SYNTHETIC PLATELETS

• US 20080213369A1
• Filed: 09/07/2007
• Published: 09/04/2008
• Est. Priority Date: 09/07/2006
• Status: Abandoned Application

• Current Assignee: Maria I.C. Gyongyossy-Issa
• Original Assignee: Canadian Blood Services
• Inventors: Del Carpio Munoz, Carlos A., Constantinescu, Iren, Campbell, William, Gyongyossy-Issa, Maria I.C., Kizhakkedathu, Jayachandran N.
• Application Number:
  US11/851,718
• Publication Number:
  US 20080213369A1
• Time in Patent Office: Days
• US Class Current: 424/486
• CPC Class Codes: A61K 35/19 Platelets; Megacaryocytes
• CPC Class Codes: A61K 47/6911 the form being a liposome
• CPC Class Codes: A61K 9/1271 Non-conventional liposomes, e.g. PEGylated liposomes, liposomes coated with polymers liposome as conjugate A61K47/6911
• CPC Class Codes: A61K 9/1277 Processes for preparing; Proliposomes
• CPC Class Codes: A61P 43/00 Drugs for specific purposes, not provided for in groups A61P1/00-A61P41/00
• CPC Class Codes: A61P 7/02 Antithrombotic agents; Anticoagulants; Platelet aggregation inhibitors
• CPC Class Codes: A61P 7/04 Antihaemorrhagics; Procoagulants; Haemostatic agents; Antifibrinolytic agents
• CPC Class Codes: A61P 9/00 Drugs for disorders of the cardiovascular system

Abstract

A synthetic platelet substitute that interacts with platelets and the (sub)endothelium, comprising: (a) a carrier molecule comprising lipidic particles with a cross-linked surface mesh, the lipidic particles comprising: an inner lipidic particle of pharmaceutically acceptable particle-forming lipids; hydrophilic polymer chains linked to the surface of the lipidic particle, the hydrophilic polymer chains comprising a crosslinkable end group at free ends thereof; and cross-linker groups linking the end groups of the hydrophilic polymer chains to form the cross-linked surface mesh; and (b) at least one receptor molecule attached to the surface of the carrier molecule. The receptor molecule can be a peptide moiety specific for ligands involved in platelet function.

Claims

1. A method for preparing a synthetic platelet substitute comprising a receptor molecule and a carrier molecule, said method comprising:

a. preparing a carrier molecule comprising lipidic particles with a cross-linked surface mesh by

i. preparing lipidic particles comprising pharmaceutically acceptable lipids,

ii. binding hydrophilic polymer chains to the surface of the lipidic particles, and

iii. cross-linking the hydrophilic polymer chains to form the cross-linked surface mesh; and

b. attaching at least one receptor molecule to the surface of the carrier molecule, wherein the receptor molecule is a peptide selected from the group consisting of SEQ ID NO;

1, SEQ ID NO;

2, SEQ ID NO;

3, SEQ ID NO;

4, SEQ ID NO;

5, SEQ ID NO;

6, SEQ ID NO;

7, SEQ ID NO;

8, SEQ ID NO;

9, SEQ ID NO;

10, SEQ ID NO;

11, SEQ ID NO;

12, SEQ ID NO;

13, SEQ ID NO;

14, SEQ ID NO;

15, SEQ ID NO;

16, SEQ ID NO;

17, SEQ ID NO;

18, SEQ ID NO;

19, SEQ ID NO;

20, SEQ ID NO;

21, SEQ ID NO;

22, analogs thereof having 90% sequence identity, and modified peptides thereof having an insertion of a Cys residue and/or a spectrophotometrically traceable amino acid and/or a poly-Gly tag consisting of 1 to 5 Gly residues.

2. The method of claim 1 wherein the peptide is selected from the group consisting of SEQ ID NO:

1, SEQ ID NO;

2, SEQ ID NO;

3, SEQ ID NO;

4, SEQ ID NO;

5, SEQ ID NO;

6, SEQ ID NO;

7, SEQ ID NO;

8, SEQ ID NO;

9, SEQ ID NO;

10, SEQ ID NO;

1, SEQ ID NO;

12, SEQ ID NO;

13, SEQ ID NO;

14, SEQ ID NO;

15, SEQ ID NO;

16, SEQ ID NO;

17, SEQ ID NO;

18, SEQ ID NO;

19, SEQ ID NO;

20, SEQ ID) NO;

21, SEQ ID NO;

22 and further comprises a Cys-(Gly)₅ tag at the N- or C-terminus thereof.

3. The method of claim 1 wherein the peptide is synthesized using D-amino acids.

4. The method of claim 1 wherein the peptide is synthesized using L-amino acids.

5. The method of claim 1 wherein the at least one receptor molecule is attached by means of a covalent linkage to the carrier molecule.

6. The method of claim 1 wherein the at least one receptor molecule is attached to the carrier molecule by means of a conjugate addition reaction between an amine group of the receptor molecule and free acrylate ends of a hydrogel-coated carrier molecule.

7. The method of claim 1 wherein a plurality of receptor molecules are attached to the surface of the carrier molecule.

8. The method according to claim 1, wherein the lipidic particles in step (a) comprise liposomes, vesicles, micelles, or combinations thereof.

9. The method according to claim 8, wherein the lipidic particles in step (a) comprise liposomes, the liposomes being prepared using 1,2 dipalmitoyl-sn-gycero-3-phosphoethanolamine (DPPE), 1,2 dipalmitoyl-sn-gycero-3-phosphocholine (DPPC) and cholesterol (CHOL).

10. The method according to claim 9, wherein the liposomes are prepared in a formulation having a molar ratio of about 40:

30;

30, respectively, of 1,2 dipalmitoyl-sn-gycero-3-phosphoethanolamine, 1,2 dipalmitoyl-sn-gycero-3-phosphocholine, and cholesterol.

11. The method according to claim 1, wherein the hydrophilic polymer chains in step (b) are straight-chain non-toxic polymers comprising a crosslinkable end group.

12. The method according to claim 1, wherein the hydrophilic polymer chains in step (b) comprise polyethylene glycol with an acrylate end group.

13. The method according to claim 7, wherein the molecular weight of the polyethylene glycol is about 3400 mw.

14. The method according to claim 1, wherein the cross-linking in step (c) comprises cross-linking free ends of the hydrophilic polymer chains with a cross-linker.

15. The method according to claim 14, wherein the cross-linker comprises polyethylene glycol diacrylate.

16. The method according to claim 15, wherein the polyethylene glycol diacrylate comprises polyethylene glycol with a molecular weight ranging from about 700 to about 20,000.

17. The method according to claim 15, wherein the polyethylene glycol diacrylate comprises polyethylene glycol with a molecular weight of about 6000.

18. The method according to claim 15, wherein the cross-linking is conducted in the presence of ammonium persulfate under ultraviolet light.

19. The method according to claim 15, wherein the polyethylene glycol diacrylate is diacryl-PEG₇₀₀ at a concentration between about 15 mM and 25 mM or diacryl-PEG₆₀₀₀ at a concentration between about 0.5 mM and 5 mM.

20. A synthetic platelet substitute that interacts with platelets and the (sub)endothelium, comprising:

a. a carrier molecule comprising lipidic particles with a cross-linked surface mesh, the lipidic particles comprising;

an inner lipidic particle of pharmaceutically acceptable particle-forming lipids;

hydrophilic polymer chains linked to the surface of the lipidic particle, the hydrophilic polymer chains comprising a crosslinkable end group at free ends thereof; and

cross-linker groups linking the end groups of the hydrophilic polymer chains to form the cross-linked surface mesh; and

b. at least one receptor molecule attached to the surface of the carrier molecule, wherein the receptor molecule is a peptide selected from the group consisting of SEQ ID NO;

1, SEQ ID NO;

2, SEQ ID NO;

3, SEQ ID NO;

4, SEQ ID NO;

5, SEQ ID NO;

6, SEQ ID NO;

7, SEQ ID NO;

8, SEQ ID NO;

9, SEQ ID NO;

10, SEQ ID NO;

11, SEQ ID NO;

12, SEQ ID NO;

13, SEQ ID NO;

14, SEQ ID NO;

15, SEQ ID NO;

16, SEQ ID NO;

17, SEQ ID NO;

18, SEQ ID NO;

19, SEQ ID NO;

20, SEQ ID NO;

21, SEQ ID NO;

22, analogs thereof having 90% sequence identity, and modified peptides thereof having an insertion of a Cys residue and/or a spectrophotometrically traceable amino acid and/or a poly-Gly tag consisting of 1 to 5 Gly residues.

21. An antithrombotic composition that interacts with platelets and the (sub)endothelium, comprising:

a peptide selected from the group consisting of SEQ ID NO;

1, SEQ ID NO;

2, SEQ ID NO;

3, SEQ ID NO;

4, SEQ ID NO;

5, SEQ ID NO;

6, SEQ ID NO;

7, SEQ ID NO;

8, SEQ ID NO;

9, SEQ ID NO;

10, SEQ ID NO;

11, SEQ ID NO;

12, SEQ ID NO;

13, SEQ ID NO;

14, SEQ ID NO;

15, SEQ ID NO;

16, SEQ ID NO;

17, SEQ ID NO;

18, SEQ ID NO;

19, SEQ ID NO;

20, SEQ ID NO;

21, SEQ ID NO;

22, analogs thereof having 90% sequence identity, modified peptides thereof having an insertion of a Cys residue and/or a spectrophotometrically traceable amino acid and/or a poly-Gly tag consisting of 1 to 5 Gly residues, and combinations thereof