Reinforced heart valve leaflets

Abstract

A heart valve with reinforced leaflets is provided. The free edge and / or ventral region of the leaflet has circumferentially aligned bands of aligned electrospun fibers with non-aligned fibers. The aligned and / or non-aligned fibers are configured to be bioabsorbable polymer fibers that can be replaced with newly formed tissue over time. A method for fabricating such heart valve leaflets is provided, which involves simultaneously electrospinning using two electrospinning sources to form separate or intermixed layers of aligned and non-aligned fibers.

Description

Technical Field

[0001] The present invention relates to a heart valve for repair.

Background Art

[0002] Since the natural heart valve has a highly organized three-layer structure, it can cope with the forces acting on the heart valve and at the same time can open and close appropriately due to sufficient thinness and flexibility. The natural heart valve consists of three Different layers, each layer having its own structural and functional characteristics and having a preferred arrangement of tissue fibers beneficial to the performance of the heart valve.

[0003] A single-layer prosthetic heart valve or repair heart valve that replaces the natural heart valve is usually made from the pericardium and has limitations in long-term durability. On the other hand, the artificial scaffold of the heart valve cannot fully mimic the mechanical properties of the natural donor scaffold. In the current durability test of valve design, the leaflets mainly tend to break in the radial direction. Therefore, there is a need for a new scaffold material with higher durability while maintaining the desired required mobility. The new scaffold needs to have reinforcing materials with different strengths in different regions / directions. The present invention provides an electrospinning method specialized for heart valves to address at least some of the problems.

Summary of the Invention

Means for Solving the Problems

[0004] In one embodiment, the present invention relates to a method of electrospinning a heart valve leaflet. Aligned fibers are electrospun on a mandrel using a first source. The aligned fibers are configured to be bioabsorbable polymer fibers. Non-aligned fibers are electrospun on the mandrel using a second source. The second source is electrospun simultaneously with the first source, and these non-aligned fibers are configured to be bioabsorbable polymer fibers. The electrospinning of the aligned fibers is at the mandrel DifferentBy electrospinning a patch or region, a band aligned circumferentially around the cardiac valve leaflet is produced. Different The aligned and non-aligned fibers in the patch or region Different are electrospun as layers or a mixed pattern. The circumferentially aligned band is from Joint from Joint to

[0005] and may be provided up to and including the free edge of the cardiac valve leaflet or in the vicinity thereof, or the circumferentially aligned band is used to reinforce the abdominal region of the cardiac valve leaflet. Different In other embodiments, the invention relates to a cardiac valve having at least one leaflet. The free edge of the leaflet comprises or consists essentially of a circumferentially aligned band of aligned electrospun fibers having non-aligned fibers. The aligned fibers are configured to be bioabsorbable polymer fibers, the non-aligned fibers are configured to be bioabsorbable polymer fibers, and the aligned and non-aligned fibers of the free edge

[0006] are in layers or are mixed. Different In yet other embodiments, the invention relates to a cardiac valve having at least one leaflet. The abdominal region of the leaflet comprises or consists essentially of a circumferentially aligned band of aligned electrospun fibers having non-aligned fibers. The aligned fibers are configured to be bioabsorbable polymer fibers, the non-aligned fibers are configured to be bioabsorbable polymer fibers, and the aligned and non-aligned fibers of the free edge

[0007] In embodiments, the bioabsorbable polymer fibers of the aligned fibers may be supramolecular bioabsorbable polymer fibers and / or the bioabsorbable polymer fibers of the non-aligned fibers may be supramolecular bioabsorbable polymer fibers.

[0008] In an embodiment, the aligned fiber bioabsorbable polymer fibers form a porous network that allows cell infiltration, and the porous network containing the infiltrated cells can be replaced by newly formed tissue over time, and / or the non-aligned fibers form a porous network that allows cell infiltration, and the porous network containing the infiltrated cells can be replaced by newly formed tissue over time.

Brief Description of the Drawings

[0009]

Figure 1

Figure 2

Figure 3

Mode for Carrying Out the Invention

[0010] Embodiments of the present invention relate to a method for manufacturing a reinforced heart valve leaflet. In one example, the present invention includes the following method. · Spin aligned and non-aligned fibers simultaneously to form a heart valve that enables endogenous tissue repair (ETR). By spinning simultaneously, it is possible to create a microstructure that enables ETR and improves integrity and adhesiveness. · By using two sources, where one source generates a straight jet and the other source generates random fibers (Figure 3), electrospinning is performed simultaneously. The advantage of the straight jet is that the deposition position can be controlled more precisely. The advantages of performing electrospinning simultaneously using two sources are: (i) the adhesion between the aligned structure and the random structure is improved, and (ii) the porosity is improved by avoiding excessive densification of the aligned regions. The straight jet can also be realized by certain melt extrusion processes (e.g., electrospinning without a voltage difference). · Creation of specific sites where heart valves are reinforced by fibers, made possible by the precise control of the straight jet. For example, along the free edge of the heart valve Joint from Joint to Joint a circumferentially aligned band extending. In other examples, Joint from to

[0011] an artificial electrospun heart valve has at least one layer of aligned fibers and at least one layer of randomly oriented fibers. This approach makes it possible to create a heart valve with mechanical properties that more closely match those of a natural donor scaffold in terms of rigidity and strength.

[0012] In certain embodiments, highly directional aligned fibers are generated, and since the fibers are intermixed with more randomly oriented "normal" electrospun fibers, Different no layers are formed. This results in the formation of a heart valve tip tissue where the aligned and non-aligned fibers are directly bonded and intertwined with each other.

[0013] In other embodiments, the aligned fibers are DifferentGenerated in the region, as a result, it strengthens the tissue of the heart valve. Thereby, it may be alternately arranged with the misaligned fibers Different A patch or band-like structure is obtained.

[0014] In yet other embodiments, the aligned fibers are manufactured simultaneously with the misaligned fibers, so that a stronger interaction and adhesion occur between the aligned fibers and the misaligned fibers, which helps prevent delamination and can provide a more optimal distribution of local porosity (for cell engraftment and ETR).

[0015] In yet other embodiments, the aligned fibers are manufactured in the form of a straight jet, thereby enabling a more controlled volume.

[0016] In yet another embodiment, the straight jet for manufacturing the aligned fibers is manufactured through a melt extrusion process, an electrospinning process, or a winding process.

[0017] In yet other embodiments, the aligned fibers form a circumferentially aligned band that extends along the free edge of the heart valve leaflet Joint from Joint to

[0018] In yet other embodiments, the aligned fibers Joint from Joint to

[0019] form a set of curved circumferentially aligned bands / bundles that extend along the entire edge.

[0020] In yet other embodiments, to optimize the balance between the durability and flexibility of the valve leaflet, the aligned fibers are deposited on the valve leaflet in the form of a band or bundle.

[0021] In yet other embodiments, the aligned fibers may contain either an absorbent material or a non-absorbent material.

[0022] In yet other embodiments, the aligned fibers may be, for example, suture wires made from ultra-high molecular weight polyethylene (UHMWPE).

[0023] By spinning the fibers more circumferentially, the durability of these heart valves is increased. The aligned fibers may be defined locally or may be dispersed. As the circumferential force applied to the valve tip increases, it may cause damage to the valve tip, so alignment in a preferred direction may be performed. For example, circumferential reinforcement is preferred. The region of aligned fibers may be defined locally or may be dispersed over the entire region, aligned in a preferred direction, and / or dispersed as a patch or along the entire scaffold. This approach strengthens the valve tip, resulting in improved durability. They may be reinforced by aligned fibers in various ways, such as (bioabsorbable) wires, locally aligned fibers, or bands.

[0024] The aligned fibers may differ in diameter, material, or other properties. Optionally, the aligned fiber polymer may differ from the non-aligned fiber polymer. The aligned fiber polymer may optionally be selected to be more or less bioabsorbable.

[0025] By using bioabsorbable wires, the circumferential strength of a site is improved. These wires are absorbed over time like the other parts of the heart valve, but provide support to prevent lacerations during the initial ETR. The aligned wires may be sutured through the bonding surface of the valve tip or attached by other methods. A circumferentially aligned band that supports the valve tip also prevents breakage. Alternatively, for example, during or after manufacture, aligned edges or rims may be added onto or within the scaffold by directly electrospinning on the scaffold.

[0026] In one example, the aligned and non-aligned fibers may be woven and / or bonded to each other.

[0027] In the method shown in FIG. 3, in addition to the non-aligned fibers produced by the first polymer source, a second polymer source is employed that is used to apply aligned fibers during manufacture. These aligned fibers may be electrospun using other power sources or drawn from continuous droplets supplied from a pump. This enables very precise alignment in the deposition region. Using this method, it becomes possible to perform spin processing in a specific direction on a target with a complex shape for fabricating a heart valve.

[0028] The electrospun materials referred to herein may include a ureidopyrimidinone (UPy) quadruple hydrogen bonding motif (pioneer Sijbesma (1997), Science 278, 1601-1604) and a polymer backbone selected from the group including, for example, biodegradable polyesters, polyurethanes, polycarbonates, poly(orthoesters), polyphosphate esters, polyanhydrides, polyphosphazenes, polyhydroxyalkanoates, polyvinyl alcohol, polypropylene fumarate. Examples of polyesters include polycaprolactone, poly(L-lactide), poly(DL-lactide), poly(valerolactone), polyglycolide, polydioxanone, and their copolyesters. Examples of polycarbonates include poly(trimethylene carbonate), poly(dimethyltrimethylene carbonate), poly(hexamethylene carbonate).

[0029] Even non-supramolecular polymers can achieve similar results if their properties are carefully selected and the materials are processed to ensure the required surface properties. These polymers may include biodegradable or non-biodegradable polyesters, polyurethanes, polycarbonates, poly(orthoesters), polyphosphate esters, polyanhydrides, polyphosphazenes, polyhydroxyalkanoates, polyvinyl alcohol, polypropylene fumarate, and the like. Examples of polyesters include polycaprolactone, poly(L-lactide), poly(DL-lactide), poly(valerolactone), polyglycolide, polydioxanone, and their copolyesters. Examples of polycarbonates include poly(trimethylene carbonate), poly(dimethyltrimethylene carbonate), poly(hexamethylene carbonate), and the like.

Claims

1. 1. A method of electrospinning a cardiac valve leaflet, comprising: (a) electrospinning aligned fibers of bioabsorbable polymer fibers onto a mandrel using a first source; (b) electrospinning non-aligned fibers of bioabsorbable polymer fibers onto the mandrel using a second source simultaneously with the first source; The electrospinning of the aligned fibers produces circumferentially aligned bands of the cardiac valve leaflets by electrospinning distinct patches or regions on the mandrel, and the aligned and non-aligned fibers in the distinct patches or regions are electrospun either in distinct layers or in a mixed pattern.

2. The method of claim 1, wherein the bioabsorbable polymer fibers of the aligned fibers are configured to be supramolecular bioabsorbable polymer fibers and / or the bioabsorbable polymer fibers of the non-aligned fibers are configured to be supramolecular bioabsorbable polymer fibers.

3. 10. The method of claim 1, wherein the circumferentially aligned bands extend from a free edge of the heart valve leaflet or from commissure to commissure near the free edge, or the circumferentially aligned bands are used to reinforce the abdominal region of the heart valve leaflet.

4. 2. The method of claim 1, wherein the bioabsorbable polymer fibers of the aligned fibers form a porous network that allows cell infiltration, and the porous network containing the infiltrated cells is replaced with newly formed tissue over time, and / or the bioabsorbable polymer fibers of the unaligned fibers form a porous network that allows cell infiltration, and the porous network containing the infiltrated cells is replaced with newly formed tissue over time.

5. 1. A heart valve comprising at least one leaflet, A heart valve, wherein the free edge of the valve leaflet essentially comprises circumferentially aligned bands of aligned electrospun fibers including non-aligned fibers, the aligned fibers being configured to be bioabsorbable polymer fibers, the non-aligned fibers being configured to be bioabsorbable polymer fibers, and the aligned fibers and non-aligned fibers of the free edge being either separate layers or intermixed.

6. The heart valve of claim 5, wherein the bioabsorbable polymer fibers of the aligned fibers are configured to be supramolecular bioabsorbable polymer fibers, and / or the bioabsorbable polymer fibers of the non-aligned fibers are configured to be supramolecular bioabsorbable polymer fibers.

7. 6. The heart valve of claim 5, wherein the bioabsorbable polymer fibers of the aligned fibers form a porous network that allows cell infiltration, and the porous network containing the infiltrated cells is replaced with newly formed tissue over time, and / or the bioabsorbable polymer fibers of the unaligned fibers form a porous network that allows cell infiltration, and the porous network containing the infiltrated cells is replaced with newly formed tissue over time.

8. 1. A heart valve comprising at least one leaflet, A heart valve, wherein the abdominal region of the valve leaflet essentially comprises circumferentially aligned bands of aligned electrospun fibers including non-aligned fibers, the aligned fibers being configured to be bioabsorbable polymer fibers, the non-aligned fibers being configured to be bioabsorbable polymer fibers, and the aligned fibers and non-aligned fibers at the free edge being configured to be either separate layers or intermixed.

9. The heart valve of claim 8, wherein the bioabsorbable polymer fibers of the aligned fibers are configured to be supramolecular bioabsorbable polymer fibers, and / or the bioabsorbable polymer fibers of the non-aligned fibers are configured to be supramolecular bioabsorbable polymer fibers.

10. 9. The heart valve of claim 8, wherein the bioabsorbable polymer of the aligned fibers forms a porous network that allows cell infiltration, and the porous network containing the infiltrated cells is replaced over time by newly formed tissue, and / or the bioabsorbable polymer fibers of the unaligned fibers form a porous network that allows cell infiltration, and the porous network containing the infiltrated cells is replaced over time by newly formed tissue.

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