Millirobots that can adapt to unstructured environments, operate in confined spaces, and interact with a diverse range of objects would be desirable for exploration and biomedical applications. The continued development of millirobots, however, requires simple and scalable fabrication techniques. Here, we propose a minimalist approach to construct millirobots by coating inanimate objects with a composited agglutinate magnetic spray. Our approach enables a variety of one-dimensional (1D), 2D, or 3D objects to be covered with a thin magnetically drivable film (~100 to 250 micrometers in thickness). The film is thin enough to preserve the original size, morphology, and structure of the objects while providing actuation of up to hundreds of times its own weight. Under the actuation of a magnetic field, our millirobots are able to demonstrate a range of locomotive abilities: crawling, walking, and rolling. Moreover, we can reprogram and disintegrate the magnetic film on our millirobots on demand. We leverage these abilities to demonstrate biomedical applications, including catheter navigation and drug delivery.

Two new MOFs based ECL aptasensors showed ultra-sensitivity towards the α-syn oligomer, an important biomarker for Parkinson's disease.

Graft subsidence following anterior cervical reconstruction can result in the loss of sagittal balance and recurring foraminal stenosis. This study examined the implant-endplate interface using a cyclic fatigue loading protocol in an attempt to model the subsidence seen in vivo. The superior endplate from 30 cervical vertebrae (C3 to T1) were harvested and biomechanically tested in axial compression with one of three implants: Fibular allograft; titanium mesh cage packed with cancellous chips; and trabecular metal. Each construct was cyclically loaded from 50 to 250 N for 10,000 cycles. Nondestructive cyclic loading of the cervical endplate-implant construct resulted in a stiffer construct independent of the type of the interbody implant tested. The trabecular metal construct demonstrated significantly more axial stability and significantly less subsidence in comparison to the titanium mesh construct. Although the allograft construct resulted in more subsidence than the trabecular metal construct, the difference was not significant and no difference was found when comparing axial stability. For all constructs, the majority of the subsidence during the cyclic testing occurred during the first 500 cycles and was followed by a more gradual settling in the remaining 9,500 cycles. Keywords: cervical endplate; fatigue; cyclic testing; biomechanics; subsidence Anterior cervical fusion has traditionally been a predictable and reliable surgical technique for treatment of multiple spinal pathologies. [1][2][3] The success has been due to factors that are addressed by the surgical procedure: the removal of the pathologic process; the decompression of the neural elements; the correction of sagittal balance; and the stabilization of the motion segment. Maintenance of sagittal balance and continued stabilization of the motion segment following anterior reconstruction is essential in obtaining a successful clinical outcome. Subsidence of an interbody graft or construct prior to bony fusion can be detrimental to sagittal balance and/or stabilization of the motion segment resulting in recurrent foraminal stenosis.Options available for reconstructing the anterior cervical column include a structural autograft, a structural allograft, a carbon fiber cage, a PEEK cage, a titanium mesh cage, or a trabecular metal spacer. Material properties and interface geometries vary, but the devices function similarly by providing mechanical integrity and stability to the construct while bony fusion takes place. Independent of the device, settling occurs following anterior interbody fusion, 4-6 the amount of which is affected by intraoperative endplate injury or removal, osteoporosis, and the cross-sectional area of the implant. 7,8 Obtaining contact between the endplate and implant surfaces is technically challenging, and a certain amount of settling occurs early post-operatively. With bony implants, additional settling occurs as the graft is resorbed prior to bone fusion. The amount of settling is often <1 mm. Other causes of post-op...

A simple, dual-modular aptasensor for accurate determination of cardiac troponin I (cTnI), a sensitive biomarker of acute myocardial infarction, is reported. It has the parallel output of electrochemiluminescence (ECL) and electrochemical impedance spectroscopy (EIS) based on target-gated transportation of signal probes (luminol/H2O2 or Fe­(CN)6 3–/4–). The sensing capacity is originated from the amino-functionalized mouth margin of the nanochannels in a vertically oriented mesoporous silica film, which was in situ-grown on indium tin oxide-coated glass. With the linkage of glutaraldehyde to couple the aptamer as a trapper, it brings in the high specific target-gated response toward cTnI as decreased ECL or increased EIS. The concentration of cTnI is measurable by the ECL response within a wide linear range from 0.05 pg mL–1 to 10 ng mL–1, as well as the EIS response for a linear range between 0.05 pg mL–1 and 1 ng mL–1. Significantly, the self-verification of these two data from ECL and EIS validated each other with a satisfactory linear correlation (R 2 = 0.999), thereby realizing the more reliable and accurate quantification to avoid false results. The designed strategy is an effective method for detection of cTnI, which is of great potential to apply in clinical detection.

Developing small‐scale soft continuum robots with large‐angle steering capacity and high‐precision manipulation offers broad opportunities in various biomedical settings. However, existing continuum robots reach the bottleneck in actuation on account of the contradiction among small size, compliance actuation, large tender range, high precision, and small dynamic error. Herein, a 3D‐printed millimeter‐scale soft continuum robot with an ultrathin hollow skeleton wall (300 μm) and a large inner‐to‐outer ratio (0.8) is reported. After coating a thin ferromagnetic elastomer layer (≈100–150 μm), the proposed soft continuum robot equipped with hybrid actuation (tendon‐ and magnetic‐driven mode) achieves large‐angle (up to 100°) steering and high‐precision (low to 2 μm for static positioning) micromanipulation simultaneously. Specifically, the robot implements an ultralow dynamic tracking error of ≈10 μm, which is ≈30‐fold improved than the state of art. Combined with a microneedle/knife or nasopharyngeal swab, the robot reveals the potential for versatile biomedical applications, such as drug injection on the target tissue, diseased tissue ablation, and COVID‐19 nasopharyngeal sampling. The proposed millimeter‐scale soft continuum robot presents remarkable advances in large‐range and high‐precise actuation, which provides a new method for miniature continuum robot design and finds broad applications in biomedical engineering.

The accurate assay of cardiac troponin I (cTnI) is very important for acute myocardial infarction (AMI), it also can be employed as an effective index for screening serious patients in COVID-19 pandemic before fatal heart injury to reduce the mortality. A ratiometric sensing strategy was proposed based on electrochemiluminescent (ECL) signal of doxorubicin (Dox)-luminol or the electrochemical (EC) signal of methylene blue (MB) vs. referable EC signal of Dox. The bio-recognitive Tro4-aptamer ensures the high specificity of the sensor by affinity binding to catch cTnI, and the tetrahedral DNA (TDs) on Au/Ti 3 C 2 -MXene built an excellent sensing matrix. An in situ hybrid chain reaction (HCR) amplification greatly improved the sensitivity. The ratiometric sensing responses ECL Dox-luminol / Current Dox or Current MB / Current Dox linearly regressed to cTnI concentration in the range of 0.1 fM-1 pM or 0.1 fM-500 fM with the limit of detection (LOD) as 0.04 fM or 0.1 fM, respectively. Served as the reference signal, Current Dox reflected the variation of sensor, it is very effective to ensure the accuracy of detection to obviate the false results. The proposed biosensors show good specificity, sensitivity, reproducibility and stability, have been applied to determine cTnI in real samples with satisfactory results. They are worth looking forward to be used for screening serious patient of COVID-19 to reduce the mortality, especially in mobile cabin hospital.

This study demonstrates the utility of a preoperative QCT scan in predicting the failure stress of the cervical endplate before total disc replacement. This information may potentially decrease early complications of device subsidence or endplate fracture.

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