A bioactive two-layer coating consisting of hydroxyapatite (HA) and yttria-stabilized zirconia (YSZ) was investigated on cylindrical polyetheretherketone (PEEK) implants using ion beam assisted deposition (IBAD). Post-deposition heat treatments via variable frequency microwave annealing with and without subsequent autoclaving were used to crystallize the as-deposited amorphous HA layer.
A novel nonviral gene delivery tool of BMP-2 for the reconstitution of critical-size bone defects in rats
Outstanding Mechanical Response and Bone Regeneration Capacity of Robocast Dilute Magnesium-doped Wollastonite Scaffolds in Critical Size Bone Defect
The regeneration and repair of damaged load-bearing segmental bone requires considerable mechanical strength for the artificial implants. The ideal biomaterials should also facilitate the production of porous implants with high bioactivity desirable for stimulating new bone growth. Here we developed a new mechanically strong, highly bioactive, dilute magnesium-doped wollastonite (CaSiO3-Mg; CSi-Mg) porous scaffold by the robocasting technique. The sintered scaffolds had interconnected pores of 350 μm in size and over 50% porosity with appreciable compressive strength (>110 MPa), 5−10 times higher than those of pure CSi and β-TCP porous ceramics. ...
Peri-implant defect regeneration in the diabetic pig: a preclinical study
Authors
Cornelius von Wilmowsky, Karl Andreas Schlegel, Christoph Baran, Emeka Nkenke, Friedrich Wilhelm Neukam, Tobias Moest
Abstract
Objectives
The study aims to establish a peri-implant dehiscence-type bone defect in a diabetic animal model of human bone repair and to quantify the influence of diabetes on peri-implant bone regeneration.
Material and methods
Experimental diabetes was induced in three domestic pigs by streptozotocin. Three animals served as healthy controls. After 12 months four standardized peri-implant dehiscence bone defects were surgically created in the ramus mandibulae. The animals were sacrificed after 90 days. Samples were histologically analyzed to quantify new bone height (NBH), bone-to-implant-contact (BIC), area of newly formed bone (NFB), bone-density (BD), and bone mineralization (BM) in the prepared defect (- D) and in a local control region (-L).
Results
After 90 days, diabetic animals revealed a significantly lower BIC (p=0.037) and BD (p=0.041) in the defect area (-D). NBH and BM-D differences within the groups were not significant (p>0.05). Significant more NFB was measured in the healthy control group (p=0.046). In the region of local bone BIC-L was significant less in the diabetic group (p=0.028). In the local control region BD-L and BM-L was lower in the diabetic group compared to the healthy control animals (p>0.05).
Conclusion
Histological evidence indicates impaired peri-implant defect regeneration in a diabetic animal model.
Link to Article
http://dx.doi.org/10.1016/j.jcms.2016.04.002
Three dimensional printed macroporous polylactic acid/hydroxyapatite composite scaffolds for promoting bone formation in a critical-size rat calvarial defect model
Authors
Haifeng Zhang, Xiyuan Mao, Zijing Du, Wenbo Jiang, Xiuguo Han, Danyang Zhao, Dong Han & Qingfeng Li
Abstract
We have explored the applicability of printed scaffold by comparing osteogenic ability and biodegradation property of three resorbable biomaterials. A polylactic acid/hydroxyapatite (PLA/HA) composite with a pore size of 500 μm and 60% porosity was fabricated by three-dimensional printing.3D printed PLA/HA,
β-tricalcium phosphate (β-TCP) and partially demineralized bone matrix (DBM) seeded with bone marrow stromal cells (BMSCs) were evaluated by cell adhesion, proliferation, alkaline phosphatase activity and osteogenic gene expression of osteopontin (OPN) and collagen type I (COL-1).Moreover, the biocompatibility,
bone repairing capacity and degradation in three different bone substitute materials were estimated using a critical-size rat calvarial defect model in vivo. The defects were evaluated by micro-computed tomography and histological analysis at 4 and 8weeks after surgery, respectively. The results showed that each of the studied scaffolds own its specific merits and drawbacks. 3D printed PLA/HA scaffolds possessed good biocompatibility and stimulated BMSCs cell proliferation and differentiation to osteogenic cells. And the outcomes in vivo revealed that 3D printed PLA/HA scaffolds had good osteogenic capability and biodegradation activity with no difference inflammation reaction. Therefore, 3D printed PLA/HA scaffolds have the potential applications in bone tissue engineering and may be used as graft substitutes in reconstructive surgery
Link to Article
http://www.tandfonline.com/doi/pdf/10.1080/14686996.2016.1145532
A novel nano-copper-bearing stainless steel with reduced Cu2+ release only inducing transient foreign body reaction via affecting the activity of NF-κB and Caspase 3
Authors
Lei Wang, Ling Ren, Tingting Tang, Kerong Dai, Ke Yang, Yongqiang Hao
Abstract
Abstract: Foreign body reaction induced by biomaterials is a serious problem in clinical applications. Although 317L-Cu stainless steel (317L-Cu SS) is a new type of implant material with antibacterial ability and osteogenic property, the foreign body reaction level still needs to be assessed due to its Cu2+ releasing property. For this purpose, two macrophage cell lines were selected to detect cellular proliferation, apoptosis, mobility, and the secretions of inflammatory cytokines with the influence of 317L-Cu SS. Our results indicated that 317L-Cu SS had no obvious effect on the proliferation and apoptosis of macrophages; however, it significantly increased cellular migration and TNF-α secretion. Then, C57 mice were used to assess foreign body reaction induced by 317L-Cu SS. We observed significantly enhanced recruitment of inflammatory cells (primarily macrophages) with increased TNF-α secretion and apoptosis level in tissues around the materials in the early stage of implantation. With tissue healing, both inflammation and apoptosis significantly decreased. Further, we discovered that NF-κB pathway and Caspase 3 played important roles in 317L-Cu SS induced inflammation and apoptosis. We concluded that 317L-Cu SS could briefly promote the inflammation and apoptosis of surrounding tissues by regulating the activity of NF-κB pathway and Caspase 3. All these discoveries demonstrated that 317L-Cu SS has a great potential for clinical application.