| Budget Amount *help |
¥3,900,000 (Direct Cost: ¥3,600,000、Indirect Cost: ¥300,000)
Fiscal Year 2007: ¥1,300,000 (Direct Cost: ¥1,000,000、Indirect Cost: ¥300,000)
Fiscal Year 2006: ¥2,600,000 (Direct Cost: ¥2,600,000)
|
|---|
| Research Abstract |
Drug delivery system (DDS) with an ability to deliver anti-tumor drugs to the diseased parts by localized, continuous way plays a key role for solving many kinds of problems on the present cancer therapy. The purpose of this study is to fabricate the medical device that can release loaded drugs through degradation and fast autonomous response toward external stimuli, to monitor the drug release fro this device by non-destructive, real-time optical way, and finally to establish implantable DDS with this device. Firstly, porous photonic device with inverse opal structure was fabricated using biodegradable, stimuli-responsive polymer gel. Secondly, non-destructive, real time optical measurement of the drug release of this device was performed with near infrared light.
The porous hydrogel was synthesized by polycondensation of citric acid and polyols at elevated temperature and characterized by XRD, IR absorption, Raman scattering, DSC, TG/MS and refractometry. As this result, the porous hy
… More
drogel was revealed to have 3D cross-linked structure with ester bonds and contain some amount of water molecules in this structure. From SEM observation, periodic macroporous structure, so-called inverse opal structure, was confirmed. Also, intense visible-MR reflection was observed in the reflection spectrum measured by fiber optics spectroscopy system combined with optical microscope. This optical reflection was theoretically supported by the Snell-Bragg equation and photonic band calculation. In addition, this material showed pH-dependent reflection.
Effects of in vitro and in vivo degradation on the periodic porous structure and optical reflection property of the porous hydrogel was examined. It was revealed that the 3D periodic structure was deformed and completely destructed by in vitro and in vivo degradation. Simultaneously, the optical reflection was continuously or discontinuously changed through the degradation with respect to the reflection intensity, reflection wavelength and peak width. These results suggest a possibility to monitor the degradation of this material by optical reflection. Also, biocompatibility of the porous hydrogel was confirmed by in vivo experiment. Moreover, model experiments for optical measurement for the porous hydrogel implanted in the subcutaneous tissue and drug release performance were preliminarily performed and relationship between amount of released drugs and optical reflectivity was examined.
In summary, we have successfully fabricated biodegradable, pH-responsive photonic device and opened up its application into implantable DDS, performance of which can be monitored through non-destructive, real-time optical way. Less
|
