Targeting properties of peptide-modified radiolabeled liposomal nanoparticles

Radiolabeled PEGylated liposomal nanoparticles (NPs) open new possibilities for a variety of applications including diagnosis, drug delivery, targeted therapy, and monitoring treatment effects. Here we describe the characterization of liposomal NPs (liposomes and micelles) derivatized with the somatostatin analogue tyrosine-3-octreotide as a proof of concept for tumor targeting. NPs were radiolabeled with indium-111, and targeting properties were evaluated in vitro on rat pancreatic tumor cells (AR42J), demonstrating specific binding and IC50 values in the low nanomolar range. Biodistribution studies were performed in Lewis rats and compared to single-photon emission computed tomography images. Moderate tumor uptake was found in xenografted nude mice (<2.5% ID/g tissue) as compared to control. Micelles and liposomes revealed comparable pharmacokinetics and targeting properties. This study provides insight into tumor-targeting characteristics of peptide-derivatized liposomal NPs and can serve as a basis for further improvement of these constructs.From the Clinical EditorThe authors investigated tumor-targeting characteristics of peptide-derivatized liposomal NPs. Similar radiolabeled PEGylated liposomal NPs open new possibilities for a variety of applications including diagnosis, drug delivery, targeted therapy, and treatment monitoring.

Graphical AbstractLiposomal NP (liposomes, micelles) were functionalized with Tyrosine-3-octreotide (TOC) and radiolabelled with 111In. Tumour targeting properties were evaluated in vitro on rat pancreatic tumour cells (AR42J) demonstrating specific binding and IC50 values in the low nanomolar range. Moderate tumour uptake was found in xenografted nude mice as compared to control. This study provides insight in tumour targeting properties of peptide-derivatized liposomal NP and can serve as a basis for further improvement of these constructs.Figure optionsDownload high-quality image (197 K)Download as PowerPoint slide