A facile approach for preparation of photoluminescent (PL) carbon dots (CDs) is reported. The three resulting CDs emit bright and stable red, green and blue (RGB) colors of luminescence, under a ...single ultraviolet‐light excitation. Alterations of PL emission of these CDs are tentatively proposed to result from the difference in their particle size and nitrogen content. Interestingly, up‐conversion (UC)PL of these CDs is also observed. Moreover, flexible full‐color emissive PVA films can be achieved through mixing two or three CDs in the appropriate ratios. These CDs also show low cytotoxicity and excellent cellular imaging capability. The facile preparation and unique optical features make these CDs potentially useful in numerous applications such as light‐emitting diodes, full‐color displays, and multiplexed (UC)PL bioimaging.
On the dot: A facile approach to photoluminescent carbon dots (CDs) that can be excited by a single wavelength and demonstrate emission of the three primary colors (red, green, and blue) is reported. The resulting CDs can be potentially used in the fabrication of flexible full‐color emission films and in multicolor cellular imaging.
The bulk of Earth's biological materials consist of few base substances-essentially proteins, polysaccharides, and minerals-that assemble into large varieties of structures. Multifunctionality arises ...naturally from this structural complexity: An example is the combination of rigidity and flexibility in protein-based teeth of the squid sucker ring. Other examples are time-delayed actuation in plant seed pods triggered by environmental signals, such as fire and water, and surface nanostructures that combine light manipulation with mechanical protection or water repellency. Bioinspired engineering transfers some of these structural principles into technically more relevant base materials to obtain new, often unexpected combinations of material properties. Less appreciated is the huge potential of using bioinspired structural complexity to avoid unnecessary chemical diversity, enabling easier recycling and, thus, a more sustainable materials economy.
Three‐dimensional cell culture models, such as spheroids, can be used in the process of the development of new anticancer agents because they are able to closely mimic the main features of human ...solid tumors, namely their structural organization, cellular layered assembling, hypoxia, and nutrient gradients. These properties imprint to the spheroids an anticancer therapeutics resistance profile, which is similar to that displayed by human solid tumors. In this review, an overview of the drug resistance mechanisms observed in 3D tumor spheroids is provided. Furthermore, comparisons between the therapeutics resistance profile exhibited by spheroids, and 2D cell cultures are presented. Finally, examples of the therapeutic approaches that have been developed to surpass the drug resistance mechanisms exhibited by spheroids are described.
Drug resistance phenotype acquired by the cancer cells is still the major cause of the patient’s low survival rates. Spheroids in vitro models represent more closely the characteristics of the human tumors, which prompted its use in the development of new therapeutics. In this review, the structural and functional similarities between spheroids and in vivo human solid tumors are reviewed, highlighting the common drug resistance mechanisms, as well as the therapeutic approaches explored to surpass this resistance.
HIGHLIGHTS
The suitability of 3D cell culture models for drug screening purposes is highlighted.
Spheroids and in vivo human solid tumors structural and functional similarities are emphasized.
The drug resistance mechanisms exhibited by spheroids are described.
Therapeutic approaches used to surpass spheroids’ drug resistance mechanisms are described.
Dispersive liquid-liquid microextraction (DLLME) has become a very popular environmentally benign sample-preparation technique, due to its simplicity, speed of operation and low consumption of ...solvent and reagent. It has attracted much interest from scientists working in separation science, and much improvement has been made since its introduction in 2006.
We describe the combined use of different types of ionic liquid dispersive liquid–liquid microextraction (IL-DLLME) such as META IL-DLLME (magnetic effervescent tablet-assisted ionic liquid dispersive liquid-liquid microextraction), in-situ MR-IL-DLLME (in situ magnetic retrieval ionic liquid dispersive liquid–liquid microextraction), and MIL-DLLME (magnetic ionic liquid-based dispersive liquid–liquid microextraction) methods as well as the green aspects of these techniques. In addition, we discuss practical applications of IL-DLLME to determine organic compounds and metals in a variety of matrices e.g., in water, food, biological samples, cosmetics and other products.
•Combined use of different types of IL-DLLME such as META IL-DLLME, in-situ MR-IL-DLLME and MIL-DLLME methods•Applications to determine organic compounds and metals in a variety of matrices e.g., in water, food, cosmetics etc.•Green aspects of IL-DLLME methods
Shine on you crazy dots: A rapid and high‐output strategy allows the fabrication of polymer‐like carbon dots (CDs) with quantum yields as high as ca. 80 %. This value is the highest reported to date ...for fluorescent carbon‐based materials, and gives promise for their application in multicolor‐patterning and biosensors.
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The unique physical properties of graphene and its composites, combined with the capability of additive manufacturing (AM), to net shape manufacture intricate 3D objects ...layer-by-layer, promise to open up a plethora of new opportunities and challenges. In this review, we provide a comprehensive overview of graphene-based ceramic, metal, and polymer composites, produced by a variety of AM methods. It will be shown that the multifunctional properties and potential capabilities of graphene-based composites can be uniquely exploited by the use of AM technologies, enabling novel applications in fields like biomedicine, energy, sensing and electromagnetic interference (EMI) shielding.
Direct-write 3D printing enables the fabrication of three-dimensional objects via the extrusion from a nozzle. Stimuli responsive materials that shear-thin are well-suited as inks for these 3D ...printing systems. Poly(isopropyl glycidyl ether)-block-poly(ethylene oxide)-block-poly(isopropyl glycidyl ether) ABA triblock copolymers were synthesized using controlled ring-opening polymerization to afford dual stimuli-responsive polymers that respond to both shear forces and temperature. These polymers were demonstrated to form hydrogels in water. The gels were observed to be thermoreversibledriven by the lower critical solution temperature of the poly(isopropyl glycidyl ether) block which helps facilitate loading of the ink into the printer syringe. Rheological studies demonstrated that the gels had a rapid and reversible modulus response to shear stress. Thus, these materials were suitable as inks for direct-write 3D printing, as they were easily extruded during printing and maintained sufficient mechanical integrity which was necessary to support the next printed layer. Printed structures of high aspect ratio pillars and stacked layers were successfully demonstrated. These types of 3D hydrogel structures may ultimately have an impact in the biomedical field for applications such as tissue engineering.
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