Polyurethane (PUR) and polyurethane/poly(d, l-lactide) acid (PUR/PDLLA) based scaffolds coated with Bioglass® particles for application in bone tissue engineering were fabricated. The slurry-dipping method was used for coating preparation. The homogeneous structure of the Bioglass® coatings on the surface of the PUR and PUR/PDLLA foams indicated a good adhesion of the bioactive glass particles to polyurethane without any additional surface treatment. In vitro studies in simulated body fluid (SBF) were performed to study the influence of Bioglass® coating on biodegrability and bioactivity of PUR-based scaffolds. The surface of Bioglass®-coated samples was covered by a layer of carbonate-containing apatite after 7 days of immersion in SBF, while in uncoated polymer samples apatite crystals were not detected even after 21 days of immersion in SBF. The apatite layer was characterized by scanning electron microscopy (SEM), EDS analysis and attenuated total reflectance–Fourier transform infrared spectrometry (FTIR–ATR). Weight loss measurements showed that the in vitro degradation rate of the composite scaffolds in SBF was higher in comparison to uncoated polyurethane samples. PUR and PUR/PDLLA foams with Bioglass® coating have potential to be used as bioactive, biodegradable scaffolds in bone tissue engineering.
There are two different concepts behind Unicompartmental Knee Replacement (UKR). Mobile bearings, as exemplified by the Oxford UKR, and fixed bearings, as exemplified by the Physica ZUK. These are the two most commonly implanted UKRs in the UK. For the first time, a comparison of the tribological features of 19 explanted Oxford and 19 explanted Physica ZUK UKRs was undertaken. Surface damage on the polyethylene (PE) inserts of the Oxford and Physica ZUK cohorts were assessed using an established semi-quantitative scoring method. The femoral components of both cohorts were assessed using a non-contact 3D profilometer to measure roughness values. It was found that the PE inserts of the Oxford cohort (22.54 ± 9.14) had statistically significant greater damage scores than the Physica ZUK cohort (16.50 ± 5.17) (p = 0.04). However, the femoral components of the Oxford cohort showed lower roughness values than the Physica ZUK cohort (p = 0.00). This is the first study that reports a comparative roughness analysis between retrieved Oxford and Physica ZUK UKR designs.
INTRODUCTION The design of a composite material like Polymethylmethacrylate bone cement loaded with a bioactive and ferrimagnetic glass-ceramic is very useful against the development and proliferation of bone tumors. The biomaterial can be used in hyperthermia treatment that produces heat by hysteresis loss due to magnetic phase of the glass-ceramic[1]. The aim of the present work is the synthesis and characterization of a composite material in which the disperse phase is a glass ceramic (SC45) with magnetic property, embedded polymeric bone cement. EXPERIMENTAL METHODS The SC45 powders,(see [1] for the chemical composition) sieved below 20 micron, were mixed in different amounts (10, 15, 20% wt) with the polymeric solid phase of a commercial bone cement (Palamed®MV). The mixed powders and the liquid monomer of the bone cements were mixed manually for two minutes and after that put inside a mold, obtaining the composite cements. P10, P15, P20 and plain cement (as control) samples have been prepared. The characterizations were developed for all formulations proposed as described below. Mechanical testing of cement samples The compressive strength of the cement were evaluated according to standard ISO 5833 procedure. For each formulation 6 samples were tested. Calorimetric measurements The heat generation was measured with induction furnace at fixed frequency and alternate electromagnetic field. The samples were placed in a test tube with 10 ml of distilled water. The increase of temperature that occurred following the heat transfer from the magnetic phase of the composite to water, was measured with a thermocouple. SEM and EDS analysis before and after bioactivity test Scanning electron microscopy had been implemented to analyze the morphology and composition of the samples. RESULTS AND DISCUSSION The compression strength of the composites depends from the amount of glass-ceramic phase; nevertheless the reached values satisfy the ISO requirements ( >70 MPa). Calorimetric tests show an maximum increasing temperature of 40°C that respect the limit imposed by hyperthermia therapy. By soaking of the samples in SBF for 28 day the growth of hydroxyapatite was observed. CONCLUSION The preliminary experimental tests demonstrated a good mechanical properties and a good osteointegration. The calorimetric test evidenced a range of temperature adapted to biological environment. REFERENCES 1. O. Bretcanu et al. Journal of Magnetism and Magnetic Materials, 305 (2006) 529-533. ACKNOWLEDGMENTS The authors would like to thank to the MIUR Grant for Young researchers
Polymethyl methacrylate (PMMA) bone cement with the addition of magnetic glass-ceramic (MGC) has attracted much attention for the treatment of deep-seated tumour tissues. Since PMMA bone cement has been a gold standard in orthopaedic surgery and magnetic glass-ceramic can generate heat under a magnetic field, the combination of these two materials could show promising results for magnetic induction hyperthermia treatment. Thus, magnetic glass-ceramic powders were mixed with the commercial Palacos MV® cement in amounts up to 40 wt%. The resulted magnetic bone cement composites were assessed in vitro for bioactivity and cytocompatibility. In vitro bioactivity was evaluated using a simulated body fluid (SBF). The effect of magnetic cement composition on the viability of cancerous and normal (non-cancerous) cells was assessed using U2OS osteosarcoma and OBS human osteoblast cells, respectively. Cell attachment to the surface of the magnetic composite samples was observed using fluorescence and scanning electron microscopy. The magnetic composites showed bioactive properties. After two weeks of immersion in SBF, a non-uniform layer of hydroxyapatite was observed on their surface. Alamar blue cytotoxicity tests after 3 days in cell culture indicated that magnetic composites are cytotoxic for U2OS cancer cells, but they are cytocompatible to OBS normal cells.
The Back Cover picture shows the structure of a reduced graphene oxide (rGO)/Bi composite material synthesized through a simple and scalable procedure. The material shows both supercapacitor and battery behavior (supercapattery behavior) and achieves a specific capacity value close to its theoretical value while atmospheric oxidation of metallic bismuth is inhibited by the reduced graphene oxide. More details can be found in the Full Paper by Wang et al. on page 363 in Issue 2, 2017 (DOI: 10.1002/cssc.201601553).
Aims: The purpose of this work is the preparation and characterisation of bioactive ferrimagnetic biomaterials. These materials can form a stable bond to the bone and can be heated by the application of an external alternating magnetic field, so they are good candidates for non-invasive hyperthermic treatment of solid bone tumours. Methods: The investigated materials are glass-ceramics belonging to the system SiO2-CaO-Na2O-P2O5-FeO-Fe2O3. They can be obtained by different methods, such as melting of traditional raw materials (oxides, carbonates or phosphates), thermal treatment of wet-chemistry derived precursors, or sintering. In the first two methods, different amounts of magnetite can crystallize inside the amorphous phase during cooling from the processing temperature to r.c., leading to a glass-ceramic. In the sintering method, glass powders and magnetite particles are intimately mixed and successively thermally treated, so that a composite material is obtained. A complete characterization was performed in terms of morphology and microstructure (SEM, TEM, XRD, DTA), bioactivity (soaking in SBF), magnetic properties (hysteresis loss) and calorimetric measurements (specific power loss). Results: Depending on the synthesis process it is possible to obtain both dense and macroporous devices (glass-ceramic or composites up to some centimeters size) as well as glass-ceramic micrometric particles. The magnetite crystals inside the amorphous phase are nanometric or submicrometric, depending on the synthesis method. The glass-ceramics have a bioactive behaviour, since hydroxyapatite grows on their surface after few days of soaking in Simulated Body Fluid. The hysteresis loss and the specific power loss are compatible with the temperature required for hyperthermic treatments of neoplastic tissues. Conclusions: Innovative magnetic biomaterials have been designed and synthesized by a careful optimization of the composition and processing parameters. Different synthesis methods can be used to prepare these biomaterials, in function of the tissue characteristics and magnetic field conditions. Due to the possibility of producing very small devices, these materials can be implanted by non-invasive surgical techniques, and since they are bio-compatible, can be let inside the body for a long period, being subjected to multiple heating cycles. Due to their bioactivity they could be proposed as an alternative for the treatment of bone tumors after surgical resection
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