Search results for "Biomedical engineering"

An impaired alveolar-capillary barrier in vitro : effect of proinflammatory cytokines and consequences on nanocarrier interaction.

2009

The alveolar region of the lung is an important target for drug and gene delivery approaches. Treatment with drugs is often necessary under pathophysiological conditions, in which there is acute inflammation of the target organ. Therefore, in vitro models of the alveolar-capillary barrier, which mimic inflammatory conditions in the alveolar region, would be useful to analyse and predict effects of novel drugs on healthy or inflamed tissues. The epithelial cell line H441 was cultivated with primary isolated human pulmonary microvascular endothelial cells (HPMECs) or the endothelial cell line ISO-HAS-1 on opposite sides of a permeable filter support under physiological and inflammatory condi…

Fluorescein- and EGFR-Antibody Conjugated Silica Nanoparticles for Enhancement of Real-time Tumor Border Definition Using Confocal Laser Endomicrosco…

2019

Intraoperative definition of tumor free resection margins in head and neck cancer is challenging. In the current proof-of-principle study we evaluated a novel silica nanoparticle-based agent for its potential use as contrast enhancer. We synthesized silica nanoparticles with an average size of 45 nm and modified these particles with the fluorescence stain fluorescein isocyanate (FITC) for particle detection and with epidermal growth factor receptor (EGFR)-targeting antibodies for enhanced tumor specificity. The nanoparticles exhibited good biocompatibility and could be detected in vitro and in vivo by confocal laser scanning microscopy. Additionally, we show in an ex vivo setting that these…

Microstructures in shells of the freshwater gastropod Viviparus viviparus: a potential sensor for temperature change?

2013

Abstract Mollusk shells contain a plethora of information on past climate variability. However, only a limited toolkit is currently available to reconstruct such data from the shells. The environmental data of some proxies (e.g. Sr/Ca ratios) is obscured by physiological effects, whereas other proxies, such as δ 18 O, simultaneously provide information on two or more different environmental variables. The present study investigates whether microstructures of the freshwater gastropod Viviparus viviparus provide an alternative means to reconstruct past water temperature. Cold and highly variable temperature regimes resulted in the precipitation of highly unordered first-order lamellae of simp…

Influence of oxygen tension on the anti-inflammatory and chondroprotective effects of heme oxygenase-1 in healthy and osteoarthritic human chondrocyt…

2012

s / Osteoarthritis and Cartilage 20 (2012) S54–S296 S136 their isolation. The absence of cross-reaction with the IIA isoform was established by ELISA andWB. In addition, the Saos-2 cell linewas chosen to test a possible labelling of other fibrillar procollagens, mainly type I, V and XI. In fact, this cell line is described to synthesize the (a1)I, (a2)I, (a1)V, (a2)V, (a1)XI and (a2)XI, but no (a3)XI chains. No signal was detected on WB of cellular extracts or conditioned media with anti-pNIIB52, whereas antibodies to the collagen I, V and XI triple-helical parts revealed indeed the presence of proforms of these collagens. Conclusions: Anti-pNIIB52 antibodies allow a very sensitive and spec…

Surface Modification of Porous Polyethylene Implants with an Albumin-Based Nanocarrier-Release System

2021

Background: Porous polyethylene (PPE) implants are used for the reconstruction of tissue defects but have a risk of rejection in case of insufficient ingrowth into the host tissue. Various growth factors can promote implant ingrowth, yet a long-term gradient is a prerequisite for the mediation of these effects. As modification of the implant surface with nanocarriers may facilitate a long-term gradient by sustained factor release, implants modified with crosslinked albumin nanocarriers were evaluated in vivo. Methods: Nanocarriers from murine serum albumin (MSA) were prepared by an inverse miniemulsion technique encapsulating either a low- or high-molar mass fluorescent cargo. PPE implants …

Boron Ions: Simultaneous Boron Ion‐Channel/Growth Factor Receptor Activation for Enhanced Vascularization (Adv. Biosys. 1/2019)

2019

Enhanced tissue penetration of antibodies through pressurized immunohistochemistry

2020

ABSTRACTTo address the inefficiency of passive diffusion for antibody penetration in thick tissue samples, which limits clearing-technique applications, we developed a versatile and simple device to perform antibody incubation under increased barometric pressure. Pressurized immunohistochemistry greatly improves the uniformity, intensity, and depth of fluorescent immunostaining in thick human and mouse brain samples. Furthermore, pressurized immunohistochemistry substantially decreases the time required for classic staining of thin sections.SUBMISSION CATEGORYNew Results

Anhydrobiosis in yeast: FT-IR spectroscopic studies of yeast grown under conditions of severe oxygen limitation

2014

Anhydrobiosis is a unique state of living organisms when metabolism is temporarily and reversibly delayed in response to the extreme desiccation of cells. The production of dry active preparations of yeast grown under anaerobic conditions is not currently possible because preparations are extremely sensitive to the dehydration procedure, though they could be very helpful in different biotechnological processes, including bioethanol production. To characterize mechanisms responsible for such sensitivity to the dehydration procedure, Fourier transform infrared spectroscopy was used to study the composition of aerobically grown yeast Saccharomyces cerevisiae resistant to dehydration and grown …

Endothelial cells stimulate osteogenic differentiation of mesenchymal stem cells on calcium phosphate scaffolds

2012

The interaction of mesenchymal stem cells (MSCs) with endothelium in vivo is significant for regenerative processes in organisms. To design concepts for tissue engineering for bone regeneration based on this interaction, the osteogenic differentiation of human bone marrow-derived MSCs in a co-culture with human dermal microvascular endothelial cells (HDMECs) was studied. The experiments were focussed on the regulation of MSCs in a co-culture with HDMECs on different calcium phosphate scaffolds. Alkaline phosphatase (ALP) activity and mRNA expression of various osteogenic markers increased significantly when cells were co-cultured on materials with calcium phosphate scaffolds compared to tis…

Antibacterial activity of different root canal sealers against Enterococcus faecalis

2017

Background The aim of the present study was to compare in vitro the antimicrobial activity of different root canal sealers against Enterococcus faecalis, prior and subsequent to setting. Material and methods Agar diffusion test (ADT) was used for evaluating the antibacterial activity of non-set sealer while the direct contact test (DCT) was used for after setting. Results ADT: Except for TotalFill BC Sealer all the others sealers tested showed antibacterial activity. BioRoot™RCS, MTA Fillapex and Sealapex Root Canal Sealer showed the lowest antibacterial activity, a significant increase in antibacterial effect for both Pulp Canal Sealer™ and AH plus sealers were found. Significantly higher …