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Purpose: The aim of the presented work was to characterize the new obtained bioglasses and assess their biological performance in vitro. Bioglasses were produced using the sol-gel method in the SiO2-P2O5-CaO system, for the purpose as composite ingredients. Their chemical composition was enriched with ZnO to introduce antibacterial properties and SrO with osteoinductive effect. The properties of bioglasses were compared and the effect of chemical composition and particle size on their biological properties was assessed. Methods: The bioglasses were evaluated via TG-DTA, FTIR, SEM-EDS analyses before and after incubation in SBF solution. LDH and WST-1 tests were used to determine the level of cytotoxicity of the tested bioglasses on hFOB1.19 osteoblasts. Results: The results show that the developed bioglasses release Ca2+, are bioactive in SBF solution, not cytotoxic and show antibacterial activity in contact with Pseudomonas aeruginosa and Staphylococcus aureus strains. Bioglasses enriched with ZnO show the highest bactericidal activity. All tested bioglasses enhanced hFOB 1.19 cells proliferation. Particle size has a lower effect on biological performance of the bioglasses than their chemical composition. Conclusions: The conducted research showed that bioglass modification with SrO and ZnO can be considered particularly for the development of biomaterials supporting bone regeneration and the treatment of infected bone defects. [ABSTRACT FROM AUTHOR]

In calcite and aragonite, γ-irradiated at 77 K, several paramagnetic centers were generated and detected by EPR spectroscopy; in calcite, CO3− (orthorhombic symmetry, bulk and bonded to surface), CO33−, NO32−, O3−, and in aragonite CO2− (isotropic and orthorhombic symmetry) depending on the type of calcium carbonate used. For calcium carbonates enriched with 13C more detailed information about the formed radicals was possible to be obtained. In both natural (white coral) and synthetic aragonite the same radicals were identified with main differences in the properties of CO2− radicals. An application of Q-band EPR allowed to avoid the signals overlap giving the characteristics of radical anisotropy.

The research aimed at the selection of polyurethanes synthesized from poly(tetramethylene ether) glycol (PTMEG), as well as from two different isocyanates 4,4′-methylenebis(cyclohexyl)isocyanate (HMDI) and 4.4′-methylenebis(phenyl isocyanate) (MDI) in order to obtain polyurethane with increased resistance to abrasive wear and degradation for bio-medical application. Polyurethanes were fabricated from crystalline prepolymers extended by water. The paper presents preliminary results on polyurethane surface wettability, friction coefficient for different couples of the co-working materials such as polyurethane-polyurethane, polyurethane-titanium alloy, polyurethane-alumina, in comparison to commonly used polyethylene-titanium alloy. Shear strength of polyurethane-alumina joint, as well as viscosity of prepolymers were also measured. The values of friction coefficient were compared to literature data on commercially available polyurethane with the trade name Pellethane. Polyurethanes obtained are characterized by low abrasive wear and low friction coefficient in couple with the titanium alloy, what makes them attractive as possible components of ceramic-polymer endoprosthesis joints.

Chitosan is one of the most commonly employed natural polymers for biomedical applications. However, in order to obtain stable chitosan biomaterials with appropriate strength properties, it is necessary to subject it to crosslinking or stabilization. Composites based on chitosan and bioglass were prepared using the lyophilization method. In the experimental design, six different methods were used to obtain stable, porous chitosan/bioglass biocomposite materials. This study compared the crosslinking/stabilization of chitosan/bioglass composites with ethanol, thermal dehydration, sodium tripolyphosphate, vanillin, genipin, and sodium β-glycerophosphate. The physicochemical, mechanical, and biological properties of the obtained materials were compared. The results showed that all the selected crosslinking methods allow the production of stable, non-cytotoxic porous composites of chitosan/bioglass. The composite with genipin stood out with the best of the compared properties, taking into account biological and mechanical characteristics. The composite stabilized with ethanol is distinct in terms of its thermal properties and swelling stability, and it also promotes cell proliferation. Regarding the specific surface area, the highest value exposes the composite stabilized by the thermal dehydration method. [ABSTRACT FROM AUTHOR]

The paper presents preliminary results of the implantation of calcium sulfate type Hartform HF1 developed at the Institute of Glass and Ceramics in Warsaw. The study was conducted on 10 New Zealand White rabbits, in which after tibial osteotomy the biomaterial was implanted directly into the fracture site. The animals were divided into two groups based on the method of fracture stabilisation: intramedullary pinning using Kirschner wires in one group and acrylic external fixator in the other. After 12 weeks, bone union was observed in all animals as estimated by clinical and radiological findings. Histological tests revealed resorption of the biomaterial into the bone fracture area. It was concluded that type Hartform 1 calcium sulfate can be used as a biomaterial in veterinary orthopedics. Due to the lack of observable side effects during implantation and resorption, the material can be considered as a valuable ingredient in composite biomaterials containing calcium sulfate.

The article presents the results of in vitro studies on cytotoxicity and antibacterial activity of new MTA-type cements, developed on the basis of the sintered tricalcium silicate enriched with ZnO, along with an agent introducing the radiopacity in the form of ZrO2. The new materials have been developed to ensure that their physical and chemical properties are suited for endodontic applications. The cements were evaluated via characterisation of setting time, compressive strength, as well as translucency on X-ray images, and bioactivity in the simulated body fluid (SBF). The μCT was used to test the influence of the ZrO2 grains in the powder component on the microstructure of the produced cement. Then, the cytotoxic action of the cements was evaluated by applying a reference L-929 cell line. The conditions of the culture upon contact with the tested materials or with extracts from the cements were assessed using image analysis or an MTT colorimetric assay. Two strains of streptococci, Streptococcus mutans and Streptococcus sanguinis, were used to study the antibacterial activity of the tested cements with ZrO2 acting as the agent introducing the radiopacity. The new cements are characterised by appropriate properties as far as retrograde root canal filling is concerned. [ABSTRACT FROM AUTHOR]

The article presents the results of in vitro studies on cytotoxicity and antibacterial activity of new MTA-type cements, developed on the basis of the sintered tricalcium silicate enriched with ZnO, along with an agent introducing the radiopacity in the form of ZrO2. The new materials have been developed to ensure that their physical and chemical properties are suited for endodontic applications. The cements were evaluated via characterisation of setting time, compressive strength, as well as translucency on X-ray images, and bioactivity in the simulated body fluid (SBF). The μCT was used to test the influence of the ZrO2 grains in the powder component on the microstructure of the produced cement. Then, the cytotoxic action of the cements was evaluated by applying a reference L-929 cell line. The conditions of the culture upon contact with the tested materials or with extracts from the cements were assessed using image analysis or an MTT colorimetric assay. Two strains of streptococci, Streptococcus mutans and Streptococcus sanguinis, were used to study the antibacterial activity of the tested cements with ZrO2 acting as the agent introducing the radiopacity. The new cements are characterised by appropriate properties as far as retrograde root canal filling is concerned. [ABSTRACT FROM AUTHOR]

The paper presents results of the studies on porous composites obtained using lyophilization method based on the solutions of the following polymers: chitosan, sodium alginate and polylactide, as well as ZnO‐doped CaO–SiO2–P2O5 bioglass. The researchers took the advantage of zinc ions demonstrating the bactericidal, immune‐stimulating, and tissue‐regenerating functions in the organism. The cytotoxicity of the composites was tested on L929 cells by means of the direct and the indirect contact method. The antibacterial properties were determined against the gram‐negative bacteria Pseudomonas aeruginosa and the gram‐positive bacteria Staphylococcus aureus at 24, 48 hours, and 7 days. The study demonstrated that changes due to cytotoxicity effect of the composites depend on the type of polymer and on the duration of contact with cells. The composite with polylactide was found to be the least toxic for L929 cells. ZnO added to the chemical composition of bioglass ensured bactericidal effects. The antibacterial properties of the composites depended on the ZnO content, bioglass grain size, polymer type, and composite microstructure. The composites presented in this paper are innovative as biomaterials for filling bone cavities because they can be a matrix for cells and have an antibacterial effect while supporting the regeneration of damaged tissue. [ABSTRACT FROM AUTHOR]

In calcite and aragonite, γ-irradiated at 77 K, several paramagnetic centers were generated and detected by EPR spectroscopy; in calcite, CO3− (orthorhombic symmetry, bulk and bonded to surface), CO33−, NO32−, O3−, and in aragonite CO2− (isotropic and orthorhombic symmetry) depending on the type of calcium carbonate used. For calcium carbonates enriched with 13C more detailed information about the formed radicals was possible to be obtained. In both natural (white coral) and synthetic aragonite the same radicals were identified with main differences in the properties of CO2− radicals. An application of Q-band EPR allowed to avoid the signals overlap giving the characteristics of radical anisotropy. [ABSTRACT FROM AUTHOR]

Purpose : The aim of the presented work was to characterize the new obtained bioglasses and assess their biological performance in vitro . Bioglasses were produced using the sol-gel method in the SiO 2 -P 2 O 5 -CaO system, for the purpose as composite ingredients. Their chemical composition was enriched with ZnO to introduce antibacterial properties and SrO with osteoinductive effect. The properties of bioglasses were compared and the effect of chemical composition and particle size on their biological properties was assessed. Methods : The bioglasses were evaluated via TG-DTA, FTIR, SEM-EDS analyses before and after incubation in SBF solution. LDH and WST-1 tests were used to determine the level of cytotoxicity of the tested bioglasses on hFOB1.19 osteoblasts. Results : The results show that the developed bioglasses release Ca 2+ , are bioactive in SBF solution, not cytotoxic and show antibacterial activity in contact with Pseudomonas aeruginosa and Staphylococcus aureus strains. Bioglasses enriched with ZnO show the highest bactericidal activity. All tested bioglasses enhanced hFOB 1.19 cells proliferation. Particle size has a lower effect on biological performance of the bioglasses than their chemical composition. Conclusions : The conducted research showed that bioglass modification with SrO and ZnO can be considered particularly for the development of biomaterials supporting bone regeneration and the treatment of infected bone defects., (© 2023 Lidia Ciołek et al., published by Sciendo.)

Aim of the Study: Evaluation of the influence of the introduced structure modification in porous ceramic grafts on TiO2 base on overgrowing with bone tissue, in examinations with use of scanning microscopy and X-rays was the subject of the examinations., Material and Method: New ceramic materials based on TiO2 with high values of mechanical resistance, large sintering degree and biocompatibility in in vitro conditions were prepared. Those properties cause that they are worth interest as potential osteosubstitutive materials. Two kinds of grafts were created from ceramics based on TiO2: with compact and porous structure. The introduced structure modification - macroporosity - had the purpose to give osteoconductive properties to the grafts, to evoke processes favorable for bone tissue forming. In examinations of the local reaction of bone tissue after implantation of the formed porous grafts, degree of their osteointegration, the essential issue is the evaluation of the settling of the inner spaces with supporting tissues. Samples of the tested compact and porous materials in the form of cylinders were implanted in femoral bones of rabbits for a period till 6 months. The surfaces of grafts and the degree of their settling with supporting tissues were evaluated in cross-sections of the implants with light and scanning microscopic methods and they were confirmed in X-ray tests., Results: Analysis of the obtained data showed that, the surface of solid ceramic on TiO2 base was covered mainly with increasing with a time of observation quantities of extracellular substance and lamellas of bone. The macrporous structure of porous ceramic on TiO2 base enabled settling of the inner spaces of graft with supporting tissue cells, partly in the 1st month, more intensively in the 3rd and it was not completed in the 6th month after implantation., Conclusions: Porous grafts in the form of ceramic foam on TiO2 base showed osteoconductive properties, though process of colonization after 6th month observation was not completed and the condition of the cells inside of the implant was reduced.