Nanoparticles consisting of metal-organic frameworks (NMOFs) modified with nucleic acid binding strands are synthesized. The NMOFs are loaded with a fluorescent agent or with the anticancer drug doxorubicin, and the loaded NMOFs are capped by hybridization with a complementary nucleic acid that includes the ATP-aptamer or the ATP-AS1411 hybrid aptamer in caged configurations. The NMOFs are unlocked in the presence of ATP via the formation of ATP-aptamer complexes, resulting in the release of the loads. As ATP is overexpressed in cancer cells, and since the AS1411 aptamer recognizes the nucleolin receptor sites on the cancer cell membrane, the doxorubicin-loaded NMOFs provide functional carriers for targeting and treatment of cancer cells. Preliminary cell experiments reveal impressive selective permeation of the NMOFs into MDA-MB-231 breast cancer cells as compared to MCF-10A normal epithelial breast cells. High cytotoxic efficacy and targeted drug release are observed with the ATP-AS1411-functionalized doxorubicin-loaded NMOFs. The ORCID identification number(s) for the author(s) of this article can be found under https://doi.org/10.1002/adfm.201702102.conductivity material for fuel cells, [16][17][18] and as a composite material for sensing applications. [4,[19][20][21] Substantial recent efforts are directed toward the development of stimulitriggered reconfigurable nucleic acid structures (DNA switches and DNA machines). [22][23][24][25][26][27] Porous inorganic materials, e.g., SiO 2 nanoparticles, [28] microcapsules, [29] or organic hydrogels, [30][31][32] were loaded with substrates (or drugs) and caged with stimuli-responsive nucleic acid locks. In the presence of appropriate triggers, the stimuli-responsive loaded matrices were unlocked, resulting in the release of the loads. Different stimuli such as pH, [33] light, [34] heat, [35] catalytic nucleic acids, [36] or aptamer-ligand complexes [37] were used to unlock the substrate-loaded materials. Naturally, the capping of the highly porous substrate-loaded MOFs with stimuli-responsive DNAs could yield efficient DNA/ MOFs hybrids as drug delivery systems. Despite the chemical modification of MOFs with stimuli-responsive chemical capping units, [38][39][40][41][42][43] the integration of nucleic acids with MOFs is scarce and involved only the carrying of DNA. [44][45][46][47] Recently, we reported [48] on the successful entrapment of substrates in macrocrystalline MOFs protected by pH-responsive or K + -stabilized G-quadruplex capping units and the triggered unlocking of the MOFs, and the release of loads, by altering the pH, or their treatment with 18-crown-6 ether. While this study demonstrated the successful synthesis of stimuli-responsive DNAgated, substrate-loaded, microcrystalline MOFs, these materials suffer from a basic limitation because they are nonpermeable into cells. That is, their potential application as stimuli-responsive drug carriers is limited. The synthesis of nanometersized MOF particles is well established, [49][50][51][52][53][54] but ...

Metal-organic frameworks (MOFs) represent a broad class of porous materials composed of metal ions cross-linked by organic ligands. [1] Besides the interesting structural features of MOFs, [2] many different applications of MOFs were reported [3] including their use as drug carriers, [4] catalysts, [5] sensors, [6] gas storage, [7] separation, [8] optical devices, [9] photocatalysts, [10] and as micromotors. [11] The use of the highly porous MOFs as structural scaffolds for the development of catalysts is particularly interesting. [12] Different methods to synthesize MOF-based catalysts were developed and these included the incorporation of catalytic complexes into the pores of the MOFs, [13] the incorporation of metal complexes as functional ligands of the MOF frameworks, [14] and the construction of MOFs that include ligands for the postsynthetic anchoring of metal ions and the www.advancedsciencenews.com www.small-journal.com small NANO MICRO

Nanoparticles composed of Prussian Blue, PB, and the cyanometalate structural analogues, CuFe, FeCoFe, and FeCo, are examined as inorganic clusters that mimic the functions of peroxidases. PB acts as a superior catalyst for the oxidation of dopamine to aminochrome by HO. The oxidation of dopamine by HO in the presence of PB is 6-fold faster than in the presence of CuFe. The cluster FeCo does not catalyze the oxidation of dopamine to aminochrome. The most efficient catalyst for the generation of chemiluminescence by the oxidation of luminol by HO is, however, FeCo, and PB lacks any catalytic activity toward the generation of chemiluminescence. The order of catalyzed chemiluminescence generation is FeCo ≫ CuFe > FeCoFe. The clusters PB, CuFe, FeCoFe, and FeCo mimic the functions of NADH peroxidase. The catalyzed oxidation of NADH by HO to form NAD follows the order PB ≫ CuFe ∼ FeCoFe, FeCo. The efficient generation of chemiluminescence by the FeCo-catalyzed oxidation of luminol by HO is used to develop a glucose sensor. The aerobic oxidation of glucose in the presence of glucose oxidase, GOx, yields gluconic acid and HO. The chemiluminescence intensities formed by the GOx-generated HO relate to the concentration of glucose, thus providing a quantitative readout signal for the concentrations of glucose.

The present study investigated dual carbon-bromine isotope fractionation of the common groundwater contaminant ethylene dibromide (EDB) during chemical and biological transformations, including aerobic and anaerobic biodegradation, alkaline hydrolysis, Fenton-like degradation, debromination by Zn(0) and reduced corrinoids. Significantly different correlation of carbon and bromine isotope fractionation (ΛC/Br) was observed not only for the processes following different transformation pathways, but also for abiotic and biotic processes with, the presumed, same formal chemical degradation mechanism. The studied processes resulted in a wide range of ΛC/Br values: ΛC/Br = 30.1 was observed for hydrolysis of EDB in alkaline solution; ΛC/Br between 4.2 and 5.3 were determined for dibromoelimination pathway with reduced corrinoids and Zn(0) particles; EDB biodegradation by Ancylobacter aquaticus and Sulfurospirillum multivorans resulted in ΛC/Br = 10.7 and 2.4, respectively; Fenton-like degradation resulted in carbon isotope fractionation only, leading to ΛC/Br ∞. Calculated carbon apparent kinetic isotope effects ((13)C-AKIE) fell with 1.005 to 1.035 within expected ranges according to the theoretical KIE, however, biotic transformations resulted in weaker carbon isotope effects than respective abiotic transformations. Relatively large bromine isotope effects with (81)Br-AKIE of 1.0012-1.002 and 1.0021-1.004 were observed for nucleophilic substitution and dibromoelimination, respectively, and reveal so far underestimated strong bromine isotope effects.

Protein folding is crucial for biological activity. Proteins’ failure to fold correctly underlies various pathological processes, including amyloidosis, the aggregation of insoluble proteins (e.g., lysozymes) in organs. The exact conditions that trigger the structural transition of amyloids into β-sheet-rich aggregates are poorly understood, as is the case for the amyloidogenic self-assembly pathway. Ultrasound is routinely used to destabilize a protein’s structure and enhance amyloid growth. Here, we report on an unexpected ultrasound effect on lysozyme amyloid species at different stages of aggregation: ultrasound-induced structural perturbation gives rise to nonamyloidogenic folds. Our infrared and X-ray analyses of the chemical, mechanical, and thermal effects of sound on lysozyme’s structure found, in addition to the expected ultrasound-induced damage, evidence of irreversible disruption of the β-sheet fold of fibrillar lysozyme resulting in their structural transformation into monomers with no β-sheets. This structural transition is reflected in changes in the kinetics of protein self-assembly, namely, either prolonged nucleation or accelerated fibril growth. Using solution X-ray scattering, we determined the structure, the mass fraction of lysozyme monomer, and the morphology of its filamentous assemblies formed under different sound parameters. A nanomechanical analysis of ultrasound-modified protein assemblies revealed a correlation between the β-sheet content and elastic modulus of the protein material. Suppressing one of the ultrasound-derived effects allowed us to control the structural transformations of lysozyme. Overall, our comprehensive investigation establishes the boundary conditions under which ultrasound damages protein structure and fold. This knowledge can be utilized to impose medically desirable structural modifications on amyloid β-sheet-rich proteins.