Foliar Fertilization by the Sol-Gel Particles Containing Cu and Zn

Silica particles with the size of 150-200 nm containing Ca, P, Cu or Zn ions were synthesized with the sol-gel method and tested as a foliar fertilizer on three plant species: maize Zea mays, wheat Triticum sativum and rape Brassica napus L. var napus growing on two types of soils: neutral and acidic. The aqueous suspensions of the studied particles were sprayed on the chosen leaves and also on the whole tested plants. At a specific stage of plant development determined according to the BBCH (Biologische Bundesanstalt, Bundessortenamt und CHemische Industrie) scale, the leaves and the whole plants were harvested and dried, and the content of Cu and Zn was determined with the AAS (atomic absorption spectroscopy) method. The engineered particles were compared with a water solution of CuSO₄ and ZnSO₄ (0.1%) used as a conventional fertilizer. In many cases, the copper-containing particles improved the metal supply to plants more effectively than the CuSO₄. The zinc-containing particles had less effect on both the growth of plants and the metal concentration in the plants. All the tested particles were not toxic to the examined plants, although some of them caused a slight reduction in plants growth.

Antiadherent and antibacterial properties of TiO2-coated and TiO2:Ag-coated stainless steel orthodontic wires against S. mutans bacteria

Purpose

Conventional orthodontic treatment with stainless steel orthodontic wires may be detrimental to oral health, as it con-tributes to demineralized lesions and increases adhesion and bacterial biofilm formation, which contributes to cavity development. An alternative that has been investigated to reduce the side effects of orthodontic treatment is the use of coating materials with antimicrobial nanoparticles. This study aims to evaluate the antiadherent and antibacterial properties of TiO2-coated and TiO2:Ag-coated stainless steel orthodontic wires against S. mutans bacteria.

Methods

In the sol-gel method, TiO2:Ag thin films were deposited on stainless steel orthodontic wires. Coated archwires were analyzed for their antibacterial and antiadherent properties. The evaluation of Streptococcus mutans adhesion to the orthodontic wires’ surface was conducted according to the type of coating used, biofilm formation assay, and measure-ment of the pH of the bacterial community.

Results

In the microbiological test, the TiO2:Ag coatings revealed a statistically significant difference in terms of microbial adhesion and biofilm formation by Streptococcus mutans. The TiO2:Ag coating on stainless steel wire increased pH levels in the saliva environment.

Conclusions

It can be concluded that antimicrobial orthodontic wires coated with silver-TiO2 nanoparticles using the sol-gel thin film are a promising choice for improving orthodontic treatment.

Antiadherent and antibacterial properties of TiO2-coated and TiO2:Ag-coated stainless steel orthodontic wires against S. mutans bacteria

PURPOSE

Conventional orthodontic treatment with stainless steel orthodontic wires may be detrimental to oral health, as it contributes to demineralized lesions and increases adhesion and bacterial biofilm formation, which contributes to cavity development. An alternative that has been investigated to reduce the side effects of orthodontic treatment is the use of coating materials with antimicrobial nanoparticles. This study aims to evaluate the antiadherent and antibacterial properties of TiO2-coated and TiO2:Ag-coated stainless steel orthodontic wires against S. mutans bacteria.

METHODS

In the sol-gel method, TiO2:Ag thin films were deposited on stainless steel orthodontic wires. Coated archwires were analyzed for their antibacterial and antiadherent properties. The evaluation of Streptococcus mutans adhesion to the orthodontic wires' surface was conducted according to the type of coating used, biofilm formation assay, and measurement of the pH of the bacterial community.

RESULTS

In the microbiological test, the TiO2:Ag coatings revealed a statistically significant difference in terms of microbial adhesion and biofilm formation by Streptococcus mutans. The TiO2:Ag coating on stainless steel wire increased pH levels in the saliva environment.

CONCLUSIONS

It can be concluded that antimicrobial orthodontic wires coated with silver TiO2 nanoparticles using the sol-gel thin film are a promising choice for improving orthodontic treatment.

In vivo study on the biodistribution of silica particles in the bodies of rats

BACKGROUND

Biodegradable carrier materials with nontoxic degradation products are very valuable for delivering drugs and biologically active molecules. Many organic systems (such as liposomes, micelles and polymeric nanoparticles) and inorganic systems (metal oxides and silica) have been researched for delivering active substances to organs. Silica seems to be one of the most interesting and promising materials.

OBJECTIVES

The aim of this study was to investigate the SiO2 elimination process from rats' organisms and to ascertain the distribution and prospective accumulation sites of the silica particles.

MATERIAL AND METHODS

A suspension of silica particles (Ø 150 nm) in 0.9% NaCl solution was introduced into rats' circulatory system. The degradation of these particles over time and their accumulation in the heart, lungs, kidneys and liver were observed.

RESULTS

It was found that 36% of the introduced silica particles were excreted with urine after four days. The remaining particles were accumulated in the kidneys and lungs, probably in the lung air sacs and kidney glomerulus.

CONCLUSIONS

Silica seems to be promising carrier material. Silica particles dissolve in the rat's body and are eliminated in urine.

Behavior of silica particles introduced into an isolated rat heart as potential drug carriers

Silica powders consisting of small spherical particles (50-200 nm) have been obtained by the sol-gel method. A suspension of such particles in the Krebs-Hanseleit solution has been introduced into the coronary circulation of a beating perfused rat heart. The influence of the suspension on the heart muscle and the coronary vessels in the rat body has been histopathologically examined. The particles have not left the lumen of the vessels and have not caused any side effects. These observations suggest the possibility of using such silica particles as a carrier for selected drugs.