Model protein BSA adsorption onto novel magnetic chitosan/PVA/laponite RD hydrogel nanocomposite beads

Nanocomposite Hydrogel for Real-Time Wound Status Monitoring and Comprehensive Treatment

Current skin sensors or wound dressings fall short in addressing the complexities and challenges encountered in real-world scenarios, lacking adequate capability to facilitate wound repair. The advancement of methodologies enabling early diagnosis, real-time monitoring, and active regulation of drug delivery for timely comprehensive treatment holds paramount significance for complex chronic wounds. In this study, a nanocomposite hydrogel is devised for real-time monitoring of wound condition and comprehensive treatment. Tannins and siRNA containing matrix metalloproteinase-9 gene siRNA interference are self-assembled to construct a degradable nanogel and modified with bovine serum albumin. The nanogel and pH indicator are encapsulated within a dual-crosslinking hydrogel synthesized with norbornene dianhydride-modified paramylon. The hydrogel exhibited excellent shape adaptability due to borate bonding, and the click polymerization reaction led to rapid in situ curing of the hydrogel. The system not only monitors pH, temperature, wound exudate alterations, and peristalsis during wound healing but also exhibits hemostatic, antimicrobial, anti-inflammatory, and antioxidant properties, modulates macrophage polarization, and facilitates vascular tissue regeneration. This therapeutic approach, which integrates the monitoring of pathological parameters with comprehensive treatment, is anticipated to address the clinical issues and challenges associated with chronic diabetic wounds and infected wounds, offering broad prospects for application.

Trends in sustainable chitosan-based hydrogel technology for circular biomedical engineering: A review

Eco-friendly materials have emerged in biomedical engineering, driving major advances in chitosan-based hydrogels. These hydrogels offer a promising green alternative to conventional polymers due to their non-toxicity, biodegradability, biocompatibility, environmental friendliness, affordability, and easy accessibility. Known for their remarkable properties such as drug encapsulation, delivery capabilities, biosensing, functional scaffolding, and antimicrobial behavior, chitosan hydrogels are at the forefront of biomedical research. This paper explores the fabrication and modification methods of chitosan hydrogels for diverse applications, highlighting their role in advancing climate-neutral healthcare technologies. It reviews significant scientific advancements and trends chitosan hydrogels focusing on cancer diagnosis, drug delivery, and wound care. Additionally, it addresses current challenges and green synthesis practices that support a circular economy, enhancing biomedical sustainability. By providing an in-depth analysis of the latest evidence on climate-neutral management, this review aims to facilitate informed decision-making and foster the development of sustainable strategies leveraging chitosan hydrogel technology. The insights from this comprehensive examination are pivotal for steering future research and applications in sustainable biomedical solutions.

Polycarboxylate functionalized magnetic nanoparticles Fe3O4@SiO2@CS-COOH: Preparation, characterization, and immobilization of bovine serum albumin

Magnetic nanoparticles with increasing superparamagnetism and magnetic targeting have found widespread application in fields such as food and medicine. In this study, polycarboxylated magnetic nanoparticles (Fe3O4@SiO2@CS-COOH) were prepared by surface functionalizing iron tetraoxide (Fe3O4) nanoparticles with ethylenediaminetetraacetic acid (EDTA) as a modifier. The appropriate degree of functionalization modification was obtained by adjusting the EDTA concentration and the ratio of cross-linking agents. The prepared magnetic nanoparticles were analyzed with structural and property characterization. The results showed that the Fe3O4@SiO2@CS-COOH magnetic nanoparticles prepared with 4 % EDTA and cross-linking agents at a molar ratio of 3:4 were uniform in particle size, with an average size of roughly 7 nm, and possessed an abundant carboxylate content (310.8064 μmol/g) and a high magnetization intensity (35.05 emu/g). As a model protein, bovine serum albumin (BSA) was immobilized on the surface of magnetic particles. The largest amount of immobilized protein was 500.4376 mg BSA/g at pH 4.0 and no extra salt ions. According to molecular docking simulations, its immobilization was due to the interaction of amino and carboxyl groups at the Fe3O4@SiO2@CS-COOH/BSA interface. Fe3O4@SiO2@CS-COOH possesses a large number of carboxyl groups, strong protein immobilization, and magnetic responsiveness, which may have potential applications in biomedical and food fields.

Sustainable aerogels based on biobased poly (itaconic acid) for adsorption of cationic dyes

This work reports the synthesis of poly (itaconic acid) by thermal polymerization mediated by 2,2'-Azobis(2-methylpropionamidine) dihydrochloride. Furthermore, physical hydrogels were prepared by using high molecular weight poly (itaconic acid) characterized by low dispersity and laponite RD. The hydrogels presented porous 3D network structures, with a high-water penetration of almost 2000 g/g of swelling ratio, which can allow the adsorption sites of both poly (itaconic acid) and laponite RD to be easily exposed and facilitate the adsorption of dyes. The water adsorption followed Schott's pseudo-second-order model. The mechanism of the adsorption process was investigated using 1H and 31P NMR. The hydrogel is able to fast adsorb by a combination of electrostatic interactions and hydrogen bonding by the synergic effect of the clay and poly (itaconic acid). Moreover, the prepared aerogels exhibited a fast removal of Basic Fuchsin, with an adsorption capacity of 67.56 mg/g and a high removal efficiency (~99 %). The adsorption followed the pseudo-second-order kinetic model and Langmuir isotherm model. Furthermore, the thermodynamic parameters showed that the BF process of adsorption was spontaneous and feasible, endothermic, and followed physisorption. These results indicated that the PIA/laponite-based aerogel can be considered a promising adsorbent material in textile wastewater treatment.

Protein corona, influence on drug delivery system and its improvement strategy: A review

Nano drug delivery systems offer several benefits, including enhancing drug solubility, regulating drug release, prolonging drug circulation time, and minimized toxicity and side effects. However, upon entering the bloodstream, nanoparticles (NPs) encounter a complex biological environment and get absorbed by various biological components, primarily proteins, leading to the formation of a 'Protein Corona'. The formation of the protein corona is affected by the characteristics of NPs, the physiological environment, and experimental design, which in turn affects of the immunotoxicity, specific recognition, cell uptake, and drug release of NPs. To improve the abundance of a specific protein on NPs, researchers have explored pre-coating, modifying, or wrapping NPs with the cell membrane to reduce protein adsorption. This paper, we have reviewed studies of the protein corona in recent years, summarized the formation and detection methods of the protein corona, the effect of the protein corona composition on the fate of NPs, and the design of new drug delivery systems based on the optimization of protein corona to provide a reference for further study of the protein corona and a theoretical basis for the clinical transformation of NPs.

Modulation of Methacrylated Hyaluronic Acid Hydrogels Enables Their Use as 3D Cultured Model

Bioengineered hydrogels represent physiologically relevant platforms for cell behaviour studies in the tissue engineering and regenerative medicine fields, as well as in in vitro disease models. Hyaluronic acid (HA) is an ideal platform since it is a natural biocompatible polymer that is widely used to study cellular crosstalk, cell adhesion and cell proliferation, and is one of the major components of the extracellular matrix (ECM). We synthesised chemically modified HA with photo-crosslinkable methacrylated groups (HA-MA) in aqueous solutions and in strictly monitored pH and temperature conditions to obtain hydrogels with controlled bulk properties. The physical and chemical properties of the different HA-MA hydrogels were investigated via rheological studies, mechanical testing and scanning electron microscopy (SEM) imaging, which allowed us to determine the optimal biomechanical properties and develop a biocompatible scaffold. The morphological evolution processes and proliferation rates of glioblastoma cells (U251-MG) cultured on HA-MA surfaces were evaluated by comparing 2D structures with 3D structures, showing that the change in dimensionality impacted cell functions and interactions. The cell viability assays and evaluation of mitochondrial metabolism showed that the hydrogels did not interfere with cell survival. In addition, morphological studies provided evidence of cell-matrix interactions that promoted cell budding from the spheroids and the invasiveness in the surrounding environment.

Recent advances of magnetic chitosan hydrogel: Preparation, properties and applications

Magnetic chitosan hydrogels are organic-inorganic composite material with the characteristics of both magnetic materials and natural polysaccharides. Due to its biocompatibility, low toxicity and biodegradability, chitosan, a natural polymer has been widely used for preparing magnetic hydrogels. The addition of magnetic nanoparticles to chitosan hydrogels not only improves their mechanical strength, but also endows them with magnetic thermal effects, targeting capabilities, magnetically-sensitive release characteristics, easy separation and recovery, thus enabling them to be used in various applications including drug delivery, magnetic resonance imaging, magnetothermal therapy, and adsorption of heavy metals and dyes. In this review, the physical and chemical crosslinking methods of chitosan hydrogels and the methods for binding magnetic nanoparticles in hydrogel networks are first introduced. Subsequently, the properties of magnetic chitosan hydrogels were summarized including mechanical properties, self-healing, pH responsiveness and properties in magnetic fields. Finally, the potential for further technological and applicative advancements of magnetic chitosan hydrogels is discussed.

Removal of anionic and cationic dyes using porous chitosan/carboxymethyl cellulose-PEG hydrogels: Optimization, adsorption kinetics, isotherm and thermodynamics studies

Chitosan (CS)/carboxymethyl cellulose (CMC) porous hydrogels chemically crosslinked by epichlorohydrin were synthesized using polyethylene glycol (PEG) as a pore-forming agent for anionic (Congo red, CR) and cationic (methylene blue, MB) dyes removal from aqueous solutions. The swelling ratio of hydrogels prepared with 2 % CS and 2 % CMC (CS₂/CMC₂) exhibited optimal performance at different pHs. The addition of PEG into hydrogels (denoted as CS₂/CMC₂-PEG_1.25) exhibited a significantly higher adsorption for CR and MB, increasing from 117.83 to 159.12 mg/g and 110.2 to 136 mg/g, respectively. The comprehensive analyses of Fourier transform infrared spectroscopy, thermalgravimetric study and scanning electron microscopy showed that CS₂/CMC₂-PEG_1.25 hydrogels became more porous with no significant changes in intermolecular and intramolecular interactions, compared with CS₂/CMC₂ hydrogels. The adsorption process for CR and MB conformed to the pseudo-second-order and pseudo-first-order kinetics models, respectively. The results of adsorption isotherm for CR followed both Freundlich and Langmuir models with the maximum adsorption capacities of 1053.88 mg/g, whereas the isotherm for MB fitted the Langmuir model better with the maximum adsorption capacities of 331.72 mg/g. The thermodynamic study results proved that the CR and MB adsorption by hydrogels was spontaneous, but the CR adsorption was endothermic and the MB adsorption was exothermic.

Preparation and Characterization of Protein Molecularly Imprinted Poly (Ionic Liquid)/Calcium Alginate Composite Cryogel Membrane with High Mechanical Strength for the Separation of Bovine Serum Albumin

In order to improve the mechanical strength and imprinting efficiency, a novel bovine serum albumin (BSA) molecularly imprinted poly(ionic liquid)/calcium alginate composite cryogel membrane (MICM) was prepared. The results of the tensile test indicated that the MICM had excellent mechanical strength which could reach up to 90.00 KPa, 30.30 times higher than the poly (ionic liquid) membrane without calcium alginate; the elongation of it could reach up to 93.70%, 8.28 times higher than the poly (ionic liquid) membrane without calcium alginate. The MICM had a very high welling ratio of 1026.56% and macropore porosity of 62.29%, which can provide effective mass transport of proteins. More remarkably, it had a very high adsorption capacity of 485.87 mg g-1 at 20 °C and 0.66 mg mL-1 of the initial concentration of BSA. Moreover, MICM also had good selective and competitive recognition toward BSA, exhibiting potential utility in protein separation. This work can provide a potential method to prepare the protein-imprinted cryogel membrane with both high mechanical strength and imprinting efficiency.

Multifunctional dual cross-linked poly (vinyl alcohol)/methacrylate hyaluronic acid/chitooligosaccharide-sinapic acid wound dressing hydrogel

Wound dressing hydrogel with multifunctional properties, including antioxidant and antimicrobial properties and appropriate mechanical, biological, and physical properties is of great interest in wound healing application and it is still a challenge. In the present study, chitooligosaccharides (COS)/ sinapic acid (SA) conjugate (COS-SA) was synthesized using H₂O₂-induced grafting polymerization, and photo cross-linkable hyaluronic acid was synthesized using methacrilation (HAMA). The synthesis of COS-SA and HAMA was confirmed by Fourier-transform infrared spectroscopy, proton nuclear magnetic resonance spectroscopy, ultraviolet spectroscopy, and polyphenol assay. Subsequently, we developed duel cross-linked polyvinyl alcohol (PVA)/HAMA composite hydrogel encapsulated with COS-SA as an antioxidant and antimicrobial dressing for full-thickness wound healing application. The chemical, physical, mechanical, antioxidant, antimicrobial, in vitro biocompatibility, and in vivo wound healing properties of hydrogels were subsequently investigated. The results showed that the fabricated composite hydrogel had a uniform porous architecture, excellent fluid absorbability, and appropriate mechanical stability. The introduction of COSs-SA conjugate remarkably enhanced the in vitro biocompatibility, antioxidant, and antimicrobial properties of the hydrogel, leading to the significant promotion of in vivo full-thickness wound closure, re-epithelization, granulation tissue formation, and collagen deposition indicating that COSs-SA incorporated PVA/HAMA hydrogel wound dressing has significant potential for chronic wound healing application.

LAPONITE® nanodisk-"decorated" Fe3O4 nanoparticles: a biocompatible nano-hybrid with ultrafast magnetic hyperthermia and MRI contrast agent ability

Magnetic Fe₃O₄ nanoparticles "decorated" by LAPONITE® nanodisks have been materialized utilizing the Schikorr reaction following a facile approach and tested as mediators of heat for localized magnetic hyperthermia (MH) and as magnetic resonance imaging (MRI) agents. The synthetic protocol involves the interaction between two layered inorganic compounds, ferrous hydroxide, Fe(OH)₂, and the synthetic smectite LAPONITE® clay Na_0.7⁺[(Si₈Mg_5.5Li_0.3)O₂₀(OH)₄]_0.7^-, towards the formation of superparamagnetic Fe₃O₄ nanoparticles, which are well decorated by the diamagnetic clay nanodisks. The latter imparts high negative ζ-potential values (up to -34.1 mV) to the particles, which provide stability against flocculation and precipitation, resulting in stable water dispersions. The obtained LAPONITE®-"decorated" Fe₃O₄ nanohybrids were characterized by powder X-ray diffraction (XRD), transmission electron microscopy (TEM), Mössbauer spectroscopy, dynamic light scattering (DLS) and vibrating sample magnetometry (VSM) at room temperature, revealing superior magnetic hyperthermia performance with specific absorption rate (SAR) values reaching 540 W g_Fe^-1 (28 kA m^-1, 150 kHz) for the hybrid material with a magnetic loading of 50 wt% Fe₃O₄/LAPONITE®. Toxicity studies were also performed with human glioblastoma (GBM) cells and human foreskin fibroblasts (HFF), which show negligible to no toxicity. Furthermore, T₂-weighted MR imaging of rodent brain shows that the LAPONITE®-"decorated" Fe₃O₄ nanohybrids predominantly affected the transverse T₂ relaxation time of tissue water, which resulted in a signal drop on the MRI T₂-weighted imaging, allowing for imaging of the magnetic nanoparticles.

Advances of Stimulus-Responsive Hydrogels for Bone Defects Repair in Tissue Engineering

Bone defects, as one of the most urgent problems in the orthopedic clinic, have attracted much attention from the biomedical community and society. Hydrogels have been widely used in the biomedical field for tissue engineering research because of their excellent hydrophilicity, biocompatibility, and degradability. Stimulus-responsive hydrogels, as a new type of smart biomaterial, have more advantages in sensing external physical (light, temperature, pressure, electric field, magnetic field, etc.), chemical (pH, redox reaction, ions, etc.), biochemical (glucose, enzymes, etc.) and other different stimuli. They can respond to stimuli such as the characteristics of the 3D shape and solid-liquid phase state, and exhibit special properties (injection ability, self-repair, shape memory, etc.), thus becoming an ideal material to provide cell adhesion, proliferation, and differentiation, and achieve precise bone defect repair. This review is focused on the classification, design concepts, and research progress of stimulus-responsive hydrogels based on different types of external environmental stimuli, aiming at introducing new ideas and methods for repairing complex bone defects.

Removal of Cr(VI) by biochar derived via co-pyrolysis of oily sludge and corn stalks

The co-pyrolysis of oily sludge with biomass to prepare carbon materials is not only an effective way to mitigate oily sludge pollution, but it is also a method of obtaining carbon materials. In this study, a carbon material (OS-CS AC) was obtained by the direct co-pyrolysis of oily sludge (OS) and corn stalks (CS) and then applied to Cr(VI) removal. According to the hydroxy and carboxy masking experiments and the characterization of OS-CS AC by FT-IR, SEM, XPS, XRD, and N₂ physical adsorption–desorption, Cr(VI) can be adsorbed efficiently through pore filling, the surface oxygen-containing functional groups can promote the reduction of Cr(VI) to Cr(III) through electron donors, and the greater the electrostatic attraction between the electron-donating functional groups of OS-CS AC and the Cr(VI) is, the stronger the ability to remove Cr(VI). In addition, the removal process was discussed, and the results indicated that the McKay kinetic model, Langmuir isotherm model and Van't Hoff thermodynamic model were the most suitable models for removal. The main factors affecting the removal of Cr(VI) were discussed, and the removal of Cr(VI) reached 99.14%, which gives a comprehensive utilization way of oily sludge and corn stalks.

Mono-Sized Anion-Exchange Magnetic Microspheres for Protein Adsorption

In this study, mono-sized anion-exchange microspheres with polyglycidylmethacrylate were engineered and processed to introduce magnetic granules by penetration-deposition approaches. The obtained magnetic microspheres showed a uniform particle diameter of 1.235 μm in average and a good spherical shape with a saturation magnetic intensity of 12.48 emu/g by VSM and 12% magnetite content by TGA. The magnetic microspheres showed no cytotoxicity when the concentration was below 10 μg/mg. The magnetic microspheres possess respective adsorption capacity for three proteins including Bovine albumin, Hemoglobin from bovine blood, and Cytochrome C. These magnetic microspheres are also potential biomaterials as targeting medicine carriers or protein separation carriers at low concentration.

Swelling, Protein Adsorption, and Biocompatibility In Vitro of Gel Beads Prepared from Pectin of Hogweed Heracleum sosnówskyi Manden in Comparison with Gel Beads from Apple Pectin

The study aims to develop gel beads with improved functional properties and biocompatibility from hogweed (HS) pectin. HS4 and AP4 gel beads were prepared from the HS pectin and apple pectin (AP) using gelling with calcium ions. HS4 and AP4 gel beads swelled in PBS in dependence on pH. The swelling degree of HS4 and AP4 gel beads was 191 and 136%, respectively, in PBS at pH 7.4. The hardness of HS4 and AP4 gel beads reduced 8.2 and 60 times, respectively, compared with the initial value after 24 h incubation. Both pectin gel beads swelled less in Hanks’ solution than in PBS and swelled less in Hanks’ solution containing peritoneal macrophages than in cell-free Hanks’ solution. Serum protein adsorption by HS4 and AP4 gel beads was 118 ± 44 and 196 ± 68 μg/cm² after 24 h of incubation. Both pectin gel beads demonstrated low rates of hemolysis and complement activation. However, HS4 gel beads inhibited the LPS-stimulated secretion of TNF-α and the expression of TLR4 and NF-κB by macrophages, whereas AP4 gel beads stimulated the inflammatory response of macrophages. HS4 gel beads adsorbed 1.3 times more LPS and adhered to 1.6 times more macrophages than AP4 gel beads. Thus, HS pectin gel has advantages over AP gel concerning swelling behavior, protein adsorption, and biocompatibility.

Hydroxyapatite grafted chitosan/laponite RD hydrogel: Evaluation of the encapsulation capacity, pH-responsivity, and controlled release behavior

In this study, a pH-responsive drug carrier was developed for the controllable release of drugs in the gastric environment. Chitosan (CS), a pH-sensitive biopolymer, and laponite RD (LAP), a nano-clay with a high drug-loading capability, were used to design the new carrier. Hydroxyapatite (HA) was grafted into CS/LAP matrix through a simple co-precipitation technique to overcome the burst release of the CS/LAP. The structural analysis and swelling tests of products demonstrated that the co-precipitation method has led to the penetration of HA nanoparticles inside the CS/LAP matrix and occupying its hollow pores. Occupation of the empty pores can lead to the entrapment of drug molecules, thereby reducing the release rate. The nanocomposite showed a high loading capacity to ofloxacin as a drug model. The effects of HA content on release behavior of nanocomposite were investigated at simulated gastric (pH 1.2) and intestine (pH 7.4) environments. The results indicated a high pH sensitivity for CS/LAP/HA. HA grafting reduced the release rate remarkably regardless of pH. The release rate of CS/LAP/HA decreased by 44-63% in pH 1.2 and 41-51% in pH 7.4 compared to CS/LAP. Kinetic studies indicated that grafting the HA in CS/LAP has changed the drug release mechanism.

Gamma radiation synthesis of a novel amphiphilic terpolymer hydrogel pH-responsive based chitosan for colon cancer drug delivery

Particularly, chitosan (Cs) loaded with drug cannot pass through the colonic region, often leading in the bursting drug release in the stomach due to its solubility in gastric contents. The novelty of the current article is to solve this limitation by performing gamma irradiation cross-linking of Cs with two anionic polymers of (acrylic acid)-co-(2-acrylamido-2-methylpropane-sulfonic acid) (AAc/AMPS) to give amphiphilic hydrogel. The shifted in the characteristic FTIR peaks of Cs in the (Cs/AAc/AMPS) confirm the exits of inter-molecular interactions that make Cs and (AAc/AMPS) are miscible. Swelling experiments under different pH indicated that the (Cs/AAc/AMPS) hydrogels were significantly sensitive to pH change. The results give the possibility to use the obtained (Cs/AAc/AMPS) hydrogel on drug delivery system. The in vitro Fluorouracil (5-FU) releasing from (Cs/AAc/AMPS) matrix was examined under the influence of pH1 and pH7.The results confirmed the hydrogels capability to release 96 % of 5-FU drug at pH 7 after 7 h.

Bisphenol A-induced Alterations in Different Stages of Spermatogenesis and Systemic Toxicity in Albino Mice (Mus musculus)

BACKGROUND

Bisphenol A (BPA) is known to alter sperm morphology, but information is limited on the most susceptible stage(s) of spermatogenesis, especially in mice.

OBJECTIVES

This study investigated the reproductive, biochemical, and hematological changes caused by exposure to BPA in male albino mice. The genotoxicity of BPA to the six stages of spermatogenesis in mice was determined.

METHODS

Mice were exposed orally to BPA at 0.5, 1.0, 2.0, and 5.0 mg/kg bw doses for 5 days and assessed for sperm morphology after 35 days. Based on the result, the second group of mice was exposed to BPA at 1.0 mg/kg bw dose for 5 days, their spermatozoa were assessed for sperm morphology based on BPA exposure at the 6 maturation stages of spermatogenesis: spermatozoa, elongating spermatids, round spermatids, secondary spermatocytes, primary spermatocytes, and spermatogonia. Biochemical and hematological analyses of the blood of exposed mice were also carried out.

RESULTS

The results showed that BPA induced concentration-dependent, significantly (p<0.05) increased sperm cell abnormalities at three of the four concentrations tested, with the exception of 0.5 mg/kg bw, in comparison with the negative control. The highest frequency of sperm aberrations was induced in spermatozoa exposed to BPA while at the primary spermatocytes. The order of induced sperm abnormality at the different stages of exposure was: primary spermatocytes > elongating spermatids > spermatozoa > spermatogonia > round spermatids > secondary spermatocytes. The results of the biochemical analysis showed significantly (p<0.05) increased serum urea, creatinine, and alanine aminotransferase (ALT) and aspartate aminotransferase (AST) activities with a concomitant decrease in total protein content at the various stages of spermatogenesis. In addition, the results for hematological parameters showed several significant (p<0.05) modulations in mice exposed to BPA.

CONCLUSIONS

These data showed that BPA is most toxic to primary spermatocytes and alterations of biochemical and hematological parameters might be the mechanisms of induced toxicity.

ETHICS APPROVAL

The Research Ethics Committee, Federal University of Technology, Akure approved the study protocols.

COMPETING INTERESTS

The authors declare no competing financial interests.

Protein corona, understanding the nanoparticle-protein interactions and future perspectives: A critical review

Proteins are biopolymers of highly varied structures taking part in almost all processes occurring in living cells. When nanoparticles (NPs) interact with proteins in biological environments, they are surrounded by a layer of biomolecules, mainly proteins adsorbing to the surfaces. This protein rich layer formed around NPs is called the "protein corona". Consequential interactions between NPs and proteins are governed due to the characteristics of the corona. The features of NPs such as the size, surface chemistry, charge are the critical factors influencing the behavior of protein corona. Molecular properties and protein corona composition affect the cellular uptake of NPs. Understanding and analyzing protein corona formation in relation to protein-NP properties, and elucidating its biological implications play an important role in bio-related nano-research studies. Protein-NP interactions have been studied extensively for the purpose of investigating the potential use of NPs as carriers in drug delivery systems. Further study should focus on exploring the effects of various characteristic parameters, such as the particle size, modifier type, temperature, pH on protein-NP interactions, providing toxicity information of novel NPs. In this contribution, important aspects related to protein corona forming, influential factors, novel findings and future perspectives on protein-NP interactions are overviewed.

Facile synthesis of nanogels modified Fe3O4@Ag NPs for the efficient adsorption of bovine & human serum albumin

This article describes the preparation of Fe₃O₄ nanoparticles and its decoration with a layer of tiny Ag nanoparticles at room temperature. Later on, the synthesized Fe₃O₄@Ag heterostructures were protected with Silica and finally modified with Poly(N-isopropyl acrylamide) (PNIPA) nanogels through post-synthesis method to get multifunctional (superparamagnetic, plasmonic and thermosensitive) nanocomposite. The structural characteristics of Fe₃O₄@Ag@SiO₂-PNIPA nanogels composite were investigated by instrumental techniques such as Transmission Electron Microscopy (TEM), Scanning Electron Microscopy (SEM), Fourier Transform Infrared Spectroscopy (FT-IR), X-ray Diffraction (XRD) and Vibrating Sample Magnetometer (VSM). The average particles diameter was calculated from XRD data through Scherer formula and it was found as 14 nm. The Fe₃O₄@Ag@SiO₂-PNIPA polymeric composites were assessed for the adsorption of Bovine Serum Albumin (BSA) and Human Serum Albumin (HSA) proteins from aqueous media. The adsorption data of BSA and HSA were best explained by Langmuir isotherm model with maximum adsorption capacities of 322 and 166 (mg/g) respectively showing mono-layer adsorption. The kinetics data for both the proteins were fairly interpreted by pseudo-second-order model. Thermodynamics studies revealed that the adsorption phenomena of BSA and HSA on the surface of Fe₃O₄@Ag@SiO₂-PNIPA nanogels composite are spontaneous and exothermic.

Immunomodulation of MSCs and MSC-Derived Extracellular Vesicles in Osteoarthritis

Osteoarthritis (OA) has become recognized as a low-grade inflammatory state. Inflammatory infiltration of the synovium by macrophages, T cells, B cells, and other immune cells is often observed in OA patients and plays a key role in the pathogenesis of OA. Hence, orchestrating the local inflammatory microenvironment and tissue regeneration microenvironment is important for the treatment of OA. Mesenchymal stem cells (MSCs) offer the potential for cartilage regeneration owing to their effective immunomodulatory properties and anti-inflammatory abilities. The paracrine effect, mediated by MSC-derived extracellular vehicles (EVs), has recently been suggested as a mechanism for their therapeutic properties. In this review, we summarize the interactions between MSCs or MSC-derived EVs and OA-related immune cells and discuss their therapeutic effects in OA. Additionally, we discuss the potential of MSC-derived EVs as a novel cell-free therapy approach for the clinical treatment of OA.

Recent Advances of Magnetic Nanomaterials in Bone Tissue Repair

The magnetic field has been proven to enhance bone tissue repair by affecting cell metabolic behavior. Magnetic nanoparticles are used as biomaterials due to their unique magnetic properties and good biocompatibility. Through endocytosis, entering the cell makes it easier to affect the physiological function of the cell. Once the magnetic particles are exposed to an external magnetic field, they will be rapidly magnetized. The magnetic particles and the magnetic field work together to enhance the effectiveness of their bone tissue repair treatment. This article reviews the common synthesis methods, the mechanism, and application of magnetic nanomaterials in the field of bone tissue repair.

Sorption of DONs onto clay minerals in single-solute and multi-solute systems: Implications for DONs mobility in the vadose zone and leachability into groundwater

Dissolved organic nitrogen (DON) with a mixture of various organic nitrogen (N) is recognized as an emerging groundwater contaminant. Investigating the behavior and mechanism of DON sorption onto clay minerals, which are key components of vadose zone media, is crucial to evaluating its leaching potential. Considering the interactions among multiple DON compounds (DONs) may influence their sorption behaviors, the sorption of three typical DONs (amino acid, protein and urea) to clay minerals in single-, binary- and ternary-solute systems were explored, respectively. In addition, a combination of multiple methods, including physiochemical characterization, Fourier Transform Infrared Spectroscopy (FTIR), X-ray diffraction (XRD) and pH variation analysis, were used to provide insight into the governing mechanisms. Results indicated that the sorption kinetics and isotherms of single systems were well-fitted by pseudo-second-order and Freundlich isotherm models, respectively. The mechanisms involved in the sorption of DONs onto clay minerals varied with the sorption time. The dominant interactions included van der Waals forces, ligand exchange, and hydrogen bonding (H-bonding) in the initial phase of the sorption process, whereas electrostatic interactions were predominant in the later stage as H⁺ was released into the solution. In binary-solute systems, either cooperative or competitive sorption was observed depending on the co-solute combination. For instance, the sorption behaviors of amino acids and urea were simultaneously enhanced in the binary system because of the formation of highly charged complexes as new active sites. Proteins sorption, however, was inhibited by the coexistence of urea as a result of active site depletion and protein denaturation. In ternary-solute systems, the sorption of DONs was balanced by cooperative and competitive sorption processes. These findings elucidated the sorption behaviors of DONs onto clay minerals in multi-solute systems and contributed to the evaluation of the mobility of DONs in the vadose zone and their leachability into groundwater.

Synthesis and characterization of magnetic chitosan microspheres for drug delivery

A novel magnetic microsphere was prepared by simple microemulsion polymerization for protein drug delivery systems. The Fe₃O₄ magnetic nanoparticles were successfully encapsulated in chitosan microspheres, which endowed the chitosan microspheres with good magnetism. The drug loading performance results indicated that the prepared magnetic chitosan microspheres exhibited a superior drug loading capacity, and the drug loading amount reached 947.01 mg g^-1. Furthermore, the magnetic chitosan microspheres also showed a higher drug release rate (87.8%) and evident sustained-release performance in vitro. The magnetic microsphere carrier will be widely used in the biomedical field as a promising drug carrier.

Preparation, Physical Characterization and Adsorption Properties of Synthesized Co–Ni–Cr Nanocomposites for Highly Effective Removal of Nitrate: Isotherms, Kinetics and Thermodynamic Studies

In the current effort, the Co–Ni–Cr Nanocomposites were synthesized by chemical method and characterized by means of scanning electron micrographs (SEM), X-ray diffraction (XRD), Fourier trans from infra-red (FTIR), and vibration sample magnetization (VSM). In the final step, these nanoparticles were used to study the nitrate removal efficiency from aqueous solution. The effect of important factor including pH, concentration of Nitrate (NO3 −) ion, contact time and nanoparticle dose were studied in order to find the optimum adsorption conditions. A maximum of removal of the nitrate was observed at pH 4, initial concentration of 40 mg L−1, amount of nanoparticle of 0.06 g L−1 and contact time 60 min. The adsorption isotherm values were obtained and analyzed using the Langmuir, Frenudlich, Temkin and Dubinin–Radushkevich equations, the Temkin isotherm being the one that showed the best correlation coefficient (R2 = 0.999). In addition to, the adsorption kinetics studied by the pseudo-first-order, pseudo-second-order, Elovich model, Ritchie and intraparticle diffusion models. The experimental data fitted to pseudo-second-order (R2 = 0.999).

Highly Tough, Biocompatible, and Magneto-Responsive Fe3O4/Laponite/PDMAAm Nanocomposite Hydrogels

Magneto-responsive hydrogels (MRHs) have attracted considerable attention in various applications owing to their smart response to an externally applied magnetic field. However, their practical uses in biomedical fields are limited by their weak mechanical properties and possible toxicity to the human body. In this study, tough, biocompatible, and magneto-responsive nanocomposite hydrogels (MR_NCHs) were developed by the in-situ free-radical polymerization of N, N-dimethylacrylamide (DMAAm) and laponite and Fe3O4 nanoparticles. The effects of the concentrations of DMAAm, water, and laponite and Fe3O4 nanoparticles in the pre-gel solutions or mixtures on the viscoelastic and mechanical properties of the corresponding hydrogels were examined by performing rheological and tensile tests, through which the mixture composition producing the best MR_NCH system was optimized. The effects were also explained by the possible network structures of the MR_NCHs. Moreover, the morphology, chemical structure, and thermal and mechanical properties of the MR_NCHs were analyzed, while comparing with those of the poly(DMAAm) (PDMAAm) hydrogels and laponite/PDMAAm NCHs. The obtained optimal MR_NCH exhibited noticeable magnetorheological (MR) behavior, excellent mechanical properties, and good biocompatibility. This study demonstrates how to optimize the best Fe3O4/laponite/PDMAAm MR_NCH system and its potential as a soft actuator for the pharmaceutical and biomedical applications.

Effective phosphorus removal using chitosan/Ca-organically modified montmorillonite beads in batch and fixed-bed column studies

In this study, phosphorus removal from aqueous solution was investigated using chitosan/Ca-organically modified montmorillonite (chitosan/Ca-OMMT) beads in batch and fixed-bed column systems. The XPS spectra confirmed that the calcium ions on the surface of the beads play a dominant role in capturing phosphate ions through surface complexation. The batch adsorption experimental data were fitted with pseudo-second-order kinetics and the Langmuir isotherm. The maximum adsorption capacity of the chitosan/Ca-OMMT beads was found to be 76.15 mg/g at an initial phosphate concentration of 100 mg/L at 25 °C. High phosphate uptake is achieved over the wide pH range 3-11, as well as in the presence of competing anions such as Cl^-, NO₃^-, SO₄^2-, and HCO₃^-. Furthermore, the chitosan/Ca-OMMT beads can be easily regenerated using 0.1 mol/L NaOH as a desorption agent with more than 83.97% adsorption capacity remaining after five adsorption/desorption cycles. The Thomas, Yoon-Nelson, and Adams-Bohart models were applied to the experimental data to predict the breakthrough curves using non-linear regression; the Yoon-Nelson model showing the best agreement with the breakthrough curves. These findings demonstrate that chitosan/Ca-OMMT beads can be used as a cost-effective and environment-friendly adsorbent for the removal of phosphate from wastewater.