Characterization of a drug delivery system for the antifungal peptide MUC7 12-mer using time-of-flight secondary ion mass spectrometry (TOF-SIMS) and X-ray photoelectron spectroscopy (XPS)

PMSE 259

Jennifer A. Appawu, appawu@buffalo.edu1, Jinxiang Yu1, Joseph A. Gardella, gardella@acsu.buffalo.edu2, G. Wei3, and Libuse A. Bobek3. (1) Department of Chemistry, SUNY at Buffalo, 476 Natural Science Complex, Buffalo, NY 14260, (2) Department of Chemistry/Analytical Chemistry, State University of New York (SUNY) at Buffalo, Natural Science Complex, Buffalo, NY 14260-3000, (3) Department of Oral Biology, SUNY at Buffalo, Buffalo, NY 14214
Hydrogel polymers have been used in localized delivery of drugs/proteins to wounded areas for controlled release and efficiency. Hydrogels are cross-linked polymers that can swell with water or other biological fluids through pores defined by the type and density of cross links. Uptake and release can be diffusion controlled. Key questions in their use are: what concentration of the drug is needed for constant drug release and can the amount of drug released on the surface of a hydrogel be quantified? XPS and TOF-SIMS are two techniques that are used to analyze the surface of hydrogels imbibed with synthesized peptide MUC7 12-mer (human salivary low-molecular-mass mucin) (1). XPS is used to study the chemical composition of polymer surfaces at various depths by varying the take-off-angle (TOA). The concentration of MUC7 12-mer peptide contained within the hydrogel can be monitored by measuring the nitrogen atomic concentration since nitrogen is only present within the 12mer peptide. Information collected from the XPS experiments will help guide the next step of analysis with the TOF-SIMS. A new TOF-SIMS method (2) will also allow depth profiling to be conducted to determine the in depth compositional profile of the drug within the polymer matrix. Data collected from both methods will be used to develop a fast method to determine that amount of the peptide on the surface and if this amount is enough to contribute to efficient wound healing.