Search Results (191)

Protein crystal nucleation remains difficult to predict and control and is still a critical issue in structural biology, protein crystal formulations, and crystal engineering. Heterogeneous nucleants can regulate protein crystallization by providing solid interfaces, enriching protein molecules, and stabilizing prenucleation aggregates; however, their dominant action stage, particle-size effect, and interfacial interaction mechanism remain unclear. In this study, hen egg white lysozyme (HEWL) was selected as a model protein, and silica nanoparticles (SNPs) with average diameters of 80, 120, and 200 nm were prepared using the modified Stöber method. Under a constant total particle surface area, the effects of SNPs on HEWL crystallization, prenucleation aggregation, interfacial adsorption, and subsequent crystal growth were systematically investigated. The results showed that, under 30 mg·mL⁻¹ HEWL and 0.6 M NaCl conditions, all SNPs shortened the apparent induction time, with 200 nm SNPs showing the strongest effect. In contrast, 80 nm SNPs produced the largest crystal size at the fixed observation time of 72 h, suggesting that crystal size within a fixed incubation period is jointly affected by nucleation rate, nucleus number, local solute consumption, and subsequent crystal growth. Under low protein concentration and low NaCl concentration conditions, SNPs promoted crystal formation in systems with weak spontaneous nucleation. Zeta potential, UV-Vis, fluorescence, FT-IR, CD, and DLS results suggested that SNPs interacted with HEWL at the interface and promoted apparent aggregation behavior, whereas polarized optical microscopy indicated no detectable influence on the later linear growth of visible crystals. These results suggest that SNPs mainly affect processes before visible crystal formation and provide insight into their application as heterogeneous nucleants for protein crystallization. Full article

In medicine, nanoparticles are used for various purposes, including theranostics, imaging, diagnostics, drug delivery, tissue regeneration and targeted cancer treatments, and to minimize the harmful side effects associated with conventional therapies. Target-specific biomolecules, such as silica nanoparticles (SiNPs) labeled with metallic radionuclides, are becoming increasingly popular. The choice of radionuclide is based on its nuclear properties. Silica has several advantages for nanoparticle synthesis, including high biocompatibility, the capacity for drug encapsulation due to its porous structure, and the potential for extensive surface functionalization, including radiolabeling for imaging and therapeutic applications. A radionuclide can be attached to a silica nanoparticle either directly or through the use of chelators or polymers. Additionally, the capability to encapsulate therapeutic agents within such systems offers significant potential for the development of targeted therapies. This study aims to provide a comprehensive overview of recent developments in the radiolabeling of silica-based nanoparticles, with a focus on their application in nuclear medicine, particularly in diagnostic imaging and targeted radionuclide therapy. Theranostics employs a range of imaging modalities to guide and monitor therapeutic interventions. Principal techniques include positron emission tomography (PET), single-photon emission computed tomography (SPECT), magnetic resonance imaging (MRI), and Optical Imaging (such as fluorescence and bioluminescence). These imaging methods enable precise visualization of pathological sites, facilitate tracking of therapeutic agent distribution, and permit real-time assessment of treatment efficacy. Full article

A method for synthesizing theranostic nanoparticles (NPs) based on a silica core, a mercapto spacer, a cardioprotector, and a fluorescent dye has been developed. The total amount of grafted mercapto groups was 0.079 mmol/g. The amount of accessible mercapto groups on the surface of the synthesized particles, calculated using the Kunkel, Buckley, and Gorin method, was 0.025 mmol/g. A total of 0.031 mmol/g of adenosine and 0.0087 mmol/g of indocyanine green are grafted onto the mercapto spacer. Both substances are presumably attached via hydrogen bonding to the modified silica nanoparticle in a ratio of 60/40% for adenosine and indocyanine green, respectively. The resulting nanoparticles exhibit no hemolytic activity. Intensive adenosine release occurs within 90 min and continues for up to 24 h. Based on biodistribution, significant accumulation of the nanoparticles occurs in the liver. Full article

Hydrogen peroxide (H₂O₂) plays a very vital role in industrial and biological processes, but its high concentration may cause health hazards. Therefore, accurate detection of H₂O₂ is crucial for chemical and biological sensing applications. In this work, a ratiometric fluorescent probe was developed using a core–shell structural silica nanoparticle for the detection of H₂O₂. Firstly, a silica core structure with red fluorescence emission was constructed by encapsulating a Schiff base compound (SD). Afterwards, a mesoporous silica shell was fabricated, and the AIE featured fluorophore with a H₂O₂ response character was covalently linked on the surface of the mesoporous shell layer. As recognition sites on the shell, blue-emitting TB molecules specifically identified H₂O₂ through their phenylboronic acid ester group. The blue fluorescence of core–shell structural nanoprobes would be quenched in the presence of H₂O₂, while red fluorescence remained unchanged, ensuring the high sensitivity and specificity of the ratio sensing. This design has demonstrated significant potential for the reliable monitoring of hydrogen peroxide in biological and environmental applications. Full article

Monitoring the concentration of doxorubicin (DOX) was critical for tumor treatment, but existing methods failed to cross cell membrane. Here, an electrochemical platform for intracellular DOX detection in MCF-7 cells based on membrane-permeation strategy was developed. A modified gold electrode was prepared via electrodepositing AuNPs and assembling SH-DNA. Concurrently, the silica nanosphere/gold nanocluster-circular transmembrane peptide (SiO₂/AuNCs-iRGD) composite nanoparticles with membrane permeability, tumor targeting, and imaging capability were synthesized. After co-incubation of SiO₂/AuNCs-iRGD with MCF-7 cells and DOX, followed by co-incubation with the DNA-modified electrode, intracellular DOX intercalated into the DNA backbone, and redox-generated electrons were transferred to the electrode to produce a concentration-correlated electrochemical signal. The modification of the electrode, the morphology of the composite nanoparticles and the detection process were characterized by means of SEM, TEM, CV, EIS, DPV, fluorescence spectroscopy and laser confocal imaging. Under the optimized conditions, the proposed method exhibited a wide detection range of 0.05–300 μmol/L, with a detection limit of 0.01 μmol/L. Moreover, the modified electrode demonstrated satisfactory regenerability, and the proposed method showed excellent reproducibility and stability. The development platform could offer a new strategy for real-time assessment of drug concentration within cultured breast cancer cells in vitro. Full article

The manuscript describes an optical sensing microplate for the high-throughput screening of imidazolinone herbicides in soil extracts. As far as we know, imprinted proteins (IPs) specific to imidazolinone herbicides have not been synthesized and used as a recognition element for their solid-phase extraction before. Imprinted bovine serum albumin (BSA) and glucose oxidase (GOx) were synthesized in the presence of imazamox as a template and then these IPs were immobilized at the bottom of microplate wells. The sorption capacity (Q) of aminated silica nanoparticles modified by IPs (IP–BIS) was 6.38 mg g⁻¹ while the imprinting factor ($IF$) equaled 2.6. The concentration of imazamox was determined by a “turn-off” solid-phase assay using alloyed CdZnSeS/ZnS quantum dots (QDs) as a component of fluorescent substrate. Alloyed CdZnSeS/ZnS QDs were stabilized in an aqueous phase by positively charged cysteamine that, as far we know, had not been used as this type of ligand before. Our method allows for determining the concentration of imazamox in the range of 0.5–9.2 μg mL⁻¹, with a limit of quantification limit of quantitation (LOQ) equal to 0.45 μg mL⁻¹ The sensing microplate enables parallel detection of up to 96 samples containing herbicides using standard fluorescence microplate readers or smartphones. The paper describes how such sensing microplates can be used for the analysis of artificially contaminated soil samples. The proposed approach combines pre-concentration of analyte at the IPs with its subsequent determination on a single analytical platform, thus allowing for both highly sensitive determination in laboratory conditions and mass screening in the field. Full article

Recent advancements in nanotechnology have led to the development of multifunctional nanoplatforms that significantly enhance both cancer diagnosis and treatment. Gold-based nanoparticles, such as peptide-functionalized nanostructures and PEG-coated nanorods, offer improved tumor targeting, multimodal imaging (including photoacoustic and fluorescence), and effective photothermal therapy. Similarly, ultrafine iron oxide nanoprobes provide superior tumor imaging, while silver-based nanoparticles exhibit rapid systemic circulation, near-infrared fluorescence, and powerful photothermal properties. Titanium-based nanoplatforms enable a combination of therapies and advanced imaging methods. On the therapeutic side, polymeric nanoparticles (PNPs), silica-based platforms, PEG-based nanoparticles, and graphene oxide-based systems each offer unique advantages for targeted drug delivery and theranostics. PNPs, with tunable size, shape, and surface chemistry, enable controlled drug release and reduced side effects, while silica-based nanoplatforms improve tumor targeting and imaging. PEG-based nanoparticles enhance drug release and tumor penetration, and graphene oxide-based systems facilitate subcellular targeting and synergistic therapies. Collectively, these innovations are paving the way for more efficient, precise, and safer cancer therapies, leading to improved clinical outcomes. Full article

Folate receptor alpha is expressed at low levels in normal tissues, but is elevated in aggressive breast cancer types and can be utilized for targeted nanoparticle delivery. Hence, we prepared a hybrid nanocarrier based on in-house synthesized mesoporous silica nanoparticles (MSNs) which were further lipid-coated and reinforced with folic acid (FA). Thorough physicochemical evaluation was performed including dynamic light scattering (DLS), powder x-ray diffraction (PXRD), thermogravimetric analysis (TGA), and nitrogen physisorption. In vitro dissolution of the model drug doxorubicin was carried out in release media with pH 7.4 and pH 5.5. The cytotoxic potential and cellular uptake were investigated in MCF-7 breast cancer cells via the MTT assay, doxorubicin fluorescence measurement, and microscopy. The potential amelioration of doxorubicin’s cardiotoxicity was evaluated in vitro on the H9c2 cell line. The results showed MSNs with significant pore volume (1.38 cm³/g) and relatively small sizes (98.05 ± 1.34 nm). The lipid coat and FA attachment improved the physicochemical stability and sustained release pattern over 24 h. MSNs were non-toxic, while when doxorubicin-loaded, they caused moderate cytotoxicity. The highest cytotoxic activity was observed with folate-functionalized, doxorubicin-loaded nanoparticles (NPs). Even though non-loaded folate-functionalized NPs exhibited significant cytotoxicity, their physical mixture with doxorubicin was inferior in MCF-7 cytotoxicity as opposed to the corresponding loaded nanocarrier. Fluorescence-based quantification showed a higher intracellular accumulation of doxorubicin when delivered via NPs. These results demonstrate the potential to use folate-functionalized NPs as carriers for doxorubicin delivery in breast cancer cells. Its cardiotoxicity was significantly reduced in the case of loading onto the folic acid-functionalized lipid-coated MSNs. All these findings provide a promising proof-of-concept, although further experimental validation, particularly regarding targeting selectivity and safety, is required. Full article

Multimodal nanocomposites that combine optical and magnetic functionalities are of great interest for applications such as imaging and temperature sensing. Ternary CuInS₂ (CIS)-based quantum dots (QDs) offer low toxicity, strong near-infrared (NIR) emission, and high photostability, making them promising for optical nanothermometry and imaging. In this study, CIS QDs were synthesized using an aqueous cysteine-mediated approach. Manganese ferrite (MnFe₂O₄) nanoparticles were prepared as the magnetic component due to their non-toxicity and superparamagnetic properties. To integrate both functionalities, QDs and magnetic nanoparticles (MNPs) were encapsulated in silica and then combined to form multimodal CIS/MnFe₂O₄/SiO₂ nanocomposites. The structure and morphology of the materials were characterized by TEM and XRD, while their optical properties were examined using UV–Vis, photoluminescence (PL) spectroscopy. This design ensured optical isolation, preventing fluorescence quenching while maintaining colloidal stability. The obtained composites exhibited PL in the NIR region and a thermosensitivity of 2.04%/°C. TEM analysis confirmed uniform silica shell formation and successful integration of both components within the composite. The materials also retained the superparamagnetic behavior of MnFe₂O₄, making them suitable for combined optical and magnetic functionalities. These results demonstrate the potential of CIS/MnFe₂O₄/SiO₂ nanocomposites as multifunctional platforms for optical imaging, temperature monitoring, and magnetically modulated effects. Full article

Fluorescent nanoprobes operating in the NIR-II window have gained considerable attention for biomedical imaging because of their deep-tissue penetration, reduced scattering, and high spatial resolution. Their tunable optical behavior, flexible surface chemistry, and capacity for multifunctional design enable sensitive detection and targeted visualization of biological structures in vivo. This review highlights recent advances in the design and optical engineering of four widely studied NIR-II nanoprobe families: quantum dots, carbon dots, upconversion nanoparticles, and dye-doped silica nanoparticles. These materials were selected because they offer well-defined architectures, controllable emission properties, and substantial mechanistic insight supporting discussions of imaging performance and translational potential. Particular focus is placed on emerging strategies for activatable, targeted, and ratiometric probe construction. Recent efforts addressing biosafety, large-scale synthesis, optical stability, and early preclinical validation are also summarized to clarify the current progress and remaining challenges that influence clinical readiness. By outlining these developments, this review provides an updated and focused perspective on how engineered NIR-II nanoprobes are advancing toward practical use in biomedical imaging and precision diagnostics. Full article

Among the many nanomaterials studied for biomedical uses, silica and gold nanoparticles have gained significant attention because of their unique physical and chemical properties and their compatibility with living tissues. Mesoporous silica nanoparticles (MSNs) have great stability and a large surface area, while gold nanoparticles (AuNPs) display remarkable optical features. Both types of nanoparticles have been widely researched for their individual roles in drug delivery, imaging, biosensing, and therapy. When combined with gadolinium (Gd), a common contrast agent, these nanostructures provide improved imaging due to gadolinium’s strong paramagnetic properties. This study focuses on incorporating gold nanoparticles and gadolinium into a silica matrix to develop a theranostic system. Various analytical techniques were used to characterize the nanocomposites, including infrared spectroscopy (FTIR), ultraviolet-visible spectroscopy (UV-Vis), thermogravimetric analysis (TGA), nitrogen adsorption, scanning electron microscopy (SEM), dynamic light scattering (DLS), X-ray fluorescence (XRF), X-ray diffraction (XRD), vibrating sample magnetometry (VSM), and neutron activation analysis (NAA). Techniques like XRF mapping, XANES, nitrogen adsorption, SEM, and VSM were crucial in confirming the presence of gadolinium and gold within the silica network. VSM and EPR analyses confirmed the attenuation of the saturation magnetization for all nanocomposites. This validates their potential for biomedical applications in diagnostics. Moreover, activating gold nanoparticles in a nuclear reactor generated a promising radioisotope for cancer treatment. These results indicate the potential of using a theranostic nanoplatform that employs mesoporous silica as a carrier, gold nanoparticles for radioisotopes, and gadolinium for imaging purposes. Full article

The synthesis of lanthanide fluorescent nanoparticles and the investigation of their fluorescence sensing applications have attracted a great deal of attention in materials science over the past decades. In this study, we designed and synthesized a core–shell fluorescent nanoparticle based on dual-center emission from the europium and terbium complexes, and demonstrated its application as a ratiometric fluorescence sensor for the detection of 2,6-pyridinedicarboxylic acid (DPA). The europium complex is embedded in the inner core, providing a stable fluorescence signal at 617 nm, while the terbium complex is positioned in the outer shell and exhibits a fluorescence “Turn-ON” response at 545 nm upon interaction with DPA molecules. The fluorescence intensity ratio F₅₄₅/F₆₁₇ exhibits a sensitive response to the DPA concentration. Experimental results demonstrate that the as-prepared SiO₂@Eu@SiO₂@Tb nanoparticle exhibits a linear response in the DPA concentration range of 10–100 μM, with a detection limit (LOD) of 1.38 μM and well selectivity for DPA sensing. This strategy offers new insights into the development of novel lanthanide-based ratiometric fluorescence sensors. Full article

Developments of nanostructured materials have a significant impact in various areas, such as energy technology and biomedical use. Examples include solar cells, energy management, environmental control, bioprobes, tissue engineering, biological marking, cancer diagnosis, therapy, and drug delivery. Currently, researchers are designing multifunctional nanodrugs that combine in vivo imaging (using fluorescent nanomaterials) with targeted drug delivery, aiming to maximize therapeutic efficacy while minimizing toxicity. These fascinating nanoscale “magic bullets” should be available in the near future. Inorganic nanovehicles are flexible carriers to deliver drugs to their biological targets. Most commonly, mesoporous nanostructured silica, carbon nanotubes, gold, and iron oxide nanoparticles have been thoroughly studied in recent years. Opposite to polymeric and lipid nanostructured materials, inorganic nanomaterial drug carriers are unique because they have shown astonishing theranostic (therapy and diagnostics) effects, expressing an undeniable part of future use in medicine. This review summarizes research from development to the most recent discoveries in the field of nanostructured materials and their applications in drug delivery, including promising metal-based complexes, platinum, palladium, ruthenium, titanium, and tin, to tumor cells and possible use in theranostics. Full article

(1) Background: The chorioallantoic membrane (CAM) model has the potential to contribute to the development of personalized medicine based on individual cancer patients. We previously established the CAM model using patient-derived CIC-DUX4 sarcoma cells. We also used the CAM model for characterization and a comparison with the mouse model by examining the tumor accumulation of small-size, highly dispersive mesoporous silica nanoparticles (MSNs). (2) Method: In this study, we transplanted a variety of cancer cell lines, including patient-derived osteosarcoma (OS) and extraskeletal osteosarcoma (ESOS) cells. Patient-derived OS, ESOS and other cell lines were transplanted onto CAMs. The proliferation of cancer cells within CAM tumors was confirmed using H&E staining. For the comparison of the CAM and mouse models, rhodamine B-labeled MSNs were administered intravenously to CAMs and to xenograft mice. Tumor accumulation was evaluated by examining fluorescence and by confocal microscopy. The biodistribution of MSNs was examined by measuring the Si content by ICP. (3) Results: H&E staining demonstrated the proliferation of cancer cells of OS, ESOS and others on CAMs. While growth patterns and morphologies varied among different cancer types, H&E staining confirmed the establishment of tumors. As for the tumor accumulation, both the CAM and mouse models showed that MSNs were selectively accumulated in the tumors in both the CAM and mouse models. (4) Conclusions: We have expanded the range of CAM models by using a variety of cancer cells, including patient-derived cell lines. We also report that the small-size, highly dispersive MSNs exhibit excellent tumor accumulation in both the CAM and mouse models. These results point to the usefulness of the CAM model for patient-derived cancer cells as well as for evaluating drug carriers for tumor targeting. Full article

Prostate cancer is the most common tumor in men in developed countries and it often responds poorly to conventional treatments. Monoclonal antibody (MoAb) therapy, for this pathology, has grown tremendously in the past decades, exploiting naked and conjugated antibodies to cytotoxic payloads to form antibody drug conjugates (ADCs). Several studies have been carried out conjugating biomolecules against prostate-specific membrane antigen (PSMA), highly expressed in this tumor, to cytotoxic drugs. Nano-based formulations show high potential in targeted drug delivery to enhance the bioavailability of drugs. Our research aimed to evaluate the feasibility of setting up a nanoparticle-based multimodal tool for targeted drug delivery, describing the step-by-step approach and to perform a first screening of these fluorescent PEGylated silica nanoparticles employed in selective cancer cell targeting and killing. These nanoparticles featured a core–shell structure to contemporarily conjugate the antibody and the cytotoxic payload monomethyl auristatin E (MMAE) using a step-by-step approach. We compared the cytotoxic effect of this multimodal nanotool near the antibody-MMAE and free MMAE. We found a lower cytotoxicity effect of the nanoparticle-based construct compared to free drugs, likely because of the preservation of the previously observed receptor-mediated endocytosis. Nanomedicine is confirmed as a powerful alternative to organic drug delivery systems, even if some aspects, such as drug loading efficacy, release, scalable manufacturing and long-term stability, need to be deepened. Full article