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High-pressure Protein
Refolding
We recently patented a novel technique involving the use of high hydrostatic pressure (~2000 bar) to recover native-state protein from aggregated states. This technology has led to the formation of a contract refolding company Barofold. Ongoing research in this area involves elucidation of the thermodynamic driving forces behind the high-pressure refolding phenomenon. Recent publications: Seefeldt, M.B., Y.S., Kim, et al. (2005). "High-pressure studies of aggregation of recombinant human interleukin-1 receptor antagonist: thermodynamics, kinetics, and application to accelerated formulation studies." Protein Science 14(9):2258-66. PubMed Link Seefeldt, M.B., J. Ouyang, et al. (2004). "High-pressure refolding of bikunin: efficacy and thermodynamics." Protein Science 13(10):2639-50. PubMed Link St John, R. J., J. F.Carpenter, et al. (1999). "High pressure fosters protein refolding from aggregates at high concentrations." Proceedings of the National Academy of Sciences of the United States of America 96(23): 13029-13033. PubMed Link Current students (expected degree, date):
Aqueous Protein Formulation & Stability Current research focuses on the formulation of commercial protein products, particularly therapeutic proteins. Techniques such as light scattering, spectroscopy (CD, UV-VIS, FTIR, fluorescence), analytical ultracentrifugation, and HPLC are used to identify protein degradation (aggregation, etc.) in various liquid protein formulations Recent publications: Gabrielson, J.P., T.W. Randolph, et al. (2007). "Sedimentation velocity analytical ultracentrifugation and SEDFIT/c(s): limits of quantitation for a monoclonal antibody system." Analytical Biochemistry 361(1):24-30. PubMed Link Gabrielson, J.P., M.L. Brader, et al. (2007). "Quantitation of aggregate levels in a recombinant humanized monoclonal antibody formulation by size-exclusion chromatography, asymmetrical flow field flow fractionation, and sedimentation velocity." Journal of Pharmaceutical Sciences 96(2):268-79. PubMed Link Stoner, M.R., D.A. Dale, et al. (2006). "Surfactant-induced unfolding of cellulase: kinetic studies." Biotechnology Practice 22(1):225-32. PubMed Link Chi, E.Y., B.S. Kendrick, et al. (2005). "Population balance modeling of aggregation kinetics of recombinant human interleukin-1 receptor antagonist." Journal of Pharmaceutical Sciences 94(12):2735-48. PubMed Link Chi, E.Y., J. Weickmann, et al. (2005). "Heterogeneous nucleation-controlled particulate formation of recombinant human platelet-activating factor acetylhydrolase in pharmaceutical formulation." Journal of Pharmaceutical Sciences 94(2):256-74. PubMed Link Stoner, M.R., D.A. Dale, et al. (2004). "Ca2+-surfactant interactions affect enzyme stability in detergent solutions." Biotechnology Practice 21(6):1716-23. PubMed Link Stoner, M.R., N. Fischer, et al. (2004). "Protein-solute interactions affect the outcome of ultrafiltration/diafiltration operations." Journal of Pharmaceutical Sciences 93(9):2332-42. PubMed Link Chi, E.Y., S. Krishnan, et al. (2003). "Physical stability of proteins in aqueous solution: mechanism and driving forces in nonnative protein aggregation." Pharmaceutical Research 20(9):1325-36. PubMed Link Chi, E.Y., S. Krishnan, et al. (2003). "Roles of conformational stability and colloidal stability in the aggregation of recombinant human granulocyte colony-stimulating factor." Protein Science 12(5):903-13. PubMed Link Current Post-doc (dates):
Current students (expected degree, date):
Lyophilized Protein Formulation & Stability Lyophilization is a favorable alternative to aqueous formulation if the protein remains stable during the process. We are investigating the effects of excipients and processing parameters on formulation stability. Recent publications: Webb, S.D., J.L. Cleland, et al. (2003). "Effects of annealing lyophilized and spray-lyophilized formulations of recombinant human interferon-gamma." Journal of Pharmaceutical Sciences 92(4):715-29. PubMed Link Webb, S.D., S.L. Golledge, et al. (2002). "Surface adsorption of recombinant human interferon-gamma in lyophilized and spray-lyophilized formulations." Journal of Pharmaceutical Sciences 91(6):1474-87. PubMed Link Webb, S.D., J.L. Cleland, et al. (2002). "A new mechanism for decreasing aggregation of recombinant human interferon-gamma by a surfactant: slowed dissolution of lyophilized formulations in a solution containing 0.03% polysorbate 20." Journal of Pharmaceutical Sciences 91(2):543-58. PubMed Link Current student (expected degree, date):
Nanoparticle Science This area of research concerns the production and characterization of nanoparticles, primarily for pharmaceutical applications. We specialize in the precipitation with compressed antisolvent (PCA) process, and have recently developed a proprietary "jet-swirl" nozzle. Recent publications: Jarmer, D. J., C. S. Lengsfeld, et al. (2005). "Supercritical fluid crystallization of griseofulvin: crystal habit modification with a selective growth inhibitor." Journal of Pharmaceutical Sciences 94(12):2688-702. PubMed Link Jarmer, D. J., C. S. Lengsfeld, et al. (2004). " Nucleation and growth rates of poly(L-lactic acid) microparticles during precipitation with a compressed-fluid antisolvent." Langmuir 20(17):7254-64. PubMed LinkJarmer, D. J., C. S. Lengsfeld, et al. (2003). "Manipulation of particle size distribution of poly(L-lactic acid) nanoparticles with a jet-swirl nozzle during precipitation with a compressed antisolvent." Journal of Supercritical Fluids 27(3): 317-336. |