research
cellulose nanocrystals
Cellulose nanocrystals are rod-like nanoparticles of cellulose, a natural polysaccharide and the most abundant polymer on earth. Cellulose nanocrystals are prepared by hydrolysis of a purified cellulose starting material, such as bleached wood pulp or cotton, with either sulfuric or hydrochloric acid. The acid primarily degrades the less ordered, more accessible regions in the cellulose starting material and leaves highly crystalline nanoscale fragments behind. In the case of wood-derived cellulose as starting material, the resulting cellulose nanocrystals are approximately 100-150 nm long and 3-5 nm wide. Cellulose nanocrystals are extremely rigid and have attracted considerable attention as reinforcing additive in thermoplastic and thermosetting polymer systems. Research at the Biobased Advanced Materials Laboratory at Virginia Tech focuses on alternative uses for cellulose nanocrystals.
targeted delivery of therapeutics
Since the first investigation of liposomes as drug carrier systems in chemotherapy in 1974, nanoscale carrier systems have attracted increasing attention in therapeutic and diagnostic medicine. In search of the "magic bullet", many different types of nanoscale systems have been under evaluation, including metal, inorganic, and polymer nanoparticles, quantum dots, carbon nanotubes, polymer micelles, dendrimers, and liposomes. To achieve the desired benefits, nanoscale carrier systems have to be non-toxic, biodegradable, able to overcome the physiological barriers in the body, and able to withstand the immune system long enough to carry out their mission. Neither of the currently studied systems is optimal. Frequently encountered problems include toxicity, toxic degradation products, low stability in the bloodstream, and accumulation over time in certain organs such as the kidneys, liver, or spleen. An ongoing research collaboration between the Biobased Advanced Materials Laboratory and the Laboratory of Vascular Biology at the School of Biomedical Engineering and Sciences currently investigates applications of cellulose nanocrystals in nanobiomedicine.
