Polyether-ether-ketone (peek) is one of the most common materials used for load-bearing orthopedic devices owing to its radiolucency and favorable mechanical properties. However, current smooth-surfaced peek implants can lead to fibrous capsule formation. To overcome this issue, here, peek specimens with well-defined internal cross-linked structures (macropore diameters of 1.0–2.0 mm) were fabricated using a three-dimensional (3D) printer, and an acid-etched microporous surface was achieved using injection-molding technology. The cell adhesion properties of smooth and microporous peek specimens was compared in vitro through a scanning electron microscope (SEM), and the soft tissue responses to the both microporous and cross-linked structure of different groups were determined in vivo using a New Zealand white rabbit model, and examined through histologic staining and separating test. The results showed that the acid-etched microporous surface promoted human skin fibroblasts (HSF) adherence, while internal cross-linked structure improved the ability of the peek specimen to form a mechanical combination with soft tissue, especially with the 1.5 mm porous specimen. The peek specimens with both the internal cross-linked structure and external acid-etched microporous surface could effectively promote the close integration of soft tissue and prevent formation of fibrous capsules, demonstrating the potential for clinical application in surgical repair.

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In this work, two identical sequencing batch reactors (SBRs) with mature aerobic granules were utilized to treat synthetic high-strength ammonium wastewaters with chemical oxygen demand (COD)/total nitrogen (TN) ratios of 3.9-6.9. The contributions of various mechanisms to the removal of ammonium were determined. Ammonium levels of 600-2000 mg-N l-1 had little adverse effect on the COD removal rate (91.6%-95.3%) with an influent COD of 4490-9860 mg l-1. The TN removal rate was slightly reduced from 71.3% to 59.6% as the influent ammonium concentration was increased from 600 to 2000 mg-N l-1. Experimental results indicated that aerobic granules removed 94.5% of COD and 59.6% of TN in the treatment of synthetic high-strength wastewater (9860 mg-COD l-1 and 2000 mg NH+4-Nl-1) during a 12 h cycle. Granular adsorption, air stripping and conversion by nitrification/denitrification were responsible for removing 9%, 15% and 76%, respectively, of the total removed NHf -N. Dissolved oxygen (DO) was a useful process indicator of the biological reactions in the treatment of high-level ammonium wastewaters.