[Zurück]

K. Wieland, V. Weiss, G. Ramer, A. Centrone, G. Allmaier, B. Lendl:
"Nanoscale IR imaging of nES GEMMA size-selected liposomal drug delivery systems";
Vortrag: SpringSciX 2018, Technology and Innovation Centre, University of Strathclyde, Glasgow, Scotland; 17.04.2018 - 20.04.2018.

Due to their exceptional structural and functional versatility liposomes are widely used especially in clinical applications as drug delivery systems for cancer treatment. The encapsulation efficiency of anti-cancer drugs is of crucial importance to avoid overmedication. For non-fluorescent drugs, determination of the encapsulation efficiency usually requires a marker such as radioactive carbohydrates or fluorescent dyes. However, marker-based techniques are expensive, require careful handling due to the carcinogenicity of the majority of the available markers and they need careful adaptation of the staining protocol to the system under investigation. Additionally, they suffer from leakage, insufficient specificity and they also affect the biological system. Alternatively, encapsulation efficiencies can be averaged for vesicles during bulk measurements.
The photothermal induced resonance (PTIR), also known as AFM-IR, technqiue combines Infrared (IR) spectroscopy with Atomic Force Microscopy (AFM) and thus provides direct and label-free access to molecule-specific (i. e. drug) information at the nanoscale. Resonance enhanced PTIR provides an increased signal sensitivity leveraging a pulsed wavelength-tunable laser emitting light pulses at the frequency of the AFM contact resonance.
We propose a novel combination of nES GEMMA (nano-Electrospray Gas-phase Electrophoretic Mobility Molecular Analysis) and resonance enhanced PTIR for the investigation of drug encapsulation of single nanocarriers with well-defined particle size. nES GEMMA enables separation of nanoparticles according to their size and collection of these size-selected nanoparticles on flat surfaces for subsequent PTIR analysis. Here, we present our latest results investigating liposomes (85 nm in diameter) filled with a chemotherapeutic drug through PTIR imaging.

PTIR, AFM-IR, nES GEMMA, liposomes, drug delivery