Theoretical studies on the quercetin interactions in the oil-in-water F127 microemulsion: A DFT and MD investigation

Quercetin (Q) has attracted the attention of researchers for potential applications in advanced therapeutic treatments due to its antioxidant attributes and renal tissue improvement. F127-based oil-in-water microemulsions improved the bioavailability of Q and showed greater retention and more stable release. In this study, Q-loaded microemulsion was designed with the help of simulation techniques. The mechanism of action of Q was investigated in the bulk and microemulsion forms. The simulation results show the fast accumulation of Q molecules around 2,2-diphenyl-1-picrylhydrazyl (DPPH) molecules (free radicals) in bulk form and the slow accumulation of Q molecules around DPPH in microemulsion form. The stable release of Q in microemulsion form was found to be due to the powerful van der Waals (vdW) interactions between Q and F127. For a better and deeper understanding of the nature of mutual interactions between Q (enol and keto forms) and F127, quantum mechanical calculations were performed at the B3LYP/6-31G(d,p) level of theory. In particular, atoms in molecules (AIM) and natural bond orbital (NBO) analyses were performed to evaluate the strength of the interactions between Q and F127. The results showed that the formation of a strong hydrogen bond (HB) between Qenol and F127 stabilizes the microemulsion system and can contribute to the better performance of Q microemulsion compared to free Q in bulk

pH-Responsive PVA-Based Nanofibers Containing GO Modified with Ag Nanoparticles: Physico-Chemical Characterization, Wound Dressing, and Drug Delivery

Site-specific drug delivery and carrying repairing agents for wound healing purposes can be achieved using the intertwined three-dimensional structure of nanofibers. This study aimed to optimize and fabricate poly (vinyl alcohol) (PVA)-graphene oxide (GO)-silver (Ag) nanofibers containing curcumin (CUR) using the electrospinning method for potential wound healing applications. Fourier Transform Infrared (FTIR) spectrophotometry, X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM), Dynamic Light Scattering (DLS), and zeta potential were used to characterize the nanostructures. The mechanical properties of the nanostructures were subsequently examined by tensile strength and elongation test. As shown by MIC analysis of E. coli and S. aureus bacteria, the fabricated nanofibers had superior inhibitory effects on the bacteria growth. Ag nanoparticles incorporation into the nanofibers resulted in increased loading and encapsulation efficiencies from 21% to 56% and from 61% to 86%, respectively. CUR release from PVA/GO-Ag-CUR nanofiber at pH 7.4 was prevented, while the acidic microenvironment (pH 5.4) increased the release of CUR from PVA/GO-Ag-CUR nanofiber, corroborating the pH-sensitivity of the nanofibers. Using the in vitro wound healing test on NIH 3T3 fibroblast cells, we observed accelerated growth and proliferation of cells cultured on PVA/GO-Ag-CUR nanofibers

Detection of VIM-1 and IMP-1 genes in Klebsiella pneumoniae and relationship with biofilm formation

Klebsiella pneumoniae is an important human pathogen that is considered in recent years due to nosocomial infections resistant to treatment as well as the ability to form biofilms particularly in patients with urinary tract infection in ICU or hospital. The aim of this study was to evaluate the prevalence of VIM1, IMP1 genes and their ability to form biofilm in K. pneumoniae strains isolated from patients with urinary tract infection. In the study, using culture and biochemical methods, 1807 K. pneumoniae samples were isolated from patients with urinary tract infection hospitalized or referred to hospitals in Qom in 2013–2014. For isolation of MBL producing isolates, Double Disk Synergy Test (DDST) was used. Then MBL positive isolates were examined for the presence of VIM1, IMP1 genes using PCR method. Furthermore, all strains were investigated for biofilm formation by phenotypic microplate method. From 3165 urine samples cultured, 1807 isolates of K. pneumoniae were isolated and 109 strains (93.2%) were positive for MBL enzymes production. PCR results showed that the prevalence of VIM1 and IMP1 genes are 15.6 and 6.4%, respectively. The Phenotypic method indicated that 91.2% of isolates formed biofilm. Biofilm formation in K. pneumoniae isolates is high and there is a significant relationship between strong biofilm formation and prevalence of VIM1 and IMP1 genes. Also due to the presence of MBL genes in K. pneumoniae and horizontal transfer of genes to other bacteria, and to control the indiscriminate use of antibiotics, the hospital infection control methods must be considered

Oil-in-water microemulsion encapsulation of antagonist drugs prevents renal ischemia-reperfusion injury in rats

Developing new therapeutic drugs to prevent ischemia/reperfusion (I/R)-induced renal injuries is highly pursued. Liposomal encapsulation of spironolactone (SP) as a mineralocorticoid antagonist increases dissolution rate, bioavailability and prevents the drug from degradation. In this context, this work develops a new formulation of oil-in-water type microemulsions to enhance the bioavailability of SP. The size of the SP-loaded microemulsion was about 6.0 nm by dynamic light scattering analysis. Briefly, we investigated the effects of nano-encapsulated SP (NESP) on renal oxidative stress, biochemical markers and histopathological changes in a rat model of renal I/R injury. Forty eight male Wistar rats were divided into six groups. Two groups served as control and injury model (I/R). Two groups received “conventional” SP administration (20 mg/kg) and NESP (20 mg/kg), respectively, for two days. The remaining two groups received SP (20 mg/kg) and NESP (20 mg/kg) two days before induction of I/R. At the end of the experiments, serum and kidneys of rats underwent biochemical, molecular and histological examinations. Our results showed that I/R induces renal oxidative stress, abnormal histological features and altered levels of renal biomarkers. Administration of SP in healthy animals did not cause any significant changes in the measured biochemical and histological parameters compared to the control group. However, SP administration in the I/R group caused some corrections in renal injury, although it could not completely restore I/R-induced renal oxidative stress and kidney damage. On the contrary, NESP administration restored kidney oxidative injury via decreasing renal lipid peroxidation and enhancing glutathione, superoxide dismutase and catalase in kidneys of the I/R group. The deviated serum levels of urea, creatinine, total proteins and uric acid were also normalized by NESP administration. Furthermore, NESP protected against renal abnormal histology features induced by I/R. Therefore, NESP has beneficial effects in preventing kidney damage and renal oxidative stress in a rat model of I/R, which deserves further evaluations in the future

Efficiently Improving the Wi-Fi-Based Human Activity Recognition, Using Auditory Features, Autoencoders, and Fine-Tuning

Human activity recognition (HAR) based on Wi-Fi signals has attracted significant attention due to its convenience and the availability of infrastructures and sensors. Channel State Information (CSI) measures how Wi-Fi signals propagate through the environment. However, many scenarios and applications have insufficient training data due to constraints such as cost, time, or resources. This poses a challenge for achieving high accuracy levels with machine learning techniques. In this study, multiple deep learning models for HAR were employed to achieve acceptable accuracy levels with much less training data than other methods. A pre-trained encoder trained from a Multi-Input Multi-Output Autoencoder (MIMO AE) on Mel Frequency Cepstral Coefficients (MFCC) from a small subset of data samples was used for feature extraction. Then, fine-tuning was applied by adding the encoder as a fixed layer in the classifier, which was trained on a small fraction of the remaining data. The evaluation results (K-fold cross-validation and K=5) showed that using only 30% of the training and validation data (equivalent to 24% of the total data), the accuracy was improved by 17.7% compared to the case where the encoder was not used (with an accuracy of 79.3% for the designed classifier, and an accuracy of 90.3% for the classifier with the fixed encoder). While by considering more calculational cost, achieving higher accuracy using the pre-trained encoder as a trainable layer is possible (up to 2.4% improvement), this small gap demonstrated the effectiveness and efficiency of the proposed method for HAR using Wi-Fi signals

Advancements in tissue and organ 3D bioprinting: Current techniques, applications, and future perspectives

3D bioprinting techniques have emerged as a flexible tool in tissue engineering and regenerative medicine to fabricate or pattern functional 3D bio-structures with precise geometric designs, bridging the divergence between engineered and natural tissue constructs. A significantly increasing development has been achieved in understanding the relationship between the 3D-printing process and the structures, properties, and applications of the objects created. The ongoing advancement of novel biomaterial inks has enabled manufacturing of models and in vitro implants capable of achieving some level of success in preclinical trials. Remarkable progress in cell biology and biology-inspired computational design has assisted in achieving the latest milestone with planned tissue- or organ-like constructs having specific levels of functionality. However, biofabricated constructs still have a long way to go before reaching clinics. This review presents a picture of 3D bioprinting in the context of tissue engineering and regenerative medicine, with focus on biomaterials-related and design-centred aspects. Biomedical applications are described in detail in relation to major tissues or organs considered in the human body. Current technical limitations, challenges, future prospects and improvements are critically outlined and discussed

MOF-mediated synthesis of CuO/CeO2 composite nanoparticles: Characterization and estimation of the cellular toxicity against breast cancer cell line (MCF-7)

A copper oxide/cerium oxide nanocomposite (CuO/CeO2, NC) was synthesized via a novel method using a metal–organic framework as a precursor. This nanomaterial was characterized by Fourier transform infrared spectroscopy (FTIR), powder X-ray diffraction (PXRD), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), dynamic light scattering size analysis (DLS), and zeta potential. The PXRD showed the successful synthesis of the CuO/CeO2 NC, in which the 2theta values of 35.55◦ (d = 2.52 Å, 100%) and 38.73◦ (d = 2.32 Å, 96%) revealed the existence of copper (II) oxide. FTIR analysis showed the CeO2, hydroxyl groups, absorbed water, and some residual peaks. The solid phase analysis by FESEM and TEM images showed mean particle sizes of 49.18 ± 24.50 nm and 30.58 ± 26.40 nm, respectively, which were comparable with crystallite size (38.4 nm) obtained from PXRD, but it appears the CuO/CeO2 NC was not evenly distributed and in some areas, showed it was highly agglomerated. The hydrodynamic size (750.5 nm) also showed the agglomeration of the CuO/CeO2 NCs in the solution, which had a negatively charged surface. The CuO/CeO2 NCs showed anti-proliferative activity against human breast cancer cell line (MCF-7) in a dose-and time-dependence way, while affecting normal cells less significantly

Assessment of SnFe2O4 nanoparticles for potential application in theranostics: Synthesis, characterization, in vitro, and in vivo toxicity

In this research, tin ferrite (SnFe2O4 ) NPs were synthesized via hydrothermal route using ferric chloride and tin chloride as precursors and were then characterized in terms of morphology and structure using Fourier-transform infrared spectroscopy (FTIR), Ultraviolet–visible spectroscopy (UV-Vis), X-ray power diffraction (XRD), Scanning electron microscopy (SEM), Transmission electron microscopy (TEM), and Brunauer–Emmett–Teller (BET) method. The obtained UV-Vis spectra was used to measure band gap energy of as-prepared SnFe2O4 NPs. XRD confirmed the spinel structure of NPs, while SEM and TEM analyses disclosed the size of NPs in the range of 15–50 nm and revealed the spherical shape of NPs. Moreover, energy dispersive X-ray spectroscopy (EDS) and BET analysis was carried out to estimate elemental composition and specific surface area, respectively. In vitro cytotoxicity of the synthesized NPs were studied on normal (HUVEC, HEK293) and cancerous (A549) human cell lines. HUVEC cells were resistant to SnFe2O4 NPs; while a significant decrease in the viability of HEK293 cells was observed when treated with higher concentrations of SnFe2O4 NPs. Furthermore, SnFe2O4 NPs induced dramatic cytotoxicity against A549 cells. For in vivo study, rats received SnFe2O4 NPs at dosages of 0, 0.1, 1, and 10 mg/kg. The 10 mg/kg dose increased serum blood urea nitrogen and creatinine compared to the controls (P < 0.05). The pathology showed necrosis in the liver, heart, and lungs, and the greatest damages were related to the kidneys. Overall, the in vivo and in vitro experiments showed that SnFe2O4 NPs at high doses had toxic effects on lung, liver and kidney cells without inducing toxicity to HUVECs. Further studies are warranted to fully elucidate the side effects of SnFe2O4 NPs for their application in theranostics

Microencapsulation of Bacillus velezensis Using Alginate-Gum Polymers Enriched with TiO2 and SiO2 Nanoparticles

Bacillus bacteria are a group of plant growth stimulants that increase plant growth and resistance to plant pathogens by producing various metabolites. With their large surface area and small size, nanoparticles can be used in controlled-release formulations and increase the efficiency of the desired product. Encapsulation of biological agents in combination with nanoparticles can be an essential step in increasing the performance of these agents in adverse environmental conditions. In this study, which is the result of a collaboration between scientists from Italy and Iran, Bacillus velezensis was encapsulated in alginate combined with whey protein and zedo, mastic, and tragacanth gums in the presence of silica and titania nanoparticles to obtain two-layer and multilayer assemblies acting as novel, smart micro-encapsulation systems. The results of laboratory studies showed that the B. velezensis could produce protease, lipase, siderophore, auxin, and a dissolution of mineral phosphate. Scanning electron microscopy images (SEM) showed that the studied microcapsules were almost spherical. Moisture affinity, swelling, and efficiency of each microcapsule were examined. The results showed that the highest encapsulation efficiency (94.3%) was related to the multilayer formulation of alginate-whey protein-zedo. XRD and FTIR spectroscopy showed that the alginate, whey protein, and zedo were mixed properly and no incompatible composition occurred in the reaction. This study aimed to provide a suitable formulation of biofertilizers based on biodegradable compounds as an alternative to chemical fertilizers, which is low cost and very effective without harming humans and the environment

Biochemical, ameliorative and cytotoxic effects of newly synthesized curcumin microemulsions: Evidence from in vitro and in vivo studies

Curcumin is known to exhibit antioxidant and tissue-healing properties and has recently attracted the attention of the biomedical community for potential use in advanced therapies. This work reports the formulation and characterization of oil-in-water F127 microemulsions to enhance the bioavailability of curcumin Microemulsions showed a high encapsulation efficiency and prolonged release. To investigate the interactions of curcumin with one unit of the polymeric chain of surfactant F127, ethyl butyrate, and sodium octanoate, as well as the interaction between ethyl butyrate and one unit of the F127 polymer chain, the Density Functional Theory (DFT) calculations at the M06-2X level of theory, were performed in water solution. The MTT assay was used to assess the cytotoxicity of free and encapsulated curcumin on non-malignant and malignant cell lines. Combination effects were calculated according to Chou-Talalay’s principles. Results of in vitro studies indicated that MCF7 and HepG2 cells were more sensitive to curcumin microemulsions. Moreover, a synergistic relationship was observed between curcumin microemulsions and cisplatin in all affected fractions of MCF7 and HepG2 cells (CI < 0.9). For in vivo investigation, thioacetamide-intoxicated rats received thioacetamide (100 mg/kg Sc) followed by curcumin microemulsions (30 mg/kg Ip). Thioacetamideintoxicated rats showed elevated serum liver enzymes, blood urea nitrogen (BUN), and creatinine levels, and a significant reduction in liver superoxide dismutase (SOD) and catalase (CAT) activities (p < 0.05). Curcumin microemulsions reduced liver enzymes and serum creatinine and increased the activity of antioxidant enzymes in thioacetamide-treated rats in comparison to the untreated thioacetamide-intoxicated group. Histopathological investigations confirmed the biochemical findings. Overall, the current results showed the desirable hepatoprotective, nephroprotective, and anti-cancer effects of curcumin microemulsions