1,720,985 research outputs found
BONE GRAFT SUBSTITUTES IN MAXILLO-FACIAL SURGERY
Full text linkBiomaterials for reconstruction of bony defects of the skull comprise of osteosynthetic materials applied after osteotomies or traumatic fractures and materials to fill bony defects which result from malformation, trauma or tumour resections. Other applications concern functional augmentations for dental implants or aesthetic augmentations in the facial region. The wide range of biomaterials available on the market, together with lack of established criteria to guide the use of a specific biomaterial in a particular application, has resulted in different surgeons using different materials, with no uniformity in clinical application. The optimal biomaterial that meets every requirement (e.g. biocompatibility, stability, intraoperative fitting, product safety, low costs etc.) does not exist. The different material types are (autogenic) bone and many alloplastics such as metals, ceramics, plastics and composites. We discuss our clinical experience in the use of biomaterials for craniofacial application and we present our experience with some experimental laboratory studies . Based on literature review, we present guidelines for use of different biomaterials in maxillo-facial surgery
In-vivo short- and long-term evaluation of the interaction material-blood.
No full textThrough an innovative electron microscopy technique, thrombi and fibrotic tissue taken from 14 explanted vena cava filters were observed. Twelve cases showed the presence of micro-and nano-sized inorganic, non biodegradable nor biocompatible particles which did not belong to the metal the device was made of and which could be the sole cause or, more likely, a pre-existing cause for thrombosis. In two cases, those debris activated immunological reactions typical of a foreign body. The presence of inorganic particles in the blood was never detected before and their effects on human health are hardly known. Their thrombogenicity should be added to the Virchow's Triad as a fourth factor and could be the explanation to many of the cases of pulmonary embolism where no thrombotic focus could be demonstrated
SBF assays, direct and indirect cell culture tests to evaluate the biological performance of bioglasses and bioglass-based composites: Three paradigmatic cases
No full textA novel bioglass composition (BGMS10), containing strontium and magnesium and characterized by an ultra-high crystallization temperature, is here employed for the first time to produce different composites with the addition of specific amounts of hydroxyapatite. After an investigation of the samples’ bioactivity in vitro in a simulated body fluid solution (SBF) – according to a widely used protocol – the biocompatibility of the new materials was tested with respect to murine fibroblasts both by direct and indirect tests, in order to evaluate possible cytotoxic effects of the materials’ eluates. Although none of the samples were cytotoxic and their bioactivity in SBF increased with the increasing amount of the glass in the composite, thus showing the best performance in the case of pure BGMS10 glass, the findings of the biological investigation did not confirm those arising from the SBF assay. Surprisingly, while the composites with the lowest glass amount showed an enhanced biocompatibility in direct tests, on the contrary their biological responsiveness is typically lower in the indirect ones, based on filtered materials’ extracts. This fact could be ascribed to the high release of particulate from the composites, which are more porous than the glassy samples: in fact, such pronounced dissolution may affect both the cell viability and the absorbance readings used in the colorimetric assays. The pure BGMS10 glass showed the best biological response only in the cell proliferation test (which is an indirect contact test), being able to stimulate cell proliferation in particular after 24 h. For these reasons, when considering bioactive glasses and bioglass-based composites, the results of direct cell culture assays should be integrated with those obtained by indirect ones, while the findings regarding the in vitro bioactivity in SBF should be interpreted with great care
Cytocompatibility of mesoporous bioactive glasses doped with cerium and loaded with polyphenols
No full textTherapeutic inorganic ions (TIIs) and biomolecules like polyphenols (POLY) can both enhance the properties of mesoporous bioactive glasses (MBGs), which are promising biomaterials for use in hard and soft tissues. In our previous studies, we demonstrated the excellent antioxidant properties of cerium-doped MBGs containing polyphenols (Ce-MBGs-POLY) and their persistent apatite-forming ability. Therefore, the aim of this study is to evaluate the cytocompatibility of MBGs containing POLY and/or cerium. The cytocompatibility is evaluated using MLO-Y4 cells, Neutral Red (NR) and the 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assays, and morphological analyses. The NR and MTT results show that MBG-POLY and Ce-MBG-POLY improve cell viability and proliferation compared with MBG, indicating the beneficial effects of both cerium and polyphenols on cell health. Morphological evaluations using optical and electron microscopes confirmed good cell adhesion and proliferation on the surface of all studied MBGs. MBG-POLY and Ce-MBG-POLY possess not only antioxidant properties and apatite-forming ability but are also cytocompatible; for this reason, these MBGs may be proposed as innovative materials to promote tissue regeneration and repair
Could the periodontal therapy improve the cardiologic patient health? A narrative review
Full text linkBackground: Cardiovascular diseases (CVD) is the major cause of mortality globally, with increasing evidence suggesting a link between periodontitis, and CVD. This study aims to explore the association between periodontitis and CVD, and the impact of periodontal therapy on cardiovascular health. Methods: This review synthesized findings from preclinical and clinical studies, without publication year restrictions, examining periodontitis and CVD through various lenses. Scientific databases were inspected with keywords related to periodontitis and CVD. Results: The review identifies a substantial association between periodontitis and an increased risk of several CVD, supported by both epidemiological and interventional studies. Results suggest the complexity of the relationship, influenced by factors like the severity of periodontitis and the presence of other systemic conditions. Clinical data indicates that periodontal therapy, particularly non-surgical periodontal therapy, may reduce systemic inflammatory markers and thus may play a role in the primary and secondary prevention of CVD events, highlighting the potential of periodontal therapy to not only maintain oral health but also to modulate cardiovascular risk factors. Conclusions: Current evidence supports a significant association between periodontitis and increased cardiovascular risk, promoting integrated healthcare approaches that consider oral health as a key-component of cardiovascular care and wellbeing
Chitosan-Based Bioactive Glass Gauze: Microstructural Properties, In Vitro Bioactivity, and Biological Tests
Full text linkPassive commercial gauzes were turned into interactive wound dressings by impregnating them with a chitosan suspension. To further improve healing, and cell adhesion and proliferation, chitosan/bioactive glass wound dressings were produced with the addition of (i) 45S5, (ii) a Sr- and Mg-containing bioactive glass, and (iii) a Zn-containing bioactive glass to the chitosan suspension. SEM and FTIR analyses evidenced positive results in terms of incorporation of bioactive glass particles. Bioactivity was investigated by soaking chitosan-based bioactive glass wound dressings in simulated body fluid (SBF). Cell viability, proliferation, and morphology were investigated using NIH 3T3 (mouse embryonic fibroblast) cells by neutral red (NR) uptake and MTT assays. Furthermore, the wound-healing rate was evaluated by means of the scratch test, using NIH 3T3. The results showed that bioactive glass particles enhance cell adhesion and proliferation, and wound healing compared to pure chitosan. Therefore, chitosan-based bioactive glass wound dressings combine the properties of the organic matrix with the specific biological characteristics of bioactive glasses to achieve chitosan composites suitable for healing devices
A Novel Bioactive Glass Containing Therapeutic Ions with Enhanced Biocompatibility
Full text linkA novel bioactive glass containing therapeutic ions with enhanced biocompatibility was designed and produced by the classical melt-quenching route. Starting from a very promising composition (Bio_MS), which combined bioactivity and high crystallization temperature, the ratio between some oxides was tailored to obtain a new and more reactive (in terms of dissolution rate) bioactive glass, called BGMSN (composition in mol%: 6.1 Na2O, 31.3 CaO, 5 MgO, 10 SrO, 2.6 P2O5, 45 SiO2). The aim of this work was to produce a bioactive glass with a good biological performance, preserving, at the same time, the high crystallization temperature achieved for Bio_MS; this is strategic in order to avoid undesired crystalline phases during thermal treatments, which can undermine the bioactivity and even the stability of final products. A complete characterization of the novel bioactive glass was performed in terms of thermal, mechanical and biological properties and in vitro bioactivity. The thermal behavior of the bioactive glass was studied by heating microscopy, differential thermal analysis (DTA) and optical dilatometry; BGMSN showed a very high crystallization temperature and a high sinterability parameter, thus being suitable for applications where thermal treatments are required, such as sintered samples, coatings and scaffolds. Mechanical properties were investigated by the micro-indentation technique. The in vitro biological properties were evaluated by means of both direct and indirect cell tests, i.e., neutral red (NR) uptake and MTT assay, using murine long bone osteocyte Y4 (MLO-Y4) cells: the cellular viability of BGMSN was higher compared to cellular viability of 45S5, both in direct and indirect tests. Finally, the in vitro bioactivity test by soaking samples in simulated body fluid (SBF) showed high dissolution rate, with a good rate of formation of hydroxyapatite
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