In Vitro Study of the Interaction of Innate Immune Cells with Liquid Silicone Rubber Coated with Zwitterionic Methyl Methacrylate and Thermoplastic Polyurethanes

Abstract

The biocompatibility of medical devices, such as implants and prostheses, is strongly determined by the host’s immune response to the implanted material. Monocytes and macrophages are main actors of the so-called foreign body reaction. The innate immune system macrophages (M) can be broadly classified into the pro-inflammatory M1-type and the anti-inflammatory, pro-healing M2-type. While a transient inflammatory initial state can be helpful during an infection, persistent inflammation interferes with proper healing and subsequent regeneration. The functional orientation of the immune response, mirrored by monocyte polarization, during interaction with different biomaterials has not yet been sufficiently explored. In implant manufacturing, thermoplastic polyurethane (TPU) represents the state-of-the-art material. The constantly growing areas of application and the associated necessary adaptations make the optimization of these materials indispensable. In the present study, modified liquid silicone rubber (LSR) were compared with two of the most commonly used TPUs, in terms of monocyte adhesion and M1/M2 polarization in vitro. Human monocytes isolated from venous blood were evaluated for their ability to adhere to various biomaterials, their gene expression profile, and their cytokine release. Based on the results, the different polymers exhibit different potential to bias monocytes with respect to early pro-inflammatory cytokine production and gene transcription. Furthermore, none of our test materials showed a clear trend towards M1 or M2 polarization. However, we were able to evaluate the inflammatory potential of the materials, with the classic TPUs appearing to be the most unreactive compared to the silicone-based materials.

Bacterial Adhesion and Biofilm Formation of Enterococcus faecalis on Zwitterionic Methylmethacrylat and Polysulfones

“…Two thermoplastic polyurethanes (TPU) and liquid silicone rubber (LSR) were used, either with or without modification. Further details on the preparation are described in our previous work ( Woitschach et al., 2021a ; Woitschach et al., 2021b ). After modification, all samples were subjected to a sterilization process with ethylene oxide (ETO).…”

Modeling the neuroimmune system in Alzheimer’s and Parkinson’s diseases

“…Bioprinted 3D scaffolds containing macrophages and antibiotics have also been used to reduce Staphylococcus aureus bacterial burdens during infections [ 139 , 140 ]. This knowledge can be employed to develop innovative strategies for tissue regeneration, immune modulation, and the design of biomaterials that promote favorable immune interactions [ 141 ].…”

3D Scan to Knit - Workflow and Challenges of Automated Data Processing and Knit Program Generation for Prosthesis Liners

“…It can be a knitted structure coated with silicone or be made of elastomeric materials (gel or silicone) only (see figure 2). Silicon is chosen because of its biocompatibility, flexibility and high friction coefficient with skin [5,28]. The connection between Liner and prothesis is either facilitated only trough friction, or by using a pin, which is attached to the liner and locks into the prothesis [29].…”