Intravascular Stent, Especially for Coronary Vessels

Abstract

An intravascular stent includes cut-outs forming segmented patterns of the stent construction at the same time form the elongated lines of the main segment situated around the longitudinal stent axis and are connected via U-shaped connecting elements. This creates around the longitudinal axis of the stent a geometric pattern resembling a meander of gentle edges, and the two curves in the shape of a the letter V with rounded edges. The stent also includes an oval plate form a connecting segment to connect with the connecting elements of the elongated lines of the main segment, wherein every next main segment is a mirror reflection of the previous segment and in that the curves of the connecting element shaped like the letter V with rounded edges are a mutual mirror reflection in relation to the oval plate of the connecting segment. The stents can include a covering of various drugs.

Claims

1.-17.(canceled)

18. An intravascular stent comprising: a main body in having a form of a tube with a lateral surface and an inner surface, which has a repeated, symmetrical segmented pattern made by cut-outs on the lateral surface of the tube of a continuous material covered with biodegradable and biocompatible polymer comprising substances affecting cells, where the cut-outs forming the segmented patterns of the stent construction at same time form elongated lines of a main segment situated around a longitudinal stent axis and are connected via U-shaped connecting elements thus creating around the longitudinal axis of the stent a geometric pattern resembling a meander of gentle edges, and two curves in having shape of letter V with rounded edges together with an oval plate form a connecting segment to connect with connectors of the elongated lines of the main segment, wherein every next main segment is a mirror reflection of a corresponding previous segment.

19. The intravascular stent of claim 18, wherein V-shaped curves of the connecting segment are a mutual mirror reflection in relation to the oval plate of the connecting segment.

20. The intravascular stent of claim 18, wherein the connecting segments are arranged parallel to each other along a transverse stent axis and are attached alternately to next connector of the elongated lines of the next main segment thus forming an alpha helix pattern.

21. The intravascular stent of claim 18, wherein the connecting segments of the stent are attached to every second connecting element of the elongated lines of the main segment.

22. The intravascular stent of claim 18, wherein some stent segments are extreme main segments, whose every second outer connecting element to connect the elongated lines terminates in gentle passageways with a plate in the shape of a round-point spade.

23. The intravascular stent of claim 22, wherein the oval plates of the connecting segment of the stent or a plate-like ends of the connecting elements to connect the elongated lines of the extreme main segments of the stent in the shape of a round-point spade are oval rings or rings in the shape of a round-point spade to place markers of a reduced transparency for X-rays, especially of platinum or tantalum or gold.

24. The intravascular stent of claim 23, wherein an outer covering of the stent comprises drugs, and in particular the drugs inhibiting cellular proliferation, and forms a layer covering an outer surface of the stent.

25. The intravascular stent of claim 24, wherein the outer covering of the stent takes up to 50%, but not less than 10%, of the outer surface of the stent.

26. The intravascular stent of claim 24, wherein the outer covering of the stent is located centrally, along the outer surface of the stent and includes the elongated lines of the main segment and their connecting elements.

27. The intravascular stent of claim 24, wherein the outer covering of the stent is located centrally on the outer surface of the oval plate or a marker-filled ring of the connecting segment and is shaped in the shape of a + symbol or the letter X.

28. The intravascular stent of claim 24, wherein the outer covering of the stent is located centrally on the outer surface of the plate-like end or a marker-filled ring of the connecting elements to connect the elongated lines of the extreme main stent segments in the shape of a round-point spade and is shaped in the shape of the letter Y n such a manner that the base of the letter connects to the outer covering of the extreme main segments of the stent.

29. The intravascular stent of claim 18, wherein entire inner surface of the stent, including the inner surface of a marker-filled oval ring of the connecting segment of the stent and the inner surface of the marker-filled ring of the connecting elements to connect the elongated lines of the extreme main stent segments in the shape of a round-point spade, is covalently immobilized or in a film with monoclonal anti-CD144 antibodies.

30. The intra vascular stent of claim 18, wherein an inner covering of the stent comprises a system of induction of tropomyosin-1 expression, especially covalent or electrostatic complexes of cell-penetrating peptides together with CRISPR/dCas9 system activating the tropomyosin-1 expression or with expression vectors determining the expression of human recombinant tropomyosin-1, or with stabilized mRNA molecules coding human tropomyosin-1, and forms the layer covering the inner surface of the stent main body.

31. The intravascular stent of claim 30, wherein the inner covering of the stent takes up to 90%, but not less than 50%, of the inner surface of the stent construction element.

32. The intravascular stent of claim 30, wherein the inner covering of the stent is located centrally, along the inner surface of the stent and includes the elongated lines of the main segment and their connectors.

33. The intravascular stent of claim 30, wherein the inner covering of the stent is located centrally on the inner surface of the oval plate or the marker-filled ring of the connecting segment and is shaped in an oval shape.

34. The intravascular stent of claim 30, wherein the inner covering of the stent is located centrally on the inner surface of the plate-like end or a marker-filled ring of the connecting elements to connect the elongated lines of the extreme main segments of the stent and is shaped in the shape of a round-point spade.

Description

EXAMPLE 1

[0040] The skeleton of the intravascular stent is in the form of a tube with cut-outs made on the lateral surface in a continuous material of a tube of AISI 316L austenitic steel. These cut-outs form the stent construction skeleton (1) consisting of alternately arranged main and connecting segments in such a manner that the elongated lines (2) of the main segment (3) are situated along the longitudinal stent axis (4) and are connected via U-shaped connecting elements (5) thus creating around the longitudinal stent axis (4) a geometric pattern resembling a meander of gentle edges, whereas the two curves (6) of the connecting segment (7) are in the shape of a sickle and connect the oval plate (8) of the connecting segment (7) to the connecting elements (5) of the elongated lines (2) of the main segment (3). The advantage of the segmented construction of the stent is its high resistance to external forces, with proper pliability being at the same time maintained. At the same time, the next main segment (9) of the stent is a mirrored reflection of the previous segment (10), while the curves (6) of the connecting segment (7) in the shape of a sickle (6) are a mutual mirrored reflection in relation to the oval plate (8) of the connecting segment (7). The connecting segments (7) are arranged parallel to each other along the transverse stent axis (11) and are attached alternately to the next and every second connecting element (5) of the elongated lines (2) of the next main segment (3) thus forming an alpha helix pattern. The end stent segments are the extreme main segments (12), whose every second outer connecting element (5) to connect the elongated lines (2) terminates in gentle passageways (13) with a plate in the shape of a round-point spade (14).

EXAMPLE 2

[0041] The intravascular stent, especially for coronary vessels, realised as in the first example except that the outer stent surface (16) is coated with everolimus, a drug with inhibitory effect on cellular proliferation. The outer stent covering (15) is applied on the central part of the outer stent plane (16) and includes the elongated lines (2) of the main segment (3) and their connecting elements (5) and takes 30% of the outer surface area (16) of the stent construction element. The outer stent covering (15), comprising everolimus, also includes a central part of the plate-like stent construction elements. In the case of the oval plate (8) of the connecting segment (7) the outer stent covering (15) is applied centrally in the shape of the letter X (17), whereas the outer surface (16) of the plate-like end of the connecting elements (5) to connect the elongated lines (2) of the extreme stent main segments (12) in the shape of a round-point spade (14) is covered with a coating shaped in the shape of letter Y (18) in such a manner that the base of the letter connects to the outer covering (15) of the extreme main segments (12) of the stent. The convex structure of the outer coating (15), comprising everolimus, enters the vessel wall during stent implantation and provides desired penetration of the wall with a view to gradual drug release. On the other hand, the incomplete and centrally arranged covering (15) of the outer surface (16) of the stent provides a more targeted effect of the drug on the cells forming the blood vessel wall, which reduces its negative impact on the re-endothelialization processes of the stent implantation site.

EXAMPLE 3

[0042] The intravascular stent, especially for coronary vessels, realised as in the first example except that the inner surface (19) of its construction is covered with a bilayer accelerating the endothelialization of the stent construction and the re-endothelialization of the stent implantation site, which reduces the possibility of the appearance of restenosis by substantially reducing neointima hyperplasia. The layer localised directly on the stent inner surface are monoclonal anti-CD144 antibodies being covalently immobilised and the layer includes the entire inner surface (19) of the stent construction. The aim of this layer is to interact with the late endothelial progenitor cells circulating in the blood, induce the endothelial cells localised between the stent construction elements to endothelialization of the stent inner surface and positionally stabilise the cells migrating onto the inner surface (19) of the stent. The above layer is partially covered with covalent or electrostatic complexes of complexes of cell-penetrating peptides together with the plasmid DNA of CRISPR/dCas9 system activating the tropomyosin-1 expression (20). This covering is located in the central part of the stent construction elements, taking 70% of their surface area. This coating is located along the inner surface (19) of the stent and includes the elongated lines (2) of the main segment (3) and their connecting elements (5). It also includes the central part of the inner surface (19) of the oval plate (8) of the connecting segment (7) and is shaped in an oval shape (21). The covering is also applied on the central part of the inner surface (19) of the plate-like end of the connecting elements (5) to connect the elongated lines (2) of the extreme main stent segments (12) in the shape of a round-point spade (14), where it is shaped in the shape of a round-point spade (22). The task of the inner covering layer (20) of the stent, the layer localised from the bloodstream side, is to activate the tropomyosin-1 expression in endothelial cells which are positionally stabilised on the inner layer of the covering. The induction of tropomyosin-1 expression by affecting the actin cytoskeleton of endothelial cells will significantly accelerate the pace of their migration while maintaining the efficiently working mechanism of cell-cell type bond formation. Additionally, the covering of the plate-like elements of the stent construction increases the surface area of interaction of cells with the inner stent covering, thus improving the performance of the stent inner coating.

EXAMPLE 4

[0043] The intravascular stent, especially for coronary vessels, realised as in the first or second or third example, with the stent construction being realised by cut-outs from a tube of nickel-titanium alloy. Then the oval plates (8) of the connecting segment (7) of the stent or the plate-like ends of the connecting elements (5) to connect the elongated lines (2) of the extreme segments (12) of the stent in the shape of a round-point spade (14) are oval rings (23) made by cuts in the continuous material or rings (24) in the shape of a round-point spade, in which platinum markers of a reduced transparency for X-rays are placed, which improves the quality of the stent implantation procedure and makes it possible to directly monitor how the stent is arranged with respect to the vessel wall and whether the stent is properly fitted in the stenosis site.

EXAMPLE 5

[0044] The intravascular stent, especially for coronary vessels, realised as in the first or the fourth example, with the outer surface (16) of the stent construction being covered with everolimus, as in the second example, and with the inner surface (19) of the stent construction being covered, as in the third example, with two layers of a biodegradable and biocompatible polymer comprising monoclonal anti-CD144 antibodies and covalent or electrostatic complexes of cell-penetrating peptides together with the plasmid DNA of CRISPR/dCas9 system activating the tropomyosin-1 expression. The outer stent coating in a direct and targeted manner affects the cells forming the blood vessel wall by inhibiting their proliferation. On the other hand, the central arrangement of the coating and incomplete coverage of the outer surface of the stent construction isolates the action of the drug, which does not limit the re-endothelialization processes of the stent implantation site. The inner stent covering, in turn, in a coordinated manner affects the late endothelial progenitor cells and the endothelial cells of the vessels in order to accelerate the pace of the endothelialization of the stent construction and the re-endothelialization of the stent implantation site, which reduces the possibility of the appearance of restenosis by substantially reducing neointima hyperplasia. On the other hand, the covering of the plate-like elements of the stent construction increases the surface area of interaction of the above-mentioned cells, thus improving stent performance.