Impact of topography and added TiN-coating on adult human dermal fibroblasts after seeding on titanium surface in-vitro

Abstract

Complications of transcutaneous osseointegrated prosthetic systems (TOPS) focus on the metal-cutaneous interface at the stoma. Besides pain due to scare tissue as well as undefined neuropathic disorders, there is high evidence that the stoma presents the main risk causing hypergranulation and ascending infection. To restore the cutaneous barrier function in this functional area, soft-tissue on- or in-growth providing a vital and mechanically stable bio-artificial conjunction is considered a promising approach. In this study we assessed viability and proliferation of adult human dermal fibroblasts (HDFa) on modifications of a standard prosthetic titanium surface. Un-coated (TiAl6V4) as well as a titanium-nitrite (TiN) coated additive manufactured porous three-dimensional surface structures (EPORE®) were seeded with HDFa and compared to plain TiAl6V4 and polystyrene surfaces as control. Cell viability and proliferation were assessed at 24 h and 7 days after seeding with a fluorescence-based live-dead assay. Adhesion and cell morphology were analyzed by scanning electron microscopy at the respective measurements. Both EPORE® surface specifications revealed a homogenous cell distribution with flat and spread cell morphology forming filopodia at both measurements. Proliferation and trend to confluence was seen on un-coated EPORE® surfaces with ongoing incubation but appeared substantially lower on the TiN-coated EPORE® specification. While cell viability on both EPORE® specifications was comparable to plain TiAL6V4 and polystyrene controls, cell proliferation and confluence were less pronounced when compared to controls. The EPORE® topography allows for fibroblast adhesion and viability in both standard TiAl6V4 and – to a minor degree - TiN-coated specifications as a proof of principle.

Analyzing the Surface Topography of Hafnium Nitride Coating on Titanium Screws: An In Vitro Analysis

“…Another drawback is that many in vitro evaluations do not predict or correlate with in vivo performance. This said, in a few culture models, surface characterization positively affects osteogenic cellular activities [4,22,23].…”

“…These challenges led to the idea of surface coatings over titanium to improve the mechanical, biological, and physical properties of titanium alloy [3]. Surface coatings have been widely researched in recent times to alleviate problems associated with titanium implants [4,5].…”

“…This hafnium metal coating of commercially available titanium implants has proven to show some superior properties to titanium with in vitro studies and soft tissue [11][12][13]. Hafnium nitride (HfN) coatings could be explored as promising in the osteoinductive properties of titanium implants [4,[14][15][16].…”