Ultrasonic-assisted synthesis of CaCu3Ti4O12/reduced graphene oxide composites for enhanced photocatalytic degradation of pharmaceutical products: Ibuprofen and Ciprofloxacin.

The objective of this research is to create a highly effective approach for eliminating pollutants from the environment through the process of photocatalytic degradation. The study centers around the production of composites consisting of CaCu3Ti4O12 (CCTO) and reduced graphene oxide (rGO) using an ultrasonic-assisted method, with a focus on their capacity to degrade ibuprofen (IBF) and ciprofloxacin (CIP) via photodegradation. The impact of rGO on the structure, morphology, and optical properties of CCTO was inspected using XRD, FTIR, Raman, FESEM, XPS, BET, and UV-Vis. Morphology characterization showed that rGO particles were dispersed within the CCTO matrix without any specific chemical interaction between CCTO and C in the rGO. The BET analysis revealed that with increasing the amount of rGO in the composite, the specific surface area significantly increased compared to the CCTO standalone. Besides, increasing rGO resulted in a reduction in the optical bandgap energy to around 2.09 eV, makes it highly promising photocatalyst for environmental applications. The photodegradation of IBF and CIP was monitored using visible light irradiation. The results revealed that both components were degraded above 97% after 60 min. The photocatalyst showed an excellent reusability performance with a slight decrease after five runs to 93% photodegradation efficiency.

CA19-9 and CEA biosensors in pancreatic cancer.

Cancer is a complex pathophysiological condition causing millions of deaths each year. Early diagnosis is essential especially for pancreatic cancer. Existing diagnostic tools rely on circulating biomarkers such as Carbohydrate Antigen 19-9 (CA19-9) and Carcinoembryonic Antigen (CEA). Unfortunately, these markers are nonspecific and may be increased in a variety of disorders. Accordingly, diagnosis of pancreatic cancer generally involves more invasive approaches such as biopsy as well as imaging studies. Recent advances in biosensor technology have allowed the development of precise diagnostic tools having enhanced analytical sensitivity and specificity. Herein we examine these advances in the detection of cancer in general and in pancreatic cancer specifically. Furthermore, we highlight novel technologies in the measurement of CA19-9 and CEA and explore their future application in the early detection of pancreatic cancer.

Use of Saponinosomes from Ziziphus spina-christi as Anticancer Drug Carriers.

Saponins are plant glycosides with different structures and biological activities, such as anticancer effects. Ziziphus spina-christi is a plant rich in saponin, and this compound is used to treat malignant melanoma in the present study. Nanophytosomes can be used as an advantageous nanodrug delivery system for plant extracts. The aim of this work is to use the saponin-rich fraction (SRF) from Z. spina-christi and prepare SRF-loaded nanophytosomes (saponinosomes) and observe the in vitro and in vivo effects of these carriers. First, the SRF was obtained from Z. spina-christi by a solvent-solvent fractionation method. Then, Fourier transform infrared (FTIR) analyses were performed to confirm the presence of saponins in the extracted material. Subsequently, the saponinosomes were prepared by the solvent injection method (ether injection method) using a 1:1:1 ratio of lecithin/cholesterol/SRF in the mixture. Characterization of the prepared saponinosomes was performed by FTIR, dynamic light scattering (DLS), field-emission scanning electron microscopy (FE-SEM), and atomic force microscopy (AFM) analyses. In addition, a UV-vis spectrophotometer was used to determine the entrapment efficiency (EE) and in vitro release of the SRF. Finally, cell cytotoxicity of the different formulations was evaluated using a 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl tetrazolium bromide (MTT) assay on both mouse melanoma cells (B16F10) and fibroblasts (L929). Using DLS, AFM, and FE-SEM analyses, the particle size was determined to be 58 ± 6 nm with a zeta potential of -32 ± 2 mV. The calculated EE was 85 ± 3%. The results of the in vitro release profile showed that 68.2% of the SRF was released from the saponinosome after 48 h. The results of the MTT assay showed that the SRF and saponinosomes have high toxicity on B16F10 melanoma cells, but saponinosomes showed a significant decrease in cytotoxicity on L929 fibroblast cells compared with that of the SRF. Our results indicate that the SRF from Z. spina-christi has anticancer activity, and the saponinosomes prepared in this work can control tumor growth, improve therapeutic efficacy, and reduce the side effects of saponins.

10-hydroxy-2-decenoic acid a bio-immunomodulator in tissue engineering; generates tolerogenic dendritic cells by blocking the toll-like receptor4.

Dendritic cells (DCs), in response to the biomaterials, utilize toll-like receptors (TLRs) to become mature or tolerogenic through TLRs-dependent signaling pathways, especially TLR4. Regarding the physicochemical properties of biomaterials, some of such signaling pathways are activated. Unsaturated fatty acids have been explored as an antagonist for TLRs and lead to the tolerogenic phenotype of DCs. Here we showed that, although cultured DCs on both chitosan and Alginate-polyethyleneimine (Alg-PEI) films became fully mature, 10-hydroxy-2-decanoic acid (10-HDA), an unsaturated fatty acid found in royal jelly, led to the tolerogenic immunophenotype of DCs on both films. The cultured cells on the films possessed iDCs-like morphology in the presence of 10-HDA. Moreover, 10-HDA expressed lower levels of CD80, CD83, CD86, and HLA-DR, a higher level of IL-10, and lower level of IL-12 in the cultured DCs on both films. Furthermore, HEK293T cells expressing only TLR4 (HEK-TLR4 cells) were co-cultured with LPS, a specific agonist for TLR4, and 10-HDA. The 10-HDA significantly reduced the expression of tumor necrosis factor-a (TNF-α) in the HEK-TLR4 cells compared to treated only with LPS. These findings indicate that the 10-HDA acts as an antagonist of TLR4; therefore, potentially can be used in autoimmune diseases and preventing the rejection of biomaterials implantation and allograft transplantation.

A Novel Non-enzymatic Biosensor Based on Ti-Metallic Glass Thin Film: The Blood Glucose Oxidation Approach.

BACKGROUND: Material selection is a key issue for the fabrication of non-enzymatic electrode in glucose biosensors. Metallic glass (MG) as an advanced innovative material can provides many basic structural requirements of electrodes. A novel non-enzymatic biosensor based on Ti57Cu28{Zr0.95-Hf0.05}XSi15-X MG (Ti-MG) thin film was introduced for glucose oxidation. METHODS: The Ti-MG thin film was deposited on the carbon substrate of screen-printed carbon electrode (SPCE), and the Ti-MG modified SPCE was fabricated as Ti-MG/SPCE. The morphology and structure of the Ti-MG thin film were characterized by field emission scanning electron microscope and X-ray diffraction. Electrochemical evaluations were studied by electrochemical impedance spectroscopy and cyclic voltammetry. RESULTS: The Ti-MG was sputtered on the carbon substrate in the form of a porous spongy thin film with 285 nm thickness and nanoparticles with average diameter size of 110 nm. The Ti-MG/SPCE showed low charge transfer resistance to the electron transfer and high electrocatalytic activity toward the oxidation of glucose in PBS (pH = 7.4) solution. This biosensor exhibited good analytical performance with a linear range from 2 to 8 mM glucose and sensitivity of 0.017 µA mM-1. CONCLUSION: The experimental results indicate that Ti-MG thin film has a high ability to electron transfer and glucose oxidation for the development of non-enzymatic glucose biosensors.

Dendritic Cells as Targets for Biomaterial-Based Immunomodulation.

Various subtypes of immunocytes react against implanted biomaterials to eliminate the foreign body object from the host's body. Among these cells, dendritic cells (DCs) play a key role in early immune response, later engaging lymphocytes through antigens presentation. Due to their capability to induce tolerogenic or immunogenic responses, DCs have been considered as key therapeutic targets for immunomodulatory products. For instance, tolerogenic DCs are applied in the treatment of autoimmune diseases, rejection of allograft transplantation, and implanted biomaterial. Due to the emerging importance of DCs in immunomodulatory biomaterials, this Review summarizes DCs' responses-such as adhesion, migration, and maturation-to biomaterials. We also review some examples of key molecules and their applications in DCs' immunoengineering. These evaluations would pave the way for designing advanced biomaterials and nanomaterials to modulate the immune system, applicable in tissue engineering, transplantation, and drug delivery technologies.

Preparation and characterization of MnS2/chitosan­sodium alginate and calcium alginate nanocomposites for degradation of analgesic drug: Photocorrosion, mechanical, antimicrobial and antioxidant properties studies.

MnS2, MnS2/Chitosan­sodium Alginate (MnS2/CS-NaAlg) and MnS2/Chitosan-Calcium Alginate (MnS2/CS-CaAlg) nanocomposites were prepared via the chemical procedure. The characterization was performed by various instruments such as energy dispersive X-ray spectrometer (EDX), scanning electron microscopy (SEM), X-ray diffraction (XRD) elemental map analysis, Fourier transform infrared spectrometry (FT-IR), Brunauer-Emmett-Teller (BET) surface area measurements, UV-Vis absorption spectra and X-ray absorption spectroscopy. The mean crystallite sizes of MnS2, MnS2/CS-NaAlg and MnS2/CS-CaAlg are 60.12, 71.25 and 74.54 nm, respectively. From Kubelka-Munk equation, the energy band gaps of MnS2, MnS2/CS-NaAlg and MnS2/CS-CaAlg are estimated to be 2.83, 2.71 and 2.41 eV, respectively. The investigation of photocatalysis properties was performed by degradation of tramadol under UV light illumination. The optimum of experimental variables such as pH and time on photo-degradation were found 3 and 60 min, respectively. The results show that the efficiency photocatalysis of MnS2/CS-NaAlg and MnS2/CS-CaAlg nanocomposites under was higher than MnS2. The antibacterial and fungicidal property of MnS2/CS-NaAlg and MnS2/CS-CaAlg nanocomposites was investigated and demonstrates good efficiency in antimicrobial efficiency compared to MnS2. The MnS2, MnS2/CS-NaAlg and MnS2/CS-CaAlg have been shown excellent mechanical and antioxidant properties.

Prediction of storage modulus in solid-like poly (lactic acid)/poly (ethylene oxide)/carbon nanotubes nanocomposites assuming the contributions of nanoparticles and interphase regions in the networks.

In this paper, Kolarik model for tensile modulus of co-continuous blends is developed to predict the storage modulus of poly (lactic acid) (PLA)/poly (ethylene oxide) (PEO)/carbon nanotubes (CNT) nanocomposites at low frequencies (solid-like region). The storage moduli of prepared samples are obtained by frequency sweep test and Kolarik model is expanded assuming the characteristics of interphase regions and CNT networks. The developed model takes into account the percolation threshold, the percentage of networked CNT and the volume fraction of interphase regions in the networks. The calculations of developed model are compared to the experimental data and the significances of main parameters on the storage modulus are justified. The calculations successfully agree with the experimental data at different PLA and CNT concentrations. The addition of CNT thickens and strengthens the interphase regions in the samples, but the different concentrations of PLA differently affect the properties of interphase regions. A thick and strong interphase enhances the storage modulus of nanocomposites. The high fraction of networked CNT and the significant modulus of nanoparticles considerably promote the storage modulus, but only small networks cause poor storage modulus for nanocomposites.

On the prediction of critical micelle concentration for sugar-based non-ionic surfactants.

Micellization phenomenon occurs in natural and technical processes, necessitating the need to develop predictive models capable of predicting self-assembly behavior of surfactants. A least squares support vector machine (LSSVM) based quantitative structure property relationships (QSPR) model is developed in order to predict critical micelle concentration (CMC) for sugar-based surfactants. Model development is based on training and validating a predictive LSSVM strategy using a comprehensive data base consisting of 83 sugar-based surfactants. Model's reliability and robustness has been evaluated using different visual and statistical parameters, revealing its great predictive capabilities. Results are also compared to previously reported best multi-linear regression (BMLR) based QSPR and group contribution based models, showing better performance of the proposed LSSVM-based QSPR model regarding lower RMSE value of 0.023 compared to the group contribution based and the best results from BMLR-based QSPR.

Estimation of the tensile modulus of polymer carbon nanotube nanocomposites containing filler networks and interphase regions by development of the Kolarik model.

In this paper, the Kolarik model for the tensile modulus of co-continuous blends based on cross-orthogonal skeleton structures is simplified and developed for polymer/carbon nanotube (CNT) nanocomposites assuming continuous CNT networks in the polymer matrix and the reinforcing and percolating efficiencies of the interphase. For this purpose, the Ouali model for the modulus of nanocomposites above the percolation threshold is linked with the Kolarik model and the interphase percolation is considered with the excluded volume of the nanoparticles. In addition, the simplified Kolarik model is developed with the interphase as a new phase surrounding the nanofiller. A good agreement between the experimental data and the predictions is observed in the samples containing interphases and filler networks, while the developed model cannot estimate the modulus in the absence of interphases and network structures. The developed model demonstrates the effects of all the parameters on the modulus. The interphase parameters more significantly affect the modulus compared to the concentration and modulus of the filler, demonstrating the importance of the interphase properties.

Finite element analysis of post dental implant fixation in drilled mandible sites.

BACKGROUND: Implant loosening may occur after dental implant placement as a result of the mechanical conditions created around the implant. In this research, the effect of bone drilling conditions on the magnitude of stress created in newly-formed bone around the implant, after placement, was investigated using FEA analysis. METHOD: The simulations performed in this study were based on the three-dimensional (3D) shape of the created cavities, extracted from the drilled cortical bone of the jaws. With this aim, a dental implant model was placed in the jaw and a shell of the 3D bone cavity remained as a newly-formed cortical bone after implant placement. Then, a load was exerted on the implant model and the value of stress created on the newly-formed bone was obtained. Overall, eight combined models were used in all the eight drilling and loading simulations. The examined variables were rotational speed of drill bit, its feed rate and head angle. Also, an animal test was performed to investigate the accuracy of the simulation results. RESULTS: The results of this study showed that the amount of principal stress was the least (16.7MPa) for a newly-formed cortical bone whose cavity was created under drilling condition at the same head angle and feed rate of the drill bit with a rotational speed of 400rpm. The same results were obtained for the head angle and feed rate of a drill bit of 70° and 1.5mm/s, respectively. CONCLUSIONS: Drilling conditions have effect on the stress created in a newly-formed cortical bone after dental implant loading.