Microgrooved subcutaneous implants in the goat

Abstract

We investigated the behavior of microgrooved implants in soft tissue using polystyrene implantable disks, either smooth or microgrooved (1-10 microm) on both sides. The implants were placed subcutaneously in a goat for 1, 4, or 12 weeks. Light and transmission electron microscopy showed that fibrous capsule formation around the implants was fairly uniform. After 1 week the implants were covered with a fibrous capsule about 80 microm thick. The collagen matrix was loose, and many inflammatory cells were present. After 4 weeks the matrix was more dense and contained many newly formed blood vessels. At the implant surface a layer of inflammatory cells about 10 microm thick had accumulated. Finally, after 12 weeks the matrix had densified. One cellular layer of inflammatory cells was present at the implant surface. We carried out histomorphometric measurements of capsule thickness, inflammatory layer thickness, and the number of blood vessels. Capsule thickness appeared not to decrease with time. Further, these measurements showed that there were no differences in tissue reaction between smooth and microgrooved implants. On the basis of our observations, we suggest that 1 microm deep and 1-10 microm wide microgrooves do not influence tissue response around polystyrene implants in soft tissue.

Effect of microtextured surfaces on the performance of percutaneous devices

“…The microgrooves in the silicone were directed either parallel to the long axis of the catheter (with grooves directed perpendicular to the skin) or circular around the catheter (parallel to the skin). Based on previous animal studies within our group, and the group of Brunette and coworkers, one of two types of texturing were applied: either 10‐μm‐wide and 1‐μm‐deep grooves,2–9 or 40‐μm‐wide V‐shaped grooves 10–13. The dimensions of the various implants are shown in Table I.…”

“…Although microtexturing is known to have vast influence on the growth behavior of cells in vitro , current in vivo literature is scarce and does not demonstrate the applicability of microtexturing. For instance, a number of recent studies showed that microtexturing had no evident beneficial effects on the performance of soft‐tissue implants 5–9. In these studies, even an aggravated attraction of macrophages to textured surfaces was seen.…”

Biomechanics of the Sensor-Tissue Interface—Effects of Motion, Pressure, and Design on Sensor Performance and the Foreign Body Response—Part I: Theoretical Framework

“…93 Stresses in this range (1-10 nN/cell contact) can cause remodeling of cell-cell contacts, cell extracellular matrix (ECM), and ECM. 42 Capsular contracture arising from constriction of the foreign body capsule has been reported to be strong enough to bend and fracture subcutaneously implanted polystyrene disks 94 and rupture breast implants. 95,96 Capsular contraction may not be relevant to available PerQ sensors but will become more relevant to sensor applications as the lifetime of fully implantable sensors is extended beyond 1-week implantation time.…”

Surface Modification of Biomedical and Dental Implants and the Processes of Inflammation, Wound Healing and Bone Formation

“…This property of “contact guidance” is an important part of understanding the behavior of how pre-osteoblasts interact with the complex fibrin/platelet scaffold. There are a number of elegant in vitro and in vivo studies which document the importance of not just the roughness of an implant surface but the effect of the direction of the pattern (or epitaxis) [108–111]. These studies demonstrate that fibroblasts and osteoblasts are capable of recognizing repeated surface features (e.g., lines, grooves and other defects created in machining).…”