Recyclable heparin and chitosan conjugated magnetic nanocomposites for selective removal of low-density lipoprotein from plasma

Dual stimulus-responsive renewable nanoadsorbent for selective adsorption of low-density lipoprotein in serum

Selective removal of ultra-high low-density lipoprotein (LDL) from the blood of hyperlipemia patients using hemoperfusion is considered an efficient method to prevent the deterioration of atherosclerotic cardiovascular disease. Based on the exceptional structure-function properties of multistimulus-responsive materials, we developed a magnetic photorenewable nanoadsorbent (Fe3O4@SiO2@Azo-COOH) with outstanding selectivity and regenerative characteristics, featuring functionalized azobenzene as the ligand. The dual-stimulus response endowed Fe3O4@SiO2@Azo-COOH with rapid separation and photoregenerative properties. The adsorbent demonstrated excellent removal efficiency of LDL with an adsorption capacity of 15.06 mg/g, and highly repetitive adsorption performance (≥5 cycles) under irradiation. Fe3O4@SiO2@Azo-COOH also exhibited remarkable adsorption properties and selectivity in human serum, with adsorption capacities of 10.93, 21.26 and 9.80 mg/g for LDL, total cholesterol and triglycerides and only 0.77 mg/g for high-density lipoprotein (HDL), resulting in a 93% selective adsorption difference (LDL/HDL). Complete green regeneration of the nanoadsorbent was achieved through a simple regeneration process, maintaining a recovery rate of 99.4% after five regeneration experiments. By combining dynamic perfusion experiment with micromagnetic microfluidics, the LDL content decreased by 16.6%. Due to its superior adsorption capacity and regenerative properties, the dual stimulus-responsive nanosorbent is considered a potential hemoperfusion adsorbent.

Functionalized Periodic Mesoporous Silica Nanoparticles for Inhibiting the Progression of Atherosclerosis by Targeting Low-Density Lipoprotein Cholesterol

Atherosclerotic disease is a substantial global burden, and existing treatments, such as statins, are recommended to lower low-density lipoprotein cholesterol (LDL-C) levels and inhibit the progression of atherosclerosis. However, side effects, including gastrointestinal unease, potential harm to the liver, and discomfort in the muscles, might be observed. In this study, we propose a novel method using periodic mesoporous silica nanoparticles (PMS) to create heparin-modified PMS (PMS-HP) with excellent biocompatibility, enabling selective removal of LDL-C from the blood. In vitro, through the introduction of PMS-HP into the plasma of mice, we observed that, compared to PMS alone, PMS-HP could selectively adsorb LDL-C while avoiding interference with valuable components such as plasma proteins and high-density lipoprotein cholesterol (HDL-C). Notably, further investigations revealed that the adsorption of LDL-C by PMS-HP could be well-fitted to quasi-first-order (R2 = 0.993) and quasi-second-order adsorption models (R2 = 0.998). Likewise, in vivo, intravenous injection of PMS-HP enabled targeted LDL-C adsorption (6.5 ± 0.73 vs. 8.6 ± 0.76 mM, p < 0.001) without affecting other plasma constituents, contributing to reducing intravascular plaque formation (3.66% ± 1.06% vs. 1.87% ± 0.79%, p < 0.05) on the aortic wall and inhibiting vascular remodeling (27.2% ± 6.55% vs. 38.3% ± 1.99%, p < 0.05). Compared to existing lipid adsorption techniques, PMS-HP exhibited superior biocompatibility and recyclability, rendering it valuable for both in vivo and in vitro applications.

A review: hemocompatibility of magnetic nanoparticles and their regenerative medicine, cancer therapy, drug delivery, and bioimaging applications

Nanoparticles have demonstrated noteworthy advancements in the management of various complex medical conditions, particularly cancer. In any case, these particles still harbor the potential to improve medicate conveyance to challenging, hard-to-reach loci. The interactions that occur between nanoparticles and red blood cells during their journey throughout the human body, despite exposure to blood, are still not fully understood. Assessment of the ability of nanoparticles to integrate with blood, characterized as nanoparticle compatibility, has been consistently overlooked and undervalued in its import. This review article investigates the effect of nanoparticles on red blood cells, while examining the compatibility of nanoparticles through the angle of hemolysis. This article discusses the main roles of erythrocytes and also provides an informed interpretation of several mechanisms involved in the interaction of nanoparticles and erythrocytes. Throughout the review, significant emphasis is attributed to the investigation of hemocompatibility studies concerning newly designed nanoparticles to promote their successful translation into clinical application. This review article examines the compatibility of magnetic nanoparticles in various fields, including regenerative medicine, cancer therapy, bioimaging, and drug delivery. Our results show that the chemical composition of the nanoparticle surface is a determining factor in hemocompatibility performance and interaction with blood cells. The surface properties of nanoparticles, namely surface charge, geometry, porosity, and surface functionalities of polymers or specific functional groups, represent key determinants of hemocompatibility.

The Emerging Role of the Gut Microbiome in Cardiovascular Disease: Current Knowledge and Perspectives

The collection of normally non-pathogenic microorganisms that mainly inhabit our gut lumen shapes our health in many ways. Structural and functional perturbations in the gut microbial pool, known as “dysbiosis”, have been proven to play a vital role in the pathophysiology of several diseases, including cardiovascular disease (CVD). Although therapeutic regimes are available to treat this group of diseases, they have long been the main cause of mortality and morbidity worldwide. While age, sex, genetics, diet, tobacco use, and alcohol consumption are major contributors (World Health Organization, 2018), they cannot explain all of the consequences of CVD. In addition to the abovementioned traditional risk factors, the constant search for novel preventative and curative tools has shed light on the involvement of gut bacteria and their metabolites in the pathogenesis of CVD. In this narrative review, we will discuss the established interconnections between the gut microbiota and CVD, as well as the plausible therapeutic perspectives.

Gut microbiota and cardiovascular disease: opportunities and challenges

Coronary artery disease (CAD) is the most common health problem worldwide and remains the leading cause of morbidity and mortality. Over the past decade, it has become clear that the inhabitants of our gut, the gut microbiota, play a vital role in human metabolism, immunity, and reactions to diseases, including CAD. Although correlations have been shown between CAD and the gut microbiota, demonstration of potential causal relationships is much more complex and challenging. In this review, we will discuss the potential direct and indirect causal roots between gut microbiota and CAD development via microbial metabolites and interaction with the immune system. Uncovering the causal relationship of gut microbiota and CAD development can lead to novel microbiome-based preventative and therapeutic interventions. However, an interdisciplinary approach is required to shed light on gut bacterial-mediated mechanisms (e.g., using advanced nanomedicine technologies and incorporation of demographic factors such as age, sex, and ethnicity) to enable efficacious and high-precision preventative and therapeutic strategies for CAD.

Magnetic cucurbit[6]uril-based hypercrosslinked polymers for efficient enrichment of ubiquitin

The design and preparation of magnetic cucurbit[6]uril hypercrosslinked with polymers are described. The materials have a large specific surface, abundant mesopores and cavities, and display superparamagnetism. They were applied to the enrichment of ubiquitinated peptides from standard protein digests. Following desorption with 0.15% TFA, the peptides were quantified by MALDI-TOF MS. The method has a detection limit of 2 fmol·μL^-1 and a mass ratio selectivity of 1:5000 as shown for ubiquitin and bovine serum albumin. The materials enable selective capture of ubiquitinated peptides from genuine samples comprising of oyster mushroom and human serum. This demonstrates their potential for the analysis of low-level ubiquitin in complex samples. Graphical abstract Schematic presentation for the synthesis of magnetic cucurbit[6]urils hypercrosslinked polymers (MagCB[6]-HCPs).

Selective Electrochemical Capture and Release of Heparin Based on Amine-Functionalized Carbon/Titanium Dioxide Nanotube Arrays

Heparin (HEP) is a sulfated glycosaminoglycan that is a clinical anticoagulant agent. Commercially derived from porcine intestinal mucosa, HEP is challenging to separate from this complex biological mixture for additional purification. This study aimed to raise the purity of isolated HEP using electrochemical potential to increase its selective capture and release. We demonstrate an electrochemical platform featuring an anode composed of amine-functionalized carbon/titanium dioxide nanotube arrays on titanium foil (Ti/C-TNTAs-NH₂) and a cathode made of expanded graphite. Our results show that Ti and Ti/C-TNTAs control plates do not adsorb HEP, even while applying an external potential to the cell. However, when the Ti/C-TNTAs electrode is modified by 3 aminopropyltriethoxysilane, the terminal NH₂ groups provide a high density of positive charges that serve as binding sites, enabling the adsorption of HEP. This attraction is further strengthened by applying an external potential to the anode. Subsequent release of the HEP molecules and regeneration of the Ti/C-TNTAs-NH₂ electrode are easily accomplished by applying an anodic potential to the plate, as well as by increasing the concentration of NaCl in solution. This electrochemical system demonstrates the good selectivity of HEP, even within a mixture of other probable interfering species (e.g., bovine serum albumin and chondroitin sulfate). Additionally, it maintains 90.11% of its initial electrosorption efficiency after ten repeated HEP adsorption/desorption cycles, indicating this system's promising stability and reusability for HEP purification.

A mussel-inspired approach towards heparin-immobilized cellulose gel beads for selective removal of low density lipoprotein from whole blood

In this study, we report a mussel-inspired approach to fabricate heparin-immobilized cellulose (HeTaCe) gel beads with self-anticoagulative and biocompatible properties which can selectively remove low density lipoprotein (LDL) from whole blood directly. First, a phase inversion technique was applied to prepare cellulose gel beads. Then the as-prepared gel beads were dipped into a mixed solution of heparin and tannic acid in phosphate buffered saline (PBS, pH 8.5) to obtain HeTaCe gel beads. Blood compatibility experiments indicated that the HeTaCe gel beads could suppress complement activation as well as contact activation and prolong the clotting times to the upper detect limits (activated partial thromboplastin time >600 s and thrombin time >180 s) of the automated blood coagulation analyzer. An ideal adsorption capacity of LDL in vitro was achieved by the HeTaCe gel beads with an amount of 79.1 mg/g. Besides, dynamic column adsorption test further demonstrated a selective adsorption of LDL without a significant reduction of high density lipoprotein (HDL) in a simulative hemoperfusion system. It is believed that the HeTaCe gel beads will be quite appealing to future clinical practice aiming at lowering LDL and improving the outcomes of patients with high cardiovascular risk.

Naturally derived proteins and glycosaminoglycan scaffolds for tissue engineering applications

Tissue engineering (TE) aims to mimic the complex environment where organogenesis takes place using advanced materials to recapitulate the tissue niche. Cells, three-dimensional scaffolds and signaling factors are the three main and essential components of TE. Over the years, materials and processes have become more and more sophisticated, allowing researchers to precisely tailor the final chemical, mechanical, structural and biological features of the designed scaffolds. In this review, we will pose the attention on two specific classes of naturally derived polymers: fibrous proteins and glycosaminoglycans (GAGs). These materials hold great promise for advances in the field of regenerative medicine as i) they generally undergo a fast remodeling in vivo favoring neovascularization and functional cells organization and ii) they elicit a negligible immune reaction preventing severe inflammatory response, both representing critical requirements for a successful integration of engineered scaffolds with the host tissue. We will discuss the recent achievements attained in the field of regenerative medicine by using proteins and GAGs, their merits and disadvantages and the ongoing challenges to move the current concepts to practical clinical application.

Synthesis of tumor-targeted folate conjugated fluorescent magnetic albumin nanoparticles for enhanced intracellular dual-modal imaging into human brain tumor cells

Superparamagnetic iron oxide nanoparticles (SPIO NPs), utilized as carriers are attractive materials widely applied in biomedical fields, but target-specific SPIO NPs with lower toxicity and excellent biocompatibility are still lacking for intracellular visualization in human brain tumor diagnosis and therapy. Herein, bovine serum albumin (BSA) coated superparamagnetic iron oxide, i.e. γ-Fe2O3 nanoparticles (BSA-SPIO NPs), are synthesized. Tumor-specific ligand folic acid (FA) is then conjugated onto BSA-SPIO NPs to fabricate tumor-targeted NPs, FA-BSA-SPIO NPs as a contrast agent for MRI imaging. The FA-BSA-SPIO NPs are also labeled with fluorescein isothiocyanate (FITC) for intracellular visualization after cellular uptake and internalization by glioma U251 cells. The biological effects of the FA-BSA-SPIO NPs are investigated in human brain tumor U251 cells in detail. These results show that the prepared FA-BSA-SPIO NPs display undetectable cytotoxicity, excellent biocompatibility, and potent cellular uptake. Moreover, the study shows that the made FA-BSA-SPIO NPs are effectively internalized for MRI imaging and intracellular visualization after FITC labeling in the targeted U251 cells. Therefore, the present study demonstrates that the fabricated FITC-FA-BSA-SPIO NPs hold promising perspectives by providing a dual-modal imaging as non-toxic and target-specific vehicles in human brain tumor treatment in future.

Polysaccharide-based nanocomposites and their applications

Polysaccharide nanocomposites have become increasingly important materials over the past decade. Polysaccharides offer a green alternative to synthetic polymers in the preparation of soft nanomaterials. They have also been used in composites with hard nanomaterials, such as metal nanoparticles and carbon-based nanomaterials. This mini review describes methods for polysaccharide nanocomposite preparation and reviews the various types and diverse applications for these novel materials.

Impact of hydrophobic chain composition on amphiphilic macromolecule antiatherogenic bioactivity

Amphiphilic macromolecules (AMs) composed of sugar backbones modified with branched aliphatic chains and a poly(ethylene glycol) (PEG) tail can inhibit macrophage uptake of oxidized low-density lipoproteins (oxLDL), a major event underlying atherosclerosis development. Previous studies indicate that AM hydrophobic domains influence this bioactivity through interacting with macrophage scavenger receptors, which can contain basic and/or hydrophobic residues within their binding pockets. In this study, we compare two classes of AMs to investigate their ability to promote athero-protective potency via hydrogen-bonding or hydrophobic interactions with scavenger receptors. A series of ether-AMs, containing methoxy-terminated aliphatic arms capable of hydrogen-bonding, was synthesized. Compared to analogous AMs containing no ether moieties (alkyl-AMs), ether-AMs showed improved cytotoxicity profiles. Increasing AM hydrophobicity via incorporation of longer and/or alkyl-terminated hydrophobic chains yielded macromolecules with enhanced oxLDL uptake inhibition. These findings indicate that hydrophobic interactions and the length of AM aliphatic arms more significantly influence AM bioactivity than hydrogen-bonding.