Polycationic nanoparticles: (1) synthesis of a polylysine-MION conjugate and its application in labeling fibroblasts.

Nanoparticles are increasingly used to label cells to track them by imaging or to quantify them in vivo. However, normal cellular uptake mechanisms are inadequate to load cells with tracking label. We propose a simple method to coat nanoparticles, such as monocrystalline iron oxide nanoparticle (MION), with the transfection agent polylysine in order to facilitate rapid, uniform, and heavy labeling of fibroblasts.

Cell tracking using nanoparticles.

Tracking cells in regenerative medicine is becoming increasingly important for basic cell therapy science, for cell delivery optimization and for accurate biodistribution studies. This report describes nanoparticles that utilize stable-isotope metal labels for multiple detection technologies in preclinical studies. Cells labeled with nanoparticles can be imaged by electron microscopy, fluorescence, and magnetic resonance.

An approach to heterobifunctional poly(ethyleneglycol) bioconjugates.

A family of differentially substituted poly(ethyleneglycol) building blocks has been assembled from commercially available material. Their utility is demonstrated by formation of amino acid conjugates, image contrast agents, gold nanoparticles, and functional antibody conjugates. Application in the cellular trafficking of antitumoral agent conjugates is expected.