Abstract
One of the major limitations during titanium (Ti) implant osseointegration is the poor cellular interactions at the biointerface. In the present study, the combined effect of recombinant human Bone Morphogenetic Protein-2 (rhBMP-2) and nanopatterned Ti6Al4V fabricated with Directed irradiation synthesis (DIS) is investigated in vitro. This environmentally-friendly plasma uses ions to create self-organized nanostructures on the surfaces. Nanocones (≈36.7 nm in DIS 80°) and thinner nanowalls (≈16.5 nm in DIS 60°) were fabricated depending on DIS incidence angle and observed via scanning electron microscopy. All samples have a similar crystalline structure and wettability, except for sandblasted/acid-etched (SLA) and acid-etched/anodized (Anodized) samples which are more hydrophilic. Biological results revealed that the viability and adhesion properties (vinculin expression and cell spreading) of DIS 80° with BMP-2 were similar to those polished with BMP-2, yet we observed more filopodia on DIS 80° (≈39 filopodia/cell) compared to the other samples (<30 filopodia/cell). BMP-2 increased alkaline phosphatase activity in all samples, tending to be higher in DIS 80°. Moreover, in the mineralization studies, DIS 80° with BMP-2 and Anodized with BMP-2 increased the formation of calcium deposits (>3.3 fold) compared to polished with BMP-2. Hence, this study shows there is a synergistic effect of BMP-2 and DIS surface modification in improving Ti biological properties which could be applied to Ti bone implants to treat bone disease.
Highlights
Bone loss affects more than half a million patients in the United States and represents over $2.5 billion in health costs
We observed that the presence of BMP-2 in cells growing on Directed irradiation synthesis (DIS) 80◦ samples showed higher surface area, increasing cellular spreading by 120% compared to its counterpart without the protein, but no statistical differences were found compared to polished samples with BMP-2 (Figure 7b)
yes-associated protein (YAP) is a member of the Hippo Signaling pathways that shuttles between the cytoplasm and the nucleus under specific physical cues, e.g., stiffness and topography, acting as a promoter for osteogenic transcription factors; inducing mesenchymal stem cells (MSC)
Summary
Bone loss affects more than half a million patients in the United States and represents over $2.5 billion in health costs. There is an urgent need to improve titanium bone contact to accelerate healing times, avoid implant failure, and minimize secondary surgeries to remove it, reducing the associated costs and increasing the patient0 s quality of life [3,7,8] Framed into this special issue, researchers from a multidisciplinary field (e.g., engineers, biologists, physicists, pharmacists) have joined their knowledge and expertise to develop smart biomaterials that address essential health concerns. DIS shows multiple advantages compared to conventional nanopatterning techniques or new sintering methods, it is a fast process, reliable, with strong capacity to tune small nanofeatures (10 to 1000 s nm) without the use of masks [29], high temperature [35] or toxic reagents [32,33] This bottom-up technique has previously shown the capability to tailor nanofeatures on Ti surfaces keeping the bulk properties stable when using low fluences. To the best of our knowledge, this is the first study that does a systematic study using ion-induced surface patterning techniques in synergy with biologics compared with industry-leading anodized and sandblast surface treatment technologies
Sign-in/Register to view highlights & summary 
Published Version (
Free)
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call