Early fragmentation of polyester urethane sheet neither causes persistent oxidative stress nor alters the outcome of normal tissue healing in rat skin

Inflammatory response to various implant surfaces in murine models: A systematic analysis

Breast implants (BIs) are commonly used in cosmetic and reconstructive breast surgery but are linked to several complications such as capsular contracture, implant rupture, and potential malignancies. The key to mitigating these issues is the exploration of host-implant interactions, especially in response to the diverse BI surface textures, classified under ISO 14607:2018 standards. We aimed to systematically analyze the effects of different BI surface textures on inflammatory response and capsule formation in murine models, to improve BI design and clinical outcomes. A PRISMA-guided systematic review was conducted across 4 databases, focusing on murine model studies related to BI surface variations. Non-murine, human studies and those involving physical or pharmacological interventions were excluded. Implant surfaces were categorized per ISO 14607:2018, including smooth, microtextured, macrotextured, and polyurethane foam-coated (PU) BI, and compared with new ISO 14607:2018. Outcomes were assessed on capsule characteristics, inflammatory patterns, and biomechanical properties. Smooth-surfaced implants were linked to thinner, more orderly capsules, with a subdued inflammatory reaction. Microtextured implants elicited a moderate response with varying tissue integration and inflammation levels. Macrotextured implants showed pronounced tissue reaction. PU implants induced a robust inflammatory response, characterized by increased neoangiogenesis and thicker, more cellular capsules. Data inconsistencies across studies highlighted the complexity of biological responses to different implant surfaces. In conclusion, smooth implants developed thinner capsules and lower inflammation. Increasing surface texture resulted in denser capsules and more abundant inflammatory patterns, highlighting the significant role of BI surface texture in influencing host responses.

In vitro degradation profiles and in vivo biomaterial-tissue interactions of microwell array delivery devices

To effectively apply microwell array cell delivery devices their biodegradation rate must be tailored towards their intended use and implantation location. Two microwell array devices with distinct degradation profiles, either suitable for the fabrication of retrievable systems in the case of slow degradation, or cell delivery systems capable of extensive remodeling using a fast degrading polymer, were compared in this study. Thin films of a poly(ethylene glycol)‐poly(butylene terephthalate) (PEOT‐PBT) and a poly(ester urethane) were evaluated for their in vitro degradation profiles over 34 weeks incubation in PBS at different pH values. The PEOT‐PBT films showed minimal in vitro degradation over time, while the poly(ester urethane) films showed extensive degradation and fragmentation over time. Subsequently, microwell array cell delivery devices were fabricated from these polymers and intraperitoneally implanted in Albino Oxford rats to study their biocompatibility over a 12‐week period. The PEOT‐PBT implants shown to be capable to maintain the microwell structure over time. Implants provoked a foreign body response resulting in multilayer fibrosis that integrated into the surrounding tissue. The poly(ester urethane) implants showed a loss of the microwell structures over time, as well as a fibrotic response until the onset of fragmentation, at least 4 weeks post implantation. It was concluded that the PEOT‐PBT implants could be used as retrievable cell delivery devices while the poly(ester urethane) implants could be used for cell delivery devices that require remodeling within a 4–12 week period.