Biodegradable Composite Nanofiber Containing Fish-Scale Extracts

Biodegradable electrospun fibers as sustained-release carriers of insect pheromones for field trapping of Spodoptera litura (Lepidoptera: Noctuidae)

BACKGROUND

Insect pheromones are highly effective and environmentally friendly, and are widely used in the monitoring and trapping of pests. However, many researchers have found that various factors such as ultraviolet light and temperature in the field environment can accelerate the volatilization of pheromones, thus affecting the actual control effect. In recent years, electrospinning technology has demonstrated remarkable potential in the preparation of sustained carriers. Moreover, the utilization of biodegradable materials in electrospinning presents a promising avenue for the advancement of eco-friendly carriers.

RESULTS

In this study, homogeneous and defect-free pheromone carriers were obtained by electrospinning using fully biodegradable polyhydroxybutyrate materials and pheromones of Spodoptera litura. The electrospun fibers with porous structure could continuously release pheromone (the longest can be ≤80 days). They also had low light transmission, hydrophobic protection. More importantly, the pheromone-loaded electrospun fiber carriers showed stable release and good trapping effect in the field. They could trap pests for at least 7 weeks in the field environment without other light stabilizers added.

CONCLUSION

Sustained-release carriers constructed by electrospinning and green materials could improve the efficacy of pheromones and ensure environmental friendliness, and provided a tool for the management of S. litura and other pests and sustainable development of agricultural. © 2023 Society of Chemical Industry.

pH-sensitive cellulose/chitin nanofibrillar hydrogel for dye pollutant removal

In this study, a pH-sensitive smart hydrogel was successfully prepared by combining a polyelectrolyte complex using biopolymeric nanofibrils. By adding a green citric acid cross-linking agent to the formed chitin and cellulose-derived nanofibrillar polyelectrolytic complex, a hydrogel with excellent structural stability could be prepared even in a water environment, and all processes were conducted in an aqueous system. The prepared biopolymeric nanofibrillar hydrogel not only enables rapid conversion of swelling degree and surface charge according to pH but can also effectively remove ionic contaminants. The ionic dye removal capacity was 372.0 mg/g for anionic AO and 140.5 mg/g for cationic MB. The surface charge conversion ability according to pH could be easily applied to the desorption of the removed contaminants, and as a result, it showed an excellent contaminant removal efficiency of 95.1 % or more even in the repeated reuse process 5 times. Overall, the eco-friendly biopolymeric nanofibrillar pH-sensitive hydrogel shows potential for complex wastewater treatment and long-term use.

Fish-scale waste to portable bioactive discs: a sustainable platform for sensitive and reliable blood group analysis

Blood group analysis has evolved from conventional "test-tube" to ingenious "lab-on-a-chip" micro/paper-fluidic devices for identifying blood phenotypes. Despite the rapid and economical fabrication of these devices, they require Whatman paper that is obtained by cutting down trees and plastic usage involving complex and sophisticated facilities, making scalable manufacturing laborious and expensive. Most importantly, deforestation and plastic incineration pose great threats to the biotic and abiotic environments. Here, we have developed a blood grouping strip utilizing fish-scale waste and household cardboard-waste generated origami as an affordable and sustainable strategy. The naturally inherited hydrophilicity of fish scale with a contact angle of 89° could succinctly auto-stabilize low-volume antisera without the aid of additives. Moreover, unlike paperfluidics, antisera absorption, as well as RBC-antisera agglutination upon blood introduction, happens on the spot with no capillary wicking. The merits of our technique are: it requires a low amount of blood (3 μL), eliminates additional image processing and assays, is equipment-free, and aids accurate blood typing as a visual hemagglutination readout. Additionally, a high tensile strength of ∼85 ± 5 MPa and the shelf-endurance of the bio-disc allowed us to use the simplest cardboard origami as a shield, obviating plastic and fiber generated fancy shields, making our device portable and simultaneously biodegradable. Our novel bio-disc blood analysis was tested with anonymous blood samples (n = 200), with an accuracy comparable to a standard blood group assay. This zero-cost paper, plastic-free eco-friendly blood group analyser derived from biodegradable food and cardboard waste as a resourceful technique has huge potential in various sensors and point-of-care diagnostics, especially in impoverished areas with limited or no lab facilities.

Electrospinning as a Promising Process to Preserve the Quality and Safety of Meat and Meat Products

Fresh and processed meat products are staple foods worldwide. However, these products are considered perishable foods and their deterioration depends partly on the inner and external properties of meat. Beyond conventional meat preservation approaches, electrospinning has emerged as a novel effective alternative to develop active and intelligent packaging. Thus, this review aims to discuss the advantages and shortcomings of electrospinning application for quality and safety preservation of meat and processed meat products. Electrospun fibres are very versatile, and their features can be modulated to deliver functional properties such as antioxidant and antimicrobial effects resulting in shelf-life extension and in some cases product quality improvement. Compared to conventional processes, electrospun fibres provide advantages such as casting and coating in the fabrication of active systems, indicators, and sensors. The approaches for improving, stabilizing, and controlling the release of active compounds and highly sensitive, rapid, and reliable responsiveness, under changes in real-time are still challenging for innovative packaging development. Despite their advantages, the active and intelligent electrospun fibres for meat packaging are still restricted to research and not yet widely used for commercial products. Industrial validation of lab-scale achievements of electrospinning might boost their commercialisation. Safety must be addressed by evaluating the impact of electrospun fibres migration from package to foods on human health. This information will contribute into filling knowledge gaps and sustain clear regulations.

Influence of Fish Scale-Based Hydroxyapatite on Forcespun Polycaprolactone Fiber Scaffolds

Marine waste byproducts, especially fish scales, have proved to be one of the most prominent sources for developing sustainable materials for various applications including biomedical applications. Hydroxyapatite (HAp), being one of such biomaterials that can be synthesized from the massive fish-based waste, has received plentitude of attention due to its excellent ability to promote cell growth and proliferation. However, understanding the influence of HAp on polymer matrices that are tailored for biomedical applications is still a challenge. This study is intended to develop a sophisticated yet inexpensive method to obtain nonwoven polycaprolactone (PCL) nanofibrous scaffolds and analyze the influence of calcium-deficient nanoporous hydroxyapatite (n-HAp) on the thermal, mechanical, and biological properties of these scaffolds. The n-HAp is synthesized using two different types of fish scales, carpa (CA) and pink perch (PP), by calcination followed by nanomilling. The synthesized n-HAp powder is characterized by using X-ray diffraction, scanning electron microscopy (SEM), transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy. The PCL fibrous scaffolds were developed using a novel forcespinning technique with n-HAp as the filler. The morphology of the scaffolds was characterized using SEM and Raman spectroscopy. SEM and TEM results have confirmed the size reduction of the HAp powder after nanomilling. Thermal properties were analyzed using thermogravimetric analysis and differential scanning calorimetry. The major degradation temperature has increased by 3° and was observed to be 398° for 1 wt % filler loading for both carpa and pink perch-derived n-HAp. The increase in filler content has increased the residue left after decomposition and is 4% for 5 wt % filler loading. The crystallinity percent has increased by 7% compared to neat fibers for 1 wt % filler loading. Mechanical properties were tested using tensile tests. The tensile test strength has shown 32% improvement for 1 wt % compared to neat fibers. Cell viability tests were performed using hFOB cells which have shown significant cell growth for a high filler loading of 5 wt %. The results suggest that both CA-n-HAP and PP-n-Hap-incorporated fibrous scaffolds can be used potentially for biomedical applications after careful investigation of the scaffold behavior with longer incubation periods.

Preparation and Characterization of Polylactic Acid/Bamboo Fiber Composites

The development of green and renewable materials has attracted increasing attention in recent years. Hence, biocomposite-based packaging materials have been investigated to replace petrochemical materials in several industries, such as the food packaging and electronics packaging industries. The tensile and thermal properties of biocomposite-based packaging materials composed of polylactic acid and plant fiber were mainly investigated in the current literature, but fewer studies on the improvement of water resistance and water vapor/oxygen barrier properties of composite materials were performed. Herein, we describe a composite film comprising TBFP [a mixture of bamboo fiber powder (BFP) and silica aerogel powder] that was combined with modified polylactic acid (MPLA) in a melt-mixing process. The structure, morphology, tensile strength, thermal properties, water absorption properties, water vapor/oxygen barrier effect, cytocompatibility, and biodegradability of the composites were characterized. MPLA and TBFP improved the properties of these composites. Fourier transform infrared and X-ray diffraction spectra have shown interfacial adhesion of MPLA/TBFP, resulting in a tighter structure. Hence, the MPLA/TBFP composite had higher elongation at failure (ε), tensile strength at failure (δ), Young's modulus (E), initial decomposition temperature at 5 wt % loss (T_5%), residual yields, oxygen transmission rate, contact angles, lower thermal conductivity (k) values, water vapor transmission rate, and water absorption and biodegradability compared with PLA and PLA/BFP. It indicates that the MPLA/TBFP composites exhibited more favorable tensile strength, water resistance, and water vapor/oxygen barrier than the PLA and PLA/BFP composites. Cell growth analysis showed that the MPLA/TBFP and PLA/BFP composites own good cytocompatibility. Moreover, the biodegradability of the PLA/BFP and MPLA/TBFP composites increased with the filler (BFP or TBFP) concentration. Because of these improvements in their properties, composites can be used as packing materials in many perspectives.

Expanding Poly(lactic acid) (PLA) and Polyhydroxyalkanoates (PHAs) Applications: A Review on Modifications and Effects

The high price of petroleum, overconsumption of plastic products, recent climate change regulations, the lack of landfill spaces in addition to the ever-growing population are considered the driving forces for introducing sustainable biodegradable solutions for greener environment. Due to the harmful impact of petroleum waste plastics on human health, environment and ecosystems, societies have been moving towards the adoption of biodegradable natural based polymers whose conversion and consumption are environmentally friendly. Therefore, biodegradable biobased polymers such as poly(lactic acid) (PLA) and polyhydroxyalkanoates (PHAs) have gained a significant amount of attention in recent years. Nonetheless, some of the vital limitations to the broader use of these biopolymers are that they are less flexible and have less impact resistance when compared to petroleum-based plastics (e.g., polypropylene (PP), high-density polyethylene (HDPE) and polystyrene (PS)). Recent advances have shown that with appropriate modification methods-plasticizers and fillers, polymer blends and nanocomposites, such limitations of both polymers can be overcome. This work is meant to widen the applicability of both polymers by reviewing the available materials on these methods and their impacts with a focus on the mechanical properties. This literature investigation leads to the conclusion that both PLA and PHAs show strong candidacy in expanding their utilizations to potentially substitute petroleum-based plastics in various applications, including but not limited to, food, active packaging, surgical implants, dental, drug delivery, biomedical as well as antistatic and flame retardants applications.