Search Results (9,901)

Phenol red is a widely used, low-cost, label-free colorimetric pH indicator that bridges traditional colorimetric assays with modern quantitative imaging and cell-based screening platforms. Its protonation-dependent absorbance shift (430–560 nm) allows for the real-time monitoring of extracellular acidification, which indirectly reflects cellular metabolism, growth, and respiration. Although phenol red lacks the molecular specificity of genetically encoded or fluorogenic biosensors, it remains useful in systems where pH changes are effective proxies for physiological processes. Existing tissue digestion protocols often overlook key parameters, especially pH control and enzyme cofactor use. This study presents a straightforward, spectrophotometric method to monitor and adjust the pH of low-volume (1 mL) buffered enzymatic dissociation media using phenol red and a plate reader. We titrated dissociation solutions to physiological pH (~7.4) using spectrophotometric pH measurements validated against conventional glass pH probe readings, confirming method reliability. Accurate pH assessment is critical for isolating viable primary cells for downstream applications such as tissue engineering, single-cell omics, and neurophysiological assays. We highlight that papain-based dissociation media supplemented with L-cysteine can be acidic (pH 6.6) if unadjusted, compromising cell viability. This accessible approach enhances reproducibility by promoting pH documentation concerning dissociation conditions that contribute to advancing consistency in biomedical, cellular, neuronal, and tissue engineering research. Full article

Collagen is well-known as an essential and structural protein in the body and is classified into many types, with different roles. Type I collagen is the most abundant, offering firmness, elasticity, and resistance to the skin. Starting from natural resources such as calf, American buffalo hide, turkey, and perch skin, this research aims to develop a comparative study between the porous matrices obtained from collagen, extracted in the form of gel, with potential medical use. The extracted collagen gels were analyzed for their proximate analysis. The structural conformation of the gels was confirmed using circular dichroism measurements. The extracted collagen gels were dried using a freeze dryer in the form of porous matrices, and structural analyses were performed using FT-IR. Further, the collagen scaffolds were assessed for biocompatibility using an XTT assay. The water swelling behavior, the morphology, and the thermal stability of the collagen matrices were determined. The collagen porous matrices presented good antimicrobial activity, especially COLL_P, which presented the highest inhibition zone, making them suitable for biomedical uses. Overall, this study provides a method for producing collagen matrices from various sources for biomedical applications. Full article

The detection and monitoring of ions are essential for a broad range of applications, including industrial process control and biomedical diagnostics. Traditional ion-sensitive field-effect transistors require bulky and expensive reference electrodes, which face several limitations, including device miniaturization, high fabrication costs, and incompatibility with semiconductor manufacturing processes. Here, we introduce a reference-less semiconductor ion sensor (RELESIS) that utilizes anodic aluminum oxide film as both the sensitive and dielectric layer. The RELESIS is composed of a metal-oxide-semiconductor field-effect transistor and an interdigital electrode, which fundamentally eliminates the need for a reference electrode, thereby enabling device miniaturization. During fabrication, the anodic oxidation process is employed in place of the expensive atomic layer deposition method, significantly reducing manufacturing costs while maintaining high surface quality. In practical measurements, the RELESIS device demonstrated an excellent pH sensitivity of 57.8 mV/pH with a low hysteresis of 7 mV. As a proof-of-concept application, the RELESIS device was employed for real-time, non-destructive monitoring of milk freshness, accurately detecting pH changes from fresh to spoiled in milk samples. The combination of reference-less structure, low-cost fabrication, and superior sensing performance positions this technology as a promising platform for next-generation portable ion sensing systems in food safety, environmental monitoring, and point-of-care diagnostics. Full article

This review focuses on hydrogel-based systems specifically designed for non-opioid analgesics, aiming to improve efficacy, safety, and translational applicability. The opioid crisis has intensified the need for safer and more effective alternatives in pain management. Non-opioid analgesics including NSAIDs, acetaminophen, gabapentinoids, antidepressants, anticonvulsants, NMDA receptor antagonists, topical agents, and cannabinoids offer promising options but are limited by rapid clearance, short half-lives, and off-target effects. Hydrogel-based drug delivery systems present a novel solution by enabling controlled, localized, and sustained release of analgesics, thus improving therapeutic efficacy and minimizing systemic toxicity. Advances in stimulus-responsive, self-healing, mechanically robust, and hybrid or nanocomposite hydrogels have broadened their biomedical applications and clinical relevance. This narrative review summarizes key hydrogel technologies and their integration with non-opioid analgesic agents. We explore encapsulation strategies, drug release mechanisms, and emerging clinical data, while also addressing critical challenges such as biocompatibility, mechanical durability, and translational scalability. Interdisciplinary collaboration between material scientists, clinicians, and regulatory experts is essential to advance hydrogel-based therapies from bench to bedside. Overall, hydrogel platforms hold transformative potential in optimizing non-opioid analgesic delivery and redefining the future of pain management. Full article

Single-molecule nanopore sensors have enabled real-time detection of enzymatic cleavage events, yet achieving sensitive and specific analysis of protease activity remains an important challenge for diagnostic applications. We engineered OmpG nanopore constructs incorporating thrombin recognition peptides into loop 6 with varied flexible and negatively charged linkers to optimize accessibility and cleavage. SDS-PAGE gel analysis showed that constructs with the recognition peptide placed after residue D225 and incorporating dual linkers achieved cleavage efficiencies up to 95%, whereas constructs without linkers showed limited cleavage. Single-channel recordings revealed that linker integration modulates pore conductance, with extended loops exhibiting intermediate open-state currents near 18 pA compared to 25 pA in wild-type OmpG. Upon thrombin addition, rapid and irreversible current drops confirmed real-time protease activity detection. These results demonstrate the critical role of linker design, particularly flexibility and charge, in optimizing nanopore protease sensors, providing a versatile platform for biomedical applications. Full article

The demand for effective antibacterial materials is growing rapidly in today’s world. Both metallic and metal oxide nanoparticles have been widely used as antibacterial agents against various bacterial species due to their unique mechanisms of destroying bacterial membrane cells. The current study explores the antibacterial activity of centrifugally spun fibers prepared from copper acetate polyvinylpyrrolidone (PVP) ethanol precursor solutions against both Gram-negative and Gram-positive bacteria. During the synthesis of the composite fibers, the physical and chemical conditions were optimized. The structure and morphology of the PVP/Cu-Ac fibers were analyzed using scanning electron microscopy (SEM), X-ray diffraction (XRD), energy-dispersive X-ray spectroscopy (EDS), and thermogravimetric analysis (TGA). The antibacterial activity of PVP/copper acetate fibers was tested against Gram-positive Staphylococcus aureus and Gram-negative Escherichia coli. The PVP/Copper acetate fibers demonstrated bactericidal activity against both bacterial strains, making the PVP/copper acetate composite fibers an effective material for biomedical applications. Full article

Despite the widespread use of photopolymerizable methacrylate resins in additive manufacturing, their potential for creating functional biomedical materials remains untapped. Standard resins, while possessing good technological properties, are typically biologically inert and unable to combat such a critical problem as bacterial colonization. In this work, we propose incorporating selenium nanoparticles (Se NPs) into a photopolymerizable resin based on methacrylate monomers to obtain functional composite materials in the MSLA printing process. Composite material samples made from modified resins showed no structural surface defects and were characterized by a non-uniform distribution of NPs in volume and demonstrated a higher degree of monomer conversion. The materials demonstrated significant antioxidant activity, removing OH-radicals and H₂O₂ and reducing the level of biomarkers of oxidative damage (8-oxoguanine in DNA and long-lived reactive protein species). A dose-dependent bacteriostatic effect was observed in E. coli cell cultures against a background of high cytocompatibility with human cell cultures. The developed photopolymerizable resins modified with Se NPs allow obtaining products that combine the properties of a bacteriostatic agent with antioxidant properties and high biocompatibility, which is of considerable interest in terms of materials for biomedical applications. Full article

Hydrogel microneedles (HMNs) act as non-invasive devices that can effortlessly merge with the human body for drug delivery and diagnostic purposes. Nonetheless, their improvement is limited by intricate and repetitive issues related to material composition, structural geometry, manufacturing accuracy, and performance enhancement. At present, there are only a limited number of studies accessible since artificial intelligence and machine learning (AI/ML) for HMN are just starting to emerge and are in the initial phase. Data is distributed across separate research efforts, spanning different fields. This review aims to tackle the disjointed and narrowly concentrated aspects of current research on AI/ML applications in HMN technologies by offering a cohesive, comprehensive synthesis of interdisciplinary insights, categorized into five thematic areas: (1) material and microneedle design, (2) diagnostics and therapy, (3) drug delivery, (4) drug development, and (5) health and agricultural sensing. For each domain, we detail typical AI methods, integration approaches, proven advantages, and ongoing difficulties. We suggest a systematic five-stage developmental pathway covering material discovery, structural design, manufacturing, biomedical performance, and advanced AI integration, intended to expedite the transition of HMNs from research ideas to clinically and commercially practical systems. The findings of this review indicate that AI/ML can significantly enhance HMN development by addressing design and fabrication constraints via predictive modeling, adaptive control, and process optimization. By synchronizing these abilities with clinical and commercial translation requirements, AI/ML can act as key facilitators in converting HMNs from research ideas into scalable, practical biomedical solutions. Full article

Pattern recognition and machine learning algorithms have become integral to modern drug discovery, offering powerful tools to uncover complex patterns in biomedical data. This article provides a comprehensive review of state-of-the-art pattern recognition techniques—including traditional machine learning (e.g., support vector machines), deep learning approaches, genome-wide association studies (GWAS), and biomarker discovery methods—as applied in pharmacogenomics and computational drug repurposing. We discuss how these methods facilitate the identification of genetic factors that influence drug response, as well as the in silico screening of existing drugs for new therapeutic uses. Two antiviral agents, ribavirin and lopinavir, are examined as extended case studies in the context of COVID-19, illustrating practical applications of pattern recognition algorithms in analyzing pharmacogenomic data and guiding drug repurposing efforts during a pandemic. We highlight successful approaches such as the machine learning-driven prediction of responders and the AI-assisted identification of repurposed drugs (exemplified by the case of baricitinib for COVID-19), alongside current limitations, including data scarcity, model interpretability, and translational gaps. Finally, we outline future directions for integrating multi-omics data, improving algorithmic interpretability, and enhancing the synergy between computational predictions and experimental validation. The insights presented highlight the promising role of pattern recognition algorithms in advancing precision medicine and accelerating drug discovery, while recognizing the challenges that must be addressed to fully realize their potential. Full article

Poly(L-lactide) (PLA) is a promising biopolymer for biomedical applications due to its biodegradability and biocompatibility; however, its brittleness restricts its use in fused deposition modeling (FDM). To overcome this limitation, flexible PLA monofilaments with enhanced mechanical performance and printability were developed. In this study, PLA was melt-blended with acetyl triethyl citrate (ATEC, 1.0–5.0 wt%) as a plasticizer and zinc phenyl phosphonate (TMC-200, 0.3 wt%) as a nucleating agent. It was found that the PLA with 3.0 wt% ATEC (PLA/A) exhibited the greatest flexibility, while the addition of TMC-200 further improved tensile strength and ductility. Specifically, the ternary blend of PLA/TMC-200/ATEC (PLA/T/A) exhibited a synergistic effect, achieving superior mechanical properties (tensile strength: 35.0 MPa, elongation at break: 232.0%, compared to 12.1% for pure PLA) and raising the degree of crystallinity (X_c) from 4.7% to 45.0%. Monofilaments (1.70 ± 0.05 mm) fabricated from PLA/T/A exhibited smooth surfaces, balanced mechanical performance, and excellent cytocompatibility (over 99% cell viability in L929 fibroblasts). Moreover, FDM-printed specimens retained enhanced mechanical and thermal performance, demonstrating material stability after processing. Shelf-life testing further confirmed the structural integrity of PLA/T/A monofilament after 8 weeks at 50 °C. Overall, PLA/T/A provides an effective strategy for producing high-performance, medical-grade PLA monofilaments with improved toughness, printability, and biocompatibility, enabling their application in biomedical 3D printing. Full article

Hydrogels have attracted considerable attention as biomedical materials owing to their distinctive properties; however, improvements in mechanical strength, biodegradability, and biocompatibility remain essential for advanced clinical applications. This study developed a new dual-crosslinked hydrogel based on gelatin (Gel) and dextran (Dex) via sequential aldimine condensation and photopolymerization. Natural Gel and Dex were functionalized to synthesize methacrylated Gel (GelMA) and oxidized Dex (ODex), respectively. An imine-linked network was initially formed between GelMA and ODex via aldimine condensation, followed by a second crosslinked network generated through blue-light-induced free-radical polymerization of GelMA, yielding dual-crosslinked hydrogels (GMODs). ¹H NMR and FT–IR analyses confirmed the successful functionalization and formation of dual-crosslinked structure. The dual-crosslinked network enhanced the thermal stability and water-retaining capacity of the freeze-dried hydrogels (DGMODs) while reducing the surface wettability and equilibrium swelling ratio of GMODs. The maximum compressive strength (σₘ) increased with crosslinking density; GMOD−2, with moderate crosslinking density, remained intact under 85% compressive strain and achieved σₘ of 108.0 kPa. The degradation rate of GMODs was tunable by adjusting the crosslinking density, thereby modulating their drug-release behavior. GMOD−3, possessing the highest crosslinking density, exhibited effective drug-sustained release for up to five weeks. Biological evaluations, including cytotoxicity assays, live/dead cell staining, and hemolysis tests, verified excellent cytocompatibility (cell survival rate > 92%) and minimal hemolysis ratio (<5%). Furthermore, inhibition zone tests preliminarily revealed moderate antibacterial activity for GMOD−1. The GMOD hydrogels exhibited superior compressive robustness, adjustable biodegradability, and excellent biocompatibility, holding great potential for biomedical applications such as sustained drug-delivery system. Full article

The pomegranate peel represents an important source of secondary metabolites such as hydrolysable ellagitannins, which are recognized for their antioxidant, anticancer and neuroprotective properties. In this work, the freeze-dried pomegranate peel was extracted by a combined mild maceration at room temperature and ultrasonication at 45 °C using ethanol and acetone as green solvents. The ethanol extract, with an extraction yield of 29%, and IC50 (mg/mL) 0.1067 and 0.0414 for DPPH and ABTS, respectively, was incorporated into a polymer based on dextran, using a grafting reaction, to improve its bioavailability and preserve the chemical integrity. In addition, the potential antitumor activity against breast cancer was evaluated based on the existing literature. In vitro studies have demonstrated the safety and biocompatibility of both free pomegranate peel extract (SSE2-L) and its dextran conjugate (SSPD), with no adverse effects on fibroblasts, erythrocytes, or immune cells. Both formulations inhibited the proliferation of breast cancer cell lines (MCF-7, MDA-MB-231) in a concentration- and time-dependent manner, with SSPD consistently showing superior efficacy. This enhanced activity was corroborated by reduced clonogenic growth, G1 cell-cycle arrest, and improved stability and bioactive retention conferred by polymer conjugation. Overall, these findings highlight dextran-conjugated pomegranate polyphenols as promising candidates for next-generation nutraceuticals and phytopharmaceuticals in cancer chemoprevention and adjunctive therapy, with potential applications extending to other biomedical fields and functional foods. Full article

The Ericaceae family encompasses several berries with recognized health-promoting properties; however, Macleania rupestris, a neotropical species endemic to the Andean region, remains poorly characterized. Background/Objectives: This study aimed to identify the chemical composition of M. rupestris ethanolic extracts and evaluate their biological activities, including antitumoral, hemolytic, anti-inflammatory, and leishmanicidal effects. Methods: The M. rupestris ethanolic extracts were obtained from lyophilized fruits and analyzed by HPLC-MS/MS for phytochemical profiling. Bioactivities were assessed in vitro using tumor and non-tumor cell lines (MTT assay), erythrocyte hemolysis assays, RAW 264.7 macrophage inflammation models, and Leishmania mexicana promastigotes. Results: The chemical analysis revealed anthocyanins (cyanidin-3-glucoside, malvidin-3-glucoside, petunidin-3-glucoside, delphinidin-3-arabinoside), flavonols (quercetin and myricetin derivatives), and coumaroyl iridoids. The extract showed modest antiproliferative activity (IC₅₀ 10.4–22.5 mg/mL) across tumor cell lines with low therapeutic indices, indicating limited selectivity. In contrast, hemolytic activity was negligible (<5% at all tested concentrations), suggesting high biocompatibility. Anti-inflammatory assays indicated a dose-dependent reduction in nitric oxide (NO) production, while no significant leishmanicidal activity was detected. Conclusions: This study provides the first comprehensive evaluation of the previously listed M. rupestris bioactivities. While its antitumoral effects appear limited, its strong hemocompatibility and presence of antioxidant metabolites highlight its potential for biomedical and nutraceutical applications where biocompatibility is critical. Further studies are needed to optimize bioactivity and explore potential synergistic effects. Full article

The impingement of a molten droplet on a solid surface, forming a “splat,” is a fundamental phenomenon observed across numerous industrial surface engineering techniques. For example, thermal spray deposition is widely used to create metal, ceramic, polymer, and composite coatings that are vital for aerospace, biomedical, electronics, and energy applications. Significant progress has been made in understanding droplet impact behavior, largely driven by advancements in high-resolution and high-speed imaging techniques, as well as computational resources. Although droplet impact dynamics, splat morphology, and interfacial bonding mechanisms have been extensively reviewed, a comprehensive overview of the mechanical behaviors of single splats, which are crucial for coating performance, has not been reported. This review bridges that gap by offering an in-depth analysis of bonding strength and residual stress in single splats. The various experimental techniques used to characterize these properties are thoroughly discussed, and a detailed review of the analytical models and numerical simulations developed to predict and understand residual stress evolution is provided. Notably, the complex interplay between bonding strength and residual stress is then discussed, examining how these two critical mechanical attributes are interrelated and mutually influence each other. Subsequently, effective strategies for improving interfacial bonding are explored, and key factors that influence residual stress are identified. Furthermore, the fundamental roles of splat flattening and formation dynamics in determining the final mechanical properties are critically examined, highlighting the challenges in integrating fluid dynamics with mechanical analysis. Thermal spraying serves as the primary context, but other relevant applications are briefly considered. Cold spray splats are excluded because of their distinct bonding and stress generation mechanisms. Finally, promising future research directions are outlined to advance the understanding and control of the mechanical properties in single splats, ultimately supporting the development of more robust and reliable coating technologies. Full article