APL Bioengineering最新文献

Graphene is a 2D material that has emerged as a versatile and advanced material for biosensing technology due to its large surface area, high conductivity, and biocompatibility. These properties make it well-suited for label-free detection of biomarkers with high sensitivity and accuracy, which is crucial for early diagnosis of various diseases, environmental monitoring, and food safety. This review highlights recent progress in graphene-based biosensor technologies, emphasizing key fabrication methods such as mechanical exfoliation, liquid phase exfoliation, chemical vapor deposition, electrochemical exfoliation, and microwave-assisted exfoliation, which are highly effective and suitable for generating graphene at an industry level. Furthermore, the study highlights characterization techniques such as Raman spectroscopy, optical spectroscopy, scanning electron microscope, transmission electron microscopy, and atomic force microscopy, which ensure quality and functionality of the graphene in biosensing applications. While hurdles like enhancing conductivity and achieving large-scale production remain, graphene-based biosensors offer a transformative approach to delivering precise and consistent results across various industries, paving the way for innovative solutions in diagnostics and monitoring systems.

Diagnosis of a glioblastoma (GBM) brain tumor is associated with very poor prognosis. Currently, few preclinical models used to identify new therapies address the soft brain tissue environment and GBM mechanoresponses, which are implicated in disease progression. Understanding the GBM biomechanical landscape is critical to deriving improved preclinical models and magnetic resonance elastography (MRE) holds promise to address this gap. Due to technical and feasibility issues for MRE of patient tumors at scale, most studies only report on small cohorts of patients, thus limiting the conclusions that may be drawn from individual studies. To thus gain a better overview, we have undertaken a systematic review and meta-analysis of the reported tissue viscoelastic property values from studies of both healthy brain and brain tumors, with a particular focus on delineating measurements relative to MRE transducer vibration frequency. Based on these analyses, healthy white matter consistently appears stiffer than gray matter. Further, analyses of pooled healthy brain tissue measurements vs human GBM suggested that, overall, the GBM has the same stiffness as the surrounding healthy tissue. This contrasted with mouse models of GBM, where the tumors appear softer than brain tissue. The limited number of studies of human GBM in situ is a caveat to these conclusions and MRE analyses of larger GBM patient cohorts are urgently needed. Meanwhile, the information from this analysis can be used to guide engineering of improved preclinical models with features that recapitulate the in vivo brain tissue environment.

Animal models, especially rodents, used to study neurodevelopment have significantly advanced our comprehension of cellular and molecular mechanisms. Nevertheless, differences in species-specific structures, gestation periods, and interneuronal connections limit animal models' ability to represent human neurodevelopment accurately. The unique characteristics of primate neural progenitor cells (NPCs) enable cortex expansion with gyrus formation, which does not occur in lissencephalic animals, like rodents. Therefore, there is a need for novel in vitro models using human cells that recapitulate the complexity of human brain development. Along with organoids, 3D bioprinting offers a platform for creating more complex in vitro models. We developed, extensively characterized, and successfully used a Geltrex™/GelMA hydrogel blend to bioprint human induced pluripotent stem cells-derived NPCs (hNPCs). We show that 3D bioprinted hNPCs can self-organize, revealing key features of a neurogenic niche, including proliferation, differentiation, and migration, remaining viable for over 110 days. Within the first 20 days, bioprinted constructs showed the formation of positive cell clusters for the neurogenic niche cell markers FABP7, NESTIN, and GFAP. Clusters were interconnected by process bundles supporting cell migration. The cells proliferated within the clusters, and over time, NPCs originated TUBB3⁺ neurons with long axonal tracts, prominent around the clusters. We propose this as a 4D model to study neurogenic niches' key cellular and molecular features in a 3D bioprinted scaffold, adding time as the fourth dimension. Neuronal maturation in this dynamic model recapitulates key neurogenic niche properties, making it suitable for neurodevelopmental disease modeling and drug screening.

Ankylosing spondylitis (AS), characterized by inflammation of sacroiliac joints and spinal attachments, has an unclear pathogenesis. This study aims to screen and authenticate immune cell-associated biomarkers in AS. Two Gene Expression Omnibus datasets (GSE25101 and GSE41038) were combined as the discovery dataset, with candidate biomarkers screened via differential expression analysis, immune cell infiltration analysis, and weighted gene co-expression network analysis (WGCNA). Immune cell-related biomarkers were further identified and validated by receiver operating characteristic (ROC) analysis using the confirmatory dataset GSE73754, and potential diagnostic biomarkers were finally confirmed by reverse transcription quantitative polymerase chain reaction (RT-qPCR), immunofluorescence staining, and single-cell RNA sequencing (scRNA-seq) analysis (GSE194315). Thirty-two differentially expressed genes between the AS and control samples were identified. The ratio of M2 macrophages was significantly different between the AS and control samples. Seven candidate biomarkers associated with immune cells in AS were identified by WGCNA and Venn diagram. Then, three genes (SBK1, HNRPR, and CX3CR1) were authenticated as immune cell-associated biomarkers in AS by ROC curves, indicating a possible diagnostic value in clinical settings. The results of RT-qPCR, immunofluorescence staining, and scRNA-seq analysis all confirmed that CX3CR1 was down-regulated in AS, which was in line with bioinformatics study findings. Dysregulation of the CX3CR1 and M2-type macrophage ratio are key factors in AS, which lay the groundwork for exploring illness pathophysiology and yielding fresh perspectives on AS diagnosis and therapy.

Extracellular vesicles (EVs), secreted by most living cells, encapsulate a diverse array of bioactive molecules from their parent cells, including proteins and nucleic acids. Recent studies underscore the potential of EVs as advanced biomarkers for the early diagnosis of a variety of clinical diseases. Nevertheless, traditional platforms for EVs separation and detection platforms working alone often involve multiple pieces of equipment and complex, multi-step protocols. This extends processing time and the likelihood of bioanalyte loss and cross-contamination, thereby impeding further EVs research. To date, few studies have effectively combined EVs separation, detection, and analysis functions into a single platform. Integrated microfluidic platforms present a compelling solution by enabling seamless progression from sample to result. These platforms can efficiently combine various separation and detection techniques, simplifying complex workflows and facilitating both efficient EVs separation and high-sensitivity detection. This review concentrates on integrated microfluidic platforms for EVs separation and detection, specifically examining whether the separation and detection units are fully integrated. Recent studies underscore the potential of EVs as promising biomarkers for early-stage diagnosis of diseases, including cancer and neurodegenerative disorders. Recent advances in EVs separation and analysis enable overcoming key translational barriers, accelerating their routine adoption in clinical diagnostics.

A fully implantable sensorized organ to replace the natural urinary bladder holds considerable promise for patients undergoing radical cystectomy. Clinical options to restore continence include urine redirection to wearable bags or reconstruction of neobladders from autologous tissues, often with limited capacity. However, none of these approaches can restore patient's ability to perceive bladder fullness, making voiding self-management complex and burdensome. To address these limitations, we introduce the Soft Self-Sensitive Artificial Bladder (S3AB), a fully implantable sensorized organ designed to replace urinary bladder anatomy, as well as continence and fullness monitoring. The S3AB main component is a silicone origami-inspired bladder designed to fit the abdominopelvic cavity. The foldable and soft nature facilitates the maintenance of intravesical pressure below the physiological range, thereby promoting the preservation of renal function over time. The bladder is integrated with a multi-sensor system based on resistive textile sensors featuring durability and functionality throughout repetitive cycles of filling and draining. The sensors demonstrate stability at physiological temperatures. Once isolated from bodily fluids, textile sensors permit to monitor the bladder internal volume leveraging on the origami structure opening during filling, with an estimation accuracy within approximately 12%. Volume monitoring allows warning the patient when the maximum capacity is almost reached, thus making possible a natural micturition management. S3AB proved efficient in restoring urine collection and filling state monitoring upon successful implantation in a large animal model.

The achievement of pathological complete response (pCR) with neoadjuvant therapy can significantly improve prognosis in patients with gastric cancer (GC). GC tissues demonstrating pCR after immunotherapy exhibited increased stiffness and proliferation of fibroblasts within the stroma. Specific subpopulation cancer-associated fibroblasts (CAFs) may serve as potential markers for predicting the efficacy of immunotherapy. We screened CAFs-related genes as candidate predictors for immunotherapy using the TCGA-STAD, PRJEB25780, GSE27342, and GSE54129 databases. Tissue specimen from GC patients enrolled in the clinical trial (NCT04208347) was used to evaluate its clinical significance. Single-cell RNA sequencing (scRNA-seq) data were obtained from GSE163558, GSE183904, and GSE184198 datasets and analyzed through Seurat v3 R software and iTALK. GC patient-derived organoids (GC-PDOs) modeling verified the effect of CAFs subpopulations on immunotherapeutic response in vitro. Podoplanin (PDPN) has been identified as a candidate marker related to CAFs for predicting the efficacy of immunotherapy. Western blot analysis indicated that lower PDPN expression was observed in GC samples with pCR. Functional and pathway enrichment analysis indicated PDPN was associated with numerous malignancy-related pathways in gastric cancer. Using the iTALK algorithm, scRNA-seq datasets further verified the interaction between a subpopulation of PDPN+ CAFs and immune cells. The results of multiple immunohistochemistry/immunofluorescence suggested a negative correlation between PDPN+ CAFs and pCR to anti-PD-1 treatment (p < 0.01). Notably, using the GC-PDO model, we determined that PDPN + CAFs hinder the activation, thereby reducing immune response in GC patients. PDPN+ CAFs subpopulation has a potential correlation with the efficacy of immunotherapy for GC patients.

Despite the effects of shear stress on endothelial biology having been extensively researched, the effects of hydrostatic vascular pressure at extremely low shear stresses have been largely ignored. In the current study, we employ a microfluidic organ-on-chip platform to elucidate the time and shear stress dependent effects of elevated hydrostatic pressure on endothelial junctional perturbations. We report that short term (1 h) exposure to elevated hydrostatic pressure at high shear stress (0.1 Pa) but not low shear stress (0.01 Pa) caused VE-cadherin to form finger like projections at the cell-cell junctions, and this effect was abrogated upon pharmacologically inhibiting cationic mechanosensitive channels using GsMTx4 peptide. Interestingly, prolonged exposure (24 h) to elevated hydrostatic pressure at low (0.01 Pa) but not high shear stress (0.1 Pa) caused disruption of VE-cadherin at cell-cell contacts and increased its cytoplasmic concentration. Furthermore, we report that this disruption of VE-cadherin was reversible upon pharmacologically inhibiting cationic mechanosensitive channels in a time-dependent manner; wherein after 12 h, we observed VE-cadherin reassemble at the cell-cell junctions. Overall, we demonstrate that cationic mechanosensitive channels play a crucial role in the mechanotransduction of elevated hydrostatic pressure by regulating the VE-cadherin dynamics at cell-cell junctions.

Damage to the olfactory nerve, caused by aging, trauma, or neurological disorders, can lead to smell loss, negatively impacting quality of life, taste perception, safety, and emotional well-being. Currently, olfactory training, which involves exposure to aromatic odorants, is the most widely used treatment. While this method provides some benefit, it does not offer a fundamental cure. Developing an approach that directly stimulates the olfactory nerves to restore neural activity is critical for effectively addressing smell loss. This study investigates the effects of radiofrequency (RF) stimulation on the olfactory nerves in healthy individuals to evaluate its potential as a treatment for olfactory dysfunction. An RF antenna was positioned, and the specific absorption rate was verified using 3D modeling. The sensitivity of odor threshold tests with n-butanol and specific odors was assessed in a total of 28 healthy subjects, confirming olfactory nerve stimulation through electrobulbogram measurements. The average odor threshold for n-butanol in 23 subjects was 9.73 ± 2.45. RF stimulation on the olfactory nerve for 5 min at 10-20 W improved the odor threshold score to 15.88 ± 0.25, indicating enhanced sensitivity lasting up to one week. Electrical signals from olfactory nerves significantly increased after RF stimulation compared to pre-stimulation levels, consistent with results for natural odors like grapes and bananas. Unlike chemical-based treatments, RF stimulation avoids discomfort or dissipation of effects and provides sustained nerve activation. These findings demonstrate the potential of RF technology for olfactory training and as a novel treatment for olfactory dysfunction, as well as applications in maintaining odor sensitivity for professionals.

3D cell spheroids have become crucial in vitro models for biomedical research, yet maintaining their growth and viability remains challenging due to diffusion limitations. We developed a versatile microfluidic modular device with a reconfigurable channel design that is customizable by altering the channel configuration in the adhesive layer. The resealable adhesive layer also enables open access to the wells for loading cells, continuous perfusion after closing, and facile retrieval of spheroids for downstream analysis and imaging after culturing. We evaluated three channel configurations using Mouse Embryonic Fibroblasts (MEFs), human induced Pluripotent Stem Cells (hiPSCs), and MDA-MB-231 breast cancer cells. The device significantly improved spheroid growth in MEFs and hiPSCs, increasing up to 139.9% over controls in 14 days. In contrast, MDA-MB-231 spheroids exhibited slower growth, highlighting the need for balancing nutrient delivery with autocrine factor retention. Sphericity was maintained in MEF and MDA-MB-231 spheroids, while hiPSC spheroids experienced budding. In situ optical coherence tomography (OCT) provided noninvasive 3D viability assessments of the spheroids. Our findings demonstrate that this modular microfluidic device, combined with OCT analysis, offers a powerful platform for advancing spheroid culture techniques and opens up new opportunities in applications such as drug testing, studying spheroid-spheroid interactions, and collecting spheroid secretions.