Periodontal disease is a significant burden for oral health, causing progressive and irreversible damage to the support structure of the tooth. This complex structure, the periodontium, is composed of interconnected soft and mineralised tissues, posing a challenge for regenerative approaches. Materials combining silicon and lithium are widely studied in periodontal regeneration, as they stimulate bone repair via silicic acid release while providing regenerative stimuli through lithium activation of the Wnt/β-catenin pathway. Yet, existing materials for combined lithium and silicon release have limited control over ion release amounts and kinetics. Porous silicon can provide controlled silicic acid release, inducing osteogenesis to support bone regeneration. Prelithiation, a strategy developed for battery technology, can introduce large, controllable amounts of lithium within porous silicon, but yields a highly reactive material, unsuitable for biomedicine. This work debuts a strategy to lithiate porous silicon nanowires (LipSiNs) which generates a biocompatible and bioresorbable material. LipSiNs incorporate lithium to between 1% and 40% of silicon content, releasing lithium and silicic acid in a tailorable fashion from days to weeks. LipSiNs combine osteogenic, cementogenic and Wnt/β-catenin stimuli to regenerate bone, cementum and periodontal ligament fibres in a murine periodontal defect.
- MeSH
- beta-katenin * MeSH
- křemík farmakologie MeSH
- kyselina křemičitá farmakologie MeSH
- lithium farmakologie MeSH
- myši MeSH
- nanodráty * MeSH
- poréznost MeSH
- zubní cement (tkáň) MeSH
- zvířata MeSH
- Check Tag
- myši MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
Silicate minerals are dominant soil components. Thus, plant roots are constantly exposed to silicic acid. High silicon intake, enabled by root silicon transporters, correlates with increased tolerance to many biotic and abiotic stresses. However, the underlying protection mechanisms are largely unknown. Here, we tested the hypothesis that silicon interacts with the plant hormones, and specifically, that silicic acid intake increases cytokinin biosynthesis. The reaction of sorghum (Sorghum bicolor) and Arabidopsis plants, modified to absorb high versus low amounts of silicon, to dark-induced senescence was monitored, by quantifying expression levels of genes along the senescence pathway and measuring tissue cytokinin levels. In both species, detached leaves with high silicon content senesced more slowly than leaves that were not exposed to silicic acid. Expression levels of genes along the senescence pathway suggested increased cytokinin biosynthesis with silicon exposure. Mass spectrometry measurements of cytokinin suggested a positive correlation between silicon exposure and active cytokinin concentrations. Our results indicate a similar reaction to silicon treatment in distantly related plants, proposing a general function of silicon as a stress reliever, acting via increased cytokinin biosynthesis.
- MeSH
- Arabidopsis účinky léků genetika metabolismus MeSH
- cytokininy biosyntéza MeSH
- geneticky modifikované rostliny MeSH
- kořeny rostlin metabolismus MeSH
- křemík metabolismus farmakologie MeSH
- listy rostlin účinky léků metabolismus fyziologie MeSH
- mutace MeSH
- regulace genové exprese u rostlin MeSH
- Sorghum účinky léků genetika metabolismus MeSH
- Publikační typ
- časopisecké články MeSH
Silicon was shown to alleviate the negative effects of various biotic and abiotic stresses on plant growth. Although the positive role of Si on toxic and heavy metal Cd has been already described, the mechanisms have been explained only partially and still remain unclear. In the present study we investigated the effect of Si on photosynthetic-related processes in maize exposed to two different levels of Cd via measurements of net photosynthetic rate (AN), chlorophyll a fluorescence and pigment analysis, as well as studies of leaf tissue anatomy and cell ultrastructure using bright-field and transmission electron microscopy. We found that Si actively alleviated the toxic syndromes of Cd by increasing AN, effective photochemical quantum yield of photosystem II (ϕPSII) and content of assimilation pigments, although did not decrease the concentration of Cd in leaf tissues. Cadmium did not affect the leaf anatomy and ultrastructure of leaf mesophyll's cell chloroplasts; however, Cd negatively affected thylakoid formation in chloroplasts of bundle sheath cells, and this was alleviated by Si. Improved thylakoid formation in bundle sheath's cell chloroplasts may contribute to Si-induced enhancement of photosynthesis and related increase in biomass production in C4 plant maize.
- MeSH
- chlorofyl analogy a deriváty metabolismus MeSH
- chloroplasty účinky léků metabolismus ultrastruktura MeSH
- fluorescence MeSH
- fotosyntéza účinky léků MeSH
- fotosystém II - proteinový komplex metabolismus MeSH
- kadmium toxicita MeSH
- křemík farmakologie MeSH
- kukuřice setá účinky léků metabolismus ultrastruktura MeSH
- listy rostlin účinky léků MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Hydroxyapatite layers with silver doping from 0.06 at.% to 14 at.% were prepared by laser deposition. The films' physical properties such as morphology, composition, crystallinity, Young's modulus and microhardness were measured. Films were amorphous or polycrystalline in dependence on deposition temperature (from RT to 600 °C). Antibacterial properties were tested using Escherichia coli and Bacillus subtilis cells. The antibacterial efficacy changed with silver doping from 4% to 100%. Cytotoxicity was studied by a direct contact test. Depending on doping and crystallinity the films were either non-toxic or mildly toxic.
- MeSH
- antibakteriální látky farmakologie MeSH
- buněčná smrt účinky léků MeSH
- buňky NIH 3T3 MeSH
- difrakce rentgenového záření MeSH
- Escherichia coli účinky léků MeSH
- fibroblasty cytologie účinky léků MeSH
- hydroxyapatit farmakologie MeSH
- křemík farmakologie MeSH
- krystalizace MeSH
- lasery * MeSH
- mikrobiální testy citlivosti MeSH
- mikroskopie elektronová rastrovací MeSH
- modul pružnosti účinky léků MeSH
- myši MeSH
- Staphylococcus aureus účinky léků MeSH
- titan farmakologie MeSH
- tvrdost účinky léků MeSH
- zvířata MeSH
- Check Tag
- myši MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Recently, a growing interest has been recorded in mineral content of mammalian diet, which might impair their development. Focused on the topic, we studied the effect of Al3+, Si4+, Sr2+ and Na2S on the intensity of malondialdehyde (MDA) production in vitro. MDA, as one of oxidative stress markers, was determined in rat brain homogenates in the conditions of lipid peroxidation (LP) activated by iron ions and ascorbate. Our results showed a significant increase in lipid peroxidation after addition of aluminium ions. We assume a probable impact of Al3+ on active or regulatory centres of antioxidant enzymes, resulting in the reduction of their antioxidant functions. The addition to Si4+ or Na2S to samples with Al3+ significantly decreased Fe2+-activated LP. We can explain the influence of Na2S by the formation of insoluble complexes with iron. Similarly, the effect of Si4+ can be related to the production of aluminium-silicon complexes. In our view, an optimal ratio of aluminium and silicon ions (or aluminium ions and Na2S) in the diet might have beneficial effects on brain functions.
- MeSH
- hliník farmakologie MeSH
- křemík farmakologie MeSH
- krysa rodu rattus MeSH
- malondialdehyd metabolismus MeSH
- mozek metabolismus MeSH
- peroxidace lipidů účinky léků MeSH
- potkani Wistar MeSH
- sulfidy farmakologie MeSH
- železo farmakologie MeSH
- zvířata MeSH
- Check Tag
- krysa rodu rattus MeSH
- zvířata MeSH
- Publikační typ
- práce podpořená grantem MeSH
