Abstract
Systemic chemotherapy remains the backbone of many cancer treatments. Due to its untargeted nature and the severe side effects it can cause, numerous nanomedicine approaches have been ...developed to overcome these issues. However, targeted delivery of therapeutics remains challenging. Engineering microrobots is increasingly receiving attention in this regard. Their functionalities, particularly their motility, allow microrobots to penetrate tissues and reach cancers more efficiently. Here, we highlight how different microrobots, ranging from tailor-made motile bacteria and tiny bubble-propelled microengines to hybrid spermbots, can be engineered to integrate sophisticated features optimised for precision-targeting of a wide range of cancers. Towards this, we highlight the importance of integrating clinicians, the public and cancer patients early on in the development of these novel technologies.
In this study, we present a combined density functional theory and many-body perturbation theory study on the electronic and optical properties of TiO2 brookite as well as the tetragonal phases ...rutile and anatase. The electronic structure and linear optical response have been calculated from the Kohn-Sham band structure applying (semi)local as well as nonlocal screened hybrid exchange-correlation density functionals. Single-particle excitations are treated within the GW approximation for independent quasiparticles. For optical response calculations, two-particle excitations have been included by solving the Bethe-Salpeter equation for Coulomb correlated electron-hole pairs. On this methodological basis, gap data and optical spectra for the three major phases of TiO2 are provided. The common characteristics of brookite with the rutile and anatase phases, which have been discussed more comprehensively in the literature, are highlighted. Furthermore, the comparison of the present calculations with measured optical response data of rutile indicate that discrepancies discussed in numerous earlier studies are due to the measurements rather than related to an insufficient theoretical description.
Cytokine‐induced killer (CIK) cells represent an exceptional T‐cell population uniting a T cell and natural killer cell‐like phenotype in their terminally differentiated CD3+CD56+ subset, which ...features non‐MHC‐restricted tumor‐killing activity. CIK cells have provided encouraging results in initial clinical studies and revealed synergistic antitumor effects when combined with standard therapeutic procedures. We established the international registry on CIK cells (IRCC) to collect and evaluate clinical trials for the treatment of cancer patients in 2010. Moreover, our registry set new standards on the reporting of results from clinical trials using CIK cells. In the present update, a total of 106 clinical trials including 10,225 patients were enrolled in IRCC, of which 4,889 patients in over 30 distinct tumor entities were treated with CIK cells alone or in combination with conventional or novel therapies. Significantly improved median progression‐free survival and overall survival were shown in 27 trials, and 9 trials reported a significantly increased 5‐year survival rate. Mild adverse effects and graft‐versus‐host diseases were also observed in the studies. Recently, more efforts have been put into the improvement of antitumoral efficacy by CIK cells including the administration of immune checkpoint inhibitors and modification with chimeric antigen receptorc. The minimal toxicity and multiple improvements on their tumor‐killing activity both make CIK cells a favorable therapeutic tool in the clinical practice of cancer immunotherapy.
Cytokine‐induced killer (CIK) cells featuring non‐MHC‐restricted tumor‐killing activity have provided encouraging results in clinical studies. Here, we update the clinical data including a total of 106 trials enrolled in the international registry on CIK cells (IRCC) established in 2010. The recent multiple improvements both on antitumoral efficacy and toxicity make CIK cells an important therapeutic approach in clinical practice of cancer immunotherapy.
A sperm-driven micromotor is presented as a targeted drug delivery system, which is appealing to potentially treat diseases in the female reproductive tract. This system is demonstrated to be an ...efficient drug delivery vehicle by first loading a motile sperm cell with an anticancer drug (doxorubicin hydrochloride), guiding it magnetically, to an in vitro cultured tumor spheroid, and finally freeing the sperm cell to deliver the drug locally. The sperm release mechanism is designed to liberate the sperm when the biohybrid micromotor hits the tumor walls, allowing it to swim into the tumor and deliver the drug through the sperm–cancer cell membrane fusion. In our experiments, the sperm cells exhibited a high drug encapsulation capability and drug carrying stability, conveniently minimizing toxic side effects and unwanted drug accumulation in healthy tissues. Overall, sperm cells are excellent candidates to operate in physiological environments, as they neither express pathogenic proteins nor proliferate to form undesirable colonies, unlike other cells or microorganisms. This sperm-hybrid micromotor is a biocompatible platform with potential application in gynecological healthcare, treating or detecting cancer or other diseases in the female reproductive system.
Micromotors are recognized as promising candidates for untethered micromanipulation and targeted cargo delivery in complex biological environments. However, their feasibility in the circulatory ...system has been limited due to the low thrust force exhibited by many of the reported synthetic micromotors, which is not sufficient to overcome the high flow and complex composition of blood. Here we present a hybrid sperm micromotor that can actively swim against flowing blood (continuous and pulsatile) and perform the function of heparin cargo delivery. In this biohybrid system, the sperm flagellum provides a high propulsion force while the synthetic microstructure serves for magnetic guidance and cargo transport. Moreover, single sperm micromotors can assemble into a train-like carrier after magnetization, allowing the transport of multiple sperm or medical cargoes to the area of interest, serving as potential anticoagulant agents to treat blood clots or other diseases in the circulatory system.
Origami MEMS and NEMS Rogers, John; Huang, Yonggang; Schmidt, Oliver G. ...
MRS bulletin,
02/2016, Letnik:
41, Številka:
2
Journal Article
Recenzirano
Odprti dostop
In a manner reminiscent of macroscale bending and folding techniques such as origami, the out-of-plane assembly of lithographically micro- and nanopatterned thin films, can be used to fabricate ...three-dimensional (3D) micro- and nanostructured devices. These 3D devices, including microelectronic circuits, sensors, antennas, metamaterials, robotic, and biomimetic constructs, enable new functionalities and are challenging to fabricate by other methods. In this article, we summarize important features of this set of techniques and the devices assembled thereof, with a focus on functional constructs that have been formed by bending, folding, or buckling. At small size scales, manipulation using manual or even wired probes face daunting practical challenges in terms of cost, scalability, and high-throughput manufacturability; hence we emphasize techniques that manipulate strain in thin films so that they can spontaneously assemble into programmed 3D geometries without the need for any wires or probes.
We present artificially motorized sperm cellsa novel type of hybrid micromotor, where customized microhelices serve as motors for transporting sperm cells with motion deficiencies to help them carry ...out their natural function. Our results indicate that metal-coated polymer microhelices are suitable for this task due to potent, controllable, and nonharmful 3D motion behavior. We manage to capture, transport, and release single immotile live sperm cells in fluidic channels that allow mimicking physiological conditions. Important steps toward fertilization are addressed by employing proper means of sperm selection and oocyte culturing. Despite the fact that there still remain some challenges on the way to achieve successful fertilization with artificially motorized sperms, we believe that the potential of this novel approach toward assisted reproduction can be already put into perspective with the present work.
Spintronics is a topic that has raised a lot of interest during the past years. The transport and manipulation of spin polarized electrons or holes in semiconductors offers a huge potential for novel ...devices that combine non-volatile information storage with high processing speed at low power, and which may even be useful for quantum computation. However, one major ingredient that has been missing for a long time is the transfer of spin polarized carriers from a magnetic contact into a non-magnetic semiconductor. Highly efficient electrical spin injection was realized for the first time in 1999 (Fiederling R et al Nature 402 787). Since then, several experiments have successfully demonstrated spin injection into semiconductors and additional concepts for spin filters and spin aligners have been proposed. Some of the experiments also yielded high spin injection efficiencies; however, in other experiments no unambiguous results could be obtained, and for many of the proposed concepts even a proof of principle is still missing. In this review, the suitability of different contact types for spin injection will be discussed together with a review of possible detection mechanisms that can be used in the experiment. By using a simple model based on load-lines we will show that for most spin aligners a first estimate of the injection efficiency can easily be obtained without complicated calculations.
Flexible thermoresponsive polymeric microjets are formed by the self‐folding of polymeric layers containing a thin Pt film used as catalyst for self‐propulsion in solutions containing hydrogen ...peroxide. The flexible microjets can reversibly fold and unfold in an accurate manner by applying changes in temperature to the solution in which they are immersed. This effect allows microjets to rapidly start and stop multiple times by controlling the radius of curvature of the microjet. This work opens many possibilities in the field of artificial nanodevices, for fundamental studies on self‐propulsion at the microscale, and also for biorelated applications.
Micro jet boating: Flexible thermoresponsive polymer microjets can be fabricated. These self‐propelled microjets can reversibly fold and unfold in an accurate manner by applying changes in temperature to the solution in which they are immersed. This effect allows them to start and stop multiple times by controlling the radius of curvature of the microtube.
Carbon–carbon bond formation is the key reaction for organic synthesis to construct the carbon framework of organic molecules. The review gives a selection of biocatalytic C–C-bond-forming reactions ...which have been investigated during the last 5 years and which have already been proven to be applicable for organic synthesis. In most cases, the reactions lead to products functionalized at the site of C–C-bond formation (e.g., α-hydroxy ketones, aminoalcohols, diols, 1,4-diketones, etc.) or allow to decorate aromatic and heteroaromatic molecules. Furthermore, examples for cyclization of (non)natural precursors leading to saturated carbocycles are given as well as the stereoselective cyclopropanation of olefins affording cyclopropanes. Although many tools are already available, recent research also makes it clear that nature provides an even broader set of enzymes to perform specific C–C coupling reactions. The possibilities are without limit; however, a big library of variants for different types of reactions is required to have the specific enzyme for a desired specific (stereoselective) reaction at hand.
PDF
