Microenvironment-Controlled Micropatterned Microfluidic Model (MMMM) for Biomimetic In Situ Studies

Nanoplasmonic Single-Tumoroid Microarray for Real-Time Secretion Analysis

Organoid tumor models have emerged as a powerful tool in the fields of biology and medicine as such 3D structures grown from tumor cells recapitulate better tumor characteristics, making these tumoroids unique for personalized cancer research. Assessment of their functional behavior, particularly protein secretion, is of significant importance to provide comprehensive insights. Here, a label-free spectroscopic imaging platform is presented with advanced integrated optofluidic nanoplasmonic biosensor that enables real-time secretion analysis from single tumoroids. A novel two-layer microwell design isolates tumoroids, preventing signal interference, and the microarray configuration allows concurrent analysis of multiple tumoroids. The dual imaging capability combining time-lapse plasmonic spectroscopy and bright-field microscopy facilitates simultaneous observation of secretion dynamics, motility, and morphology. The integrated biosensor is demonstrated with colorectal tumoroids derived from both cell lines and patient samples to investigate their vascular endothelial growth factor A (VEGF-A) secretion, growth, and movement under various conditions, including normoxia, hypoxia, and drug treatment. This platform, by offering a label-free approach with nanophotonics to monitor tumoroids, can pave the way for new applications in fundamental biological studies, drug screening, and the development of therapies.

Characterization of a unique attachment organelle: Single-cell force spectroscopy of Giardia duodenalis trophozoites

The unicellular parasite Giardia duodenalis is the causative agent of giardiasis, a gastrointestinal disease with global spread. In its trophozoite form, G. duodenalis can adhere to the human intestinal epithelium and a variety of other, artificial surfaces. Its attachment is facilitated by a unique microtubule-based attachment organelle, the so-called ventral disc. The mechanical function of the ventral disc, however, is still debated. Earlier studies postulated that a dynamic negative pressure under the ventral disc, generated by persistently beating flagella, mediates the attachment. Later studies suggested a suction model based on structural changes of the ventral discs, substrate clutching or grasping, or unspecific contact forces. In this study, we aim to contribute to the understanding of G. duodenalis attachment by investigating detachment characteristics and determining adhesion forces of single trophozoites on a smooth glass surface (RMS = 1.1 ± 0.2 nm) by fluidic force microscopy (FluidFM)-based single-cell force spectroscopy (SCFS). Briefly, viable adherent trophozoites were approached with a FluidFM micropipette, immobilized to the micropipette aperture by negative pressure, and detached from the surface by micropipette retraction while retract force curves were recorded. These force curves displayed novel and so far undescribed characteristics for a microorganism, namely, gradual force increase on the pulled trophozoite, with localization of adhesion force shortly before cell detachment length. Respective adhesion forces reached 7.7 ± 4.2 nN at 1 μm s-1 pulling speed. Importantly, this unique force pattern was different from that of other eukaryotic cells such as Candida albicans or oral keratinocytes, considered for comparison in this study. The latter both displayed a force pattern with force peaks of different values or force plateaus (for keratinocytes) indicative of breakage of molecular bonds of cell-anchored classes of adhesion molecules or membrane components. Furthermore, the attachment mode of G. duodenalis trophozoites was mechanically resilient to tensile forces, when the pulling speeds were raised up to 10 μm s-1 and adhesion forces increased to 28.7 ± 10.5 nN. Taken together, comparative SCSF revealed novel and unique retract force curve characteristics for attached G. duodenalis, suggesting a ligand-independent suction mechanism, that differ from those of other well described eukaryotes.

Minimum Minutes Machine-Learning Microfluidic Microbe Monitoring Method (M7)

Frequent outbreaks of viral diseases have brought substantial negative impacts on society and the economy, and they are very difficult to detect, as the concentration of viral aerosols in the air is low and the composition is complex. The traditional detection method is manually collection and re-detection, being cumbersome and time-consuming. Here we propose a virus aerosol detection method based on microfluidic inertial separation and spectroscopic analysis technology to rapidly and accurately detect aerosol particles in the air. The microfluidic chip is designed based on the principles of inertial separation and laminar flow characteristics, resulting in an average separation efficiency of 95.99% for 2 μm particles. We build a microfluidic chip composite spectrometer detection platform to capture the spectral information on aerosol particles dynamically. By employing machine-learning techniques, we can accurately classify different types of aerosol particles. The entire experiment took less than 30 min as compared with hours by PCR detection. Furthermore, our model achieves an accuracy of 97.87% in identifying virus aerosols, which is comparable to the results obtained from PCR detection.

Advances in the Application of Black Phosphorus-Based Composite Biomedical Materials in the Field of Tissue Engineering

Black Phosphorus (BP) is a new semiconductor material with excellent biocompatibility, degradability, and optical and electrophysical properties. A growing number of studies show that BP has high potential applications in the biomedical field. This article aims to systematically review the research progress of BP composite medical materials in the field of tissue engineering, mining BP in bone regeneration, skin repair, nerve repair, inflammation, treatment methods, and the application mechanism. Furthermore, the paper discusses the shortcomings and future recommendations related to the development of BP. These shortcomings include stability, photothermal conversion capacity, preparation process, and other related issues. However, despite these challenges, the utilization of BP-based medical materials holds immense promise in revolutionizing the field of tissue repair.

Plant exosome nanovesicles (PENs): green delivery platforms

Natural plants have been attracting increasing attention in biomedical research due to their numerous benefits. Plant exosome-derived vesicles, some of the plant's components, are small nanoscale vesicles secreted by plant cells. These vesicles are rich in bioactive substances and play significant roles in intercellular communication, information transfer, and maintaining homeostasis in organisms. They also hold promise for treating diseases, and their vesicular structures make them suitable carriers for drug delivery, with large-scale production feasible. Therefore, this paper aims to provide an overview of nanovesicles from different plant sources and their extraction methods. We also outline the biological activities of nanovesicles, including their anti-inflammatory, anti-viral, and anti-tumor properties, and systematically introduce their applications in drug delivery. These applications include transdermal delivery, targeted drug delivery, gene delivery, and their potential use in the modern food industry. This review provides new ideas and methods for future research on plant exosomes, including their empowerment by artificial intelligence and gene editing, as well as their potential application in the biomedicine, food, and agriculture industries.

Living Anisotropic Structural Color Hydrogels for Cardiotoxicity Screening

Environmental toxins can result in serious and fatal damage in the human heart, while the development of a viable stratagem for assessing the effects of environmental toxins on human cardiac tissue is still a challenge. Herein, we present a heart-on-a-chip based on human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) cultured living anisotropic structural color hydrogels for cardiotoxicity screening. Such anisotropic structural color hydrogels with a conductive parallel carbon nanotube (CNT) upper layer, gelatin methacryloyl (GelMA) interlayer, and inverse opal bottom layer were fabricated by a sandwich replicating approach. The inverse opal structure endowed the anisotropic hydrogels with stable structural color property, while the parallel and conductive CNTs could induce the hiPSC-CMs to grow in a directional manner with consistent autonomous beating. Notably, the resultant hiPSC-CM-cultured hydrogel exhibited synchronous shifts in structural color, responding to contraction and relaxation of hiPSC-CMs, offering a visual platform for monitoring cell activity. Given these features, the hiPSC-CM-cultured living anisotropic structural color hydrogels were integrated into a heart-on-a-chip, which provided a superior cardiotoxicity screening platform for environmental toxins.

Deep learning with microfluidics for on-chip droplet generation, control, and analysis

Droplet microfluidics has gained widespread attention in recent years due to its advantages of high throughput, high integration, high sensitivity and low power consumption in droplet-based micro-reaction. Meanwhile, with the rapid development of computer technology over the past decade, deep learning architectures have been able to process vast amounts of data from various research fields. Nowadays, interdisciplinarity plays an increasingly important role in modern research, and deep learning has contributed greatly to the advancement of many professions. Consequently, intelligent microfluidics has emerged as the times require, and possesses broad prospects in the development of automated and intelligent devices for integrating the merits of microfluidic technology and artificial intelligence. In this article, we provide a general review of the evolution of intelligent microfluidics and some applications related to deep learning, mainly in droplet generation, control, and analysis. We also present the challenges and emerging opportunities in this field.

Living microecological hydrogels for wound healing

Chronic hard-to-heal wounds draw great attention worldwide, as their treatments are limited by infections and hypoxia. Inspired by the natural oxygen production capacity of algae and the competitive advantage of beneficial bacteria over other microbes, we presented a living microecological hydrogel (LMH) with functionalized Chlorella and Bacillus subtilis encapsulation to realize continuous oxygen delivery and anti-infections for promoting chronic wound healing. As the hydrogel consisted of thermosensitive Pluronic F-127 and wet-adhesive polydopamine, the LMH could keep liquid at a low temperature while quickly solidifying and tightly adhering to the wound bed. It was demonstrated that by optimizing the proportion of the encapsulated microorganism, the Chlorella could continuously produce oxygen to relieve hypoxia and support the proliferation of B. subtilis, while B. subtilis could eliminate the colonized pathogenic bacteria. Thus, the LMH substantially promoted the healing of infected diabetic wounds. These features make the LMH valuable for practical clinical applications.

Liquid Metal Droplets-Based Elastomers from Electric Toothbrush-Inspired Revolving Microfluidics

Liquid metal (LM)-based elastomers have a demonstrated value in flexible electronics. Attempts in this area include the development of multifunctional LM-based elastomers with controllable morphology, superior mechanical performances, and great stability. Herein, inspired by the working principle of electric toothbrushes, a revolving microfluidic system is presented for the generation of LM droplets and construction of desired elastomers. The system involves revolving modules assembled by a needles array and 3D microfluidic channels. LM droplets can be generated with controllable size in a high-throughput manner due to the revolving motion-derived drag force. It is demonstrated that by employing a poly(dimethylsiloxane) (PDMS) matrix as the collection phase, the generated LM droplets can act as conductive fillers for the construction of flexible electronics directly. The resultant LM droplets-based elastomers exhibit high mechanical strength, stable electrical performance, as well as superior self-healing property benefiting from the dynamic exchangeable urea bond of the polymer matrix. Notably, due to the flexible programmable feature of the LM droplets embedded within the elastomers, various patterned LM droplets-based elastomers can be easily achieved. These results indicate that the proposed microfluidic LM droplets-based elastomers have a great potential for promoting the development of flexible electronics.

Bioinspired optical and electrical dual-responsive heart-on-a-chip for hormone testing

Heart-on-chips have emerged as a powerful tool to promote the paradigm innovation in cardiac pathological research and drug development. Attempts are focused on improving microphysiological visuals, enhancing bionic characteristics, as well as expanding their biomedical applications. Herein, inspired by the bright feathers of peacock, we present a novel optical and electrical dual-responsive heart-on-a-chip based on cardiomyocytes hybrid bright MXene structural color hydrogels for hormone toxicity evaluation. Such hydrogels with inverse opal nanostructure are generated by using pregel to replicate MXene-decorated colloidal photonic crystal (PhC) array templates. The attendant MXene in the hydrogels could not only enhance the saturation of structural color, but also ensure the composite hydrogel with excellent electroconductivity to facilitate the synergetic beating of their surface cultured cardiomyocytes. In this case, the hydrogels would undergo a synchronous deformation and generate shift in corresponding photonic band gap and structural color, which could be employed as visual signal for self-reporting of the cardiomyocyte mechanics. Based on these features, we demonstrated the practical value of the optical and electrical dual-responsive structural color MXene hydrogels constructed heart-on-a-chip in hormone toxicity testing. These results indicated that the proposed heart-on-a-chip might find broad prospects in drug screening, biological research, and so on.

Primary Human Pancreatic Cancer Cells Cultivation in Microfluidic Hydrogel Microcapsules for Drug Evaluation

Chemotherapy is an essential postoperative treatment for pancreatic cancer, while due to the lack of effective drug evaluation platforms, the therapeutic outcomes are hampered by tumor heterogeneity among individuals. Here, a novel microfluidic encapsulated and integrated primary pancreatic cancer cells platform is proposed for biomimetic tumor 3D cultivation and clinical drug evaluation. These primary cells are encapsulated into hydrogel microcapsules of carboxymethyl cellulose cores and alginate shells based on a microfluidic electrospray technique. Benefiting from the good monodispersity, stability, and precise dimensional controllability of the technology, the encapsulated cells can proliferate rapidly and spontaneously form 3D tumor spheroids with highly uniform size and good cell viability. By integrating these encapsulated tumor spheroids into a microfluidic chip with concentration gradient channels and culture chambers, dynamic and high-throughput drug evaluation of different chemotherapy regimens could be realized. It is demonstrated that different patient-derived tumor spheroids show different drug sensitivity on-chip, which is significantly consistent with the clinical follow-up study after the operation. The results demonstrate that the microfluidic encapsulated and integrated tumor spheroids platform has great application potential in clinical drug evaluation.

Smartphone-based platforms implementing microfluidic detection with image-based artificial intelligence

The frequent outbreak of global infectious diseases has prompted the development of rapid and effective diagnostic tools for the early screening of potential patients in point-of-care testing scenarios. With advances in mobile computing power and microfluidic technology, the smartphone-based mobile health platform has drawn significant attention from researchers developing point-of-care testing devices that integrate microfluidic optical detection with artificial intelligence analysis. In this article, we summarize recent progress in these mobile health platforms, including the aspects of microfluidic chips, imaging modalities, supporting components, and the development of software algorithms. We document the application of mobile health platforms in terms of the detection objects, including molecules, viruses, cells, and parasites. Finally, we discuss the prospects for future development of mobile health platforms.

Erythrocyte-Inspired Functional Materials for Biomedical Applications

Erythrocytes are the most abundant cells in the blood. As the results of long-term natural selection, their specific biconcave discoid morphology and cellular composition are responsible for gaining excellent biological performance. Inspired by the intrinsic features of erythrocytes, various artificial biomaterials emerge and find broad prospects in biomedical applications such as therapeutic delivery, bioimaging, and tissue engineering. Here, a comprehensive review from the fabrication to the applications of erythrocyte-inspired functional materials is given. After summarizing the biomaterials mimicking the biological functions of erythrocytes, the synthesis strategies of particles with erythrocyte-inspired morphologies are presented. The emphasis is on practical biomedical applications of these bioinspired functional materials. The perspectives for the future possibilities of the advanced erythrocyte-inspired biomaterials are also discussed. It is hoped that the summary of existing studies can inspire researchers to develop novel biomaterials; thus, accelerating the progress of these biomaterials toward clinical biomedical applications.

Responsive and self-healing structural color supramolecular hydrogel patch for diabetic wound treatment

The treatment of diabetic wounds remains a great challenge for medical community. Here, we present a novel structural color supramolecular hydrogel patch for diabetic wound treatment. This hydrogel patch was created by using N-acryloyl glycinamide (NAGA) and 1-vinyl-1,2,4-triazole (VTZ) mixed supramolecular hydrogel as the inverse opal scaffold, and temperature responsive poly(N-isopropylacrylamide) (PNIPAM) hydrogel loaded with vascular endothelial cell growth factor (VEGF) as a filler. Supramolecular hydrogel renders hydrogel patch with superior mechanical properties, in which NAGA and VTZ also provide self-healing and antibacterial properties, respectively. Besides, as the existence of PNIPAM, the hydrogel patch was endowed with thermal-responsiveness property, which could release actives in response to temperature stimulus. Given these excellent performances, we have demonstrated that the supramolecular hydrogel patch could significantly enhance the wound healing process in diabetes rats by downregulating the expression of inflammatory factors, promoting collagen deposition and angiogenesis. Attractively, due to responsive optical property of inverse opal scaffold, the hydrogel patch could display color-sensing behavior that was suitable for the wound monitoring and management as well as guidance of clinical treatment. These distinctive features indicate that the presented hydrogel patches have huge potential values in biomedical fields.

Subchondral bone-inspired hydrogel scaffold for cartilage regeneration

Promoting the in situ regeneration of cartilage without additional cells or cytokines remains challenging. Here, inspired by the unique microstructures of subchondral bone, a cell and cytokine free hydrogel scaffold for cartilage regeneration was developed via a strategy of directional lyophilization and postcrosslinking. This strategy achieved intersecting microchannels in an orderly arrangement and an aligned ladder-like texture in a semi-interpenetrating hydrogel network. The resulting hydrogel had similar mechanical properties to the native cartilage extracellular matrix. Incorporating chitosan into the rigid network also endowed the hydrogel with excellent hemostatic properties. By delicately tuning the components and postcrosslinking conditions, the hydrogel was further endowed with suitable swelling and degradation properties for cartilage regeneration. In vitro tests showed that the highly biocompatible hydrogel scaffold could facilitate the migration and chondrogenic differentiation of bone marrow mesenchymal stem cells. In vivo results further verified that the hydrogel could promote the in situ regeneration of cartilage in a rat model of osteochondral defects. In summary, the subchondral bone-like hydrogel revealed promising prospects in cartilage regeneration and a variety of bioremediation applications.

Microfluidic chemostatic bioreactor for high-throughput screening and sustainable co-harvesting of biomass and biodiesel in microalgae

As a renewable and sustainable source for energy, environment, and biomedical applications, microalgae and microalgal biodiesel have attracted great attention. However, their applications are confined due to the cost-efficiency of microalgal mass production. One-step strategy and continuous culturing systems could be solutions. However, current studies for optimization throughout microalgae-based biofuel production pipelines are generally derived from the batch culture process. Better tools are needed to study algal growth kinetics in continuous systems. A microfluidic chemostatic bioreactor was presented here, providing low-bioadhesive cultivations for algae in a cooperative environment of gas, nutrition, and temperature (GNT) involved with high throughput. The chip was used to mimic the continuous culture environment of bioreactors. It allowed simultaneously studying of 8 × 8 different chemostatic conditions on algal growth and oil production in parallel on a 7 × 7 cm² footprint. On-chip experiments of batch and continuous cultures of Chlorella. sp. were performed to study growth and lipid accumulation under different nitrogen concentrations. The results demonstrated that microalgal cultures can be regulated to grow and accumulate lipids concurrently, thus enhancing lipid productivity in one step. The developed on-chip culturing condition screening, which was more suitable for continuous bioreactor, was achieved at a half shorter time, 64-times higher throughput, and less reagent consumption. It could be used to establish chemostat cultures in continuous bioreactors which can dramatically accelerate the development of renewable and sustainable algal for CO₂ fixation and biosynthesis and related systems for advanced sustainable energy, food, pharmacy, and agriculture with enormous social and ecological benefits.

Conductive Materials with Elaborate Micro/Nanostructures for Bioelectronics

Bioelectronics, an emerging field with the mutual penetration of biological systems and electronic sciences, allows the quantitative analysis of complicated biosignals together with the dynamic regulation of fateful biological functions. In this area, the development of conductive materials with elaborate micro/nanostructures has been of great significance to the improvement of high-performance bioelectronic devices. Thus, here, a comprehensive and up-to-date summary of relevant research studies on the fabrication and properties of conductive materials with micro/nanostructures and their promising applications and future opportunities in bioelectronic applications is presented. In addition, a critical analysis of the current opportunities and challenges regarding the future developments of conductive materials with elaborate micro/nanostructures for bioelectronic applications is also presented.

Rapid Determination of Phase Diagrams for Biomolecular Liquid-Liquid Phase Separation with Microfluidics

Biomolecular phase separation is currently emerging in both the medical and life science fields. Meanwhile, the application of liquid-liquid phase separation has been extended to many fields including drug discovery, fibrous material fabrication, 3D printing, and polymer design. Although more than 8600 proteins and other synthetic macromolecules are capable of phase separation as recently reported, there is still a lack of a high-throughput approach to quantitatively characterize its phase behaviors. To meet this requirement, here, we proposed fast and high-resolution acquisition of biomolecular phase diagrams using microfluidic chips. Using this platform, we demonstrated the phase behavior of polyU/RRASLRRASLRRASL in a quantitative manner. Up to 1750 concentration conditions can be generated in 140 min. The detection limitation of our device to capture the saturation concentration for phase separation is about 5 times lower than that of the traditional turbidity method. Thus, our results provide a basis for the rapid acquisition of phase diagrams with high-throughput and pave the way for its wide application.

Sorting Gold and Sand (Silica) Using Atomic Force Microscope-Based Dielectrophoresis

Additive manufacturing-also known as 3D printing-has attracted much attention in recent years as a powerful method for the simple and versatile fabrication of complicated three-dimensional structures. However, the current technology still exhibits a limitation in realizing the selective deposition and sorting of various materials contained in the same reservoir, which can contribute significantly to additive printing or manufacturing by enabling simultaneous sorting and deposition of different substances through a single nozzle. Here, we propose a dielectrophoresis (DEP)-based material-selective deposition and sorting technique using a pipette-based quartz tuning fork (QTF)-atomic force microscope (AFM) platform DEPQA and demonstrate multi-material sorting through a single nozzle in ambient conditions. We used Au and silica nanoparticles for sorting and obtained 95% accuracy for spatial separation, which confirmed the surface-enhanced Raman spectroscopy (SERS). To validate the scheme, we also performed a simulation for the system and found qualitative agreement with the experimental results. The method that combines DEP, pipette-based AFM, and SERS may widely expand the unique capabilities of 3D printing and nano-micro patterning for multi-material patterning, materials sorting, and diverse advanced applications.

Artificial intelligence-powered microfluidics for nanomedicine and materials synthesis

Artificial intelligence (AI) is an emerging technology with great potential, and its robust calculation and analysis capabilities are unmatched by traditional calculation tools. With the promotion of deep learning and open-source platforms, the threshold of AI has also become lower. Combining artificial intelligence with traditional fields to create new fields of high research and application value has become a trend. AI has been involved in many disciplines, such as medicine, materials, energy, and economics. The development of AI requires the support of many kinds of data, and microfluidic systems can often mine object data on a large scale to support AI. Due to the excellent synergy between the two technologies, excellent research results have emerged in many fields. In this review, we briefly review AI and microfluidics and introduce some applications of their combination, mainly in nanomedicine and material synthesis. Finally, we discuss the development trend of the combination of the two technologies.

Ca2+-supplying black phosphorus-based scaffolds fabricated with microfluidic technology for osteogenesis

Effective osteogenesis remains a challenge in the treatment of bone defects. The emergence of artificial bone scaffolds provides an attractive solution. In this work, a new biomineralization strategy is proposed to facilitate osteogenesis through sustaining supply of nutrients including phosphorus (P), calcium (Ca), and silicon (Si). We developed black phosphorus (BP)-based, three-dimensional nanocomposite fibrous scaffolds via microfluidic technology to provide a wealth of essential ions for bone defect treatment. The fibrous scaffolds were fabricated from 3D poly (l-lactic acid) (PLLA) nanofibers (3D NFs), BP nanosheets, and hydroxyapatite (HA)-porous SiO2 nanoparticles. The 3D BP@HA NFs possess three advantages: i) stably connected pores allow the easy entrance of bone marrow-derived mesenchymal stem cells (BMSCs) into the interior of the 3D fibrous scaffolds for bone repair and osteogenesis; ii) plentiful nutrients in the NFs strongly improve osteogenic differentiation in the bone repair area; iii) the photothermal effect of fibrous scaffolds promotes the release of elements necessary for bone formation, thus achieving accelerated osteogenesis. Both in vitro and in vivo results demonstrated that the 3D BP@HA NFs, with the assistance of NIR laser, exhibited good performance in promoting bone regeneration. Furthermore, microfluidic technology makes it possible to obtain high-quality 3D BP@HA NFs with low costs, rapid processing, high throughput and mass production, greatly improving the prospects for clinical application. This is also the first BP-based bone scaffold platform that can self-supply Ca2+, which may be the blessedness for older patients with bone defects or patients with damaged bones as a result of calcium loss.

NIR-Responsive Ti3 C2 MXene Colloidal Solution for Curing Purulent Subcutaneous Infection through the "Nanothermal Blade" Effect

Pathogenic microorganisms' infections have always been a difficult clinical challenge and lead to serious health problems. Thus, a new strategy is urgently needed. In this study, a simple preparation method for Ti₃ C₂ MXene colloidal solution is proposed. In vitro, Staphylococcus aureus is treated with 250 µg mL^-1 of Ti₃ C₂ colloidal solution under 5 min of 808 nm near-infrared (NIR) laser irradiation twice. Staphylococcus aureus is eliminated by the "nanothermal blade" effect from Ti₃ C₂ combined with NIR; the antibacterial rate is 99%, which is higher than the antibacterial rate of pure Ti₃ C₂ alone 78%. The antibacterial mechanism underlying this treatment may be that the thermal Ti₃ C₂ nanosheets first transfer heat to the cell membrane, disrupting the membrane structure, disturbing the metabolism and causing leakage of bacterial protein and deoxyribonucleic acid, consequently leading to bacterial death. In vivo results indicate that Ti₃ C₂ colloidal solution under NIR can effectively kill Staphylococcus aureus and prevent inflammation. Moreover, 250 µg mL^-1 Ti₃ C₂ colloidal solution is nontoxic to mouse organs during the therapeutic process. Therefore, Ti₃ C₂ colloidal solution can be an ideal candidate for subcutaneous infection application. The antibacterial mechanism proposed in this study aids the investigation of other MXenes as antibacterial agents.

A three-dimensional pinwheel-shaped paper-based microfluidic analytical device for fluorescence detection of multiple heavy metals in coastal waters by rational device design

Here, we present the rational design of a pinwheel-shaped three-dimensional microfluidic paper-based analytical device (3D-μPAD) for specific, sensitive and multiplexed detection of heavy metals in coastal waters. A more homogeneous permeation of fluids along the chip than common design, even under unskilled performance, has been achieved by the elaborate chip design of the hydrostatic balancing inlet port and uniformly stressed reversible sealing. With the combination of ion imprinted polymer grafted CdTe quantum-dots and fluid accumulation pad, 4 metals (Cu²⁺, Cd²⁺, Pb²⁺, and Hg²⁺) in 1 analysis and 25-fold enrichment for each metal can be simultaneously performed within 20 min, with detection limits of 0.007-0.015 μg/L. It has the ability to selectively recognize these 4 metals in mixtures and immunizing to interferences from components found in coastal waters, which provided results that were in agreement with values gained from atomic absorption. The inexpensive and portable nature as well as the highly sensitive and flexible performance of the new developed 3D-μPAD could make it attractive as an on-site testing approach for marine environmental monitoring.