Thin-film transistor (TFT)-driven full-color organic light-emitting diodes (OLEDs) with vertically stacked structures are developed herein using photolithography processes, which allow for ...high-resolution displays of over 2,000 pixels per inch. Vertical stacking of OLEDs by the photolithography process is technically challenging, as OLEDs are vulnerable to moisture, oxygen, solutions for photolithography processes, and temperatures over 100 °C. In this study, we develop a low-temperature processed Al
O
/SiN
bilayered protection layer, which stably protects the OLEDs from photolithography process solutions, as well as from moisture and oxygen. As a result, transparent intermediate electrodes are patterned on top of the OLED elements without degrading the OLED, thereby enabling to fabricate the vertically stacked OLED. The aperture ratio of the full-color-driven OLED pixel is approximately twice as large as conventional sub-pixel structures, due to geometric advantage, despite the TFT integration. To the best of our knowledge, we first demonstrate the TFT-driven vertically stacked full-color OLED.
The extraction of interstitial fluid (ISF) from skin using microneedles (MNs) has attracted growing interest in recent years due to its potential for minimally invasive diagnostics and biosensors. ...ISF collection by absorption into a hydrogel MN patch is a promising way that requires the materials to have outstanding swelling ability. Here, a gelatin methacryloyl (GelMA) patch is developed with an 11 × 11 array of MNs for minimally invasive sampling of ISF. The properties of the patch can be tuned by altering the concentration of the GelMA prepolymer and the crosslinking time; patches are created with swelling ratios between 293% and 423% and compressive moduli between 3.34 MPa and 7.23 MPa. The optimized GelMA MN patch demonstrates efficient extraction of ISF. Furthermore, it efficiently and quantitatively detects glucose and vancomycin in ISF in an in vivo study. This minimally invasive approach of extracting ISF with a GelMA MN patch has the potential to complement blood sampling for the monitoring of target molecules from patients.
A microneedle patch based on gelatin methacryloyl is developed for minimally invasive sampling of interstitial fluid (ISF). The tunable patch can be altered by changing the prepolymer concentration and crosslinking time. Furthermore, the microneedle approach efficiently detects glucose and vancomycin in ISF. This ISF extraction strategy is one potential method for detecting target molecules in clinical practice.
Mesenchymal stem cells (MSCs) have been widely used for regenerative therapy. In most current clinical applications, MSCs are delivered by injection but face significant issues with cell viability ...and penetration into the target tissue due to a limited migration capacity. Some therapies have attempted to improve MSC stability by their encapsulation within biomaterials; however, these treatments still require an enormous number of cells to achieve therapeutic efficacy due to low efficiency. Additionally, while local injection allows for targeted delivery, injections with conventional syringes are highly invasive. Due to the challenges associated with stem cell delivery, a local and minimally invasive approach with high efficiency and improved cell viability is highly desired. In this study, a detachable hybrid microneedle depot (d‐HMND) for cell delivery is presented. The system consists of an array of microneedles with an outer poly(lactic‐co‐glycolic) acid shell and an internal gelatin methacryloyl (GelMA)‐MSC mixture (GMM). The GMM is characterized and optimized for cell viability and mechanical strength of the d‐HMND required to penetrate mouse skin tissue is also determined. MSC viability and function within the d‐HMND is characterized in vitro and the regenerative efficacy of the d‐HMND is demonstrated in vivo using a mouse skin wound model.
A detachable hybrid microneedle depot made up of gelatin methacryloyl and poly(lactic‐coglycolic) acid, both of which are biocompatible and biodegradable, is engineered on a flexible patch for delivering mesenchymal stem cells to a variety of tissues and organs for tissue regeneration.
Bridging the gap between findings in preclinical 2D cell culture models and in vivo tissue cultures has been challenging; the simple microenvironment of 2D monolayer culture systems may not capture ...the cellular response to drugs accurately. Three‐dimensional organotypic models have gained increasing interest due to their ability to recreate precise cellular organizations. These models facilitate investigation of the interactions between different sub‐tissue level components through providing physiologically relevant microenvironments for cells in vitro. The incorporation of human‐sourced tissues into these models further enables personalized prediction of drug responses. Integration of microfluidic units into the 3D models can be used to control their local environment, dynamic simulation of cell behaviors, and real‐time readout of drug testing data. Cancer and immune system related diseases are severe burdens to our health care system and have created an urgent need for high‐throughput, and effective drug development plans. This review focuses on recent progress in the development of “cancer‐on‐a‐chip” and “immune organs‐on‐a‐chip” systems designed to study disease progression and predict drug‐induced responses. Future challenges and opportunities are also discussed.
Organ‐on‐a‐chip systems can provide high‐throughput platforms for drug development, which could potentially bridge the gap between 2D cell culture and animal models. With recent breakthroughs in anticancer immunotherapies, there is an increasing interest in organotypic models for anti‐cancer immunotherapy development. This study reviews current progress in cancer‐on‐a‐chip and immune organs‐on‐a‐chip systems with an emphasis on their potential for drug development.
Viral infection is one of the leading causes of mortality worldwide. The growth of globalization significantly increases the risk of virus spreading, making it a global threat to future public ...health. In particular, the ongoing coronavirus disease 2019 (COVID‐19) pandemic outbreak emphasizes the importance of devices and methods for rapid, sensitive, and cost‐effective diagnosis of viral infections in the early stages by which their quick and global spread can be controlled. Micro and nanoscale technologies have attracted tremendous attention in recent years for a variety of medical and biological applications, especially in developing diagnostic platforms for rapid and accurate detection of viral diseases. This review addresses advances of microneedles, microchip‐based integrated platforms, and nano‐ and microparticles for sampling, sample processing, enrichment, amplification, and detection of viral particles and antigens related to the diagnosis of viral diseases. Additionally, methods for the fabrication of microchip‐based devices and commercially used devices are described. Finally, challenges and prospects on the development of micro and nanotechnologies for the early diagnosis of viral diseases are highlighted.
Viral infections are the leading causes of mortality worldwide. Micro and nanoscale technologies have been used to develop diagnostic platforms for rapid and accurate detection of viral diseases. Here, these technologies are reviewed for sampling, sample processing, enrichment, amplification, and detection of viral particles and antigens. Challenges and future directions in this area are highlighted.
Cancer immunotherapies, including immune checkpoint inhibitor (ICI)‐based therapies, have revolutionized cancer treatment. However, patient response to ICIs is highly variable, necessitating the ...development of methods to quickly assess efficacy. In this study, an array of miniaturized bioreactors has been developed to model tumor‐immune interactions. This immunotherapeutic high‐throughput observation chamber (iHOC) is designed to test the effect of anti‐PD‐1 antibodies on cancer spheroid (MDA‐MB‐231, PD‐L1+) and T cell (Jurkat) interactions. This system facilitates facile monitoring of T cell inhibition and reactivation using metrics such as tumor infiltration and interleukin‐2 (IL‐2) secretion. Status of the tumor‐immune interactions can be easily captured within the iHOC by measuring IL‐2 concentration using a micropillar array where sensitive, quantitative detection is allowed after antibody coating on the surface of array. The iHOC is a platform that can be used to model and monitor cancer‐immune interactions in response to immunotherapy in a high‐throughput manner.
Patient responses to immune checkpoint inhibitor (ICI)‐based therapies are highly variable, calling for a rapid evaluation approach. Here, a cancer‐on‐a‐chip platform is designed to monitor ICI‐associated cancer‐immune interactions between cancer spheroids and T cells in a high‐throughput manner. The system is a promising screening platform for drug discovery, drug safety assessment, and personalized medicine.
At present, the remediation of heavy-metal polluted soil is a considerable problem. In this study, in situ immobilization field experiments were conducted by planting rice (Oryza sativa L.) in Cd ...contaminated paddy soil to determine the optimal remediation mode that would reduce the accumulation of Cd in brown grain. Sepiolite and palygorskite were utilized as amendments, while ordinary and low Cd-accumulating rice cultivars were selected as model plants. The remediation effects of the amendments on the soil and rice were investigated and the potential immobilization mechanisms were analyzed using X-ray diffraction and X-ray photoelectron spectroscopy. The application of sepiolite and palygorskite was found to increase the pH value of the paddy soil, by varying amounts, and significantly reduce the HCl, TCLP, CaCl2, and NH4OAc-extractable Cd concentrations resulting in a notable decrease in the Cd concentration in brown rice. Both sepiolite and palygorskite were found to reduce exchangeable Cd concentrations and increase the carbonate-bound and residual fractions in paddy soil. Precipitation of Cd as carbonates or hydroxides and surface complexation were the main immobilization mechanisms for sepiolite and palygorskite. The concentration of Cd in brown rice of the low Cd-accumulating cultivar from the control plot was 0.72mg·kg−1. Sepiolite treatment reduced the value to 0.18mg·kg−1 below the maximum levels reported by Codex Stan 193-1995 and the national standard of China. It was concluded that chemical immobilization combined with crop cultivar selection could be a suitable proposal for crop safety regulation and sustainable agriculture.
Combination of chemical immobilization and low Cd accumulating rice cultivar.
In situ chemical immobilization can significantly decrease the bioavailability and bioaccessibility of cadmium in paddy soil. Meanwhile, selection and breeding of low Cd accumulating cultivars is an environmentally friendly and cost effective method for reducing the risk of contamination from Cd in food. The results of this study suggested that safer food production was more likely to be achievable by combining low Cd accumulating cultivars with in situ immobilizing agent amendment of soils. Display omitted
•Sepiolite and palygorskite significantly reduced phytoavailable Cd in paddy soils.•Precipitation and surface complexation were main immobilization mechanisms.•Combination of chemical immobilization and low accumulating cultivar was recommended.
Transdermal delivery of water‐insoluble drugs via hydrogel‐based microneedle (MN) arrays is crucial for improving their therapeutic efficacies. However, direct loading of water‐insoluble drug into ...hydrophilic matrices remains challenging. Here, a biodegradable MN array patch that is fabricated from naturally derived polymer conjugates of gelatin methacryloyl and β‐cyclodextrin (GelMA‐β‐CD) is reported. When curcumin, an unstable and water‐insoluble anticancer drug, is loaded as a model drug, its stability and solubility are improved due to the formation of an inclusion complex. The polymer‐drug complex GelMA‐β‐CD/CUR can be formulated into MN arrays with sufficient mechanical strength for skin penetration and tunable drug release profile. Anticancer efficacy of released curcumin is observed in three‐dimensional B16F10 melanoma models. The GelMA‐β‐CD/CUR MN exhibits relatively higher therapeutic efficacy through more localized and deeper penetrated manner compared with a control nontransdermal patch. In vivo studies also verify biocompatibility and degradability of the GelMA‐β‐CD MN arrays patch.
A hydrogel microneedle (MN) patch based on naturally derived gelatin methacryloyl and β‐cyclodextrin conjugates is developed for transdermal delivery of water‐insoluble drugs. Tunable drug release profiles and enhanced drug stability are demonstrated via curcumin as a model drug. The newly developed MN patch possesses good biocompatibility that can potentially be used for various pharmaceutical applications.
Exosomes, a form of small extracellular vesicles, play a crucial role in the metastasis of cancers and thus are investigated as potential biomarkers for cancer diagnosis. However, conventional ...detection methods like immune‐based assay and microRNA analyses are expensive and require tedious pretreatments and lengthy analysis time. Since exosomes related to cancers are reported to exist in tears, a poly(2‐hydroxyethyl methacrylate) contact lens embedded with antibody‐conjugated signaling microchambers (ACSM‐PCL) capable of detecting tear exosomes is reported. The ACSM‐PCL exhibits high optical transparency and mechanical properties, along with extraordinary biocompatibility and good sensitivity to exosomes. A gold nanoparticle colorimetric assay is employed to visualize captured exosomes. The ACSM‐PCL can detect exosomes in the pH range of 6.5–7.4 (similar to the human tear pH) and have a strong recovery yield in bovine serum albumin solutions. In particular, the ACSM‐PCL can detect exosomes in various solutions, including regular buffer, cell culture media from various cell lines, and human tears. Finally, the ACSM‐PCL can differentiate expression of exosome surface proteins hypothesized as cancer biomarkers. With these encouraging results, this ACSM‐PCL is promised to be the next generation smart contact lens as an easy‐to‐use, rapid, noninvasive monitoring platform of cancer pre‐screening and supportive diagnosis.
Tear exosomes are investigated as potential biomarkers for cancer diagnosis. Here, a soft and transparent poly (2‐hydroxyethyl methacrylate) contact lens embedded with antibody‐conjugated signaling microchambers (ACSM‐PCL) capable of the capture and detection of tear exosomes is reported. The ACSM‐PCL is demonstrated to be an easy‐to‐use, rapid, sensitive, noninvasive monitoring platform for effective exosome monitoring.
We investigate a family of dinuclear dysprosium metallocene single‐molecule magnets (SMMs) bridged by methyl and halogen groups Cp′2Dy(μ‐X)2 (Cp′=cyclopentadienyltrimethylsilane anion; 1: X=CH3−; 2: ...X=Cl−; 3: X=Br−; 4: X=I−). For the first time, the magnetic easy axes of dysprosium metallocene SMMs are experimentally determined, confirming that the orientation of them are perpendicular to the equatorial plane which is made up of dysprosium and bridging atoms. The orientation of the magnetic easy axis for 1 deviates from the normal direction (by 10.3°) due to the stronger equatorial interactions between DyIII and methyl groups. Moreover, its magnetic axes show a temperature‐dependent shifting, which is caused by the competition between exchange interactions and Zeeman interactions. Studies of fluorescence and specific heat as well as ab initio calculations reveal the significant influences of the bridging ligands on their low‐lying exchange‐based energy levels and, consequently, low‐temperature magnetic properties.
The single‐molecule magnets (SMMs) Cp′2Dy(μ‐X)2 (Cp′=cyclopentadienyltrimethylsilane anion; X=CH3−, Cl−, Br−, I−) are investigated. For the first time, the magnetic easy axes of dysprosium metallocene SMMs are experimentally determined, confirming that they are oriented perpendicular to the equatorial plane which is made up of dysprosium and bridging atoms.
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