1997 Fiscal Year Final Research Report Summary
Endogenous signal-responsive drug release from bioactive bone cement
| Project/Area Number |
08680946
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Biomedical engineering/Biological material science
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| Research Institution | Kobe Pharmaceutical Univesity |
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Principal Investigator |
OTSUKA Makoto Kobe Pharmaceutical University, Associate Professor, 薬学部, 助教授 (90160548)
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| Co-Investigator(Kenkyū-buntansha) |
SUGIYAMA Yuichi University of Tokyo, Professor, 薬学部, 教授 (80090471)
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| Project Period (FY) |
1996 – 1997
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| Keywords | Osteoporosis / Drug delivery system / apatite / biomaterials / sustained drug release / atificial bone / intelligent materials / bone mineral density |
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| Research Abstract |
Osteoporotic fractures are observed more commonly among post-menopausal women, since bone mechanical strength is closely related to bone mineral density which reflects nutritional factors such as calcium and vitamin D.Since steroid hormones with estrogenic activity such as oestradiol and estron are considered to be related to the regulation of bone resorption and bone formation, bone remodeling after menopause becomes relatively inactive due to a decrease in the amount of hormone amount with the subsequent decrease in the mineral density of the bone. We designed a delivery system for several drugs using a biocompatible self-setting calcium phosphate cement which is transformed into hydroxyapatite in the body. The effect of plasma calcium levels on the oestradiol release from a self-setting apatite bone cement containing oestradiol in ovariectomized rats was investigated. The in-vitro release profiles from the cements in simulated body fluid containing 0.5 and 10mg/100mL calcium indicated that the oestradiol release rate decreased with increasing calcium concentration in dissolution media, suggesting that the in-vitro oestradiol release from apatite bone cement was dependent on the calcium concentration in the buffer. We applied this finding to the drug delivery system and reported that oestradiol release osteoporisi rats was greater than that observed in healthy rats after subcutaneous implantation of oestradiol-loaded cement, indicating that the in-vivo oestradiol release from apatite bone cement was dependent on plasma calcium levels.
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