Type 2 diabetes mellitus (T2DM), and the often concurrent obesity, causes metabolic changes that affect many organs and tissues, including bone. Despite a normal or even higher bone mineral density (BMD), T2DM has often been associated with a higher fracture risk, indicating a compromised bone quality. In this work, we use a novel congenic leptin receptor-deficient BioBreeding Diabetes Resistant rat (BBDR.cg.lepr.cp) to investigate the impact of T2DM and obesity on bone morphology and architecture at the microscale. Two different anatomical locations, i.e., femur and cranium, were studied combining micro-computed X-ray tomography (micro-CT) with scanning electron microscopy (SEM). Micro-CT data were examined using advanced image analysis tools in three-dimensions (3D).Introduction and Objective
Materials and Methods
Calcium phosphates are among the most commonly used bone graft substitute materials. Compositions containing predominantly monetite (∼84.7%) with smaller additions of beta-tricalcium phosphate (β-TCP; ∼8.3%) and calcium pyrophosphate (Ca-PP; ∼6.8%) have previously been demonstrated to exhibit osteoinductive properties. Such a multi-component calcium phosphate bioceramic was fashioned in the form of hollowed-out, dome-shaped devices (15 mm diameter, 4 mm height), each reinforced with a 3D printed Ti6Al4V ELI frame. With the aim to induce bone formation beyond the skeletal envelope, these devices were investigated in vivo using a sheep (Ovis aries) occipital bone model. The bioceramic composition was prepared from a mixture of β-TCP/dicalcium pyrophosphate and monocalcium phosphate monohydrate powders mixed with glycerol. The Ti6Al4V ELI frame was positioned into a dome-shaped mould and bioceramic paste was poured over the frame and allowed to set, in sterile water, prior to removal from the mould. In adult female sheep (n=7), the devices were positioned directly over the bone and stabilised using self-drilling screws. After 52 weeks, the devices were retrieved, resin embedded, and used for X-ray micro-computed tomography (micro-CT), histology, backscattered electron scanning electron microscopy (BSE-SEM), energy dispersive X-ray spectroscopy (EDX), micro-Raman spectroscopy, and Fourier transform infrared spectroscopy (FTIR).Introduction and Objective
Materials and Methods