| 1. |
- Jo, Yunsuk, et al.
(author)
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Mathematical modelling on the controlled-release of indomethacin-encapsulated poly(lactic acid-co-ethylene oxide) nanospheres
- 2004
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In: Nanotechnology. - : IOP Publishing. - 0957-4484 .- 1361-6528. ; 15:9, s. 1186-1194
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Journal article (peer-reviewed)abstract
- The in vitro release behaviour of indomethacin (IMC, 1-[p-chlorobenzoyl]-2-methyl-5-methoxy-3-indoleacetic acid) encapsulated in poly(lactic acid-co-ethylene oxide) (PLA-PEO) nanospheres is investigated based on two mathematical models: the diffusion model derived from Fick's law and the dissolution model from the mass balance of IMC. A dual chamber transport system (DCTS) is designed and used for the in vitro experiment. The release behaviour of IMC from the PLA-PEO drug delivery systems (DDSs) is compared to the mathematical models suggested in this work. The synthesis of PLA-PEO and the fabrication of the IMC-loaded PLA-PEO DDSs are discussed and characterized by H-1 NMR, transmission electron microscopy (TEM) and quasi-elastic light scattering (QELS) spectroscopy. Spherical PLA-PEO nanospheres are well prepared as a model DDS as suggested by the characterization results. The overall releasing behaviour of the model drug can be manipulated by varying several key parameters including the volumetric ratio between the organic and the aqueous phase (V-r), the partition coefficient (K-p) and the encapsulation efficiency (EE). Modelling results show that the releasing mechanism is different depending on the particle size. When large PLA-PEO nanospheres are fabricated, the dissolution mechanism can be effective, as the dissolution of IMC can be a rate-determining step due to its high hydrophobicity in an aqueous surrounding medium. In this manner, the optimum DDS can be suitably designed and the releasing profile can be also estimated by considering several major factors for a specific type of substance and its purpose.
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| 2. |
- Jo, Yunsuk, et al.
(author)
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A novel thermosensitive composite fabricated with au nanoparticles, poly(lactide), and poly(N-isopropylacrylamide)
- 2004
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In: Functional Nanomaterials For Optoelectronics And Other Applications. ; , s. 161-164
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Conference paper (peer-reviewed)abstract
- A novel approach to load a hydrophilic bovine serum albumin (BSA) into the drug carriers was proposed in terms of thermosensitive dual-shell structures which were fabricated with poly(N-isopropylacrylamide), poly(lactide) and Au nanoparticles. Spherically well-defined dual-shell structures were constructed by a modified-double-emulsion method (MDEM). The lower critical solubility temperature of the structures was shifted to 36.4 degreesC which was confirmed by UV-Vis spectroscopy.
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