Search

The accumulation of microplastics in the environment, particularly due to the significant contribution of synthetic clothing washing water, leads to a need for developing source-based retention solutions. The project's objective is to assess the capability of washing machine filters to capture microfibers from domestic wastewater under real laundry conditions. This involves developing a protocol for quantifying microfibers tailored to washing machine lint samples, estimating the potential microfiber capture by washing machine filters, and evaluating the social acceptability of using such filters in households. Volunteers were recruited and they used their washing machines normally, collecting lint in the filter over a 6-month period and documenting information for each load. Various reagents were tested using plastic controls and lint samples to select the most efficient one for removing organic matter without affecting microplastics. Microscopic visual alterations, chemical signatures via FTIR, and the efficacy of the digestion protocol were assessed through mass balance and visual counting. After discarding digestion protocols affecting plastic integrity, those ensuring the most efficient mass loss of organic matter were identified as H2O2 30 % for 5 days at room temperature (RT), NaOCl 3 % for 24 h at RT, and H2O2 30 % at 40 °C for 24 h. Polyester, acrylic, and polyamide controls were tested with NaOCl 3 % for 24 h and H2O2 30 % for 5 days, showing no changes in SEM images. The FTIR successfully recognized the chemical signature. More significant alterations on positive samples (cotton and cellulose) were observed after NaOCl exposure. The mean mass of microfibers remaining after digestion was estimated at 4.62 mg per liter of washing water or 61 mg/kg of washed garment. The survey revealed that 67.8 % of volunteer participants found the filter installation challenging, and 21.4 % had to hire a plumber, highlighting potential challenges associated with implementing washing machine filters on a large scale.

This study examines the development of composite bacterial cellulose (BC) sheets with antimicrobial properties for potential application in face masks. Branched polyethylenimine (PEI) is employed as the antimicrobial agent, effective against both gram-positive and gram-negative bacteria. Various concentrations of PEI are crosslinked into BC via epichlorohydrin under moderate conditions. The thermal and morphological properties of dried BC-PEI samples are comprehensively characterized. Results reveal that introducing PEI via crosslinking minimally impacts the thermal stability of BC, without any discernible physical disruption. Nevertheless, BC-PEI matrices present lower water evaporation enthalpies than BC, based on dynamic scanning calorimetry, caused by alteration of hydrogen bonding interactions (amine groups versus hydroxyl groups). Moreover, dried BC-PEI samples exhibit an improved efficacy against gram-positive bacteria as compared to gram-negative bacteria; S. aureus and P. aeruginosa, respectively. Indeed, a 2.5% (wt/v% of Milli-Q water) PEI concentration completely inhibits the growth of S. aureus after 6 h, while a 7.5% PEI concentration achieves similar effects on P. aeruginosa. Despite the notable antibacterial efficacy of BC-PEI matrices, their antiviral efficacy is less pronounced. This difference in antibacterial and antiviral efficacies could be attributed to variations in microorganism characteristics, mechanisms of action, and structures of PEI.

This study aimed to fabricate and characterize a novel colorimetric indicator designed to detect ammonia (NH3) and monitor meat freshness. The sensing platform was constructed using electrospun nanofibers made from polylactic acid (PLA), which were then impregnated with anthocyanins as a natural pH-sensitive dye, extracted from red cabbage. This research involved investigating the relationship between the various concentrations of anthocyanins and the colorimetric platform’s efficiency when exposed to ammonia vapor. Scanning electron microscope (SEM) results were used to examine the morphology and structure of the nanofiber mats before and after the dip-coating process. The study also delved into the selectivity of the indicator when exposed to various volatile organic compounds (VOCs) and their stability under extreme humidity levels. Furthermore, the platform’s sensitivity was evaluated as it encountered ammonia (NH3) in concentrations ranging from 1 to 100 ppm, with varying dye concentrations. The developed indicator demonstrated an exceptional detection limit of 1 ppm of MH3 within just 30 min, making it highly sensitive to subtle changes in gas concentration. The indicator proved effective in assessing meat freshness by detecting spoilage levels in beef over time. It reliably identified spoilage after 10 h and 7 days, corresponding to bacterial growth thresholds (107 CFU/mL), both at room temperature and in refrigerated environments, respectively. With its simple visual detection mechanism, the platform offered a straightforward and user-friendly solution for consumers and industry professionals alike to monitor packaged beef freshness, enhancing food safety and quality assurance.

Abstract In this work, four different organomontmorillonites (OMMts): Nanomer[R] I.30E, Dellites[R] 43B and 67G and Nanolin[R] DK2 were selected to prepare OMMt-poly (lactic acid) (PLA) nanocomposites blown films, using a [...]

Polylactic acid (PLA) has shown two different crystalline structures, namely α and α′ when cooled down from the melt state. However, α-PLA has shown significant improvement in the barrier and mechanical properties of PLA. Although the effect of some nucleating agents on phase transformation of the PLA has been determined in the past, this is the first attempt, the effect of the starch nanocrystals on the formation of polymorphic crystal structure of PLA was evaluated. In this framework, the effect of lactic acid grafted starch nanocrystals (SNCs-g-LA) concentrations on the phase transition, and crystallization behavior of PLA/SNCs-g-LA nanocomposites at different isothermal crystallization temperatures (Tc) were studied. The results indicate that SNCs-g-LA nanoparticles promote the degree of crystalline transition to yield the highly crystalline ordered α-PLA. Further, the half-time crystallization (t1/2) of PLA composites was calculated by the Avrami equation. The t1/2 of PLA was minimum by adding 5 wt% SNCs-g-LA nanoparticles, and it decreased from 10.4 to 3.9 min. The growth rate of the spherulite morphology of PLA composites showed a significant improvement in the crystalline structure of PLA/SNCs-g-LA (5 wt%) nanocomposites as well. Finally, small angle X-ray scatting (SAXS) analysis showed that the inclusion of 5 wt% grafted SNCs resulted in the increment of the long period (Lac) as well as crystal layer thickness (Lc).

This study aimed to fabricate and characterize a novel colorimetric indicator designed to detect ammonia (NH3) and monitor meat freshness. The sensing platform was constructed using electrospun nanofibers made from polylactic acid (PLA), which were then impregnated with anthocyanins as a natural pH-sensitive dye, extracted from red cabbage. This research involved investigating the relationship between the various concentrations of anthocyanins and the colorimetric platform's efficiency when exposed to ammonia vapor. Scanning electron microscope (SEM) results were used to examine the morphology and structure of the nanofiber mats before and after the dip-coating process. The study also delved into the selectivity of the indicator when exposed to various volatile organic compounds (VOCs) and their stability under extreme humidity levels. Furthermore, the platform's sensitivity was evaluated as it encountered ammonia (NH3) in concentrations ranging from 1 to 100 ppm, with varying dye concentrations. The developed indicator demonstrated an exceptional detection limit of 1 ppm of MH3 within just 30 min, making it highly sensitive to subtle changes in gas concentration. The indicator proved effective in assessing meat freshness by detecting spoilage levels in beef over time. It reliably identified spoilage after 10 h and 7 days, corresponding to bacterial growth thresholds (107 CFU/mL), both at room temperature and in refrigerated environments, respectively. With its simple visual detection mechanism, the platform offered a straightforward and user-friendly solution for consumers and industry professionals alike to monitor packaged beef freshness, enhancing food safety and quality assurance. [ABSTRACT FROM AUTHOR]

Bone is a frequent site of tumor metastasis. The bone–tumor microenvironment is heterogeneous and complex in nature. Such complexity is compounded by relations between metastatic and bone cells influencing their sensitivity/resistance to chemotherapeutics. Standard chemotherapeutics may not show efficacy for every patient, and new therapeutics are slow to emerge, owing to the limitations of existing 2D/3D models. We previously developed a 3D interface model for personalized therapeutic screening, consisting of an electrospun poly lactic acid mesh activated with plasma species and seeded with stromal cells. Tumor cells embedded in an alginate-gelatin hydrogel are overlaid to create a physiologic 3D interface. Here, we applied our 3D model as a migration assay tool to verify the migratory behavior of different patient-derived bone metastasized cells. We assessed the impact of two different chemotherapeutics, Doxorubicin and Cisplatin, on migration of patient cells and their immortalized cell line counterparts. We observed different migratory behaviors and cellular metabolic activities blocked with both Doxorubicin and Cisplatin treatment; however, higher efficiency or lower IC50 was observed with Doxorubicin. Gene expression analysis of MDA-MB231 that migrated through our 3D hybrid model verified epithelial–mesenchymal transition through increased expression of mesenchymal markers involved in the metastasis process. Our findings indicate that we can model tumor migration in vivo, in line with different cell characteristics and it may be a suitable drug screening tool for personalized medicine approaches in metastatic cancer treatment.

The present work seeks to determine the impact of weight percentage (wt%) of grafted starch nanocrystals (g-SNCs) on the oxygen and water vapour permeability of poly (lactic acid), PLA. Changes in the oxygen and water vapour permeability of PLA due to changes in PLA’s crystalline structures and lamellar thickness were quantified. To this end, 3, 5, and 7 wt% of g-SNC nanoparticles were blended with PLA using the solvent casting method in order to study impact of g-SNC nanoparticles on crystallization behaviour, long spacing period, melting behavior, and oxygen and water barrier properties of PLA nanocomposites. This was achieved by wide-angle X-ray diffraction (WAXD), small-angle X-ray diffraction (SAXD), differential scanning calorimetry (DSC), and oxygen and water vapour permeability machine. The results of the WAXD and SAXD analysis show that the addition of 5 wt% g-SNC in PLA induces α crystal structure at a lower crystallization time, while it significantly increases the α crystal thickness of PLA, in comparison to neat PLA. However, when g-SNC concentrations were altered (i.e., 3 or 7 wt%), the crystallization time was found to increase due to the thermodynamic barrier of crystallization. Finally, the oxygen and water vapour permeability of PLA/SNC-g-LA (5 wt%) nanocomposite film were found to be reduced by ∼70% and ~50%, respectively, when compared to the neat PLA film. This can lead to the development of PLA nanocomposites with high potential for applications in food packaging.

Spheroids are recognized for resembling the important characteristics of natural tumors in cancer research. However, the lack of controllability of the spheroid size, form, and density in conventional spheroid culture methods reduces the reproducibility and precision of bioassay results and the assessment of drug-dose responses in spheroids. Nonetheless, the accurate prediction of cellular responses to drug compounds is crucial for developing new efficient therapeutic agents and optimizing existing therapeutic strategies for personalized medicine. We developed a surface-optimized PDMS microfluidic biochip to produce uniform and homogenous multicellular spheroids in a reproducible manner. This platform is surface optimized with 10% bovine serum albumin (BSA) to provide cell-repellent properties. Therefore, weak cell-surface interactions lead to the promotion of cell self-aggregations and the production of compact and uniform spheroids. We used a lung cancer cell line (A549), a co-culture model of lung cancer cells (A549) with (primary human osteoblasts, and patient-derived spine metastases cells (BML, bone metastasis secondary to lung). We observed that the behavior of cells cultured in three-dimensional (3D) spheroids within this biochip platform more closely reflects in vivo-like cellular responses to a chemotherapeutic drug, Doxorubicin, rather than on 24-well plates (two-dimensional (2D) model). It was also observed that the co-culture and patient-derived spheroids exhibited resistance to anti-cancer drugs more than the mono-culture spheroids. The repeatability of drug test results in this optimized platform is the hallmark of the reproducibility of uniform spheroids on a chip. This surface-optimized biochip can be a reliable platform to generate homogenous and uniform spheroids to study and monitor the tumor microenvironment and for drug screening.

Spheroids have become an essential tool in preclinical cancer research. The uniformity of spheroids is a critical parameter in drug test results. Spheroids form by self-assembly of cells. Hence, the control of homogeneity of spheroids in terms of size, shape, and density is challenging. We developed surface-optimized polydimethylsiloxane (PDMS) biochip platforms for uniform spheroid formation on-chip. These biochips were surface modified with 10% bovine serum albumin (BSA) to effectively suppress cell adhesion on the PDMS surface. These surface-optimized platforms facilitate cell self-aggregations to produce homogenous non-scaffold-based spheroids. We produced uniform spheroids on these biochips using six different established human cell lines and a co-culture model. Here, we observe that the concentration of the BSA is important in blocking cell adhesion to the PDMS surfaces. Biochips treated with 3% BSA demonstrated cell repellent properties similar to the bare PDMS surfaces. This work highlights the importance of surface modification on spheroid production on PDMS-based microfluidic devices.

Flavonoids such as naringenin, quercetin, and naringin are known to exhibit anticancer properties. In this study, we examined the effects of these flavonoids on cell viability and apoptotic pathways of cancer cells, either singly or in combination with the type 1 ribosome inactivating protein, Balsamin. Treatment with flavonoids (naringenin, quercetin, and naringin) plus Balsamin for 48 h reduced HepG2 and MCF-7 cell viability, increased the activation of caspase-3 and -8, and induced apoptosis through up-regulation of pro-apoptotic genes and down-regulation of anti-apoptotic genes. Out of the three flavonoids tested, the Balsamin-Naringenin and Balsamin-Quercetin combinations appeared to be most effective compared to the Balsamin-Naringin combination. Balsamin combined with flavonoids also activated endoplasmic reticulum (ER)-stress–mediated apoptosis in breast cancer (MCF-7) cells, which was not activated by Balsamin treatment alone. These experimental results showed that Balsamin combined with flavonoids can reduce HepG2 and MCF-7 cells viability and induce apoptosis, which could be considered as a promising therapeutic approach to sensitize cells to Balsamin treatment, thereby improving its efficacy in breast or liver cancer therapy.

أجريت الفلكنة الإشعاعية لمتراكبات من مطاط النتريل بوتاديين (Nitrile Butadiene Rubber) الذي يحتوي نسب مختلفة من الكربون الأسود (Carbon Black) باستخدام أشعة غاما بجرعات تصل إلى (300 KGy). بينت نتائج الدراسة انخفاض نسبة انتباج المتراكبات المطاطية في زيتي الهيدروليك والمحرك مع زيادة الجرعة الإشعاعية وكذلك مع زيادة نسبة التحميل بالكربون الأسود، غير أن هذه النسبة تزداد بشكل بسيط بزيادة درجة حرارة الزيت المدروس. كما بينت نتائج التحليل الحراري للمتراكبات زيادة درجة حرارة التزجج مع زيادة الجرعة الإشعاعية نتيجة للتشابك المستحث إشعاعياً الذي يعمل على تقييد حرية حركة سلاسل المطاط النتريلي. دُرس أيضاً تأثير الجرعة الإشعاعية في مقدار تآكل المتراكبات من خلال قياس حجم الجزء المتآكل من المادة، وتبين أن مقاومة التآكل تزداد بزيادة الجرعة الإشعاعية حتى (150 KGy) ومن ثم تأخذ بالتناقص.