Gold Nanoparticles Functionalized with 2-Thiouracil for Antiproliferative and Photothermal Therapies in Breast Cancer Cells

Nanoparticles have been used to transport drugs to various body parts to treat cancer. Our interest is in gold nanoparticles (AuNPs) since they have the capacity to absorb light and convert it to heat, inducing cellular damage. This property is known as photothermal therapy (PTT) and has been studied in cancer treatment. In the present study, biocompatible citrate-reduced AuNPs were functionalized with a biologically active compound, 2-thiouracil (2-TU), of potential anticancer activity. Both the unfunctionalized (AuNPs) and functionalized (2-TU-AuNPs) were purified and characterized by UV-Vis absorption spectrophotometry, Zeta potential, and Transmission Electron Microscopy. Results showed monodispersed, spherical AuNPs with a mean core diameter of 20 ± 2 nm, a surface charge of -38 ± 5 mV, and a localized surface plasmon resonance peak at 520 nm. As a result of functionalization, the mean core diameter of 2-TU-AuNPs increased to 24 ± 4 nm, and the surface charge increased to -14 ± 1 mV. The functionalization of AuNPs and the load efficiency were further established through Raman spectroscopy and UV-Vis absorption spectrophotometry. The antiproliferative activities of AuNPs, 2-TU and 2-TU-AuNPs were examined by a 3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide (MTT) assay in the MDA-MB-231 breast cancer cell line. It was established that AuNPs significantly enhanced the antiproliferative activity of 2-TU. Furthermore, the irradiation of the samples with visible light at 520 nm decreased the half-maximal inhibitory concentration by a factor of 2. Thus, the 2-TU drug concentration and its side effect during treatments could be significantly reduced by synergistically exploiting the antiproliferative activity of 2-TU loaded onto AuNPs and the PTT effect of AuNPs.

Understanding COVID-19 Situation in Nepal and Implications for SARS-CoV-2 Transmission and Management

BACKGROUND

The pandemic of Coronavirus Disease 2019 (COVID-19), one of the most infectious diseases in the modern history, is caused by Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) and has had a profound health and economic toll, globally. This paper identifies the overall health status associated with COVID-19 pandemic in all 7 provinces of Nepal, a developing country in South Asia, analyzing data from January 2020 to February 2022. It focuses on the SARS-CoV-2 prevalence, transmission through wastewater and other routes, diagnostics, treatment options, and alternative medicines, thereby offering key perspectives for its management.

MATERIALS AND METHODS

Studies regarding coronavirus spanning the 2017 to 2022 period were searched on the web, Nepalese database, and Web of Science. Refined criteria included SARS-CoV-2 in wastewater of Nepal or worldwide. Demographic data (sex, age-group, and geographic location) were also obtained from websites and relevant reports of the Ministry of Health and Population (MOHP) of Nepal, ranging from January 2020 to February 2022. Moreover, trends concerning lockdown, business, and border activities in Nepal between February 2020 and October 2020 were evaluated. The viral dissemination pathways, diagnosis, and available treatment options, including the Ayurvedic medicine, were also examined.

RESULTS

Aerosols generated during the hospital, industrial, recreational, and household activities were found to contribute to the propagation of SARS-CoV-2 into environmental wastewater, thereby putting the surrounding communities at risk of infection. When lockdown ended and businesses opened in October 2020, the number of active cases of COVID-19 increased exponentially. Bagmati Province had the highest number of cases (53.84%), while the remaining 6 provinces tallied 46.16%. Kathmandu district had the highest number of COVID-19 cases (138, 319 cases), while Manang district had the smallest number of infections (81 cases). The male population was found to be predominantly infected (58.7%). The most affected age groups were the 31 to 40 years old males (25.92%) and the 21 to 30 years old females (26.85%).

CONCLUSION

The pandemic impacted the public health and economic growth in our study duration. SARS-CoV-2 was prevalent in the wastewater of Nepal. The Terai districts and the megacities were mostly affected by SARS-CoV-2 infections. Working-age groups and males were identified as the highest risk groups. More investigations on the therapeutic and alternative cures are recommended. These findings may guide the researchers and professionals with handling the COVID-19 challenges in developing countries such as Nepal and better prepare for future pandemics.

Thermosensitive Betulinic Acid-Loaded Magnetoliposomes: A Promising Antitumor Potential for Highly Aggressive Human Breast Adenocarcinoma Cells Under Hyperthermic Conditions

PURPOSE

Breast cancer presents one of the highest rates of prevalence around the world. Despite this, the current breast cancer therapy is characterized by significant side effects and high risk of recurrence. The present work aimed to develop a new therapeutic strategy that may improve the current breast cancer therapy by developing a heat-sensitive liposomal nano-platform suitable to incorporate both anti-tumor betulinic acid (BA) compound and magnetic iron nanoparticles (MIONPs), in order to address both remote drug release and hyperthermia-inducing features. To address the above-mentioned biomedical purposes, the nanocarrier must possess specific features such as specific phase transition temperature, diameter below 200 nm, superparamagnetic properties and heating capacity. Moreover, the anti-tumor activity of the developed nanocarrier should significantly affect human breast adenocarcinoma cells.

METHODS

BA-loaded magnetoliposomes and corresponding controls (BA-free liposomes and liposomes containing no magnetic payload) were obtained through the thin-layer hydration method. The quality and stability of the multifunctional platforms were physico-chemically analysed by the means of RAMAN, scanning electron microscopy-EDAX, dynamic light scattering, zeta potential and DSC analysis. Besides this, the magnetic characterization of magnetoliposomes was performed in terms of superparamagnetic behaviour and heating capacity. The biological profile of the platforms and controls was screened through multiple in vitro methods, such as MTT, LDH and scratch assays, together with immunofluorescence staining. In addition, CAM assay was performed in order to assess a possible anti-angiogenic activity induced by the test samples.

RESULTS

The physico-chemical analysis revealed that BA-loaded magnetoliposomes present suitable characteristics for the purpose of this study, showing biocompatible phase transition temperature, a diameter of 198 nm, superparamagnetic features and heating capacity. In vitro results showed that hyperthermia induces enhanced anti-tumor activity when breast adenocarcinoma MDA-MB-231 cells were exposed to BA-loaded magnetoliposomes, while a low cytotoxic rate was exhibited by the non-tumorigenic breast epithelial MCF 10A cells. Moreover, the in ovo angiogenesis assay endorsed the efficacy of this multifunctional platform as a good strategy for breast cancer therapy, under hyperthermal conditions. Regarding the possible mechanism of action of this multifunctional nano-platform, the immunocytochemistry of the MCF7 and MDA-MB-231 breast carcinoma cells revealed a microtubule assembly modulatory activity, under hyperthermal conditions.

CONCLUSION

Collectively, these findings indicate that BA-loaded magnetoliposomes, under hyperthermal conditions, might serve as a promising strategy for breast adenocarcinoma treatment.

Benign zinc oxide betaine-modified biochar nanocomposites for phosphate removal from aqueous solutions

Phosphate is one of the most costly and complex environmental pollutants that leads to eutrophication, which decreases water quality and access to clean water. Among different adsorbents, biochar is one of the promising adsorbents for phosphate removal as well as heavy metal removal from an aqueous solution. In this study, biochar was impregnated with nano zinc oxide in the presence of glycine betaine. The Zinc Oxide Betaine-Modified Biochar Nanocomposites (ZnOBBNC) proved to be an excellent adsorbent for the removal of phosphate, exhibiting a maximum adsorption capacity of phosphate (265.5 mg. g^-1) and fast adsorption kinetics (~100% removal at 15 min at 10 mg. L^-1 phosphate and 3 g. L^-1 nanocomposite dosage) in phosphate solution. The synthesis of these benign ZnOBBNC involves a process that is eco-friendly and economically feasible. From material characterization, we found that the ZnOBBNC has ~20-30 nm particle size, high surface area (100.01 m². g^-1), microporous (25.79 Å) structures, and 7.64% zinc content. The influence of pH (2-10), coexisting anions (Cl^-, CO₃^2-, NO₃^- and SO₄^3-), initial phosphate concentration (10-500 mg. L^-1), and ZnOBBNC dosage (0.5-5 g. L^-1) were investigated in batch experiments. From the adsorption isotherms data, the adsorption of phosphate using ZnOBBNC followed Langmuir isotherm (R² = 0.9616), confirming the mono-layered adsorption mechanism. The kinetic studies showed that the phosphate adsorption using ZnOBBNC followed the pseudo-second-order model (R² = 1.0000), confirming the chemisorption adsorption mechanism with inner-sphere complexion. Our results demonstrated ZnOBBNC as a suitable, competitive candidate for phosphate removal from both mock lab-prepared and real field-collected wastewater samples when compared to commercial nanocomposites.

In Vivo Biological Evaluation of Polyurethane Nanostructures with Ursolic and Oleanolic Acids on Chemically-induced Skin Carcinogenesis

BACKGROUND/AIM

Oleanolic and ursolic acids (OA and UA) are two pentacyclic triterpenes, ubiquitously spread in plants, previously known for their chemopreventive capacity on different types of cancer. The major pharmacological disadvantage of these phytocompounds is their poor water solubility, which often limits their applicability.

MATERIALS AND METHODS

Using the interfacial polycondensation combined with spontaneous emulsification technique, polyurethane nanostructures (PU) were synthetized in order to improve this problem. In order to test the in vivo chemopreventive potential of the two pure compounds, as well as the encapsulated compounds in PU used as drug carriers, a chemically-induced skin carcinogenesis model was constructed.

RESULTS

UA and OA have a moderate chemopreventive activity against tumors induced by 7,12-dimethylbenzantracene (DMBA) and 12-O-tetradecanoilphorbol-13-acetate (TPA) application. Incorporation of active agents in PU did not lead to increased chemopreventive effect.

CONCLUSION

PU is not a suitable formulation of UA and OA.

A Comparison Of The Improving In Major Depressive Symptoms As Reported By Romanian Physicians And Patients In a Prospective, Multicenter, Observational Study

Introduction

Depression leads to substantial suffering for the patients, their families and becomes an economic burden for system [1,2]. Patients and clinicians tend to rate the remission differently [3].

Objectives and methods

We investigate if clinicians and patients rate different the treatment response. This study assed the evolution of major depressive episode (MDE) in patients treated with Agomelatine, in Romania. It was designed as a multicentre, observational study that included 1213 adult patients evaluated in 75 sites in 2014. The design included 3 visits (baseline (V1); visit at 2/3 weeks (V2); visit 6/8 weeks (V3)). The scales used were: MADRS, SHAPS, CGI-I, CGI-S, PGI-I, PGI-S.

Results

The MDE improvement was significant (P < 0.001) for all aspects evaluated. At baseline, more clinicians vs. patients considered the moderately or markedly ill as best descriptors of the state. The difference between the two assessments was even higher for V2 and V3. During V2 clinicians reported “minimally improvement” while patients reported “much improvement” in higher percentage. During V3, both, clinicians and patients reported a “very much improved” clinical status. Of the patients 42.60% reported at V3 “normal”, not at all ill’ in comparison to 34.81% of clinicians who reported the same (P < 0.001).

Conclusions

This could mean that patients are not aware of the severity of their disease. This data could be interpreted in the way that patients are more prone to rate higher the improvements as response to treatment and the clinicians to rate as response a more than 50% decrease of symptomatology.

References not available.

Disclosure of interest

The authors have not supplied their declaration of competing interest.

Label-Free SERS Detection of Small Proteins Modified to Act as Bifunctional Linkers

Two double-cysteine mutants of a small protein judiciously modified so that the cysteines appear at axially opposite sides of the native fold were prepared such that different axes were defined in the two mutants. Upon reduction, the disulfide bonds are broken, and the proteins act as bifunctional ligands toward Ag nanoparticles, encouraging their assembly into nanoparticle dimers and small aggregates such that, when excited with laser light, the proteins are automatically located at electromagnetic hot spots within the aggregates. Because the protein molecules are small (~2.3 nm) and because the electromagnetic energy at a hot spot tends to increase as the size of the interparticle gap decreases, this nanoparticle-protein-nanoparticle geometry significantly enhances the Raman emission at the metallic surface. Exploiting this effect, we have recorded surface-enhanced Raman spectra (SERS) of the proteins at near-single-molecule level. The observed SERS spectra were dominated by the vibrations of molecular groups near the anchor points of the proteins.

Detection of sequence-specific protein-DNA interactions via surface enhanced resonance Raman scattering

We developed a new strategy to detect protein-DNA binding through surface enhanced resonance Raman scattering (SERRS). Silver-plated DNA and gold nanoparticle assemblies were used to identify sequence-specific and concentration-dependent binding of a DNA cytosine-C5-methyltransferase and the eukaryotic transcriptional regulator, TATA binding protein. Proteins were identified through specific Raman-active labels, and affinities observed correlate well with those determined by other methods. Raman-active labeling and interchangeable DNA sequences create a platform for versatile investigation of multiprotein complexes.

Raman, Surface Enhanced Raman Spectroscopy, and DFT Calculations: A Powerful Approach for the Identification and Characterization of 5-Fluorouracil Anticarcinogenic Drug Species

The normal Raman and SERS spectra of 5-fluorouracil (5-FU) in water solution and attached to a biological artificial model (a silver colloid) at different pH values were recorded and discussed. The DFT calculation results helped us to establish for the first time the most stable resonance structure for each of the tautomeric forms (i.e., two enol and two enolate forms) and to interpret the Raman and SERS spectra. At alkaline pH, both deprotonated forms of 5-FU were found to be present in solution and to adsorb on the Ag surface in a perpendicular orientation or an orientation not significantly tilted from the surface normal. The N3-deprotonated form seems to be the dominant tautomer in the adsorbed state, more probably attached through the O7 atom. At acid pH values, the N3-deprotonated form was again found to be the mainly chemisorbed species adopting a similar orientation. The combination of these two approaches (i.e., the theoretical and experimental one) proved to be a viable candidate for inclusion in a rapid, sensitive biological method of detecting and studying such essential anticarcinogenic species or biological threats in different conditions.

DFT/TDDFT Studies of the Geometry, Electronic Structure and Spectra of (12S)-1,4,7,10-Tetraazadicyclo[10,3,0]-pentadecane-3,11-dione and Its Derivatives

The FT-Raman and UV-visible spectra of (12S)-1,4,7,10-tetraazadicyclo[10,3,0]-pentadecane-3,11-dione and its derivatives were obtained and discussed. The harmonic vibrational wavenumbers and the corresponding Raman scattering activities in their electronic ground-states were calculated at the DFT-B3LYP/6-31G(d) level of theory. The calculated wavenumbers were then scaled and compared with the experimental values. The 7-(2,4-dinitrophenyl)-(12S)-1,4,7,10-tetrazadicyclo[10,3,0]-pentadecane-3,11-dione derivative has mainly an amide (II) character, while the others have an amide (I) character. Moreover, the different substituents do not cause a significant shift of the vibrational mode of the macrocyclic plane. The electronic vertical excitation energy and the oscillator strength were determined with the help of TDDFT calculations and by employing pure (BLYP) and hybrid (B3LYP, B3P86, and mPW1PW91) functionals together with the 6-31G(d) basis set. The BLYP functional reproduces the UV-vis absorption spectra better than the B3LYP, B3P86, or mPW1PW91 hybrid functionals. A dimolecular model, which considers hydrogen-bonded structures, proved that strong inter- and intramolecular hydrogen bonds are present in these compounds. Due to the transannular effect, the UV-vis absorption spectrum of macrocyclic dioxotetraamines is completely different from that of single amide compounds.

A method for coupled transcription and aminoacylation of cysteinyl-tRNA

A novel method for coupled transcription and aminoacylation of transfer RNA was developed where Escherichia coli cysteine-specific tRNA (tRNA(cys)) was transcribed and aminoacylated in a single reaction. The cys-tRNA(cys) that was synthesized and aminoacylated using this method was functional in in vitro translation. The cys-tRNA(cys) was further modified with biotin (N-iodoacetyl-N-biotinhexylenediamine) to facilitate detection. The biotin-modified cys-tRNAs(cys) was also functional in in vitro translation, allowing the synthesis and detection of biotin-labeled protein.

Raman, SERS and theoretical studies of papaverine hydrochloride and its neutral species

Density functional theory (DFT) calculations and an experimental vibrational characterization of papaverine hydrochloride were performed. The computed structural parameters agree very well with the experimental values of the related crystal structure. The pH dependent Raman and SERS spectra of papaverine hydrochloride were recorded and discussed with the assistance of our theoretical results (harmonical vibrational wavenumbers, Raman scattering activities, total electron density and Natural Population Analysis of the molecule) and the SERS surface selection rules. Two different adsorption geometries were found for the corresponding evidenced species of papaverine, protonated and neutral, respectively.

Theoretical and pH dependent surface enhanced Raman spectroscopy study on caffeine

The surface enhanced Raman spectroscopy (SERS) spectrum of caffeine is recorded on a silver colloid at different pH values. It is discussed on the basis of the SERS "surface selection rules" in order to characterize its vibrational behavior on such a biological artificial model. To improve the previous assignments in the Raman spectrum and for a reliable, detailed analysis of SERS spectra, density functional theory calculations (structural parameters, harmonic vibrational wavenumbers, total electron density, and natural population analysis of the molecule) are performed for the anhydrous form of caffeine and the results are discussed. The predicted geometry and vibrational Raman spectra are in good agreement with the experimental data. The flat orientation of the mainly chemisorbed caffeine attached through the pi electrons and the lone pair of nonmethylated N atoms of the imidazole ring are proposed to occur at neutral and basic pH values. At acid pH values caffeine is probably adsorbed on the Ag surface through one or both oxygen atoms, more probably through the O atom of the conjugated carbonyl group with an end-on orientation. However, the changes in the overall SERS spectral pattern seem to indicate the electromagnetic mechanism as being the dominant one.

Fourier-transform Raman and infrared spectroscopic analysis of 2-nitro-tetraphenylporphyrin and metallo-2-nitro-tetraphenylporphyrins

The Fourier-transform Raman (FT-Raman) and infrared (FT-IR) spectra of 2-nitro-tetraphenylporphyrin (2-NO(2)-TPP), nickel-2-nitro-tetraphenylporphyrin (Ni-2-NO(2)-TPP), zinc-2-nitro-tetraphenylporphyrin (Zn-2-NO(2)-TPP) and copper-2-nitro-tetraphenylporphyrin (Cu-2-NO(2)-TPP) were acquired for the first time and carefully assigned and discussed. The effects of a beta-NO(2) group and the influence of the central metal on the molecular symmetry and vibrational spectra of the porphyrin macrocycle were also examined. The bands at 1323-1339, 1516-1526 and 961-971 cm(-1) were attributed to the symmetric and asymmetric stretching vibration of the NO(2) group and to the stretching vibration of the C(beta)-N bond, respectively, which connects the NO(2) group with the beta-carbon of the porphyrin macrocycle. These bands can act as a marker to distinguish beta-NO(2) TPPs from other beta-substituent TPPs. Cu-2-NO(2)-TPP has a C(4nu) molecular symmetry, which is different from those of Ni-2-NO(2)-TPP and Zn-2-NO(2)-TPP, i.e. D(4h).

Silylene-bridged dinuclear iron complexes [Cp(OC)2Fe]2SiX2 (X = H, F, Cl, Br, I). Synthesis, molecular structure, vibrational spectroscopy, and theoretical studies

The mu2-silylene-bridged iron complexes [Cp(OC)(2)Fe](2)SiX(2) (X = F (2), Br (4), I (5)) have been prepared from the mu2-SiH(2) functional precursor [Cp(OC)(2)Fe](2)SiH(2) (1) by hydrogen/halogen exchange, using HBF(4), CBr(4), and CH(2)I(2), respectively. The fluoro- and bromo-substituted derivatives 2 and 4 are converted upon UV irradiation to the carbonyl- and dihalosilylene-bridged dinuclear complexes [Cp(OC)Fe](2) (mu2-CO)(mu2-SiX(2)) (X = F (6), Br (7)) via CO elimination. All new compounds have been characterized spectroscopically, and, in addition, the molecular structure of 2, 4, and the previously reported chloro derivative [Cp(OC)(2)Fe](2)SiCl(2) (3) has been determined by single-crystal X-ray diffraction methods. For 1-5, the Fourier transform infrared and Raman spectra have been recorded and discussed, together with density functional theory calculations, which support the experimental results of the structural and vibrational analysis. The computed geometries, harmonic vibrational wavenumbers, and their corresponding Raman scattering activities are in good agreement with the experimental data. A significant dependence of the CO and Fe-Si stretching modes on the X substituents of the mu2-silylene bridge has been observed and discussed.

[Congenital craniofacial malformation]

The authors report a classification of the congenital malformations of the neuro- and visceral cranium, showing that they are generated by chromosomal aberrations. The meningoencephaloceles with oculo-orbital manifestations are numerous and have to be differentiated from other cystic formations. The radiologic examination, in the most incidences is very important in their diagnosis. These pseudotumours can be treated only surgically in the neurosurgery departments. This treatment might be an emergency or not, as a function of their site and the state of the mucosae on the tegumenta covering them.

[Shunt between Disse spaces and biliary canaliculi and its pathology]

The existence and permeability of communications between Disse spaces and biliary canaliculi has been finally accepted, in spite of the socalled obstacle of the water-tight junctions. The explanation of pigmented bile secretion by filtration and reabsorption has become plausible. Whilst other subtances excreted by the bile after having been filtered at the level of the sinusoidal wall need to enter the hepatic cell to be synthesised, stocked or to take up their final shape, the bile pigments, cell debris, cross the hepatic lobule through the shunt between the Disse space and the bile canaliculi, without passing through the liver cell. These facts require us today to reconsider the physiopathology of some liver disorders, especially those accompanied by jaundice.

[Dynamic epidemiology of diabetes mellitus (author's transl)]

Epidemiology as practiced to day has become outmoded. The authors propose a dynamic epidemiology, that is one applied throughout the country and which is in a stak of continuous development. This implies ascertainment of the major causes of diabetes : heredity and environment. Thus conceived, dynamic epidemiology can hope to tackle prevention in the prediabetic stage of a widespread chronic disease. A description is given of the method of application and a test of effectiveness.