Imaging of compartmentalised intracellular nitric oxide, induced during bacterial phagocytosis, using a metalloprotein–gold nanoparticle conjugate

Abstract

Imaging of the in situ production of nitric oxide following phagocytosis of Escherichia coli bacteria using a NO nanobiosensor.

2-Amino-3′-dialkylaminobiphenyl-based fluorescent intracellular probes for nitric oxide surrogate N2O3

“…[6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25] In order to establish NO levels and activity, scientists have employed NO-specic electrodes [26][27][28][29][30][31][32][33][34] and chemical probes that, upon reaction with NO or its surrogates, produce a change in electron paramagnetic resonance (EPR), [35][36][37][38][39] UV-vis absorbance, 40,41 chemiluminescence, [42][43][44][45] and/or uorescence. [46][47][48][49][50][51][52][53][54][55]…”

Molecular nanogels as nanocarriers. Intracellular transport of photosensitizers and nitric oxide probes

“…Selected examples have been included in Table 4.2. 126 Controlled drug release, protection against enzymatic degradation Liposomes 119, 127 Enhanced photostability; in vitro: enhanced intracellular photodynamic efficacy, good intracellular uptake and increased cell death rate Chitosan (covalent bond) 128 In vitro (breast cancer): low dark toxicity, enhanced phototoxic effect Polyamidoamine (PAMAM) dendrimers (20 nm) 129 In vitro (Dalton's lymphoma ascites cells): decreased dark toxicity, enhanced photodynamic efficacy, efficient delivery of RB Silica nanoparticles 130 In vitro (oral and breast cancer cells): enhanced uptake, enhanced toxicity compared to free RB Gold nanoparticles (covalent bond) 131 In vitro (oral cancer cells): enhanced cellular uptake, enhanced PDT effect, enhanced therapeutic effects Mesostructured silica nanoparticles (150-180 nm) (covalent bond) 132,133 Enhanced singlet oxygen generation, in vitro (melanoma cells) phototoxicity Semiconductor zinc oxide NPs (24 nm) 134 Increased ROS generation, in vitro (HeLa cells) toxicity Fe3O4@Au@mSiO2 nanoplatform (60 nm) (covalent bond) 135 Enhanced singlet oxygen generation Cationic phosphorous dendrimer 136 Enhanced singlet oxygen generation, in vitro (basal carcinoma cells): enhanced phototoxic effect, increased cellular uptake, enhanced PDT activity Light-triggered liposomes containing gold nanoparticles 137 In vitro: good cell-killing efficacy of RB combined with gold Bis(pyrene)@RB-Hemoglobin nanocomplex (150 nm) 138 In vitro, in vivo: increased treatment depth, avoiding of tumour hypoxia, improved PDT efficiency NaGdF4:Yb 3+ /Er 3+ UCNPs (covalent bond) 139 In vitro (lung cancer cells) phototoxicity Barium titanate and RB composite nanoparticles (BT@PAH/RB/PAH) 140 Enhanced singlet oxygen generation, in vitro (cervical cancer cells): increased PDT effect Carboxymethyl chitosan 141 In vitro (oral cancer cells): enhanced PDT efficacy…”

“…132,133 The external stimulation of RAW 264.7 cells to produce NO requires interferon-γ (INF-γ) and lipopolysaccharide (LPS), which activate the inducible nitric oxide synthase (iNOS). 134,135 The cytotoxicity of the nanoparticles was tested before these studies to work in harmless conditions although is described later in the text (Section 5.3.3.5).…”

“…UV polymerization is the most common approach for the preparation of lipogels that followed that initial work. The polymeric hydrogel@liposome particles prepared in this way include, for example, poly(N-isopropylacrylamide), [127][128][129][130] cross-linked polymers derived from dextran, 131,132 polyethylene glycol, [133][134][135] polyacrylic acid, 122,136 polyglycidol 137 and ethyl methacrylate derivatives 123 and hyaluronic acid. 138 Other strategies include thermally initiated polymerization, which has been used to form a redox-responsive nanogel 124 and a polymethacrylate derivative inside liposomes.…”

“…This effect diminishes the energy gap in the absorption spectra leading to λmax red-shifts. 120,152 Indeed, the same bathochromic effect is produced when RB changes its environment going from water to solvents with reduced polarity as can be seen in Table 4. 127 22 -RB and lipoprotein complex 121 -5 RB adsorbed to Aβ42 110 12 -RB adsorption to collagen-like peptide 123 20 -RB adsorbed to PAMAM dendrimers 151 11 11 RB adsorbed on microgranular cellulose 154 12 -RB aggregated in alumina-coated silica nanoparticles 155 16 -RB adsorbed on PDDA polymer 156 10 (solution), 23 (film) 10 (solution), 23 (film) RB dimer/aggregates adsorbed in PAH-RB films 157 21 -RB covalent linked to mesostructured silica nanoparticles 132 17 25 RB bound to ZnO nanoparticles 134 5 - Finally, is also worthy discussing if RB is aggregated or not in our systems, as the formation of aggregates when RB is encapsulated has been often discussed in the literature. 154,155 RB tends to aggregate in solution, driven by hydrophobic effects, and does not follow Beer's law at concentrations above 5x10 -5 M. [158][159][160][161] When RB dimers are formed, a change in the ratio of the peak (ca.…”