Preparation and characterization of electrospun polyacrylonitrile fiber mats containing Garcinia mangostana

A comprehensive review on preparation, functionalization and recent applications of nanofiber membranes in wastewater treatment

The direct discharge of significant amounts of polluted water into water bodies causes adverse ecological and human health effects. This severe deterioration in water quality creates significant challenges to meet the growing demand for clean water. Therefore, the world urgently needs environmentally friendly advanced technology to overcome this global crisis. In this regard, nanofiber-based membrane filtration is a promising technique in wastewater remediation because of their huge surface area, extremely porous structure, amenable pore size/pore size distribution, variety of material choices, and flexibility to modification with other functional materials. However, despite their unique properties, fouling, poor mechanical properties, shrinkage, and deformation are major drawbacks of nanofiber membranes for treating wastewater. This review presents a comprehensive overview of nanofiber membranes' fabrication and function in water purification applications as well as providing novel approaches to overcoming/alleviating the mentioned disadvantages. The review first presents nanofiber membrane preparation methods, focusing on electrospinning as a versatile and viable technique alongside discussing the parameters controlling nanofiber morphology. Afterward, the functionalization of nanofiber membranes by combining them with other nanomaterials, such as metal and metal-oxide nanoparticles, carbon nanotubes, metal-organic frameworks, and biomolecules, were demonstrated and discussed. In addition, nanofiber membranes functionalized with microorganisms were highlighted. Finally, we introduced and discussed in detail the most relevant and recent advances in nanofiber applications in wastewater treatment in the context of removing different pollutants (e.g., heavy metals, nutrients, radioactive elements, pharmaceuticals, and personal care products, dyes, and pesticides). Moreover, the promising antimicrobial ability of nanofiber membranes in removing microorganisms from wastewater has been fully underscored. We believe this comprehensive review could provide researchers with preliminary data and guide both researchers and producers engaged in the nanofiber membrane industry, letting them focus on the research gaps in wastewater treatment.

Valorization of mangosteen, "The Queen of Fruits," and new advances in postharvest and in food and engineering applications: A review

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This review highlights recent advances of mangosteen research in the postharvest, food and engineering fields.

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In postharvest fields, phytohormones, metabolites, and pest/disease management are described.

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Mangosteen has also been used in various food products and for animal feed supplementation.

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In engineering, mangosteen extract is useful in solar cells, carbon dots and advanced materials.

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Mangosteen-based products may benefit consumers and the engineering and biomedical industries.

One of the most prolific plants utilized in various applications is mangosteen (Garcinia mangostana L.). Rich in potent bioactive compounds, such as xanthones, mangosteen is known to possess pharmacologically important anti-inflammatory and anti-tumor properties. However, most previous reviews have only discussed the application of mangosteen in medicinal areas, yet more recent studies have diverged and valorized its usage in other scientific fields. In this review, the utilization of this exotic fruit in postharvest biology (phytohormone roles, metabolite profiling, bioactive compounds, isolation method optimization, chemical contaminant identification, and management of pests and fruit disorders), food science (food products, animal feed supplementation, and food shelf-life determination), and engineering fields (fabric and solar cell dyes, carbon dots, activated carbon, and biomedical advanced materials) is presented in detail. Research papers published from 2016 onward were selected and reviewed to show the recent research trends in these areas. In conclusion, mangosteen has been utilized for various purposes, ranging from usage in industrially important products to applications in advanced technologies and biomedical innovation.

Poly-ε-Caprolactone/Gelatin Hybrid Electrospun Composite Nanofibrous Mats Containing Ultrasound Assisted Herbal Extract: Antimicrobial and Cell Proliferation Study

Electrospun fibers have emerged as promising materials in the field of biomedicine, due to their superior physical and cell supportive properties. In particular, electrospun mats are being developed for advanced wound dressing applications. Such applications require the firers to possess excellent antimicrobial properties in order to inhibit potential microbial colonization from resident and non-resident bacteria. In this study, we have developed Poly-ε-Caprolactone /gelatin hybrid composite mats loaded with natural herbal extract (Gymnema sylvestre) to prevent bacterial colonization. As-spun scaffolds exhibited good wettability and desirable mechanical properties retaining their fibrous structure after immersing them in phosphate buffered saline (pH 7.2) for up to 30 days. The initial burst release of Gymnema sylvestre prevented the colonization of bacteria as confirmed by the radial disc diffusion assay. Furthermore, the electrospun mats promoted cellular attachment, spreading and proliferation of human primary dermal fibroblasts and cultured keratinocytes, which are crucial parenchymal cell-types involved in the skin recovery process. Overall these results demonstrated the utility of Gymnema sylvestre impregnated electrospun PCL/Gelatin nanofibrous mats as an effective antimicrobial wound dressing.

Sonication induced effective approach for coloration of compact polyacrylonitrile (PAN) nanofibers

We present our research on dyeability of polyacrylonitrile (PAN) nanofibers following ultrasonic dyeing method. Although PAN has been extensively utilized in textile apparel, sportswear, upholstery and home furnishing, however, coloration of PAN nanofibers has not yet been reported. PAN is a compact fiber while the nanofiber structure makes it more difficult to color PAN nanofibers. PAN is generally dyed with basic dyes and dyeing is carried out in acidic conditions, while the dyeing process takes about two hours at boiling temperature. A systematic study on dyeability of PAN nanofibers will extend its use in textile apparel industry. Thus, we used ultrasonic energy and first time conducted our research on dyeability of electrospun PAN nanofibers using disperse dyes. Dyeing process parameters such as dyeing time, temperatures and concentrations of dyes were optimized. Ultrasonic dyeing of PAN nanofibers was compared with its conventional dyeing as well. Affect of ultrasonic dyeing on the morphology, chemical state, crystallographic structure and mechanical strength of PAN nanofibers has been studied. PAN nanofiber samples were characterized by SEM, FTIR, XRD and tensile strength tests. The results revealed 80 °C and 60 min as optimum temperature and time for ultrasonic dyeing of PAN nanofibers. The ultrasonic dyeing does not affect morphology, chemical and crystalline structure of the PAN nanofibers while it improves their mechanical strength. Our research suggests dyeability of PAN nanofibers with disperse dyes by ultrasonic method and their subsequent use in textile apparels.

Antimicrobial and Wound Healing Properties of Polyacrylonitrile-Moringa Extract Nanofibers

A simple and cost-effective material composed of polyacrylonitrile nanofibers containing different concentrations of moringa (MR) leaf extracts was fabricated for antimicrobial properties and wound dressing. The fabricated materials were characterized by scanning electron microscopy, thermal gravimetric analysis, and Fourier transmission infrared spectroscopy. The antibacterial sensitivity of the developed polyacrylonitrile-moringa extract nanofibers was evaluated against Staphylococcus aureus and Escherichia coli by the agar diffusion method. A pronounced antibacterial activity was observed with the increase in the incorporated moringa leaf extract concentration within the polyacrylonitrile-moringa extract nanofibers against the bacterial strains. The best antibacterial sensitivity was observed for nanofibers containing 0.5 g of moringa leaf extract which had an inhibitory zone of 15 mm for E. coli and 12 mm for S. aureus. Furthermore, the cost-effective and biodegradable nanofibrous polyacrylonitrile-moringa extract nanofiber was also used to conduct further studies regarding wound dressing. The result reveals that the increase in the concentrations of moringa leaf extract influenced the healing properties of the material. For days 1, 4, and 7 of the wound dressing experiment, the % wound closure of the rat was the highest for the nanofiber containing 0.5 g of moringa leaf extract (35, 87, and 95%, respectively) compared to the positive control medical gauze (29, 75, and 93%, respectively).