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Targeted Drug Delivery Utilizing a Mini-Collagen Ligand Recognized by CD44/CSPG Melanoma Receptor

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Date Issued:
2007
Summary:
Liposomes of varying lipid compositions are currently used as drug carriers. and great efforts have been made to target these vehicles to specific cellular receptors. Previous targeting components include peptides. proteins. antibodies. or vitamins. CD44/CSPG is among the receptors overexpressed in metastatic melanoma. and the sequence to which it binds within the type IV collagen triple-helix has been identified. A triple-helical '·peptide-amphiphile .. (al(JV)1263-1277 PA) which binds CD44/CSPG has been constructed and incorporated into liposomes of differing lipid compositions. Liposomes containing distearoyl phosphatidylcholine (DSPC) as the major bilayer component. in combination with distearoyl phosphatidylglycerol (DSPG) and cholesterol. were more stable than analogous liposomes containing dipalmitoyl phosphatidylcholine (DPPC) instead of DSPC. The presence of the al(JV)1263-1277 PA conferred greater stability to the DPPC liposomal systems. and did not affect the stability of the DSPC liposomes. The addition of either PEG 750 or PEG 2000 (5 mol %) to DSPG/DSPC/Chol liposomes did not affect the stability of this system. Fluorophore delivery of rhodamine loaded liposomes to cells varymg 111 CD44/CSPG expresston was determined usmg fluorescence microscopy. The CD44/CSPG receptor content for two normal fibroblast cell lines, BJ and Hs895Sk, and a highly metastatic melanoma derived cell line, M 14#5. was determined using whole cell ELISA. The results of the ELISA showed varying levels of CD44 receptors amongst the cell lines. with M 14#5 cells having the most. A positive correlation was observed for cellular fluorophore delivery by the ai(IV)1263-1277 PA liposomes and CD44/CSPG receptor content. Conversely, non-targeted liposomes delivered minimal fluorophore to cells regardless of the CD44/CSPG receptor content. When cells were treated with exogeneous a I (IV) 1263-1277, prior to incubation with a I (IV) 1263 -1277 PA liposomes, a dose-dependent decrease in the amount of fluorophore delivered was observed with respect to increasing concentrations of exogeneous al(IV)1263-1277. In addition, we have found a positive correlation between the cytotoxic effect of ai(IV)l263-1277 PA targeted liposomes (with and without PEG) loaded with doxorubicin and the CD44/CSPG content amongst the three different cell lines. This trend was not observed with non-targeted liposomes. These findings provide the possibility of a novel drug carrier system to be used in future clinical applications against metastatic melanoma.
Title: Targeted Drug Delivery Utilizing a Mini-Collagen Ligand Recognized by CD44/CSPG Melanoma Receptor.
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Name(s): Khan, David R.
Florida Atlantic University, Degree grantor
Fields, Gregg B., Thesis advisor
Charles E. Schmidt College of Science
Department of Chemistry and Biochemistry
Type of Resource: text
Genre: Electronic Thesis Or Dissertation
Date Created: 2007
Date Issued: 2007
Publisher: Florida Atlantic University
Place of Publication: Boca Raton, Fla.
Physical Form: application/pdf
Extent: 159 p.
Language(s): English
Summary: Liposomes of varying lipid compositions are currently used as drug carriers. and great efforts have been made to target these vehicles to specific cellular receptors. Previous targeting components include peptides. proteins. antibodies. or vitamins. CD44/CSPG is among the receptors overexpressed in metastatic melanoma. and the sequence to which it binds within the type IV collagen triple-helix has been identified. A triple-helical '·peptide-amphiphile .. (al(JV)1263-1277 PA) which binds CD44/CSPG has been constructed and incorporated into liposomes of differing lipid compositions. Liposomes containing distearoyl phosphatidylcholine (DSPC) as the major bilayer component. in combination with distearoyl phosphatidylglycerol (DSPG) and cholesterol. were more stable than analogous liposomes containing dipalmitoyl phosphatidylcholine (DPPC) instead of DSPC. The presence of the al(JV)1263-1277 PA conferred greater stability to the DPPC liposomal systems. and did not affect the stability of the DSPC liposomes. The addition of either PEG 750 or PEG 2000 (5 mol %) to DSPG/DSPC/Chol liposomes did not affect the stability of this system. Fluorophore delivery of rhodamine loaded liposomes to cells varymg 111 CD44/CSPG expresston was determined usmg fluorescence microscopy. The CD44/CSPG receptor content for two normal fibroblast cell lines, BJ and Hs895Sk, and a highly metastatic melanoma derived cell line, M 14#5. was determined using whole cell ELISA. The results of the ELISA showed varying levels of CD44 receptors amongst the cell lines. with M 14#5 cells having the most. A positive correlation was observed for cellular fluorophore delivery by the ai(IV)1263-1277 PA liposomes and CD44/CSPG receptor content. Conversely, non-targeted liposomes delivered minimal fluorophore to cells regardless of the CD44/CSPG receptor content. When cells were treated with exogeneous a I (IV) 1263-1277, prior to incubation with a I (IV) 1263 -1277 PA liposomes, a dose-dependent decrease in the amount of fluorophore delivered was observed with respect to increasing concentrations of exogeneous al(IV)1263-1277. In addition, we have found a positive correlation between the cytotoxic effect of ai(IV)l263-1277 PA targeted liposomes (with and without PEG) loaded with doxorubicin and the CD44/CSPG content amongst the three different cell lines. This trend was not observed with non-targeted liposomes. These findings provide the possibility of a novel drug carrier system to be used in future clinical applications against metastatic melanoma.
Identifier: FA00000866 (IID)
Degree granted: Dissertation (Ph.D.)--Florida Atlantic University, 2007.
Collection: FAU Electronic Theses and Dissertations Collection
Note(s): Includes bibliography.
Charles E. Schmidt College of Science
Subject(s): Tumor suppressor proteins
Antioncogenes
Drug targeting
Melanoma--Treatment
Held by: Florida Atlantic University Libraries
Persistent Link to This Record: http://purl.flvc.org/fau/fd/FA00000866
Sublocation: Digital Library
Use and Reproduction: Copyright © is held by the author with permission granted to Florida Atlantic University to digitize, archive and distribute this item for non-profit research and educational purposes. Any reuse of this item in excess of fair use or other copyright exemptions requires permission of the copyright holder.
Use and Reproduction: http://rightsstatements.org/vocab/InC/1.0/
Host Institution: FAU
Is Part of Series: Florida Atlantic University Digital Library Collections.