Nanoscale chemical imaging of individual chemotherapeutic cytarabine-loaded liposomal nanocarriers

Published

January 1, 2019

Author(s)

Wieland Karin, Georg Ramer, Victor U. Weiss, Guenter Allmaier, Bernhard Lendl, Andrea Centrone

Abstract

Dosage of chemotherapeutic drugs is a tradeoff between efficacy and side-effects. Liposomes are nanocarriers that increase therapy efficacy and minimize side-effects by delivering otherwise difficult to administer therapeutics with improved efficiency and selectivity. Still, variabilities in liposome preparation require assessing drug encapsulation efficiency at the single liposome level, an information that, for non-fluorescent therapeutic cargos, in inaccessible due to the minute drug load per liposome. Photothermal induced resonance (PTIR) provides nanoscale compositional specificity, up to now, by leveraging an atomic force microscope (AFM) tip contacting the sample to transduce the sample's photothermal expansion. However, on soft samples (i.e. liposomes) PTIR effectiveness is reduced due to the likelihood of tip-induced sample damage and inefficient AFM transduction. Here, individual liposomes loaded with the chemotherapeutic drug cytarabine are deposited intact from suspension via nES- GEMMA (nano-electrospray gas-phase electrophoretic mobility molecular analysis) collection and characterized at the nanoscale with the chemically-sensitive PTIR method. A new tapping-mode PTIR imaging paradigm based on heterodyne detection is shown to be better adapted to measure soft samples, yielding cytarabine distribution in individual liposomes and enabling classification of empty and drug-loaded liposomes. The measurements highlight PTIR capability to detect ≈ 10³ cytarabine molecules (≈ 1.7 zmol) label-free and non-destructively.

Citation

Nano Research

Volume

12

Issue

1

Pub Type

Journals

Download Paper

https://doi.org/10.1007/s12274-018-2202-x

Local Download

Keywords

PTIR, liposomes, nanoscale chemical imaging

Citation

Karin, W. , Ramer, G. , Weiss, V. , Allmaier, G. , Lendl, B. and Centrone, A. (2019), Nanoscale chemical imaging of individual chemotherapeutic cytarabine-loaded liposomal nanocarriers, Nano Research, [online], https://doi.org/10.1007/s12274-018-2202-x, https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=925919 (Accessed October 14, 2025)