Surface Modification of PLGA Particles: The Interplay between Stabilizer, Ligand Size, and Hydrophobic Interactions

Gerda Ratzinger-Stöger, Ursula Länger, Lukas Neutsch, Fritz Pittner, Michael Wirth, Franz Gabor (Corresponding author)

Publications: Contribution to journalArticlePeer Reviewed

Abstract

Therapeutic and diagnostic carriers call be functionalized with active targeters to induce tissue-specific delivery. However, the possible impact of adsorbed steric stabilizer such as the frequently used poloxamers (Pluronics) on surface modification of poly(D,L-lactide-co-glycolide) (PLGA) particles has not been examined so Far. Therefore, three model ligands of different molecular weights (653; 36 000: 155 000 g/mol) covering the size range of important targeters were conjugated to the surface of PLGA microparticles in the presence of different concentrations of Pluronic F68 (0.01-5%, w/v). Flow cytometry and fluorimetric quantification revealed for all tested ligands that high Pluronic concentrations decreased the coupling efficiency to a half or even one-third of that achieved in the absence of stabilizer. Moreover, the reduction strongly depends on the ligand size and its propensity for hydrophobic interactions. Apart front that, a high degree of particle aggregation was observed with Pluronic concentrations below 0.1% (w/v). Thus, a compromise has to be found, which combines sufficient stability with the best possible ligand coupling efficiency. For the studied system, 0.1% (w/v) turned out to be the optimum concentration of Pluronic F68.
Original languageEnglish
Pages (from-to)1855-1859
Number of pages5
JournalLangmuir: the A C S journal of surfaces and colloids
Volume26
Issue number3
DOIs
Publication statusPublished - 2010

Austrian Fields of Science 2012

  • 3012 Pharmacy, Pharmacology, Toxicology

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