A New Rat Model for Translational Research in Bone Regeneration

Abstract

The European Union (EU) directive 2010/63/EU on the protection of animals used for scientific purpose focused on reducing the number of animals and refinement of breeding. Animal studies are necessary to protect human health. Lots of animal models exist to study bone regeneration, but a reliable, well reproducible, and relatively inexpensive model with the possibility for multiple testing in the same animal is still missing. Rats may serve as good models for this due to the small animal size and good cost/benefit ratio. The present study aimed to develop a novel rat caudal vertebrae critical size defect model for bone regeneration and implant osseointegration studies The study was performed using Wistar rats with weight from 380 to 450 g. An incision was made on the dorsal side of the tail. After skin and muscles retractions, the vertebrae were exposed. Critical size defects for bone tissue engineering or implant placements for titanium body experiments were possible in each of the first four caudal vertebrae. Micro-computed tomography (CT) and histology were used to detect bone growth. There was no bone formation in the defects after 1 or 2 months of healing. When a calcium phosphate biomaterial was used (Bio-Oss; Geistlich Pharma AG, Wolhusen, Switzerland), a good stability of the material in the defect was noted and bone growth was visible after 1 or 2 months. Results based on implant placement showed good primary stability after 3 months of healing. MicroCT showed integrated implant position through the vertebra. These results suggest that the rat caudal vertebrae may serve as a good new model for studying bone regeneration and implant osseointegration with the possibility of multiple testing within the same experimental animal and the potential to decrease number of experimental animals.

Suppressing inflammation and enhancing osteogenesis using novel CS‐EC@Ca microcapsules

“…CS and EC, as the shell material of microcapsules, are not cytotoxic and degradable and can therefore promote cell proliferation . The main histological findings in our study revealed significant degradation of the microcapsules, especially in the period from 4 to 12 weeks, whereas the Bio‐oss was only slightly degraded at 4 weeks after surgery and showed no obvious further degradation at 12 weeks after surgery, which is consistent with previous reports . Moreover, the drug release from the CS‐EC@Ca microcapsules is steady and sustained for osteogenesis, and with inner drug release, a perforated channel structure is formed, which is conducive to cell adhesion and proliferation .…”

“…28,29 The main histological findings in our study revealed significant degradation of the microcapsules, especially in the period from 4 to 12 weeks, whereas the Bio-oss was only slightly degraded at 4 weeks after surgery and showed no obvious further degradation at 12 weeks after surgery, which is consistent with previous reports. 30 Moreover, the drug release from the CS-EC@Ca microcapsules is steady and sustained for osteogenesis, and with inner drug release, a perforated channel structure is formed, which is conducive to cell adhesion and proliferation. 14 Bio-Oss, on the other hand, degrades slowly and remains even 11 years after implantation, which hampers further bone formation and full regeneration in those areas.…”

Can implants move in bone? A longitudinal in vivo micro‐CT analysis of implants under constant forces in rat vertebrae

“…It was first described by M. L. Wang, Massie, Perry, Garfin, and Kim (2007) for analyzing the impact of bone loading in osteoporotic animals. It was introduced to dentistry in 2016 by Renaud et al (2016) and further described by Farkasdi et al (2018). It may be questioned to what extent residual growth of the rat vertebrae had an impact on the findings of the present investigation.…”

“…It was first described by M. L. Wang, Massie, Perry, Garfin, and Kim () for analyzing the impact of bone loading in osteoporotic animals. It was introduced to dentistry in 2016 by Renaud et al () and further described by Farkasdi et al (). A big advantage of this animal model is the relative ease of interoperative accessibility, and, due to the small size of the tail, high‐resolution μCT images can be obtained from living animals.…”

Clinical application of triangular parabolic PEEK mesh with hole button produced by combining CAD, FEM and 3DP into cranioplasty

“…Due to the attenuation of the rays of titanium repair, it will result in some pseudo shadow in the CT and X-ray image. HM Li and others utilized electron spin resonance to study free radical attenuation of PEEK and discovered that there's no radical 20 min after radiation (600 kGray) on PEEK, so PEEK was not considered a secondary radiation source after gamma-ray sterilization [19,20]. PEEK has outstanding advantages on the biocompatibility, no toxin, no immunity, no allergens.…”