Light-assisted drying (LAD): A new process for producing an amorphous trehalose preservation matrix for the storage of biologics

The requirement for temperature-controlled storage can be challenging and expensive for the transportation and storage of biologics. Light-assisted drying (LAD) is a new processing technique to prepare biologics for storage in a trehalose amorphous solid matrix at ambient temperatures. Samples are illuminated with near-infrared laser light to speed dehydration. Previous work has shown LAD can prepare small-volume (40 μL) samples, but the feasibility of applying LAD to larger samples remains unexplored. Here, LAD is applied to large-volume samples (250 μL). Samples of a trehalose solution with an embedded protein were LAD processed and stored for 1 month. The end moisture contents of samples were determined after processing and storage. Thermal histories were monitored to determine optimal drying times. The trehalose matrix was characterized using polarized light imaging and Raman spectroscopy. Karl-Fischer (KF) titration was used to measure the water content. The end moisture contents and thermal histories show high repeatability for LAD processing. Polarized light imaging demonstrates that the trehalose matrix was resistant to crystallization. Raman spectroscopy indicates uniform water distribution and KF titration reveals a low average water content (2.5%). LAD can stabilize large-volume samples for dry-state storage at ambient temperatures and offers a potential solution for cold-chain storage challenges.