1,721,083 research outputs found
Bioactive magnetic glass–ceramics for cancer treatment
No full textBioactive glasses and glass–ceramics are traditionally applied for bone regeneration due to their well-known ability to bind to bone tissue and promote its repair. Recently, their therapeutic potential has been extended to other applications, including the treatment of tumors. In fact, bioactive glasses can be functionalized with chemotherapy drugs and their composition can be tailored by introducing elements or phases useful for the treatment of tumors through hyperthermia. This chapter provides guidance on the use of magnetic hyperthermia and illustrates a broad overview of the magnetic and bioactive glasses and glass–ceramics investigated for the treatment of tumors, especially bone tumor, exploring the modulation of their composition and the different synthesis methods. Furthermore, this chapter presents the recent advances in tumor and its complication treatments through the use of innovative and multifunctional ceramic materials, thus opening new opportunities for targeted and effective tumor therapy
Ferrimagnetic devitrified glass doped with copper by ion exchange: Microstructure, bioactivity and antibacterial properties
Full text linkIn this work, the ion-exchange technique in molten salts was investigated to introduce copper ions in a bioactive and ferrimagnetic devitrified glass. This approach aimed to develop a magnetic and bioactive material for oncologic bone implants, able to join the ability to promote bone bonding to hyperthermic therapy while simultaneously lowering the risk of developing post-surgery infections. The ion-exchange approach was developed in order to overcome experimental critical issues related to the influence of copper introduction as a starting reagent, during the material synthesis, on magnetite nucleation.
The magnetic devitrified glass was prepared by melt and quenching route, followed by ion exchange in a mixture of molten sodium and copper nitrates, in three different Na/Cu molar ratios (20, 200, 2000). The obtained samples were analysed in terms of morphology, composition, ability to release heat, bioactivity and antibacterial properties. The results revealed that copper ion-exchange involved both sodium and calcium ions and the precipitation of few amounts of copper oxide aggregates occurred. The crystalline nature of the starting material and its ability to reach the temperature needed for hyperthermia, under exposition to an alternating magnetic field, were not affected. A bacteriostatic effect was obtained by samples with the highest copper amount and the copper doping did not affect the bioactivity of the glass ceramic
Bioactive and antibacterial glass particles as fillers in composite bone cements: Influence of amount and size on radio-opacity, bioactivity, mechanical and antibacterial properties
No full textIn this work, a bioactive and antibacterial glass has been added to a commercial PMMA-based bone cement to promote osteointegration and simultaneously limit bacterial contamination. The influence of the amount and size of glass powders on mechanical properties, radio-opacity, bioactivity and antibacterial effect of the composite cements has been estimated. The obtained results suggested that both filler's amount and size can affect the bending strength of the samples. The composites radio-opacity can be modulated by varying the amounts of glass and radio-opaque agent usually present in the commercial composition. The bioactive and antibacterial properties evaluation evidenced that introducing 10 wt.% of glass conferred a bioactive behaviour to the PMMA-based matrix and limited the bacterial contamination. Finally, an approach to technological transfer with controlled process parameters has been proposed
Synthesis and characterization of sol-gel bioactive glass nanoparticles doped with boron and copper
Full text linkIn this work the sol-gel synthesis of bioactive glass nanoparticles containing both boron and copper oxides is reported for the first time in the literature. Two acid/base co-catalysed methods were compared. The obtained glasses have been characterized in terms of morphology, composition, particle surface area, phase analysis and bioactivity in acellular simulated body fluids. The almost spherical nanoparticles (<100 nm diameter) obtained are characterized by a certain degree of aggregation and have compositions, which are coherent with the theoretical ones. Each glass revealed the ability to promote the growth of hydroxyapatite on its surface during soaking in simulated body fluid, thus we can assume that the addition of boron and copper did not negatively affect the bioactivity of the sol-gel derived glasses. Future investigations will be devoted to biological characterizations for cytotoxicity, antibacterial properties and pro-angiogenetic abilities
Tailoring of bioactive glass and glass-ceramics properties for in vitro and in vivo response optimization: a review
Full text linkBioactive glasses are inorganic biocompatible materials that can find applications in many biomedical fields. The main application is bone and dental tissue engineering. However, some applications in contact with soft tissues are emerging. It is well known that both bulk (such as composition) and surface properties (such as morphology and wettability) of an implanted material influence the response of cells in contact with the implant. This review aims to elucidate and compare the main strategies that are employed to modulate cell behavior in contact with bioactive glasses. The first part of this review is focused on the doping of bioactive glasses with ions and drugs, which can be incorporated into the bioceramic to impart several therapeutic properties, such as osteogenic, proangiogenic, or/and antibacterial ones. The second part of this review is devoted to the chemical functionalization of bioactive glasses using drugs, extra-cellular matrix proteins, vitamins, and polyphenols. In the third and final part, the physical modifications of the surfaces of bioactive glasses are reviewed. Both top-down (removing materials from the surface, for example using laser treatment and etching strategies) and bottom-up (depositing materials on the surface, for example through the deposition of coatings) strategies are discussed
Interfacial Structures Associated with Surface Activity in Magnetic Devitrified Glasses for Biomedical Applications
Full text linkIn bioactive magnetic devitrified glasses, the amorphous region with a porous structure is reduced compared to that in relevant glasses due to the formation of crystalline phases, such as magnetite crystals, which deteriorate the bioactive properties that arise from the active surface area. In this study, the local atomic structure associated with surface activity was investigated as an alternative to the reduced amorphous region in bioactive ferrimagnetic devitrified glasses doped with Cu via melt-quenching and ion exchange. Element-specific positron annihilation spectroscopy revealed that the melt-quenching approach effectively introduces Cu ions into the boundaries among magnetite-based crystals, forming void-like open spaces. The interior surfaces of these void-like open spaces within the crystal boundaries act as active areas, as evidenced by the formation of carbonate species through the reaction of Ca with CO2 in the air. The results confirm that Cu ions introduced into the crystal boundaries play an important role not only in imparting antibacterial properties but also in developing locally active surfaces
Angiogenesis induction by bioactive glasses and glass-ceramics
No full textBioactive glasses (BGs) have an outstanding place in tissue engineering and regenerative medicine strategies. These synthetic materials were historically used for the treatment of bone and dental tissues; recent studies have proved their effectiveness in managing soft tissue injuries as well. BGs exhibit several biological properties in favor of tissue healing, including the ability to attach to tissues and promoting cell growth, proliferation, and differentiation. The release of therapeutic ions from BG structure into the surrounding environment is commonly regarded as the main mechanism associated with their biological properties. The ability to induce new blood vessel formation (i.e., angiogenesis) is among the most interesting characteristics of BGs, which may be beneficial for accelerating tissue wound healing. This capacity can be easily improved by adding specific concentrations of angiogenesis-inducing elements (e.g., copper and cobalt) to the basic formulation of BGs. All categories of BGs, including silicate-, phosphate-, and borate-based glasses, were evaluated and successfully doped with proangiogenic elements. In addition, BGs are known as suitable platforms for loading and delivery of a wide range of proangiogenic bioactive molecules like growth factors, cytokines, and chemokines. Utilizing BGs in three-dimensional (3D) scaffolds may be considered for the next generation of proangiogenic bone tissue substitutes
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