire is placed into the tunnel.

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