A modified microemulsion method for fabrication of hydrogel Tragacanth nanofibers

Microbial cellulosic pad encompassing alpha-arbutin in Tragacanth gum as the controlled delivery system

This research focuses on preparing a natural-based drug delivery system for α-arbutin (AR) as a skin lightening. Bacterial cellulose nanofibers (BC) pad was used for controlled-AR release through two approaches. First was the dip-drying method (P-BC), in which AR cross-linked to BC pads using citric acid (CA). The second was simultaneously entrapping of AR in Tragacanth gum (AR-TG) and stabilized on BC (BC-T) through the ultrasonic-assisted microemulsion method. UV-Vis spectra revealed better control of AR release in BC-T in the first hour. High cell viability (above 70 %) of the pads containing 1-3 % AR was reported using MTT assay. The in-vitro permeation study indicated the proper AR penetration in the treated pads. The Fickian diffusion model was determined as a fitted model for all pads in the drug release kinetics. FTIR, XRD, and TGA analyses further characterized the pads. FESEM images verified AR-TG and BC structures with average diameters of 410.7 ± 25.4 and 34.5 ± 7.51 nm, respectively. The hydrophilicity and mechanical properties of the pads were also investigated. Finally, the high biocompatibility, initial controlled release, and proper permeation suggested BC-T as a more promising delivery platform for AR.

Exploring Various Techniques for the Chemical and Biological Synthesis of Polymeric Nanoparticles

Nanoparticles (NPs) have remarkable properties for delivering therapeutic drugs to the body's targeted cells. NPs have shown to be significantly more efficient as drug delivery carriers than micron-sized particles, which are quickly eliminated by the immune system. Biopolymer-based polymeric nanoparticles (PNPs) are colloidal systems composed of either natural or synthetic polymers and can be synthesized by the direct polymerization of monomers (e.g., emulsion polymerization, surfactant-free emulsion polymerization, mini-emulsion polymerization, micro-emulsion polymerization, and microbial polymerization) or by the dispersion of preformed polymers (e.g., nanoprecipitation, emulsification solvent evaporation, emulsification solvent diffusion, and salting-out). The desired characteristics of NPs and their target applications are determining factors in the choice of method used for their production. This review article aims to shed light on the different methods employed for the production of PNPs and to discuss the effect of experimental parameters on the physicochemical properties of PNPs. Thus, this review highlights specific properties of PNPs that can be tailored to be employed as drug carriers, especially in hospitals for point-of-care diagnostics for targeted therapies.

Recent advances in biochar engineering for soil contaminated with complex chemical mixtures: Remediation strategies and future perspectives

Heavy metal/metalloids (HMs) and polycyclic aromatic hydrocarbons (PAHs) in soil have caused serious environmental problems, compromised agriculture quality, and have detrimental effects on all forms of life including humans. There is a need to develop appropriate and effective remediation methods to resolve combined contaminated problems. Although conventional technologies exist to tackle contaminated soils, application of biochar as an effective renewable adsorbent for enhanced bioremediation is considered by many scientific researchers as a promising strategy to mitigate HM/PAH co-contaminated soils. This review aims to: (i) provide an overview of biochar preparation and its application, and (ii) critically discuss and examine the prospects of (bio)engineered biochar for enhancing HMs/PAHs co-remediation efficacy by reducing their mobility and bioavailability. The adsorption effectiveness of a biochar largely depends on the type of biomass material, carbonisation method and pyrolysis conditions. Biochar induced soil immobilise and remove metal ions via various mechanisms including electrostatic attractions, ion exchange, complexation and precipitation. PAHs remediation mechanisms are achieved via pore filling, hydrophobic effect, electrostatic attraction, hydrogen bond and partitioning. During last decade, biochar engineering (modification) via biological and chemical approaches to enhance contaminant removal efficiency has garnered greater interests. Hence, the development and application of (bio)engineered biochars in risk management, contaminant management associated with HM/PAH co-contaminated soil. In terms of (bio)engineered biochar, we review the prospects of amalgamating biochar with hydrogel, digestate and bioaugmentation to produce biochar composites.

Physicomechanical, rheological and in vitro cytocompatibility properties of the electron beam irradiated blend hydrogels of tyramine conjugated gum tragacanth and poly (vinyl alcohol)

In the present study, preparation of blend hydrogels of tyramine conjugated gum tragacanth and poly (vinyl alcohol) was carried out by electron beam irradiation, and modification of hydrogel properties with poly (vinyl alcohol) was demonstrated. Gel content, swelling behavior, pore size and mechanical and rheological properties of hydrogels prepared at 14, 28 and 56 kilogray (kGy) with different ratios of polymers were investigated. Gel content increased from 67 ± 2% for pure tyramine conjugated gum tragacanth hydrogel to >92% for blend hydrogels. However, the corresponding equilibrium swelling degree decreased from 35.21 ± 1.51 to 9.14 ± 1.66 due to the higher crosslink density of blend hydrogel. The mechanical strength of the hydrogels with interconnected pores increased significantly in the presence of poly (vinyl alcohol) and increasing irradiation dose up to 28 kGy with a twenty-fold enhancement of stress fracture and excellent elastic recovery in cyclic compression analysis. The equilibrium swelling degree of blend hydrogel containing 3% w/v tyramine conjugated gum tragacanth and 2% w/v poly (vinyl alcohol) prepared at 28 kGy was 16.59 ± 0.81. The biocompatibility of hydrogels was tested in the presence of rabbit bone marrow mesenchymal stem cells. The viability of cells exposed to hydrogel extract was >92% after 7 days of culture and indicated hydrogel biocompatibility with potential biomedical applications.

The removal of nickel and lead ions from aqueous solutions using green synthesized silica microparticles

Silica microparticles were synthesized from sugarcane bagasse via a green synthetic technique. The prepared silica microparticles were used to remove lead and nickel ions from their separate solutions. Microscopic analysis shows that the synthesized silica particles are spherical with good monodispersed properties. The average particle diameter of the silica microparticles is estimated to be about 432 nm. Batch adsorption experiment was employed to examine the influence of adsorbent dosage, contact time, heavy metal ion concentration and pH on the adsorption efficiency of the synthesized silica microparticles in removing the studied lead (Pb²⁺) and nickel (Ni²⁺) ions from their respective solutions. An increase in adsorbent dosage, heavy metal ion concentration, contact time and pH led to an increase in the percentage removal of Pb²⁺ and Ni²⁺ metal ions from their individual solutions. The adsorption process of Pb²⁺ ion onto the synthesized silica microparticles followed the Langmuir adsorption isotherm (R² = 0.961), while, the nickel ion (Ni²⁺) followed the Freundlich isotherm (R² = 0.869). The adsorption process of the studied heavy metals (Pb²⁺ and Ni²⁺) in their separate solutions favours pseudo-second-order reaction model (R², 0.978 and 0.999) over the pseudo-first-order reaction model.

One-pot reactive electrospinning of chitosan/PVA hydrogel nanofibers reinforced by halloysite nanotubes with enhanced fibroblast cell attachment for skin tissue regeneration

In this study, in situ glyoxal crosslinked chitosan/poly (vinyl alcohol) (PVA) hydrogel nanofibers reinforced with halloysite nanotubes (HNT) were prepared by the electrospinning method without needing post-treatment for stabilization of the nanofibers in aqueous media. FTIR spectroscopy approved the formation of acetal bonds between glyoxal and hydroxyl groups of PVA and chitosan. Morphological studies by SEM/EDX and TEM in accordance with XRD patterns proved that HNT was successfully incorporated into the crosslinked chitosan/PVA nanofibers. The crosslinked nanofibers were insoluble in water. Due to the hydrophilic nature of HNT, the swelling of the nanofibers was increased from 272% for crosslinked chitosan/PVA nanofibers to around 400% for the HNT reinforced nanocomposite nanofibers. Comparing to chitosan/PVA nanofibers, the tensile strength of the crosslinked nanocomposite nanofibers was increased to 2.4 and 3.5 fold by incorporation of 3 and 5% HNT, respectively. Presence of HNT in chitosan/PVA nanofibers reduced the contact angle with water and increased the hydrophilicity of HNT-reinforced nanofibers favoring the attachment of fibroblast cells. Cytotoxicity studies by AlamarBlue assay showed that presence of HNT increased the biocompatibility of the nanofibers. It was also concluded that glyoxal can be used safely for crosslinking of chitosan/PVA nanofibers without any cytotoxic effect for fibroblast cells. From the results of this work, HNT reinforced chitosan/PVA nanofibers crosslinked by glyoxal are introduced as promising nanomaterials for skin tissue regeneration.

Recent progress in the industrial and biomedical applications of tragacanth gum: A review

Natural polymers have distinct advantages over synthetic polymers because of their abundance, biocompatibility, and biodegradability. Tragacanth gum, an anionic polysaccharide, is a natural polymer which is derived from renewable sources. As a biomaterial, tragacanth gum has been used in industrial settings such as food packaging and water treatment, as well as in the biomedical field as drug carriers and for wound healing purposes. The present review provides an overview on the state-of-the-art in the field of tragacanth gum applications. The structure, properties, cytotoxicity, and degradability as well as the recent advances in industrial and biomedical applications of tragacanth gum are reviewed to offer a backdrop for future research.

Review on recent progress in chitosan-based hydrogels for wastewater treatment application

Recently, chitosan has been used as a raw material for synthesis of hydrogels in a wide range of potential and practical applications like wastewater treatment, drug delivery, and tissue engineering. This review represents an overview of the application of chitosan-based hydrogels for wastewater treatment and helps researchers to better understand the potential of these adsorbents for wastewater treatment. It covers recently used and prospected methods for synthesis and modification of these hydrogels. Chitosan-based hydrogels are modified physically and chemically through crosslinking, grafting, impregnation, incorporating of hard fillers, blending, interpenetrating, and ion-imprinting methods to improve adsorption and mechanical properties. Understanding of these methods provides useful information in the design of efficient chitosan-based hydrogels and the select of appropriate pollutants for removal. This review provides a brief outlook on future prospects of chitosan-based hydrogels for wastewater application.