Facile Synthesis of Copper(II)Immobilized on Magnetic Mesoporous Silica Microspheres for Selective Enrichment of Peptides for Mass Spectrometry Analysis

A non-targeting magnetic metal-organic framework probe for highly specific peptide-mediated precise disease monitoring

Alzheimer's disease (AD) is a universal neurodegenerative disease in older adults with incurable and progressive properties, urging for precise monitoring to perform timely treatment to delay its progression. Herein, we introduced a non-targeting magnetic metal-organic framework probe coupled with high-throughput mass spectrometry, creating a rapid screening strategy for highly specific peptides associated with AD. Notably, an elution-free extraction process was proposed, significantly reducing sample preprocessing time while simultaneously ensuring the efficient detection of captured peptides. Using this elution-free extraction process, high-quality peptide profiles were rapidly extracted from the hundreds of samples from both diseased and healthy individuals. By integrating machine learning algorithms, LC-MS/MS, and Uniprot database searching, we identified three specific serum endogenous peptides (m/z = 4215.41, 2884.77 and 2704.61) closely associated with AD. Remarkably, with the use of any single specific peptide, the AUC (Area Under the Curve) values can reach approximately 0.9 during monitoring AD. Moreover, integrating three specific biomarkers provides a robust basis for machine learning algorithms to build monitoring models, with AUC value up to 1.000. This work represents a substantial advancement in the development of peptide-specific precise monitoring approaches for complex diseases, serving as a catalyst for increased dedication to the molecular detection field.

Histidine modified Fe3O4 nanoparticles improving the ethanol yield and tolerance of Saccharomyces cerevisiae

Saccharomyces cerevisiae, the primary microorganism involved in ethanol production, is hindered by the accumulation of ethanol, leading to reduced ethanol production. In this study, we employed histidine-modified Fe3O4 nanoparticles (His-Fe3O4) for the first time, to the best of our knowledge, as a method to enhance ethanol yield during the S. cerevisiae fermentation process. The results demonstrated that exposing S. cerevisiae cells to Fe3O4 nanoparticles (Fe3O4 NPs) led to increased cell proliferation and glucose consumption. Moreover, the introduction of His-Fe3O4 significantly boosted ethanol content by 17.3% (p < 0.05) during fermentation. Subsequent findings indicated that the increase in ethanol content was associated with enhanced ethanol tolerance and improved electron transport efficiency. This study provided evidence for the positive effects of His-Fe3O4 on S. cerevisiae cells and proposed a straightforward approach to enhance ethanol production in S. cerevisiae fermentation. The mediation of improved ethanol tolerance offers significant potential in the fermentation and bioenergy sectors.

Biological Applications of Silica-Based Nanoparticles

Silica nanoparticles have been widely explored in biomedical applications, mainly related to drug delivery and cancer treatment. These nanoparticles have excellent properties, high biocompatibility, chemical and thermal stability, and ease of functionalization. Moreover, silica is used to coat magnetic nanoparticles protecting against acid leaching and aggregation as well as increasing cytocompatibility. This review reports the recent advances of silica-based magnetic nanoparticles focusing on drug delivery, drug target systems, and their use in magnetohyperthermia and magnetic resonance imaging. Notwithstanding, the application in other biomedical fields is also reported and discussed. Finally, this work provides an overview of the challenges and perspectives related to the use of silica-based magnetic nanoparticles in the biomedical field.

Nanoarchitectured prototypes of mesoporous silica nanoparticles for innovative biomedical applications

Despite exceptional morphological and physicochemical attributes, mesoporous silica nanoparticles (MSNs) are often employed as carriers or vectors. Moreover, these conventional MSNs often suffer from various limitations in biomedicine, such as reduced drug encapsulation efficacy, deprived compatibility, and poor degradability, resulting in poor therapeutic outcomes. To address these limitations, several modifications have been corroborated to fabricating hierarchically-engineered MSNs in terms of tuning the pore sizes, modifying the surfaces, and engineering of siliceous networks. Interestingly, the further advancements of engineered MSNs lead to the generation of highly complex and nature-mimicking structures, such as Janus-type, multi-podal, and flower-like architectures, as well as streamlined tadpole-like nanomotors. In this review, we present explicit discussions relevant to these advanced hierarchical architectures in different fields of biomedicine, including drug delivery, bioimaging, tissue engineering, and miscellaneous applications, such as photoluminescence, artificial enzymes, peptide enrichment, DNA detection, and biosensing, among others. Initially, we give a brief overview of diverse, innovative stimuli-responsive (pH, light, ultrasound, and thermos)- and targeted drug delivery strategies, along with discussions on recent advancements in cancer immune therapy and applicability of advanced MSNs in other ailments related to cardiac, vascular, and nervous systems, as well as diabetes. Then, we provide initiatives taken so far in clinical translation of various silica-based materials and their scope towards clinical translation. Finally, we summarize the review with interesting perspectives on lessons learned in exploring the biomedical applications of advanced MSNs and further requirements to be explored.

Fabrication of Fe3O4@poly(methyl methacrylate-co-glycidyl methacrylate) microspheres via miniemulsion polymerization using porous microspheres as templates for removal of cationic dyes

A novel and simple method was proposed to prepare monodisperse magnetic microspheres with controllable particle sizes and different functionalities.

An eco-friendly, low-cost, and automated strategy for phosphoproteome profiling

An automated, online analysis platform using a reusable phos-trap column helps reduce organic solvent, plastic consumables, waste, and labor costs in phosphoproteomic studies.

Ti4+-immobilized hierarchically porous zirconium-organic frameworks for highly efficient enrichment of phosphopeptides

Ti⁴⁺-immobilized hierarchically porous zirconium-organic frameworks (denoted as THZr-MOFs) was prepared for phosphopeptide enrichment. The THZr-MOFs showed high specific surface area of 185.28 m² g^-1, wide pore-size distribution of 3 ~ 20 nm, good chemical stability and excellent hydrophilicity. Introduction of hierarchical pores in MOFs not only facilitated the accessibility of phosphopeptides to the internal metal affinity sites and reduce their mass transfer resistance, but also increased the exposure sites of metal affinity interaction and binding energies of Zr and Ti elements. Benefited from these advantages, the THZr-MOFs showed high adsorption capacity (79.8 μg mg^-1) towards standard phosphopeptide. A low detection limit (0.05 fmol μL^-1) and high enrichment selectivity (β-casein/BSA with a molar ratio of 1:5000) were also obtained by MALDI-TOF MS. The THZr-MOFs were applied to analyze complex samples including nonfat milk, human serum, and HeLa cell lysate. In total, 1432 phosphopeptides derived from 762 phosphoproteins were identified from human HeLa cell lysate. Schematic representation of the application of Ti⁴⁺-immobilized hierarchically porous zirconium-organic frameworks (denoted as THZr-MOFs) in high-efficiency and selective enrichment of low-abundance phosphopeptides from the tryptic digest of human HeLa cell lysate.

Sample preparation considerations for surface and crystalline properties and ecotoxicity of bare and silica-coated magnetite nanoparticles

Magnetite (Fe₃O₄) nanoparticles (NPs) have widely used in various fields, including in medicine, due to their (super)paramagnetic properties. This requires a thorough evaluation of their possible hazardous effects. However, there is no standard procedure for the preparation of oxidation-prone NPs (such as magnetite) before subjecting them to biological assays. In this study we used Fe₃O₄ NPs (bare and silica-coated) as test samples to compare different preparation methods (ultrasound, centrifugation and filteration of NPs suspensions) based on X-ray and dynamic light scattering analysis and evaluation of microstructure and surface charge. After oxidation and functionalization, all samples retained their superparamagnetic behaviour. The toxicity of NP suspensions obtained by the methods described for Paramecium caudatum ciliates and Sinapis alba plants was evaluated.

The charge and surface reactivity of magnetite nanoparticles can be affected by the different separation methods leading to their toxicity changes.

Targeted immobilization of titanium (IV) on magnetic mesoporous nanomaterials derived from metal-organic frameworks for high-efficiency phosphopeptide enrichment in biological samples

A selectively modified porous metal/carbon nanocomposite was fabricated to enhance the enrichment of low-abundance phosphopeptides from biological samples. The carbon matrix derived from the metal-organic framework provides a suitable pore size to allow the diffusion of peptides, while the deliberately modified metal nanoparticles within the pores enhance their interaction with the phosphopeptides. This nanocomposite shows extremely high enrichment selectivity for phosphopeptides in the MALDI-TOF MS detection, even when the molar ratio of α-casein digests versus bovine serum albumin digests was up to about 1:20,000. By combining such nanocomposite with nano-LC-MS/MS, 4556 unique phosphopeptides were identified with high selectivity (95.2%) from HeLa cell extracts. Furthermore, phosphopeptides from prostate tissue digests were also determined. A total of 277 and 1242 phosphopeptides were identified from normal and tumor tissues of a patient with prostate cancer, respectively. This indicates that phosphorylation and prostate cancer can be related to each other.

Preparation, surface functionalization and application of Fe3O4 magnetic nanoparticles

This paper reviews recent developments in the preparation, surface functionalization, and applications of Fe₃O₄ magnetic nanoparticles. Especially, it includes preparation methods (such as electrodeposition, polyol methods, etc.), organic materials (such as polymers, small molecules, surfactants, biomolecules, etc.) or inorganic materials (such as silica, metals, and metal oxidation/sulfide, functionalized coating of carbon surface, graphene, etc.) and its applications (such as magnetic separation, protein fixation, magnetic catalyst, environmental treatment, medical research, etc.). In the end, some existing challenges and possible future trends in the field were discussed.

Isoniazid-functionalized Fe3O4 Magnetic Nanoparticles as a Green and Efficient Catalyst for the Synthesis of 3, 4-dihydropyrimidin-2(1H)-ones and their Sulfur Derivatives

BACKGROUND

A wide variety of dihydropyrimidins (DHPMs) exhibit pharmacological and biological activities. Herein, an efficient one-pot synthesis of some 3, 4-dihydropyrimidin-2(1H)-one derivatives is reported using Fe3O4 @SiO2-Pr-INH.

OBJECTIVE

Recently, several catalysts have been used to improve the Biginellis-reaction. However, some of these catalysts have imperfections. Herein, a convenient method for the synthesis of 3, 4-dihydropyrimidin- 2(1H)-ones and their sulfur derivatives using Fe3O4 @SiO2-Pr-INH is reported.

MATERIALS AND METHODS

Firstly, the catalyst was synthesized through a simple four-step method. The Fe3O4 MNPs were synthesized using the chemical co-precipitation method, coated with a layer of silica using TEOS, and then functionalized with CPTMS. Subsequently, a nucleophilic substitution of Cl by isoniazid resulted in the formation of the magnetic Fe3O4@SiO2-Pr-INH. After the preparation and characterization of Fe3O4@SiO2-Pr-INH, its catalytic activity was studied in the synthesis of 3, 4-dihydropyrimidin-2(1H)-one derivatives. Following the optimization of the reaction conditions, several 3, 4-dihydropyrimidin-2(1H)-one derivatives were synthesized by the reaction of ethyl acetoacetate or acetylacetone, thiourea or urea and aromatic aldehydes at 80 °C under solvent-free conditions.

RESULTS

Isoniazid-functionalized Fe3O4 magnetic nanoparticles (Fe3O4@SiO2-Pr-INH) were prepared using Fe3O4 with silica layer and their surface was modified with isoniazid. They were characterized successfully by infrared spectroscopy, powder X-ray diffraction, scanning electron microscopy, energy-dispersive X-ray spectroscopy and were used for the synthesis of some 3, 4-dihydropyrimidin-2(1H)-one derivatives as catalysts. Aromatic aldehydes with electron-donating or electron-withdrawing groups afforded 3, 4- dihydropyrimidin-2(1H)-ones and their sulfur derivatives in good to excellent yields in short reaction times.

CONCLUSION

Isoniazid-functionalized Fe3O4 magnetic nanoparticles (Fe3O4@SiO2-Pr-INH) were used as an efficient catalyst for Biginelli-type synthesis of 3, 4-dihydropyrimidin-2(1H)-ones and 3, 4-dihydropyrimidin- 2(1H)-thiones in good to excellent yields and short reaction times. It is noteworthy that this method has several advantages such as simple experimental procedures, the absence of solvent, environmentally benign process, stability and reusability of the catalyst.

Boronic acid-functionalized mesoporous magnetic particles with a hydrophilic surface for the multimodal enrichment of glycopeptides for glycoproteomics

Boronic acid-functionalized mesoporous magnetic particles with a hydrophilic surface for multimodal enrichment of glycopeptides for glycoproteomics.

One-step separation of the recombinant protein by using the amine-functionalized magnetic mesoporous silica nanoparticles; an efficient and facile approach

The separation process is the main stage of recombinant production. With the advancement of nanotechnology and the development of magnetic nanoparticles, these structures are increasingly used in different applications. In the present study, we produced the recombinant human growth hormone from Pichia pastoris and for protein separation provided the surfaces similar to chromatographic columns on the surface of magnetic nanoparticles. For this purpose, using a co-precipitation method, the core of Fe₃O₄ was prepared and coated by silica. To increase the protein availability, silica mesoporous formation and its amine functionalization were performed. The specific surface area and the pore size were determined 78.3189 m²/g and 7.44 nm. After the magnetic separation, the sample loading in SDS gel shows a reduction in protein band and the protein absorption at a wavelength of 280 nm. Finally, we evaluate the ability of amine functionalized nanoparticles for protein separation that demonstrate the adsorption capacity significantly increased compare with silica-coated nanoparticles. The amine functionalized nanoparticles provide the maximum adsorption capacity of 235.21 μg/mg and after the elution, protein concentration determined 476 mg/L. This work indicates the functionalized magnetic mesoporous silica nanoparticles can be used as the best candidate for the separation of different biological macromolecules.

Preparation and Study of the Antibacterial Applications and Oxidative Stress Induction of Copper Maleamate-Functionalized Mesoporous Silica Nanoparticles

Mesoporous silica nanoparticles (MSNs) are an interesting class of nanomaterials with potential applications in different therapeutic areas and that have been extensively used as drug carriers in different fields of medicine. The present work is focused on the synthesis of MSNs containing a maleamato ligand (MSN-maleamic) and the subsequent coordination of copper(II) ions (MSN-maleamic-Cu) for the exploration of their potential application as antibacterial agents. The Cu-containing nanomaterials have been characterized by different techniques and the preliminary antibacterial effect of the supported maleamato-copper(II) complexes has been tested against two types of bacteria (Gram positive and Gram negative) in different assays to determine the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC). The biological results showed a moderate antibacterial activity against Escherichia coli which motivated a more detailed study of the antibacterial mechanism of action of the synthesized maleamate-containing nanosystems and whose findings showed oxidative stress generation in bacterial cells. All the prepared nanomaterials were also tested as catalysts in the "solvent free" selective oxidation of benzyl alcohol, to observe if there is a potential correlation between the catalytic oxidation capacity of the materials and the observed oxidative stress in bacteria. This may help in the future, for a more accurate rational design of antibacterial nanosystems, based on their observed catalytic oxidation activity.

Rational synthesis of hierarchical magnetic mesoporous silica microspheres with tunable mesochannels for enhanced enzyme immobilization

Hierarchical magnetic mesoporous silica microspheres (MMSMs) with a core-shell structure have been fabricated through an improved water/oil biphase synthesis strategy. We firstly reported that the mesopore size can be readily tuned from 6.1 to 11.4 nm by the synergistic effect of surfactant concentration and an amphiphilic agent, thus holding a bright future in many possible applications.

Synthesis of zwitterionic hydrophilic magnetic mesoporous silica materials for endogenous glycopeptide analysis in human saliva

A novel zwitterionic hydrophilic magnetic mesoporous silica was prepared for endogenous glycopeptide enrichment prior to MS analysis. For the first time, the material was successfully applied in capturing endogenous glycopeptides from human saliva, indicating great potential of this strategy for glycopeptidome analysis.

Room-temperature synthesis of core–shell structured magnetic covalent organic frameworks for efficient enrichment of peptides and simultaneous exclusion of proteins

Core–shell structured Fe₃O₄@COFs were synthesized and used as a new absorbent for efficient enrichment of peptides and simultaneous exclusion of proteins.

Simple synthesis of multiple length-scale structured Nb2O5 with functional macrodomain-integrated mesoporous frameworks

Multiple length-scale structured Nb₂O₅ was synthesized by the interplay of macro- and microphase separation and macro-/mesostructures exhibit light-scattering capability and high surface areas.

Palladium modified porous silicon as multi-functional MALDI chip for serum peptide detection

Interest in using mesoporous materials for peptidomic research has increased recently.

Probing the Microporous Structure of Silica Shell Via Aggregation-Induced Emission in Au(I)-Thiolate@SiO2 Nanoparticle

An efficient method to investigate the window size of the silica shell generated via the classical Stöber method is reported by making use of the unique aggregation-induced emission property of Au(I)-thiolate complexes, which can precisely probe the porosity of the silica shell in Au(I)-thiolate@SiO₂ nanoparticles.

Multi-dimensional on-particle detection technology for multi-category disease classification

Multidimensional on-particle detection technology expands the capacity of serum peptide information and reveals disease biomarkers for future clinical diagnosis.

Monodisperse magnetic mesoporous silica microspheres facilitate the studies of gastric cancer-specific peptides in sera

The prognosis of gastric cancer remains poor despite the recent improvements in therapies.

Highly selective enrichment of baicalin in rat plasma by boronic acid-functionalized core-shell magnetic microspheres: Validation and application to a pharmacokinetic study

To the best of our knowledge, this study is the first to successfully apply a novel, highly selective enrichment technique based on boronic acid-functionalized core-shell magnetic microspheres (BA-Fe3O4@SiO2-Au@mSiO2) with a large surface area and uniform pore size, to determine the baicalin concentration in rat plasma by HPLC. By taking advantage of the special interaction between boronic acid and baicalin under alkaline conditions, as well as the microspheres' size exclusion ability, baicalin was selectively extracted from protein-rich biosamples, such as plasma, without any other pretreatment procedure except for a 10-min vortexing step. BA-Fe3O4@SiO2-Au@mSiO2 microsphere-adsorbed baicalin was straightforwardly and rapidly isolated from the matrix using a magnet. Baicalin was subsequently eluted from the microspheres under acidic conditions for 2min for further HPLC analysis. The extraction conditions, such as the amount of microspheres added, adsorption time, adsorption pH, and elution time and pH, were also determined. Furthermore, method validation, including the linear range, detection limit, precision, accuracy, and recovery, were determined. This newly developed method based on BA-Fe3O4@SiO2-Au@mSiO2 microspheres is a simple, accurate, selective, and green analytical preparatory technique for analyzing baicalin in rat plasma. This study will be further novel research on the analysis of complex plasma samples and the pharmacokinetics of drugs similar to baicalin.

Designed synthesis of aptamer-immobilized magnetic mesoporous silica/Au nanocomposites for highly selective enrichment and detection of insulin

We designed and synthesized aptamer-immobilized magnetic mesoporous silica/Au nanocomposites (MMANs) for highly selective detection of unlabeled insulin in complex biological media using MALDI-TOF MS. The aptamer was easily anchored onto the gold nanoparticles in the mesochannels of MMANs with high capacity for highly efficient and specific enrichment of insulin. With the benefit from the size-exclusion effect of the mesoporous silica shell with a narrow pore size distribution (∼2.9 nm), insulin could be selectively detected despite interference from seven untargeted proteins with different size dimensions. This method exhibited an excellent response for insulin in the range 2-1000 ng mL(-1). Moreover, good recoveries in the detection of insulin in 20-fold diluted human serum were achieved. We anticipate that this novel method could be extended to other biomarkers of interest and potentially applied in disease diagnostics.

Facile synthesis of FeIII–tannic acid film-functionalized magnetic silica microspheres for the enrichment of low-abundance peptides and proteins for MALDI-TOF MS analysis

Fe₃O₄@SiO₂@FTA microspheres were prepared for efficient and fast enrichment of peptides and proteins.

Preparation of mesoporous SiO2@azobenzene–COOH chemoselective nanoprobes for comprehensive mapping of amino metabolites in human serum

mSiO₂@azobenzene–COOH chemoselective nanoprobes were developed for comprehensive mapping of amino metabolites in complex biological samples with high specificity and sensitivity.