Poly(methacrylic acid-co-vinyl sulfonic acid)-grafted-magnetite/nanocellulose superabsorbent composite for the selective recovery and separation of immunoglobulin from aqueous solutions

Functional network copolymeric hydrogels derived from moringa gum: Physiochemical, drug delivery and biomedical properties

The article explores the synthesis of network hydrogels derived from moringa gum (MG) through a grafting reaction with poly (vinylsulfonic acid) and carbopol. These hydrogels are designed for use in drug delivery (DD) and wound hydrogels dressing (HYDR) applications. The copolymers were characterized by FESEM, EDX, AFM, FTIR, 13C NMR, XRD and DSC. Tetracycline release from hydrogel occurred gradually with a non-Fickian diffusion and was best described by the Hixson-Crowell kinetic model in artificial wound fluid. The HYDR demonstrated compatibility with blood, exhibited antioxidant properties and possessed tensile strength, in addition to their mucoadhesive characteristics. The copolymer dressings absorbed approximately 7 g of simulated fluid. The copolymers exhibited significant antioxidant activity, measuring at 84 % free radicals scavenging, during DPPH assay. These dressings demonstrated permeability to H2O and O2,. The hydrogel alone did not reveal antibacterial activities; however, when combined with antibiotic drug tetracycline, the dressings revealed notable antibacterial activities against Staphylococcus aureus, Pseudomonas aeruginosa and Escherichia coli. The observed biomedical properties suggested that these hydrogels could serve as promising materials for drug delivery HYDR applications.

Sulfonic acid functionalized cellulose-derived (nano)materials: Synthesis and application

The preparation/application of heterogeneous (nano)materials from natural resources has currently become increasingly fascinating for researchers. Cellulose is the most abundant renewable polysaccharide on earth. The unique physicochemical, structural, biological, and environmental properties of this natural biopolymer have led to its increased application in many fields. The more desirable features of cellulose-based (nano)materials such as biodegradability, renewability, biocompatibility, cost-effectiveness, simplicity of preparation, environmentally friendly nature, and widespread range of applications have converted them into promising compounds in medicine, catalysis, biofuel cells, and water/wastewater treatment processes. Functionalized cellulose-based (nano)materials containing sulfonic acid groups may prove to be one of the most promising sustainable bio(nano)materials of modern times in the field of cellulose science and (nano)technology owing to their intrinsic features, high crystallinity, high specific surface area, abundance, reactivity, and recyclability. In this review, the developments in the application of sulfonated cellulose-based (nano)materials containing sulfonic acid (-SO3H) groups in catalysis, water purification, biological/biomedical, environmental, and fuel cell applications have been reported. This review provides an overview of the methods used to chemically modify cellulose and/or cellulose derivatives in different forms, including nanocrystals, hydrogels, films/membranes, and (nano)composites/blends by introducing sulfonate groups on the cellulose backbone, focusing on diverse sulfonating agents utilized and substitution regioselectivity, and highlights their potential applications in different industries for the generation of alternative energies and products.

Electric Field-Assisted Molecularly Imprinted Polymer-Modified QCM Sensor for Enhanced Detection of Immunoglobulin

In this study, an electric-field-assisted molecularly imprinted polymer (EFAMIP) as an enhanced form of MIP was developed to improve the MIP-modified quartz crystal microbalance (QCM) biosensors. While exerting a vertical electric field, polymerization of methacrylic acid in the presence of immunoglobulin G (IgG) as the template was initiated, and later, after the template removal process, the EFAMIPs were obtained. The polymer surface characterization was conducted by using a scanning electron microscope. The impact of electric field direction on IgG binding sites, forming either EFAMIP-Fab or EFAMIP-Fc, was assessed. Next, the static measurement results in liquid for EFAMIP-modified QCM and MIP-modified QCM were compared. While encompassing IgG, EFAMIP-modified QCMs exhibited up to a 113.5% higher frequency shift than typical MIP in time-limited detection. The final frequency shift of EFAMIP, which determines the detection limit of IgG, was improved up to 12.5% compared to typical MIP. Moreover, the EFAMIP-Fab performance was promising for the selective detection of IgG in a solution containing different types of immunoglobulins.

Structural Characterization of Nanocellulose/Fe3O4 Hybrid Nanomaterials

The rise of innovation in the electrical industry is driven by the controlled design of new materials. The hybrid materials based on magnetite/nanocellulose are highly interesting due to their various applications in medicine, ecology, catalysis and electronics. In this study, the structure and morphology of nanocellulose/magnetite hybrid nanomaterials were investigated. The effect of nanocellulose loading on the crystal structure of synthesized composites was investigated by XRD and FTIR methods. The presented study reveals that the interaction between the cellulose and magnetic nanoparticles depends on the nanocellulose content. Further, a transition from cellulose II to cellulose I allomorph is observed. SEM and EDS are employed to determine the variation in morphology with changes in component concentrations. By the calculation of magnetic interactions between adjacent Fe³⁺ and Fe²⁺ ions within composites, it is determined that ferromagnetic coupling predominates.

The Influence of Monomer Composition and Surface-CrossLinking Condition on Biodegradation and Gel Strength of Super Absorbent Polymer

In this study, a superabsorbent polymer (SAP) comprising poly (IA-co-cellulose-co-VSA-co-AA; ICVA) core-SAP (CSAP) was synthesized through radical polymerization using itaconic acid (IA), acrylic acid (AA), cellulose, and vinyl sulfonic acid (VSA) as monomers. The absorption performances and relative biodegradability of various compositions prepared by adjusting the amounts of cellulose and VSA with constant IA and AA content were compared. Increasing the cellulose content in CSAP contributed to improved biodegradation of the surface-crosslinked SAP (SSAP) and gel strength, although the free absorbency (FA) and centrifuge retention capacity (CRC) decreased. Increasing the VSA content resulted in strong anionicity, which enables the absorption of large amounts of water. Surface-crosslinking technology was applied to the CSAP synthesized with the optimal composition ratio to increase its absorption performance and gel strength. Improved performance of the synthesized SSAP (a CRC of 30.4 g/g, absorbency under load (AUL) of 23.3 g/g, and permeability of 55 s) was achieved by selecting the optimal surface-crosslinking treatment time and the amount of distilled water in the surface-crosslinking solution: as the latter was increased in the surface-crosslinking solution, the AUL and permeability of the SSAP were improved, and its biodegradability was found to be 54% compared to the 100% biodegradable cellulose hydrogel in the control group.

Target-Specific Superparamagnetic Hydrogel with Excellent pH Sensitivity and Reversibility: A Promising Platform for Biomedical Applications

Superparamagnetism has been widely used for many biomedical applications, such as early detection of inflammatory cancer and diabetes, magnetic resonance imaging (MRI), hyperthermia, etc., whereas incorporation of superparamagnetism in stimulus-responsive hydrogels has now gained substantial interest and attention for application in these fields. Recently, pH-responsive superparamagnetic hydrogels showing the potential use in disease diagnosis, biosensors, polymeric drug carriers, and implantable devices, have been developed based on the fact that pH is an important environmental factor in the body and some disease states manifest themselves by a change in the pH value. However, improvement in pH sensitivity of magnetic hydrogels is a dire need for their practical applications. In this study, we report the distinctly high pH sensitivity of new synthesized dual-responsive magnetic hydrogel nanocomposites, which was accomplished by copolymerization (free-radical polymerization) of two pH-sensitive monomers, acrylic acid (AA) and vinylsulfonic acid (VSA) with an optimum ratio, in the presence of presynthesized superparamagnetic iron oxide nanoparticles (Fe3O4(OH) x ). The monomers contain pH-sensitive functional groups (COO- and SO3 - for AA and VSA, respectively), and they have also been widely used as biomaterials because of the good biocompatibility. The pH sensitivity of the superparamagnetic hydrogel, poly(acrylic acid-co-vinylsulfonic acid), PAAVSA/Fe3O4, was investigated by swelling studies at different pH values from pH 7 to 1.4. Distinct pH reversibility of the system was also demonstrated through swelling/deswelling analysis. Thermal stability, chemical configuration, magnetic response, and structural properties of the system have been explored by suitable characterization techniques. Furthermore, the study reveals a pH-responsive significant change in the overall morphology and packing fraction of iron oxide nanoparticles in PAAVSA/Fe3O4 via energy-dispersive X-ray (EDX) elemental mapping with the field emission scanning electron microscopy (FESEM) study (for freeze-dried PAAVSA/Fe3O4, swelled at different pH values), implying a drastic change in susceptibility and induced saturation magnetization of the system. These important features could be easily utilized for the purpose of diagnosis using magnetic probe and/or impedance analysis techniques.

Controlled pesticide release of a novel superabsorbent by grafting citric acid onto water hyacinth powders with the assistance of dopamine

To treat the presence of abundant water hyacinth, increase biodegradability and reduce cost of water-absorbing material, CA–PD@WH composite was fabricated by chemical modification of dopamine-coated water hyacinth with citric acid.

Synthesis and properties of the rapeseed meal-grafted-poly(methyl methacrylate-co-butyl acrylate) oil-absorbents

Economical RSMs-g-P(MMA-co-BA) oil-absorbents with 3D network structures were prepared through free radical graft copolymerization, which exhibited good oil absorbency, reusability and were applied to oil/water separation.

Synthesis of polydopamine-coated halloysite nanotube-based hydrogel for controlled release of a calcium channel blocker

A stimuli-triggered drug delivery vehicle has been synthesized by self-polymerization of dopamine (DA) on the outer surface of halloysite nanotubes (HNT) followed by gelationviaalginate.