In Vitro AuNPs’ Cytotoxicity and Their Effect on Wound Healing

Recently, due to their unique properties, gold nanoparticles (AuNPs) have been used in many biological applications. However, little is known about their toxicity when they come into contact with a biological system. Based on the proposal that AuNPs can have a positive effect on wound healing, the present study investigated the influence of negatively-charged-surface AuNPs (average diameter 25-50 nm) on the viability of normal human dermal fibroblasts (NHDF) and normal human epidermal keratinocytes (NHEK). Moreover, we evaluated the effect of AuNPs on the secretion of proteins involved in wound healing, such as interleukin-8 and -12 (IL-8, IL-12), tumour necrosis factor-alpha (TNF-α), vascular endothelial growth factor (VEGF), basic fibroblast grow factor (bFGF), and granulocyte-macrophage colony-stimulating factor (GM-CSF). The results showed that AuNPs were not toxic to NHDF and NHEK. They showed a decrease in AuNPs’ production of pro-inflammatory cytokines IL-6, IL-12 and TNF-α, as well as proteins involved in angiogenesis such as VEGF and bFGF. Thus, we suggest that AuNPs could have anti-inflammatory and anti-angiogenic activity

Biocompatible Hydrogelators Based on Bile Acid Ethyl Amides

Four novel bile acid ethyl amides were synthetized using a well-known method. All the four compounds were characterized by IR, SEM, and X-ray crystal analyses. In addition, the cytotoxicity of the compounds was tested. Two of the prepared compounds formed organogels. Lithocholic acid derivative 1 formed hydrogels as 1% and 2% (w/v) in four different aqueous solutions. This is very intriguing regarding possible uses in biomedicine.peerReviewe

Objasnění mechanismů mazání v náhradě kolenního kloubu – Část I: Experimentální studium

This contribution is aimed at the detailed understanding of lubrication mechanisms within total knee replacement. While Part I is focused on the experimental investigation, Part II deals with the development of a predictive numerical model. Here, a knee simulator was used for direct optical observation of the contacts between a metal femoral and a transparent polymer components. Transient dynamic conditions were applied. Mimicked synovial fluids with fluorescently labelled constituents were used as the test lubricants. The results showed that -globulin forms thin boundary lubricating film, being reinforced by the interaction of phospholipids and hyaluronic acid. Further development of lubricating film is attributed to albumin layering. Based on the results, a novel lubrication model of the knee implant is proposed.Tato studie je zaměřena na detailní porozumění mechanismů mazání v náhradě kolenního kloubu. Zatímco část I představuje experimentální pozorování, část II se zabývá vývojem prediktivního numerického modelu. V této části studie byl využit kolenní simulátor pro přímé optické pozorování kontaktu kovové femorální komponenty a vložky zhotovené z průhledného polymeru. Byly aplikovány proměnné dynamické podmínky. Jako mazivo byly využity modelové synoviální kapaliny s fluorescenčně označenými složkami. Výsledky ukázaly, že -globulin má tendenci formovat tenkou meznou vrstvu, která je vyztužená fosfolipidy v interakci s kyselinou hyaluronovou. Další nárůst mazacího filmu je připisován vrstvení albuminu. Na základě výsledků je představen nový teoretický model mazací vrstvy v kolenní náhradě