AVS 51st International Symposium
    Biomaterial Interfaces Wednesday Sessions
       Session BI-WeA

Paper BI-WeA8
Surface Segregation of Pluronic® P104 in Poly(@subL@-lactic acid) Characterized by XPS and ToF-SIMS

Wednesday, November 17, 2004, 4:20 pm, Room 210D

Session: "Passive" and Non-Fouling Surfaces
Presenter: J.-X. Yu, State University of New York at Buffalo
Authors: J.-X. Yu, State University of New York at Buffalo
C.M. Mahoney, National Institute of Standards and Technology
J. Gardella, State University of New York at Buffalo
Correspondent: Click to Email
This study reports results of the surface and in-depth characterization of two component blend films of poly(L-lactic acid) (PLLA) and Pluronic® surfactant [poly(ethylene oxide) (A) poly(propylene oxide) (B) ABA block copolymer]. The bulk properties of these polymers have been well studied by many groups due to their biomedical applications. Angle dependant X-ray photoelectron spectroscopy (XPS) and Time-of-flight secondary ion mass spectrometer (ToF-SIMS) depth profiling were used for monitoring the surfactant’s surface concentration at different sampling depths. We found a critical saturation concentration of the surfactant, a depletion region beneath the topmost surfactant enriched zone, and the existence of the surfactant’s segregation in the whole film with different intensities. We conclude that the surfactant’s surface segregation increases and then stays stable when increasing its bulk concentration. These results suggest that the selection of the surfactant bulk concentration of the thin film matrices for drugs/proteins delivery should achieve a relatively homogeneous distribution of stabilizer/protein in the PLLA matrix.