Full-text resources of PSJD and other databases are now available in the new Library of Science.
Visit https://bibliotekanauki.pl
Preferences help
enabled [disable] Abstract
Number of results

Results found: 5

Number of results on page
first rewind previous Page / 1 next fast forward last

Search results

Search:
in the keywords:  bioactive glass
help Sort By:

help Limit search:
first rewind previous Page / 1 next fast forward last
|
|
vol. 1
|
issue 1
EN
In this communication, hollow bioactive glass (BG) nanofibers were fabricated via a single-nozzle electrospinning method. The morphology of the prepared hollow BG nanofibers was observed by SEM and TEM, and the results showed that BG nanofibers had a continuous hollow interior. The hollow BG nanofibers were incubated in simulated body fluid (SBF) to investigate their apatitemineralization ability, and the result showed that after incubation for 6 h a flower-like apatite was observed on the surface of hollowBGnanofibers, and the Fourier transform infrared (FTIR) result further confirmed the formation of apatite. The results suggested that hollow BG nanofibers could be used for drug delivery and bone regeneration applications due to their unique hollow structure and bioactivity.
EN
To prevent the high frequency of wound infections, anti-bacterial agents can be loaded onto composites. In the present study, the antibiotic tetracycline hydrochloride (TC)was incorporated, for the first time, in collagen type I membranes coated with nano-sized SiO2-CaOP2O5 bioactive glass (n-BG) obtained by a sol-gel chemical route. Collagen membranes coated with n-BG were immersed in simulated body fluid (SBF) containing 0.25, 0.75 or 1.25 mg mL−1 of TC for 48 h at 37∘C following a coprecipitation method. The antibiotic was released in distilledwater at 37∘C for up to 72 h. The antibacterial activity of the composites was evaluated in vitro by the inhibition zone test and plate count method. Two different Staphylococcus aureus strains, S. aureus ATCC29213 and S. aureus ATCC25923, were exposed to the biomaterials. The results showed that the incorporation but not the release of TC was dependent on the initial concentration of TC in SBF. The biomaterials inhibited S. aureus growth, although the efficacy was similar for all the concentrations. The results allow us to conclude that the new composite could have potential in the prevention of wound infections.
EN
Bone regeneration is a process of vital importance since fractures of long bones and large joints have a highly deleterious impact on both, individuals and society. Numerous attempts have been undertaken to alleviate this severe medical and social problem by development of novel bioactive materials, among which bioactive glass is the most attractive because of its osteoconductive and osteostimulative properties. Since lipid peroxidation is an important component of systematic stress response in patients with traumatic brain injuries and bone fractures, studies have been undertaken of the molecular mechanisms of the involvement of 4-hydroxynonenal (HNE), an end product of lipid peroxidation, in cellular growth regulation. We found that HNE generated in bone cells grown in vitro on the surfaces of bioactive glasses 45S5 and 13-93. This raises an interesting possibility of combined action of HNE and ionic bioglass dissolution products in enhanced osteogenesis probably through a mitogen-activated protein kinase (MAPK) pathway. While the proposed mechanism still has to be elucidated, the finding of HNE generation on bioglass offers a new interpretation of the osteoinducting mechanisms of bioglass and suggests the possibility of tissue engineering based on manipulations of oxidative homeostasis.
4
88%
EN
Addition of CaF2 to a silicate bioactive glass favours formation of fluorapatite, which is less soluble in acidic environment than hydroxyapatite. However, excess CaF2 in the glass is problematic, owing to the formation of crystalline calcium fluoride rather than fluorapatite on immersion. In this paper we investigate chloride as an alternative to fluoride in bioactive silicate glasses and in particular their bioactivity for the first time. Meltderived bioactive glasses based on SiO2-P2O5-CaO-CaCl2 with varying CaCl2 contents were synthesised and characterised by DSC. Chemical analysis of the chloride content was performed by using an ion selective electrode. Glass density was determined using Helium Pycnometry. The glass bioactivity was investigated in Tris buffer. Ion release measurements were carried out by using ICP-OES. The chemical analysis results indicated that the majority of the chloride is retained in the Q2 type silicate glasses during synthesis. Tg and glass density reduced with increasing CaCl2 content. Apatite-like phase formation was confirmed by FITR, XRD and 31P MAS-NMR. The results of the in vitro studies demonstrated that the chloride containing bioactive glasses are highly degradable and form apatite-like phase within three hours in Tris buffer and, therefore, are certainly suitable for use in remineralising toothpastes. The dissolution rate of the glass was found to increase with CaCl2 content. Faster dissolving bioactive glasses may be attractive for more resorbable bone grafts and scaffolds.
|
|
vol. 1
|
issue 1
EN
Ion release of Mg- and Zn-substituted Bioglass 45S5 (46.1 SiO2-2.6 P2O5-26.9 CaO-24.3Na2O; mol%; with 0, 25, 50, 75 or 100% of calcium replaced bymagnesium/zinc) was investigated at pH 7.4 (Tris buffer) and pH 4 (acetic acid/sodium acetate buffer) in static and dynamic dissolution experiments. Despite Mg2+ and Zn2+ having the same charge and comparable ionic radii, they influenced the dissolution behaviour in very different ways. In Tris, Mgsubstituted glasses showed similar ion release as 45S5, while Zn-substituted glasses showed negligible ion release. At low pH, however, release behaviour was similar, with all glasses releasing large percentages of ions within a few minutes. Precipitation of crystalline phases also varied, as Mg- and Zn-substitution inhibited apatite formation, and Zn-substitution resulted in formation of zinc phosphate phases at low pH. These results are relevant for glasses used in aluminium-free glass ionomer bone cements, as they show that Zn/Mg-substituted glasses release ions similarly fast as glasses containing no Zn/Mg, suggesting that these ions are no prerequisite for ionomer glasses. Zn-substituted glasses may potentially be used as controlled-release materials, which release antibacterial zinc ions when needed only, i.e. at low pH conditions (e.g. bacterial infection), but not at normal physiological pH conditions.
first rewind previous Page / 1 next fast forward last
JavaScript is turned off in your web browser. Turn it on to take full advantage of this site, then refresh the page.