Radiolabeled multi-layered coated gold nanoparticles as potential biocompatible PET/SPECT tracers

The demand for tailored, disease-adapted, and easily accessible radiopharmaceuticals is one of the most persistent challenges in nuclear imaging precision medicine. The aim of this work was to develop two multimodal radiotracers applicable for both SPECT and PET techniques, which consist of a gold nanoparticle core, a shell involved in radioisotope entrapment, peripherally placed targeting molecules, and biocompatibilizing polymeric sequences. Shell decoration with glucosamine units located in sterically hindered molecular environments is expected to result in nanoparticle accumulation in high-glucose-consuming areas. Gold cores were synthesized using the Turkevich method, followed by citrate substitution with linear PEG α,ω-functionalized with thiol and amine groups. The free amine groups facilitated the binding of branched polyethyleneimine through an epoxy ring-opening reaction by using PEG α,ω-diglycidyl ether as a linker. Afterwards, the glucose-PEG-epoxy prepolymer has been grafted onto the surface of AuPEG-PEI conjugates. Finally, the AuPEG-PEI-GA conjugates were radiolabeled with 99mTc or 68Ga. Instant thin-layer chromatography was used to evaluate the radiolabeling yield. The biocompatibility of non-labeled and 99mTc or 68Ga labeled nanoparticles was assessed on normal fibroblasts. The 99mTc complexes remained stable for over 22 hours, while the 68Ga containing ones revealed a slight decrease in stability after 1 hour.

Photoluminescence of Argan-Waste-Derived Carbon Nanodots Embedded in Polymer Matrices

In this work, photoluminescent (PL) carbon nano dots (CNDs) prepared from argan waste were embedded in highly optical transparent poly(styrene-co-acrylonitrile) (PSA) and cyclo-olefin copolymer (COC) matrices, which were further processed into thin films. In the first step, the luminescent CNDs were prepared through thermal processing of fine-groundargan waste, followed, in the second step, by direct dispersion in the polymer solutions, obtained by solving PSA and COC in selected solvents. These two polymer matrices were selected due to their high optical transparency, resilience to various environmental factors, and ability to be processed as quality thin films. The structural configuration of the CNDs was investigated through EDX, XPS, and FTIR, while DLS, HR-SEM, and STEM were used for their morphology investigation. The luminescence of the prepared CNDs and resulted polymer nanocomposites was thoroughly investigated through steady-state, absolute PLQY, and lifetime fluorescence. The quality of the resulted CND-polymer nanocomposite thin films was evaluated through AFM. The prepared highly luminescent thin films with a PL conversion efficiency of 30% are intended to be applied as outer photonic conversion layers on solar PV cells for increasing their conversion efficiency through valorization of the UV component of the solar radiation.

Electrochemical Sensor for Tryptophan Determination Based on Trimetallic-CuZnCo-Nanoparticle-Modified Electrodes

The superior properties of electrodeposited trimetallic CuZnCo nanoparticles, arising from the synergistic effect of combining the unique features of metallic components, were confirmed using voltametric measurements. The surface morphology and structure of the as-prepared electrocatalysts were determined using scanning electron microscopy, energy-dispersive X-ray, and X-ray photoelectron spectroscopy techniques. Here, the trimetallic CuZnCo nanoparticles were synthesized as a powerful redox probe and highly efficient signal amplifier for the electrochemical oxidation of tryptophan. Differential pulse voltammetry studies showed a linear relationship with a tryptophan concentration of 5-230 μM, and the low detection limit was identified at 1.1 μM with a sensitivity of 0.1831 μA μM-1 cm-2.

Intense Blue Photo Emissive Carbon Dots Prepared through Pyrolytic Processing of Ligno-Cellulosic Wastes

In this work, Carbon Dots with intense blue photo-luminescent emission were prepared through a pyrolytic processing of forestry ligno-cellulosic waste. The preparation path is simple and straightforward, mainly consisting of drying and fine grinding of the ligno-cellulosic waste followed by thermal exposure and dispersion in water. The prepared Carbon Dots presented characteristic excitation wavelength dependent emission peaks ranging within 438-473 nm and a remarkable 28% quantum yield achieved at 350 nm excitation wavelength. Morpho-structural investigations of the prepared Carbon Dots were performed through EDX, FT-IR, Raman, DLS, XRD, and HR-SEM while absolute PLQY, steady state, and lifetime fluorescence were used to highlight their luminescence properties. Due to the wide availability of this type of ligno-cellulosic waste, an easy processing procedure achieved photo-luminescent properties, and the prepared Carbon Dots could be an interesting approach for various applications ranging from sensors, contrast agents for biology investigations, to photonic conversion mediums in various optoelectronic devices. Additionally, their biocompatibility and waste valorization in new materials might be equally good arguments in their favor, bringing a truly "green" approach.

Microporous Polymelamine Framework Functionalized with Re(I) Tricarbonyl Complexes for CO2 Absorption and Reduction

A mixture of polymeric complexes based on the reaction between Re(CO)₅Cl and the porous polymeric network coming from the coupling of melamine and benzene-1,3,5-tricarboxaldehyde was obtained and characterized by FTIR, NMR, SEM, XPS, ICP, XRD, and cyclic voltammetry (CV). The formed rhenium-based porous hybrid material reveals a noticeable capability of CO₂ absorption. The gas absorption amount measured at 295 K was close to 44 cm³/g at 1 atm. An interesting catalytic activity for CO₂ reduction reaction (CO₂RR) is observed, resulting in a turn over-number (TON) close to 6.3 under 80 min of test at -1.8 V vs. Ag/AgCl in a TBAPF₆ 0.1 M ACN solution. A possible use as filler in membranes or columns can be envisaged.

Synthesis and Characterization of New Ferrite-Lignin Hybrids

The paper presents the synthesis and characterization of new cobalt ferrite-lignin hybrids. The hybrids were obtained through the combustion of cobalt nitrate and ferric nitrate, two kinds of lignin being used as combustion agents. The temperatures of calcination were 500 °C and 900 °C, respectively. The hybrids were characterized by Fourier transform infrared spectroscopy (FT-IR), X-ray powder diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray (EDX), and X-ray photoelectron spectroscopy (XPS). The magnetic properties were also assessed by vibrating sample magnetometer system (VSM). This facile synthesis method made it possible to obtain cobalt ferrite-lignin hybrids with a spinel structure. Their particle sizes and crystallite sizes have increased with an increment in the calcination temperature. A different occupancy of cations at octahedral and tetrahedral sites also occurred upon the increase in temperature. The hybrids comprising organic lignin presented the best magnetic properties.

All-polysaccharide hydrogels for drug delivery applications: Tunable chitosan beads surfaces via physical or chemical interactions, using oxidized pullulan

The present work reports a versatile approach to the manufacture of chitosan beads with tunable pore size and targeted properties. To achieve this, the as prepared chitosan beads were allowed to interact with aqueous solutions of two types of oxidized pullulan derivatives. Depending on the functional groups present on the pullulan structure after oxidation, i.e., carboxyl or aldehyde, covalent or physical hybrid hydrogels could be prepared. The attachment of oxidized pullulan onto chitosan structure was checked by FTIR, RMN, XPS and thermal analysis. The morphology of the hybrid structures was evaluated by using Scanning Electron Microscopy (SEM). After structural evaluations, all the prepared hydrogels were characterized by means of dynamic vapor sorption and swelling degree studies, exhibiting a Case-II swelling mechanism. Drug model compounds, such as ibuprofen, bacitracin and neomycin were used for drug loading and release assays, proving high drug loading capacity and tunable release behavior. Drug loaded beads exhibited antibacterial activity and hemocompatibility experiments indicated no coagulation phenomena.

Raman Spectroscopy, X-ray Diffraction, and Scanning Electron Microscopy as Noninvasive Methods for Microstructural Alterations in Psoriatic Nails

Psoriasis is a chronic inflammatory disease associated with immune system dysfunction that can affect nails, with a negative impact on patient life quality. Usually, nail psoriasis is associated with skin psoriasis and is therefore relatively simple to diagnose. However, up to 10% of nail psoriasis occurs isolated and may be difficult to diagnose by means of current methods (nail biopsy, dermoscopy, video dermoscopy, capillaroscopy, ultrasound of the nails, etc.). Since the nail is a complex biological tissue, mainly composes of hard α-keratins, the structural and morphological techniques can be used to analyze the human fingernails. The aim of this study was to corroborate the information obtained using Raman spectroscopy with those obtained by scanning electron microscopy (SEM) and X-ray diffractometry and to assess the potential of these techniques as non-invasive dermatologic diagnostic tools and an alternative to current methods.

NHF-derived carbon dots: prevalidation approach in breast cancer treatment

Metastatic breast cancer dominates the female cancer-related mortality. Tumour-associated molecules represents a crucial for early disease detection and identification of novel therapeutic targets. Nanomaterial technologies provide promising novel approaches to disease diagnostics and therapeutics. In the present study we extend the investigations of antitumoral properties of Carbon Dots prepared from N-hydroxyphthalimide (CD-NHF) precursor. We evaluate the effect of CD-NHF on tumour cell migration and invasion in vitro and their impact on tumour progression using an in vivo model. Furthermore, we investigate the molecular mechanisms involved in CD-NHF antitumour effects. In vivo mammary tumours were induced in Balb/c female mice by injecting 4T1 cells into the mammary fat pad. Conditional treatment with CD-NHF significantly impair both migration and invasion of metastatic breast cancer cells. The presence of CD-NHF within the 3D cell cultures strongly inhibited the malignant phenotype of MDA-MB-231, 4T1 and MCF-7 cells in 3D culture, resulting in culture colonies lacking invasive projections and reduction of mammospheres formation. Importantly, breast tumour growth and metastasis dissemination was significantly reduced upon CD-NHF treatments in a syngeneic mouse model and is associated with down-regulation of Ki67 and HSP90 expression. CD-NHF nanostructures provide exciting perspective for improving treatment outcome in breast cancer.

Effect of TAT-DOX-PEG irradiated gold nanoparticles conjugates on human osteosarcoma cells

The paper aims to investigate the cytotoxic effect on tumor cells of irradiated AuNPs in green light and subsequently functionalized with HS-PEG-NH2. The toxicity level of gold conjugates after their functionalization with DOX and TAT peptide was also evaluated. The AuNPs were prepared using the modified Turkevich method and exposed to visible light at a wavelength of 520 nm prior their PEGylation. The optical properties were analyzed by UV-vis spectroscopy, the surface modification was investigated using FTIR and XPS spectroscopies and their sizes and morphologies were evaluated by TEM and DLS techniques. DOX and TAT peptide were linked to the surface of PEGylated AuNPs by reacting their amino groups with glycidyloxypropyl of PEGylated DOX or TAT conjugates under mild conditions at room temperature and in the presence of ethanol as catalyst. The conjugates containing DOX or DOX and TAT have been characterized by fluorescence and FTIR techniques. The changes of electrochemical features were observed using cyclic voltammetry, suggesting a better stability of irradiated nanoparticles. By mass spectrometry it was confirmed that the compounds of interest were obtained. The cell viability test showed that irradiated and non-irradiated nanoparticles coated with PEG are not toxic in normal cells. Tumor cell viability analysis showed that the PEGylated nanoparticles modified with DOX and TAT peptide were more effective than pristine DOX, indicating cytotoxicity up to 10% higher than non-irradiated ones.

New insights into human hair: SAXS, SEM, TEM and EDX for Alopecia Areata investigations

Background

Alopecia areata (AA) is a T-cell-mediated autoimmune disease and affects up to 2% of the population. There is a need for a more profound and rigorous understanding of the structure and composition of human hair affected by AA in order to manage this disease. The aim of this article is to understand the effects of AA on the structure and composition of human hair.

Methods

Several physico-chemical investigation methods, such as Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), Energy-Dispersive X-ray Spectroscopy (EDX), and microbeam Small Angle X-ray Scattering (SAXS), were used to analyze human hair samples obtained from healthy donors and patients with AA.

Results

SEM revealed more severe hair surface defects for the white regrown hair (W-AA) samples. TEM showed the presence of air-like vesicles located in the endocuticle of regrown hair. Analysis of ultrathin sections of W-AA showed the existence of empty vesicles and smaller melanin granules compared to control samples. SAXS demonstrated that unaffected hair of patients with AA (B-AA) and W-AA melanin aggregates are different in their sizes and shapes compared to the control samples. EDX data showed that W-AA elemental composition was significantly different from the other sample groups. Our study showcases promising non-invasive techniques for a better and more accurate understanding of changes in the internal structure and composition of hair affected by AA.

Probing the supramolecular features via π–π interaction of a di-iminopyrene-di-benzo-18-crown-6-ether compound: experimental and theoretical study

Herein, we report the formation of a potential supramolecular arrangement mediated by inter- and intra-molecular interactions between di-iminopyrene-dibenzo-18-crown-6-ether molecules.

In Vitro and In Vivo Antioxidant Activity of the New Magnetic-Cerium Oxide Nanoconjugates

BACKGROUND

Cerium oxide nanoparticles present the mimetic activity of superoxide dismutase, being able to inactivate the excess of reactive oxygen species (ROS) correlated with a large number of pathologies, such as stents restenosis and the occurrence of genetic mutations that can cause cancer. This study presents the synthesis and biological characterisation of nanoconjugates based on nanoparticles of iron oxide interconnected with cerium oxide conjugates.

METHODS

The synthesis of magnetite-nanoceria nanoconjugates has been done in several stages, where the key to the process is the coating of nanoparticles with polyethyleneimine and its chemical activation-reticulation with glutaraldehyde. The nanoconjugates are characterised by several techniques, and the antioxidant activity was evaluated in vitro and in vivo.

RESULTS

Iron oxide nanoparticles interconnected with cerium oxide nanoparticles were obtained, having an average diameter of 8 nm. Nanoconjugates prove to possess superparamagnetic properties and the saturation magnetisation varies with the addition of diamagnetic components in the system, remaining within the limits of biomedical applications. In vitro free-radical scavenging properties of nanoceria are improved after the coating of nanoparticles with polyethylenimine and conjugation with magnetite nanoparticles. In vivo studies reveal increased antioxidant activity in all organs and fluids collected from mice, which demonstrates the ability of the nanoconjugates to reduce oxidative stress.

CONCLUSION

Nanoconjugates possess magnetic properties, being able to scavenge free radicals, reducing the oxidative stress. The combination of the two properties mentioned above makes them excellent candidates for theranostic applications.

Hyperpolarised NMR to follow water proton transport through membrane channels via exchange with biomolecules

Water uptake in vesicles and the subsequent exchange between water protons and amide -NH protons in amino acids can be followed by a new, highly sensitive, type of magnetic resonance spectroscopy: dynamic nuclear polarisation (DNP)-enhanced NMR in the liquid state. Water hydrogen atoms are detected prior to and after their transfer to molecular sites in peptides and proteins featuring highly-accessible proton-exchangeable groups, as is the case for the -NH groups of intrinsically disordered proteins. The detected rates for amide proton-water proton exchange can be modulated by membrane-crossing rates, when a membrane channel is interposed. We hyperpolarised water proton spins via dynamic nuclear polarisation followed by sample dissolution (d-DNP) and transferred the created polarisation to -NH groups with high solvent accessibility in an intrinsically disordered protein domain. This domain is the membrane anchor of c-Src kinase, whose activity controls cell proliferation. The hindrance of effective water proton transfer rate constants observed in free solvent when a membrane-crossing step is involved is discussed. This study aims to assess the feasibility of recently-introduced hyperpolarised (DNP-enhanced) NMR to assess water membrane crossing dynamics.

Sequencing batch biosorption of micropollutants from aqueous effluents by rapeseed waste: Experimental assessment and statistical modelling

Rapeseed (RS) waste was used for sequential biosorption from aqueous solutions of two target micropollutants: lead ions and Reactive blue 19 (Rb19) dye, through an integrated approach, combining experimental assessment and statistical modeling. In both cases of sequential biosorption, a pseudo-second order kinetic model fitted the biosorption data well. Intraparticle diffusion proved to be the rate-limiting step in the sequential retention of both micropollutants. A selective desorption of metal ions and anionic dye at pH 2.5 and 10.5, respectively was observed. The quadratic models generated by response surface methodology (RSM) adequately described the sequential biosorption process and the desorption process, respectively. XPS and FTIR analysis indicated the mechanisms involved in the retention of target pollutants.

Erosion as a possible mechanism for the decrease of size of plastic pieces floating in oceans

A sea water wave tank fitted in an artificial UV light weathering chamber was built to study the behaviour of polypropylene (PP) injected pieces in close ocean-like conditions. In air, the same pieces sees a degradation in the bulk with a decrease of mechanical properties, a little change of crystal properties and nearly no change of surface chemistry. Weathering in the sea water wave tank shows only a surface changes, with no effect on crystals or mechanical properties with loss of small pieces of matter in the sub-micron range and a change of surface chemistry. This suggests an erosion dispersion mechanism. Such mechanism could explain why no particle smaller than about one millimeter is found when collecting plastic debris at sea: there are much smaller, eroded from plastic surfaces by a mechano-chemical process similar to the erosion mechanism found in the dispersion of agglomerate under flow.

Superparamagnetic Composites Based on Ionic Resin Beads/CaCO3 /Magnetite

The preparation of superparamagnetic composites obtained by CaCO₃ mineralization from supersaturate aqueous solutions is presented. The preparation was conducted in the presence of oleic acid stabilized magnetite nanoparticles as a water-based magnetic fluid and insoluble templates as gel-like cross-linked polymeric beads. The presence of the magnetic particles in the composites provides a facile way for external manipulation using a permanent magnet, thus allowing the separation and extraction of magnetically modified materials. Two ion exchangers based on divinylbenzene/ethyl acrylate/acrylonitrile cross-linked copolymer-a cation ion exchanger (CIE) and an amphoteric ion exchanger (AIE)-were used, as well as different addition orders of magnetite and CaCO₃ crystals growth precursors. The morphology of the composites was investigated by SEM, the polymorphs content by X-ray diffraction, and the thermal stability by thermogravimetric analysis. Polymer, CaCO₃ , and magnetite in the composite particles were shown to be present by energy dispersive X-ray (EDX), XPS, and TEM. The sorption capacity for Cu^II ions was tested, as compared to samples prepared without magnetite.

Lactoferrin-Immobilized Surfaces onto Functionalized PLA Assisted by the Gamma-Rays and Nitrogen Plasma to Create Materials with Multifunctional Properties

Both cold nitrogen radiofrequency plasma and gamma irradiation have been applied to activate and functionalize the polylactic acid (PLA) surface and the subsequent lactoferrin immobilization. Modified films were comparatively characterized with respect to the procedure of activation and also with unmodified sample by water contact angle measurements, mass loss, X-ray photoelectron spectroscopy (XPS), attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR), atomic force microscopy (AFM), and chemiluminescence measurements. All modified samples exhibit enhanced surface properties mainly those concerning biocompatibility, antimicrobial, and antioxidant properties, and furthermore, they are biodegradable and environmentally friendly. Lactoferrin deposited layer by covalent coupling using carbodiimide chemistry showed a good stability. It was found that the lactoferrin-modified PLA materials present significantly increased oxidative stability. Gamma-irradiated samples and lactoferrin-functionalized samples show higher antioxidant, antimicrobial, and cell proliferation activity than plasma-activated and lactoferrin-functionalized ones. The multifunctional materials thus obtained could find application as biomaterials or as bioactive packaging films.

Nail Damage (Severe Onychodystrophy) Induced by Acrylate Glue: Scanning Electron Microscopy and Energy Dispersive X-Ray Investigations

BACKGROUND

Scanning electron microscopy (SEM) and energy dispersive X-ray (EDX) techniques have been used in various fields of medical research, including different pathologies of the nails; however, no studies have focused on obtaining high-resolution microscopic images and elemental analysis of disorders caused by synthetic nails and acrylic adhesives.

METHODS

Damaged/injured fingernails caused by the use of acrylate glue and synthetic nails were investigated using SEM and EDX methods.

RESULTS

SEM and EDX proved that synthetic nails, acrylic glue, and nails damaged by contact with acrylate glue have a different morphology and different composition compared to healthy human nails.

CONCLUSIONS

SEM and EDX analysis can give useful information about the aspects of topography (surface sample), morphology (shape and size), hardness or reflectivity, and the elemental composition of nails.

Photoluminescent polymer composites with R, G, B emission and their potential applications in LCD displays

Photoluminescent polymer composites with RGB emission were prepared, investigated and tested in a configuration which could replace the usual RGB filters in AMLCD displays.

Plasma-activated fibrinogen coatings onto poly(vinylidene fluoride) surface for improving biocompatibility with tissues

CO2, N2, and N2/H2 radiofrequency plasma exposure was used for functionalization of poly(vinylidene fluoride) surface aiming the fibrinogen immobilization. Fibrinogen was immobilized onto poly(vinylidene fluoride) surface using both simple plasma activation and covalent coupling. The modified surfaces have been characterized by X-ray photoelectron spectroscopy, attenuated total reflectance–Fourier transform infrared spectroscopy, near infrared–chemical imaging, atomic force microscopy, and wettability measurements, and the obtained materials were tested as supports for fibroblast cell cultures. The plasma type and the immobilization procedure have influenced the fibrinogen attachment onto the poly(vinylidene fluoride) surface, which was achieved mainly through amide bonds when using coupling agents. Covalent immobilization of fibrinogen onto poly(vinylidene fluoride) surface leads to a more stable protein-modified polymer surface. Non-cytotoxic plasma-based coating technology has the ability to covalently immobilize bioactive molecules for surface modification of some biomaterials that mainly could be achieved by the immobilization of proteins such as fibrinogen that triggers desirable cellular responses. The fibrinogen-modified poly(vinylidene fluoride) materials showed increased cell viability of fibroblasts. Cell viability was enhanced by plasma-activated fibrinogen coatings onto poly(vinylidene fluoride) surface, this being more significant if coating was linked further by a coupling reaction. Hence, they could be good candidates for biomedical applications.

Dynamic constitutional frameworks (DCFs) as nanovectors for cellular delivery of DNA

We introduce Dynamic Constitutional Frameworks (DCFs), macromolecular structures that efficiently bind and transfect double stranded DNA. DCFs are easily synthesizable adaptive 3D networks consisting of core connection centres reversibly linked via labile imine bonds both to linear polyethyleneglycol (PEG, ∼1500 Da) and to branched polyethyleneimine (bPEI, ∼800 Da). DCFs bind linear and plasmid DNA, forming particulate polyplexes of 40-200 nm in diameter. The polyplexes are stable during gel electrophoresis, well tolerated by cells in culture, and exhibit significant transfection activity. We show that an optimal balance of PEG and bPEI components is important for building DCFs that are non-toxic and exhibit good cellular transfection activity. Our study demonstrates the versatility and effectiveness of DCFs as promising new vectors for DNA delivery.

Collagen immobilization on ultraviolet light-treated poly(ethylene terephthalate)

The present article is focused on the studies regarding the effects of ultraviolet (UV) light on poly(ethylene terephthalate) (PET) films surfaces using scanning electron microscopy (SEM), Fourier transform infrared, X-ray photoelectron spectrometry (XPS), and atomic force microscopy (AFM) measurements, subsequent to collagen immobilization. UV treatment influences the surface energy of polymers as the result of the polymer chain breaking, followed by insertion of oxygen-containing functional groups. Accordingly, after UV light treatment, collagen was adsorbed on the PET surfaces in different proportions. Significant changes in the surface topography appeared after collagen immobilization on UV-treated PET films, and they were put in evidence by SEM and tapping-mode AFM experiments. XPS measurements demonstrated the adsorption of collagen on PET UV light-altered surfaces by increasing of nitrogen content. The cytocompatibility tests using stem cells have shown good results for all treated polymers.

Functional silsesquioxane-based hierarchical assemblies for antibacterial/antifungal coatings

This paper reports the first study on functional silsesquioxane-based hierarchical assemblies containing an ordered distribution of silver nanoparticles with a large number of {111} facets, obtained through sol–gel reaction, intended for antibacterial/antifungal coatings.

Hybrid fullerene conjugates as vectors for DNA cell-delivery

C60-PEI and C60-PEG-PEI as efficient binders of dsDNA, with good transfection up to 25%, high cytocompatibility and cell proliferation up to 200%.

Heparin-anthranoid conjugates associated with nanomagnetite particles and their cytotoxic effect on cancer cells

The paper describes a methodology for preparing monodisperse, water-soluble magnetite nanoparticles, coated with heparin and loaded with 4,5-dihydroxy-9,10-dioxoanthracene-2-carboxylic acid (Rhein), able to be used as a drug delivery system for cancer chemotherapy. Upon preparation, nanoparticles structure and morphology were investigated. The surface charge and the equivalent dimensions of the nanoparticles dispersed in water were measured, as a function of the suspension pH. The concentration of the drug into the nanoparticles shell, and the drug release profile was determined. The functionality of Rhein-loaded heparin-coated magnetic nanoparticles was assessed by monitoring their cytotoxic effect on cultured human tumor hepatocyte cell line, HepG2, using MTT assay. We found that upon exposure of HepG2 cells to Rhein-loaded heparin-coated nanoparticles, the cell viability was drastically reduced (to approximately 10%) as compared to that of the cells exposed to the free drug, indicating the potential of these magnetite nanoparticles to be used in cancer therapy.

Theoretical study on β-cyclodextrin inclusion complexes with propiconazole and protonated propiconazole

The synthesis of the β-cyclodextrin/propiconazole nitrate inclusion complex and the advantages of the encapsulation of this drug were recently reported, but the experimental data only partially revealed the structure of the supramolecular complex due to the limitations in understanding the intermolecular association mechanism. The present work describes the equilibrium molecular geometries of β-cyclodextrin/propiconazole and β-cyclodextrin/protonated propiconazole, established by the AM1 and PM3 semi-empirical methods. The affinity between different parts of the guest molecule and the cyclodextrin cavity was studied considering that propiconazole possesses three residues able to be included into the host cavity through primary or secondary hydroxyl rims. The results have revealed that the most stable complex is formed when the azole residue of the propiconazole enters the cavity of the cyclodextrin through the narrow hydroxyl’s rim.