Light-assisted drying for protein stabilization.

A light-based processing method to create an amorphous trehalose matrix for the stabilization of proteins is discussed. This method has potential applications in the stabilization of protein-based therapeutics and diagnostics. During light-assisted drying (LAD), proteins suspended in a trehalose solution are dehydrated using near-infrared (NIR) laser light. The goal of this study was to determine processing parameters that resulted in fast processing times and low end moisture contents (EMC), while maintaining the functionality of embedded proteins. We compared the effect of changing processing wavelength, power and resulting sample temperature, and substrate material on the EMC for two NIR laser sources (1064 and 1850 nm). The 1850-nm laser resulted in the lowest EMC (0.03  ±  0.01  gH2O  /  gDryWeight) after 20 min of processing on glass microfiber paper. This suggests a storage temperature of 68.3°C. We also tested the functionality of a model protein, lysozyme, after LAD processing using a standard assay. LAD showed no significant effect on the functionality of lysozyme when processed at a maximum temperature of ∼44  °  C to an EMC of 0.17  ±  0.06  gH2O  /  gDryWeight. LAD is a promising technique for forming amorphous trehalose solids that could stabilize proteins at ambient temperatures.