Study the property of double-ended fluoroalkyl poly(ethylene glycol) hydrogel as a depot for hydrophobic drug delivery using electron paramagnetic resonance technique and cell proliferation assay

• Published in: Journal of sol-gel science and technology 2008-03, Vol.45 (3), p.269-278
• Main Authors: Liu, Xiangli, Mao, Yougang, Mathias, Errol V., Ma, Collin, Franco, Osmundo, Ba, Yong, Kornfield, Julia A., Wang, Tieli, Xue, Lijun, Zhou, Bing-Sen, Yen, Yun
• Format: Article
• Language: English
• Subjects: Biocompatibility; Cell growth; Ceramics; Chemistry; Chemistry and Materials Science; Colloidal gels. Colloidal sols; Colloidal state and disperse state; Composites; Drug delivery systems; Electron paramagnetic resonance; Electron spin; Exact sciences and technology; General and physical chemistry; Glass; Hydrogels; Hydrophobicity; Inorganic Chemistry; Materials Science; Micelles; Nanotechnology; Natural Materials; Optical and Electronic Materials; Original Paper; Polyethylene glycol; Sol-gel processes; Temperature dependence
• ISSN: 0928-0707; 1573-4846
• DOI: 10.1007/s10971-007-1659-y

Hydrogel formed by fluoroalkyl double-ended polyethylene glycol (R f -PEG) micelles was studied to assess its properties to encapsulate a hydrophobic electron spin labeled drug, Chlorambucil–Tempol adduct (CT), and to control and sustain the drug release. The drug loaded hydrogel samples were characterized with variable-temperature dependent EPR experiment, and EPR theoretical lineshape analysis. It was found that CT molecules reside in the hydrophobic R f -cores/IPDU shells of the R f -PEG micelles and the maximum molecular-level loading capacity was estimated to be 18.8 mg per gram of the R f -PEG. It has been known that R f -PEG hydrogel with certain molecular masses for the fluoroalkyl group and the PEG chain shows properties of sol/gel phase coexistence and surface erosion, which represent the favorable condition for a pharmaceutical depot to control the kinetics of drug release. To evaluate the R f -PEG’s biocompatibility and kinetics of the drug release, a cell proliferation assay was carried out on human oropharyngeal carcinoma (KB) cells. The results show that R f -PEG is biocompatible and able to release CT to the cell media with a constant equilibrium concentration independent of the amount of CT loaded hydrogel.