Design and functionalization strategies for multifunctional nanocarriers (e.g., nanoparticles, micelles, polymersomes) based on biodegradable/biocompatible polymers intended to be employed for active targeting and drug delivery are reviewed. This review will focus on the nature of the polymers involved in the preparation of targeted nanocarriers, the synthesis methods to achieve the desired macromolecular architecture, the selected coupling strategy, the choice of the homing molecules (vitamins, hormones, peptides, proteins, etc.), as well as the various strategies to display them at the surface of nanocarriers. The resulting morphologies and the main colloidal features will be given as well as an overview of the biological activities, with a special focus on the main in vivo achievements.

Homogeneous coating of carbon nanotubes with metallic nanoparticles was achieved using supramolecular auto-organization of amphiphilic molecules as template. The resulting Pd nanoparticles/carbon nanotube nanohybrids were then evaluated in electrocatalysis experiments, showing superior activity in ethanol oxidation compared to analogous systems.

This concept article summarizes our recent findings regarding photopolymerized micelles obtained from the self-assembly of diacetylene-containing amphiphiles. Their synthesis and characterization are presented as well as some biomedical applications, such as tumor imaging and drug delivery. Finally, ongoing studies and future challenges are briefly discussed.

In vivo tumor targeting and drug delivery properties of small polymerized polydiacetylene (PDA) micelles (∼10 nm) is investigated in a murine MDA-MB-231 xenograft model of breast cancer. Three micelles with different surface coatings are synthesized and tested for their ability to passively target tumor through the enhanced permeability and retention effect. After injection (24 h), fluorescence diffuse optical tomographic imaging indicates a tumor uptake of nearly 3% of the injected dose for the micelles with a 2 kDa poly(ethylene glycol) (PEG)-coating (PDA-PEG2000). The uptake of PDA micelles in tumors is confirmed by co-localization with [(18) F]-fluorodeoxyglucose (FDG) positron emission tomography. Although FDG has a higher diffusion rate in tumors, 40 ± 19% of the retained micelles is co-registered with the tumor volume visualized by FDG. Finally, PDA-PEG2000 micelles are loaded with the hydrophobic anticancer drug paclitaxel and used in vivo to inhibit tumor growth. These findings demonstrate the potential of PDA-PEG2000 micelles for both in vivo tumor imaging and drug delivery applications.

Multifunctional poly­(ethylene glycol)-block-poly­(lactic acid) (PEG-b-PLA) nanoparticles for cancer cell targeting and imaging have been designed by a combination of ring-opening polymerization and “click” chemistry. Nanoparticles containing both a targeting ligand and a fluorescent probe were prepared by blending PLA-b-PEG–ligand, PLA-b-PEG–fluorescent probe, and PLA-b-PEG–OMe copolymers at the molar ratios necessary to achieve the desired surface ligand and fluorescent probe densities. This strategy has been illustrated by the preparation of a large library of a variety of nanoparticles, such as ligand-decorated nanoparticles (with biotin, folic acid or anisamide), fluorescent nanoparticles (UV–vis or near-infrared dyes), and multifunctional nanoparticles decorated with a targeting ligand and a fluorescent probe. Successful targeting was demonstrated by surface plasmon resonance and in vitro experiments on different cancer cell lines.

No abstract

The performance of small animal photonic imaging has been considerably improved since the development of fluorescence diffuse optical tomography (fDOT), which can reconstruct fluorescent probe distribution inside tissue. However, the quantification capabilities of this new technology are still a topic of debate, especially in comparison to classical nuclear imaging techniques. Here, we present a method to in vivo calibrate the quantity and localization of a probe provided by free-space fDOT (where no plate is compressing the mouse) with positron emission tomography (PET) and x-ray computed tomography, respectively. This methodology allowed us to demonstrate a strong linear correlation (R(2)=0.95) between fDOT and PET for probe concentrations ranging from 3 nM to 1 μM in a deep-seated organ.

No abstract