Evaluation of Pm2.5 Influence on Human Lung Cancer Cells Using a Microfluidic Platform.

In this study, we developed a microfluidic device that is able to monitor cell biology under continuous PM2.5 treatment. The effects of PM2.5 on human alveolar basal epithelial cells, A549 cells, and uncovered several significant findings were investigated. The results showed that PM2.5 exposure did not lead to a notable decrease in cell viability, indicating that PM2.5 did not cause cellular injury or death. However, the study found that PM2.5 exposure increased the invasion and migration abilities of A549 cells, suggesting that PM2.5 might promote cell invasiveness. Results of RNA sequencing revealed 423 genes that displayed significant differential expression in response to PM2.5 exposure, with a particular focus on pathways associated with the generation of reactive oxygen species (ROS) and mitochondrial dysfunction. Real-time detection demonstrated an increase in ROS production in A549 cells after exposure to PM2.5. JC1 assay, which indicated a loss of mitochondrial membrane potential (ΔΨm) in A549 cells exposed to PM2.5. The disruption of mitochondrial membrane potential further supports the detrimental effects of PM2.5 on A549 cells. These findings highlight several adverse effects of PM2.5 on A549 cells, including enhanced invasion and migration capabilities, altered gene expression related to ROS pathways, increased ROS production and disruption of mitochondrial membrane potential. These findings contribute to our understanding of the potential mechanisms through which PM2.5 can impact cellular function and health.

Cold atmospheric plasma-enabled platelet vesicle incorporated iron oxide nano-propellers for thrombolysis.

A new approach to treating vascular blockages has been developed to overcome the limitations of current thrombolytic therapies. This approach involves biosafety and multimodal plasma-derived theranostic platelet vesicle incorporating iron oxide constructed nano-propellers platformed technology that possesses fluorescent and magnetic features and manifold thrombus targeting modes. The platform is capable of being guided and visualized remotely to specifically target thrombi, and it can be activated using near-infrared phototherapy along with an actuated magnet for magnetotherapy. In a murine model of thrombus lesion, this proposed multimodal approach showed an approximately 80 % reduction in thrombus residues. Moreover, the new strategy not only improves thrombolysis but also boosts the rate of lysis, making it a promising candidate for time-sensitive thrombolytic therapy.

A Biomimicking and Multiarm Self-Indicating Nanoassembly for Site-Specific Photothermal-Potentiated Thrombolysis Assessed in Microfluidic and In Vivo Models.

Thrombolytic and antithrombotic therapies are limited by short circulation time and the risk of off-target hemorrhage. Integrating a thrombus-homing strategy with photothermal therapy are proposed to address these limitations. Using glycol chitosan, polypyrrole, iron oxide and heparin, biomimicking GCPIH nanoparticles are developed for targeted thrombus delivery and thrombolysis. The nanoassembly achieves precise delivery of polypyrrole, exhibiting biocompatibility, selective accumulation at multiple thrombus sites, and enhanced thrombolysis through photothermal activation. To simulate targeted thrombolysis, a microfluidic model predicting thrombolysis dynamics in realistic pathological scenarios is designed. Human blood assessments validate the precise homing of GCPIH nanoparticles to activated thrombus microenvironments. Efficient near-infrared phototherapeutic effects are demonstrated at thrombus lesions under physiological flow conditions ex vivo. The combined investigations provide compelling evidence supporting the potential of GCPIH nanoparticles for effective thrombus therapy. The microfluidic model also offers a platform for advanced thrombolytic nanomedicine development.

Early committed polarization of intracellular tension in response to cell shape determines the osteogenic differentiation of mesenchymal stromal cells.

Within the heterogeneous tissue architecture, a comprehensive understanding of how cell shapes regulate cytoskeletal mechanics by adjusting focal adhesions (FAs) signals to correlate with the lineage commitment of mesenchymal stromal cells (MSCs) remains obscure. Here, via engineered extracellular matrices, we observed that the development of mature FAs, coupled with a symmetrical pattern of radial fiber bundles, appeared at the right-angle vertices in cells with square shape. While circular cells aligned the transverse fibers parallel to the cell edge, and moved them centripetally in a counter-clockwise direction, symmetrical bundles of radial fibers at the vertices of square cells disrupted the counter-clockwise swirling and bridged the transverse fibers to move centripetally. In square cells, the contractile force, generated by the myosin IIA-enriched transverse fibers, were concentrated and transmitted outwards along the symmetrical bundles of radial fibers, to the extracellular matrix through FAs, and thereby driving FA organization and maturation. The symmetrical radial fiber bundles concentrated the transverse fibers contractility inward to the linkage between the actin cytoskeleton and the nuclear envelope. The tauter cytoskeletal network adjusted the nuclear-actomyosin force balance to cause nuclear deformability and to increase nuclear translocation of the transcription co-activator YAP, which in turn modulated the switch in MSC commitment. Thus, FAs dynamically respond to geometric cues and remodel actin cytoskeletal network to re-distribute intracelluar tension towards the cell nucleus, and thereby controlling YAP mechanotransduction signaling in regulating MSC fate decision. STATEMENT OF SIGNIFICANCE: We decipher how cellular mechanics is self-organized depending on extracellular geometric features to correlate with mesenchymal stromal cell lineage commitment. In response to geometry constrains on cell morphology, symmetrical radial fiber bundles are assembled and clustered depending on the maturation state of focal adhesions and bridge with the transverse fibers, and thereby establishing the dynamic cytoskeletal network. Contractile force, generated by the myosin-IIA-enriched transverse fibers, is transmitted and dynamically drives the retrograde movement of the actin cytoskeletal network, which appropriately adjusts the nuclear-actomyosin force balance and deforms the cell nucleus for YAP mechano-transduction signaling in regulating mesenchymal stromal cell fate decision.

Glycol chitosan/iron oxide/polypyrrole nanoclusters for precise chemodynamic/photothermal synergistic therapy.

Noninvasive photothermal therapy (PTT) represents a promising direction for more modern and precise medical applications. However, PTT efficacy is still not satisfactory due to the existence of heat shock proteins (HSPs) and poorly targeted delivery. Herein, the design of a nanosystem with improved delivery efficacy for anticancer treatment employing the synergetic effects of reactive oxygen species (ROS)-driven chemodynamic therapy (CDT) to inactivated HSPs with photothermal-hyperthermia was therefore achieved through the development of pH-targeting glycol chitosan/iron oxide enclosed core polypyrrole nanoclusters (GCPI NCs). The designed NCs effectively accumulated toward cancer cells due to their acidic microenvironment, initiating ROS generation via Fenton reaction at the outset and performing site-specific near infrared (NIR)-photothermal effect. A comprehensive analysis of both surface and bulk material properties of the CDT/PTT NCs as well as biointerface properties were ascertained via numerous surface specific analytical techniques by bringing together heightened accumulation of CDT/PTT NCs, which can significantly eradicate cancer cells thus minimizing the side effects of conventional chemotherapies. All of these attributes act in synergy over the cancer cells succeeding in fashioning NC's able to act as competent agents in the MRI-monitored enhanced CDT/PTT synergistic therapy. Findings in this study evoke attention in future oncological therapeutic strategies.

Continuous polymerase chain reaction microfluidics integrated with a gold-capped nanoslit sensing chip for Epstein-Barr virus detection.

We present the first combination of a microfluidic polymerase chain reaction (PCR) with a gold nanoslit-based surface plasmon resonance (SPR) sensor for detecting the DNA sequence of latent membrane protein 1 (LMP1). The PCR microchannel was produced through a laser scribing technique, and the SPR nanoslit chip was manufactured via hot-embossing nanoimprinting lithography. Afterward, the LMP1 DNA probe was adsorbed onto the SPR chip of the integrated device through electrostatic interactions for further detection. The device can complete the analytical procedure in around 36 min, while the traditional machine requires 105 min to achieve similar signals under the same PCR thermal cycles. The calibration curve with serially diluted LMP1 DNA exhibited the accuracy (R2 > 0.99) and sensitivity (limit of detection: ∼10-11 g/mL) of the device. Moreover, extracted DNA from Epstein-Barr virus (EBV)-positive cells were directly detected through the integrated chip. In brief, this all-in-one chip can amplify gene fragments at the front-end and detect them at the back-end, decreasing the time required for the analysis without compromising accuracy or sensitivity. We believe this label-free, real-time, low-cost device has enormous potential for rapid detection of various viruses, such as EBV and COVID-19.

Peptide-based electrochemical sensor with nanogold enhancement for detecting rheumatoid arthritis.

Rheumatoid arthritis (RA), an autoimmune and chronic inflammatory disorder, is an incurable disease. We developed a peptide-based electrochemical sensor using electrochemical impedance spectroscopy that can be used to detect autoantibodies for RA diagnostics. We first validated that the developed peptide showed high sensitivity and could compliment the current gold standard method of an anti-cyclic citrullinated peptide antibody (anti-CCP) ELISA. The developed peptide can be modified on the nanogold surface of the working electrode of sensing chips through the method of a self-assembling monolayer. The sensing process was first optimized using a positive control cohort and a healthy control cohort. Subsequently, 10 clinically confirmed samples from RA patients and five healthy control samples were used to find the threshold value of the impedance between RA and healthy subjects. Furthermore, 10 clinically confirmed samples but with low values of anti-CCP autoantibodies were used to evaluate the sensitivity of the present method compared to the conventional method. The proposed method showed better sensitivity than the current conventional anti-CCP ELISA method.

Keratin-Based Nanoparticles with Tumor-Targeting and Cascade Catalytic Capabilities for the Combinational Oxidation Phototherapy of Breast Cancer.

Photodynamic therapy (PDT) holds tantalizing prospects of a prominent cancer treatment strategy. However, its efficacy remains limited by virtue of the hypoxic tumor microenvironment and the inadequate tumor-targeted delivery of photosensitizers, and these can be further exacerbated by the lack of development of a well-controlled nitric oxide (NO) release system at the target site. Inspired by Chinese medicine, we propose a revealing new keratin application. Keratin has garnered attention as an NO generator; however, its oncological use has rarely been investigated. We hypothesized that the incorporation of a phenylboronic acid (PBA) targeting ligand/methylene blue (MB) photosensitizer with a keratin NO donor would facilitate precise tumor delivery, enhancing PDT. Herein, we demonstrated that MB@keratin/PBA/d-α-tocopherol polyethylene glycol 1000 succinate (TPGS) nanoparticles (MB@KPTNPs) specifically targeted breast cancer cells and effectively suppressed their growth. Through MB-mediated biometabolism, the endocytic MB@KPTNPs produced a sufficient amount of intracellular NO that reduced the glutathione level while boosting the efficiency of PDT. A therapeutic combination of NO/PDT was therefore achieved, resulting in significant inhibition of both in vivo tumor growth and lung metastasis. These findings underscore the importance of utilizing keratin-based nanoparticles that simultaneously combine targeting of the tumor and self-generating NO with a cascading catalytic ability as a novel oxidation therapeutic strategy for enhancing PDT.

Dual-Targeting Glycol Chitosan/Heparin-Decorated Polypyrrole Nanoparticle for Augmented Photothermal Thrombolytic Therapy.

Near-infrared (NIR)-light-modulated photothermal thrombolysis has been investigated to overcome the hemorrhage danger posed by clinical clot-busting substances. A long-standing issue in thrombosis fibrinolytics is the lack of lesion-specific therapy, which should not be ignored. Herein, a novel thrombolysis therapy using photothermal disintegration of a fibrin clot was explored through dual-targeting glycol chitosan/heparin-decorated polypyrrole nanoparticles (GCS-PPY-H NPs) to enhance thrombus delivery and thrombolytic therapeutic efficacy. GCS-PPY-H NPs can target acidic/P-selectin high-expression inflammatory endothelial cells/thrombus sites for initiating lesion-site-specific thrombolysis by hyperthermia using NIR irradiation. A significant fibrin clot-clearance rate was achieved with thrombolysis using dual-targeting/modality photothermal clot disintegration in vivo. The molecular level mechanisms of the developed nanoformulations and interface properties were determined using multiple surface specific analytical techniques, such as particle size distribution, zeta potential, electron microscopy, Fourier-transform infrared spectroscopy (FTIR), wavelength absorbance, photothermal, immunofluorescence, and histology. Owing to the augmented thrombus delivery of GCS-PPY-H NPs and swift treatment time, dual-targeting photothermal clot disintegration as a systematic treatment using GCS-PPY-H NPs can be effectively applied in thrombolysis. This novel approach possesses a promising future for thrombolytic treatment.

Cell-Cell Adhesion-Driven Contact Guidance and Its Effect on Human Mesenchymal Stem Cell Differentiation.

Contact guidance has been extensively explored using patterned adhesion functionalities that predominantly mimic cell-matrix interactions. Whether contact guidance can also be driven by other types of interactions, such as cell-cell adhesion, still remains a question. Herein, this query is addressed by engineering a set of microstrip patterns of (i) cell-cell adhesion ligands and (ii) segregated cell-cell and cell-matrix ligands as a simple yet versatile set of platforms for the guidance of spreading, adhesion, and differentiation of mesenchymal stem cells. It was unprecedently found that micropatterns of cell-cell adhesion ligands can induce contact guidance. Surprisingly, it was found that patterns of alternating cell-matrix and cell-cell strips also induce contact guidance despite providing a spatial continuum for cell adhesion. This guidance is believed to be due to the difference between the potencies of the two adhesions. Furthermore, patterns that combine the two segregated adhesion functionalities were shown to induce more human mesenchymal stem cell osteogenic differentiation than monofunctional patterns. This work provides new insight into the functional crosstalk between cell-cell and cell-matrix adhesions and, overall, further highlights the ubiquitous impact of the biochemical anisotropy of the extracellular environment on cell function.

LMP1 gene detection using a capped gold nanowire array surface plasmon resonance sensor in a microfluidic chip.

Surface plasmon resonance (SPR) nanowire array chips with a microfluidic system are an effective detection method for a rapid test device. This study investigated a capped gold nanowire array and a microfluidic test platform to provide a fundamental understanding of the kinetic binding of SPR nanowires and the surface gold refractive index. The device sensitivity of the SPR nanowire array was 485 nm RIU-1 and the detection limit was 4.1 × 10-5 RIU. Moreover, a kinetic binding analysis also indicated that a peak shift resulted from a specific hybridization of the target molecule with the immobilized probe on the gold nanostructures. The peak shift (red-shift) value of latent membrane protein 1 (LMP1) DNA was 2.21 nm. The results demonstrated that this new method had high sensitivity to detect amplified DNA products without labeling or complex sample treatment. The SPR nanowire chip can detect the PCR products at lower cycle numbers compared to gel electrophoresis due to probe and DNA specificity. Furthermore, the mechanisms of SPR nanowire array fabrication and the detection of the LMP1 gene were studied. The findings can assist in improving the biosensing of DNA-amplified products and in developing rapid detection devices with a small-footprint nanostructured SPR chip.