Abstract: Collagen alignment has shown clinical significance in a variety of diseases. For instance, vulvar lichen sclerosus (VLS) is characterized by homogenization of collagen fibers with increasing risk of malignant transformation. To date, a variety of imaging techniques have been developed to visualize collagen fibers. However, few works focused on quantifying the alignment quality of collagen fiber. To assess the level of disorder of local fiber orientation, the homogeneity index (HI) based on limiting entropy is proposed as an indicator of disorder. Our proposed methods are validated by verification experiments on Poly Lactic Acid (PLA) filament phantoms with controlled alignment quality of fibers. A case study on 20 VLS tissue biopsies and 14 normal tissue biopsies shows that HI ca

Abstract: This paper reports a new type of augmented reality (AR) system that integrates a Microsoft HoloLens device with a three-dimensional (3D) point tracking module for medical training and telementored surgery. In this system, a stereo camera is used to track the 3D position of a scalpel and transfer its coordinates wirelessly to a HoloLens device. In the scenario of surgical training, a virtual surgical scene with pre-recorded surgical annotations is superimposed with the actual surgical scene so that the surgical trainee is able to operate following virtual instructions. In the scenario of telementored surgery, the virtual surgical scene is co-registered with the actual surgical scene so that the virtual scalpel remotely mentored by an experienced surgeon provides the AR guidance fo

Abstract: Retinal diseases and systemic diseases, such as diabetic retinopathy (DR) and Alzheimer’s disease, may manifest themselves in the retina, changing the retinal oxygen saturation (SO2) level or the retinal vascular structures. Recent studies explored the correlation of diseases with either retina vascular structures or SO2 level, but not both due to the lack of proper instrument or methodology. In this study, we applied a dual-modal fundus camera and developed a deep learning-based analysis method to simultaneously acquire and quantify the SO2 and vascular structures. Deep learning was used to automatically locate the optic discs and segment arterioles and venules of the blood vessels. We then sought to apply machine learning methods, such as random forest (RF) and support vector m

Abstract: We propose a compound interfacial shearing (CIS) process for versatile production of monodisperse Janus emulsions with controllable structural and topographic features. The process induces an active periodic force to decouple material and process parameters, enables independent control of compartmental features in Janus emulsions, and facilitates inline and on-demand generation of various geometric features for a large variety of process parameters and material properties. Janus emulsions of poly(ethylene glycol) diacrylate (PEGDA) with a controlled number of compartments are produced by CIS and photopolymerized to form micro-hydrogels with designated interfacial curvatures. PEGDA micro-hydrogels can be further modified to achieve anisotropy of surface or internal features by the

Abstract: While artificially encoded microfibers inspired by biosynthetic fibrous microstructures are drawing considerable research attention, their practical applications are hindered by multiple limitations. Here, a programmable dynamic interfacial spinning (DIS) process is proposed for producing volume-encoded microfibers with superior encoding capacity and reliability. The produced microfibers comprise a sheath of deformed hydrogel encapsulating sequentially aligned droplets, with their morphologies controllable by adjusting the flow rates of the corresponding fluids and the vibration parameters of the spinning nozzle. In particular, microfibers with volumetric encoding of inner droplet sequence are constructed for information storage and encryption. With appropriate functionalization

Abstract: Nonspherical liquid metal microparticles (NLMs) show extraordinary potential in various applications due to their multifunctional and structural advantages. To one-step-produce shaped NLMs with high efficiency, high controllability, and free of template, a facile microfluidic strategy named rotary flow shearing (RFS) is reported. A high-speed viscous shearing flow is provided by two counter-rotating rotors in the carrier fluid, inducing continuous pinch-off of liquid metal flowing from a capillary tube positioned in face of the slit between two rotors. The real-time oxidation realizes the rapid solidification of the pinching neck and the liquid metal surface during the RFS process, resulting in massive NLMs. Different from other microfluidic methods, the RFS enables tunable shape

Abstract: Accurate delivery of therapeutics to tumor regions and effective sparing of normal tissue structures are important principles for the treatment of widespread metastases or malignant lesions in close proximity to vital organs. However, the currently available drug delivery techniques do not support precise drug release within the identified disease margins. We propose a tailored drug delivery strategy that utilizes a photo-responsive material in combination with tumor margin imaging for automated and tailored release of therapeutics. As a proof of concept, a poly(ethylene oxide)-b-PSPA (PEO-b-PSPA) diblock copolymer is synthesized by spiropyran (SP) polymerization. A photo-responsive membrane (PRM) is formed and irradiated with light sources of different wavelengths. Switching irr

Abstract: Developing low-cost yet efficient oxygen reduction reaction (ORR) electrocatalysts is of paramount importance for the widespread application of renewable energy technologies. Here, a promising catalyst of the Co–Ni nanoalloy–organic framework (Co–Ni NOF) that significantly accelerates the ORR kinetics process has been synthesized by a straightforward pyrolysis strategy. This Co–Ni NOF catalyst with robust stability and strong methanol tolerance exhibits remarkable ORR activity with an excellent half-wave potential of 0.88 V (30 mV superior to that of commercial Pt/C) and an outstanding kinetic current density of 162.9 mA/cm2 at 0.80 V in 0.1 M KOH, which is 17 times that of Pt/C and outperforms most non-noble catalysts reported so far. The electronic structure characterizations d

Abstract: Biomedical optical imaging is playing an important role in diagnosis and treatment of various diseases. However, the accuracy and the reproducibility of an optical imaging device are greatly affected by the performance characteristics of its components, the test environment, and the operations. Therefore, it is necessary to calibrate these devices by traceable phantom standards. However, most of the currently available phantoms are homogeneous phantoms that cannot simulate multimodal and dynamic characteristics of biological tissue. Here, we show the fabrication of heterogeneous tissue-simulating phantoms using a production line integrating a spin coating module, a polyjet module, a fused deposition modeling (FDM) module, and an automatic control framework. The structural informa

Abstract: Stimuli-responsive microcarriers have received considerable attention in a variety of fields, including disease diagnosis, drug delivery, sensing, and imaging. Here, we report the generation of multiple-responsive perfluorocarbon-loaded magnetic hydrogel microcapsules (PMHMs) with uniform size for magnetic controlled ultrasound (US) and laser activation. The PMHMs are fabricated by a novel coaxial interface shearing (CIS) method based on the mechanism of liquid bridge formation and fracture. Perfluorocarbon and iron oxide magnetic nanoparticles are used as US-responsive and photothermal absorption medium, respectively, and magnetic nanoparticles are also used for magnetic-controlled targeting. Moreover, the size, structure, and function of the prepared biocompatible PMHMs can be

Abstract: We propose a coaxial oblique interface shearing (COIS) process for one-step generation of double emulsions which are synchronously sorted with spatial gradient distributions. As a coaxial needle supplying the inner and outer liquids obliquely vibrates across an air-liquid interface, the pinch-off of the compound liquid neck arises and the resultant double emulsions moves with tunable lateral displacements in the receiving phase. In the COIS process, the morphology and size of the double emulsions are heavily dependent on the vibration frequency and the inner and outer liquid flow rates. The lateral droplet displacements changing with process parameters can be precisely controlled in experiments and predicted theoretically by the Stokes drift model. Furthermore, the feasibility of

Abstract: Effective delivery of chemotherapeutics with minimal toxicity and maximal outcome is clinically important but technically challenging. Here, we synthesize a complex of doxorubicin (DOX)-loaded magneto-liposome (DOX-ML) microbubbles (DOX-ML-MBs) for magnetically responsive and ultrasonically sensitive delivery of anticancer therapies with enhanced efficiency. Citrate-stabilized iron oxide nanoparticles (MNs) of 6.8 +/- 1.36 nm were synthesized, loaded with DOX in the core of oligolamellar vesicles of 172 +/- 9.2 nm, and covalently conjugated with perfluorocarbon (PFC)-gas-loaded microbubbles to form DOX-ML-MBs of approximately 4 mum. DOX-ML-MBs exhibited significant magnetism and were able to release chemotherapeutics and DOX-MLs instantly upon exposure to ultrasound (US) pulses.