Nano silica was synthesized using the Stober process with ammonia, ethanol, and tetraethyl orthosilicate (TEOS) solution. Equiatomic titanium-nickel pre-alloyed particles were reinforced with silica nanoparticles of constant volume percent with sizes varying as proceeding 50, 100, 250, and 500 nm. The weighed compositions were mixed in a planetary ball mill, followed by compaction via uniaxial compression of 50 MPa. The resultant green pellets were sintered in an argon atmosphere at 1223K for a period of 4 hrs. Following that, by using EDM, the composite pellets were sectioned, soldered, and cold-mounted. Microstructure was analyzed by optical microscopy, mechanical properties by micro-Vickers hardness testing, and electrochemical analysis by Tafel curves, whereas the effect of particle size at constant volume on the densification was determined via Archimedes' Principle. The reinforcement showed increasing hardness up to 120HV and an increase in phase distribution, in addition to the effect complemented by the transformation of silica, whereas the electrochemical evaluation was affected by both reinforcement and phase distribution. Electrochemical corrosion resistance was measured at 6.88mpy in pure TiNi and 10.93mpy in TiNi nano-silica composite.

Collagen fibers are significant constituents of connective tissues such as the skin, bone, and tendons. Their morphology and alignment are essential for understanding tissue function and pathology. Collagen fibers are conventionally observed using optical and electron microscopy, and Second-harmonic generation microscopy. This study introduces a novel microscopic imaging technique, Scattering Angle-Resolved Bioimaging (SARB), which utilizes the scattering properties of unstained specimens. The SARB is based on a conventional optical microscope with a structured illumination module that projects a checker pattern onto the sample. This allows the acquisition of images separated by the scattering angle, enabling the visualization of the scattering characteristics. We applied SARB and electron microscopy to thin, unstained formalin-fixed, paraffin-embedded (FFPE) sections of mouse skin. SARB successfully identified the location of collagen fiber bundles and revealed the scattering information within them. Importantly, these scattering patterns correlated with the orientation of the collagen fibrils, as observed in Transmission Electron Microscopy images. The use of unstained FFPE sections simplifies sample preparation, offering a practical advantage. Additionally, SARB provides access to fine structural information that is often difficult to obtain using conventional optical microscopy. These findings suggest that SARB has strong potential as a label-free, morphology-sensitive imaging method for evaluating fibrosis.

This study aimed to comparatively evaluate the manufacturing accuracy, marginal and internal fit of implant-supported permanent crowns fabricated using different brands of permanent hybrid ceramic resins via 3D printing. Additionally, these outcomes were compared with crowns produced from Vita-Enamic using the subtractive CAD/CAM technique. Six groups were formed, including five different 3D printing resins and Vita-Enamic. Crown accuracy was evaluated following ISO Standard 12836:2015. For accuracy measurements, root mean square values were calculated and recorded using Geomagic-DesignX software, based on methodologies described in the literature. Marginal and internal fit were assessed by measuring points on sectioned specimens under an optical microscope. Data were analyzed using SPSS version 22.0. The Saremco Crowntec showed (p<0,05) the highest internal and marginal fit (55,10 ± 9,433; 89,30 ± 20,966), while the Bego VarseoSmile TriniQ demonstrated the lowest marginal fit (141,70 ± 39,668) and external accuracy (92,90 ± 11,239). No significant difference was found between additive and subtractive groups in marginal fit and accuracy; the best internal fit (63,62 ± 13,352) was observed in additive groups, whereas Vita-Enamic showed (p<0,05) external accuracy (27,70 ± 6,961). Among production technologies, digital light processing exhibited (p<0,05) the lowest external accuracy (64,73 ± 25,209), with no significant difference between subtractive manufacturing and stereolithography (p>0,05). Case-specific material choice is essential. Each material has distinct advantages and limitations. Additive resins may be preferred where retention and internal fit are critical, while subtractive materials are suitable when surface accuracy is prioritized.

Lithium metal batteries offer high energy density but suffer from persistent interphase instability, where continuous corrosion, solid electrolyte interphase (SEI) growth and poor lithium deposition morphology remain key barriers to long cycle and calendar life. Here, we introduce a novel concept of dynamic monolayers on Li metal anodes, consisting of electric field-responsive molecules that assemble into packed, structured layers at the lithium interphase under an applied voltage. We employed electrochemical quartz crystal microbalance with dissipation monitoring for in situ verification of the field responsiveness and packing behavior of these molecules. Dynamic monolayers with stronger packing are found to promote more inorganic-rich SEI and chunkier lithium growth, as directly observed by cryogenic X-ray photoelectron spectroscopy and operando optical microscopy. Together, these interfacial improvements translate into enhanced Coulombic Efficiency, reduced overpotential, and improved long-term cycling stability across Li||Cu, Li||Li, ultrathin lithium (20 μm) and anode-free NMC811 configurations. Dynamic monolayers potentially provide a broadly applicable approach for tackling interfacial challenges across a range of alkali metal battery systems.

Metasurface-based optical image processing has enabled compact and low-power platforms, yet wavefront-differentiation-based metasurfaces remain fundamentally constrained by their reliance on coherent illumination and intrinsically static optical responses. Meanwhile, conventional optical microscopes rely on bulky, mechanically actuated condensers to engineer illumination numerical aperture (NA), restricting continuous tunability and preventing integration into compact or on-chip imaging systems. These limitations highlight the need for a miniaturized, electrically reconfigurable condenser capable of continuous illumination engineering under incoherent illumination within flat-optics architectures. Here, we demonstrate an electrically reconfigurable illumination-engineering (ERIE)-metalens that embeds a polyaniline (PANI) thin film within a metalens to realize a voltage-programmable condenser, enabling continuous illumination NA control and imaging-mode tuning. Leveraging the exceptional optical contrast modulation of PANI, the ERIE-metalens achieves smooth transitions between bright-field, quasi-dark-field, and dark-field imaging under incoherent light with sub-1 V operation. This continuous illumination engineering enables a quasi-dark-field regime, where transmitted and scattered light coexist in a voltage-programmable ratio, yielding hybrid contrast challenging to achieve with conventional condensers or coherent-dependent metasurfaces. Using the hybrid contrast of the quasi-dark-field, we demonstrate multimodal imaging of biological cells, simultaneously revealing overall cell morphology and fine intracellular details with a single integrated device. Our work highlights illumination engineering as an effective approach in flat optics, positioning the ERIE-metalens as an ultracompact, electrically reconfigurable, and incoherent-light-compatible platform for real-world, multifunctional optical microscopy.

This study reviews the application of wire arc additive manufacturing (WAAM) technology in maritime engineering and investigates an experimentally driven analytical approach for prediction of thermal distributions based on the Rosenthal solution. Two ER70S-6 low-carbon steel WAAM cylinders were fabricated using gas metal arc welding (GMAW) and plasma arc welding (PAW) processes, with interlayer temperatures of 453 °C and 250 °C, respectively. Accurately measuring the temperature field to tailor the microstructure has long been a challenge. The results indicated a significant deviation between the analytical predictions and the experimental data. To address this discrepancy, a hybrid approach combining analytical and experimental results was implemented. Time intervals between layers, extracted from the experimental data, were incorporated into the Rosenthal equation to improve the accuracy of temperature field predictions. The microstructure at the bottom, middle, and top regions of the WAAM components was examined using optical microscopy. Tensile testing and Vickers microhardness measurements were conducted to evaluate mechanical properties. Scanning electron microscopy (SEM) was used to analyze fracture surfaces and identify fracture modes. The results were consistent with those reported for other ER70S-6 cylindrical WAAM components. This work highlights limitations of the Rosenthal solution and emphasizes the need for thermal models in WAAM applications.

Objectives . The aim of this study is to develop and demonstrate an effective method for obtaining large-area, high-quality monolayers of molybdenum disulfide (MoS 2 ) on the surface of ferroelectric lead zirconate titanate (PZT) films which exhibit pronounced granularity and texturing. Conventional mechanical exfoliation techniques are inefficient for transferring two-dimensional materials onto nonplanar surfaces. This is due to local height variations and substrate granularity which hinder the formation of continuous monolayers and high-defect-density transferred structures. A particular challenge is the transfer onto functional substrates with surface topography characterized by heterogeneities ranging from tens of nanometers to micrometers. Methods . A gold-assisted exfoliation (GAE) method was employed, including: magnetron sputtering of a 50 nm gold film; mechanical delamination of monolayers using thermally cleavable tape; and subsequent gold etching. The characterization was performed using X-ray diffraction, optical confocal microscopy, atomic force microscopy, and second harmonic generation techniques. The efficiency of the transfer process was compared for Si/SiO 2 and PZT substrates. Results . MoS 2 crystallites with areas up to 3000 µm 2 were obtained on PZT and over 65000 µm 2 on standard Si/SiO 2 substrates, both of which exhibit minimal defect densities. Conventional mechanical exfoliation is shown to be unable to ensure transfer onto textured surfaces, whereas the GAE method preserves the monolayer character of the transferred crystallites even on nonplanar substrates. Conclusions . This work demonstrates for the first time the possibility of obtaining large-area, high-quality MoS 2 monolayers on substrates with pronounced grainy and textured structures, such as ferroelectric PZT films, using the gold-assisted exfoliation method. The work also shows that gold-assisted exfoliation is an effective technique for fabricating extended two-dimensional films with controlled morphological and structural properties, including on substrates previously considered unsuitable for such applications.

Abstract With the increasing utilisation of scrap in metallurgical processes due to recycling to reduce CO 2 footprint, the content of tramp elements in the base material is increasing. In order to quickly investigate the influence of tramp elements on the weld nugget microstructure and mechanical properties during resistance spot welding (RSW), a method has been developed to introduce tramp elements into the weld nugget. By making an indentation in one of the two sheets to be welded and inserting the desired quantity of tramp element before welding, the weld nugget can specifically be alloyed. This allows to quickly analyse the influence of individual tramp elements on the microstructure and its influence on the resulting mechanical properties. The applicability of the method was investigated using Cu as tramp element material. As part of the investigations, a targeted Cu content of 0.4 wt% was set, which was confirmed using energy-dispersive X-ray spectroscopy (EDS). The spot welds alloyed according to the method were compared with spot welds without the Cu addition and spot welds of an already Cu-alloyed material. The weld nugget microstructure of all steels analysed by light optical microscopy (LOM) and scanning electron microscopy (SEM) was martensitic with similar grain size and morphology, regardless of the Cu content. In tensile shear (TS) and cross tension (CT), testing plug failure occurred in all samples. The results from the TS tests with peak forces of 11.4–12.2 kN and absorption energies between 14.3 and 18.5 J were very close to each other. The CT results with peak forces of 6.7–8.5 kN and energies between 46 and 69 J showed a similar picture. The average weld nugget hardness of all three weld configurations was in between 383 and 398 HV1. The microstructural and mechanical results showed no significant differences. The presented method for a targeted weld nugget alloying during resistance spot welding allows a repeatable, easy and quick investigation of the influence of alloy modification by tramp elements such as Cu on the weld nugget properties and offers a practical approach to assess material changes due to an increased tramp element content.

High-radiance LED illumination systems utilizing incoherent light sources are typically limited by an inherent trade-off between achievable radiance and overall system volume. To overcome this constraint, we designed and fabricated a compact four-lens collimation system with integrated light recycling (ILRC) that combines a freeform surface lens group with a reflective ring structure to efficiently redistribute and recapture divergent light. Ray tracing analysis was performed by three discrete wavelengths (385, 430, and 475 nm) to evaluate key system parameters, including aperture, reflectivity, scattering behavior, and LED chip area. Compared to commercially available alternatives, the ILRC system achieves a reduction in total volume by nearly 50% while increasing the radiant intensity at 385 nm by approximately 65%. When implemented in optical microscopy, the system provided significantly enhanced effective radiance at the sample plane and improved image contrast, confirming its utility as a compact, energy-efficient, and high-radiance illumination solution.

Abstract The current work uses powder-mixed electrical discharge machining (PMEDM) to modify Ti–6Al–4V extra low interstitial (ELI) surface, with boric acid powder suspended in de-ionized (DI) water. The study characterizes surfaces machined by electrical discharge machining (EDM) with pure dielectric and PMEDM (15 g/L) under identical discharge conditions. Voltage–current waveforms were analyzed to evaluate spark behavior, while optical microscopy (OM), scanning electron microscopy (SEM), and transmission electron microscopy (TEM) were used for analyzing surface morphology. Cross-sectional microscopy was used to assess the thickness of the recast layer, and X-ray diffraction (XRD), energy dispersive spectroscopy (EDS), and X-ray photoelectron spectroscopy (XPS) analyses were utilized to comprehend the surface constituents. The formation of TiB and TiO2 phases was confirmed in the PMEDM sample, demonstrating chemical surface modification due to boron incorporation. TEM showed needle-shaped TiB whiskers with 0.217 nm interplanar spacing, closely matching XRD's 0.210 nm spacing. XPS validated the bonding states between Ti–B and Ti–O, supporting the formation of TiB and TiO2. Vickers microhardness (MH) testing indicated a considerable increase from 435 HV in the unmachined sample to 1125 HV in PMEDM. Dry sliding wear testing showed a significant decrease in the coefficient of friction from 0.549 to 0.292. Wettability analysis indicated a reduction in contact angle from 71.5 deg (unmachined) to 38.1 deg (PMEDM), suggesting a hydrophilic surface. TiB and TiO2 phases increase wettability, which is particularly useful in biomedical applications that need better fluid interaction. Thus, boric acid PMEDM improved Ti–6Al–4V ELI surface integrity, MH, and tribology, with DI water supporting its biomedical and eco-friendly applications.

Abstract This research investigates the behavior of polyvinyl chloride (PVC) micro composites as an electrical insulator under elevated temperature and electrical stress. Zinc Oxide (ZnO) microparticles were incorporated into the PVC matrix. ZnO fillers can improve the thermal stability, hydrophobicity, and electrical resistance of PVC insulation materials. However, it is important to understand how these composites withstand long-term deterioration in harsh environments. Various ZnO concentrations (5-30%) were used to fabricate micro composites. The samples were subjected to an accelerated aging process to simulate real-world conditions. For 200 hours, the aging process used a high voltage of 4 kV DC and a temperature of 65°C. The samples were analyzed using different analytical techniques to understand how degradation affects various material properties. Visual inspection was employed for any noticeable changes in color and texture. Optical microscopy (OM) is used to detect signs of damage or filler diffusion. Swedish Transmission Research Institute (STRI) Hydrophobicity and Contact Angle Measurements are also employed to check the water-repellency of the samples. Fourier transform infrared spectroscopy (FTIR) was employed to see functional group changes and analyze the behavior, particularly the carbonyl group (C=O) at 1719 cm -1 , which is associated with oxidation and is a significant indicator of degradation. Leakage Current Measurement techniques were also used. UV-visible spectroscopy is employed for the investigation of optical properties and possible degradation-related changes. The 15% ZnO micro composite (PZ-15) exhibited exceptional corrosion resistance. Leakage current tests show significant changes after the aging process. PZ 15 has the best hydrophobicity characteristics, the highest contact angle, and better water resistance. The degree of oxidation is determined by examining the carbonyl peak (C=O) at 1719 cm -1 . It showed a less pronounced peak than the other compounds, indicating a lower level of oxidation. These findings are consistent with previous research showing that ZnO fillers improve the resistance of PVC to different stresses, particularly at higher concentrations. The study emphasizes the importance of optimizing filler materials to improve thermal and electrical stability in their intended applications by combining data from various analytical techniques.

Abstract It is crucial to further analyze the causes of hip and knee replacement failure to better enhance the success and minimize the shortcomings of joint replacement in patient outcomes. The purpose of this study is to collect samples of failed hip and knee orthopedic implants from surgeons and analyze the features of those implants to find possible reasons for implant failure so that these causes can be successfully prevented and/or mitigated. Twelve implants were collected and cleaned according to a standard protocol. The implants were analyzed using visual observation and an optical microscope, and initial reports are presented in this study. The preliminary findings suggest that a combination of factors, including material, design, patient, and surgical factors, may contribute to the failure of total hip and knee arthroplasties. Mechanical trauma to the implants may be a contributing factor to hip and knee implant failure, as scratch marks and abrasions were common in the implants collected. The study has several limitations, which are clearly stated in the manuscript. Further research is needed to investigate these factors in more detail, using a larger number of implants and a wider population of surgeons, and to develop strategies to improve the success of these procedures.

The meniscus-guided coating (MGC) method was used to prepare well-aligned films of hybrid systems composed of the conjugated polymer poly{3,6-dithiophen-2-yl-2,5-di(2-decyltetra-decyl)-pyrrolo[3,4-c]pyrrole-1,4-dione-alt-thienylenevinylene-2,5-yl} (PDVT-10) and a photoresponsive small molecule dopant, dithienylperfluorocyclopentene (DTCP), at various concentrations in their open-ring form (DTCP-o) or closed-ring (DTCP-c) form. The structures of the coated films were characterized with polarized optical microscopy (POM), grazing-incidence X-ray diffraction (GIXRD), and atomic force microscopy (AFM). The DTCP can undergo reversible isomerization between a more twisted open-ring form and a more conjugated closed-ring form under UV and visible light, respectively. Both DTCP isomers were found to function as morphology-modulating additives that facilitate cooperative crystallization, an effect attributed to enhanced solution-phase molecular association, which impacts the packing of the polymer film. Organic field-effect transistors (OFETs) were fabricated from these films. The DTCP-c doping progressively enhanced charge transport, reaching the highest mobility of 2.44 cm2 V-1 s-1 at 10 wt %. Notably, 3 wt % DTCP-o, typically considered insulating molecule, increased PDVT-10 mobility from 2.12 to 3.23 cm2 V-1 s-1. This improvement is suggested to arise from the combined effects of precise molecular alignment by the MGC method and a favorable HOMO-HOMO energy level alignment predicted by DFT, enabling cooperative charge transfer despite the nominally insulating nature of the open-ring form. The photoswitchable DTCP provides a unique opportunity to optically modulate frontier molecular orbital energy levels, thereby opening up an avenue for designing electronic devices such as photocontrollable OFETs.

Sex crime investigations often rely on evidence involving minimal amounts of seminal material, making it necessary to use sensitive biomarkers to detect semen. Thanks to its high concentration, prostate-specific antigen (PSA) has been extensively utilized as a forensic marker, but there remains a lack of consensus regarding its diagnostic cut-off value. The technique proposed in this study applies a tiered diagnostic algorithm that combines a highly sensitive screening assay with a highly specific assay. The objective was to validate PSA quantification as a screening tool and establish an optimal cut-off value based on the receiver operating characteristic curve. A total of 460 forensic samples from sex crime investigations were analyzed for PSA quantification using electrochemiluminescence immunoassay (ECLIA). Optical microscopy was used as the reference standard to detect spermatozoa. Receiver operating characteristic curve analysis established a cut-off value of 0.085 ng/mL, with an area under the curve (AUC) of 0.848, a sensitivity of 82.8%, and a negative predictive value of 92.8%, showing diagnostic performance in line with international standards. The established cut-off value was lower than those previously documented and made it possible to increase the detection of potential semen in samples, doubling the number of positive identifications. In child victims, PSA detection is particularly relevant, given that endogenous secretion begins around the age of 9. Presence in children, even at minimal levels, may be indicative of adult male semen. These findings confirm the role of PSA as a sensitive and reliable screening test in forensic diagnostics.

Lactobacillus plantarum (L. plantarum) is a probiotic bacterium with diverse health-promoting effects. Recent evidence suggests that these benefits are mediated by extracellular vesicles (EVs) secreted by the bacterium; however, the underlying molecular mechanisms in the context of pathogenic inflammation remain poorly understood. In this study, we employed super-resolution stochastic optical reconstruction microscopy to elucidate the molecular mechanisms of action of L. plantarum EVs by monitoring alterations in the ultrastructural integrity of cellular organelles in human dermal fibroblasts exposed to Staphylococcus aureus EVs. Pathogenic EV exposure induced characteristic inflammatory changes in organelle morphology. Remarkably, both pre- and post-treatment with L. plantarum EVs restored organelle morphology in a concentration- and time-dependent manner. Cytokine profiling showed selective suppression of interleukin (IL)-6 and IL-8 while preserving IL-10, indicating targeted immunomodulation. We identified nicotinamide adenine dinucleotide (NAD⁺) as a key bioactive cargo, with exogenous NAD⁺ treatment reproducing both structural and cytokine-restorative effects. These findings establish NAD⁺-mediated organelle protection as a central mechanism through which probiotic EVs mitigate bacterial inflammation. By linking organelle integrity to inflammatory outcomes, our study highlights L. plantarum EVs as nanoscale therapeutic candidates for infection-driven inflammation.

Polyelectrolyte capsules (PEC) are hollow polymer particles fabricated by layer-by-layer (LbL) assembly of subsequently deposited polyelectrolytes of alternating charge. PECs, valued for their tunability and cargo encapsulation capabilities, are interesting for biomedical applications, underscoring the need for standardized fabrication and characterization techniques to optimize it for specific biomedical tasks. Here common protocols on how to synthesize and characterize such capsules are summarized. The fabrication of both, biodegradable and non-biodegradable capsules ranging in size from 800nm to 5μm is outlined. The entire preparation process-from the synthesis of sacrificial templates with diverse sizes and morphologies, to the controlled LbL deposition of polyelectrolyte shells and subsequent core dissolution is detailed. Here, calcium carbonate is selected as the sacrificial template of focus, owing to its high biocompatibility and loading capacity. Particular emphasis is placed on strategies for cargo loading, including co-precipitation and post-loading methods. Furthermore, the key characterization methods essential for confirming PEC formation-including size and zeta potential measurements (via dynamic light scattering), capsule concentration analysis (using optical or fluorescence microscopy), cargo encapsulation quantification (by UV-Vis spectroscopy or fluorescence analysis), and structural analysis (using transmission electron microscopy, TEM)-are highlighted and discussed. Finally, the review addresses current advantages and limitations in PEC fabrication, such as scalability and uniformity, and proposes future directions involving microfluidics, automation, and template design for the next generation of advanced biomedical applications.

Implantation of intracortical microelectrodes generates free iron species that exacerbate pro-inflammatory responses by producing reactive oxygen species through the Fenton reaction. This work reports a covalently grafted, two-layer poly(ethylene glycol)dimethacrylate (PEGDMA) hydrogel on polyimide-insulated Pt/Ir microwires for local delivery of the iron chelator deferasirox (DFO). The polyimide insulating layer was methacrylated to enable covalent anchoring of a PEGDMA550 interlayer, followed by a DFO-loaded PEGDMA3400 outer layer. Scanning electron microscopy and optical microscopy of the hydrogel-coated microwires revealed a uniform coating morphology with dispersed DFO aggregates embedded within the matrix. In buffer at 37 °C, DFO release followed diffusion-controlled kinetics and fell below the limit of detection by ultraperformance liquid chromatography by day 9. The iron-chelation properties of the DFO-loaded microwires were investigated using Fe(EDTA) as a free-iron mimic. When a high concentration of Fe(EDTA) was used (10 mM), the Fe(DFO)2 complex remained detectable for up to 19 days, which expands well beyond the detection limit of DFO under iron-free conditions (9 days). Energy-dispersive X-ray spectroscopy showed time-dependent iron accumulation within the hydrogel, consistent with in-matrix complexation that perturbs local transport and prolongs chelation efficacy. Collectively, the coating functions as a mechanically integrated, responsive reservoir whose pharmacokinetics are governed by the iron concentration rather than initial drug loading. By coupling chelation capacity to local iron availability, the presented hydrogel coating establishes a generalizable route to extend therapeutic lifetimes of functionalized chronic neural electrodes.

Polymer-based drug delivery systems offer robust opportunities to improve chemotherapy performance while mitigating systemic toxicity, a critical challenge in leukemia treatment. In this study, poly(ε-caprolactone) (PCL) microparticles were developed as carriers for the co-delivery of cytarabine (ARA-C), a frontline antileukemic agent, and a pecan-derived polyphenolic extract (PRE) as a complementary bioactive component. Microparticles were prepared by a double emulsion solvent evaporation method and formulated with varying drug and extract loadings. The systems were characterized in terms of morphology, particle size, colloidal properties, encapsulation efficiency, and chemical composition using optical microscopy, scanning electron microscopy, dynamic light scattering, zeta potential analysis, UV–Vis spectroscopy, Folin–Ciocalteu assay, and FTIR spectroscopy. In vitro release studies revealed sustained and formulation-dependent release profiles for both ARA-C and PRE, which were successfully fitted to kinetic models, indicating diffusion- and matrix-controlled release mechanisms. Additionally, preliminary cell viability assays using fibroblasts supported the cytocompatibility of the formulations. The results support the use of PCL-based microparticles as reproducible polymeric systems for the co-encapsulation and controlled release of cytarabine and polyphenol-rich extracts, contributing to the development of combination delivery approaches relevant to leukemia treatment.

Herein, we report a novel erlotinib (EH) -loaded calcium carbonate (CaCO3) tubular micromotor fabricated via an internal-filling strategy, achieving a high drug payload of 2.53 × 10- 1 2 mol per micromotor, which integrates three core functionalities in one system: targeted delivery of EH, pH-responsive release, and ultrasound-based tracking. The microtube structures (10 µm in diameter) are prepared by electrochemical deposition, followed by filling the EH@CaCO3 microparticle into the interior of the tubular motor. Distinct from the surface coating approach for drug immobilization, this internal-filling strategy enables substantially greater payloads. The EH@CaCO3 tubular micromotor shows favorable bubble and magnetic propulsion capabilities. Serving as a proof-of-concept for targeted anti-cancer drug delivery, these micromotors can transport drugs within microchips channel to the targeted position. Under acidic conditions, CaCO3 undergoes decomposition to release the encapsulated drug. Concurrently, the Zn-based inner structure of the tubular micromotor reacts with hydrogen ions (H+), leading to micromotor degradation and thereby facilitating rapid drug release. The as-released drug shows cell killing ability toward non-small cell lung cancer cells A549. Meanwhile, as the micromotors move in an acidic environment, the in situ generated bubbles can act as "ultrasonic contrast agents", thereby enabling real-time tracking of the micromotors. For potential in vivo applications, this facilitates the tracking of such motors in scenarios where optical microscopy is ineffective. The blood compatibility, coagulation function, and preliminary in vivo immune response evaluation all indicate that the system had good biosafety. This study provides a new idea for the development of a next-generation micro drug delivery platform with high drug loading, intelligent delivery, and real-time visualization.

Development and characterization of metformin hydrochloride hydrogels as potential wound dressings for diabetic foot ulcers.