The characterization of cell traction force on nonflat surfaces with different curvature by elastic hydrogel microspheres.

It is of great importance to study the detachment/attachment behaviors of cells (cancer cell, immune cell, and epithelial cell), as they are closely related with tumor metastasis, immunoreaction, and tissue development at variety scales. To characterize the detachment/attachment during the interaction between cells and substrate, some researchers proposed using cell traction force (CTF) as the indicator. To date, various strategies have been developed to measure the CTF. However, these methods only realize the measurements of cell passive forces on flat cases. To quantify the active CTF on nonflat surfaces, which can better mimic the in vivo case, we employed elastic hydrogel microspheres as a force sensor. The microspheres were fabricated by microfluidic chips with controllable size and mechanical properties to mimic substrate. Cells were cultured on microsphere and the CTF led to the deformation of microsphere. By detecting the morphology information, the CTF exerted by attached cells can be calculated by the in-house numerical code. Using these microspheres, the CTF of various cells (including tumor cell, immunological cell, and epithelium cell) were successfully obtained on nonflat surfaces with different curvature radii. The proposed method provides a versatile platform to measure the CTF with high precision and to understand the detachment/attachment behaviors during physiology processes.

A Janus Microsphere Delivery System Orchestrates Immunomodulation and Osteoinduction by Fine-tuning Release Profiles.

Bone regeneration is a well-orchestrated process synergistically involving inflammation, angiogenesis, and osteogenesis. Therefore, an effective bone graft should be designed to target multiple molecular events and biological demands during the bone healing process. In this study, a biodegradable gelatin methacryloyl (GelMA)-based Janus microsphere delivery system containing calcium phosphate oligomer (CPO) and bone morphogenetic protein-2 (BMP-2) is developed based on natural biological events. The exceptional adjustability of GelMA facilitates the controlled release and on-demand application of biomolecules, and optimized delivery profiles of CPO and BMP-2 are explored. The sustained release of CPO during the initial healing stages contributes to early immunomodulation and promotes mineralization in the late stage. Meanwhile, the administration of BMP-2 at a relatively high concentration within the therapeutic range enhances the osteoinductive property. This delivery system, with fine-tuned release patterns, induces M2 macrophage polarization and creates a conducive immuno-microenvironment, which in turn facilitates effective bone regeneration in vivo. Collectively, this study proposes a bottom-up concept, aiming to develop a user-friendly and easily controlled delivery system targeting individual biological events, which may offer a new perspective on developing function-optimized biomaterials for clinical use.

Antibacterial sequential growth factor delivery from alginate/gelatin methacryloyl microspheres for bone regeneration.

Autologous or allogeneic bone tissue grafts remain the mainstay of treatment for clinical bone defects. However, the risk of infection and donor scarcity in bone grafting pose challenges to the process. Therefore, the development of excellent biomaterial grafts is of great clinical importance for the repair of bone defects. In this study, we used gas-assisted microfluidics to construct double-cross-linked hydrogel microspheres with good biological function based on the ionic cross-linking of Cu2+ with alginate and photo-cross-linking of gelatin methacryloylamide (GelMA) by loading vascular endothelial growth factor (VEGF) and His-tagged bone morphogenetic protein-2 (BMP2) (AGMP@VEGF&BMP2). The Cu2+ component in the microspheres showed good antibacterial and drug-release behavior, whereas VEGF and BMP2 effectively promoted angiogenesis and bone tissue repair. In in vitro and in vivo experiments, the dual cross-linked hydrogel microspheres showed good biological function and biocompatibility. These results demonstrate that AGMP@VEGF&BMP2 microspheres could be used as a bone defect graft substitute to promote effective healing of bone defects and may be applied to other tissue engineering studies.

Long-acting bulleyaconitine A microspheres via intra-articular delivery for multidimensional therapy of rheumatoid arthritis.

Bulleyaconitine A (BLA) is a promising candidate for treating rheumatoid arthritis (RA) with diverse pharmacological activities, including anti-inflammatory, analgesic and bone repair. Herein, the long-acting bulleyaconitine A microspheres (BLA-MS) were developed to treat RA comprehensively by forming drug reservoirs in joint cavities. The BLA-MS were prepared by emulsion/solvent evaporation method. The particle size and distribution were assessed by SEM. The crystalline state was investigated by DSC and PXRD. The drug loading (DL), encapsulation efficiency (EE) and cumulative release in vitro were determined by HPLC. The DL and EE were 23.93 ± 0.38 % and 95.73 ± 1.56 % respectively, and the cumulative release was up to 69 days with a stable release curve. The pharmacodynamic results in collagen induced arthritis (CIA) rats showed a noticeable reduction in paw thickness (5.66 ± 0.32 mm), and the decreasing expression level of PGE2, TNF-α and IL-6 which diminished the infiltration of inflammatory cells, thereby alleviating the progression of erosion and repairing the damaged bones (BV/TV (Bone Volume / Total Volume): 81.97 %, BS/BV (Bone Surface / Bone Volume): 6.08 mm-1). In conclusion, intra-articular injection of BLA-MS should have a promising application in the treatment of RA and may achieve clinical transformation in the future.

3D magnetic flower-spherical Fe2O3-NiO derived from NiFe-layered double hydroxides for the efficient removal of Bensulfuron methyl: Morphological control and bimetallic synergy.

Three-dimensional (3D) magnetic flower-spherical Fe2O3-NiO derived from NiFe-layered double hydroxides (NiFe-LDHs) was fabricated through urea hydrothermal and calcination methods. The as-prepared materials were applied to activate PMS to degrade one of herbicide named Bensulfuron methyl (BSM). Fe2O3-NiO-1 demonstrated the highest catalytic activity and the lowest ions leaching by comparing the performance of LDHs and derivative bimetallic oxide synthesized by co-precipitation method, urea hydrothermal method and direct calcination method. Based on the results of SEM, BET and CV, the high catalytic activity of Fe2O3-NiO-1 originated from 3D morphology, lager specific area and pore size and faster electron transfer capability. The factors influencing the degradation performance were investigated and 0.1 g·L-1 Fe2O3-NiO could effectively activate PMS (1 mmol·L-1) to completely remove 10 mg·L-1 BSM within 30 min at pH 7.0. In Fe2O3-NiO/PMS system, OH, SO4- and 1O2 were produced and contributed to the BSM removal according to the results of EPR and quenching experiments. In order to expand its application range, Fe2O3-NiO/PMS system was used to degrade aniline (AN), sulfamethoxazole (SMZ), phenacetin (PNT), bisphenol A (BPA) and 2,4,6-triclofen (2,4,6-TCP) and the results showed the degradation efficiency could reach 90 % or more. Additionally, the application of catalysts in different actual water samples and the ability of reuse were tested. Based on the strategies of bimetallic synergy and morphology control, Fe-based bimetallic oxides with 3D morphology were developed in this study, which could effectively enhance the catalytic activity and inhibit the dissolution of metal ions, providing the design ideas for the construction of efficient catalysts and the removal of complex organic pollutants.

Novel cross-linkable fluorescent probe with oriented antibody to enhance lateral immunoassay strip for the detection of acetamiprid.

Time-resolved fluorescent lateral immunoassay strip (TRFLIS) is a reliable and rapid method for detecting acetamiprid. However, its sensitivity is often affected by the structural patterns and stability of the fluorescent probe. Researchers have shown significant interests in using goat anti-mouse IgG (GaMIgG) which is indirectly bound to time-resolved fluorescent microsphere (TRFM) and antibody. This allowed for oriented modification of the antibody. However, the stability of fluorescent probe in this binding mode remained unexplored. Herein, 1-ethyl-(3-dimethylaminopropyl) carbodiimide hydrochloride was innovatively used as a cross-linking agent to enhance the binding of antibody to GaMIgG, which improved the stability of the fluorescent probe. Under optimal working conditions, this strategy exhibited a wide linear response range of 5-700 ng/mL. Its limit of detection (LOD) was 0.62 ng/mL, the visual LOD was 5 ng/mL, and the limit of quantification (LOQ) of 2.06 ng/mL. Additionally, under tomato matrix, leek matrix and Chinese cabbage matrix, the linear response ranges were 5-400, 5-300, and 5-700 ng/mL, with LODs of 0.16, 0.60, and 0.41 ng/mL, with LOQs of 0.53, 2.01 and 1.37 ng/mL, respectively. In conclusion, this strategy effectively reduced the dosage of acetamiprid antibody compared with TRFM directly linking acetamiprid antibody, and greatly increased the sensitivity of TRFLIS. Meanwhile, it demonstrated outstanding specificity and accuracy in acetamiprid detection and had been successfully applied to vegetable samples. This method enables rapid and accurate detection of large-volume samples by combining qualitative and quantitative methods. As such, it has great potential in the development of low-cost and high-performance immunochromatographic platforms.

Rare-Earth-Metal-Free Solid-State Fluorescent Carbonized-Polymer Microspheres for Unclonable Anti-Counterfeit Whispering-Gallery Emissions from Red to Near-Infrared Wavelengths.

Colloidal carbon dots (CDs) have garnered much attention as metal-free photoluminescent nanomaterials, yet creation of solid-state fluorescent (SSF) materials emitting in the deep red (DR) to near-infrared (NIR) range poses a significant challenge with practical implications. To address this challenge and to engineer photonic functionalities, a micro-resonator architecture is developed using carbonized polymer microspheres (CPMs), evolved from conventional colloidal nanodots. Gram-scale production of CPMs utilizes controlled microscopic phase separation facilitated by natural peptide cross-linking during hydrothermal processing. The resulting microstructure effectively suppresses aggregation-induced quenching (AIQ), enabling strong solid-state light emission. Both experimental and theoretical analysis support a role for extended π-conjugated polycyclic aromatic hydrocarbons (PAHs) trapped within these microstructures, which exhibit a progressive red shift in light absorption/emission toward the NIR range. Moreover, the highly spherical shape of CPMs endows them with innate photonic functionalities in combination with their intrinsic CD-based attributes. Harnessing their excitation wavelength-dependent photoluminescent (PL) property, a single CPM exhibits whispering-gallery modes (WGMs) that are emission-tunable from the DR to the NIR. This type of newly developed microresonator can serve as, for example, unclonable anti-counterfeiting labels. This innovative cross-cutting approach, combining photonics and chemistry, offers robust, bottom-up, built-in photonic functionality with diverse NIR applications.

Nitrogen-doped hollow carbon sphere composite Mn3O4 as an advanced host for lithium-sulfur battery.

As the most promising advanced energy storage system, lithium-sulfur batteries (LSBs) are highly favored by the researchers because of their advantages of high energy density (2500 W h kg-1), low cost and non-pollution. However, the low conductivity, volume expansion of sulfur, and shuttle effect are still the great hindrance to the practical application of LSBs. Herein, the above problems can be addressed through the following strategies: (1) Hollow carbon microspheres with high specific surface area were constructed as sulfur hosts to increase sulfur loading while also being able to enhance the physical adsorption of polysulfides; (2) the loading of Mn3O4 particles on the basis of hollow carbon microspheres facilitates the capture and adsorption of polysulfides; (3) the hollow carbon sphere structure as a conductive network can provide more pathways for rapid electrical/ionic transport and also accelerate electrolyte wetting. Moreover, the thinner shell of hollow carbon microsphere is conducive to ion diffusion and speed up the reaction rate. Thus, the NHCS/Mn3O4/S composites exhibit a high discharge specific capacity of 1010.3 mAh g-1 at first and still maintained a reversible capacity of 269.2 mAh g-1 after 500 cycles. This work presents a facile sustainable and efficient synergistic strategy for the development of advanced LSBs.

Effect of mPEG-PLGA on Drug Crystallinity and Release of Long-Acting Injection Microspheres: In Vitro and In Vivo Perspectives.

PURPOSE: Traditional progesterone (PRG) injections require long-term administration, leading to poor patient compliance. The emergence of long-acting injectable microspheres extends the release period to several days or even months. However, these microspheres often face challenges such as burst release and incomplete drug release. This study aims to regulate drug release by altering the crystallinity of the drug during the release process from the microspheres. METHODS: This research incorporates methoxy poly(ethylene glycol)-b-poly(lactide-co-glycolide) (mPEG-PLGA) into poly(lactide-co-glycolide) (PLGA) microspheres to enhance their hydrophilicity, thus regulating the release rate and drug morphology during release. This modification aims to address the issues of burst and incomplete release in traditional PLGA microspheres. PRG was used as the model drug. PRG/mPEG-PLGA/PLGA microspheres (PmPPMs) were prepared via an emulsification-solvent evaporation method. Scanning electron microscopy (SEM), powder X-ray diffraction (PXRD), and differential scanning calorimetry (DSC) were employed to investigate the presence of PRG in PmPPMs and its physical state changes during release. RESULTS: The addition of mPEG-PLGA altered the crystallinity of the drug within the microspheres at different release stages. The crystallinity correlated positively with the amount of mPEG-PLGA incorporated; the greater the amount, the faster the drug release from the formulation. The bioavailability and muscular irritation of the long-acting injectable were assessed through pharmacokinetic and muscle irritation studies in Sprague-Dawley (SD) rats. The results indicated that PmPPMs containing mPEG-PLGA achieved low burst release and sustained release over 7 days, with minimal irritation and self-healing within this period. PmPPMs with 5% mPEG-PLGA showed a relative bioavailability (Frel) of 146.88%. IN CONCLUSION: In summary, adding an appropriate amount of mPEG to PLGA microspheres can alter the drug release process and enhance bioavailability.

Sequential diethylaminoethyl dextran-grafting and diethylaminoethyl modification improve the adsorption performance of anion exchangers.

Ion exchangers with high adsorption capacity, fast mass transfer, and high salt-tolerance synchronously are highly desired for high-performance protein purification. Here, we propose a sequential diethylaminoethyl dextran-grafting and diethylaminoethyl chloride modification strategy to achieve high-performance anion exchangers. The advantages of the double-modification strategy lie in: (1) the introduction of diethylaminoethyl in the second modification has no diffusion limitation due to the small molecular size, thus a high ionic capacity; (2) the grafting ligands not only provide three-dimensional adsorption space for high adsorption capacitybut alsofacilitate surface diffusion of protein by chain delivery. The maximum adsorption capacity of the obtained anion exchangers for bovine serum albumin reaches 333 mg/mL, the ratio of effective pore diffusivity (De) to free solution diffusivity (D0) reaches 0.69, and the adsorption amount reaches 97 mg/mL even in 100 mmol/L NaCl concentration,. All these results demonstrate the proposed sequential modification strategy are promising for the preparation of high-performance ion exchangers.

Microneedle delivery system with rapid dissolution and sustained release of bleomycin for the treatment of hemangiomas.

Hemangioma of infancy is the most common vascular tumor during infancy and childhood. Despite the proven efficacy of propranolol treatment, certain patients still encounter resistance or face recurrence. The need for frequent daily medication also poses challenges to patient adherence. Bleomycin (BLM) has demonstrated effectiveness against vascular anomalies, yet its use is limited by dose-related complications. Addressing this, this study proposes a novel approach for treating hemangiomas using BLM-loaded hyaluronic acid (HA)-based microneedle (MN) patches. BLM is encapsulated during the synthesis of polylactic acid (PLA) microspheres (MPs). The successful preparation of PLA MPs and MN patches is confirmed through scanning electron microscopy (SEM) images. The HA microneedles dissolve rapidly upon skin insertion, releasing BLM@PLA MPs. These MPs gradually degrade within 28 days, providing a sustained release of BLM. Comprehensive safety assessments, including cell viability, hemolysis ratio, and intradermal reactions in rabbits, validate the safety of MN patches. The BLM@PLA-MNs exhibit an effective inhibitory efficiency against hemangioma formation in a murine hemangioma model. Of significant importance, RNA-seq analysis reveals that BLM@PLA-MNs exert their inhibitory effect on hemangiomas by regulating the P53 pathway. In summary, BLM@PLA-MNs emerge as a promising clinical candidate for the effective treatment of hemangiomas.

Recent Advances in and Application of Fluorescent Microspheres for Multiple Nucleic Acid Detection.

Traditional single nucleic acid assays can only detect one target while multiple nucleic acid assays can detect multiple targets simultaneously, providing comprehensive and accurate information. Fluorescent microspheres in multiplexed nucleic acid detection offer high sensitivity, specificity, multiplexing, flexibility, and scalability advantages, enabling precise, real-time results and supporting clinical diagnosis and research. However, multiplexed assays face challenges like complexity, costs, and sample handling issues. The review explores the recent advancements and applications of fluorescent microspheres in multiple nucleic acid detection. It discusses the versatility of fluorescent microspheres in various fields, such as disease diagnosis, drug screening, and personalized medicine. The review highlights the possibility of adjusting the performance of fluorescent microspheres by modifying concentrations and carrier forms, allowing for tailored applications. It emphasizes the potential of fluorescent microsphere technology in revolutionizing nucleic acid detection and advancing health, disease treatment, and medical research.

Micron-Sized Thiol-Functional Polysilsesquioxane Microspheres with Open and Interconnected Macropores: Effects of the System Composition on the Porous Structure and Particle Size of the Microspheres.

Control of the porous structure and particle size is essential for improving the properties of polysilsesquioxane (PSQ) microspheres. Herein, using the strategy combining inverse suspension polymerization, two-step sol-gel- and polymerization-induced phase separation processes, micron-sized thiol-containing macroporous PSQ (TMPSQ) microspheres with controllable morphologies, adjustable particle diameters (4.9-17.3 µm), and pore sizes (40-3774 nm) were prepared. The morphology and size of the TMPSQ microspheres were characterized by SEM. The mercury intrusion method was employed to analyze the porous structure of the microspheres. The effects of the composition of the sol-gel disperse phase, the mass ratio of the sol-gel disperse phase to the oil continuous phase (WRW/O), and the Span 80 mass content in the oil continuous phase on the morphology, particle diameter and pore size of the TMPSQ microspheres were investigated. Results indicated that the composition of the sol-gel disperse phase determines the morphology and porous structure of the microspheres, and WRW/O and Span 80 content have remarkable impacts on the morphology and particle size of the microspheres. This study is beneficial to the design and fabrication of functional PSQ microspheres with desired properties and promising application prospects.

Harnessing three-dimensional porous chitosan microsphere embedded with adipose-derived stem cells to promote nerve regeneration.

BACKGROUND: Nerve guide conduits are a promising strategy for reconstructing peripheral nerve defects. Improving the survival rate of seed cells in nerve conduits is still a challenge and microcarriers are an excellent three-dimensional (3D) culture scaffold. Here, we investigate the effect of the 3D culture of microcarriers on the biological characteristics of adipose mesenchymal stem cells (ADSCs) and to evaluate the efficacy of chitosan nerve conduits filled with microcarriers loaded with ADSCs in repairing nerve defects. METHODS: In vitro, we prepared porous chitosan microspheres by a modified emulsion cross-linking method for loading ADSCs and evaluated the growth status and function of ADSCs. In vivo, ADSCs-loaded microcarriers were injected into chitosan nerve conduits to repair a 12 mm sciatic nerve defect in rats. RESULTS: Compared to the conventional two-dimensional (2D) culture, the prepared microcarriers were more conducive to the proliferation, migration, and secretion of trophic factors of ADSCs. In addition, gait analysis, neuro-electrophysiology, and histological evaluation of nerves and muscles showed that the ADSC microcarrier-loaded nerve conduits were more effective in improving nerve regeneration. CONCLUSIONS: The ADSCs-loaded chitosan porous microcarrier prepared in this study has a high cell engraftment rate and good potential for peripheral nerve repair.

High-efficient depletion and separation of histidine-rich proteins via Cu2+-chelated porous polymer microspheres.

Depletion and separation of histidine-rich proteins from complicated biosamples are crucial for various downstream applications in proteome research and clinical diagnosis. Herein, porous polymer microspheres coated with polyacrylic acid (SPSDVB-PAA) were fabricated through double emulsion interfacial polymerization technique and followed by immobilization of Cu2+ ions on the surface of SPSDVB-PAA. The as-prepared SPSDVB-PAA-Cu with uniform size and nanoscale pore structure enabled coordination interaction of Cu2+ with histidine residues in his-rich proteins, resulting in high-performance adsorption. As metal affinity adsorbent, the SPSDVB-PAA-Cu exhibited favorable selectivity for adsorbing hemoglobin (Hb) and human serum albumin (HSA) with the maximum adsorption capacities of 152.2 and 100.7 mg g-1. Furthermore, the polymer microspheres were used to isolate histidine-rich proteins from human whole blood and plasma, underscoring their effectiveness. The liquid chromatography tandem mass spectrometry (LC-MS/MS) results indicated that the content of 14 most abundant proteins in human plasma was depleted from 81.6 % to 30.7 % and low-abundance proteins were enriched from 18.4 % to 69.3 % after treatment with SPSDVB-PAA-Cu, illustrating potential application of SPSDVB-PAA-Cu in proteomic research.

Nanofabrication of Losartan Potassium Sustained Release Floating Microspheres Using Different Grades of Ethyl Cellulose and Its Insight on Release Profiles.

INTRODUCTION: A sustained release system for losartan potassium designed to delay its residence time in the stomach through the preparation of solvent evaporation technique-based floating microspheres. The influence of the different grades of Ethocel™ such as 4 cps, 10 cps, and 22 cps as well as the drug: polymer ratio on various properties of microspheres were tested. METHODS: Thermal and functional analysis revealed no interaction between the encapsulated drug and polymer. The results indicated that the mean diameter of microspheres increased with a change in grades of ethyl cellulose relating to viscosity. However, the drug incorporation efficiency within ethyl cellulose microspheres decreased with increasing viscosity of ethyl cellulose. RESULTS: The bulk density of the formulations was proportionally dependent on concentration and the viscosity of the polymer, which resulted in a decrease in floating capacity from 90.02% to 73.58%. Moreover, the drug release was indirectly proportional to the viscosity of ethyl cellulose tested. The in vitro release profile exhibited a burst effect with a biphasic release pattern following Fickian diffusion, indicating a diffusioncontrolled release mechanism. CONCLUSION: The results demonstrated that the viscosity of ethyl cellulose significantly affects the floating capacity and drug release pattern from microspheres.

Colorimetric detection of diamine using diamine oxidase and horseradish peroxidase co-incorporated hybrid microsphere as biomimetic cascade enzymes.

Dual-enzyme co-embedded materials have shown high potential for achieving efficient detection due to the convenience of two-enzyme cascade reactions. Herein, we developed a dual-enzyme hybrid microsphere (HM) based biosensor to detect diamines (histamine was included for ease of description) in aquatic products. The HM was made from diamine oxidase, horseradish peroxidase, and copper phosphate through the biomineralization method. Under optimal conditions, the system displayed linear color response to histamine of different concentrations ranging from 0 to 200 µg/mL. The detection limit of histamine was 0.15 µg/mL, showing higher sensitivity than the two-step free enzyme assay. Moreover, the detection system exhibited good specificity to diamines. The method was used to detect diamines in commercial samples, and the results were compared with those measured by the high-performance liquid chromatography method. Overall, the proposed assay exhibited high potential in diamine quantification and was readily extended to other cascade enzymatic reaction-based detection strategies.

A novel cell source for therapy of knee osteoarthritis using atelocollagen microsphere-adhered adipose-derived stem cells: Impact of synovial fluid exposure on cell activity.

Introduction: Administration of adipose-derived stem cells (ADSCs) into the joint cavity has been shown to alleviate the symptoms of knee osteoarthritis (OA) by releasing exosomes and anti-inflammatory cytokines. However, the therapeutic effect of these cells is limited by their rapid disappearance after administration. Thus, it is necessary to prolong cell survival in the joint cavity. This study aimed to investigate the potential application of ADSCs adhered to atelocollagen microspheres (AMSs) for cell therapy of knee OA. Methods: ADSCs were cultured for 2, 4, and 7 days in AMS suspension or adherent culture dishes. The supernatants were analyzed for IL-10 and exosome secretion via enzyme-linked immunosorbent assay and Nanosight. The effect of AMS was compared with that of adherent-cultured ADSCs (2D-cultured ADSCs) using transcriptome analysis. Moreover, the solubility of AMS and viability of ADSCs were evaluated using synovial fluid (SF) from patients with knee OA. Results: Compared with 2D-cultured ADSCs, AMS-cultured ADSCs exhibited a significant increase in secretion of exosomes and IL-10, and the expression of several genes involved in extracellular matrix and immune regulation were altered. Furthermore, when AMS-cultured ADSCs were cultured in SF from knee OA patients to mimic the intra-articular environment, the SF dissolved the AMSs and released viable ADSCs. In addition, AMS-cultured ADSCs showed significantly higher long-term cell viability than 2D-cultured ADSCs. Conclusion: Increased survival of AMS-adhered ADSCs was observed in the intra-articular environment, and AMSs were found to gradually dissipate. These results suggest that AMS-adhered ADSCs are promising source for cell therapy of knee OA.

A new sustainable filtration membrane extraction method based on nanoconfined liquid phase extraction: Determination of organochlorinated pesticides and pyrethroids in tea samples.

BACKGROUND: Pesticides are used in agricultural production for prevent and control crop diseases and pests, but it is easy to cause excessive pesticides residues in agricultural products, polluting the environment and endangering human health. Due to their unmatched and sustainable capabilities, nanoextraction procedures are becoming every day more important in Analytical Chemistry. In particular, nanoconfined liquid phase extraction has shown extraction capabilities toward polar, medium polar, and/or nonpolar substances, which can be easily modulated depending on the nanoconfined solvent used. Furthermore, this "green" technique showed excellent characteristics in terms of recoveries, extraction time (≤1 min), reliability, and versatility. (97) RESULTS: In this work, the advantages of this technique have been coupled with those of filtration membrane extraction, making use of carbon nanofibers (CnFs) growth on carbon microspheres (CµS). This substrate has been deposited on a filter, which combined with gas chromatographic mass spectrometry (GC-MS) analysis successfully employed for the nanoextraction of 30 pesticides (18 organochlorine and 12 pyrethroids) in tea samples. Under the optimized extraction conditions, the linear range with standard solutions was from 1 to 1000 ng mL-1 (R2 ≥ 0.99), the limit of detections in tea samples were in the range 0.56-17.98 µg kg-1. The accuracy of the developed method was evaluated by measuring the extraction recovery of the spiked tea samples, and recoveries between 74.41 % and 115.46 %. (119) SIGNIFICANCE: Considering the versatility of nanoconfined liquid phase extraction and the functionality of the filtration membrane extraction procedure, this new extraction method can be considered a powerful candidate for automatized high-throughput analyses of real samples. (34).

Diagnosis of neuropsychiatric systemic lupus erythematosus by label-free serum microsphere-coupled SERS fingerprints with machine learning.

Surface-enhanced Raman spectroscopy (SERS) is a powerful optical technique for non-invasive and label-free bioanalysis of liquid biopsy, facilitating to diagnosis of potential diseases. Neuropsychiatric systemic lupus erythematosus (NPSLE) is one of the subgroups of systemic lupus erythematosus (SLE) with serious manifestations for a high mortality rate. Unfortunately, lack of well-established gold standards results in the clinical diagnosis of NPSLE being a challenge so far. Here we develop a novel Raman fingerprinting machine learning (ML-) assisted diagnostic method. The microsphere-coupled SERS (McSERS) substrates are employed to acquire Raman spectra for analysis via convolutional neural network (CNN). The McSERS substrates demonstrate better performance to distinguish the Raman spectra from serums between SLE and NPSLE, attributed to the boosted signal-to-noise ratio of Raman intensities due to the multiple optical regulation in microspheres and AuNPs. Eight statistically-significant (p-value <0.05) Raman shifts are identified, for the first time, as the characteristic spectral markers. The classification model established by CNN algorithm demonstrates 95.0% in accuracy, 95.9% in sensitivity, and 93.5% in specificity for NPSLE diagnosis. The present work paves a new way achieving clinical label-free serum diagnosis of rheumatic diseases by enhanced Raman fingerprints with machine learning.