Design and fabrication of highly hydrophilic magnetic material by anchoring L-cysteine onto chitosan for efficient enrichment of glycopeptides

Design of magnetic polyethyleneimine-fluorescein isothiocyanate composites toward efficient enrichment of phosphopeptides

Phosphoproteins maintain the normal metabolic activity of the organisms. Direct phosphopeptides detection is difficult to be realized by mass spectroscopy (MS) due to the low ionization efficiency, low abundance of phosphopeptides and interferences of complicated biological fluids. In the present work, a magnetic composite material was prepared by combining polyethyleneimine (PEI) and fluorescein isothiocyanate (FITC) focusing on phosphopeptides enrichment. Fourier-transform infrared spectroscopy, thermogravimetry analysis, X-ray photoemission spectroscopy, X-ray diffraction and UV-vis spectrometry measurement results confirmed the successful synthesis of Fe3O4@PEI@FITC material. FITC was facilely connected with PEI, and the two motifs endowed the efficient enrichment capacity of phosphopeptides by simple regulation of pH. The Fe3O4@PEI@FITC material was applied to the detection of phosphopeptides from real samples, implying that it can serve as an applicable platform for phosphoproteomics analysis.

Advanced functional materials as reliable tools for capturing food-derived peptides to optimize the peptidomics pre-treatment enrichment workflow

Peptidomics strategies with high throughput, sensitivity, and reproducibility are key tools for comprehensively analyzing peptide composition and potential functional activities in foods. Nevertheless, complex signal interference, limited ionization efficiency, and low abundance have impeded food-derived peptides' progress in food detection and analysis. As a result, novel functional materials have been born at the right moment that could eliminate interference and perform efficient enrichment. Of note, few studies have focused on developing peptide enrichment materials for food sample analysis. This work summarizes the development of endogenous peptide, phosphopeptide, and glycopeptide enrichment utilizing materials that have been employed extensively recently: organic framework materials, carbon-based nanomaterials, bio-based materials, magnetic materials, and molecularly imprinted polymers. It focuses on the limitations, potential solutions, and future prospects for application in food peptidomics of various advanced functional materials. The size-exclusion effect of adjustable aperture and the modification of magnetic material enhanced the sensitivity and selectivity of endogenous peptide enrichment and aided in streamlining the enrichment process and cutting down on enrichment time. Not only that, the immobilization of metal ions such as Ti4+ and Nb5+ enhanced the capture of phosphopeptides, and the introduction of hydrophilic groups such as arginine, L-cysteine, and glutathione into bio-based materials effectively optimized the hydrophilic enrichment of glycopeptides. Although a portion of the carefully constructed functional materials currently only exhibit promising applications in the field of peptide enrichment for analytical chemistry, there is reason to believe that they will further advance the field of food peptidomics through improved pre-treatment steps.

Construction of a hydrophilic porphyrin-based MOF@COF hybrid via post-synthetic modification for N-glycopeptides analysis in human serum

A hybrid material, M@C-Br@GMA@Glu, consisting of a porphyrin-based metal-organic framework-covalent organic framework (MOF@COF), has been meticulously synthesized using a post-synthetic modification approach. This advanced material has demonstrated exceptional effectiveness in glycopeptide enrichment, characterized by an impressively low detection limit (0.2 fmol μL-1), high selectivity (1 : 2000), and loading capacity for glycopeptides (100 mg g-1). In practical applications with complex biological samples, 210 glycopeptides associated with 87 glycoproteins from the serum of the healthy group, and 156 glycopeptides related to 85 glycoproteins from the serum of cervical cancer were identified after enrichment with M@C-Br@GMA@Glu. Subsequent genetic ontology analysis has elucidated the relationship between cervical cancer and glycosylation, focusing on biological processes such as complement activation, innate immune response mechanisms, and the structural dynamics of the extracellular matrix. The collective findings not only validate the material's proficiency in the sensitive and selective enrichment of glycopeptides, but also underscore its potential in biomarker discovery applications.

Polyoxometalate functionalized magnetic metal-organic framework with multi-affinity sites for efficient enrichment of phosphopeptides

The reasonable design of metal-organic framework (MOF)-derived nanomaterial has important meaning in increasing the enrichment efficiency in the study of protein phosphorylation. In this work, a polyoxometalate (POM) functionalized magnetic MOF nanomaterial (Fe3O4@MIL-125-POM) was designed and fabricated. The nanomaterial with multi-affinity sites (unsaturated metal sites and metal oxide clusters) was used for the enrichment of phosphopeptides. Fe3O4@MIL-125-POM had high-efficient enrichment performance towards phosphopeptides (selectivity, a mass ratio of bovine serum albumin/α-casein/β-casein at 5000:1:1; sensitivity, 0.1 fmol; satisfactory repeatability, ten times). Furthermore, Fe3O4@MIL-125-POM was employed to enrich phosphopeptides from non-fat milk digests, saliva, serum, and A549 cell lysate. The enrichment results illustrated the great potential of Fe3O4@MIL-125-POM for efficient identification of low-abundance phosphopeptides.

Triazine-structured covalent organic framework nanosheets with inherent hydrophilicity for the highly efficient and selective enrichment of glycosylated peptides

Protein glycosylation plays a crucial role in various biological processes and is related to various diseases. Highly specific enrichment of glycopeptides before mass spectrometry detection is crucial for comprehensive glycoproteomic analysis. However, it still remains a great challenge due to the absence of affinity materials with excellent enrichment efficiency. In this work, a triazine structure linked by a -NH- bond of two-dimensional (2-D) covalent organic framework (COF) nanosheets was synthesized as an affinity adsorbent for the selective capture of glycopeptides. In particular, by introducing hydrophilic monomers via a bottom-up approach, the 2-D COF (denoted as NENP-1) nanosheets were provided with abundant amino groups and inherent hydrophilicity. Owing to the specific surface area and excessive accessible sites for hydrophilicity, the resulting NENP-1 nanosheets exhibited an outstanding glycopeptide enrichment efficiency from standard samples with a superior detection sensitivity (1 × 10-10 M), good enrichment selectivity (1 : 800, HRP tryptic digest to BSA protein), excellent binding capacity (100 mg g-1), great reusability, and recovery (60.2%). Furthermore, using the NENP-1 nanosheet adsorbent, twenty-four endogenous glycopeptides in the serum of patients with gastric cancer were successfully identified by LC-MS/MS technology, which illustrates a promising prospective of hydrophilic COF nanosheets in glycoproteomics research.

Recent advances of multifunctional zwitterionic polymers for biomedical application

Zwitterionic polymers possess equal total positive and negative charges in the repeating units, making them electrically neutral overall. This unique property results in superhydrophilicity, which makes the zwitterionic polymers highly effective in resisting protein adsorption, thus endowing the drug carriers with long blood circulation time, inhibiting thrombus formation on biomedical devices in contact with blood, and ensuring the good sensitivity of sensors in biomedical application. Moreover, zwitterionic polymers have tumor-targeting ability and pH-responsiveness, rendering them ideal candidates for antitumor drug delivery. Additionally, the high ionic conductivity of zwitterionic polymers makes them an important raw material for ionic skin. Zwitterionic polymers exhibit remarkable resistance to bacterial adsorption and growth, proving their suitability in a wide range of biomedical applications such as ophthalmic applications, and wound dressings. In this paper, we provide an in-depth analysis of the different structures and characteristics of zwitterionic polymers and highlight their unique qualities and suitability for biomedical applications. Furthermore, we discuss the limitations and challenges that must be overcome to realize the full potential of zwitterionic polymers and present an optimistic perspective for zwitterionic polymers in the biomedical fields. STATEMENT OF SIGNIFICANCE: Zwitterionic polymers have a series of excellent properties such as super hydrophilicity, anti-protein adsorption, antibacterial ability and good ionic conductivity. However, biomedical applications of multifunctional zwitterionic polymers are still a major field to be explored. This review focuses on the design and application of zwitterionic polymers-based nanosystems for targeted and responsive delivery of antitumor drugs and cancer diagnostic agents. Moreover, the use of zwitterionic polymers in various biomedical applications such as biomedical devices in contact with blood, biosensors, ionic skin, ophthalmic applications and wound dressings is comprehensively described. We discuss current results and future challenges for a better understanding of multifunctional zwitterionic polymers for biomedical applications.

Dual-ligand hydrogen-bonded organic framework: Tailored for mono-phosphopeptides and glycopeptides analysis

Hydrogen-bonded organic frameworks (HOFs) have emerged as a promising class of materials for applications of separation and enrichment. Utilizing multiple-ligands to construct HOFs is a promising avenue towards the development of structurally stable and functionally diverse frameworks, offering opportunities to create customized binding sites for selective recognition of biomolecules. In recent years, due to the crucial role that protein post-translational modifications (PTMs) play in maintaining protein function and regulating signaling pathways, and the growing recognition of the extensive cross-talk that can occur between PTMs, simultaneous analysis of different types of PTMs represents a requirement of a new generation of enrichment materials. Here, for the first attempt, we report a dual-ligand HOF constructed from borate anion and guanidinium cation for the simultaneous identification of glycopeptides and phosphopeptides, especially mono-phosphopeptides. According to theoretical calculations, the HOF functional sites display a synergistic "matching" effect with mono-phosphopeptides, resulting in a stronger enrichment effect for mono-phosphopeptides as compared to multi-phosphopeptides. Also, due to its high hydrophilicity and boronate affinity, this material can efficiently capture glycoproteins. HOF is set to become an active research direction in the development of highly efficient simultaneous protein enrichment materials, and offers a new approach for comprehensive PTMs analysis.

A new soft tissue constructed with chitosan for wound dressings-incorporating nanoparticles for medical and nursing therapeutic efficacy

The skin, being the largest organ in the human body, plays a vital role in shielding internal organs from external physical and chemical factors. However, skin damage caused by various factors such as injuries, surgeries, diabetes, or burns can lead to wounds that diminish the skin's protective function. Monitoring essential physiological parameters like temperature, moisture, and pH is crucial to facilitate antibiotic treatment, remote physician monitoring, patient comfort, cost reduction, and prevention of hospital-acquired infections. To this end, innovative wound coverings made of biological materials like gelatin, carboxymethyl chitosan, and titanium nanoparticles have been developed, mainly for hospital and pediatric applications. These wound coverings come equipped with sensors to monitor temperature, pH, and moisture and are suitable for pediatric hospitals where children experience difficulty in wound healing due to their sensitive skin. The temperature monitoring feature allows physicians to accurately assess the wound's temperature, detect potential infections, and take prompt actions. These wound coverings can significantly enhance wound treatment for patients, as real-time monitoring of physiological parameters enables informed decision-making by physicians, leading to better therapeutic outcomes. Furthermore, the use of these wound coverings can minimize the risk of hospital-acquired infections. Their adaptability and flexibility make them ideal for various wound types and sizes, ensuring patient comfort and compliance with the treatment plan. In conclusion, the development of innovative and flexible wound coverings using biological materials and equipped with sensors represents a significant breakthrough in wound management. The use of these wound coverings has the potential to revolutionize wound care and improve patient outcomes, particularly in pediatric hospitals where wound healing is often challenging.

In situ grown magnetic COF@MOF with a phosphoserine anchor for in-depth N-glycopeptide analysis in serum

A hydrophilic phosphoserine-functionalized magnetic organic framework composite (termed Fe3O4@COF@MOF-PS) was synthesized by an in situ growth strategy for effective capture of N-glycopeptides. Fe3O4@COF@MOF-PS exhibited high sensitivity (0.2 fmol μL-1), outstanding exclusion of size capability (1 : 10 000), good selectivity (1 : 2000), and reusability (at least 10 times). It also exhibited remarkable performance in the N-glycopeptide analysis in complex biological samples. Via nano-LC-MS/MS analysis, a total of 223 N-glycopeptides with 161 glycosylation sites assigned to 91 glycoproteins and 331 N-glycopeptides with 243 glycosylation sites assigned to 134 glycoproteins were identified in sera from cervical cancer patients and normal controls, respectively. Biological processes and molecular functional analyses indicate that the captured glycoproteins are of significant relevance to cervical cancer, for example, gene coverage or expression of cell adhesion and extracellular matrix structural constituents. Thus, Fe3O4@COF@MOF-PS not only efficiently captures N-glycopeptides, but also has the possibility of screening potential disease markers and elucidating the process of cervical cancer development.

Cerium ions immobilized magnetic graphite nitride decorated with L-Alanyl-L-Glutamine as new chelator for enrichment of phosphopeptides

Cerium ions immobilized magnetic graphite nitride material have been prepared using L-Alanyl-L-Glutamine as the new chelator. The resulting Fe3O4/g-C3N4-L-Ala-L-Gln-Ce4+, as an immobilized metal ion affinity chromatography (IMAC) sorbent, was reusable. This is due to the strong coordination interaction between L-Alanyl-L-Glutamine and cerium ions. After a series of characterizations, the magnetic nanocomposite showed high surface area, good hydrophilicity, positive electricity, and magnetic response. Fe3O4/g-C3N4-L-Ala-L-Gln-Ce4+ had high sensitivity (0.1 fmol), selectivity (α-/β-casein/bovine serum albumin, 1:1:5000), and good recyclability (10 cycles). A total of 647 unique phosphopeptides mapped to 491 phosphoproteins were identified from A549 cell lysate by nano LC-MS analysis.

Effective Enrichment of Phosphopeptides Using Magnetic Polyoxometalate-Based Metal-Organic Frameworks

In this study, magnetic polyoxometalate-based metal-organic frameworks (Fe3O4-POMOFs) were designed and applied to the enrichment of phosphopeptides. Thanks to the abundant metal oxide and metal ion sites, the material had a strong affinity for phosphopeptides. Simultaneously, the high amount of amino and guanidyl groups provided hydrophilicity and positive charge for phosphopeptide capture. By coupling with MS detection, the established platform possessed good reusability, high sensitivity (0.01 fmol), and high selectivity (α-casein/β-casein/bovine serum albumin = 1:1:5000). Furthermore, the method was successfully used for the detection of phosphopeptides in nonfat milk, human serum, saliva, and A549 cell lysate, showing great potential for practical application.