Local and Systemic Inflammation After Implantation of a Novel Iron Based Porous Degradable Bone Replacement Material in Sheep Model

Despite a high regenerative potential of healthy bone, replacement of large bone defects is an currently ongoing medical challenge. Due to a lack of mechanical stability of existing bone substitutes, recently developed degradable metallic alloys are an interesting alternative providing higher load bearing properties. Degradable iron-based alloys are an attractive innovation. Therefore, a degradable iron-based bone replacement material has been developed.To test the suitability of a newly designed iron-based alloy, an animal experiment was performed. Porous iron-based degradable implants with two different densities and a control group were tested. The implants were positioned in the proximal tibia. Over a period of 6 and 12 months, blood and histological parameters were monitored for signs of inflammation and degradation. Even if degradation at the desired rate was not achieved, in the histological evaluation of the implants` environment we found degraded particles, but no inflammatory reaction. Iron particles were also found within the popliteal lymph nodes on both sides. The serum blood levels of phosphorus, iron and ferritin in the long term groups were elevated. Other parameters did not show any changes.Iron-based degradable porous bone replacement implants showed a good biocompatibility in this experiment. For a clinical application, however, the rate of degradation would have to be significantly increased. Biocompatibility would then have to be re-evaluated.

The Porosity and Human Gingival Cells Attachment of Synthetic Coral Scaffold for Bone Regeneration

Porosity and interconnectivity play an important role in the success of tissue engineering because it affects cells to live and grow. Coral has been used as a bone replacement material because the structures resemble bone and have mechanical bone properties. In this study, the synthetic coral scaffold was developed to mimic the natural coral. This study aims to investigate the porosity of the scaffold and its biocompatibility while it is attached to human gingival cells. Synthetic coral scaffold in various compositions were prepared, porosity percentage measurement and human gingival cell attachment test were done. An optimum ratio of the scaffold with gelatin: CaCO3, having the highest porosity and cell attachment is obtained in 5:5. The result of this study presented that synthetic coral scaffold could provide the microenvironment to cells for life because it is supported by the highest percentage of porosity.

Effect of CaSO4 Dissolution-Precipitation Time on Formation of Porous Carbonate Apatite as Bone Replacement Material

Introduction: Carbonate apatite type B (C-Ap) has been used as a bone replacement material because of its osteoconductive properties. Clinically, the pores formed in bone replacement material aid in cell mobility and nutrient supply, thereby increasing the bone regeneration ability. CO32- ions found in this material are useful for maintaining a stable physiological environment in the bone in order for it to be easily absorbed by osteoclasts. Porous C-Ap type B is formed using the dissolution–precipitation method by immersing porous anhydrous CaSO4 in a mixture of carbonate and phosphate solutions. Purpose: The present study aimed to evaluate the effect of immersion ofCaSO4using the dissolution–precipitation method on the formation of porous C-Ap type B with calcium sulfate precursor hemihydrate. Method: Porous C-Ap type B was produced usinga mixture of calcium sulfate hemihydrate precursors with 50 wt% polymethylmethacrylate (PMMA) porogen and distilled water. After hardening, the calcium sulfate dihydrate containing PMMA was burned in an oven at 700°C for 4 h to remove the PMMA. The specimen was immersed in a mixture of sodium phosphate (Na3PO4) and sodium carbonate (Na2CO3) for 6, 12, and 24 h. Phase testing through X-ray diffraction (XRD) using CuKα radiation at 40 kV and 40 mA was performed. Attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR, Thermo Fisher Scientific, Waltham, Massachusetts, USA) was used for detecting the functional groups of CO32- and PO42-. Results: XRD results showed the formation of C-Ap at 6 and 12 h, but the anhydrous CaSO4 phase remained; alternatively, this phase was absent after 24 h of immersion phase andFTIR showed the presence of the functional groups of CO32- compounds. Conclusion: Porous C-Ap type B can be formed from CaSO4 precursors after 24 h of immersion using the dissolution–precipitation method.

Bioglass at 50 – A look at Larry Hench’s legacy and bioactive materials

In 1969, fifty years ago, a young professor of ceramic engineering created a 4-component glass to be used as a bone replacement material. That material became known as “Bioglass” and more generally as a class of materials known as bioactive glass. Those first experiments conducted by Dr. Larry Hench completely shifted the paradigm of how the biomaterials and medical communities look at the interactions between inorganic materials and tissues in the body. This article will touch on just a few highlights of the development of bioactive glasses and relate those to the concepts of bioactivity and tissue bonding.

Investigation on the Anticorrosion Property of the MnCaP Coating on a Mg-Zn-Ca Alloy

In order to improve the anticorrosion ability of a Mg-5Zn-1.5Ca alloy used as a bone replacement material, this study prepared the MnCaP conversion coating, which was formed from a phosphating solution mixed with a MnCl2 solution of 0.05 molarity, on a magnesium (Mg) alloy. After forming a MnCaP conversion coating on a Mg alloy, micro-arc oxidation (MAO) proceeded for improving the anticorrosion ability of the sample. As a result, when the 0.05MnCaP coating on a Mg alloy was immersed in the simulated body fluid (SBF), the corrosion current, pH value change, and hydrogen evolution volume of the SBF solution are lower than a uncoated Mg alloy. From the SEM and EDS analyses for a corroded 0.05MnCaP coating on a Mg alloy, the manganese (Mn) phosphate in a lumpy-rock form and the calcium (Ca) phosphate in a flake form alternate to each other densely, so that the coating can effectively prevent a Mg alloy from corrosion.