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1.
Antioxidants (Basel) ; 13(6)2024 Jun 09.
Article in English | MEDLINE | ID: mdl-38929145

ABSTRACT

α-lipoic acid is a naturally occurring compound with potent antioxidant properties that helps protect cells and tissues from oxidative stress. Its incorporation into nanoplatforms can affect factors like bioavailability, stability, reactivity, and targeted delivery. Nanoformulations of α-lipoic acid can significantly enhance its solubility and absorption, making it more bioavailable. While α-lipoic acid can be prone to degradation in its free form, encapsulation within nanoparticles ensures its stability over time, and its release in a controlled and sustained manner to the targeted tissues and cells. In addition, α-lipoic acid can be combined with other compounds, such as other antioxidants, drugs, or nanomaterials, to create synergistic effects that enhance their overall therapeutic benefits or hinder their potential cytotoxicity. This review outlines the advantages and drawbacks associated with the use of α-lipoic acid, as well as various nanotechnological approaches employed to enhance its therapeutic effectiveness, whether alone or in combination with other bioactive agents. Furthermore, it describes the engineering of α-lipoic acid to produce poly(α-lipoic acid) nanoparticles, which hold promise as an effective drug delivery system.

3.
Nat Commun ; 14(1): 7013, 2023 Nov 14.
Article in English | MEDLINE | ID: mdl-37963921

ABSTRACT

Earth's atmosphere, whose ionization stability plays a fundamental role for the evolution and endurance of life, is exposed to the effect of cosmic explosions producing high energy Gamma-ray-bursts. Being able to abruptly increase the atmospheric ionization, they might deplete stratospheric ozone on a global scale. During the last decades, an average of more than one Gamma-ray-burst per day were recorded. Nevertheless, measurable effects on the ionosphere were rarely observed, in any case on its bottom-side (from about 60 km up to about 350 km of altitude). Here, we report evidence of an intense top-side (about 500 km) ionospheric perturbation induced by significant sudden ionospheric disturbance, and a large variation of the ionospheric electric field at 500 km, which are both correlated with the October 9, 2022 Gamma-ray-burst (GRB221009A).

4.
J Control Release ; 356: 115-129, 2023 04.
Article in English | MEDLINE | ID: mdl-36841287

ABSTRACT

The complement system, professional phagocytes and other cells such as Natural killer cells and mast cells are among the important components of the innate arm of the immune system. These constituents provide an orchestrated array of defences and responses against tissue injury and foreign particles, including nanopharmaceuticals. While interception of nanopharmaceuticals by the immune system is beneficial for immunomodulation and treatment of phagocytic cell disorders, it is imperative to understand the multifaceted mechanisms by which nanopharmaceuticals interacts with the immune system and evaluate the subsequent balance of beneficial versus adverse reactions. An example of the latter is adverse infusion reactions to regulatory-approved nanopharmaceuticals seen in human subjects. Here, we discuss collective opinions and findings from our laboratories in mapping nanoparticle-mediated complement and leucocyte/macrophage responses.


Subject(s)
Nanoparticles , Phagocytes , Humans , Macrophages , Complement System Proteins , Leukocytes , Nanoparticles/adverse effects , Phagocytosis
5.
Nanomedicine ; 45: 102593, 2022 09.
Article in English | MEDLINE | ID: mdl-35907619

ABSTRACT

Pluronic-coated polylipoic acid-based nanoparticles (F127@PLA-NPs) have great potential as biodegradable nanovectors for delivering active molecules to different organs in complex diseases. In this study we describe the in vivo biodistribution, safety and ability to deliver molecules of F127@PLA-NPs in healthy rats following intravenous administration. Adult rats were injected with 10 mg/kg of rhodamine B-labeled F127@PLA-NPs, and NPs fluorescence and MFI rate were measured by confocal microscopy in whole collected organs. The NPs accumulation rate was maximal in the heart, compared to the other organs. At the cellular level, myocytes and kidney tubular cells showed the highest NPs uptake. Neither histopathological lesion nor thrombogenicity were observed after NPs injection. Finally, F127@PLA-NPs were tested in vitro as miRNAs delivery nanosystem, and they showed good ability in targeting cardiomyocytes. These results demonstrated that our F127@PLA-NPs constitute a biological, minimally invasive and safe delivery tool targeting organs and cells, such as heart and kidney.


Subject(s)
MicroRNAs , Nanoparticles , Thioctic Acid , Animals , Drug Carriers , Poloxamer , Polyesters , Polyethylenes , Polypropylenes , Rats , Tissue Distribution
6.
Antioxidants (Basel) ; 11(5)2022 May 05.
Article in English | MEDLINE | ID: mdl-35624771

ABSTRACT

The control of radical damage and oxidative stress, phenomena involved in a large number of human pathologies, is a major pharmaceutical and medical goal. We here show that two biocompatible formulations of Pluronic-stabilized, poly (lipoic acid)-based nanoparticles (NP) effectively antagonized the formation of radicals and reactive oxygen species (ROS). These NPs, not only intrinsically scavenged radicals in a-cellular DPPH/ABTS assays, but also inhibited the overproduction of ROS induced by tert-Butyl hydroperoxide (t-BHP) in tumor cells (HeLa), human macrophages and neonatal rat ventricular myocytes (NRVMs). NPs were captured by macrophages and cardiomyocytes much more effectively as compared to HeLa cells and non-phagocytic leukocytes, eventually undergoing intracellular disassembly. Notably, NPs decreased the mitochondrial ROS generation induced by simulated Ischemia/Reperfusion Injury (IRI) in isolated cardiomyocytes. NPs also prevented IRI-triggered cardiomyocyte necrosis, mitochondrial dysfunction, and alterations of contraction-related intracellular Ca2+ waves. Hence, NPs appear to be an effective and cardiomyocyte-selective drug to protect against damages induced by post-ischemic reperfusion.

7.
Biomacromolecules ; 22(2): 467-480, 2021 02 08.
Article in English | MEDLINE | ID: mdl-33347750

ABSTRACT

Herein we present an innovative approach to produce biocompatible, degradable, and stealth polymeric nanoparticles based on poly(lipoic acid), stabilized by a PEG-ended surfactant. Taking advantage of the well-known thiol-induced polymerization of lipoic acid, a universal and nontoxic nanovector consisted of a solid cross-linked polymeric matrix of lipoic acid monomers was prepared and loaded with active species with a one-step protocol. The biological studies demonstrated a high stability in biological media, the virtual absence of "protein" corona in biological fluids, the absence of acute toxicity in vitro and in vivo, complete clearance from the organism, and a relevant preference for short-term accumulation in the heart. All these features make these nanoparticles candidates as a promising tool for nanomedicine.


Subject(s)
Nanoparticles , Protein Corona , Thioctic Acid , Nanomedicine , Polyethylene Glycols , Polymers
8.
Front Immunol ; 11: 567365, 2020.
Article in English | MEDLINE | ID: mdl-33154748

ABSTRACT

Understanding the effects mediated by a set of nanoparticle (NP)-bound host biomolecules, often indicated with the umbrella term of NP corona, is essential in nanomedicine, nanopharmacology, and nanotoxicology. Among the NP-adsorbed proteome, some factors mediate cell binding, endocytosis, and clearing by macrophages and other phagocytes (opsonins), while some others display few affinities for the cell surface (dysopsonins). The functional mapping of opsonins and dysopsonins is instrumental to design long-circulating and nanotoxicologically safe next-generation nanotheranostics. In this review, we critically analyze functional data identifying specific proteins with opsonin or dysopsonin properties. Special attention is dedicated to the following: (1) the simplicity or complexity of the NP proteome and its modulation, (2) the role of specific host proteins in mediating the stealth properties of uncoated or polymer-coated NPs, and (3) the ability of the innate immune system, and, in particular, of the complement proteins, to mediate NP clearance by phagocytes. Emerging species-specific peculiarities, differentiating humans from preclinical animal models (the murine especially), are highlighted throughout this overview. The operative definition of opsonin and dysopsonin and the measurement schemes to assess their in vitro efficacy is critically re-examined. This provides a shared and unbiased approach useful for NP opsonin and dysopsonin systematic identification.


Subject(s)
Nanoparticles , Opsonin Proteins/immunology , Theranostic Nanomedicine , Animals , Carrier Proteins , Complement System Proteins/immunology , Complement System Proteins/metabolism , Guidelines as Topic , Humans , Immunomodulation , Macrophages/immunology , Macrophages/metabolism , Nanoparticles/chemistry , Opsonin Proteins/administration & dosage , Opsonin Proteins/chemistry , Phagocytes/immunology , Phagocytes/metabolism , Protein Binding , Proteome , Theranostic Nanomedicine/methods
9.
Adv Drug Deliv Rev ; 157: 83-95, 2020.
Article in English | MEDLINE | ID: mdl-32389761

ABSTRACT

Considering the multifaceted protective and homeostatic roles of the complement system, many consequences arise when drug carriers, and particulate pharmaceutical formulations clash with complement proteins, and trigger complement cascade. Complement activation may induce formulation destabilization, promote opsonization, and affect biological and therapeutic performance of pharmaceutical nano- and micro-particles. In some cases, complement activation is beneficial, where complement may play a role in prophylactic protection, whereas uncontrolled complement activation is deleterious, and contributes to disease progression. Accordingly, design initiatives with particulate medicines should consider complement activation properties of the end formulation within the context of administration route, dosing, systems biology, and therapeutic perspective. Here we examine current progress in mechanistic processes underlying complement activation by pre-clinical and clinical particles, identify opportunities and challenges ahead, and suggest future directions in nanomedicine-complement interface research.


Subject(s)
Complement Activation/drug effects , Complement System Proteins/metabolism , Drug Carriers/chemistry , Animals , Humans , Microspheres , Nanoparticles , Pharmaceutical Preparations/administration & dosage , Pharmaceutical Preparations/metabolism
10.
Int J Pharm ; 566: 541-548, 2019 Jul 20.
Article in English | MEDLINE | ID: mdl-31173801

ABSTRACT

The effect of mild hyperthermia (MHT) on nanoparticle (NP) accumulation in rat model liver metastasis and the contribution of neoplastic and non-neoplastic cells were characterized. CdSe/ZnS QD-doped poly(lactic-co-glycolic acid) (PLGA) NPs (155 ±â€¯10 nm) were delivered via the ileocolic vein to metastatic livers 15 min after localized MW irradiation (1 min, 41 °C) or in normothermia (37 °C, NT). Quantitative analysis of tissue sections by confocal fluorescence microscopy 1 h after NP injection showed no NP tumor accumulation in NT. On the contrary, MHT increased NP association with tumor, compared to normal tissue. Counterstaining of specific markers showed that the MHT effect is due to an increased NP endocytosis not only by tumor cells, but also by hepatocytes at the growing tumor edge and, to a minor extent, by tumor-associated macrophages. High-NP capturing hepatocytes, close to the tumor, may be a relevant phenomenon in MHT-induced increased targeting of NPs to liver metastasis, influencing their therapeutic efficacy.


Subject(s)
Drug Carriers/administration & dosage , Hepatocytes/metabolism , Hyperthermia, Induced , Liver Neoplasms/metabolism , Nanoparticles/administration & dosage , Polylactic Acid-Polyglycolic Acid Copolymer/administration & dosage , Animals , Cadmium Compounds/administration & dosage , Colonic Neoplasms/metabolism , Colonic Neoplasms/pathology , Kupffer Cells/metabolism , Liver Neoplasms/secondary , Macrophages/metabolism , Male , Rats , Selenium Compounds/administration & dosage , Sulfides/administration & dosage , Zinc Compounds/administration & dosage
11.
Front Chem ; 7: 168, 2019.
Article in English | MEDLINE | ID: mdl-30984740

ABSTRACT

Fluorescence is a powerful tool for mapping biological events in real-time with high spatial resolution. Ultra-bright probes are needed in order to achieve high sensitivity: these probes are typically obtained by gathering a huge number of fluorophores in a single nanoparticle (NP). Unfortunately this assembly produces quenching of the fluorescence because of short-range intermolecular interactions. Here we demonstrate that rational structural modification of a well-known molecular fluorophore N-(7-nitrobenz-2-oxa-1,3-diazol-4-yl) (NBD) produces fluorophores that self-assemble in nanoparticles in the biocompatible environment without any dramatic decrease of the fluorescence quantum yield. Most importantly, the resulting NP show, in an aqueous environment, a brightness which is more than six orders of magnitude higher than the molecular component in the organic solvent. Moreover, the NP are prepared by nanoprecipitation and they are stabilized only via non-covalent interaction, they are surprisingly stable and can be observed as individual bright spots freely diffusing in solution at a concentration as low as 1 nM. The suitability of the NP as biocompatible fluorescent probes was demonstrated in the case of HeLa cells by fluorescence confocal microscopy and MTS assays.

12.
ACS Nano ; 12(6): 5834-5847, 2018 06 26.
Article in English | MEDLINE | ID: mdl-29750504

ABSTRACT

Poly(2-methyl-2-oxazoline) (PMOXA) is an alternative promising polymer to poly(ethylene glycol) (PEG) for design and engineering of macrophage-evading nanoparticles (NPs). Although PMOXA-engineered NPs have shown comparable pharmacokinetics and in vivo performance to PEGylated stealth NPs in the murine model, its interaction with elements of the human innate immune system has not been studied. From a translational angle, we studied the interaction of fully characterized PMOXA-coated vinyltriethoxysilane-derived organically modified silica NPs (PMOXA-coated NPs) of approximately 100 nm in diameter with human complement system, blood leukocytes, and macrophages and compared their performance with PEGylated and uncoated NP counterparts. Through detailed immunological and proteomic profiling, we show that PMOXA-coated NPs extensively trigger complement activation in human sera exclusively through the classical pathway. Complement activation is initiated by the sensing molecule C1q, where C1q binds with high affinity ( Kd = 11 ± 1 nM) to NP surfaces independent of immunoglobulin binding. C1q-mediated complement activation accelerates PMOXA opsonization with the third complement protein (C3) through the amplification loop of the alternative pathway. This promoted NP recognition by human blood leukocytes and monocyte-derived macrophages. The macrophage capture of PMOXA-coated NPs correlates with sera donor variability in complement activation and opsonization but not with other major corona proteins, including clusterin and a wide range of apolipoproteins. In contrast to these observations, PMOXA-coated NPs poorly activated the murine complement system and were marginally recognized by mouse macrophages. These studies provide important insights into compatibility of engineered NPs with elements of the human innate immune system for translational steps.


Subject(s)
Complement Activation , Complement C1q/immunology , Complement C3/immunology , Nanoparticles/metabolism , Opsins/immunology , Phagocytes/immunology , Polyamines/metabolism , Silicon Dioxide/immunology , Animals , Complement C1q/chemistry , Complement C3/chemistry , Female , Humans , Immunity, Innate/immunology , Male , Mice , Mice, Inbred BALB C , Nanoparticles/chemistry , Opsins/chemistry , Phagocytes/chemistry , Polyamines/chemistry , Polyamines/immunology , Silicon Dioxide/chemistry
13.
Clin Vaccine Immunol ; 24(10)2017 Oct.
Article in English | MEDLINE | ID: mdl-28835358

ABSTRACT

Dendritic cells (DCs) regulate the host-microbe balance in the gut and skin, tissues likely exposed to nanoparticles (NPs) present in drugs, food, and cosmetics. We analyzed the viability and the activation of DCs incubated with extracellular media (EMs) obtained from cultures of commensal bacteria (Escherichia coli, Staphylococcus epidermidis) or pathogenic bacteria (Pseudomonas aeruginosa, Staphylococcus aureus) in the presence of amorphous silica nanoparticles (SiO2 NPs). EMs and NPs synergistically increased the levels of cytotoxicity and cytokine production, with different nanoparticle dose-response characteristics being found, depending on the bacterial species. E. coli and S. epidermidis EMs plus NPs at nontoxic doses stimulated the secretion of interleukin-1ß (IL-1ß), IL-12, IL-10, and IL-6, while E. coli and S. epidermidis EMs plus NPs at toxic doses stimulated the secretion of gamma interferon (IFN-γ), tumor necrosis factor alpha (TNF-α), IL-4, and IL-5. On the contrary, S. aureus and P. aeruginosa EMs induced cytokines only when they were combined with NPs at toxic concentrations. The induction of maturation markers (CD86, CD80, CD83, intercellular adhesion molecule 1, and major histocompatibility complex class II) by commensal bacteria but not by pathogenic ones was improved in the presence of noncytotoxic SiO2 NP doses. DCs consistently supported the proliferation and differentiation of CD4+ and CD8+ T cells secreting IFN-γ and IL-17A. The synergistic induction of CD86 was due to nonprotein molecules present in the EMs from all bacteria tested. At variance with this finding, the synergistic induction of IL-1ß was prevalently mediated by proteins in the case of E. coli EMs and by nonproteins in the case of S. epidermidis EMs. A bacterial costimulus did not act on DCs after adsorption on SiO2 NPs but rather acted as an independent agonist. The inflammatory and immune actions of DCs stimulated by commensal bacterial agonists might be altered by the simultaneous exposure to engineered or environmental NPs.


Subject(s)
Cell Survival/drug effects , Culture Media/pharmacology , Dendritic Cells/drug effects , Dendritic Cells/immunology , Nanoparticles/adverse effects , Silicon Dioxide/adverse effects , Symbiosis , Antigens, CD/genetics , Cell Differentiation/drug effects , Culture Media/chemistry , Cytokines/biosynthesis , Cytokines/immunology , Dendritic Cells/physiology , Escherichia coli/drug effects , Escherichia coli/physiology , Humans , Interferon-gamma/immunology , Interferon-gamma/metabolism , Interleukin-10/biosynthesis , Interleukin-10/immunology , Interleukin-1beta/immunology , Interleukin-1beta/metabolism , Interleukin-4/biosynthesis , Interleukin-4/immunology , Nanoparticles/chemistry , Pseudomonas aeruginosa/drug effects , Pseudomonas aeruginosa/pathogenicity , Pseudomonas aeruginosa/physiology , Silicon Dioxide/pharmacology , Staphylococcus aureus/drug effects , Staphylococcus aureus/pathogenicity , Staphylococcus aureus/physiology , Staphylococcus epidermidis/drug effects , Staphylococcus epidermidis/physiology
14.
ChemMedChem ; 12(4): 337-345, 2017 02 20.
Article in English | MEDLINE | ID: mdl-28067470

ABSTRACT

Some hybrid foldamers of various length, all containing the (4R,5S)-4-carboxy-5-methyloxazolidin-2-one (d-Oxd) moiety alternating with an l-amino acid (l-Val, l-Lys, or l-Ala), were prepared in order to study their preferred conformations and to evaluate their biological activity. Surprisingly, only the longer oligomers containing l-Ala fold into well-established helices, whereas all the other oligomers give partially unfolded turn structures. Nevertheless, they all show good biocompatibility, with no detrimental effects up to 64 µm. After equipping some selected foldamers with the fluorescent tag rhodamine B, a quantitative analysis was performed by dose- and time-response fluorescence-activated cell sorting (FACS) assays with human HeLa cells and primary blood lymphocytes, granulocytes, and monocytes. Among the cell types analyzed, the oligomers associated with monocytes and granulocytes with greatest efficacy, still visible after 24 h incubation. This effect is even more pronounced for foldamers that are able to form stable helices.


Subject(s)
Biocompatible Materials/pharmacology , Granulocytes/drug effects , Monocytes/drug effects , Peptoids/pharmacology , Amino Acids/chemistry , Biocompatible Materials/chemical synthesis , Biocompatible Materials/chemistry , Cell Survival/drug effects , Cells, Cultured , Circular Dichroism , Crystallography, X-Ray , Granulocytes/cytology , Granulocytes/metabolism , HeLa Cells , Humans , Microscopy, Confocal , Molecular Conformation , Monocytes/cytology , Monocytes/metabolism , Peptoids/chemical synthesis , Peptoids/chemistry
15.
Data Brief ; 6: 359-67, 2016 Mar.
Article in English | MEDLINE | ID: mdl-26862583

ABSTRACT

Peptaibiotics are a group of membrane active peptides of fungal origin. They typically contain α-aminoisobutyric acid (Aib; 1-letter code, U) and other non-coded residues (Toniolo and Brückner, 2009; Neumann et al., 2015; Benedett et al., 1982) [1], [2], [3] stabilizing their helical structure. Peptaibols are peptaibiotics carrying a 1, 2-aminoalcohol at the C-terminus. When a fatty acid chain (of 8-10 carbon atoms) is present at their N-terminus, they are called lipopeptaibols (Toniolo et al., 2001; Degenkolb et al., 2003) [4], [5]. We found (Tavano et al., 2015) [6] that the lipopeptaibol trichogin displays no antibacterial effects up to 64 µM, against both Gram(-) and Gram(+) bacteria, but kills tumor and healthy human cells via a mechanism requiring both the C-terminal primary alcohol group and the N-terminal n-octanoyl moiety, with EC50s around 4-5 µM. However, the substitution of single Gly residues with Lys strongly improves anti-Gram(+) activity (Tavano et al., 2015; De Zotti, Biondi, Park et al., 2012; De Zotti, Biondi, Peggion et al., 2012) [6], [7], [8]. To further characterize the activity of trichogin analogs as antibiotics and cytotoxic agents, we here manipulated the peptide helix amphipathicity by means of two different substitutions: (i) Aib to Leu (De Zotti et al., 2012) [7] or (ii) multiple Gly to Lys changes (Tavano et al., 2015; De Zotti, Biondi, Park et al., 2012; De Zotti, Biondi, Peggion, Formaggio et al., 2012; De Zotti, Biondi, Peggion, De Poli et al., 2012) [6], [7], [8], [9]. The antibacterial activity against four commensal or opportunistic bacterial species and the cytotoxicity against a panel of 9 healthy and tumor-derived eukaryotic cell types (including erythrocytes) are reported as MIC and EC50 (MTS - [3-(4, 5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)]-2H-tetrazolium- reduction and LDH - lactate dehydrogenase - release assay).

16.
Int J Biochem Cell Biol ; 75: 148-61, 2016 06.
Article in English | MEDLINE | ID: mdl-26748245

ABSTRACT

Protein adsorption to nanoparticles is described as a chemical reaction in which proteins attach to binding sites on the nanoparticle surface. This process is defined by a dissociation coefficient, which tells how many proteins are adsorbed per nanoparticle in dependence of the protein concentration. Different techniques to experimentally determine dissociation coefficients of protein adsorption to nanoparticles are reviewed. Results of more than 130 experiments in which dissociation coefficients have been determined are compared. Data show that different methods, nanoparticle systems, and proteins can lead to significantly different dissociation coefficients. However, we observed a clear tendency of smaller dissociation coefficients upon less negative towards more positive zeta potentials of the nanoparticles. The zeta potential thus is a key parameter influencing protein adsorption to the surface of nanoparticles. Our analysis highlights the importance of the characterization of the parameters governing protein-nanoparticle interaction for quantitative evaluation and objective literature comparison.


Subject(s)
Chemistry Techniques, Analytical/methods , Nanoparticles/chemistry , Protein Corona/chemistry , Adsorption , Animals , Humans
17.
Article in English | MEDLINE | ID: mdl-29942377

ABSTRACT

We tested whether amorphous SiO2-NPs and formylpeptide receptor (FPRs) agonists synergistically activate human monocytes and neutrophil polymorphonuclear granulocytes (PMNs). Peptide ligands specifically binding to FPR1 (f-MLP) and to FPR2 (MMK-1, WKYMVM and WKYMVm) human isoforms did not modify the association of SiO2-NPs to both cell types or their cytotoxic effects. Similarly, the extent of CD80, CD86, CD83, ICAM-1 and MHCII expression in monocytes treated with SiO2-NPs was not significantly altered by any FPRs agonist. However, FPR1 stimulation with f-MLP strongly increased the secretion of IL-1ß, IL-6 and IL-8 by human monocytes, and of IL-8 by PMNs in the presence of SiO2-NPs, due to the synergic stimulation of gene transcription. FPR2 agonists also up-modulated the production of IL-1ß induced by monocytes treated with SiO2-NPs. In turn, SiO2-NPs increased the chemotaxis of PMNs toward FPR1-specific ligands, but not toward FPR2-specific ones. Conversely, the chemotaxis of monocytes toward FPR2-specific peptides was inhibited by SiO2-NPs. NADPH-oxidase activation triggered by FPR1- and FPR2-specific ligands in both cell types was not altered by SiO2-NPs. Microbial and tissue danger signals sensed by FPRs selectively amplified the functional responses of monocytes and PMNS to SiO2-NPs, and should be carefully considered in the assessment of the risk associated with nanoparticle exposure.

18.
Nanoscale ; 7(42): 17710-28, 2015 Nov 14.
Article in English | MEDLINE | ID: mdl-26451907

ABSTRACT

A coat of strongly-bound host proteins, or hard corona, may influence the biological and pharmacological features of nanotheranostics by altering their cell-interaction selectivity and macrophage clearance. With the goal of identifying specific corona-effectors, we investigated how the capture of amorphous silica nanoparticles (SiO2-NPs; Ø = 26 nm; zeta potential = -18.3 mV) by human lymphocytes, monocytes and macrophages is modulated by the prominent proteins of their plasma corona. LC MS/MS analysis, western blotting and quantitative SDS-PAGE densitometry show that Histidine Rich Glycoprotein (HRG) is the most abundant component of the SiO2-NP hard corona in excess plasma from humans (HP) and mice (MP), together with minor amounts of the homologous Kininogen-1 (Kin-1), while it is remarkably absent in their Foetal Calf Serum (FCS)-derived corona. HRG binds with high affinity to SiO2-NPs (HRG Kd ∼2 nM) and competes with other plasma proteins for the NP surface, so forming a stable and quite homogeneous corona inhibiting nanoparticles binding to the macrophage membrane and their subsequent uptake. Conversely, in the case of lymphocytes and monocytes not only HRG but also several common plasma proteins can interchange in this inhibitory activity. The depletion of HRG and Kin-1 from HP or their plasma exhaustion by increasing NP concentration (>40 µg ml(-1) in 10% HP) lead to a heterogeneous hard corona, mostly formed by fibrinogen (Fibr), HDLs, LDLs, IgGs, Kallikrein and several minor components, allowing nanoparticle binding to macrophages. Consistently, the FCS-derived SiO2-NP hard corona, mainly formed by hemoglobin, α2 macroglobulin and HDLs but lacking HRG, permits nanoparticle uptake by macrophages. Moreover, purified HRG competes with FCS proteins for the NP surface, inhibiting their recruitment in the corona and blocking NP macrophage capture. HRG, the main component of the plasma-derived SiO2-NPs' hard corona, has antiopsonin characteristics and uniquely confers to these particles the ability to evade macrophage capture.


Subject(s)
Macrophages/metabolism , Nanoparticles/chemistry , Proteins/chemistry , Silicon Dioxide/chemistry , Animals , Blood Proteins/chemistry , Blood Proteins/metabolism , Cells, Cultured , Chromatography, High Pressure Liquid , Electrophoresis, Polyacrylamide Gel , Fluorescein-5-isothiocyanate/chemistry , Humans , Kininogens/chemistry , Kininogens/metabolism , Macrophages/cytology , Mice , Proteins/metabolism , Tandem Mass Spectrometry
19.
Biochim Biophys Acta ; 1848(1 Pt A): 134-44, 2015 Jan.
Article in English | MEDLINE | ID: mdl-25306964

ABSTRACT

Peptaibiotics, non-ribosomally synthetized peptides from various ascomycetes, are uniquely characterized by dialkylated a-amino acids, a rigid heli cal conformation, and membrane permeation properties. Although generally considered as antimicrobial peptides, peptaibiotics may display other toxicological properties, and their function is in many cases unknown. With the goal to define the biological activity and selectivity of the peptaibiotictrichogin GA IV from the human opportunist Trichodenna longibrachiatum we analyzed its membrane interaction,cytotoxic activity and antibacterial effect. Trichogin GA IV effectively killed several types of healthy and neoplastic human cells at doses (EC 50%= 4-6 ~) lacking antibiotic effects on both Gram- and Gram+ bacteria(MIC > 64 ~ ). The peptaibiotic distinctive (-terminal primary alcohol was found to cooperate with theN-terminal n-octanoyl group to permeate the membrane phospholipid bilayer and to mediate effective binding and active endocytosis of trichogin GA IV in eukaryotic cells, two steps essential for cell death induction.Replacement of one Gly with Lys plus the simultaneous esterification of the (-terminus, strongly increased trichogin GA IV anti-Gram+ activity (MIC 1-4 ~ ). but further mitigated its cytotoxicity on human cells.


Subject(s)
Cell Membrane/chemistry , Lipopeptides/chemistry , Membrane Lipids/chemistry , Unilamellar Liposomes/chemistry , Amino Acid Sequence , Anti-Bacterial Agents/chemistry , Anti-Bacterial Agents/metabolism , Anti-Bacterial Agents/pharmacology , Binding, Competitive , Cell Line , Cell Line, Tumor , Cell Membrane/drug effects , Cell Membrane/metabolism , Cell Membrane Permeability/drug effects , Cell Survival/drug effects , Cells, Cultured , Cholesterol/chemistry , Cholesterol/metabolism , Dose-Response Relationship, Drug , Endocytosis , HL-60 Cells , HeLa Cells , Hemolysis/drug effects , Humans , Lipopeptides/metabolism , Lipopeptides/pharmacology , Membrane Lipids/metabolism , Microbial Sensitivity Tests , Microscopy, Confocal , Phosphatidylcholines/chemistry , Phosphatidylcholines/metabolism , Phosphatidylethanolamines/chemistry , Phosphatidylethanolamines/metabolism , Phosphatidylglycerols/chemistry , Phosphatidylglycerols/metabolism , Unilamellar Liposomes/metabolism
20.
Nanomedicine (Lond) ; 9(16): 2481-97, 2014 Nov.
Article in English | MEDLINE | ID: mdl-24661258

ABSTRACT

AIM: We investigated monocyte and macrophage death and cytokine production induced by amorphous silica nanoparticles (SiO2-NPs) to clarify the role of defined serum corona proteins. MATERIALS & METHODS: The cytotoxic proinflammatory effects of SiO2-NPs on human monocytes and macrophages were characterized in no serum, in fetal calf serum and in the presence of purified corona proteins. RESULTS: In no serum and in fetal calf serum above approximately 75 µg/ml, SiO2-NPs lysed monocytes and macrophages by plasma membrane damage (necrosis). In fetal calf serum below approximately 75 µg/ml, SiO2-NPs triggered an endolysosomal acidification and caspase-1-dependent monocyte death (pyroptosis). The corona high-density lipoproteins:albumin ratio accounted for the features of the SiO2-NPs in serum. DISCUSSION: Corona high-density lipoproteins are a major determinant of the differential cytotoxic action of SiO2-NPs on monocytes and macrophages.


Subject(s)
Albumins/drug effects , Blood Proteins/drug effects , Lipoproteins, HDL/drug effects , Silicon Dioxide/pharmacology , Albumins/metabolism , Animals , Cattle , Cell Death , Humans , Lipoproteins, HDL/blood , Macrophages/drug effects , Monocytes/drug effects , Monocytes/metabolism , Nanoparticles/chemistry , Silicon Dioxide/chemistry
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