Development of Excipient-Free Freeze-Dryable Unimolecular Hyperstar Polymers for Efficient siRNA Silencing.

We designed a unimolecular hyperstar polymer for efficient small interfering RNA (siRNA) delivery that can be processed under repeated lyophilization and reconstitution without the need of any excipient. The hyperstar polymer contains a biodegradable hyperbranched core and is bound to siRNA through its thousands of cationic arms that radiate from its core. The siRNA/hyperstar complexes showed siRNA transfection efficiency that was superior to that of Lipofectamine2000 in regard to the gene for human Cu, Zn superoxide dismutase 1 (SOD1), whose mutation causes familial amyotrophic lateral sclerosis.

Tailoring dye-sensitized upconversion nanoparticle excitation bands towards excitation wavelength selective imaging.

One of the key roadblocks in UCNP development is its extremely limited choices of excitation wavelengths. We report a generic design to program UCNPs to possess highly tunable dye characteristic excitation bands. Using such distinctive properties, we were able to develop a new excitation wavelength selective security imaging.

Amplifying the red-emission of upconverting nanoparticles for biocompatible clinically used prodrug-induced photodynamic therapy.

A class of biocompatible upconverting nanoparticles (UCNPs) with largely amplified red-emissions was developed. The optimal UCNP shows a high absolute upconversion quantum yield of 3.2% in red-emission, which is 15-fold stronger than the known optimal β-phase core/shell UCNPs.