Bioabbaubare funktionalisierte fluoreszierende und superparamagnetische Polymernanopartikel

Abstract

Hydrophobic iron oxide nanoparticles with 25 or 10 nm in diameter and the fluorescent dye PMI were successfully loaded into poly(L-lactide) using the combination of miniemulsion and solvent evaporation techniques. The obtained particles have an average diameter of 120 nm (with 25 nm iron oxide) or 130 to 180 nm (with 10 nm magnetite) and show high stability in the aqueous phase. The iron oxide particles show superparamagnetic behaviour. Cell experiments with mesenchymal stem cells show very good particle uptake and excellent cell viability. The ability of the MSCs to differentiate as well as the phenotype are not changed by the particle uptake. Labeled MSCs can be distinguished from the negative control and can be detected in vivo in MRI as well. The magnetic properties of the PLLA particles and the possibility to encapsulate hydrophobic molecules (e.g. dyes, drugs) into the polymer matrix predestine these particles for magnetically targeted drug delivery and as contrast agent for magnetic resonance imaging. Functionalized PLLA/P(MAA-co-St), PLLA/P(AEMH-co-St) or PLLA/P(PEG-co-St) composite particles can be synthesized using a combination of miniemulsion, free radical copolymerization and solvent evaporation techniques. Depending on the synthesis route of the copolymer, nanoparticles between 120 and 180 nm in diameter are received. The morphology of the obtained nanoparticles can be altered by the synthesis route or the monomer ratio between homogeneous, hemispherical or Janus-like. The amount of functional groups on the surface can be varied by the monomer ratio or the preparation technique. Magnetic and functionalized PLLA based composite particles can be analog synthesized. Iron oxide particles with 25 as well as 10 nm in diameter were encapsulated into the composite particles.