Dexamethasone released from cochlear implant coatings combined with a protein repellent hydrogel layer inhibits fibroblast proliferation

Autor: Antonina Wrzeszcz, Ingo Nolte, Günter Reuter, Barbara Dittrich, Thomas Lenarz, Daniel Haamann, Pooyan Aliuos, Doris Klee
Rok vydání: 2013
Předmět:
Zdroj: Journal of Biomedical Materials Research Part A. 102:442-454
ISSN: 1549-3296
Popis: The insertion of cochlear implants into the inner ear often causes inflammation and fibrosis inside the scala tympani and thus growth of fibrous tissue on the implant surface. This deposition leads to the loss of function in both electrical and laser-based implants. The design of this study was to realize fibroblast growth inhibition by dexamethasone (Dex) released from the base material of the implant [polydimethylsiloxane (PDMS)]. To prevent cell and protein adhesion, the PDMS was coated with a hydrogel layer [star-shaped polyethylene glycol prepolymer (sPEG)]. Drug release rates were studied over 3 months, and surface characterization was performed. It was observed that the hydrogel slightly smoothened the surface roughened by the Dex crystals. The hydrogel coating reduced and prolonged the release of the drug over several months. Unmodified, sPEG-coated, Dex-loaded, and Dex/sPEG-equipped PDMS filaments were cocultivated in vitro with fluorescent fibroblasts, analyzed by fluorescent microscopy, and quantified by cell counting. Compared to the unmodified PDMS, cell growth on all modified filaments was averagely 95% ±standard deviation (SD) less, while cell growth on the bottom of the culture dishes containing Dex-loaded filaments was reduced by 70% ±SD. Both, Dex and sPEG prevented direct cell growth on the filament surfaces, while drug delivery was maintained for the duration of several months.
Databáze: OpenAIRE
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