| Summary: | 碩士 === 國立陽明大學 === 醫學工程研究所 === 87 === Methotrexate(MTX), the most widely used antimetabolite, is a folic acid antagonist. It has an essential role in the treatment of solid tumor and suppression of graft—versus—host disease. However, oral or intravenous treatment may lead to serve adverse effects. Alternative drug delivery system has been developed, including conjugation and encapsulation.
Liposomes are microscopic particles consisting of one or more spheres of phospholipid bilayers separated by aqueous compartment. Drug molecules can either be encapsulated in the aqueous phase or intercalated into the lipid bilayer depending on their own hydro— or lipophilicity. Liposome have great properties for drug delivery but is too largely cleared by the reticuloendothelial system, so we have to coat some bioadhesive to locate the liposomes. Collagen is a natural polymer purified from biological tissue. It has excellent biocompatibility and biodegradability, and is essential for tissue adhesion, which is a good liposome—composite material.
In this study, Liposomes were prepared by ether injection and membrane extrusion method, and with diameters about 200 nm. Liposome encapsulated MTX (liposome—MTX) is dispersed in collagen matrix as a drug delivery system, and the encapsulation ratio is 10%. The release property of liposome—MTX and liposome—MTX ¤ collagen is first order with equations ln (1—Q) = —0.000234t — 0.265 and ln (1—Q) = —0.000135—0.148, respectively, and release 80% drug in seven days.
Osteosarcoma cell line is selected to be In vitro model, and the 50% inhibitory dose (ID50) is assayed. Although the ID50 of liposome—MTX and liposome—MTX ¤ collagen are higher than free MTX, the difference is slightly and as a controlled release drug delivery system, the liposome—MTX ¤ collagen is an expectable bioadhesive controlled—release carriers.
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