title: New self-assembling polyaspartylhydrazide copolymer micelles for anticancer drug delivery.
abstract: A new amphiphilic copolymer have been synthesized starting from the hydrosoluble polyaspartylhydrazide (PAHy) polymer, by grafting both hydrophilic PEG(2000) chains and hydrophobic palmitic acid (C(16)) moieties on polymer backbone, and the structure of obtained PAHy-PEG(2000)-C(16) copolymer have been characterized by 2D (1)H/(13)C NMR experiments. PAHy-PEG(2000)-C(16) copolymer showed the ability of self-assembling in aqueous media giving a core-shell structure and resulted potentially useful for encapsulating and dissolving hydrophobic drug. The formation of micellar core-shell structure has been investigated by 2D (1)H NMR NOESY experiments. The presence of cross-peaks for protons of C(16) and PAHy portions, indicated that the two domains are in close proximity forming micelle core. The critical aggregation concentration (CAC) values of PAHy-PEG(2000)-C(16) amphiphilic graft copolymer was determined in water by fluorescence technique, and it was demonstrated that PAHy-PEG(2000)-C(16) micelles are well suited to be micellar vehicle of highly hydrophobic molecules. Therefore, anticancer drug tamoxifen, used as a model hydrophobic molecule, was loaded into PAHy-PEG(2000)-C(16) micelles obtaining an increase of drug solubility of about 3000 times. Transmission electron microscopy (TEM) observations showed the spherical morphology of micelles formed by PAHy-PEG(2000)-C(16) copolymer with a mean diameter of about 30nm, as confirmed also by dynamic light scattering (DLS) studies. Finally, in vitro cell viability studies were carried out on human breast cancer cells (MCF-7) testing the pharmacological activity of tamoxifen-loaded PAHy-PEG(2000)-C(16) micelles, in comparison with free tamoxifen at different drug concentrations, demonstrating that tamoxifen-loaded PAHy-PEG(2000)-C(16) micelles exhibited a concentration-dependent cytotoxic activity.
authors.affiliation: Dipartimento di Chimica e Tecnologie Farmaceutiche, University of Palermo, via Archirafi 32, 90123 Palermo, Italy.
authors.forename: Mariano
authors.initials: M
authors.lastname: Licciardi
authors.forename: Gennara
authors.initials: G
authors.lastname: Cavallaro
authors.forename: Mauro
authors.initials: M
authors.lastname: Di Stefano
authors.forename: Giovanna
authors.initials: G
authors.lastname: Pitarresi
authors.forename: Calogero
authors.initials: C
authors.lastname: Fiorica
authors.forename: Gaetano
authors.initials: G
authors.lastname: Giammona
mesh_terms: D000970:Antineoplastic Agents / Q000737:chemistry* / Q000494:pharmacology; D001943:Breast Neoplasms / Q000473:pathology; D045744:Cell Line, Tumor; D002470:Cell Survival / Q000187:drug effects; D002626:Chemistry, Pharmaceutical; D004305:Dose-Response Relationship, Drug; D004337:Drug Carriers; D004339:Drug Compounding; D005260:Female; D005453:Fluorescence; D006801:Humans; D057927:Hydrophobic and Hydrophilic Interactions; D008027:Light; D009682:Magnetic Resonance Spectroscopy; D008823:Micelles; D046529:Microscopy, Electron, Transmission; D036103:Nanotechnology; D019308:Palmitic Acid / Q000737:chemistry*; D010316:Particle Size; D010455:Peptides / Q000737:chemistry*; D011092:Polyethylene Glycols / Q000737:chemistry*; D011108:Polymers; D012542:Scattering, Radiation; D013629:Tamoxifen / Q000737:chemistry* / Q000494:pharmacology; D013678:Technology, Pharmaceutical / Q000379:methods
chemical_list: D000970:Antineoplastic Agents; D004337:Drug Carriers; D008823:Micelles; D010455:Peptides; D011108:Polymers; C442699:poly(aspartylhydrazide); D013629:Tamoxifen; D019308:Palmitic Acid; D011092:Polyethylene Glycols