Design, fabrication, and structural safety validation of 3D-printable biporous bone augments

Abstract

The use of commercial products such as a cup and liner for total hip arthroplasty for patients with severe bone defects has a high probability of failure. In these patients the cup alone cannot cover the bone defect, and thus, an additional augment or cage is required. In this study, we designed three-dimensional (3D) printable bone augments as an alternative to surgeries using reinforcement cages. Thirty-five sharp-edged bone augments of various sizes were 3D printed. A biporous structure was designed to reduce the weight of the augment and to facilitate bone ingrowth. Two types of frames were used to prevent damage to the augment’s porous structure and maintain its stability during printing. Furthermore, two types of holes were provided for easy augment fixation at various angles. Fatigue tests were performed on a combination of worst-case sizes derived using finite element analysis. The test results confirmed the structural stability of the specimens at a load of 5340 N. Although the porosity of the specimens was measured to be 63.70%, it cannot be said that the porous nature was uniformly distributed because porosity tests were performed locally and randomly. In summary, 3D-printable biporous bone augments capable of bonding from various angles and bidirectionally through angulation and bottom-plane screw holes are proposed. The mechanical results with bone augments indicate good structural safety in patients. However, further research is necessary to study the clinical applications of the proposed bone augment. Graphic abstract

Reactive Oxygen Species Responsive Nitric Oxide Release for Enhanced Photodynamic Antibacterial Therapy of Scaffolds

“…The implant-associated infection and bacterial resistance have long been a thorny issue. 1,2 According to reports, the implantassociated infection rate had reached as high as 15%, posing a huge threat to global healthcare. 3,4 Photodynamic therapy (PDT) had been a potential therapy due to its nonobvious drug resistance, high accuracy, and low systemic toxicity.…”

“…The implant-associated infection and bacterial resistance have long been a thorny issue. , According to reports, the implant-associated infection rate had reached as high as 15%, posing a huge threat to global healthcare. , Photodynamic therapy (PDT) had been a potential therapy due to its nonobvious drug resistance, high accuracy, and low systemic toxicity. , The basic principle of PDT relied entirely on the generation of reactive oxygen species (ROS) by photosensitizers in the presence of oxygen and light to kill bacteria. , The commonly used photosensitizers mainly included KNbO 3 (KN), g-C 3 N 4 , etc. , However, these photosensitizers commonly had the disadvantage of a fast electron–hole recombination rate, which led to low ROS production and thus weakened the effectiveness of PDT …”