This work presents the highly controlled drug delivery system free from the burst release at an initial stage and equipped with the capability of long term drug release. The nanoporous drug releasing reservoir was combined with porous body resembling cancellous bone. The materials were prepared by the integration of synthesized inorganic hydroxyapatite (HA) and the hybrid gels of bicontinuous sponge-phased L3 silicate and thermo-responsive poly(N-isopropylacrylamide) (L3-PNIPAm gels). The materials were designed to have the three dimensionally interconnected heterogeneous porosity of macro- and mesoporosity, in which the HA has the macroporosity of 150μm to be impregnated the drug into the pores and the L3-PNIPAm gels have mesoporosity of 5 nm to regulate the temperature sensitive drug-release through the pore channels and polymeric network, respectively. Consequently, this bone-mimetic system gave the highly long term drug release over the 60 days without the burst release. The release rate could be controlled with the change of the HA and PNIPAm composition ratios. The structural characterization was achieved by TEM, SEM, XRD, Micro-Raman spectroscopy, BET, and the direct contact cytotoxicity test was also described.

Date Published: 14 December 2006
PDF: 6 pages
Proc. SPIE 6416, Biomedical Applications of Micro- and Nanoengineering III, 641611 (14 December 2006); doi: 10.1117/12.695985

Published in SPIE Proceedings Vol. 6416:
Biomedical Applications of Micro- and Nanoengineering III
Dan V. Nicolau, Editor(s)