Regensburg 2007 – wissenschaftliches Programm
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CPP: Fachverband Chemische Physik und Polymerphysik
CPP 22: POSTER: INTERNAL SYMPOSIUM Optical Spectrosopy
CPP 22.11: Poster
Mittwoch, 28. März 2007, 16:00–18:30, Poster B
Vibrational Sum Frequency Scattering on Biomedical Poly (lactic acid) Microspheres — •albert sugiharto1, claes magnus johnson1, marc smits2, johannes nijsen3, and sylvie roke1 — 1MPI for Metals Research, Stuttgart, Germany — 2FOM-Institute AMOLF, Amsterdam, The Netherlands — 3Departement of Nuclear Medicine, University Hospital, Utrecht, The Netherlands
Biodegradable poly(lactic acid)(PLA) microspheres have recently been applied as a medicine against liver cancer [1]. In this proposed treatment, one injects polymer particles loaded with radioactivated heavy metal (Ho) complex into hepatic artery. The particles are transported to the tumor site, and from there irradiate and destroy the tumor cells. To understand the interaction of these particles with the body, it is important to investigate the bulk and surface structure of these particles on a detailed molecular level.
We have probed the particle structure using vibrational sum frequency scattering [2], a novel technique that combines all the advantages of vibrational sum frequency generation (SFG) with light scattering. This means one can obtain information about both the bulk and the surface structure on the molecular level as well as particle shape and size.We find that the PLA microspheres consist of crystallite domains, in which two adjacent helical PLA chains are arranged anti-parallel to each other. Furthermore we observed crucial structural changes between microspheres with and without medicinal complex.
[1] J.F.W. Nijsen et al., Eur. J. Nucl. Med. 26, 699 (1999)
[2] S. Roke et al., Phys. Rev. Lett. 91, 258302 (2003)