Abstract
The presently-disclosed subject matter relates to adsorptive radiocontrast constructs in multiple advantageous structural embodiments, which are designed to possess dual therapeutic and diagnostic actions. A concomitant therapeutic antiplatelet, as well as vasodilatation, effects, and a diagnostic real-time continuous visualization of an artery, can be obtained via direct injection of the constructs into said artery using a suitable catheter during procedural angiography with or without percutaneous intervention.
Claims
1. An adsorptive radiocontrast construct with dual therapeutic and diagnostic actions, comprising: a radiodense nucleus, and one or more adhesive arms tethered to said radiodense nucleus with or without a linker.
2. The adsorptive radiocontrast construct according to claim 1, wherein the radiodense nucleus comprises an element or molecule that is capable of absorbing or altering external electromagnetic radiation resulting in decreased exposure on an electromagnetic waves detector.
3. The adsorptive radiocontrast construct according to claim 1, wherein the adhesive arms comprise peptide motifs or peptidomimetics that bind to their corresponding receptors of cell-adhesion molecules.
4. The adsorptive radiocontrast construct according to claim 1, wherein the linker is a flexible molecule or a stretch of molecule of different lengths or polarity that can possess a branching capability, and can be used to link two or more molecules of interest together.
5. The adsorptive radiocontrast construct according to claim 1, whereby a concomitant therapeutic antiplatelet effect and a diagnostic real-time continuous visualization of an artery can be obtained via direct injection of the adsorptive radiocontrast constructs using a suitable catheter.
6. The adsorptive radiocontrast construct according to claim 1, wherein one or more additional therapeutically active molecules can be incorporated into its molecular structure, so that said additional therapeutically active molecules can be tethered to the radiodense nucleus, or anchored to or replace the linker.
7. The adsorptive radiocontrast construct according to claim 1, wherein the radiodense nucleus can be tethered to one adhesive arm resulting in a monovalent adsorptive radiocontrast construct, or can be tethered to multiple adhesive arms resulting in a multivalent adsorptive radiocontrast construct.
8. The adsorptive radiocontrast construct according to claim 1, wherein the adhesive arms can be identical resulting in a monospecific adsorptive radiocontrast construct, or different resulting in a polyspecific adsorptive radiocontrast construct.
9. The adsorptive radiocontrast construct according to claim 1, can be used for procedural real-time angiography with or without percutaneous intervention.
10. An adsorptive radiocontrast construct with dual therapeutic and diagnostic actions, comprising one or more adhesive peptides or peptidomimetics that contain within its molecular structure a radiodense element or molecule.
11. The adsorptive radiocontrast construct according to claim 10, wherein the adhesive peptides or peptidomimetics bind to their corresponding receptors of cell-adhesion molecules.
12. The adsorptive radiocontrast construct according to claim 10, wherein the radiodense element or molecule is capable of absorbing or altering external electromagnetic radiation resulting in decreased exposure on an electromagnetic waves detector.
13. The adsorptive radiocontrast construct according to claim 10, wherein the adhesive peptides or peptidomimetics, that contain within its molecular structure a radiodense element or molecule, can be singles resulting in a monovalent adsorptive radiocontrast construct, or can be multiple tethered to each other with flexible linkers resulting in a multivalent adsorptive radiocontrast construct.
14. The adsorptive radiocontrast construct according to claim 10, wherein the adhesive peptides or peptidomimetics, that contain within its molecular structure a radiodense element or molecule, can be identical resulting in a monospecific adsorptive radiocontrast construct, or different resulting in a polyspecific adsorptive radiocontrast construct.
15. A multivalent adsorptive radiocontrast nanoconstruct with dual therapeutic and diagnostic actions, comprising: a radiodense nanocore, that is coated with a coat of pluralities of adhesive peptides or peptidomimetics with or without a subcoat of linkers, wherein said pluralities of adhesive peptides or peptidomimetics are presented to interact simultaneously with multiple corresponding binding sites.
16. The multivalent adsorptive radiocontrast nanoconstruct according to claim 15, wherein the radiodense nanocore comprises an element or molecule that is capable of absorbing or altering external electromagnetic radiation resulting in decreased exposure on an electromagnetic waves detector.
17. The multivalent adsorptive radiocontrast nanoconstruct according to claim 15, wherein the pluralities of adhesive peptides or peptidomimetics bind to their corresponding receptors of cell-adhesion molecules.
18. The multivalent adsorptive radiocontrast nanoconstruct according to claim 15, wherein the subcoat of linkers can comprise a biodegradable layer of fluidic material to which the pluralities of adhesive peptides or peptidomimetics are tethered, whereby the pluralities of adhesive peptides or peptidomimetics retain unrestricted mobility, efficient clustering, and redistribution.
19. The multivalent adsorptive radiocontrast nanoconstruct according to claim 15, wherein the pluralities of adhesive peptides or peptidomimetics, can be identical resulting in a monospecific multivalent adsorptive radiocontrast nanoconstruct, or different resulting in a polyspecific multivalent adsorptive radiocontrast nanoconstruct.
20. The multivalent adsorptive radiocontrast nanoconstruct according to claim 15, can be a nanosphere or a nanoparticle with anisometric dimensions.
Description
SUMMARY OF THE DRAWINGS
[0025] FIG. 1 describes basic structures of multiple embodiments of the proposed adsorptive radiocontrast constructs (ARCs).
[0026] FIG. 2 describes a basic method of preparation of the proposed adsorptive radiocontrast constructs (ARCs).
[0027] FIG. 3 describes a structure of a monovalent embodiment of the proposed adsorptive radiocontrast constructs (ARCs).
[0028] FIG. 4 describes a linker-containing structure of a monovalent embodiment of the proposed adsorptive radiocontrast constructs (ARCs).
[0029] FIG. 5a describes a vasodilator-incorporated structure of a linker-containing monovalent embodiment of the proposed adsorptive radiocontrast constructs (ARCs).
[0030] FIG. 5b describes a different vasodilator-incorporated structure of a linker-containing monovalent embodiment of the proposed adsorptive radiocontrast constructs (ARCs).
[0031] FIG. 6 describes an iodinated-linker structure of a monovalent embodiment of the proposed adsorptive radiocontrast constructs (ARCs).
[0032] FIG. 7 describes a structure of a monospecific bivalent embodiment of the proposed adsorptive radiocontrast constructs (ARCs).
[0033] FIG. 8 describes a structure of a polyspecific bivalent embodiment of the proposed adsorptive radiocontrast constructs (ARCs).
[0034] FIG. 9 describes a structure of a monospecific trivalent embodiment of the proposed adsorptive radiocontrast constructs (ARCs).
[0035] FIG. 10 describes a structure of a monospecific quadrivalent embodiment of the proposed adsorptive radiocontrast constructs (ARCs).
[0036] FIG. 11 describes two structures of the proposed adsorptive radiocontrast constructs (ARCs) that comprise different radiodense nuclei.
[0037] FIG. 12 describes the iodination of an adhesive peptidomimetic representing an embodiment of a basic method of preparation of the proposed adsorptive radiocontrast constructs (ARCs).
[0038] FIG. 13 describes a cyclic structure of an iodinated adhesive peptide representing a monovalent embodiment of the proposed adsorptive radiocontrast constructs (ARCs).
[0039] FIG. 14 describes a structure of two linked iodinated adhesive peptidomimetics representing a monospecific bivalent embodiment of the proposed adsorptive radiocontrast constructs (ARCs).
[0040] FIG. 15 describes a structure of two linked different iodinated adhesive peptides representing a polyspecific bivalent embodiment of the proposed adsorptive radiocontrast constructs (ARCs).
[0041] FIG. 16 describes a structure of four linked iodinated adhesive peptidomimetics representing a monospecific quadrivalent embodiment of the proposed adsorptive radiocontrast constructs (ARCs).
[0042] FIG. 17 describes a structure of four linked different iodinated adhesive peptides representing a polyspecific quadrivalent embodiment of the proposed adsorptive radiocontrast constructs (ARCs).
[0043] FIG. 18a describes a vasodilator-containing structure of an iodinated adhesive peptidomimetic representing a monovalent embodiment of the proposed adsorptive radiocontrast constructs (ARCs).
[0044] FIG. 18b describes a vasodilator-containing structure of two linked iodinated adhesive peptidomimetics representing a monospecific bivalent embodiment of the proposed adsorptive radiocontrast constructs (ARCs).
[0045] FIG. 19 depicts a schematic description of the interaction of the proposed adsorptive radiocontrast constructs (ARCs) with the arterial wall at the microscopic level combined with the corresponding result at the macroscopic level.
[0046] FIG. 20 describes a basic method of preparation of the proposed multivalent adsorptive radiocontrast nanoconstructs (MARCs).
[0047] FIG. 21a depicts a schematic description showing the diblock structure of the proposed multivalent adsorptive radiocontrast nanoconstructs (MARCs).
[0048] FIG. 21b depicts a schematic description showing the triblock structure of the proposed multivalent adsorptive radiocontrast nanoconstructs (MARCs).
[0049] FIG. 22 depicts a schematic description of the interaction of the proposed multivalent adsorptive radiocontrast nanoconstructs (MARCs) with the arterial wall at the microscopic level combined with the corresponding result at the macroscopic level.
DETAILED DESCRIPTION OF THE DRAWINGS
[0050] Referring to the drawings in more detail; which describe different embodiments of the structure, synthesis, usage, and mechanism of action of the proposed ARCs. FIG. 1 describes different embodiments of the ARCs basic structure. Structure A depicts a simple structure of the ARCs, wherein an iodinated functional group (Ri), representing the radiodense nucleus, is tethered to a cell-adhesive peptide motif or peptidomimetic (Rs), representing the adhesive arm, via an amide bond. Structure B depicts a multivalent structure of the proposed ARCs, wherein an iodinated functional group (Ri), representing the radiodense nucleus, is tethered to an (n) number of cell-adhesive peptide motifs or peptidomimetics (Rs), representing the adhesive arms, via amide bonds. Structure C depicts a polyspecific bivalent structure of the proposed ARCs, wherein an iodinated functional group (Ri), representing the radiodense nucleus, is tethered to two different cell-adhesive peptide motifs or peptidomimetics (Rs1 and Rs2), representing two different adhesive arms, via amide bonds. Structure D depicts a monovalent structure of the proposed ARCs with a linker, wherein an iodinated functional group (Ri), representing the radiodense nucleus, is tethered via a linker (R) to a cell-adhesive peptide motif or peptidomimetic (Rs), representing the adhesive arm via amide bonds. Structure E depicts a monovalent structure of the proposed ARCs with a linker, wherein iodine (I), representing the radiodense nucleus, is covalently bound to a linker (R) which—in turn—is tethered to a cell-adhesive peptide motif or peptidomimetic (Rs), representing the adhesive arms via an amide bond. Structure F depicts a monovalent structure of the proposed ARCs with a linker, wherein a nitrate ester, representing an additional therapeutically active molecule, is tethered to an iodinated functional group (Ri), representing the radiodense nucleus, which—in turn—is tethered via a linker (R) to a cell-adhesive peptide motif or peptidomimetic (Rs), representing the adhesive arm via amide bonds. Structure G depicts a monovalent structure of the proposed ARCs with a linker, wherein a nitrate ester, representing an additional therapeutically active molecule, is tethered to the linker (R) which links between an iodinated functional group (Ri), representing the radiodense nucleus, and a cell-adhesive peptide motif or peptidomimetic (Rs) representing the adhesive arm. Structure H depicts a monospecific bivalent structure of the proposed ARCs with a linker, wherein said linker (R) tethers two iodinated cell-adhesive domains (iRs), representing the adhesive peptides or peptidomimetics, that contain within its molecular structure a radiodense element or molecule. Structure I depicts a polyspecific trivalent structure of the proposed ARCs with a branched linker, wherein said branched linker (NR3) tethers three different iodinated cell-adhesive domains (iRs1 and iRs2) representing the adhesive peptides or peptidomimetics that contain within its molecular structure a radiodense element or molecule.
[0051] FIG. 2 describes a basic method of preparation of the proposed ARCs, wherein an iodinated molecule (herein an iodinated carboxylic acid, Ri-COOH) is reacting with a cell-adhesive domain (H2N-Rs) using a catalyst resulting in an ARC, which comprises an iodinated radiodense nucleus linked to an adhesive arm, and a water molecule.
[0052] FIG. 3 describes a structure of a monovalent embodiment of the proposed ARCs. The figure depicts the skeletal formula followed by the space-filling calotte model below. As shown, the monovalent ARC comprises a radiodense nucleus, comprising an iodine-containing molecule, covalently bound to an adhesive arm comprising the cell-adhesive peptide motif of integrin-binding RGD tripeptide. The advantages of this structure comprise the aimed dual therapeutic and diagnostic actions, wherein the cell-adhesive peptide motif of integrin-binding RGD tripeptide can adsorb to the endothelial layer of the arterial wall, especially if diseased since the adsorption capacity is directly proportional to the disease state of the arterial wall, for longer duration post-injection via a suitable catheter, so that the iodine-containing radiodense nucleus continuously marks the arterial wall during a digitalized X-ray based real-time visualization. This diagnostic action is advantageous during real-time angiography, especially if a percutaneous intervention is performed. Additionally, the cell-adhesive peptide motif of integrin-binding RGD tripeptide competitively interacts with its corresponding receptor of αIIbβ3 which is a highly abundant heterodimeric platelet receptor that usually binds to fibrinogen with augmented affinity upon platelet activation. This therapeutic antiplatelet action is advantageous during percutaneous intervention, especially in the case of (I) primary intervention during acute myocardial infarction to prevent the no-reflow phenomenon, (II) insufficient patient loading with an antiplatelet drug prior to PCI, and (III) heavy thrombus burden during intervention.
[0053] FIG. 4 describes a linker-containing structure of a monovalent embodiment of the proposed ARCs, wherein a linker is integrated between an iodine-containing radiodense nucleus and an adhesive arm. The figure depicts the skeletal formula followed by the space-filling calotte model below. As shown, the iodine-containing radiodense nucleus is linked, via a linker formed of an (n) number of flexible glycine (G) sequence(s), to an adhesive arm comprising the cell-adhesive peptide motif of integrin-binding RGD tripeptide. The advantages of this structure comprise the previously mentioned dual therapeutic and diagnostic actions, in addition to the molecular flexibility and spacing provided by the flexible linker, so that decreasing the steric hindrance by improving the spatial arrangement of the proposed ARCs during interaction with their corresponding receptors of cell-adhesion molecules.
[0054] FIG. 5a describes a vasodilator-incorporated structure of a linker-containing monovalent embodiment of the proposed ARCs, wherein a nitrate ester (a vasodilator prodrug), representing an additional therapeutically active molecule, is tethered to a radiodense nucleus containing iodine, which—in turn—is tethered via a linker to an adhesive arm of cell-adhesive peptide motif or peptidomimetic. The figure depicts the skeletal formula followed by the space-filling calotte model below. As shown, the nitrate ester-containing iodinated radiodense nucleus is linked, via a linker formed of an (n) number of flexible glycine (G) sequence(s), to an adhesive arm comprising the cell-adhesive peptide motif of integrin-binding RGD tripeptide. The advantages of this structure comprise the previously mentioned dual therapeutic and diagnostic actions, besides an additional therapeutic effect of vasodilatation which decreases arterial spasm precipitated by manipulation during interventions. Likewise, the composite nature of the structure of the proposed ARCs can permit a supplementary therapeutic effect that can be obtained via therapeutically active metabolites of said ARCs (herein, traces of the antiplatelet/anti-inflammatory salicylic acid). Moreover, the proposed structure retains the molecular flexibility and spacing provided by the flexible linker, decreasing the steric hindrance by improving the spatial arrangement of the ARCs during interacting with their corresponding receptors of cell-adhesion molecules.
[0055] FIG. 5b describes a different vasodilator-incorporated structure of a linker-containing monovalent embodiment of the proposed ARCs, wherein a nitrate ester (a vasodilator prodrug), representing an additional therapeutically active molecule, is anchored to a linker that tethers a radiodense nucleus and an adhesive arm. The figure depicts the skeletal formula followed by the space-filling calotte model below. As shown, the nitrate ester-containing PEG (polyethylene glycol) linker tethers a radiodense nucleus comprising an iodinated molecule to an adhesive arm comprising the cell-adhesive peptide motif of integrin-binding RGD tripeptide. The advantages of this structure comprise the previously mentioned dual therapeutic and diagnostic actions, besides an additional therapeutic effect of vasodilatation which decreases arterial spasm precipitated by manipulation during interventions. Also, the proposed structure retains the molecular flexibility and spacing provided by the PEG linker, so that decreasing the steric hindrance.
[0056] FIG. 6 describes a linker-containing structure of a monovalent embodiment of the proposed ARCs, wherein a linker is integrated between a radiodense nucleus of elemental iodine and an adhesive arm. The figure depicts the skeletal formula followed by the space-filling calotte model below. As shown, an iodinated PEG linker is tethered to an adhesive arm comprising the cell-adhesive peptide motif of integrin-binding RGD tripeptide. The advantages of this structure retain the previously mentioned dual therapeutic and diagnostic actions, in addition to the molecular flexibility and spacing provided by the flexible linker, so that decreasing the steric hindrance by improving the spatial arrangement of the ARCs during interaction with their corresponding receptors of cell-adhesion molecules. As well as, replacing the bulky radiodense nucleus of an iodinated molecule with elemental iodine tethered directly to the linker, further reduces the steric hindrance.
[0057] FIG. 7 describes a structure of a monospecific bivalent embodiment of the proposed ARCs. The figure depicts the skeletal formula followed by the space-filling calotte model below. As shown, the monospecific bivalent ARC comprises a radiodense nucleus of an iodine-containing molecule covalently bound to two adhesive arms comprising the cell-adhesive peptide motif of integrin-binding RGD tripeptides. The advantages of this structure retain the previously mentioned dual therapeutic and diagnostic actions, but with an augmented functional affinity that is achieved by the bivalency.
[0058] FIG. 8 describes a structure of a polyspecific bivalent embodiment of the proposed ARCs. The figure depicts the skeletal formula followed by the space-filling calotte model below. As shown, the polyspecific bivalent ARC comprises an iodine-containing radiodense nucleus covalently bound to two adhesive arms comprising two integrin-binding cell-adhesive peptide motifs of RGD tripeptide and REDV quadripeptide. The advantages of this structure retain the previously mentioned dual therapeutic and diagnostic actions, but with an augmented functional affinity that is achieved by the bivalency. Additionally, the polyspecificity expands the pool of corresponding receptors available for the ARC, wherein in the provided embodiment of FIG. 8, the RGD tripeptide has an augmented affinity for α3β1, α5β1, α8β1, αvβ1, αvβ3, αvβ5, αvβ6, αIIbβ3 integrin receptors, while the REDV quadripeptide has an augmented affinity for α4β1 integrin receptor.
[0059] FIG. 9 describes a structure of a monospecific trivalent embodiment of the proposed ARCs. The figure depicts the skeletal formula followed by the space-filling calotte model below. As shown, the monospecific trivalent ARC comprises an iodine-containing radiodense nucleus covalently bound to three adhesive arms comprising three integrin-binding cell-adhesive peptide motifs of RGD tripeptides. The advantages of this structure retain the previously mentioned dual therapeutic and diagnostic actions, but with the multivalency-related augmented functional affinity that is achieved by the trivalency.
[0060] FIG. 10 describes a structure of a monospecific quadrivalent embodiment of the proposed ARCs. The figure depicts the skeletal formula followed by the space-filling calotte model below. As shown, the monospecific quadrivalent ARC comprises an iodine-containing radiodense nucleus covalently bound to four adhesive arms comprising four integrin-binding cell-adhesive peptide motifs of RGD tripeptides. The advantages of this structure retain the previously mentioned dual therapeutic and diagnostic actions, but with an augmented functional affinity that is achieved by the quadrivalency, as an example of multivalency.
[0061] FIG. 11 describes two different structures of the ARCs wherein the radiodense nucleus is different in each structure. For each structure, the figure depicts the skeletal formula followed by the space-filling calotte model below it. As shown in each structure, the ARC comprises an iodine-containing radiodense nucleus covalently bound to one or more adhesive arms comprising integrin-binding cell-adhesive peptide motifs of RGD tripeptides. These structures aim to emphasize the variability of the radiodense nucleus that can be used in the structure of the proposed ARCs, providing that they achieve the condition of radiodensity. And likewise, variable cell-adhesive peptide motifs, or peptidomimetics, can be used as adhesive arms in the structure of the proposed ARCs, as long as they achieve the condition of adsorptive/adhesive fixation.
[0062] FIG. 12 describes a basic method of preparation of the proposed ARCs, wherein the iodination of an adhesive peptide/peptidomimetic represents another embodiment of such method of preparation. As shown, an adhesive peptide/peptidomimetic (herein 1-R benzene, R-C6H5), comprising a cell-adhesive domain, is reacting with iodine (12) using a catalyst in an electrophilic iodination reaction to produce an ARC that comprises an adhesive peptide/peptidomimetic that contains within its molecular structure a radiodense element (herein, iodine) and hydrogen iodide.
[0063] FIG. 13 describes the cyclic structure of an iodinated adhesive peptide representing a monovalent embodiment of the proposed ARCs. The figure depicts the skeletal formula followed by the space-filling calotte model below. As shown, the monovalent ARC comprises an iodine-containing adhesive peptide comprising the integrin-binding cell-adhesive domain of the iodinated cyclic RGDyK peptide. The advantages of this structure retain the previously mentioned dual therapeutic and diagnostic actions, but with augmented stability and affinity that are achieved by the cyclic structure.
[0064] FIG. 14 describes a structure of two linked iodinated adhesive peptidomimetics representing a monospecific bivalent embodiment of the proposed ARCs, wherein a linker is integrated between two iodinated adhesive peptidomimetics to form a flexible ARC. The figure depicts the skeletal formula followed by the space-filling calotte model below. As shown, the monospecific bivalent ARC comprises two linked (via a PEG linker) iodine-containing adhesive peptidomimetics comprising the integrin-binding cell-adhesive domain of iodinated RGD-peptidomimetics. The advantages of this structure retain the previously mentioned dual therapeutic and diagnostic actions, but with an augmented functional affinity that is achieved by the flexible bivalency, which—in turn—is achieved via the molecular flexibility and spacing provided by the flexible linker, so that decreasing the steric hindrance by improving the spatial arrangement of the ARCs during interacting with their corresponding receptors of cell-adhesion molecules.
[0065] FIG. 15 describes a structure of two linked different iodinated adhesive peptides/peptidomimetics representing a polyspecific bivalent embodiment of the proposed ARCs, wherein a linker is integrated between an iodinated adhesive peptidomimetic and an iodinated adhesive peptide to form a flexible ARC. The figure depicts the skeletal formula followed by the space-filling calotte model below. As shown, the polyspecific bivalent ARC comprises an iodinated adhesive RGD-peptidomimetic linked (via a PEG linker) to an iodine-containing adhesive peptide comprising the integrin-binding cell-adhesive domain of iodinated cyclic RGDyK. The advantages of this structure retain the previously mentioned dual therapeutic and diagnostic actions, but with an augmented functional affinity that is achieved by the flexible bivalency, which—in turn—is achieved via the molecular flexibility and spacing provided by the flexible linker, so that decreasing the steric hindrance. Moreover, the polyspecificity expands the pool of corresponding receptors available for the ARC.
[0066] FIG. 16 describes a structure of four linked iodinated adhesive peptidomimetics representing a monospecific quadrivalent embodiment of the proposed ARCs, wherein a branched linker is integrated between four iodinated adhesive peptidomimetics to form a flexible ARC. The figure depicts the skeletal formula followed by the space-filling calotte model below. As shown, the monospecific quadrivalent ARC comprises four linked (via a branched PEG linker) iodine-containing adhesive peptidomimetics comprising the integrin-binding cell-adhesive domain of iodinated RGD-peptidomimetics. The advantages of this structure retain the previously mentioned dual therapeutic and diagnostic actions, but with an augmented functional affinity that is achieved by the flexible quadrivalency, which—in turn—is achieved via the molecular flexibility and spacing provided by the branched flexible linker, so that decreasing the steric hindrance.
[0067] FIG. 17 describes a structure of four linked different iodinated adhesive peptides/peptidomimetics representing a polyspecific quadrivalent embodiment of the proposed ARCs, wherein a branched linker is integrated between three iodinated adhesive peptidomimetics and an iodinated adhesive peptide to form a flexible ARC. The figure depicts the skeletal formula followed by the space-filling calotte model below. As shown, the polyspecific quadrivalent ARC comprises three iodinated adhesive RGD-peptidomimetic linked (via a branched PEG linker) to an iodine-containing adhesive peptide comprising the integrin-binding cell-adhesive domain of iodinated cyclic RGDyK. The advantages of this structure retain the previously mentioned dual therapeutic and diagnostic actions, but with an augmented functional affinity that is achieved by the flexible quadrivalency, which—in turn—is achieved via the molecular flexibility and spacing provided by the branched flexible linker, so that decreasing the steric hindrance. Also, the polyspecificity expands the pool of corresponding receptors available for the ARC.
[0068] FIG. 18a describes a vasodilator-containing structure of an iodinated adhesive peptidomimetic representing a monovalent embodiment of the proposed ARCs, wherein a nitrate ester (a vasodilator prodrug), representing an additional therapeutically active molecule, is anchored to the molecular structure of the iodinated adhesive peptide/peptidomimetic. The figure depicts the skeletal formula followed by the space-filling calotte model below. As shown, the nitrate ester is tethered to the iodine-containing adhesive peptide comprising the integrin-binding cell-adhesive domain of iodinated RGD-peptidomimetic. The advantages of this structure comprise the previously mentioned dual therapeutic and diagnostic actions, besides an additional therapeutic effect of vasodilatation which decreases arterial spasm precipitated by manipulation during interventions.
[0069] FIG. 18b describes a vasodilator-containing structure of two linked iodinated adhesive peptidomimetics representing a monospecific bivalent embodiment of the proposed ARCs, wherein a nitrate ester (a vasodilator prodrug), representing an additional therapeutically active molecule, is anchored to the linker that tethers two iodinated adhesive peptide/peptidomimetics. The figure depicts the skeletal formula followed by the space-filling calotte model below. As shown, the nitrate ester is tethered to the PEG linker that links two iodine-containing adhesive peptidomimetics comprising the integrin-binding cell-adhesive domain of iodinated RGD-peptidomimetics. The advantages of this structure comprise the previously mentioned dual therapeutic and diagnostic actions, besides an additional therapeutic effect of vasodilatation which decreases arterial spasm precipitated by manipulation during interventions. Also, the proposed structure retains the molecular flexibility and spacing provided by the PEG linker, so that decreasing the steric hindrance.
[0070] FIG. 19 depicts a schematic description of the basic mechanism of action of the proposed ARCs 16, wherein the interaction of said ARCs 16 with a target cell 12 of the inner arterial wall is shown at the microscopic level, combined with the corresponding result at the macroscopic level. Said target cell 12 presents surface receptors in the form of cell-adhesion molecules (not shown), preferentially integrins, and during the injection phase 24, the ARCs 16 are rushed through the bloodstream 14 due to elevated intra-arterial pressure (normally, 120 mmHg during systole). Then, a subsequent illumination phase 26 follows, wherein a considerable amount of the injected ARCs 16 interacts with the target cells 12 of the inner arterial wall leading to adsorptive/adhesive fixation. This fixation results from the simultaneous interaction between the adhesive arms 18 of each ARC 16 with one or more corresponding receptors of cell adhesion molecules (not shown) presented on each target cell 12. The presence of a heavier density of exposed corresponding receptors in an arterial wall lesion 22 results in effective clustering of the ARCs 16 leading to the highlighting of said lesion 22. The dyeing effect of the targeted artery/arterial tree during both the short injection phase 24 and the longer subsequent illumination phase 26 is achieved via absorption or alternation of external electromagnetic radiation provided by the radiodense nucleus 20 of the proposed ARCs 16. On the macroscopic level, injection phase 24 shows the dyeing effect of intra-arterial injection of the proposed ARCs 16 in the corresponding drawing which depicts the left system of the epicardial coronaries. The dense-dyeing macroscopic injection phase 24 is followed by a prolonged phase of fainter macroscopic illumination 26 which shows the fainter dyeing in the corresponding drawing which also depicts the left system of the epicardial coronaries.
[0071] FIG. 20 describes a basic method of preparation of the proposed multivalent adsorptive radiocontrast nanoconstructs (MARCs), wherein a radiodense nanocore undergoes a surface activation, which can be achieved in a preferred embodiment using 1-ethyl-3-(3-dimethylaminopropyl)-carbodiimide (EDC), to generate active esters that is less prone to hydrolysis, followed by in-water coupling with pluralities of adhesive peptides or peptidomimetics, which can be comprising the integrin-binding cell-adhesive domain of RGD tripeptides, to generate multivalent adsorptive radiocontrast nanoconstructs (MARCs) of diblock nanospheres and/or diblock nanoparticles (according to the shape of pre-activation radiodense nanocore). In another embodiment, after surface activation, the step of in-water coupling occurs with a liker, which can be a PEG chain, then said linker is activated to react with pluralities of adhesive peptides or peptidomimetics, which can be comprising the integrin-binding cell-adhesive domain of RGD tripeptides, to generate multivalent adsorptive radiocontrast nanoconstructs (MARCs) of triblock nanospheres and/or triblock nanoparticles. In an additional embodiment, the linker PEG chains can be separately activated and react with: (I) pluralities of adhesive peptides/peptidomimetic, which can be comprising the integrin-binding cell-adhesive domain of RGD tripeptides to form pegylated pluralities of adhesive peptides/peptidomimetic, and (II) one or more additional therapeutically active molecule, herein the vasodilator nitrate esters, to form a pegylated therapeutically active molecule. Then, these pegylated molecules react, in an in-water coupling step, with the already-activated surface of radiodense nanocores to generate multivalent adsorptive radiocontrast nanoconstructs (MARCs) of triblock nanospheres and/or triblock nanoparticles.
[0072] FIG. 21a depicts a schematic description showing the diblock structure of the proposed MARCs. The structure of MARCs of diblock nanospheres 28 and nanoparticles 30 comprises a spherical/non-spherical radiodense nanocore 32, which is capable of absorbing or altering external electromagnetic radiation resulting in decreased exposure on an electromagnetic waves detector, coated with a coat of pluralities adhesive peptides/peptidomimetics 34, whereby these pluralities of adhesive peptides/peptidomimetics 34 are presented to interact simultaneously with multiple corresponding binding sites. The advantages of this structure comprise the previously mentioned dual therapeutic and diagnostic actions.
[0073] FIG. 21b depicts a schematic description showing the triblock structure of the proposed MARCs. The structure of MARCs of triblock nanospheres 36 and nanoparticles 38 comprises a spherical/non-spherical radiodense nanocore 32, which is capable of absorbing or altering external electromagnetic radiation resulting in decreased exposure on an electromagnetic waves detector, coated with a subcoat of linkers 40, which can comprise a biodegradable layer of fluidic material above which a coat of pluralities adhesive peptides/peptidomimetics 34 can be incorporated, whereby these pluralities of adhesive peptides/peptidomimetics 34 are presented to interact simultaneously with multiple corresponding binding sites. Said structure increases the ability of dynamic repositioning of these bound pluralities of adhesive peptides/peptidomimetics 34. The advantages of this structure comprise the previously mentioned dual therapeutic and diagnostic actions. Besides, the proposed structure retains the molecular flexibility and spacing provided by the linker subcoat, so that decreasing the steric hindrance.
[0074] An additional advantage of the proposed structures is multivalency, wherein the structure helps simultaneous multiple binding interactions between the multiple ligands presented by said constructs with their target receptors. So, individual binding events increase the probability of other interactions occurring between the unbound ligands of said constructs and their corresponding binding sites; due to an increase in the local concentration of each binding ligand in proximity to the corresponding binding site. Individually, each binding interaction may be readily broken; however, when many simultaneous binding interactions are present, the transient unbinding of a single site does not allow the molecule to diffuse away, and the binding of that weak interaction is likely to be restored. Accordingly, the multivalency and/or the linker flexibility with their corresponding augmented functional affinity can compensate for the notable binding weakness of the interaction between isolated domains (herein, cell-adhesive domains), without their complete protein (tertiary) structure, and their corresponding receptors.
[0075] So, the multivalency of the proposed constructs results in a stable construct-cell adhesion by increasing the avidity of the ligand-receptor non-covalent binding. Additionally, different ligands can be presented simultaneously by said constructs, so they can be monospecific if the presented ligands are identical, or polyspecific if the presented ligands are non-identical. Besides, the proposed structure is more biomimetic and may be essential for achieving the desired action.
[0076] The biodegradable structure is advantageous, wherein proteolytic-cleavable bonds guarantee a controllable degradation of the constructs which can then release still-therapeutically active byproduct molecules, for example, the gradual constructs degradation and wash-up are accompanied by continuous release of therapeutically active antiplatelet adhesive peptides or peptidomimetics comprising αIIbβ3 integrin-binding cell-adhesive domains of RGD tripeptides/RGD-peptidomimetics. Also, the flexible composite structure can attain multiple therapeutic functions via conjugating one or more therapeutically active molecules. Besides, the flexibility provided by the linkers and/or the fluidic nature of the subcoat enables unrestricted mobility of the bound biomolecules facilitating focal adhesion, clustering, and redistribution, which help decrease the steric hindrance and increase the avidity due to increasing the availability of binding ligands to their corresponding receptors. Moreover, the proposed exemplary use of PEG linkers/subcoat increases solubility, decreases immunogenicity and antigenicity, shields the constructs from recognition by the reticuloendothelial system, and inhibits non-specific interaction and opsonization. Additionally, the degree of fluidity of the PEG subcoat can be controlled by monitoring the molecular weight of PEG molecules.
[0077] FIG. 22 depicts a schematic description of the basic mechanism of action of the proposed MARCs (herein, MARCs of diblock nanospheres 28 and nanoparticles 30 as well as MARCs of triblock nanospheres 36 and nanoparticles 38), wherein the interaction of said MARCs 28, 30, 36, and 38 with a target cell 12 of the inner arterial wall is shown at the microscopic level, combined with the corresponding result at the macroscopic level. Said target cell 12 presents surface receptors in the form of cell-adhesion molecules (not shown), preferentially integrins, and during the injection phase 24, the MARCs 28, 30, 36, and 38 are rushed through the bloodstream 14 due to elevated intra-arterial pressure (normally, 120 mmHg during systole). Then, a subsequent illumination phase 26 follows, wherein a considerable amount of the injected MARCs 28, 30, 36, and 38 interacts with the target cells 12 of the inner arterial wall leading to adsorptive/adhesive fixation. This fixation results from the simultaneous interaction between the coat of pluralities of adhesive peptides/peptidomimetics 34 of each MARC 28, 30, 36, and 38 with multiple corresponding receptors of cell adhesion molecules (not shown) presented on each target cell 12. The presence of a heavier density of exposed corresponding receptors in an arterial wall lesion 22 results in effective clustering of the MARCs 28, 30, 36, and 38 leading to the highlighting of said lesion 22. The dyeing effect of the targeted artery/arterial tree during both the short injection phase 24 and the longer subsequent illumination phase 26 is achieved via absorption or alternation of external electromagnetic radiation provided by the radiodense nanocore 32 of the proposed MARCs 28, 30, 36, and 38. On the macroscopic level, the injection phase 24 shows the dyeing effect of intra-arterial injection of the proposed MARCs 28, 30, 36, and 38, via a suitable catheter 42, in the corresponding drawing which depicts the left system of the epicardial coronaries. The dense-dyeing macroscopic injection phase 24 is followed by a prolonged phase of fainter macroscopic illumination 26 which shows the fainter dyeing in the corresponding drawing which also depicts the left system of the epicardial coronaries. The figure also shows a method of using the invention to help a recipient in need thereof, wherein a real-time continuous visualization of an artery can be obtained via intra-arterial direct injection of the proposed constructs using a suitable catheter 42. Accordingly, the present invention is advantageous when used for procedural real-time angiography with or without percutaneous intervention.
DRAWINGS REFERENCE NUMBER
[0078]
TABLE-US-00001 12 Target cell 14 Bloodstream 16 Adsorptive radiocontrast 18 Adhesive arm construct (ARC) 20 Radiodense nucleus 22 Lesion 24 Injection phase 26 Illumination phase 28 Multivalent adsorptive 30 Multivalent adsorptive radiocontrast nanoconstruct radiocontrast nanoconstruct (MARC) of diblock nano- (MARC) of diblock nano- spheres particles 32 Radiodense nanocore 34 Coat of pluralities of adhesive peptides/peptidomimetic 36 Multivalent adsorptive 38 Multivalent adsorptive radiocontrast nanoconstruct radiocontrast nanoconstruct (MARC) of triblock nano- (MARC) of triblock nano- spheres particles 40 Subcoat of linkers 42 Suitable catheter
REFERENCES
[0079] Agthoven, Johannes F Van, Jian-Ping Xiong, Jose Luis Alonso, Xianliang Rui, Brian D Adair, Simon L Goodman, and M Amin Arnaout. 2014. “Structural Basis for Pure Antagonism of Integrin α V β3 by a High-Affinity Form of Fibronectin.” Nature Structural & Molecular Biology 21 (4): 383-88. [0080] Alon, Ronen, Edward A Bayer, and Meir Wilchek. 1990. “Streptavidin Contains an RYD Sequence Which Mimics the RGD Receptor Domain of Fibronectin.” Biochemical and Biophysical Research Communications 170 (3): 1236-41. [0081] Bae, Kyongtae T. 2010. “Intravenous Contrast Medium Administration and Scan Timing at CT: Considerations and Approaches.” Radiology 256 (1): 32-61.
[0082] Boateng, Samuel Y, Syed S Lateef, William Mosley, Thomas J Hartman, Luke Hanley, and Brenda Russell. 2005. “RGD and YIGSR Synthetic Peptides Facilitate Cellular Adhesion Identical to That of Laminin and Fibronectin but Alter the Physiology of Neonatal Cardiac Myocytes.” American Journal of Physiology-Cell Physiology 288 (1): C30-38. [0083] Calvete, Juan J. 1995. “On the Structure and Function of Platelet Integrin A11143, the Fibrinogen Receptor.” Proceedings of the Society for Experimental Biology and Medicine 208 (4): 346-60. [0084] Hynes, Richard O. 2002. “Integrins: Bidirectional, Allosteric Signaling Machines.” Cell 110 (6): 673-87. [0085] Ibanez, Borja, Stefan James, Stefan Agewall, Manuel J Antunes, Chiara Bucciarelli-Ducci, Hector Bueno, Alida L P Caforio, Filippo Crea, John A Goudevenos, and Sigrun Halvorsen. 2018. “2017 ESC Guidelines for the Management of Acute Myocardial Infarction in Patients Presenting with ST-Segment Elevation: The Task Force for the Management of Acute Myocardial Infarction in Patients Presenting with ST-Segment Elevation of the European Socie.” European Heart Journal 39 (2): 119-77. [0086] Knight, C Graham, Laurence F Morton, Anthony R Peachey, Danny S Tuckwell, Richard W Farndale, and Michael J Barnes. 2000. “The Collagen-Binding A-Domains of Integrins A1β1 and A2β1recognize the Same Specific Amino Acid Sequence, GFOGER, in Native (Triple-Helical) Collagens.” Journal of Biological Chemistry 275 (1): 35-40. [0087] Li, Feiya, Sambra D Redick, Harold P Erickson, and Vincent T Moy. 2003. “Force Measurements of the A5β1 Integrin—Fibronectin Interaction.” Biophysical Journal 84 (2): 1252-62.
[0088] McLane, Mary A, Elda E Sanchez, Alice Wong, Carrie Paquette-Straub, and John C Perez. 2004. “Disintegrins.” Current Drug Targets-Cardiovascular & Hematological Disorders 4 (4): 327-55. [0089] Mould, A Paul, Stephanie J Barton, Janet A Askari, Susan E Craig, and Martin J Humphries. 2003. “Role of ADMIDAS Cation-Binding Site in Ligand Recognition by Integrin A5β1.” Journal of Biological Chemistry 278 (51): 51622-29. [0090] Ruoslahti, Erkki. 1988. “Fibronectin and Its Receptors.” Annual Review of Biochemistry 57 (1): 375-413. [0091] Sorenson, James A, and Michael E Phelps. 1987. Physics in Nuclear Medicine. Grune & Stratton New York.
[0092] Xiong, Jian-Ping, Thilo Stehle, Rongguang Zhang, Andrzej Joachimiak, Matthias Frech, Simon L Goodman, and M Amin Arnaout. 2002. “Crystal Structure of the Extracellular Segment of Integrin AVβ3 in Complex with an Arg-Gly-Asp Ligand.” Science 296 (5565): 151-55. [0093] Zhu, Yunxiao, Zdravka Cankova, Marta Iwanaszko, Sheridan Lichtor, Milan Mrksich, and Guillermo A Ameer. 2018. “Potent Laminin-Inspired Antioxidant Regenerative Dressing Accelerates Wound Healing in Diabetes.” Proceedings of the National Academy of Sciences 115 (26): 6816-21.
CONCLUSION
[0094] The proposed ARCs/MARCs are designed to have dual therapeutic and diagnostic actions which enhance the efficacy of real-time arterial dyeing during procedural angiography with or without percutaneous interventions. While the above description contains many specificities, these should not be construed as limitations on the scope of the invention, but rather as an exemplification of preferred embodiments thereof. Many other variations are possible. Accordingly, the scope of the invention should be determined not by the embodiments illustrated, but by the appended claims and their legal equivalents.
