Biodegradation Characteristics Research Articles

Microalgae-bacterial consortiums for enhanced degradation of nonylphenol: Biodegradability and kinetic analysis

The widespread use of non-ionic surfactant nonylphenol (NP) has led to significant water pollution, posing a threat to both ecological stability and human health. However, the efficient biodegradation method and system of NP-biodegradation remain complex scientific challenges. In this study, we isolated and characterized three Pseudomonas sp. strains SW-1 (Scenedesmus quadricauda-associated), ZL-2 (Ankistrodesmus acicularis-associated), XQ-3 (Chlorella vulgaris-associated), and one NP-degrading Cupriavidus sp. strain EB-4, which exhibited the ability to utilize NP as the sole carbon source. Furthermore, four consortiums of microalgae-bacterial, S. quadricauda and SW-1 (S-SW), A. acicularis and ZL-2 (A-ZL), C. vulgaris and XQ-3 (C-XQ), S. quadricauda and EB-4 (S-EB), were constructed to investigate their biodegradability and kinetic characteristics of NP degradation from water. The consortiums showed higher degradation efficiency compared to individual microalgae or bacteria. The C-XQ consortium exhibited the highest degradation rate, removing over 94% of NP within just seven days. The first-order model with the following order of degradation rate by consortiums was C-XQ (0.3960 d−1) > S-SW (0.3506 d−1) > A-ZL (0.1968 d−1) > S-EB (0.1776 d−1). Compared with the results of our previous study, the interaction between microalgae and bacteria is not a simple additive relationship. Our findings highlight the potential of an algal-bacterial consortium for the remediation of NP-contaminated environments.

Exploring the relationship between lignin structure and antioxidant property using lignin model compounds

Lignin has a natural polyphenol structure that is expected to replace chemically synthesized antioxidants as a native antioxidant with biodegradable and convenient source characteristics. However, the improvement of the antioxidant property of lignin and its application as an antioxidant are still somewhat limited due to the lack of understanding of the relationship between specific lignin structures and antioxidant property. Therefore, the study of the relationship between lignin structure and antioxidant property is crucial to realize the high-quality application of lignin. In this experiment, the scavenging ability of free 1,1-diphenyl-2-picrylhydrazyl (DPPH·) radicals was determined for different grades of acetylated tannins, typical lignin model compounds and different structural units of milled wood lignin to investigate the relationship between lignin structure and antioxidant property. Based on the experimental results, some structure-activity relationships were proposed and the mechanism of the antioxidant property of lignin was discussed. The number of phenolic hydroxyl groups was linearly and positively correlated with antioxidant property, and the scavenging of DPPH radicals increased significantly with the increase in the number of methoxy groups in the model compounds. Moreover, aldehyde and carboxyl groups had a negative effect on the antioxidant property of lignin, while methoxy, alkyl and alcohol hydroxyl groups played a positive role. The guaiacyl (G) and syringyl (S) units favored the antioxidant property, so the difference in the content of structural units in lignin under certain conditions of phenolic hydroxyl content also affected the antioxidant property. Therefore, the antioxidant property of aspen milled lignin was higher than that of other milled lignin from different wood species. Finally, the mechanism of DPPH free radical scavenging by lignin was revealed to better understand the relationship between lignin structure and antioxidant property.

Exploring mechanical properties of eco-friendly hybrid epoxy composites reinforced with sisal, hemp, and glass fibers

It is now widely accepted that various subsets of hybrid fiber composites reinforced with combined natural and synthetic fibers can significantly expand the applicability of composite-based materials in design and technology practice. The already existing unnatural circumstances on the planet put natural fibers far ahead of traditions in the field of materials thanks to their biodegradability characteristics, availability and over-term endurance and corrosion resistance. At the same time, composites are rapidly taking their place in many industries and sectors of the economy as metals in as much as it is economically and energetically justified. This study evaluates the mechanical properties of hybrid composites reinforced with glass, hemp, and sisal fibers. Using a hand lay-up method with epoxy resin, composite laminates were fabricated and tested for tensile, flexural, impact strengths and hardness test in accordance with ASTM standards. The experimental results revealed that glass-sisal fiber composites achieved the highest tensile strength of 69.1 MPa, while glass-hemp-sisal fiber composites exhibited superior flexural strength of 15.22 MPa and impact strength of 137.45 kJ/m2 while best hardness value was 24.73 HV for glass-sisal fibre composite. These findings underscore the potential of glass-sisal-hemp fiber-reinforced epoxy composites as viable alternatives to traditional synthetic fiber-reinforced materials in automotive industry where there are no structural loadings i.e. automobile interiors; offering enhanced mechanical performance and sustainability.

Preparation of Phosphorylated Chitosan From the Cuttlebone of Sepia pharaonis and the Effect of Concentration on Oral Clinical Pathogens.

Chitosan, a biopolymer derived from chitin, has attracted scholarly interest because of its antibacterial, biocompatible, and biodegradable characteristics. We can phosphorylate the cuttlebone of Sepia pharaonis, a natural source of chitin, to enhance its antimicrobial properties. Phosphorylated chitosan is promising for treating oral infections, which are the causative agents of a variety of dental disorders. The goalof this study is to look into how to make phosphorylated chitosan from cuttlebone and what effect different concentrations have on killing oral clinical pathogens like Streptococcus mutans, Pseudomonas aeruginosa, Escherichia coli, and Candida tropicalis. We extracted chitin and chitosan from the cuttlebone of a specimen of S. pharaonis. We then synthesized phosphorylated chitosan by phosphorylating chitosan. We then assessed the antimicrobial activities of phosphorylated chitosan using the well diffusion method. We characterized and evaluated it using Fourier transform infrared spectroscopy (FTIR), Fourier emission scanning electron microscopy (FESEM), and X-ray diffraction (XRD). Phosphorylated chitosan, in 100% concentration, had the highest inhibition zone of 14 ± 0.82 mm against P. aeruginosa and E. coli (14 ± 0.75). However, the two different concentrations studied showed no activity against both Candida tropicalis and S. mutans. This work successfully used the cuttlebone of S. pharaonis to yield phosphorylated chitosan, subsequently demonstrating its antimicrobial potential against dental clinical pathogens. Different concentrations of phosphorylated chitosan strongly controlled its antimicrobial activity, with larger concentrations exhibiting stronger inhibitory effects. According to these findings, phosphorylated chitosan appears to be a promising material for dental care solutions that target clinical bacteria in the mouth.

The feasibility of using epoxy resin reinforced with sugar cane bagasse residue for a high performance coatings: a cost of goods sold and blue ocean analysis

The natural and biodegradable characteristics of sugarcane bagasse (SCB) make it a promising ingredient for composite materials. Researchers have explored ecological and low-cost materials, identifying SCB as a green option with low pollution levels. This study investigates the strategic position for SCB and epoxy composite when applied as high-performance coatings. Epoxy resin is valued for its adhesion, strength and durability. Integrating sustainable, cost-effective reinforcements is vital for enhancing these properties and reducing environmental impact. SCB, a sugar industry waste, has favorable characteristics like fibrous structure and polymer compatibility. In this research, SCB residue was processed and incorporated into epoxy resin. Both analisys the Cost of Goods Solds (COGS) and a Blue Ocean Strategy analysis identified new market opportunities, positioning this composite as a sustainable, high-performance solution in coatings. It´s relevant to point that SCB could offer substantial improves on corrosion resistance, offering a sustainable alternative with competitive performance and cost.

Cure, mechanical and swelling characteristics of composites of neoprene rubber and starch from non-edible variety of dioscorea tuber

Composites of Polychloroprene rubber (CR, Neoprene rubber) reinforced with starch from non-edible variety of dioscorea tuber were prepared using three different vulcanizing systems. The cure, mechanical, solvent resistance and biodegradable characteristics of the composites were studied. The addition of starch from dioscorea tuber was found to improve CR’s tensile strength. The maximum torque value increases with the loading of filler and it was found to be the highest at 20 phr. The addition of starch from dioscorea tuber was found to improve CR’s tensile strength and highest value observed at 20 phr. Among the different curing systems studied, the modified DCP system shows maximum mechanical properties, optimum properties of the composites are at 20 phr. The values of the swelling coefficients were determined by examining the intake of the solvents N, N-dimethylformamide, acetonitrile, dimethyl sulfoxide and water by the composites. The soil burial test indicated that biodegradability of CR enhanced with the addition of starch. The findings of mechanical properties are supported by studies using scanning electron microscopy. Since starch is a naturally occurring biopolymer, adding it encourages microbial activity, which breaks down the composite components. This quality is essential for resolving plastic waste-related environmental issues. It is anticipated that the findings of this study will aid in the development of materials for specific product applications like gasoline hoses, tire sidewalls, seals, and so on.

Synergistic effects of starch and carrageenan from Kappaphycus alvarezii in composite film formation: Physicochemical and degradable properties

Rising concerns around plastic pollution from single-use plastic (SUPs), especially food packaging, have driven interest in sustainable alternatives. As such, algae biomass has gained attention for bioplastic production due to algae's rapid growth and abundant polysaccharides. This research focuses on extracting carrageenan from Kappaphycus alvarezii, extensively cultivated in Sabah, Malaysia, and utilizing it in combination with starch and glycerol to develop algae-based films. The physicochemical properties and degradation rate of these films were evaluated, revealing that the addition of carrageenan enhanced overall thermal stability meanwhile increasing water solubility, water content but reducing the degradation rate and swelling degree. This is primarily due to the crystalline structures of carrageenan, which provide a more rigid arrangement compared to the network of starch polymers. However, the incorporation of starch into the blends has enhanced the elongation and surface morphology, resulting in more balanced properties. Overall, these carrageenan films displayed impressive thermal, mechanical, and biodegradability characteristics, establishing their viability as substitutes for conventional plastics.

Ageing behavior of starch-based food packaging bioplastics in riparian sediments and sediment-derived dissolved organic matter in the soil environment

Riparian sediment (RS) is a translational zone separating aquatic and terrestrial ecosystems. To this date, the bioplastic's UV ageing and biodegradation features in these contaminated sediments remain unknown. It is a considerable concern to investigate whether a food packaging film can interact with RS and riparian sediment-derived Dissolved Organic Matter (RS-DOM) during biodegradation and UV ageing respectively, after disposal in a natural environmental setting. To address this research gap, for the first time, this study investigates the biodegradation and UV ageing of starch/PPst/GTR films intended for food packaging applications in RS and RS-DOM respectively. The findings revealed that RS comprises major fulvic acid DOM components. Remarkably, research demonstrates the leaching of humic acid-like DOM from the film promotes aromaticity and humification as UV ageing progresses from the third to the tenth day. Comparable DOM samples were darkly analysed, revealing aromatic proteins I and II. Furthermore, an elevated carbonyl carboxyl index confirmed significant degradation of films during UV ageing. Lesser humification, aromaticity, and higher biological activity were confirmed by a HI < 10 and BIX > 0.6 respectively. In comprehension, these findings reveal that the starch/PPst/GTR food packaging film will have a lesser adverse environmental impact after disposal, offering a hopeful outlook for the future of bioplastics.

Using gardenia pigment for ultrasonic natural dyeing of hemp fiber: A step towards sustainable dyeing

In recent years, with the country advocating the establishment of a resource-saving and environmentally friendly society, people have been pursuing a green and healthy quality of life. The non-toxic, harmless, and biodegradable characteristics of grass and wood dyeing have brought this method back to people's lives. Despite the presence of antibacterial substances such as tetrahydrocannabinol in cannabis fibers, they are still susceptible to microbial attacks. In recent years, scholars have conducted more research on the separation and purification of gardenia flower pigments, but there has been less analysis on the dyeing fibers and performance testing of gardenia flowers. The renewable characteristics, fewer side effects, and low cost increase the use of natural drugs as antibacterial agents in plant extracts or their active ingredients. This experiment used gardenia flowers as the raw material for dyeing experiments, and the dyeing percentage was used as the inspection index. Ultrasonic dyeing was carried out on hemp fibers after degumming treatment. It also aims to endow these dyed fabrics with natural antibacterial properties. During the sorting process, a liquid bath ratio of 1:20 was selected and experiments were conducted under different parameter variations. During the dyeing process, potassium aluminum sulfate (alum) is used as a mordant, and ultrasound is used as an auxiliary dyeing method. After dyeing, evaluate the fibers based on the percentage of exhaustion of obtained fiber and antibacterial activity against Staphylococcus aureus and Escherichia coli. At the same time, the FT-IR analysis, strength, and color fastness of the sorted samples were also checked. Single factor experiments were conducted by controlling the ultrasonic frequency, dyeing temperature, time, and mordant concentration to analyze the effect of gardenia pigment on the dyeing percentage. Response surface design experiments were used to optimize the dyeing process parameters. The research results indicate that the optimal process conditions for dyeing gardenia flowers are ultrasonic power of 85 %, dyeing temperature of 77 ℃, dyeing time of 60 min, and mordant concentration of 15 g/L. The main and secondary order of factors affecting the dyeing effect of hemp fibers is: mordant concentration>ultrasonic power>dyeing temperature. After optimal dyeing process, the hemp fiber shows a bright yellow color with a dyeing percentage of 57.32 %. The single fiber strength is not affected, and the color fastness to water washing and sun exposure meets the requirements for consumption. The infrared spectrum shows good dyeing effect. It has a certain antibacterial effect on Staphylococcus aureus, but the antibacterial effect on Escherichia coli is not significant. Due to these processes, it has been determined that hemp fiber can obtain antibacterial activity through the use of gardenia flowers and can be effectively colored.

A Brief Review on the Emerging Role of Bacterial Pigments: From Industrial Uses to Novel Therapeutic Applications

Pigments produced by microorganisms are in high demand due to their safe, non-toxic, and biodegradable characteristics in both industrial and pharmaceutical fields. Using bacteria for pigment production offers several advantages, such as a short life cycle and ease of genetic modification. Numerous studies have highlighted that soil bacteria significantly contribute to the production of coloured pigments as secondary metabolites. Bacterial pigments are well-known for their antimicrobial, antioxidant, and anticancer properties, offering new therapeutic opportunities for the development of novel drugs. However, compared to fungal pigments, most bacterial pigments are still in the research and development stage. Hence, efforts to intensify bacterial pigment production are essential to make them readily available on the market at a low cost for various applications. This review article sheds light on bacterial pigments and their various applications based on the data available in the literature.

Experimental Study on Tribological, Rheological and Bio-degradability Characteristics of Canola Oil with TiO2 Nanoparticles as Bio-nanolubricants

In response to growing environmental concerns about the adverse effects of conventional lubricants, there has been a surge in the demand for eco-friendly alternatives. Biodegradable lubricants, crafted from renewable sources, represent a sustainable solution to address these environmental apprehensions. This research describes the tribological, rheological properties and biodegradability of rapeseed oil with 0.25 to 1.25 weight percent TiO2 nanoparticles as additives. The lubricant samples were prepared using a magnetic stirrer and an ultrasonic device. Friction and wear properties such as coefficient of friction and wear scar diameter were determined using a four-ball tester. In comparison with SAE20W40, samples 1 (0.25 weight percentage of TiO2) and sample 2 (0.5 weight percentage of TiO2) shown remarkably improved tribological performance, with 73.32% and 66.76% decreases in coefficient of friction (COF), respectively. Shear stress, shear rate and dynamic viscosity are analyzed using a rheometer. The acquired results are juxtaposed with both pure canola oil and various mineral oils for comparison. The nano-lubricant synthesized in this study emerges as a viable alternative to SAE10, DXT3 (steering fluid), and SAE20W50 grade oils, demonstrating lower friction and a reduced wear scar diameter. Biodegradability tests were performed on all generated samples using the Biochemical Oxygen Demand (BOD) apparatus, and all samples exhibited a BOD to Chemical Oxygen Demand (COD) ratio better than 0.5, indicating biocompatibility. The findings of the research investigation indicate that the combination of canola oil with TiO2 blends holds significant promise as an alternative to conventional synthetic lubricant oils.

Bright green cellulose-based fluorescent probe toward Au3+ smartphone technology recognition and its visualization application

In this study, a novel fluorescent probe, MAC-2, for the detection of Au3+ was designed and synthesised using cellulose as a carrier combined with benzothiazole derivatives. The structure of the probe was confirmed by SEM, XRD, FTIR, and 1H NMR, also the optical properties of the product were investigated. MAC-2 showed bright green fluorescence under a 365 nm UV lamp and exhibited significant quenching behaviour toward Au3+. MAC-2 utilises more sustainable biomass resources, featuring green and biodegradable characteristics that meet environmental requirements. Compared with most reported probes, it exhibits notable fluorescence properties. The limit of detection (LOD) is as low as 0.057 μM, and the response time is 1 min. It also demonstrates good specific recognition and anti-interference abilities. In addition, a smartphone was used as a portable signal processing device to achieve rapid detection of Au3+ concentration. Meanwhile, MAC-2 was successfully prepared as a fluorescent test strip, providing a potential application for the convenient detection of Au3+. The high sensitivity and selectivity exhibited by cellulose-based fluorescent probes in detecting Au3+ offer valuable insights and new ideas for the detection of other metal ions and biomolecules. These inspirations will help promote the continuous development of research and applications in related fields.

Exploratory Investigation of Zinc-Modified Borosilicate Bioactive Glass: A New Methodology for Its Biocompatibility, Immunoregulation, and Pro-Angiogenic Property Evaluation.

The assessment of biodegradable materials, such as bioactive glass, under the existing ISO 10993 standard test methods poses a significant challenge due to potential cell viability impairment caused by the accumulation of degraded products in a static environment. Therefore, innovative methodologies are urgently needed to tailor the unique biodegradation characteristics of these materials, providing more precise and scientific insights into biosafety and efficacy verification. Motivation by its bidirectional regulation of angiogenesis and immunity, zinc (Zn) was incorporated into sol-gel-derived borosilicate bioactive glasses (SBSGs) to fabricate Zn-incorporated borosilicate bioactive glasses (SBSG-Zn) to complement the tissue repair capabilities of bioactive glasses. Both SBSG and SBSG-Zn glasses consist of nanosized particles, slit mesoporous pores, high specific surface areas, and bioreactivity. In vitro comparative analysis, conducted according to ISO 10993 standards, demonstrates that only at suitable dilution rates─such as the 8-fold dilution employed in this study─do extracts of SBSG and SBSG-Zn glasses exhibit low cytotoxicity when cultured with human umbilical vein endothelial cells (HUVECs). Notably, SBSG-Zn glasses show optimal promotion of angiogenic gene expression in HUVECs. Furthermore, within an appropriate concentration range of released ions, SBSG-Zn glass extracts not only promote cell survival but also modulate the expression of anti-inflammatory genes while simultaneously inhibiting pro-inflammatory genes concurrently. After being implanted in rat subcutaneous defect models, both SBSG and SBSG-Zn glasses demonstrated the local immunoregulation and angiogenic effects. SBSG-Zn stands out by demonstrating superior modulation of M1/M2 polarization in macrophages as validated by altered secretion of key factors in macrophages and expression of relevant growth factors in HUVECs. These findings underscore the potential for convenient manipulation of localized angiogenic and immunoregulation through the incorporation of zinc into bioactive glass, emphasizing the importance of ensuring the appropriate ion doses are applied for achieving optimal therapeutic efficiency.

Eggshell bio‐filler integration in jute/banana fiber‐reinforced epoxy hybrid composites: Fabrication and characterization

AbstractThe use of waste‐based bio‐fillers in composite manufacturing has increased in recent years due to their sustainable and biodegradable characteristics. The current study fabricates jute/banana (JB) fiber‐reinforced epoxy composites incorporating waste‐derived eggshell (ES) bio‐filler and investigates the effect of ES bio‐filler on the mechanical, morphological, and water absorption properties of the composites. JB fibers (1:1) and varying ES filler contents (5, 10, 15, and 20 wt%) were used to manufacture the composites using the hand lay‐up technique. Their tensile, flexural, and impact properties, microstructure, chemical compositions, and water absorption are then examined. It is found that the composite composed of 15 wt% ES exhibits better tensile and flexural properties with a tensile modulus and strength of 4.42 GPa and 95.27 MPa, and a flexural modulus and strength of 3.96 GPa and 117.47 MPa, respectively, whereas the composite filled with 5 wt% ES shows a maximum impact strength of 46.83 kJ/m2 and drops with increasing bio‐fillers. Scanning electron microscopy reveals that composite failures occur due to jute and banana fiber fractures, filler–fiber‐matrix debonding, fiber pullout, and ES filler agglomeration. Moreover, water absorption reduces as the ES content rises, and the 20 wt% ES filler‐based composite shows a minimum water absorption of 7.67% after 240 h. This study provides some insights to promote the usage of ES bio‐filler in natural fiber composites to improve their mechanical and water absorption properties and their potential applications in the internal structures of automobiles, aircraft, and construction.

Awareness Regarding Clear Aligner Disposal Among Orthodontists and General Dentists: A Cross-sectional Survey-based Study

Aim and Objective: To assess the awareness of clear aligner disposal among orthodontists and general dentists. Materials and Methods: A cross-sectional electronic survey (e-survey) was developed based on the use of Google Forms. The survey link was randomly disseminated across social media platforms consisting of orthodontists and general dentists. The responses were subsequently tabulated and analyzed using statistical analysis with the help of Statistical Product and Services Solution software version 23.0. The survey comprised questions consisting of demographics, frequency of usage of clear aligners, and awareness on disposal of clear aligners. Results: The survey gathered responses from 760 participants, including 374 orthodontists and 384 general dentists from the 1,000 dentists and orthodontists who were surveyed, revealing trends in clear aligner usage, disposal practices, and awareness. Orthodontists showed higher frequency and safer disposal practices. A knowledge gap exists among dental practitioners regarding biodegradation characteristics and disposal regulations. Both groups express a shared interest in environmentally responsible practices, emphasizing the necessity for education and comprehensive guidelines from aligner companies to mitigate environmental impact. Conclusion: Clear aligners are popular in orthodontic treatment which contributes to environmental concerns due to improper disposal. The study explored clear aligner disposal practices among general dentists and orthodontists. The study underscores the need for increased awareness among orthodontists and general dentists, emphasizing proper clear aligner disposal methods and the importance of comprehensive instructions from aligner companies.

Synthesis of hemostatic aerogel of TEMPO-oxidized cellulose nanofibers/collagen/chitosan and in vivo/vitro evaluation

The treatment of internal hemorrhage remains challenging due to the current limited antibacterial capability, hemostatic efficacy, and biocompatibility of hemostatic materials. The TEMPO-oxidized cellulose nanofibers/collagen/chitosan (TCNF/COL/CS) hemostatic aerogel was developed in this work by physically encasing COL in a sandwich structure and electrostatically self-assembling polyanionic TCNF with polycationic CS. In vitro coagulation experiments revealed the favorable procoagulant properties of TCNF/COL/CS along with high adhesion to erythrocytes and platelets. TCNF/COL/CS significantly increased the hemostatic efficacy by 59.8 % and decreased blood loss by 62.2 % in the liver injury model when compared to Surgicel®, the most frequently used hemostatic material. Furthermore, it demonstrated outstanding biodegradability both in vitro and in vivo, and a substantial increase in resistance (96.8 % against E. coli and 95.4 % against S. aureus) compared to TCNF. The significant hemostatic and biodegradable characteristics of TCNF/COL/CS can be ascribed to its interconnected porous structure, increased porosity, and efficient water absorption, along with the synergistic effect of the three constituents. The TCNF/COL/CS aerogel shows significant potential to control internal bleeding. A novel plant-derived nanocellulose composite aerogel has been described here for the first time; it has outstanding antibacterial characteristics, higher biocompatibility, and outstanding hemostatic characteristics in vivo.

Fibrin-konjac glucomannan-black phosphorus hydrogel scaffolds loaded with nasal ectodermal mesenchymal stem cells accelerated alveolar bone regeneration

BackgroundEffective treatments for the alveolar bone defect remain a major concern in dental therapy. The objectives of this study were to develop a fibrin and konjac glucomannan (KGM) composite hydrogel as scaffolds for the osteogenesis of nasal mucosa-derived ectodermal mesenchymal stem cells (EMSCs) for the regeneration of alveolar bone defect, and to investigate the osteogenesis-accelerating effects of black phosphorus nanoparticles (BPNs) embedded in the hydrogels.MethodsPrimary EMSCs were isolated from rat nasal mucosa and used for the alveolar bone recovery. Fibrin and KGM were prepared in different ratios for osteomimetic hydrogel scaffolds, and the optimal ratio was determined by mechanical properties and biocompatibility analysis. Then, the optimal hydrogels were integrated with BPNs to obtain BPNs/fibrin-KGM hydrogels, and the effects on osteogenic EMSCs in vitro were evaluated. To explore the osteogenesis-enhancing effects of hydrogels in vivo, the BPNs/fibrin-KGM scaffolds combined with EMSCs were implanted to a rat model of alveolar bone defect. Micro-computed tomography (CT), histological examination, real-time quantitative polymerase chain reaction (RT-qPCR) and western blot were conducted to evaluate the bone morphology and expression of osteogenesis-related genes of the bone regeneration.ResultsThe addition of KGM improved the mechanical properties and biodegradation characteristics of the fibrin hydrogels. In vitro, the BPNs-containing compound hydrogel was proved to be biocompatible and capable of enhancing the osteogenesis of EMSCs by upregulating the mineralization and the activity of alkaline phosphatase. In vivo, the micro-CT analysis and histological evaluation demonstrated that rats implanted EMSCs-BPNs/fibrin-KGM hydrogels exhibited the best bone reconstruction. And compared to the model group, the expression of osteogenesis genes including osteopontin (Opn, p < 0.0001), osteocalcin (Ocn, p < 0.0001), type collagen (Col , p < 0.0001), bone morphogenetic protein-2 (Bmp2, p < 0.0001), Smad1 (p = 0.0006), and runt-related transcription factor 2 (Runx2, p < 0.0001) were all significantly upregulated.ConclusionsEMSCs/BPNs-containing fibrin-KGM hydrogels accelerated the recovery of the alveolar bone defect in rats by effectively up-regulating the expression of osteogenesis-related genes, promoting the formation and mineralisation of bone matrix.

Chitosan-casein blended with condensed tannin and carnauba wax for the fabrication of antibacterial and antioxidant food packing films

In this study, various chitosan-based films such as chitosan (C), chitosan-condensed tannin (CT), chitosan-casein (CC), and chitosan-casein-condensed tannin (CCT) films were prepared for the purpose of food packaging. In order to improve the hydrophobicity of these films, carnauba wax was blended into CCT to produce CCTW film. Properties such as morphology, UV resistance, water solubility, barrier performance, tensile strength, antioxidant, antibacterial and its performance as food packaging were evaluated. Compared with other chitosan-based films, CCTW films exhibited higher UV resistance, tensile strength, thermal stability and hydrophobicity. The addition of both condensed tannin and carnauba wax has significantly decreased the water vapor and oxygen permeability of the CCTW films. The CCTW films were proved capable of repelling most daily consuming liquids. Besides, CCTW films displayed outstanding free radical scavenging rate and antibacterial properties. Meanwhile, bananas wrapped with CCTW films remained fresh for seven days without any mold growth and outperformed other types of films. Apart from that, the CCTW films also showed biodegradable characteristics after exposure to Penicillium sp. These distinguished characteristics made the CCTW films a promising packaging material for long-term food storage.

Active Food Packaging from Alginate-Based Film Containing Onion Peel Extract (Allium cepa)

Consumers wanting safe and eco-friendly food packaging have led to better active packaging materials. Alginate is a polysaccharide extracted from seaweed and has the potential to be considered a promising material for packaging applications; however, its application is limited due to poor mechanical properties and high water vapor (WVP). The mechanical and barrier properties can be altered by adding or blending with other materials, such as the incorporation of bioactive compounds from onion peel extract (Allium Cepa). This study was designed to extract onion peel and test its antioxidant and antimicrobial activities; alginate-based film incorporated different concentrations of onion peel extract (12.5%, 25%, and 50%) (w/v) and determined its antioxidant or antimicrobial activity and physicochemical properties. Results demonstrated that the onion peel extract and alginate-based films containing onion peel extract show antioxidant activity; however, no antimicrobial activity was detected. When the concentration of onion peel extract (Allium Cepa) in alginate-based film increased, it significantly improved the alginate-based film's mechanical properties, colour, solubility, and biodegradability. However, the water vapour permeability was reduced by increasing the onion peel extract. In conclusion, adding onion peel extract improved the antioxidant activity, colour, mechanical strength, solubility, and biodegradability characteristics of alginate-based films compared to control. Hence, this film has the potential to be used as active packaging.

The effect of Silver addition and deformation parameters on mechanostructure, biodegradation, antimicrobial and mechanical properties of Zn-based biodegradable alloys.

Although low mechanical properties, Zinc (Zn) alloy systems with Copper (Cu) and Silver (Ag) as alloying elements have strong biocompatibility and biodegradability characteristics. This study examined the effects of rolling parameters and Ag alloying on the mechanical, biodegradable, and final structure of an alloy based on Zn. Comparing treated and untreated specimens, the addition of Ag led to a considerable improvement in both hardness and compressive strength. The produced alloys with varying amounts of Ag (between 1 and 4wt%) were cold rolled at 400-800r/min and friction coefficients between 0.3 and 0.5. The alloys' ultimate strength rose with an increase in rolling speed for Zn1Cu4Ag, and hardness and compressive strengths rose to 80HV and 470MPa, respectively. It was demonstrated that rolling force rose somewhat with Ag concentration but significantly increased with rolling speed and friction. E. Coli and S. aureus were used to assess the biodegradable alloys' antibacterial properties. For the Zn-1Cu-2Ag alloy, the inclusion of Ag resulted in a considerable (50%) rise in antibacterial activity that exceeded the effects seen in other alloy systems.