Increased connective tissue attachment to silicone implants by a water vapor plasma treatment

Abstract

Polydimethylsiloxane (PDMS) is the most common type of silicone polymer for the fabrication of implantable medical devices. Because of its inherent hydrophobic nature, the PDMS surface does not readily promote cellular adhesion, which leads to diverse clinical issues. Previously, we reported a simple water vapor plasma treatment of PDMS surfaces that resulted in stable long-term wettability and excellent in vitro cell compatibility. In this work, we report investigation of the in vivo local responses to PDMS implants treated by water vapor plasma using a subcutaneous rat model. The local tissue responses were assessed after 2 and 4 weeks of implantation by means of macroscopic and histomorphometric analysis. After 2 weeks of implantation, the plasma-treated implants elicited the formation of fibrous tissue capsules that were significantly thinner, more adherent, and vascularized than the control counterparts. The improved cell adhesion was correlated with an increased amount of cells attached to the implant surface after retrieval. There was no difference in the inflammatory response between untreated and treated samples. This study provides a rational approach to optimize the long-term performance of silicone implants, which is likely to have a significant impact in clinical applications demanding enhanced tissue integration of the implants.

Plasma-Assisted Hydrophilization of Cochlear Implant Electrode Array Surfaces Enables Adhesion of Neurotrophin-Secreting Cells

“…In particular, the fabrication of an electrode array colonized with adjuvant or functionalized cells may be enabled. Moreover, enhanced cell adhesion may prevent a ‘dead space' between the implant and the soft tissue, as reported in the literature [8], and may reduce the foreign body reaction resulting from fibrous capsule formation around silicone implants [7,8], both of which may lead to a reduction in electrical impedance. Furthermore, the reduction of the ‘dead space' can lead to fewer implant-associated infections or implant dislocations [7,8].…”

“…In contrast, in the evaluation of the cell number after labeling the cell nuclei, washing steps are not required and hASCs, even if insufficiently adherent, may have remained on the silicone surface. In an in vivo experiment in rats, Jensen et al [8] also found statistically significant enhanced cell adhesion to plasma-treated versus untreated silicone surfaces. Hauser et al [7] found an increase in cell adherence as well, even though the difference did not prove to be statistically significant.…”

“…In addition, the hydrophobic character of silicone limits both its wettability and biocompatibility [7]. It has been shown, however, that plasma-assisted treatments can be used to modify silicone surfaces of medical implants to enhance cell adherence and biocompatibility [8]. …”

A polydopamine peptide coating enables adipose‐derived stem cell growth on the silicone surface of cochlear implant electrode arrays

“…[13][14][15] Another method represents cold plasma-assisted modification of silicone surfaces, which enables improved cell adherence and hydrophilicity. 16 Recently, Lee et al 17 described bioinspired polydopamine (PD)-based coating as a simple method for surface Correspondence to: P. Schendzielorz; e-mail: Schendziel_P@ukw.de functionalization. With this technique, mussel-derived dopamine molecules polymerize in alkaline pH to form thin films on various surfaces.…”

Alleviation of capsular formations on silicone implants in rats using biomembrane-mimicking coatings

“…Hydroxylated silicone implants showed a similar decrease in capsular thickness with PMPC-coated silicone implants in this study, but the inflammation score was not different from that of the untreated silicone [39]. Plasma-and collagen-coated silicones enhanced adhesion of cells and increased angiogenesis in peri-implant tissues [40].…”