title: Low temperature thermal dependent Filgrastim adsorption behavior detected with ToF-SIMS.
abstract: Time-of-flight secondary ion mass spectrometry (ToF-SIMS) detected changes in Filgrastim (granulocyte colony stimulating growth factor, G-CSF) adsorption behavior at a solid interface when exposed to temperatures as low as 35 °C, i.e., before thermal denaturation, was detected by circular dichroism (CD) or dynamic light scattering (DLS). Biopharmaceuticals rely on maintaining sufficient conformation to impart correct biological function in vivo. Stability of such molecules is critical during synthesis, storage, transport, and administration. CD analysis indicated loss of structure at temperatures greater than ~60 °C, while DLS detected aggregation at ~42 °C. Furthermore, we demonstrate the nature of G-CSF interaction with a surface was altered rapidly and at relatively low temperatures. Specifically, after 10 min thermal treatment, changes in adsorption behavior occurred at 35 °C indicated by principal component analysis of spectra as primarily due to increasing yields of methionine fragments. This was likely to be due to either altering the preferential protein orientation upon adsorption or greater denaturation exposing the hydrophobic core. This investigation demonstrates the sensitivity of ToF-SIMS in studying biopharmaceutical adsorption and conformational change and can assist with studies into promoting their stability.
authors.affiliation: Ian Wark Research Institute, University of South Australia , Mawson Lakes, S.A. 5095, Australia.
authors.forename: Ivan M
authors.initials: IM
authors.lastname: Kempson
authors.forename: Patrick
authors.initials: P
authors.lastname: Chang
authors.forename: Kristen
authors.initials: K
authors.lastname: Bremmell
authors.forename: Clive A
authors.initials: CA
authors.lastname: Prestidge
mesh_terms: D000327:Adsorption; D002942:Circular Dichroism; D000069585:Filgrastim; D016179:Granulocyte Colony-Stimulating Factor / Q000737:chemistry*; D011994:Recombinant Proteins / Q000737:chemistry; D018629:Spectrometry, Mass, Secondary Ion; D013499:Surface Properties; D013696:Temperature
chemical_list: D011994:Recombinant Proteins; D016179:Granulocyte Colony-Stimulating Factor; D000069585:Filgrastim