The influence of oxygen on various ophthalmological complications is not completely understood and intraocular oxygen measurements are essential for better diagnosis and treatment. A magnetically ...controlled wireless sensor device is proposed for minimally invasive intraocular oxygen concentration measurements. This device will make it possible to make measurements at locations that are currently too invasive for human intervention by integrating a luminescence optical sensor and a magnetic steering system. The sensor works based on quenching of luminescence in the presence of oxygen. A novel iridium phosphorescent complex is designed and synthesized for this system. A frequency-domain lifetime measurement approach is employed because of the intrinsic nature of the lifetime of luminescence. Experimental results of the oxygen sensor together with magnetic and hydrodynamic characterization of the sensor platform are presented to demonstrate the concept. In order to use this sensor for in vivo intraocular applications, the size of the sensor must be reduced, which will require an improved signal-to-noise ratio.
For microassembly tasks uncertainty exists at many levels. Single static sensing configurations are therefore unable to provide feedback with the necessary range and resolution for accomplishing many ...desired tasks. In this paper we present experimental results that investigate the integration of two disparate sensing modalities, force and vision, for sensor-based microassembly. By integrating these sensing modes, we are able to provide feedback in a task-oriented frame of reference over a broad range of motion with an extremely high precision. An optical microscope is used to provide visual feedback down to micron resolutions, while an optical beam deflection technique (based on a modified atomic force microscope) is used to provide nanonewton level force feedback or nanometric level position feedback. Visually servoed motion at speeds of up to 2 mm/s with a repeatability of 0.17 μm are achieved with vision alone. The optical beam deflection sensor complements the visual feedback by providing positional feedback with a repeatability of a few nanometers. Based on the principles of optical beam deflection, this is equivalent to force measurements on the order of a nanonewton. The value of integrating these two disparate sensing modalities is demonstrated during controlled micropart impact experiments. These results demonstrate micropart approach velocities of 80 μm/s with impact forces of 9 nN and final contact forces of 2 nN. Within our microassembly system this level of performance cannot be achieved using either sensing modality alone. This research will aid in the development of complex hybrid MEMS devices in two ways; by enabling the microassembly of more complex MEMS prototypes; and in the development of automatic assembly machines for assembling and packaging future MEMS devices that require increasingly complex assembly strategies.PUBLICATION ABSTRACT
Directed nanoparticle self‐organization and twophoton polymerization are combined to enable three‐dimensional soft‐magnetic actuators with complex shapes and shape‐independent magnetic properties as ...demonstrated by the twisttype microactuators. As discussed by C. Peters and co‐workers on page 5269, generic and facile combination of glycine grafting and subsequent protein immobilization exploits the actuator's increased surface area, providing for a swimming microrobotic platform with enhanced load capacity desirable for future biomedical applications.
Hydrogel-based robotic microdevices are currently investigated for minimally invasive medical procedures. Hydrogels are especially suited to targeted drug delivery applications as they are able to ...carry several times more drug solution than its dry weight. A major drawback of these system is that drug release takes place before reaching the targeted area in the body. We introduce a strategy based on a self-folding bilayer to prevent release during transportation without hindering the drug loading efficiency of the hydrogel. The drug is loaded into the hydrogel matrix at room temperature. When the temperature is increased to body temperature, the hydrogel-matrix collapses and the self-folded bilayer refolds into another tube. In this configuration, we observed a significant reduction in drug leakage with less than 5% drug loss during encapsulation. Finally, we demonstrate that the tube can be manipulated magnetically, which shows its potential use in targeted drug delivery applications.
Digital holography is used to track the three-dimensional position of a magnetic microrobot maneuvered in real time by means of an electromagnetic manipulation system. The method presented is able to ...process holograms at 40 Hz with a position accuracy in the imaging plane and in depth of <inline-formula><tex-math notation="LaTeX">\pm </tex-math></inline-formula>23 and <inline-formula><tex-math notation="LaTeX">\pm</tex-math></inline-formula> 180 <inline-formula><tex-math notation="LaTeX">\mu</tex-math></inline-formula>m, respectively. As this method does not require magnification, microrobots can be tracked in significantly larger working volumes than conventional optical methods. The performance of this tracking method is demonstrated by visually servoing a magnetic bead around a cubic trajectory.
Advancing plant biological research has an important function in the food chain and economic systems. In article number 1800527, Daniel Ahmed and co‐workers present a rotational manipulation method ...using acoustically activated microbubbles to investigate opaque and non‐spherical plant cells. The rotational behavior of the plant cells is characterized in open and closed microchannels for 3D visualization and interaction.
Microassembly systems are a class of representative optomechatronic systems that play a critical role in the fabrication, packaging, and interconnection of hybrid microsystems such as hybrid ...microelectromechanical systems. Optomechatronic integration is essential to the development of microassembly systems due to the basic importance of microscope optics to microassembly. In this paper, the role of microscope optics in microassembly systems is analyzed. The general architecture of microassembly systems is introduced. Unique properties of microscale optomechatronics that differ from macroscale optomechatronics are summarized. These fundamental differences motivate the definition and discussion of microoptomechatronics. Major methodology issues in optomechatronic design of microassembly systems are introduced using examples. A wavelet-based microscopic image segmentation technique is presented to demonstrate the strength of using the unique properties of microoptomechatronics in microscopic image information processing.
Chimeric antibody Miltuximab®, a human IgG1 engineered from the parent antibody MIL-38, is in clinical development for solid tumour therapy. Miltuximab® targets glypican-1 (GPC-1), a cell surface ...protein involved in tumour growth, which is overexpressed in solid tumours, including prostate cancer (PCa). This study investigated the potential of
Zr-labelled Miltuximab® as an imaging agent, and
Lu-labelled Miltuximab® as a targeted beta therapy, in a mouse xenograft model of human prostate cancer.
Male BALB/c nude mice were inoculated subcutaneously with GPC-1-positive DU-145 PCa cells. In imaging and biodistribution studies, mice bearing palpable tumours received (a) 2.62 MBq
ZrZr-DFO-Miltuximab® followed by PET-CT imaging, or (b) 6 MBq
LuLu-DOTA-Miltuximab® by Cerenkov imaging, and ex vivo assessment of biodistribution. In an initial tumour efficacy study, mice bearing DU-145 tumours were administered intravenously with 6 MBq
LuLu-DOTA-Miltuximab® or control DOTA-Miltuximab® then euthanised after 27 days. In a subsequent survival efficacy study, tumour-bearing mice were given 3 or 10 MBq of
LuLu-DOTA-Miltuximab®, or control, and followed up to 120 days.
Antibody accumulation in DU-145 xenografts was detected by PET-CT imaging using
ZrZr-DFO-Miltuximab® and confirmed by Cerenkov luminescence imaging post injection of
LuLu-DOTA-Miltuximab®. Antibody accumulation was higher (% IA/g) in tumours than other organs across multiple time points. A single injection with 6 MBq of
LuLu-DOTA-Miltuximab® significantly inhibited tumour growth as compared with DOTA-Miltuximab® (control). In the survival study, mice treated with 10 MBq
LuLu-DOTA-Miltuximab® had significantly prolonged survival (mean 85 days) versus control (45 days), an effect associated with increased cancer cell apoptosis. Tissue histopathology assessment showed no abnormalities associated with
LuLu-DOTA-Miltuximab®, in line with other observations of tolerability, including body weight stability.
These findings demonstrate the potential utility of Miltuximab® as a PET imaging agent (
ZrZr-DFO-Miltuximab®) and a beta therapy (
LuLu-DOTA-Miltuximab®) in patients with PCa or other GPC-1 expressing tumours.
PDF
