Nanoscale Complex Research Articles

Inhibition of post-trabeculectomy fibrosis via topically instilled antisense oligonucleotide complexes co-loaded with fluorouracil

Trabeculectomy is the mainstay of surgical glaucoma treatment, while the success rate was unsatisfying due to postoperative scarring of the filtering blebs. Clinical countermeasures for scar prevention are intraoperative intervention or repeated subconjunctival injections. Herein, we designed a co-delivery system capable of transporting fluorouracil and anti-TGF-β2 oligonucleotide to synergistically inhibit fibroblast proliferation via topical instillation. This co-delivery system was built based on a cationic dendrimer core (PAMAM), which encapsulated fluorouracil within hydrophobic cavity and condensed oligonucleotide with surface amino groups, and was further modified with hyaluronic acid and cell-penetrating peptide penetratin. The co-delivery system was self-assembled into nanoscale complexes with increased cellular uptake and enabled efficient inhibition on proliferation of fibroblast cells. In vivo studies on rabbit trabeculectomy models further confirmed the anti-fibrosis efficiency of the complexes, which prolonged survival time of filtering blebs and maintained their height and extent during wound healing process, exhibiting an equivalent effect on scar prevention compared to intraoperative infiltration with fluorouracil. Qualitative observation by immunohistochemistry staining and quantitative analysis by Western blotting both suggested that TGF-β2 expression was inhibited by the co-delivery complexes. Our study provided a potential approach promising to guarantee success rate of trabeculectomy and prolong survival time of filtering blebs.

Simultaneous Two-Angle Axial Ratiometry for Fast Live and Long-Term Three-Dimensional Super-Resolution Fluorescence Imaging.

The application of optical microscopy in four-dimensional (spatial and temporal) super-resolution imaging poses challenges because of the requirement of a long acquisition time or high illumination intensity. In this paper, we introduce simultaneous two-angle axial ratiometry (STARII) for <20 nm axial super-resolution imaging and for fast and long-term imaging of live cells up to hundreds of frames per second. This method involves recording two raw images in two incident angle channels in the context of evanescent wave illumination and obtaining the corresponding intensity ratio. Furthermore, we demonstrate the combination of STARII with the lateral super-resolution method to resolve three-dimensional nanoscale structures of microtubules and to visualize the long-term dynamical plasma membrane curvature and fast remodeling of endoplasmic reticulum tubule meshwork and three-way junctions. These demonstrations indicate an important potential application of STARII in investigating nanoscale cellular complex processes in the native state.

Heteroprotein complex of soy protein isolate and lysozyme: Formation mechanism and thermodynamic characterization

The electrostatic assembly between heteroproteins is one of the most important applications of associative interaction. The present study investigated the effects of pH and NaCl on the formation rules, phase behavior, and thermodynamic changes of soy protein isolate (SPI)/lysozyme (LYS) complexes. The hydrodynamic diameter of SPI significantly increased as pH was lowered to 6.5, whereas that of LYS significantly increased at pH ≥ 7.5, as a result of self-aggregation. Electrostatic assembly between SPI and LYS completely complies with the charge compensation, producing nanoscale (about 200 nm) and microscale (about 5 μm) complexes at different mixing ratio. However, NaCl can lower ζ-potential of SPI and LYS, and weaken the electrostatic interaction between heteroproteins. The presence of 200 mM NaCl can completely inhibit the electrostatic assembly between SPI and LYS (1 mg/mL). Not only electrostatic interactions but also hydrogen bonds participated in the complex. As the observation of phase-contrast mode, the pH, stoichiometry, NaCl, and assembling time significantly affected size and shape of SPI/LYS complexes, whereas all SPI/LYS complexes exhibited solid-liquid phase separation on the time scale of 0–60 min. Isothermal titration calorimetry analysis indicated that SPI/LYS complex was thermodynamically favored (ΔG < 0), both the exotherm (ΔH < 0) and the entropy gain contributed to SPI/LYS assembling while the entropy gain might be the dominant term. Moreover, the absolute values of ΔG, ΔH, and ΔS significantly decreased with increasing NaCl concentration.

Formation of Structurally Ordered Nanoscale Complexes of DNA with Nuclear Proteins HMGB1 and H1

The structural organization of DNA in complex with linker histone H1 and non-histone chromosomal protein HMGB1 have been studied using atomic force microscopy and vibrational spectroscopy. The possibility of formation ordered nanoscale DNA-protein complexes is reported.

Isolation and subunit structure of the xylanosome complex produced by Actinotalea fermentans JCM9966.

Xylanosomes, also known as hemicellulosomes, are hemicellulose-degrading nano-scale multienzyme complexes produced by some Firmicutes, Actinobacteria, and Fungi. Here we report the isolation of the MECs produced by Actinotalea fermentas JCM9966, as well as the functional studies and subunit structure revealed by proteomic identifications. The isolated MECs here shows similar particle size with the xylanosomes produced by C. cellulans F16, have several conserved multi-domain proteins, while differ significantly in enzymatic activities and low molecular weight subunit compositions, indicating diverse capability as well as bias in degrading hemicelluloses.

Molecular dynamics simulation of Y-type nanomotors with different angles in aqueous solution

Nanomotors are of great importance when studying nanoelectromechanical systems that contain carbon nanotube (CNT) based nanomotors for controlled motion in water using a rotating electric field. In this paper, Y-type nanomotor structures based on CNTs immersed in an aqueous solution are designed, and systems with different Y-type structure angles are simulated using molecular dynamics. The simulation results suggest that when the rotating electric field speed is appropriate, changing the Y-type structure angle can adjust the hysteresis (forward and backward motion) of nanomotor rotors during rotation. Precise control over the rotation angle of the nanomotor rotor improves its working efficiency. The enclosed simulation results are an important reference when designing nanoscale propellers and complex structured nanogear systems in aqueous solutions.

Intracellular Delivery of Glucose Oxidase for Enhanced Cytotoxicity toward PSMA-Expressing Prostate Cancer Cells.

Reactive oxygen species (ROS) forming enzymes are of significant interest as anticancer agents due to their potent cytotoxicity. A key challenge in their clinical translation is attaining site-specific delivery and minimizing biodistribution to healthy tissues. Here, complexes composed of the ROS enzyme glucose oxidase (GOX), poly-l-lysine-grafted-polyethylene glycol (PLL-g-PEG), and anti-prostate specific membrane antigen (anti-PSMA) monoclonal antibody are synthesized for localized delivery and uptake in prostate cancer cells. Formation of anti-PSMA-PLL-g-PEG/GOX results in nanoscale complexes ≈30 nm in diameter with a ζ-potential of 6 mV. The anti-PSMA-PLL-g-PEG/GOX complexes show significant cytotoxicity (≈60% reduction in cell viability) against PSMA-expressing LNCaP cells compared to unmodified GOX. Importantly, cytotoxicity in LNCaP cells occurrs concurrently with anti-PSMA-PLL-g-PEG/GOX uptake and increases in intracellular generation of ROS. These results demonstrate that cytotoxicity of ROS inducing enzymes can be enhanced by intracellular delivery compared to equivalent concentrations of free enzyme, providing a novel means for cancer therapy.

Inclusion Complexes of Melphalan with Gemini-Conjugated β-Cyclodextrin: Physicochemical Properties and Chemotherapeutic Efficacy in In-Vitro Tumor Models.

β-cyclodextrin (βCD) has been widely explored as an excipient for pharmaceuticals and nutraceuticals as it forms stable host–guest inclusion complexes and enhances the solubility of poorly soluble active agents. To enhance intracellular drug delivery, βCD was chemically conjugated to an 18-carbon chain cationic gemini surfactant which undergoes self-assembly to form nanoscale complexes. The novel gemini surfactant-modified βCD carrier host (hereafter referred to as 18:1βCDg) was designed to combine the solubilization and encapsulation capacity of the βCD macrocycle and the cell-penetrating ability of the gemini surfactant conjugate. Melphalan (Mel), a chemotherapeutic agent for melanoma, was selected as a model for a poorly soluble drug. Characterization of the 18:1βCDg-Mel host–guest complex was carried out using 1D/2D 1H NMR spectroscopy and dynamic light scattering (DLS). The 1D/2D NMR spectral results indicated the formation of stable and well-defined 18:1βCDg-Mel inclusion complexes at the 2:1 host–guest mole ratio; whereas, host–drug interaction was attenuated at greater 18:1βCDg mole ratio due to hydrophobic aggregation that accounts for the reduced Mel solubility. The in vitro evaluations were performed using monolayer, 3D spheroid, and Mel-resistant melanoma cell lines. The 18:1βCDg-Mel complex showed significant enhancement in the chemotherapeutic efficacy of Mel with 2–3-fold decrease in Mel half maximal inhibitory concentration (IC50) values. The findings demonstrate the potential applicability of the 18:1βCDg delivery system as a safe and efficient carrier for a poorly soluble chemotherapeutic in melanoma therapy.

Preparation of a nanoscale dihydromyricetin-phospholipid complex to improve the bioavailability: in vitro and in vivo evaluations

Dihydromyricetin (DMY), a flavanonol compound found as the most abundant and bioactive constituent in Ampelopsis grossedentata (Hand-Mazz) W.T. Wang, possesses numerous pharmacological activities, such as antioxidant, anti-inflammation, anticancer, anti-microbial, hypoglycemic and hypolipidemic effects, and so on. Recently, DMY shows a promising potential to develop as an agent for the prevention and treatment of Type 2 diabetes mellitus (T2DM). However, the low oral bioavailability of DMY was one of the special concerns to be resolved for its clinical applications. In this study, DMY phospholipid complex (DMY-HSPC COM) was prepared by the solvent evaporation technique and optimized with DMY combination ratio. Scanning electron microscopy (SEM), X-ray powder diffraction (XRPD), differential scanning calorimetry (DSC), and Fourier transform infrared spectrophotometry (FT-IR) were carried to characterize the formation of DMY-HSPC COM. The particle size, zeta potential, drug loading and solubility of DMY-HSPC COM were further investigated. The phospholipid complex technology could significantly improve the solubility of DMY. Pharmacokinetic study results of DMY-HSPC COM in healthy SD rats and T2DM rats demonstrated that the oral bioavailability was significantly increased when compared with pure DMY as well, which could be attributed to the improvement of the aqueous solubility of the complex, absorption promotion and a probable decrease in intestinal and hepatic metabolism. In addition, when compared with healthy SD rats, pharmacokinetic parameters of pure DMY and DMY-HSPC COM showed significant difference in T2DM rats. Thus, phospholipid complex technology holds a promising potential for increasing the oral bioavailability of DMY.

Catechin solubilization by spontaneous hydrogen bonding with poly(ethylene glycol) for dry eye therapeutics

Catechin exhibits various pharmacological effects, yet its poor aqueous solubility limits its clinical use. Here, we investigate a facile catechin solubilization method via spontaneous hydrogen bonding between catechin and poly(ethylene glycol) (PEG). The method is extremely simple in that mixing PEG with catechin followed by lyophilization completely converts insoluble catechin to soluble PEG/catechin nanoscale complexes. This solubilized catechin formulation is useful for preparing eyedrop medicine, and we demonstrate that the solubilized catechin exhibits therapeutic effect upon dry eye diseases.

WATER-SOLUBLE POLYMERIC IONIC 5-FLUOROURACIL COMPLEX BASED ON METHACRYLIC ACID COPOLYMERS

Objective: The objective of this work was to obtain a water-soluble 5-fluorouracil (5-FU) polymeric complex on the basis of a methacrylic acid (MAA) copolymer to be used as an injectable chemotherapeutic agent.&#x0D; Methods: A polymeric carrier was synthesized using tert-butyl methacrylate (TBMA) as a monomer, thioglycolic acid, and azobisisobutyronitrile as a radical polymerization initiator. The polymer was converted by acid hydrolysis into a water-soluble copolymer of TBMA and MAA of 20: 80 mass%, respectively. The copolymer of TBMA and MAA was modified with 5-FU. Their formation was proved using IR and UV spectroscopy. The particle size of the 5-FU polymeric complex was estimated by turbidimetry, which is based on measuring the intensity of light transmitted through a disperse system. The release of 5-FU from the obtained ionic complexes by dialysis in vitro was evaluated.&#x0D; Results: Polymeric carriers were obtained with different amounts of 5-FU (5, 15, 25, 50 mol%). A high peak at λ = 266 nm was observed in the UV spectrum of the polymeric carrier (characteristic of 5-FU). The particle size was estimated at 13 nm for the complex with 5 mol% 5-FU and 26.8 n for the complex with 50 mol% 5-FU. The 5-FU release was estimated in two parallel experiments at 37 °C. One utilized a phosphate-citrate buffer with pH 5.0 to model the intracellular space and the other, a phosphate buffer with pH 7.4 to model the intravascular space. Two systems, with 5 and 15 mol% 5-FU, were chosen for testing. In both phosphate buffer and phosphate-citrate buffer, 5-FU was released from the polymeric complex with 5 mol% 5-FU approximately 1.3 times faster than from the complex containing 5 mol% 5-fluorouracil. The kinetics of 5-FU release from the polymeric complex (5 mol% 5-fluorouracil) showed that the 5-FU release was 77.9% in phosphate-citrate buffer and 59.6% in phosphate buffer over 52 h of dialysis. When the 5-FU release kinetics was studied with the polymeric complex containing 15 mol% 5-FU, the 5-FU release was 100.0% in phosphate-citrate buffer and 75.1% in phosphate buffer over 57 h of dialysis.&#x0D; Conclusion: Water-soluble nanoscale complexes of 5-FU with TBMA–MAA copolymers extend application of 5-FU, while its general toxicity might be lower. The complexes are sufficiently stable at pH 7.4 and readily release 5-FU at pH 5.0.

Cation sensing by luminescent high-nuclearity Zn-Eu Schiff base nanoscale complexes: high sensitivity to Ag+ and Cd2+ ions at the ppm level.

Three polynuclear Zn-Ln nanoscale complexes [Ln2Zn2(L1)2(OAc)6] (Ln = Eu (1) and Nd (2)) and [Eu6Zn6(L2)2(L3)2O2(OAc)18] (3) were constructed using two Schiff base ligands featuring Ph(CH2)Ph (H2L1) and naphthyl (H2L2) backbones. The use of the Schiff base ligand H2L1 leads to the formation of linear complexes 1 and 2 with molecular sizes of approximately 7 × 10 × 24 Å, while planar complex 3 (approximately 10 × 15 × 22 Å) is constructed from H2L2. In 1-3, the chromogenic Zn/ligand moieties can absorb energy from and transfer energy to lanthanide centers, and all of these complexes display the typical emissions of Ln3+ ions. Interestingly, 3 displays luminescence response to the addition of metal ions and has high sensitivity to Ag+ and Cd2+ ions at the ppm level.

ROS-Sensitive Cross-Linked Polyethylenimine for Red-Light-Activated siRNA Therapy.

The extremely inefficient endosomal escape and intracellular release are the central barriers for effective nanocarrier-mediated RNA interference (RNAi) therapeutics. Accelerating endosomal escape and triggering intracellular release with red or near-infrared light are of particular interest due to its spatiotemporal controllability, great tissue penetration, and minimal phototoxicity. As a proof-of-concept, we explored an innovative siRNA delivery system, TKPEI-Ce6, that is prepared by the linking reaction of branched polyethylenimine, a reactive oxygen species (ROS)-labile crosslinker, poly(ethylene glycol), and chlorin e6 (Ce6). TKPEI-Ce6 efficiently condensed siRNA to form the nanoscale complex TKPEI-Ce6/siRNA. Under red-light irradiation (660 nm), the conjugated Ce6 produced ROS, which could accelerate endosomal escape by the destruction of the endosomal membranes and then trigger the cytosolic release of siRNA by cleaving the thioketal linker and further disrupting the nanostructure of the TKPEI-Ce6/siRNA. Therefore, the superior silencing efficiency of siRNA was collectively realized toward an anticancer therapy. This concept also provides new avenues for light-controlled site-specific downregulation of targeted gene expression in vivo, facilitating precise treatment of numerous diseases.

First-Principles and Thermodynamics Study of Compositionally Tuned Complex Metal Oxides: Cation Release from the (001) Surface of Mn-Rich Lithium Nickel Manganese Cobalt Oxide.

Compositional tuning of nanoscale complex metal oxides (CMOs) can lead to enhanced performance and favorable properties for a variety of energy-related applications. However, investigations of the nanoscale CMOs used in energy storage technologies demonstrate that these nanomaterials may have an adverse biological impact, highlighting a fundamental knowledge gap between nanomaterial design and the structure and properties at the end of life. CMO nanomaterials can enter the environment due to improper disposal, where they undergo subsequent (as of yet poorly understood) nanoscale transformations that may affect biological response and, ultimately, environmental fate. This points to the need for studies at the nano-bio interface that can be used to shape rules for the redesign of CMOs: materials that are are potentially more benign by design and serve as examples of sustainable nanotechnology. The example given here is to enrich lithium nickel manganese cobalt oxide, Li x(Ni yMn zCo1- y- z)O2 (NMC), with Mn to create a family of materials that are less expensive and potentially less toxic to a wide range of organisms. In this paper, we investigate the structure and electronic states of Mn-rich NMC at the density functional theory (DFT) level to elucidate the interplay of redox properties, oxidation state, and coordination environment of a compositionally tuned CMO. We find that the oxidation states of Ni and Co remain mostly unaffected while Mn exists as both Mn2+ and Mn4+. Our models show that the ratio of Mn2+ and Mn4+ varies with changes in the coordination environment, such as the identity of neighboring atoms and surface OH group coverage. The surface metal release properties of Mn-rich NMC compositions are predicted using a DFT + solvent ion model and show that Mn-rich NMC compositions are inherently more prone to dissolution than NMC and that this is attributed to the changes in oxidation state of the transition metals in Mn-rich NMC.

Multi experimental and computational studies for DNA and HSA interaction of new nano-scale ultrasound-assisted synthesized Pd(II) complex as a potent anticancer drug

As for daily increasing mortality rate in world due to the growth of cancer causing agents, design and synthesis of new compounds with anticancer potential benefits is one of the most important challenges for researchers. In the present work, we synthesized a new Schiff base Pd(II) complex in bulk-scale and also in nano-scales by Sonochemical method. The structure of synthesized complex was determined by single crystal X-ray diffraction technique. Then the cell viability percent of HeLa cancer cells was studied by MTT assay. The results confirmed that reducing the size has salient effect in annihilation of cancer cells. Also, nano-scale complex reached to IC50 in 10 μM of concentration. Binding ability of the nano- and bulk-scale Pd(II) Schiff base complex with calf thymus DNA and human serum albumin was investigated using combination of experimental (fluorescence, circular dichroism (CD) and viscosity) and computational (molecular docking, molecular dynamics simulation and QM/MM) methods. The estimated binding constants for the complex in both of bulk- and nano-scales showed that the nano-scale complex binds more tightly to DNA than its bulk-scale form. This finding is in good agreement with MTT assay results. Molecular docking studies revealed that Pd(II) complex binds to the minor groove and IB binding site of DNA and HSA, respectively. Also, MD simulation studies showed that complexation with the Pd(II) complex changes the structure of HSA with compared to free protein. Finally, the ONIOM results indicated that the structural parameters of the compound changed along with binding to DNA and HSA, indicating the strong interaction between the compound and these biomacromolecules. The values of binding constants depend on the extent of the resultant changes.

Nanoscale polyelectrolyte complexes encapsulating mRNA and long-chained siRNA for combinatorial cancer gene therapy

To precisely regulate target genes that are abnormally expressed in cancers, we suggest an RNA-mediated multigene targeting system that co-encapsulates siRNA against vascular endothelial growth factor (VEGF) and mRNA encoding phosphatase and tensin homolog (PTEN). Polymerized long-chain siRNAs (L-siRNAs) formed stable and condensed nanocomplexes with mRNAs using thiolated glycol chitosans (tGCs) as gene carriers. The mRNA/L-siRNA/tGC nanocomplexes (MSNs) exhibited efficient intracellular delivery and superior anti-tumor efficiency with simultaneous up and down-regulation of PTEN and VEGF, respectively. The MSN system can be considered as a new platform for cancer gene therapy requiring accurate control of multiple gene expressions.

RNA-Peptide nanoplexes drug DNA damage pathways in high-grade serous ovarian tumors.

DNA damaging chemotherapy is a cornerstone of current front‐line treatments for advanced ovarian cancer (OC). Despite the fact that a majority of these patients initially respond to therapy, most will relapse with chemo‐resistant disease; therefore, adjuvant treatments that synergize with DNA‐damaging chemotherapy could improve treatment outcomes and survival in patients with this deadly disease. Here, we report the development of a nanoscale peptide‐nucleic acid complex that facilitates tumor‐specific RNA interference therapy to chemosensitize advanced ovarian tumors to frontline platinum/taxane therapy. We found that the nanoplex‐mediated silencing of the protein kinase, MK2, profoundly sensitized mouse models of high‐grade serous OC to cytotoxic chemotherapy by blocking p38/MK2‐dependent cell cycle checkpoint maintenance. Combined RNAi therapy improved overall survival by 37% compared with platinum/taxane chemotherapy alone and decreased metastatic spread to the lungs without observable toxic side effects. These findings suggest (a) that peptide nanoplexes can serve as safe and effective delivery vectors for siRNA and (b) that combined inhibition of MK2 could improve treatment outcomes in patients currently receiving frontline chemotherapy for advanced OC.

Nanoformulation of Brain-Derived Neurotrophic Factor with Target Receptor-Triggered-Release in the Central Nervous System.

Brain-derived neurotrophic factor (BDNF) is identified as a potent neuroprotective and neuroregenerative agent for many neurological diseases. Regrettably, its delivery to the brain is hampered by poor serum stability and rapid brain clearance. Here, a novel nanoformulation is reported composed of a bio-compatible polymer, poly(ethylene glycol)-b-poly(L-glutamic acid) (PEG-PLE), that hosts the BDNF molecule in a nanoscale complex, termed here Nano-BDNF. Upon simple mixture, Nano-BDNF spontaneously forms uniform spherical particles with a core-shell structure. Molecular dynamics simulations suggest that binding between BDNF and PEG-PLE is mediated through electrostatic coupling as well as transient hydrogen bonding. The formation of Nano-BDNF complex stabilizes BDNF and protects it from nonspecific binding with common proteins in the body fluid, while allowing it to associate with its receptors. Following intranasal administration, the nanoformulation improves BDNF delivery throughout the brain and displays a more preferable regional distribution pattern than the native protein. Furthermore, intranasally delivered Nano-BDNF results in superior neuroprotective effects in the mouse brain with lipopolysaccharides-induced inflammation, indicating promise for further evaluation of this agent for the therapy of neurologic diseases.

Main sources оf uncertainties in measuring weak near-infrared water vapor continuum absorption with a Fourier spectrometer with a long optical path

We examine the main sources of uncertainties when measuring the near-infrared water vapor continuum absorption with the Fourier spectrometer complex of the Institute of Atmospheric Optics, Siberian Branch, Russian Academy of Sciences. The instrumental and methodical errors are considered, including errors in determination of the baseline, as well as possible impact of nanoscale complexes of water molecules.

Synthesis and Photostability of 2-(4-isobutoxyphenyl)-6-Hydrazino-1,8-Naphthalimide as Fluorescence Dye and Its Selenium Nanoscale Complex Doped in Polymethyl Methacrylate Polymeric Sheet Exposed to UV-Vis Radiation

Synthesis and Photostability of 2-(4-isobutoxyphenyl)-6-Hydrazino-1,8-Naphthalimide as Fluorescence Dye and Its Selenium Nanoscale Complex Doped in Polymethyl Methacrylate Polymeric Sheet Exposed to UV-Vis Radiation