Specifically designed and functionalized nanoparticles hold great promise for biomedical applications. Yet, the applicability of nanoparticles is critically predetermined by their surface functionalization and biodegradability. Here we demonstrate that amino-functionalized polystyrene nanoparticles (PS-NH2), but not amino- or hydroxyl-functionalized silica particles, trigger cell death in hepatocellular carcinoma Huh7 cells. Importantly, biodegradability of nanoparticles plays a crucial role in regulation of essential cellular processes. Thus, biodegradable silica nanoparticles having the same shape, size and surface functionalization showed opposite cellular effects in comparison with similar polystyrene nanoparticles. At the molecular level, PS-NH2 obstruct and amino-functionalized silica nanoparticles (Si-NH2) activate the mTOR signalling in Huh7 and HepG2 cells. PS-NH2 induced time-dependent lysosomal destabilization associated with damage of the mitochondrial membrane. Solely in PS-NH2-treated cells, permeabilization of lysosomes preceded cell death. Contrary, Si-NH2 nanoparticles enhanced proliferation of HuH7 and HepG2 cells. Our findings demonstrate complex cellular responses to functionalized nanoparticles and suggest that nanoparticles can be used to control activation of mTOR signaling with subsequent influence on proliferation and viability of HuH7 cells. The data provide fundamental knowledge which could help in developing safe and efficient nano-therapeutics.
- MeSH
- Adsorption MeSH
- Amines chemistry MeSH
- Carcinoma, Hepatocellular metabolism pathology MeSH
- Protein Conformation MeSH
- Lysosomes metabolism MeSH
- Cell Line, Tumor MeSH
- Liver Neoplasms metabolism pathology MeSH
- Nanoparticles chemistry MeSH
- Silicon Dioxide chemistry MeSH
- Permeability MeSH
- Polystyrenes chemistry MeSH
- Surface Properties MeSH
- Cell Proliferation MeSH
- Ribonucleases metabolism MeSH
- Serum Albumin, Bovine metabolism MeSH
- Signal Transduction * MeSH
- Cattle MeSH
- TOR Serine-Threonine Kinases metabolism MeSH
- Animals MeSH
- Check Tag
- Cattle MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
Five types of amide-amine Carbon Nano-Particles (CNPs) were prepared by functionalization of CNPs and characterized by several analytical methods. The successful grafting of amines on CNPs was verified by X-ray photoelectron spectroscopy (XPS), organic elemental analysis and electrokinetic analysis. The size and morphology of CNPs were determined from transmission electron microscopy. The surface area and porosity of CNPs were examined by adsorption and desorption isotherms. Differential scanning calorimetry was used to investigate thermal stability of CNPs. The amount of bonded amine depends on its dimensionality arrangement. Surface area and pore volumes of CNPs decrease several times after individual amino-compound grafting. Selected types of functionalized CNPs were grafted onto a plasma activated surface of HDPE. The successful grafting of CNPs on the polymer surface was verified by XPS. Wettability was determined by contact angle measurements. Surface morphology and roughness were studied by atomic force microscopy. A dramatic decrease of contact angle and surface morphology was observed on CNP grafted polymer surface. Cytocompatibility of modified surfaces was studied in vitro, by determination of adhesion, proliferation and viability of vascular smooth muscle cells (VSMCs). Grafting of CNPs onto the polymer surface has a positive effect on the adhesion, proliferation and viability of VSMCs.
- MeSH
- Amines chemistry MeSH
- Cells, Cultured MeSH
- Humans MeSH
- Myocytes, Smooth Muscle cytology drug effects MeSH
- Nanoparticles adverse effects chemistry MeSH
- Polyethylene chemistry MeSH
- Cell Proliferation drug effects MeSH
- Wettability MeSH
- Muscle, Smooth, Vascular cytology MeSH
- Carbon chemistry MeSH
- Cell Survival drug effects MeSH
- Animals MeSH
- Check Tag
- Humans MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
Nanogels represent a pivotal class of biomaterials in the therapeutic intracellular treatment of many diseases, especially those involving the central nervous system (CNS). Their biocompatibility and synergy with the biological environment encourage their cellular uptake, releasing the curative cargo in the desired area. As a main drawback, microglia are generally able to phagocytize any foreign element overcoming the blood brain barrier (BBB), including these materials, drastically limiting their bioavailability for the target cells. In this work, we investigated the opportunity to tune and therefore reduce nanogel internalization in microglia cultures, exploiting the orthogonal chemical functionalization with primary amine groups, as a surface coating strategy. Nanogels are designed by following two methods: the direct grafting of aliphatic primary amines and the linkage of -NH2 modified PEG on the nanogel surface. The latter synthesis was proposed to evaluate the combination of PEGylation with the basic nitrogen atom. The achieved results indicate the possibility of effectively modulating the uptake of nanogels, in particular limiting their internalization using the PEG-NH2 coating. This outcome could be considered a promising strategy for the development of carriers for drugs or gene delivery that could overcome microglia scavenging.
- MeSH
- Amines pharmacology MeSH
- Coated Materials, Biocompatible pharmacology MeSH
- Dynamic Light Scattering MeSH
- Endocytosis drug effects MeSH
- Fluorescence MeSH
- Microglia cytology drug effects MeSH
- Models, Molecular MeSH
- Mice, Inbred C57BL MeSH
- Nanogels chemistry MeSH
- Proton Magnetic Resonance Spectroscopy MeSH
- Spectroscopy, Fourier Transform Infrared MeSH
- Particle Size MeSH
- Cell Survival drug effects MeSH
- Animals MeSH
- Check Tag
- Animals MeSH
- Publication type
- Journal Article MeSH
The amine-binding properties of sand fly salivary yellow-related proteins (YRPs) were described only in Lutzomyia longipalpis sand flies. Here, we experimentally confirmed the kratagonist function of YRPs in the genus Phlebotomus. We utilized microscale thermophoresis technique to determine the amine-binding properties of YRPs in saliva of Phlebotomus perniciosus and P. orientalis, the Old-World vectors of visceral leishmaniases causative agents. Expressed and purified YRPs from three different sand fly species were tested for their interactions with various biogenic amines, including serotonin, histamine and catecholamines. Using the L. longipalpis YRP LJM11 as a control, we have demonstrated the comparability of the microscale thermophoresis method with conventional isothermal titration calorimetry described previously. By homology in silico modeling, we predicted the surface charge and both amino acids and hydrogen bonds of the amine-binding motifs to influence the binding affinities between closely related YRPs. All YRPs tested bound at least two biogenic amines, while the affinities differ both among and within species. Low affinity was observed for histamine. The salivary recombinant proteins rSP03B (P. perniciosus) and rPorASP4 (P. orientalis) showed high-affinity binding of serotonin, suggesting their capability to facilitate inhibition of the blood vessel contraction and platelet aggregation.
- MeSH
- Amines metabolism MeSH
- Insect Proteins metabolism MeSH
- Protein Conformation MeSH
- Phlebotomus metabolism MeSH
- Salivary Proteins and Peptides metabolism MeSH
- Salivary Glands metabolism MeSH
- Static Electricity MeSH
- Animals MeSH
- Check Tag
- Animals MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
- Research Support, N.I.H., Intramural MeSH
In this critical review, we outline various covalent and non-covalent approaches for the functionalization of iron oxide nanoparticles (IONPs). Tuning the surface chemistry and design of magnetic nanoparticles are described in relation to their applicability in advanced medical technologies and biotechnologies including magnetic resonance imaging (MRI) contrast agents, targeted drug delivery, magnetic separations and immobilizations of proteins, enzymes, antibodies, targeting agents and other biosubstances. We review synthetic strategies for the controlled preparation of IONPs modified with frequently used functional groups including amine, carboxyl and hydroxyl groups as well as the preparation of IONPs functionalized with other species, e.g., epoxy, thiol, alkane, azide, and alkyne groups. Three main coupling strategies for linking IONPs with active agents are presented: (i) chemical modification of amine groups on the surface of IONPs, (ii) chemical modification of bioactive substances (e.g. with fluorescent dyes), and (iii) the activation of carboxyl groups mainly for enzyme immobilization. Applications for drug delivery using click chemistry linking or biodegradable bonds are compared to non-covalent methods based on polymer modified condensed magnetic nanoclusters. Among many challenges, we highlight the specific surface engineering allowing both therapeutic and diagnostic applications (theranostics) of IONPs and magnetic/metallic hybrid nanostructures possessing a huge potential in biocatalysis, green chemistry, magnetic bioseparations and bioimaging.
A dual-mode functional chip for chiral sensing based on mobile phone wettability measurements and portable surface-enhanced Raman spectroscopy (SERS) is reported. The plasmon-active regular gold grating surface was covalently grafted with chiral recognition moieties, l- or d-enantiomers of tartaric acid, making stereoselective discrimination of chiral amines possible. Chiral sensing of amines includes two modes of analysis, performed subsequently on the one chip surface with portable instruments (mobile phone equipped with a camera and developed application (app) Dropangle and a portable Raman spectrometer). First, the wettability changes, caused by enantioselective entrapping of chiral amines, are monitored and analyzed via our mobile phone app, allowing detection of the optical configuration and concentration of enantiomers with 1 order of magnitude accuracy. Second, SERS measurement on the same chip provides information about the chemical structure of entrapped amines and allows calculation of the enantiomeric excess with great accuracy. The applicability of the developed chip is demonstrated on a variety of chiral amines, including tyrosine, cysteine, dopamine (DOPA), and dextromethorphan in analytical solutions and in commercially available DOPA-containing drug. Moreover, we demonstrate that the chips could be regenerated and used repeatedly for at least five cycles.
Regeneration of large bone defects caused by trauma or tumor resection remains one of the biggest challenges in orthopedic surgery. Because of the limited availability of autograft material, the use of artificial bone is prevalent; however, the primary role of currently available artificial bone is restricted to acting as a bone graft extender owing to the lack of osteogenic ability. To explore whether surface modification might enhance artificial bone functionality, in this study we applied low-pressure plasma technology as next-generation surface treatment and processing strategy to chemically (amine) modify the surface of beta-tricalcium phosphate (β-TCP) artificial bone using a CH4/N2/He gas mixture. Plasma-treated β-TCP exhibited significantly enhanced hydrophilicity, facilitating the deep infiltration of cells into interconnected porous β-TCP. Additionally, cell adhesion and osteogenic differentiation on the plasma-treated artificial bone surfaces were also enhanced. Furthermore, in a rat calvarial defect model, the plasma treatment afforded high bone regeneration capacity. Together, these results suggest that amine modification of artificial bone by plasma technology can provide a high osteogenic ability and represents a promising strategy for resolving current clinical limitations regarding the use of artificial bone.
- MeSH
- Biocompatible Materials metabolism MeSH
- Cell Differentiation physiology MeSH
- Calcium Phosphates metabolism MeSH
- Bone Substitutes metabolism therapeutic use MeSH
- Rats MeSH
- Osteogenesis physiology MeSH
- Bone Regeneration physiology MeSH
- Bone Transplantation methods MeSH
- Animals MeSH
- Check Tag
- Rats MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
Úvod: Protilátky proti membránovým a synaptickým antigenům jsou přímo patogenní protilátky sdružené s pestrou paletou neurologických syndromů. Různorodost příznaků komplikuje stanovení diagnózy, a tím i včasné zahájení imunoterapie. Cíl: Cílem práce bylo popsat klinické charakteristiky pacientů s pozitivitou uvedených protilátek. Metodika a soubor: V období dvou let jsme zjišťovali přítomnost protilátek proti membránovým a synaptickým antigenům u 224 pacientů. Metodou nepřímé imunofluorescence byly vyšetřeny protilátky proti N‑metyl‑D‑aspartátovému receptoru (anti‑NMDAR), α‑amino‑3-hydroxy‑5-metyl‑4-izoxazolepropionátovému receptoru (anti‑AMPAR 1 a 2), B‑receptoru kyseliny γ‑aminomáselné (anti‑GABABR), proti leucin‑rich‑glioma‑inactivated proteinu‑1 (anti‑LGI1) a proti contactin‑associated proteinu‑2 (anti‑CASPR2). U pozitivních pacientů byly retrospektivně zhodnoceny klinické projevy, nálezy pomocných metod a vývoj onemocnění. Pacienti s pozitivitou anti‑NMDAR protilátek nebyli do hodnocení zahrnuti. Výsledky: Autoprotilátky byly prokázány v séru 11 pacientů (medián 58 let, sedm mužů) – u šesti pacientů anti‑LGI1, u čtyř anti‑CASPR2, u dvou anti‑AMPAR1 (u jednoho pacienta současně anti‑AMPAR1 a anti‑CASPR2). Příznaky zahrnovaly epilepsii (n = 5), subakutní encefalopatii (n = 5), doprovázenou ve čtyřech případech epileptickými záchvaty, a mozečkový syndrom s doprovodným kognitivním deficitem (n = 1). U dvou pacientů byly současně přítomny dobře charakterizované onkoneurální protilátky (anti‑Hu, anti‑Ma2). Nádor (malobuněčný karcinom plic) byl zjištěn u jedné pacientky (anti‑AMPAR1). U osmi pacientů došlo po podání imunosuprese k remisi nebo částečnému zlepšení klinického stavu. Závěr: Přítomnost protilátek proti membránovým antigenům je sdružena nejčastěji s limbickou encefalitidou nebo fokální epilepsií, vzácněji s jinými neurologickými syndromy. Efekt imunoterapie závisí na jejím časném podání.
Background: Neuronal surface antibodies are associated with numerous neurological symptoms. Better knowledge of these symptoms may improve identification of potential candidates for immunotherapy. Aim: Characterize clinical signs in patients with neuronal surface antibodies positivity. Methods: We detected neuronal surface antibodies in 11/2011–12/2013 in 224 patients (224 in serum and 37 in cerebrospinal fluid). We investigated anti-NMDAR, anti-AMPAR1, anti-AMPAR2, anti-GABABR, anti-LGI1, anti-CASPR2 using cell-based assays for indirect immunofluorescence (Euroimmun AG). We retrospectively analyzed clinical characteristics of patients with positive neuronal surface antibodies in serum or cerebrospinal fluid other than anti-NMDAR positive patients. Results: Neuronal surface antibodies were detected in 11 patients (seven males, median age 58). Six patients had anti-LGI1, four anti-CASPR2 and two anti-AMPAR1 antibodies (one patient had both anti-CASPR2 and anti-AMPAR1 antibodies). Clinical symptoms included chronic epilepsy (n = 5), acute encephalopathy (n = 5) accompanied by epileptic seizures in four patients and one patient presented with cerebellar syndrome and cognitive deficit. Two patients had coincidence of paraneoplastic antibodies (anti-Hu, anti-Ma2). Tumor (small cell lung carcinoma) was diagnosed in one patient (anti-AMPAR1). Eight patients improved following immunotherapy (corticosteroids, IVIG). Early immunotherapy was associated with better outcome. Conclusion: NS-Abs were mostly associated with limbic encephalitis and chronic temporal lobe epilepsy. Immunotherapy had better effect when applied early in the disease course. Key words: autoimmune diseases – encephalitis – antibodies to cell-surface proteins – limbic encephalitis The authors declare they have no potential conflicts of interest concerning drugs, products, or services used in the study. The Editorial Board declares that the manuscript met the ICMJE “uniform requirements” for biomedical papers.
- MeSH
- Autoimmune Diseases MeSH
- Autoantibodies * blood MeSH
- Adult MeSH
- Electroencephalography MeSH
- Anti-N-Methyl-D-Aspartate Receptor Encephalitis blood MeSH
- Epilepsies, Partial diagnosis drug therapy MeSH
- Fluorescent Antibody Technique, Indirect MeSH
- Receptors, Glutamate analysis MeSH
- Immunosuppressive Agents administration & dosage MeSH
- Cognition Disorders etiology MeSH
- Middle Aged MeSH
- Humans MeSH
- Limbic Encephalitis * diagnosis drug therapy MeSH
- Magnetic Resonance Imaging MeSH
- Membrane Proteins * blood MeSH
- Brain radiography MeSH
- Brain Diseases * blood radiography MeSH
- Memory Disorders etiology MeSH
- Nerve Tissue Proteins analysis MeSH
- Proteins analysis MeSH
- Receptors, GABA-B analysis MeSH
- Receptors, N-Methyl-D-Aspartate analysis MeSH
- Aged MeSH
- Check Tag
- Adult MeSH
- Middle Aged MeSH
- Humans MeSH
- Male MeSH
- Aged MeSH
- Female MeSH
- Publication type
- Research Support, Non-U.S. Gov't MeSH
Cytokinins are mobile multifunctional plant hormones with roles in development and stress resilience. Although their Histidine Kinase receptors are substantially localised to the endoplasmic reticulum, cellular sites of cytokinin perception and importance of spatially heterogeneous cytokinin distribution continue to be debated. Here we show that cytokinin perception by plasma membrane receptors is an effective additional path for cytokinin response. Readout from a Two Component Signalling cytokinin-specific reporter (TCSn::GFP) closely matches intracellular cytokinin content in roots, yet we also find cytokinins in extracellular fluid, potentially enabling action at the cell surface. Cytokinins covalently linked to beads that could not pass the plasma membrane increased expression of both TCSn::GFP and Cytokinin Response Factors. Super-resolution microscopy of GFP-labelled receptors and diminished TCSn::GFP response to immobilised cytokinins in cytokinin receptor mutants, further indicate that receptors can function at the cell surface. We argue that dual intracellular and surface locations may augment flexibility of cytokinin responses.
- MeSH
- Adenine analogs & derivatives pharmacology MeSH
- Arabidopsis cytology drug effects genetics metabolism MeSH
- Cytokinins metabolism MeSH
- Extracellular Fluid metabolism MeSH
- Plants, Genetically Modified MeSH
- Histidine Kinase genetics metabolism MeSH
- Mutation MeSH
- Arabidopsis Proteins genetics metabolism MeSH
- Recombinant Proteins genetics metabolism MeSH
- Signal Transduction MeSH
- Green Fluorescent Proteins genetics metabolism MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
The presence of biogenic amines is a hallmark of degraded food and its products. Herein, we focused on the utilization of magnetic nanoparticles off-line coupled with ion exchange chromatography with post-column ninhydrin derivatization and Vis detection for histamine (Him) separation and detection. Primarily, we described the synthesis of magnetic nanoparticles with nanomaghemite core (γ-Fe₂O₃) functionalized with titanium dioxide and, then, applied these particles to specific isolation of Him. To obtain further insight into interactions between paramagnetic particles' (PMP) surface and Him, a scanning electron microscope was employed. It was shown that binding of histamine causes an increase of relative current response of deprotonated PMPs, which confirmed formation of Him-PMPs clusters. The recovery of the isolation showed that titanium dioxide-based particles were able to bind and preconcentrate Him with recovery exceeding 90%. Finally, we successfully carried out the analyses of real samples obtained from silage. We can conclude that our modified particles are suitable for Him isolation, and thus may serve as the first isolation step of Him from biological samples, as it is demonstrated on alfalfa seed variety Tereza silage.
