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Researchers have attempted to develop efficient antithrombogenic surfaces, and yet small-caliber artificial vascular grafts are still unavailable. Here, we demonstrate the excellent patency of tissue-engineered small-caliber long-bypass grafts measuring 20–30 cm in length and having a 2-mm inner diameter. The inner surface of an acellular ostrich carotid artery was modified with a novel heterobifunctional peptide composed of a collagen-binding region and the integrin α4β1 ligand, REDV. Six grafts were transplanted in the femoral–femoral artery crossover bypass method. Animals were observed for 20 days and received no anticoagulant medication. No thrombogenesis was observed on the luminal surface and five cases were patent. In contrast, all unmodified grafts became occluded, and severe thrombosis was observed. The vascular grafts reported here are the first successful demonstrations of short-term patency at clinically applicable sizes. [ABSTRACT FROM AUTHOR]

Using a simple and innovative sandblasting process, disks of monolithic biomedical silicon nitride (β-Si 3 N 4) were texturized with a matrix of regular, discrete square trenches with a total depth in the range of hundreds of microns. The process consisted of sandblasting Si 3 N 4 substrates through a stainless-steel wire-mesh (150 or 200 μm) using abrasive silicon carbide powders (α -SiC, ∼40 μm) under 1,034 kPa (150 psi) of gas pressure. The depth of the porosities could be controlled varying both the treatment time and the distance from the surface. Part of the samples were then filled with 45S5 Bioglass® powders to improve the osteointegration and stimulate the production of bone tissue. Due to the increased macroscopic and microscopic roughness, biological testing using human osteosarcoma cells (SaOS-2) showed improved cell proliferation and greater production of both mineral (hydroxyapatite) and organic (collagen) phases on the patterned surfaces compared to untreated β-Si 3 N 4 or to the biomedical titanium control samples. Both of these effects were further enhanced when the porosities were filled with Bioglass®. • Textured sandblasting has been used for the first time on the surface of silicon nitride. • A steel wire mesh was used to mask the silicon nitride surface during processing. • The textured surface proved to be more osteoinductive compared to polished silicon nitride. • Addition of 45S5 bioglass further enhanced the production of bone tissue by SAOS-2 osteosarcoma cells. [ABSTRACT FROM AUTHOR]