Modification of ligands for serum albumin on polyethyleneimine to stabilize polyplexes in gene delivery

<p>In this work, we have developed a new technique to stabilize a ternary complex composed of plasmid DNA, a linear polyethyleneimine (LPEI) and serum albumin. A stearoyl group was conjugated to LPEI as a specific ligand for serum albumin. The resultant ternary complex has excellent stability in physiological saline conditions, maintaining its initial diameter and preventing aggregation of red blood cells. The ternary complex has equivalent transfection ability to and significantly lower cytotoxicity than unmodified LPEI. Therefore, the ternary complex is potentially useful as a new gene carrier, possessing high blood stability.</p

Alkaline Phosphatase-Catalyzed Amplification of a Fluorescence Signal for Flow Cytometry

Despite the expanding use of flow cytometry, its detection limit is not satisfactory for many antigen proteins with low copy numbers. Herein, we describe an alkaline phosphatase (AP)-based technique to amplify the fluorescence signal for cell staining applications. We designed a fluorescent substrate that acquires membrane permeability upon dephosphorylation by AP. By using the substrate, the fluorescence signal of cells in flow cytometry could be successfully amplified to give a much stronger signal than the cells labeled using a conventional fluorophore-modified antibody