Search Results (434)

Iron-based nanoparticles, particularly iron oxide nanostructures (IONPs), have emerged as versatile and clinically relevant platforms for drug delivery and theranostic applications. Among these, superparamagnetic iron oxide nanoparticles (SPIONs), including magnetite (Fe₃O₄) and maghemite (γ-Fe₂O₃), are the most extensively investigated due to their biocompatibility, magnetic responsiveness, and established safety profiles. Their unique superparamagnetic behavior enables external magnetic-field-guided targeting, magnetic resonance imaging (MRI) contrast enhancement, and magnetically triggered hyperthermia, enabling simultaneous diagnosis and therapy. Surface functionalization with polymers, silica, lipids, peptides, and biomolecules further improves colloidal stability, circulation time, targeting specificity, and controlled drug release. Core–shell architectures and multifunctional hybrid systems have expanded the therapeutic scope of iron nanoparticles, integrating chemotherapy, gene delivery, photothermal therapy, and Fenton reaction–mediated catalytic therapy. Despite promising preclinical outcomes, challenges remain regarding long-term biosafety, oxidative stress induction, biodistribution, large-scale reproducibility, and regulatory translation. This review summarizes the physicochemical properties, synthesis strategies, surface-engineering approaches, drug-loading mechanisms, and biomedical applications of iron-based nanoparticles, highlighting recent advances in multifunctional and peptide-functionalized systems. Critical considerations for clinical translation and future perspectives in precision nanomedicine are also discussed. Full article

Four-dimensional (4D) printing integrates additive manufacturing with stimuli-responsive materials to fabricate biomedical implants and functional healthcare devices that undergo programmed, time-dependent changes in shape or function. Unlike static 3D-printed constructs, 4D-printed systems can respond to clinically relevant stimuli such as temperature, hydration, pH, light (including near-infrared), magnetic fields, or electrical inputs. These triggers drive defined actuation mechanisms, most commonly thermomechanical shape-memory recovery, swelling-induced morphing, and magnetothermal activation. This review synthesizes the principal material platforms used for biomedical 4D printing, including shape-memory polymers and alloys, hydrogels, liquid-crystal elastomers, and responsive composites, and links material choice to device behavior and translational feasibility. Applications are discussed across self-expanding stents, cardiac occluders, tissue-engineered constructs, implantable drug delivery systems, and adaptive wearables. Key translational challenges include sterilization compatibility, manufacturing reproducibility and quality control, safe stimulus delivery, predictable biodegradation and long-term biocompatibility, and regulatory pathway definition. Full article

The efficacy of traditional antimicrobial treatments has been largely compromised due to the high occurrence of multidrug-resistant (MDR) pathogens, therefore underlining the limitations of existing drug delivery mechanisms. Pathogens resist pharmacological treatment via different mechanisms, including efflux pump overexpression, biofilm formation, and enzymatic destruction. The application of nanorobotics or controllable nanoscale devices has gained considerable attention for overcoming shortcomings while connecting biomedical engineering, materials science, and microbiology. Despite advancements in nanomedicine, there is still no suitable nanorobotic system applicable against MDR pathogens. Previous studies highlighted device categories and materials but did not explain the detailed nanorobotic mobility, sensing, and programmability to counteract biological resistance. This review combines cross-disciplinary discoveries to design a mechanistic and translational model for nanorobotics effective in controlling infectious diseases while focusing on the advancements in nanorobotic technologies over the past six years (2020–2025), with emphasis on translational readiness, biosafety issues, scalability, regulation, and their mechanistic ability to overwhelm MDR complications. Databases from different publishers, including PubMed, Scopus, and Web of Science, were used to select studies focusing on the potential of emerging nanorobotic therapeutic technologies, such as magnetic microrobots, catalytic nanoswimmers, and DNA origami nanodevices, and their application to bacterial biofilms and antibiotic drug delivery. Evidence from the literature shows that magnetically driven microrobots, catalytic nanoswimmers, and DNA origami structures can actively destroy biofilms, enhance antibiotic penetration, and perform site-specific antimicrobial administration. Nevertheless, most of these innovations remain in the preclinical or prototype stage, hindered by biosafety issues, immunological reactivity, poor routing precision, energy source optimization, and a lack of regulatory and ethical frameworks, which are major challenges for clinical translation. Full article

Droplet manipulation constitutes a fundamental operation in numerous bio-microfluidic applications, including but not limited to medical diagnostics and targeted drug delivery. Among the various technologies developed for this purpose, magnetic digital microfluidics (MDMF) has emerged as a compelling approach due to its inherent advantages of contamination-free actuation, low cost, and configurational flexibility. Nevertheless, conventional MDMF remains constrained by its reliance on bulky instrumentation and substantial power consumption for generating controllable magnetic fields, which limit its in-field applications. To address these limitations, this work presents a programmable and portable electromagnetic microfluidic droplet manipulation platform that synergistically integrates static and dynamic magnetic fields to enable non-contact, high-precision droplet control under ultra-low power conditions. The proposed system comprises an electromagnetic actuation module, a permanent magnet, and a glass substrate coated with Teflon film. The entire system is secured by a PMMA support structure, within which a glass substrate is mounted and spatially separated from the permanent magnet. The PMMA support is fabricated using a milling process, offering a simple manufacturing procedure and high structural reusability and reproducibility. The control logic is implemented on a field-programmable gate array (FPGA) development board, facilitating fully autonomous operation powered by a standard battery. The platform operates at a low voltage of 3.5 V and a driving current of 180 mA, corresponding to a total power consumption of merely 0.63 W, while achieving robust manipulation of droplets in the volume range of 0.5 to 5 μL. A maximum average droplet velocity of up to 0.6 cm/s was attained under optimal conditions. The proposed platform offers a scalable and energy-efficient solution for portable droplet-based assays and holds significant promise for integration into point-of-care diagnostic tools and field-ready biochemical analysis systems. The platform demonstrates excellent operational stability and reproducibility, as validated by repeated actuation experiments with a positioning deviation of approximately 0.1 mm under optimized conditions. The fabrication process also exhibits high reliability with consistent performance across multiple experimental runs. Full article

Objective: Inadequate radiation delivery to recurrent pelvic and abdominal tumors is frequently attributable to the dose limitations of surrounding normal structures, particularly the intestines. Radiotherapy guided by magnetic resonance imaging (MRI) significantly enhances the accuracy of soft-tissue delineation. The purposes of this study were to demonstrate the feasibility and effectiveness of MR-Linac Adaptive stereotactic body radiotherapy in patients with pelvic–abdominal recurrent or metastatic gynecological malignancies with or without systemic therapies. Methods: Patients with pelvic–abdominal recurrent or metastatic gynecological malignancies are eligible for MR-Linac Adaptive stereotactic body radiotherapy. Systemic therapies, including chemotherapy, immunotherapy, and targeted therapy, are considered acceptable treatment options. The safety, tolerability, and efficacy of MR-Linac Adaptive stereotactic body radiotherapy were assessed. Results: Between October 2019 and May 2025, 15 patients were subjected to MR-Linac Adaptive stereotactic body radiotherapy. With a median follow-up period of 4.67 months (range, 0.73–20.10 months), the 6-month overall survival (OS), progression-free survival (PFS), and local control (LC) rates were 93.3%, 66.0%, and 92.3%, respectively. The 12-month OS, PFS, and LC rates were 83.8%, 37.7%, and 70.5%, respectively. The best objective response rate (ORR = CR + PR) for the irradiated lesions was 73.3% (11/15 patients). MR-Linac Adaptive stereotactic body radiotherapy led to objective responses in 73.3% (11/15) of the patients. As of the data cutoff (28 May 2025), one patient experienced dose-limiting toxicity (an enteric fistula). Another patient developed grade 4 thrombocytopenia during treatment; it was considered chemotherapy-induced. Conclusions: These findings suggest that MR-Linac Adaptive stereotactic body radiotherapy is relatively effective and safe and can be an important treatment option for patients with pelvic–abdominal recurrent or metastatic gynecological malignancies. MR-Linac Adaptive stereotactic body radiotherapy exhibited acceptable tolerability, promising efficacy, and a favorable local control rate with regard to heavily pretreated advanced solid tumors. Full article

Many advances in enhanced oil recovery (EOR) take advantage of the unique properties of nanomaterials to improve characterization of formation properties, achieve conformance control during flood operations, and extend the controlled release time of polymers. Magnetite nanoparticles (nMag) have been employed in these processes due to their low cost, low toxicity, and ability to be engineered to meet desired needs, especially with the application of a magnetic field. Similarly, silica dioxide (SiO₂) and aluminum oxide (Al₂O₃) nanoparticles have been evaluated for the delivery of scale and asphaltene inhibitors. However, the injection of nanoparticles into porous media comes with the risk of formation damage due to particle deposition, which can lead to increased injection pressures and reductions in permeability. The goal of this study was to develop a method to evaluate and assess nanoparticle formulations for their potential to cause formation damage. A screening apparatus was constructed to hold small sandstone discs (~2 mm) or cores (~2.5 cm) for rapid testing with minimal material use and the capability to be used with either aqueous brine solutions or non-polar solvents as the mobile phase. Image analysis of the disc and pressure measurements demonstrated increasing deposition of nMag and face-caking when the salinity was increased from 500 mg/L NaCl (8.56 mM) to API brine (2.0 M). Similarly, when the injected concentration of silica nanoparticles in 500 mg/L NaCl was increased from 1 to 10 wt%, the back pressure increased by 55 psi, and face-caking was observed. The screening test results were consistent with traditional core-flood tests and was able to be modified to accommodate organic liquid mobile phases. The screening test results closely matched nanoparticle transport and retention measured in sandstone cores, confirming the ability of the system to rapidly screen nanoparticle formulations for potential formation damage. Full article

Magnetic nanoparticles represent the next-generation drug delivery systems, enabling drug targeting to specific organs without adverse effects on the body and with a controlled release rate. Their strengths are represented by biocompatibility, low cost, and easy drug loading; some drawbacks are aggregation and poor stability in biological media. In the present work, we synthesized magnetic core–shell structures with a magnetite core coated with layered double hydroxides (LDHs) based on Mg²⁺ or Zn²⁺ and Al³⁺ ions and loaded with meloxicam, a poorly water-soluble anti-inflammatory drug. Several syntheses have been attempted to obtain iron oxides based on the only magnetite phase. The combined use of different characterization techniques allowed us to reveal that the best product, showing the crucial room temperature superparamagnetism and a good level of compositional uniformity, was obtained from co-precipitation in nitrogen flow. The next LDH coating was successful, even if the hybrids showed the occurrence of aggregation. The drug was mainly adsorbed onto the LDH surfaces, as shown by the X-ray diffraction and Infrared Spectroscopy techniques. The loaded meloxicam amount was low, but the subsequent release into simulated body fluid could be prolonged for 4 days. Our study provides a proof of concept about the importance of a thorough characterization of the nanocomposite hybrids and their possible use for tricky drugs, such as those of class II of the Biopharmaceutical Classification System. Full article

The engineering of theranostic nanoparticles, which integrate diagnostics and therapy in a single administration, enables targeted drug delivery and disease visualization. In cancer theranostics, gadolinium-based nanoparticles are valuable tools for noninvasive magnetic resonance imaging (MRI) and provide high-resolution images of the tumor. When MRI is combined with other imaging modalities, complementary therapeutic information is obtained for more accurate identification of tumor characteristics and precise guidance of anticancer drug delivery. Among the many possible modalities combined with MRI, photoacoustic imaging (PAI) is a candidate that enables sensitive in vivo detection of tumors. We have already succeeded in synthesizing biocompatible gelatin-coated gadolinium oxide nanoparticles with a controlled size by adjusting the timing of gelatin addition, which were a highly efficient contrast agent for MR and PA dual imaging. Herein, we conjugated a clinically used anticancer drug (doxorubicin, DOX) to size-defined and biocompatible gadolinium oxide nanoparticles which are novel theranostic probes. Succinylated gelatin enabled the electrostatic conjugation of DOX with gadolinium oxide nanoparticles, and the release of DOX was controlled through the enzymatic degradation of gelatin by matrix metalloproteinases-2 and -9 (MMP-2 and MMP-9), which are highly expressed in cancer cells. The released DOX efficiently inhibited the growth of HeLa cells in vitro and the growth of the inoculated tumor tissues in vivo. The dual-modality MRI and PAI capabilities provide anatomical information that assists in the localization and targeting of theranostic probes. Full article

Ensuring efficient nutrient delivery and waste removal within the interior of three-dimensional (3D) cultures remains a major challenge in tissue engineering. Here, we demonstrate a proof-of-concept methodology that creates internally distributed driving sources to enhance diffusion and perfusion within 3D constructs. Iron microparticles or iron-containing microtubes were incorporated into collagen gels used for the 3D culture of dermal or cardiac fibroblasts, and cyclic dynamic magnetic fields were applied to the constructs. Oscillatory motion of the iron particles enhanced diffusion within the gels, as evidenced by increases in the fast diffusion coefficient of more than threefold and the slow diffusion coefficient of more than tenfold under conditions suitable for cell culture. In cardiac fibroblast cultures, this enhancement significantly increased proliferation by approximately twofold and reduced cytotoxicity by half compared with controls. In contrast, no significant effects were observed in dermal fibroblast cultures. Cyclic compression of microtubes within the collagen gels induced by dynamic magnetic fields primarily resulted in cellular morphological changes, including a reduction in cell area to approximately 0.8-fold of the control values, increased cell polarization with the cellular aspect ratio rising from 1.4 to 1.9, and preferred cell orientations either parallel or perpendicular to the microtube axis. Together, these results suggest that this methodology has the potential to be developed as an effective strategy for improving diffusivity in 3D metabolic environments and for promoting angiogenesis in hydrogel-based cultures. Full article

Magnetic nanoparticles, with their excellent biocompatibility and biodegradability, serve as ideal materials for constructing targeted drug delivery systems. Iron oxide (Fe₃O₄) nanoparticles, controllably prepared via methods such as solvothermal synthesis, can be combined with mesoporous silica to construct magnetically steerable nanorobots. Such robots enable efficient drug loading and precise delivery. To address challenges in the treatment of Inflammatory Bowel Disease (IBD), including the significant side effects of systemic drugs and the low oral bioavailability and poor colonic targeting of novel food-derived drugs (e.g., capsaicin with anti-inflammatory activity), this study designed capsaicin-loaded iron oxide-mesoporous silica composite nanorobots (Cap-M@mSbots). Driven by a rotating gradient magnetic field of up to 80 mT, Cap-M@mSbots achieve large-scale emergent collective locomotion, with a maximum collective locomotion velocity reaching 180.7 μm/s, and are capable of long-distance movement overcoming millimeter-scale obstacles. This system can be actively propelled to colonic lesion sites under magnetic guidance, achieving targeted drug enrichment and sustained release, thereby offering a novel strategy for the targeted therapy of IBD. Full article

Polysaccharide–protein composite hydrogels have demonstrated remarkable potential in targeted gastrointestinal delivery owing to their excellent biocompatibility, adjustable physicochemical characteristics, and intelligent responsiveness. This review provides a comprehensive overview of the underlying mechanisms and diverse applications of these composite hydrogels in gastrointestinal targeted delivery, with a particular emphasis on their stimuli-responsive release behaviors triggered by internal and external factors such as pH, enzymes, magnetic fields. Special attention is also given to their advantages in protecting sensitive bioactive ingredients, including curcumin, EGCG, probiotics. Furthermore, this review highlights their capabilities in achieving high encapsulation efficiency, smart controlled release and targeted delivery, while also presenting current challenges associated with material stability, targeting precision, large-scale production, and clinical translation. Finally, future perspectives are discussed, focusing on the development of multi-response system design, innovative biomaterials, advanced manufacturing technology applications, and AI-assisted optimization. These directions aim to provide theoretical foundations and technical strategies for advanced research and practical applications of polysaccharide–protein composite hydrogels in a targeted gastrointestinal delivery system. Overall, this review underscores the significant promise of polysaccharide–protein composite hydrogels as intelligent gastrointestinal delivery platforms and provides a systematic reference for their rational design and future translational development. Full article

RNA-based interventions are particularly promising for next-generation therapeutic strategies and hold significant potential when integrated with diagnostic modalities. Among noncoding RNAs, microRNAs (miRNAs) regulate gene expression post-transcriptionally and represent compelling targets for cancer therapy. However, their clinical translation remains hindered by instability, off-target effects, and limited delivery efficiency. Here, we report the microfluidic synthesis of hybrid lipid–polymer nanoparticles (LiPoNs) that co-deliver an AntimiR-21 and the magnetic resonance imaging contrast agent gadolinium diethylenetriamine penta-acetic acid (Gd-DTPA). The LiPoNs were obtained using coupled Hydrodynamic Flow Focusing (cHFF), enabling precise control over lipid–polymer self-assembly and surpassing the compositional limitations reported with conventional micromixers. The resulting AntimiR-21–Gd-DTPA–LiPoNs exhibited an average hydrodynamic diameter of 124 nm, narrow polydispersity (PDI < 0.2), and encapsulation efficiency up to 60%. In MDA-MB-231 breast cancer cells, treatment with AntimiR-21–LiPoNs induced suppression of miR-21 and a corresponding decrease in migratory capacity, demonstrating effective functional delivery and gene expression modulation. These findings establish a versatile microfluidic platform for engineering multifunctional lipid–polymer nanostructures whose hybrid architecture combines the biocompatibility and membrane fusion capability of lipids with the structural robustness and controlled release properties of polymers, thereby advancing RNA-based theranostic design for precision oncology and related applications. Full article

Ischemic stroke triggers hypoxia, inflammation, and oxidative stress. Local oxygen delivery may prevent secondary injuries. Herein, we implanted a catalase-incorporated thiolated gelatin-based oxygen-releasing hydrogel sheet in a rat model of photothrombosis to evaluate early infarct attenuation and feasibility. Male Sprague–Dawley rats were allocated to four groups (n = 6/group): control at 24 h (G1), with hydrogel sheet at 24 h (G2), control at 72 h (G3), and with hydrogel sheet at 72 h (G4). Focal ischemia was induced with Rose Bengal and targeted illumination through a 6.0-mm cranial defect. A hydrogel sheet was applied to the cortex after surgery. The infarct burden was assessed by 2,3,5-triphenyltetrazolium chloride (TTC) staining and magnetic resonance imaging (MRI), while mRNA expression levels of tumor necrosis factor-α (TNF-α), brain-derived neurotrophic factor (BDNF), and superoxide dismutase (SOD) were measured by quantitative reverse transcription PCR. Body weight was monitored as a safety measure. At 24 h, TTC showed a significant infarct reduction in G2 compared with G1. At 72 h, infarct measures did not differ significantly between G4 and G3. MRI and gene expression analyses did not show statistically significant between-group differences and are presented as exploratory outcomes. Weight and perioperative status were similar across groups, indicating short-term tolerability. The hydrogel sheet was associated with reduced TTC-defined infarct burden at 24 h in this model; confirmatory studies will require larger, powered cohorts, longer follow-up with functional testing, and in vivo oxygen release profiling to optimize dose, placement, and exposure time. Full article

Oxaliplatin (OXA) is a chemotherapeutic agent that suffers from poor pharmacokinetics and off-target toxicity. To enable controlled OXA release, we engineered a multi-functional iron oxide nanoparticle (IONPs) drug delivery system, based on pH-responsive mesoporous Fe₃O₄ (Fe₃O₄@MSN-NH₂) nanoparticles (NPs), conjugated with folic acid (FA) for receptor-mediated targeting and guided by a magnetic robot platform (MRP) under simulated physiologically relevant dynamic circulation/flow system. For FA-conjugated NPs (Fe₃O₄@MSN-NH₂/FA), ~29.73% OXA loading was achieved compared to ~10.3% in controls (Fe₃O₄@MSN-NH₂/OXA), quantified by ICP-OES. Under dynamic circulation flow over 48 h, MRP enhanced pH-responsive OXA release (quantified by HPLC-UV), reaching ~92% and 88% (Fe₃O₄@MSN-NH₂/OXA and Fe₃O₄@MSN-NH₂/FA, respectively) at pH 5, versus 47% and 40% (Fe₃O₄@MSN-NH₂/OXA and Fe₃O₄@MSN-NH₂/FA, respectively) without MRP, demonstrating precise control in acidic tumor-mimicking conditions. MRI relaxometry exhibited strong T2-weighted contrast (T2 = 0.015 s at 50 μg/mL for Fe₃O₄@MSN-NH₂/FA/OXA), confirming theranostic potential. Reverse transcription quantitative polymerase chain reaction (RT-qPCR) studies revealed variable Folate receptor alpha (FOLR1) expression among colorectal cancer cell lines (Caco2, SW620, SW48, and T84), with Caco2 demonstrating high levels. MTT assays indicated selective targeting of FOLR1-positive cells by FA-functionalized NPs (Fe₃O₄@MSN-NH₂/FA). This multi-functional drug delivery system integrates targeted delivery, MRP release, and real-time imaging, offering a promising technique for precision oncology. Full article

The aim of this study was to synthesize alginate hydrogel beads using ionotropic gelation containing pH-sensitive magnetic reduced graphene oxide (MGO). MGO was prepared using a hydrothermal method and surrounded by alginate beads. FTIR, XRD, FESEM, TEM, VSM and TGA showed that the synthesized beads have a quasi-spherical structure, exhibit superparamagnetic behavior, and are thermally stable up to 350 °C. The model drug, quercetin, was loaded into these particles with an efficiency of 25.8%. These particles showed a pH-dependent release. HFF-2 and Caco-2 cells were used to investigate cytotoxicity. At a concentration of 140 μg/mL, more than 80% viability was observed in HFF-2 cells and anticancer effects were observed on Caco-2 cells with a decrease in viability of less than 50% at a concentration of 200 μg/mL. The obtained cell culture results indicate that the hydrogel beads are biocompatible and act as a drug delivery system. Full article