Nanoparticle Attachment to Erythrocyte Via the Glycophorin A Targeted ERY1 Ligand Enhances Binding without Impacting Cellular Function.

PURPOSE: Nanoparticle (NP) attachment to biocompatible secondary carriers such as red blood cell (RBC) can prolong blood residence time of drug molecules and help create next-generation nanotherapeutics. However, little is known about the impact of RBC-targeted NPs on erythrocyte function. METHODS: The objectives of this study were to develop and characterize in vitro a novel poly-L-lysine (PLL) and polyethylene glycol (PEG) copolymer-based NP containing fluorescent-tagged bovine serum albumin (BSA), and conjugated with ERY1, a 12 amino acid peptide with high affinity for the RBC membrane protein glycophorin A (ENP). RESULTS: Confocal and flow cytometry data suggest that ENPs efficiently and irreversibly bind to RBC, with approximately 70% of erythrocytes bound after 24 h in a physiologic flow loop model compared to 10% binding of NPs without ERY1. Under these conditions, synthesized ENPs were not toxic to the RBCs. The rheological parameters at the applied shear. (0-15 Pa) were not influenced by ENP attachment to the RBCs. However, at high concentration, the strong affinity of ENPs to the glycophorin-A reduced the deformability of the RBC. CONCLUSIONS: ENPs can be efficiently attached to the RBCs without adversely affecting cellular function, and this may potentially enhance circulatory half-life of drug molecules.

Optimized solvent-exchange synthesis method for C60 colloidal dispersions.

An existing solvent exchange method used to produce aqueous suspensions of fullerene C(60) aggregates (nC(60)) using the solvents toluene, tetrahydrofuran, acetone, and water, has been optimized for producing 75 nm diameter particles. Numerous synthesis parameters were evaluated for their effects on colloid yield and particle size distribution. Varying the relative volumes used of the intermediate solvents relative to the initial toluene volume allowed the controlled tuning of the resulting particle size up to a diameter of 210 nm. The resulting suspensions produced 10-20 ppm concentrations and reduced the residual organic solvents to less than the detection limit of 1 ppm.