Closed-loop control over bladder function, for conditions such as neurogenic bladder dysfunction, requires real-time monitoring of bladder state. Here, we assessed the ability of a novel recording and analysis technique to extract neural activity from awake rats as a quasi-real-time feedback biomarker of bladder fullness in normal and chronic cystitis models. Adult male rats (n = 12) were implanted with a four-electrode planar array and the bladder instrumented for continuous-flow cystometry over 2 weeks. In three rats, bladder inflammation was induced using cyclophosphamide (CYP, 75-100 mg/kg, i.p.). Neural recordings were made during awake cystometry, and extracted Aδ afferent activity was correlated with bladder pressure. In control rats (n = 9), there was a strong, stable correlation of integrated Aδ activity with bladder pressure during filling at 1 week (R 2: 0.55 ± 0.04) and 2 weeks (R 2: 0.57 ± 0.04; p > 0.05). In CYP-cystitis rats (days 9, 11, and 14), there was no difference in this correlation (week 2: 0.54 ± 0.031; p > 0.05). Taken together, data suggest the recording and analysis technology remained stable in awake, freely moving normal rats and during 2 weeks of chronic implantation. Furthermore, data show potential that abnormal activation of nociceptive afferents in cystitis rats, which causes an increase in baseline activity, does not weaken correlation of Aδ activity with bladder pressure. In conclusion, this feasibility study is a promising first study step for the translation of closed-loop technology for bladder control for neurogenic bladder dysfunction.
Currently, preclinical research on colorectal cancer (CRC) lacks effective tumor models. In recent years, 3D bioprinted models have shown great potential in tumor model construction. This study used 3D bioprinting technology to establish a CRC extracellular matrix (ECM) model. Gradient concentrations of laminin/entactin complex combined with photocurable gelatin methacrylate (GelMA) hydrogel were used to prepare 3D bioprinting bioinks with biomimetic ECM properties. Biocompatibility was assessed by calcein-AM and propidium iodide staining. Proliferation was evaluated using the CellTiter-Glo® Luminescent Cell Viability Assay Kit in SW620 cells and primary CRC cells. A “sandwich structure” model with inner and outer layers of GelMA or GelMA + LE2 was constructed to observe cell invasion. Mechanical properties of GelMA + LE2 were characterized. Total RNA was extracted from cells in 3D bioprinted models constructed with GelMA and GelMA + LE2 for transcriptome sequencing. Finally, chemotherapeutic drug tests were performed on the 3D bioprinted models. A 3D bioprinted CRC organoid model based on GelMA + LE2 was successfully established. This model exhibited good biocompatibility and the ability to promote tumor cell proliferation and invasion. These characteristics were independent of the model's mechanical properties. Instead, they originated from LE2 activating the ErbB/Wnt signaling pathway and gap junction-mediated intercellular communication. Additionally, a significant correlation was observed between the clinical treatment outcomes of CRC patients and the drug test results of the 3D bioprinted models. The 3D bioprinted CRC organoid constructed in this study provides a biomimetic and high-throughput research platform for precision medicine.
Endovascular coiling is a minimally invasive therapeutic option for intracranial aneurysm (IA). This technique involves occluding the aneurysmal sac with one or more metallic coils to decrease perfusion of the dilated arterial wall. Although coil deployment has proven to be generally effective, clinical outcomes are difficult to predict, with aneurysms reopening occurring in approximately 20% of cases. The purpose of this study is to use in silico modeling combined with statistical analysis and machine learning to predict the biomechanical outcomes of coiling by studying the relationship between IA morphology and post-coiling quantitative parameters. First, a clinical database of IAs was parametrized based on a set of geometrical features. and 500 synthetic sac geometries were virtually generated. Simulations of coil deployment were then performed for each of these geometries, and the resulting reaction force, elastic energy, and contact pressure were used to train a predictive machine learning algorithm. The surrogate model demonstrated strong predictive performance for the reaction force (R2 = 0.74 and MAPE = 4.56%) and moderate performance for the elastic energy stored by the deformed coil (R2 = 0.68 and MAPE = 26.95%). Morphological factors such as aneurysm sac volume, surface, and height showed a good correlation with simulation parameters using Spearman analysis. As a preliminary proof-of-concept study, this methodology represents a first step toward the development of an in silico tool aimed at enhancing pre-operative planning for endovascular coil procedures. This has the potential to improve the stratification of patients at higher risk of complications and the identification of borderline IAs that may not be suitable for endovascular coiling.
An important process in wound healing is re-epithelialization, wherein cells collectively migrate to cover the wounded area. Here, we investigate how cellular forces lead to the migration of an epithelial monolayer in a wound healing assay. We report that heparin-bound epidermal growth factor (HB-EGF) increased the rate of collective migration in a phospholipase C-dependent manner through a combination of increased cell speed and straighter, more coordinated motion. Using traction force microscopy, we found that HB-EGF increased the forces within the cell monolayer, producing a competition between elevated traction at the edge of the monolayer and elevated stress within the bulk of the monolayer. To investigate how this interplay led to faster monolayer migration, we used a theoretical model for collective cell migration, which, when compared against the experimental data, suggested faster migration resulted from increased active propulsive forces at both the leading edge and within the bulk of the cell monolayer. Experimental analysis of actin stress fibers and vinculin foci supported inferences made from the model. Combined, our results support that HB-EGF induced a greater magnitude of traction for cells at the edge of the monolayer and aligned the direction of traction for cells within the bulk, thereby leading to faster and more persistent collective migration.
Three-dimensional (3D) multicellular ex vivo cultures have become central tools for cancer research and drug testing under physiologically relevant conditions. Organ-on-a-chip technologies based on microfluidics provide platforms for culturing and analyzing 3D tissues under flow. However, maintaining long-term continuous perfusion typically requires pumps and complex tubing networks, increasing operational complexity, cost, and limiting scalability for routine use. Pumpless approaches have been explored but often suffer from short flow duration, inconsistent unidirectional perfusion, and frequent reservoir replenishment. Here, we present a vertical pump-free fluidic platform designed for spheroid formation, culture, and biological testing. The system integrates molds for spheroid assembly with a modular 3D-printed culture chamber that allows direct sample access. A stackable cartridge-like design enables parallel assays under identical conditions, while the incorporation of commercially available syringes as structural elements improves standardization and reduces the footprint. Continuous perfusion over several days is achieved using a hydrogel-based flow resistor that generates passive pressure gradients. Using three human ovarian cancer cell lines (Ovcar-3, A2780, and Ovcar-8), we demonstrate the formation of uniform spheroids that maintain viability and metabolic activity for up to one week within the 3D-printed cartridges. Drug response was evaluated using paclitaxel, with measurable effects on spheroid growth and invasion. Flow simulations and experimental measurements confirm stable perfusion for approximately 3 days, followed by a gradual decline until cessation at day 7. Overall, this pump-free platform provides a scalable, modular solution for controlled 3D culture and multi-functional assays without external pumping systems.
Therapeutic ultrasound (US) and photobiomodulation (PBM) are promising treatment modalities for restoring articular cartilage. Owing to their different mechanisms of action, individual or combined stimulation may elicit different bioeffects on chondrocytes. This study aimed to evaluate the potential of US and PBM, applied alone or combined, in augmenting chondrocytes' responses toward cartilage matrix synthesis and reverting their catabolic activities, with or without interleukin-1β (IL-1β) incubation. Human chondrocytes were cultured under basal or proinflammatory conditions (1 ng/ml IL-1β) and stimulated daily for 6 days with US, PBM, US followed by PBM, and PBM followed by US. Chondrocyte activity, along with protein and mRNA expression of cartilage synthesis- and degradation-related markers, was analyzed. IL-1β incubation did not significantly affect chondrocytes' metabolic activity or sulfated glycosaminoglycans (GAGs) production. Both US and PBM, alone or combined, increased the protein and mRNA of collagen type II (COL II) and aggrecan (ACAN) under basal and proinflammatory conditions. PBM had a stimulatory effect on GAG synthesis. While PBM did not influence the expression of cartilage destruction markers, US potentiated the chondrocytes' response to inflammation by increasing metalloproteinases and IL-1β mRNA levels. The sequential combination of US and PBM induced distinct bioeffects depending on the application order, but these were not superior to the effects of individual treatments. As this study used chondrocytes from a single donor, generalizability may be limited. While both US and PBM stimulated matrix synthesis, PBM showed a comparatively greater ability to mitigate chondrocyte degradation and may be of interest for cartilage repair strategies.
Bone defect repair remains a significant clinical challenge, necessitating scaffold materials that combine excellent mechanical properties, bioactivity, and anti-infective capabilities, which are central to bone tissue engineering. Triply periodic minimal surface (TPMS) structures have garnered considerable attention due to their superior mechanical and biological characteristics, demonstrating great potential in the design of bone repair scaffolds. This review summarizes the latest advances in three-dimensional printed anti-infective tissue engineering scaffolds based on TPMS structures within the field of bone regeneration. It highlights the design advantages of TPMS architectures, the performance of composite materials such as polylactic acid/magnesium titanate, and the antimicrobial mechanisms of these scaffolds. Furthermore, the synergistic effects of promoting osteogenesis and combating infection are analyzed. By systematically collating current research findings, this article aims to provide a theoretical foundation and guidance for the development of next-generation multifunctional bone repair materials.
Platelet membranes (PMs) are increasingly explored as bioinspired coatings for nanoparticles (NPs), providing improved immune evasion, prolonged circulation, and disease-homing properties that enhance targeted drug delivery. Unlike conventional NPs that rely mainly on passive targeting, PM-coated systems expose platelet surface markers such as CD47, GPIb, and P-selectin, enabling vascular adhesion and selective localization to tumors or thrombi. PM–NPs are thus increasingly regarded as promising carriers for oncology, cardiovascular, and infectious disease therapies. This review introduces the various bioengineering principles underlying PM–NP fabrication, including points to consider for platelet sourcing, membrane isolation, and coating strategies. Achieving reliable quality control (QC) and reproducibility depends on rigorous assessment of critical formulation variables, including nanoparticle size, surface charge, and the preservation of functional membrane proteins. The implementation of scientific approaches and regulatory standardization frameworks, such as the Minimal Information for Studies of Extracellular Vesicles guidelines, and Food and Drug Administration/European Medicines Agency (FDA/EMA) regulatory expectations, is critical to establish reproducibility and facilitate regulatory acceptance of PM–NP technologies, guiding their advancement toward clinical-grade production. Furthermore, we highlight translational opportunities and the complementary potential of platelet-derived extracellular vesicles, which share similar surface markers, yet offer intrinsic nanoscale size, endogenous bioactivity, and improved stability. By integrating robust engineering design with standardized QC practices, PM–NPs can progress from laboratory research to clinically viable therapeutics, establishing a relevant benchmark for future cell membrane-based nanomedicines.
Chirality is an intrinsic characteristic of living systems, manifesting as a pervasive asymmetry from the molecular to the cellular level. This asymmetry regulates normal life activities through precise stereospecific recognition between molecules and between molecules and cells. Under physiological conditions, L-amino acids constitute proteins that support metabolic functions, right-handed helical deoxyribonucleic acid (DNA) stores genetic information, and right-handed sugars provide energy. At the cellular level, the non-centrosymmetric arrangement of the cytoskeleton guides the left-right axial positioning during embryonic development and organ formation. A certain degree of chiral inversion occurs under normal physiological conditions—for instance, trace amounts of D-amino acids modulate neurotransmitter release, and low level of left-handed DNA promotes double-strand unwinding, facilitating transcription. However, excessive accumulation of D-amino acids is closely associated with Alzheimer's disease, chronic kidney di'ease, diabetes, and aging. Similarly, the presence of substantial left-handed DNA fragments can lead to genomic instability, “increasin” sus'eptibility to tumorigenesis. Moreover, abnormalities in cellular chirality may contribute to vascular endothelial barrier disruption and improper left–right organ positioning. Therefore, monitoring aberrant chiral molecules and cells that deviate from the normal range holds promise for the early diagnosis of diseases such as nephropathy, Alzheimer's disease, diabetes, and cancer. This article primarily reviews the dynamic chiral balance under physiological and pathological conditions, providing a reference for the application of chirally inverted molecules and cells Is potential novel biomarkers for the early diagnosis of diseases.
Force-induced protein conformational changes govern many essential biological processes, yet their molecular mechanisms remain difficult to resolve. Von Willebrand factor (VWF), a central regulator of hemostasis, is activated by hydrodynamic forces in blood flow, but how mechanical signals propagate across its multidomain architecture is poorly understood. Here, we use flow molecular dynamics (FMD), a simulation framework that applies fluid forces via controlled solvent flow to interrogate mechanosensitive proteins. Using VWF as a model system, we reconstructed the complete mechanomodule (D′D3–A1–A2–A3; 1110 residues) with native glycosylation by integrating crystallographic data and ColabFold predictions. FMD simulations capture a force-driven transition from a compact, autoinhibited “bird's nest” ensemble to an extended, activated state, revealing asymmetric autoinhibitory strengths within the N′AIM and C′AIM modules of the A1 domain. By directly linking static structures to dynamic, force-regulated behavior, this work establishes a generalizable platform for dissecting protein mechanosensitivity and enabling the rational design of force-responsive therapeutics.
We present a wireless and handheld optical elastography probe aimed toward improving intraoperative discrimination between malignant and benign tissue in breast-conserving surgery. If successful, this probe can contribute to reducing close or positive margins and, therefore, subsequent re-excisions. The probe visualizes mechanical contrast between tumor and surrounding benign tissue in excised human breast specimens using stereoscopic optical palpation, in which the deformation of a compliant silicone layer is measured by two parallel cameras to infer surface stress, where variations in stress correspond to differences in the mechanical properties of the underlying tissue. Wireless operation is achieved using a Wi-Fi transceiver to transmit images at 15 fps to a laptop for processing. To enhance image quality, we incorporate computational optical palpation, which utilizes finite element analysis to provide a more accurate mechanical model of the deformation of the compliant layer. This approach yields a twofold improvement in spatial resolution, from 1034 to 512 μm, and a 55% increase in stress contrast in a structured silicone phantom. In a preliminary study on four excised human breast tissue samples, we demonstrate that the probe can identify tumor and distinguish between benign tissue types, including adipose tissue, stroma, and potentially ducts.
This paper presents a wireless mobile microrobot gripper for the pick-and-place bioassembly of cell spheroids, which are crucial for tissue engineering. To address the risk of cellular damage during handling, this technology integrates real-time force sensing, enabling controlled manipulation of delicate biological materials. The microscale, untethered design allows for high maneuverability during the construction of complex, multi-spheroid constructs. Experimental results demonstrate the system's effectiveness in creating precise, heterogeneous patterns while maintaining high cell viability. This force-aware microrobotic platform overcomes a barrier in biofabrication, paving the way for the gentle and precise construction of complex tissue models for biomedical engineering.
Morphological changes in spheroids and organoids are widely used as in vitro indicators of healthy and diseased tissue function, but selecting appropriate methods to quantify these changes remains challenging. Shape factors (or shape descriptors) are dimensionless metrics often computed using ImageJ/FIJI; however, their ability to classify specific morphological features can vary. To address this challenge, we developed a clinically inspired, custom MATLAB algorithm to quantify the variance in radial lengths of invasive protrusions in spheroids and organoids. We then compared the advantages and limitations of this approach with conventional ImageJ/FIJI shape descriptors to guide users in selecting the most appropriate method for classifying spheroid and organoid morphology in their specific settings. To this end, we first analyzed digital phantoms and then performed the same comparisons using images from experimental spheroid and organoid datasets. By enabling numerical morphological readouts, shape factor analysis can enhance phenotypic profiling of spheroids and organoids and provide valuable metrics for in vitro studies, including high-throughput and drug screening workflows.
As a primary method for tissue repair and functional reconstruction, flap transplantation has achieved a clinical success rate of over 90%. However, the postoperative incidence of vascular crisis remains as high as 10%–30%, making it a leading cause of reoperation and disability. Flap temperature is a key indicator closely correlated with microcirculatory status, making its monitoring essential for the early detection of complications. This paper provides a systematic review of the physiological mechanisms underlying postoperative flap temperature, the characteristic temperature changes associated with venous and arterial crises, and the latest advancements in monitoring technologies. It comprehensively analyzes the principles, advantages, and limitations of various methods, including manual palpation, contact thermometry, infrared thermography, fiber optic sensing, and microwave thermometry. Furthermore, the review explores the application of intelligent technologies such as wearable sensors, artificial intelligence-driven predictive systems, implantable flexible devices, and multimodal fusion monitoring. Current challenges, including poor real-time performance, low precision, and a lack of standardization, are highlighted. Future development is directed toward precision, intelligence, and integration, with an emphasis on multidisciplinary collaboration to create more accurate, convenient, and intelligent monitoring systems. These advancements aim to achieve precise early warning and timely intervention, ultimately improving flap survival rates and patient outcomes.
Resident cardiac macrophages, derived from primitive yolk sac precursors during embryogenesis, have increasingly been recognized for their distinct phenotype and functions in regulating homeostasis of the human heart. However, the profile of their extracellular vesicles (EVs) in cardiac signaling and regulation remains uncharted. Here, we employ differentiation of human pluripotent stem cell-derived primitive macrophages (Mac), harvesting their secreted EVs and performing in-depth characterization of associated microRNAs (miRNAs). Primitive macrophages secreted nanoscale EVs that expressed canonical EV markers, and miRNA sequencing highlighted a diverse and unique profile of miRNAs when compared to EVs sourced from other principal cardiac cell lineages and published data from monocyte-derived cells. In particular, we noted the abundance and enrichment of vascular-modulatory let-7 miRNAs and miR-126-3p. Functional screening of Mac-EVs in a 3D model of in vitro cardiac vasculogenesis confirmed enhanced early endothelial cell organization and branching. Establishing a reference for the human Mac-EV miRNome enables further hypothesis-driven mechanistic tests of Mac-EV miRNAs in mediating cardiac physiology and disease, opening the door to identification of therapeutic targets and modalities for cardiac repair.
Myocardial infarction (MI) poses a severe threat to human life and health. During acute MI, persistent myocardial ischemia and hypoxia induce pathological alterations in the microenvironment. Traditional therapeutic approaches exhibit limited capacity for targeted modulation of this infarcted microenvironment. Consequently, developing therapeutic strategies capable of precisely responding to the pathological microenvironment holds significant importance. Hydrogels, as a class of polymeric biomaterials with excellent biocompatibility, can be engineered into intelligent responsive hydrogels by incorporating environmentally responsive functional groups or constructing intelligent network architectures. These hydrogels are designed to sense and respond to key features of the MI pathological microenvironment, such as temperature, pH, reactive oxygen species, and enzyme concentrations. This review systematically summarizes the design strategies and research advances in intelligent responsive hydrogels for MI therapy over recent years, focusing on their distinct functional capabilities: alleviating oxidative damage, suppressing excessive inflammatory responses, enabling precise drug delivery, and modulating immune activity. Although current research predominantly remains at the preclinical stage and faces numerous challenges, the convergence of materials science and biomedical engineering positions smart responsive hydrogels as promising candidates to deliver innovative solutions for the precise treatment of MI.
Mechanical cues control key aspects of cardiac structure formation and function from heart development through adult life. Because the heart is a pump, forces from muscle contraction and blood flow generate normal and shear stresses that, together with matrix stiffness, regulate cell fate, growth, and homeostasis through mechanotransduction. This review describes how mechanosensors in cardiomyocytes, endothelial cells, and fibroblasts, including integrins and stretch-activated ion channels, couple mechanical stimuli to their cellular responses. We outline pathways that translate force into key phenotypes relevant to morphogenesis, homeostasis, and disease progression, with emphasis on RhoA/ROCK, calcium, and Yes-associated protein (YAP) signaling. We also explain how elevated mechanical load driven by hypertension activates hypertrophic and fibrotic remodeling of cardiac chambers, particularly through transforming growth factor-β, integrins, YAP, and calcineurin signaling. Finally, we highlight emerging roles for mechanosensitive microRNAs in coordinating proliferation, metabolism, electrophysiology, and extracellular matrix dynamics in the heart. Since most, if not all, of these pathways are interconnected, a comprehensive understanding will require high-resolution maps of cardiac mechanical environments and clear links between defined stimuli and cell-type-specific responses. These insights will advance fundamental understanding and guide the development of more effective therapeutic strategies.
Rapid and quantitatively accurate detection of HIV (human immunodeficiency virus) viral load using a simple workflow, automated instrumentation, and real-time data processing with easily interpretable output is required for an approach to become practical for point-of-care environments. We recently demonstrated a form of interferometric scattering microscopy called Photonic Resonator Interferometric Scattering Microscopy (PRISM) that amplifies the contrast of surface-attached nano-objects via a photonic crystal (PC) surface. Recently, our team also developed net-shaped DNA nanostructures called “Designer DNA Nets” (DDN) that organize multivalent aptamer arrays to precisely match the pattern of proteins on the outer surface of intact virions to provide high-affinity and selective binding. In this work, we demonstrate the combination of DDNs and PRISM for detection of HIV by digital counting of captured viruses. We compare multivalent DDN-based viral capture to monomeric aptamer and nanobody capture, in which the captured virions are tethered to the PC surface by a DNA linker. We observe that tethered virions are not fully stationary and that their localized dynamic movement provides a route for label-free digital-resolution detection with a signal-to-noise ratio of 50, while disregarding the presence of image features not related to specific virus capture. We obtain a detection limit of 104 virions/ml with a single-step, room temperature 30-min assay and excellent selectivity for non-detection of a nonspecific virus and the presence of a high concentration of extracellular vesicles. This study highlights PRISM's utility as a means for versatile detection of immobilized particles as part of an assay for affinity molecule evaluation.
