Amino-acid-derived polyzwitterions and polybetaines (PBs) are two promising alternatives to non-ionic polymers, for example, to increase tumor permeability. In this study, amino-acid-derived polyzwitterions are synthesized and a strategy to quarternize the amine in the side chain functional group is developed to combine the advantages of both types. The functional monomer is polymerized via reversible addition-fragmentation chain-transfer polymerization for which a kinetic study is performed.
View Article and Find Full Text PDFMicroplastics (MP) have become a well-known and widely investigated environmental pollutant. Despite the huge amount of new studies investigating the potential threat posed by MP, the possible uptake and trophic transfer in lower trophic levels of freshwater ecosystems remains understudied. This study aims to investigate the internalization and potential trophic transfer of fluorescent polystyrene (PS) beads (0.
View Article and Find Full Text PDFDue to global pollution derived from plastic waste, the research on microplastics is of increasing public interest. Until now, most studies addressing the effect of microplastic particles on vertebrate cells have primarily utilized polystyrene particles (PS). Other studies on polymer microparticles made, e.
View Article and Find Full Text PDFPurpose: Meniscal allografts and biodegradable meniscal implants are attractive surgical options for painful subtotal or total meniscectomies. In order to get the best results, these should be as similar as possible to the original meniscus in terms of shape, structure, and volume. Three-dimensional meniscus sizing could be an approach to improve the accuracy of meniscus matching.
View Article and Find Full Text PDFPolystyrene (PS) is an important model polymer for the investigation of effects of microplastic (MP) and nanoplastic (NP) particles on living systems. Aqueous dispersions of PS MP or NP contain residual monomers of styrene. In consequence, it is not clear if the effects observed in standard (cyto)toxicity studies are evoked by the polymer (MP/NP) particle or by residual monomers.
View Article and Find Full Text PDFBiodegradable electrospun sponges are of interest for various applications including tissue engineering, drug release, dental therapy, plant protection, and plant fertilization. Biodegradable electrospun poly(l-lactide)/poly(ε-caprolactone) (PLLA/PCL) blend fiber-based sponge with hierarchical pore structure is inherently hydrophobic, which is disadvantageous for application in tissue engineering, fertilization, and drug delivery. Contact angles and model studies for staining with a hydrophilic dye for untreated, plasma-treated, and surfactant-treated PLLA/PCL sponges are reported.
View Article and Find Full Text PDFThe impact of microplastic particles on organisms is currently intensely researched. Although it is well established that macrophages ingest polystyrene (PS) microparticles, little is known about the subsequent fate of the particles, such as entrapment in organelles, distribution during cell division, as well as possible mechanisms of excretion. Here, submicrometer (0.
View Article and Find Full Text PDFBackground: One of the most complex prokaryotic organelles are magnetosomes, which are formed by magnetotactic bacteria as sensors for navigation in the Earth's magnetic field. In the alphaproteobacterium Magnetospirillum gryphiswaldense magnetosomes consist of chains of magnetite crystals (FeO) that under microoxic to anoxic conditions are biomineralized within membrane vesicles. To form such an intricate structure, the transcription of > 30 specific structural genes clustered within the genomic magnetosome island (MAI) has to be coordinated with the expression of an as-yet unknown number of auxiliary genes encoding several generic metabolic functions.
View Article and Find Full Text PDFPolyelectrolyte microcapsules based on sodium cellulose sulfate (SCS) and poly-diallyl-dimethyl-ammonium chloride (PDADMAC) have previously been proposed as a suitable ex vivo microenvironment for the cultivation and differentiation of primary human T lymphocytes. Here, the same system is investigated for the cultivation of human primary B cells derived from adult tonsillar tissue. Proliferation and differentiation into subtypes are followed and compared to suspension cultures of B cells from the same pool performed in parallel.
View Article and Find Full Text PDFMicroplastic particles are pollutants in the environment with a potential impact on ecology and human health. As soon as microplastic particles get in contact with complex (biological) environments, they will be covered by an eco- and/or protein corona. In this contribution, protein corona formation was conducted under defined laboratory conditions on polystyrene (PS) microparticles to investigate the influence on surface properties, protein corona evolution, particle-cell interactions, and uptake in two murine epithelial cells.
View Article and Find Full Text PDFElectrospun nanofibers can be effectively used as a surrogate for extracellular matrices (ECMs). However, in the context of cellular mechanobiology, their mechanical performances can be enhanced by using nanofibrous materials with a high level of structural organization. Herein, this work develops multifibrillar yarns with superior mechanical performance based on biocompatible polyacrylonitrile (PAN) as surrogate ECM.
View Article and Find Full Text PDFMicroplastic particles (MP) and nanoplastic particles (NP) as persistent anthropogenic pollutants may impact environmental and human health. A relevant potential source of primary MP and NP is water-based dispersion paint which are commonly used in any household. Given the worldwide high application volume of dispersion paint and their diverse material composition MP and NP may enter the environment with unforeseeable consequences.
View Article and Find Full Text PDFMicroplastic particles (MP), arising from the gradual decomposition of plastics in the environment, have been identified as a global problem. Most investigations of MP cytotoxicity use pristine spherical particles available from commercial sources when evaluating their impact on mammalian cells, while only limited data is available for the more relevant "weathered microplastic". In this study, we exposed murine macrophages to polystyrene MP either after up to 130 days of accelerated ageing or in pristine condition.
View Article and Find Full Text PDFNonviral gene delivery vectors are attractive candidates compared to viral ones due to their lower cytotoxicity and immunogenicity. However, their efficacy still requires improvement. Major challenges are the effective complexation and protection of the DNA cargo and the intracellular dissociation of the polyplexes at the site of action.
View Article and Find Full Text PDFMicroplastics and its putative adverse effects on environmental and human health increasingly gain scientific and public attention. Systematic studies on the effects of microplastics are currently hampered by using rather poorly characterised particles, leading to contradictory results for the same particle type. Here, surface properties and chemical composition of two commercially available nominally identical polystyrene microparticles, frequently used in effect studies, were characterised.
View Article and Find Full Text PDFThe earthworm Eisenia fetida is a commonly used model organism for unspecific soil feeders in ecotoxicological studies. Its intestinal cells are the first to encounter possible pollutants co-ingested by the earthworm, which makes them prime candidates for studies of toxic effects of environmental pollutants on the cellular as compared to the organismic level. In this context, the aim of this study was to demonstrate the suitability of preparations of primary intestinal E.
View Article and Find Full Text PDFAlthough the development of gene delivery systems based on non-viral vectors is advancing, it remains a challenge to deliver plasmid DNA into human blood cells. The current "gold standard", namely linear polyethyleneimine (l-PEI 25 kDa), in particular, is unable to produce transgene expression levels >5% in primary human B lymphocytes. Here, it is demonstrated that a well-defined 24-armed poly(2-dimethylamino) ethyl methacrylate (PDMAEMA, 755 kDa) nano-star is able to reproducibly elicit high transgene expression (40%) at sufficient residual viability (69%) in primary human B cells derived from tonsillar tissue.
View Article and Find Full Text PDFMicroplastic (MP) contamination has been identified as an ecological problem with an increasing impact on everyday life. Yet, possible effects of MP at the cellular level are still poorly understood. Here, the interaction of murine macrophages (J774A.
View Article and Find Full Text PDFJ Chromatogr B Analyt Technol Biomed Life Sci
August 2021
B lymphocytes ('B cells') are components of the human immune system with obvious potential for medical and biotechnological applications. Here, we discuss the isolation of primary human B cells from both juvenile and adult tonsillar material using a two-step procedure based on gradient centrifugation followed by separation on a nylon wool column as alternative to the current gold standard, i.e.
View Article and Find Full Text PDFPurpose: Complex regional pain syndrome (CRPS) type I, formerly known as reflex sympathetic dystrophy (RSD) or algodystrophy, is a condition with chronic pain condition following a trauma or surgery. The physiopathology of this syndrome remained incompletely known. Due to the lack of effective curative treatment, prevention of this complication is important.
View Article and Find Full Text PDFObjective: To examine measurement properties (inter-rater reliability, agreement, validity, and responsiveness) of the Cumulated Ambulation Score French translation in patients with hip fracture.
Design: Methodological study.
Setting: A 20-bed orthopedic unit and 20-bed geriatric unit.
Background: Magnetosomes produced by magnetotactic bacteria represent magnetic nanoparticles with unprecedented characteristics. However, their use in many biotechnological applications has so far been hampered by their challenging bioproduction at larger scales.
Results: Here, we developed an oxystat batch fermentation regime for microoxic cultivation of Magnetospirillum gryphiswaldense in a 3 L bioreactor.
Nonviral DNA vectors are promising alternatives to viral ones. Their use in DNA medicine is limited by an inability to transfect, for example, nondividing or suspension cells. In recent years, star-shaped synthetic polycationic vectors, so called "Nanostars", have shown some promise in this regard, at least when compared to the "gold standard" in nonviral vectors, namely, linear poly(ethyleneimine) (l-PEI).
View Article and Find Full Text PDFTemperature and salinity are important regulators of mangrove range limits and productivity, but the physiological responses of mangroves to the interactive effects of temperature and salinity remain uncertain. We tested the hypothesis that salinity alters photosynthetic responses to seasonal changes in temperature and vapor pressure deficit (D), as well as thermal acclimation _of leaf respiration in black mangrove (Avicennia germinans). To test this hypothesis, we grew seedlings of A.
View Article and Find Full Text PDFA major challenge in tissue engineering and artificial scaffolding is to combine easily tunable scaffolds biomimicking the extracellular matrix of native organs with delivery-controlled cell culturing to create fully cellularized, large artificial 3D scaffolds. Aiming at bioartificial liver construction, we present our research using galactose-functionalized, ultraporous polylactide 3D nanofiber sponges fabricated out of electrospun fibers. Sponge biomodification by blend galactosylation and in-solution coating is performed, respectively, using a polylactide-galactose carrier-copolymer that promotes cell delivery and features a pronounced autofluorescence.
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