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.

Abstract: A coaxial projective imaging (CPI) module acquires surgical scene images from the local site of surgery, transfers them wirelessly to the remote site, and projects instructive annotations to the surgical field. At the remote site, the surgical scene images are displayed, and the instructive annotations from a surgical specialist are wirelessly transferred back to the local site in order to guide the surgical intervention by a less experienced surgeon. The CPI module achieves seamless imaging of the surgical field and accurate projection of the instructive annotations, by a coaxial optical path design that couples the imaging arm with the projection arm and by a color correction algorithm that recovers the true color of the surgical scene. Our benchtop study of tele-guided interve

Abstract: Microencapsulation of pesticide can reduce mammalian toxicity, phyto-toxicity, and protect the pesticides from rapid environmental degradation. The aim of this study was to develop a liquid-driven coaxial flow focusing (LDCFF) process for fabricating pesticide-loaded microcapsules having high encapsulation efficiency, loading efficiency and yield. We have optimized and evaluated the effects of process parameters on the size and morphology of pesticide-loaded microcapsules. The release of pesticides from pesticide-loaded microcapsules has sustained release profiles, which depends on their core-shell structure and shell material degradation process. LDCFF process enables successful encapsulation of pesticides in microcapsules with tunable characteristics important in pesticide appl

Abstract: We propose a projective navigation system for fluorescence imaging and image display in a natural mode of visual perception. The system consists of an excitation light source, a monochromatic charge coupled device (CCD) camera, a host computer, a projector, a proximity sensor and a Complementary metal-oxide-semiconductor (CMOS) camera. With perspective transformation and calibration, our surgical navigation system is able to achieve an overall imaging speed higher than 60 frames per second, with a latency of 330 ms, a spatial sensitivity better than 0.5 mm in both vertical and horizontal directions, and a projection bias less than 1 mm. The technical feasibility of image-guided surgery is demonstrated in both agar-agar gel phantoms and an ex vivo chicken breast model embedding In

Abstract: Optical phantoms are commonly used to validate and calibrate biomedical optical devices in order to ensure accurate measurement of optical properties in biological tissue. However, commonly used optical phantoms are based on homogenous materials that reflect neither optical properties nor multi-layer heterogeneities of biological tissue. Using these phantoms for optical calibration may result in significant bias in biological measurement. We propose to characterize and fabricate tissue simulating phantoms that simulate not only the multi-layer heterogeneities but also optical properties of biological tissue. The tissue characterization module detects tissue structural and functional properties in vivo. The phantom printing module generates 3D tissue structures at different scales

Abstract: Simultaneous and quantitative assessment of multiple tissue parameters may facilitate more effective diagnosis and therapy in many clinical applications, such as wound healing. However, existing wound assessment methods are typically subjective and qualitative, with the need for sequential data acquisition and coregistration between modalities, and lack of reliable standards for performance evaluation or calibration. To overcome these limitations, we developed a multimodal imaging system for quasi-simultaneous assessment of cutaneous tissue oxygenation and perfusion in a quantitative and noninvasive fashion. The system integrated multispectral and laser speckle imaging technologies into one experimental setup. Tissue oxygenation and perfusion were reconstructed by advanced algori

Abstract: We propose a handheld projective imaging device for orthotopic projection of near-infrared fluorescence images onto target biological tissue at visible wavelengths without any additional visual aid. The device integrates a laser diode light source module, a camera module, a projector, an ultrasonic distance sensor, a Raspberry Pi single-board computer, and a battery module in a rugged handheld unit. It is calibrated at the detected working distance for seamless coregistration between fluorescence emission and projective imaging at the target tissue site. The proposed device is able to achieve a projection resolution higher than 314 mum and a planar projection bias less than 1 mm at a projection field of view of 58 x 108 mm2 and a working distance of 27 cm. Technical feasibility f

Abstract: Phantoms simulating polarization characteristics of soft tissue play an important role in the development, calibration, and validation of diagnostic polarized imaging devices and of therapeutic strategy, in both laboratory and clinical settings. We propose to fabricate optical phantoms that simulate polarization characteristics of dense fibrous tissues by bonding electrospun polylactic acid (PLA) fibers between polydimethylsiloxane (PDMS) substrate with a groove. Increasing the rotational speed of an electrospinning collector helps improve the orientation of the electrospun fibers. The phantoms simulate the polarization characteristics of dense fibrous tissue of collagenous fibroma and healthy skin with high fidelity. Our experiments demonstrate the technical potential of using s

Abstract: Retinal vessel oxygen supply is important for retinal tissue metabolism. Commonly used retinal vessel oximetry devices are based on dual-wavelength spectral measurement of oxyhemoglobin and deoxyhemoglobin. However, there is no traceable standard for reliable calibration of these devices. In this study, we developed a fundus-simulating phantom that closely mimicked the optical properties of human fundus tissues. Microchannels of precisely controlled topological structures were produced by soft lithography to simulate the retinal vasculature. Optical properties of the phantom were adjusted by adding scattering and absorption agents to simulate different concentrations of fundus pigments. The developed phantom was used to calibrate the linear correlation between oxygen saturation (

Abstract: Stimuli-responsive microcarriers (SRMs) based on multiple emulsions can be widely used in advanced drug delivery, tissue engineering, biosensing, and cell biology. Here a simple and effective compound interface shearing (CIS) method is proposed to one-step produce SRMs for controlled ultrasound (US) activation. In the CIS process, a coaxial needle supplying the core and shell liquids vibrates periodically across a free gas-liquid surface, resulting in the pinch-off of a compound liquid neck for on-demand generation of multiple emulsions. The CIS process is free of confined walls with a pure interface shearing mechanism. Perfectly uniform SRMs with tunable core-shell volume ratios can be produced, following a scaling law of their size as a function of the liquid flow rates and the