Conditions of lateral surface confinement that promote tissue-cell integration and inhibit biofilm growth

Surfaces with cell adhesiveness modulated at micro length scales can exploit differences between tissue/bacterial cell size, membrane/wall plasticity, and adhesion mechanisms to differentially control tissue-cell/material and bacteria/material interactions. This study explores the short-term interactions of Staphylococcus aureus and osteoblast-like cells with surfaces consisting of cell-adhesive circular patches (1–5 μm diameter) separated by non-adhesive electron-beam patterned poly(ethylene glycol) hydrogel thin films at inter-patch distances of 0.5–10 μm. Osteoblast-like U2OS cells both bind to and spread on the modulated surfaces, in some cases when the cell-adhesive area comprises only 9% of the total surface and in several cases at least as well as on the continuously adhesive control surfaces. In contrast, S. aureus adhesion rates are 7–20 times less on the modulated surfaces than on the control surfaces. Furthermore, the proliferation of those bacteria that do adhere is inhibited by the lateral confinement imposed by the non-adhesive boundaries surrounding each patch. These findings suggest a new approach to create biomaterial surfaces that may promote healing while simultaneously reducing the probability of infection.