@article {Wu:2008:0920-5063:411,
title = "Biodegradable hydrophobichydrophilic hybrid hydrogels: swelling behavior and controlled drug release",
journal = "Journal of Biomaterials Science, Polymer Edition",
parent_itemid = "infobike://tandf/bsp",
publishercode ="tandf",
year = "2008",
volume = "19",
number = "4",
publication date ="2008-04-01T00:00:00",
pages = "411-429",
itemtype = "ARTICLE",
issn = "0920-5063",
eissn = "1568-5624",
url = "https://www.ingentaconnect.com/content/tandf/bsp/2008/00000019/00000004/art00001",
doi = "doi:10.1163/156856208783719536",
keyword = "CONTROLLED RELEASE, HYDROPHILIC, HYBRID HYDROGEL, COCAINE METHIODIDE, HYDROPHOBIC",
author = "Wu, Da-Qing and Chu, Chih-Chang",
abstract = "The objective of this work was to investigate a new family of hydrophobichydrophilic biodegradable hybrid hydrogels as drug carriers. A series of hydrophobichydrophilic biodegradable hybrid hydrogels was formulated via photo means from hydrophobic three-arm poly
(-caprolactone) maleic acid (PGCL-Ma) and hydrophilic dextran maleic acid (Dex-Ma) precursors over a wide range of the two precursors' feed ratio (PGCL-Ma/Dex-Ma at 100:0, 70:30, 50:50, 30:70 and 0:100). A low-molecular-weight and hydrophilic drug, the -7 agonist
cocaine methiodide, was used as the model drug for the release study from the hybrid hydrogels in pH 7.4 phosphate buffer solution at 37\textdegreeC. The swelling data of these hybrid hydrogels depended on the hydrophobic to hydrophilic precursors' feed ratio, and there were several-fold differences
in swelling ratios between a pure hydrophilic Dex-Ma and a pure hydrophobic PGCL-Ma hydrogels. The presence of the hydrophobic PGCL-Ma component significantly reduced the initial burst swelling of the hybrid hydrogels. Depending on the two precursors' feed ratios, the swelling data during
the early period obeyed either Fickian diffusion (for 50:50 PGCL-Ma/Dex-Ma hydrogel), non-Fickian or anomalous transport (for 70:30 and 100:0 PGCL-Ma/Dex-Ma), or relaxation-controlled (for 30:70 and 0:100 PGCL-Ma/Dex-Ma). A wide range of cocaine methiodide release profiles was achieved by
controlling hydrophobic to hydrophilic precursors' feed ratios. Initial drug burst release was significantly reduced as the concentration of the hydrophobic PGCL-Ma component increased in the hybrid hydrogels. The bulk of cocaine methiodide released during the 160-h period was via diffusion-controlled
mechanism, while degradation-controlled mechanism dominated thereafter.",
}