Preparation and characterization of ß-lactoglobulin/poly(ethylene oxide) magnetic nanofibers for biomedical applications

Magnetic nanosystem a tool for targeted delivery and diagnostic application: Current challenges and recent advancement

Over the last two decades, researchers have paid more attention to magnetic nanosystems due to their wide application in diverse fields. The metal nanomaterials' antimicrobial and biocidal properties make them an essential nanosystem for biomedical applications. Moreover, the magnetic nanosystems could have also been used for diagnosis and treatment because of their magnetic, optical, and fluorescence properties. Superparamagnetic iron oxide nanoparticles (SPIONs) and quantum dots (QDs) are the most widely used magnetic nanosystems prepared by a simple process. By surface modification, researchers have recently been working on conjugating metals like silica, copper, and gold with magnetic nanosystems. This hybridization of the nanosystems modifies the structural characteristics of the nanomaterials and helps to improve their efficacy for targeted drug and gene delivery. The hybridization of metals with various nanomaterials like micelles, cubosomes, liposomes, and polymeric nanomaterials is gaining more interest due to their nanometer size range and nontoxic, biocompatible nature. Moreover, they have good injectability and higher targeting ability by accumulation at the target site by application of an external magnetic field. The present article discussed the magnetic nanosystem in more detail regarding their structure, properties, interaction with the biological system, and diagnostic applications.

Recent advances in electrospun protein fibers/nanofibers for the food and biomedical applications

Electrospinning (ES) is one of the most investigated processes for the convenient, adaptive, and scalable manufacturing of nano/micro/macro-fibers. With this technique, virgin and composite fibers may be made in different designs using a wide range of polymers (both natural and synthetic). Electrospun protein fibers (EPF) shave desirable capabilities such as biocompatibility, low toxicity, degradability, and solvolysis. However, issues with the proteins' processibility have limited their widespread utilization. This paper gives an overview of the features of protein-based biomaterials, which are already being employed and has the potential to be exploited for ES. State-of-the-art examples showcasing the usefulness of EPFs in the food and biomedical industries, including tissue engineering, wound dressings, and drug delivery, provided in the applications. The EPFs' future perspective and the challenge they pose are presented at the end. It is believed that protein and biopolymeric nanofibers will soon be manufactured on an industrial scale owing to the limitations of employing synthetic materials, as well as enormous potential of nanofibers in other fields, such as active food packaging, regenerative medicine, drug delivery, cosmetic, and filtration.

Mg.ATP-decorated ultrafine magnetic nanofibers: A bone scaffold with high osteogenic and antibacterial properties in the presence of an electromagnetic field

In this study, ultrafine magnetic nanofibers were developed for bone regeneration purposes. Nanofibers were acquired by electrospinning using a two-component nanofiber matrix (CP: chitosan (Cs) and polyvinyl alcohol (PVA)) containing different concentrations of succinate conjugated-magnetic hydroxyapatite nanocomposites (SMHA). Hybrid nanofibers (CP&SMHA) containing 5 mg ml^-1 of SMHA nanocomposite showed well-defined properties in terms of physicochemical properties and cell behavior. Then, they were modified with adenosine 5'-triphosphate (ATP) and Mg²⁺ ions. The initial adhesion of mesenchymal stem cells and their proliferation rate on the surface of modified nanofibers (Mg.ATP.CP&SMHA) were significantly increased as compared to those of bare nanofibers. Analysis of common osteogenic markers such as alkaline phosphatase activity and the expression of Runt-related transcription factor 2 and osteocalcin confirmed the osteogenic efficacy enhancement of CP&SMHA nanofibers when they were functionalized with ATP and Mg²⁺. The utilization of the antagonist of purine receptor, P2X7, revealed that this receptor has a major role in the osteogenesis process induced by Mg.ATP.CP&SMHA. Moreover, the results showed that cell adhesion, proliferation, and differentiation improved as nanofibers were under the influence of the electromagnetic field (EMF), displaying synergistic effects in the process of bone formation. Mg.ATP.CP&SMHA also showed an antibacterial effect against gram-negative and gram-positive bacteria, Escherichia coli and Staphylococcus aureus, respectively. Considering the high osteogenic potential and antibacterial activity of Mg.ATP.CP&SMHA nanofibers particularly in combination with EMF, it can serve as a great candidate for use in bone tissue engineering applications.

Electrospinning Proteins for Wound Healing Purposes: Opportunities and Challenges

With the growth of the aging population worldwide, chronic wounds represent an increasing burden to healthcare systems. Wound healing is complex and not only affected by the patient's physiological conditions, but also by bacterial infections and inflammation, which delay wound closure and re-epithelialization. In recent years, there has been a growing interest for electrospun polymeric wound dressings with fiber diameters in the nano- and micrometer range. Such wound dressings display a number of properties, which support and accelerate wound healing. For instance, they provide physical and mechanical protection, exhibit a high surface area, allow gas exchange, are cytocompatible and biodegradable, resemble the structure of the native extracellular matrix, and deliver antibacterial agents locally into the wound. This review paper gives an overview on cytocompatible and biodegradable fibrous wound dressings obtained by electrospinning proteins and peptides of animal and plant origin in recent years. Focus is placed on the requirements for the fabrication of such drug delivery systems by electrospinning as well as their wound healing properties and therapeutic potential. Moreover, the incorporation of antimicrobial agents into the fibers or their attachment onto the fiber surface as well as their antimicrobial activity are discussed.

Magnetic Properties of Electrospun Magnetic Nanofiber Mats after Stabilization and Carbonization

Magnetic nanofibers are of great interest in basic research, as well as for possible applications in spintronics and neuromorphic computing. Here we report on the preparation of magnetic nanofiber mats by electrospinning polyacrylonitrile (PAN)/nanoparticle solutions, creating a network of arbitrarily oriented nanofibers with a high aspect ratio. Since PAN is a typical precursor for carbon, the magnetic nanofiber mats were stabilized and carbonized after electrospinning. The magnetic properties of nanofiber mats containing magnetite or nickel ferrite nanoparticles were found to depend on the nanoparticle diameters and the potential after-treatment, as compared with raw nanofiber mats. Micromagnetic simulations underlined the different properties of both magnetic materials. Atomic force microscopy and scanning electron microscopy images revealed nearly unchanged morphologies after stabilization without mechanical fixation, which is in strong contrast to pure PAN nanofiber mats. While carbonization at 500 °C left the morphology unaltered, as compared with the stabilized samples, stronger connections between adjacent fibers were formed during carbonization at 800 °C, which may be supportive of magnetic data transmission.