The quantification of cellular metabolic activity via MTT assay has become a widespread practice in eukaryotic cell studies and is progressively extending to bacterial cell investigations. This study pioneers the application of MTT assay to evaluate the metabolic activity of biofilm-forming cells within bacterial biofilms on nanofibrous materials. The biofilm formation of Staphylococcus aureus and Escherichia coli on nanomaterials electrospun from polycaprolactone (PCL), polylactic acid (PLA), and polyamide (PA) was examined. Various parameters of the MTT assay were systematically investigated, including (i) the dissolution time of the formed formazan, (ii) the addition of glucose, and (iii) the optimal wavelength for spectrophotometric determination. Based on interim findings, a refined protocol suitable for application to nanofibrous materials was devised. We recommend 2 h of the dissolution, the application of glucose, and spectrophotometric measurement at 595 nm to obtain reliable data. Comparative analysis with the reference CFU counting protocol revealed similar trends for both tested bacteria and all tested nanomaterials. The proposed MTT protocol emerges as a suitable method for assessing the metabolic activity of bacterial biofilms on PCL, PLA, and PA nanofibrous materials.
- MeSH
- biofilmy * růst a vývoj MeSH
- Escherichia coli * fyziologie MeSH
- glukosa metabolismus MeSH
- nanovlákna * chemie MeSH
- nylony chemie MeSH
- polyestery * chemie MeSH
- spektrofotometrie metody MeSH
- Staphylococcus aureus * fyziologie MeSH
- tetrazoliové soli * metabolismus chemie MeSH
- thiazoly metabolismus MeSH
- Publikační typ
- časopisecké články MeSH
- MeSH
- brýle * MeSH
- dějiny 20. století MeSH
- lidé MeSH
- nylony MeSH
- Check Tag
- dějiny 20. století MeSH
- lidé MeSH
- Publikační typ
- historické články MeSH
Double stimuli-responsive functionalized cellulose nanocrystal-poly[2-(dimethylamino)ethyl methacrylate] (CNC-g-PDMAEMA) reinforced poly(3-hydroxybutyrate-co-3-hydroxy valerate) (PHBV) electrospun composite membranes were explored as drug delivery vehicles using tetracycline hydrochloride (TH) as a model drug. It was found that rigid CNC-g-PDMAEMA nanoparticles enhanced thermal, crystallization and hydrophilic properties of PHBV. Moreover, great improvements in fiber diameter uniformity, crystallization ability and maximum decomposition temperature (Tmax) could be achieved at 6 wt% CNC-g-PDMAEMA. Furthermore, by introducing stimuli-responsive CNC-g-PDMAEMA nanofillers, intelligent and long-term sustained release behavior of composite membranes could be achieved. The releasing mechanism of composite membranes based on zero order, first order, Higuchi and Korsmeyere-Peppas mathematical models was clearly demonstrated, giving effective technical guidance for practical drug delivery systems.
- MeSH
- lidé MeSH
- nylony * MeSH
- syntetické pryskyřice MeSH
- zubní materiály MeSH
- zubní náhrady - baze * MeSH
- zubní náhrady - oprava * MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- kazuistiky MeSH
- MeSH
- lidé MeSH
- nylony MeSH
- zubní materiály * MeSH
- zubní náhrady - přesné přichycení * MeSH
- Check Tag
- lidé MeSH
Bezpečnost potravin může ovlivnit mnoho různých faktorů, jedním z nich jsou i výrobky, které jsou určeny pro styk s potravinami. Materiály a předměty, které přichází do styku s potravinami, musí být vyrobeny v souladu se správnou výrobní praxí a musí splňovat hygienické požadavky. Do potravin nesmí uvolňovat své složky a tím nepříznivě ovlivnit bezpečnost a kvalitu potravin. Pokud tyto výrobky nevyhovují požadavkům platné legislativy, mohou být jedním ze zdrojů kontaminace potravin a následného ohrožení zdraví spotřebitelů. V tomto článku je uveden přehled materiálů, které se nejčastěji používají k výrobě kuchyňského nádobí a náčiní a zdravotní rizika z kontaminace potravin chemickými látkami, uvolňujícími se z materiálu nádobí. Dále jsou zmíněny případy přenosu rizikových látek z kuchyňského nádobí a náčiní do potravin, zjištěné v Moravskoslezském kraji, České republice a v zahraničí..
Safety of food can be influenced by many factors, including articles intended to come into contact with food. Materials and subjects which come into contact with food must be produced according to good manufacturing practice and must fulfill hygienic requirements. They cannot release their components into food and by this negatively influence safety and quality of food. If these articles do not fulfill requirements of valid legislation, they can be one of the sources of food contamination and following threat to life of consumers. In this article, there is a list of materials which are most commonly used for production of kitchen utensils and medical risks of food contamination by chemicals released from the material of the utensils. Further in the article there are cases of transfer of hazardous substances from kitchen utensils into food in the Moravian-Silesian region, the Czech Republic and abroad.
Periprosthetic bone loss in response to total hip arthroplasty is a serious complication compromising patient's life quality as it may cause the premature failure of the implant. Stress shielding as a result of an uneven load sharing between the hip implant and the bone is a key factor leading to bone density decrease. A number of composite hip implants have been designed so far to improve load sharing characteristics. However, they have rarely been investigated from the bone remodeling point of view to predict a long-term response. This is the first study that employed a mechano-biochemical model, which considers the coupling effect between mechanical loading and bone biochemistry, to investigate bone remodeling after composite hip implantation. In this study, periprosthetic bone remodeling in the presence of Carbon fiber polyamide 12 (CF/PA12), CoCrMo and Ti alloy implants was predicted and compared. Our findings revealed that the most significant periprosthetic bone loss in response to metallic implants occurs in Gruen zone 7 (-43% with CoCrMo; -35% with Ti) and 6 (-40% with CoCrMo; -29% with Ti), while zone 4 has the lowest bone density decrease with all three implants (-9%). Also, the results showed that in terms of bone remodeling, the composite hip implant is more advantageous over the metallic ones as it provides a more uniform density change across the bone and induces less stress shielding which consequently results in a lower post-operative bone loss (-9% with CF/PA12 implant compared to -27% and -21% with CoCrMo and Ti alloy implants, respectively).
- MeSH
- analýza metodou konečných prvků MeSH
- biologické modely * MeSH
- biomechanika MeSH
- biomimetické materiály škodlivé účinky MeSH
- kostní denzita účinky léků MeSH
- kyčelní kloub účinky léků fyziologie chirurgie MeSH
- kyčelní protézy škodlivé účinky MeSH
- mechanický stres * MeSH
- modul pružnosti účinky léků MeSH
- nylony škodlivé účinky chemie MeSH
- pooperační období MeSH
- remodelace kosti účinky léků MeSH
- slitiny škodlivé účinky MeSH
- uhlík chemie MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- srovnávací studie MeSH
