Large amounts of spent coffee grounds (SCGs) are often discarded and there is a need to find alternative disposal methods due to environmental concerns. This project aims to develop sustainable ...materials by re-purposing spent coffee grounds (SCGs). Oil extraction was performed using different organic solvents and yielded approximately 10% coffee oil. Coffee oil contains potentially useful chemical compounds such as fatty acids and caffeine. They also exhibited antioxidant properties. Extracted SCGs (ESCGs) were blended with epoxy resin to form composites. ESCG composites displayed a general decrease in mechanical properties relative to epoxy. However, improvements were observed when comparing ESCG composites and SCG composites. The greatest improvement belongs to epoxy composite filled with acetone-ESCGs, where the tensile strength, flexural modulus and flexural strength increased to 23.4 MPa, 3.02 GPa and 42.9 MPa respectively. This study presents a way to exploit waste materials which contributes to the goal of sustainability.
Spent coffee grounds are mostly discarded as waste. Here we recycle them for chemical compounds and as composite material fillers. Our study evaluated the chemical composition of coffee oil extracts and mechanical properties of composites formed.
Viral epidemics develop from the emergence of new variants of infectious viruses. The lack of effective antiviral treatments for the new viral infections coupled with rapid community spread of the ...infection often result in major human and financial loss. Viral transmissions can occur via close human‐to‐human contact or via contacting a contaminated surface. Thus, careful disinfection or sanitization is essential to curtail viral spread. A myriad of disinfectants/sanitizing agents/biocidal agents are available that can inactivate viruses, but their effectiveness is dependent upon many factors such as concentration of agent, reaction time, temperature, and organic load. In this work, we review common commercially available disinfectants agents available on the market and evaluate their effectiveness under various application conditions. In addition, this work also seeks to debunk common myths about viral inactivation and highlight new exciting advances in the development of potential sanitizing agents.
Virus pandemics are recurrent in human history, and one of the major means of human‐to‐human viral transmissions occur through contact with contaminated surfaces. Herein, the authors provide a summary of the major commercially available sanitizing agents used to inactivate viruses and critically evaluate their effectiveness to do so.
Solvents are essential for chemical synthesis and material preparation; however, traditional solvents face challenges in meeting safety and sustainability standards. Consequently, there is a growing ...focus on environmentally friendly solvent systems for polymeric materials, with deep eutectic solvents (DESs) standing out as promising alternatives owing to their eco-friendly attributes. In this review, we summarize studies on this novel solvent system in a broad range of applications, where DESs play multiple roles in polymer synthesis and corresponding material fabrication. In detail, we focus on the utilization of DESs in the synthesis of green polymers and related functional polymeric materials ranging from soft materials such as gels and nanofibers to membranes, films, and complex architectures generated from various techniques such as 3D printing, electrospinning, and self-assembly, together with their properties. Moreover, we discuss the green credentials through sustainability analysis and life-cycle assessment of DES-based polymeric materials. We believe this review will inspire more investigation into the use of DESs for functional green polymeric materials towards a sustainable future.
Presently, the rapid depletion of resources and drastic climate change highlight the importance of sustainable development. In this case, nanochitin derived from chitin, the second most abundant ...renewable polymer in the world, possesses numerous advantages, including toughness, easy processability and biodegradability. Furthermore, it exhibits better dispersibility in various solvents and higher reactivity than chitin owing to its increased surface area to volume ratio. Additionally, it is the only natural polysaccharide that contains nitrogen. Therefore, it is valuable to further develop this innovative technology. This review summarizes the recent developments in nanochitin and specifically identifies sustainable strategies for its preparation. Additionally, the different biomass sources that can be exploited for the extraction of nanochitin are highlighted. More importantly, the life cycle assessment of nanochitin preparation is discussed, followed by its applications in advanced manufacturing and perspectives on the valorization of chitin waste.
Among the numerous strategies to synthesize nanochitin from waste, the more sustainable methods are identified to facilitate the valorization of chitin waste and its eventual infiltration in advanced manufacturing.
Osteoarthritis (OA) is common musculoskeletal disorders associated with overgeneration of free radicals, and it causes joint pain, inflammation, and cartilage degradation. Lignin as a natural ...antioxidant biopolymer has shown its great potential for biomedical applications. In this work, we developed a series of lignin-based nanofibers as antioxidative scaffolds for cartilage tissue engineering. The nanofibers were engineered by grafting poly(lactic acid) (PLA) into lignin via ring-opening polymerization and followed by electrospinning. Varying the lignin content in the system was able to adjust the physiochemical properties of the resulting nanofibers, including fiber diameters, mechanical and viscoelastic properties, and antioxidant activity. In vitro study demonstrated that the PLA-lignin nanofibers could protect bone marrow-derived mesenchymal stem/stromal cells (BMSCs) from oxidative stress and promote the chondrogenic differentiation. Moreover, the animal study showed that the lignin nanofibers could promote cartilage regeneration and repair cartilage defects within 6 weeks of implantation. Our study indicated that lignin-based nanofibers could serve as an antioxidant tissue engineering scaffold and facilitate the cartilage regrowth for OA treatment.
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•ROS-responsive nanocomposite nanofibers were fabricated by using PCL, PEGDA-EDT and rGO, as stimuli-responsive drug delivery system.•The ROS-responsive nanocomposite nanofibers ...enabled high loading of puerarin, and facilitate efficient controlled release based on ROS condition in the OA microenvironment.•The PPE@rGO-Pue nanofibers exhibited favourable anti-inflammatory and antioxidative properties for chonro-protection.•The PPE@rGO-Pue nanofibers enable to downregulating the expression of IL-1β and MMP13, therefore limiting the cartilage degradation in OA model.
Reactive Oxygen Species (ROS) plays an important role in osteoarthritis (OA) development and progression. Here, a ROS-responsive nanocomposite scaffold called PPE@rGO-Pue was fabricated by electrospinning, wherein PCL served as the backbone, PEGDA-EDT as the ROS responsive motif, and rGO as puerarin (Pue) carrier. The electrospun nanofibers composed of PEGDA-EDT and rGO exhibits accelerated Pue release behavior in the response to H2O2 through dose-dependent manner in 2 weeks. The interactions of PEGDA-EDT and Pue dramatically inhibits ROS production and activates antioxidant enzymes such as CAT, GSS, SOD, and GSH. Furthermore, the expression of inflammatory factor IL-1β had decrease significantly. Subsequently, PPE@rGO-Pue had shown chondro-protective effect for OA, which was evidenced by the suppression of MMPs, resulting in matrix degradation and the increase of Col2a1 and GAG that attenuated the cartilage erosion. In summary, this ROS-responsive electrospun nanofibers with sustained release of Pue exhibited antioxidative, anti-inflammatory, and chondro-protective potentials, suggesting that it could be an excellent drug carrier for OA therapy. This work may shed light on the design of antioxidative biomaterials for OA.
In this study, a fast and simple dissolution and coagulation method was adopted to produce polyethylenimine (PEI)-incorporated chitosan beads. The beads were characterized using FESEM, BET, TGA, and ...FTIR analysis. Evaluation of adsorption isotherms, adsorption kinetics, and thermodynamics support that the beads exhibit chemisorption, which process is spontaneous at low temperatures. The presence of 30% PEI content enhanced the adsorption capacity of chitosan beads by about two-fold, achieving a maximum of 183.15 mg/g as calculated from the Langmuir adsorption isotherm. Finally, the PEI-incorporated beads exhibited good regeneration and can maintain 94% performance across up to eight cycles which is a promising reusable dyes absorbent material to tackle water pollution on our environment.
Klebsiella pneumoniae (Kp) infection is an important healthcare concern. The ST258 classical (c)Kp strain is dominant in hospital-acquired infections in North America and Europe, while ST23 ...hypervirulent (hv)Kp prevails in community-acquired infections in Asia. This study aimed to develop symptomatic mucosal infection models in mice that mirror natural infections in humans to gain a deeper understanding of Kp mucosal pathogenesis. We showed that cKp replicates in the nasal cavity instead of the lungs, and this early infection event is crucial for the establishment of chronic colonization in the cecum and colon. In contrast, hvKp replicates directly in the lungs to lethal bacterial load, and early infection of esophagus supported downstream transient colonization in the ileum and cecum. Here, we have developed an in vivo model that illuminates how differences in Kp tropism are responsible for virulence and disease phenotype in cKp and hvKp, providing the basis for further mechanistic study.
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•Classical Klebsiella pneumoniae (cKp) induces diffused lung inflammation•Hypervirulent Klebsiella pneumoniae (hvKp) induces necrotic lung inflammation•Early nasal infection is essential for cKp to establish chronic colonization of the gut•hvKp airway infection led to high but transient bacterial load in the ileum
Medical microbiology
Traditional optical waveguides or mediums are often silica-based materials, but their applications in biomedicine and healthcare are limited due to the poor biocompatibility and unsuitable mechanical ...properties. In term of the applications in human body, a biocompatible hydrogel system with excellent optical transparency and mechanical flexibility could be beneficial. In this review, we explore the different designs of hydrogel-based optical waveguides derived from natural and synthetic sources. We highlighted key developments such as light emitting contact lenses, implantable optical fibres, biosensing systems, luminating and fluorescent materials. Finally, we expand further on the challenges and perspectives for hydrogel waveguides to achieve clinical applications.
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•Design requirements, optimization, and properties of implantable waveguides are summarized.•Precursor polymers for hydrogel fabrication and design are discussed.•Current applications of transparent light delivery hydrogels are explored.•Challenges and outlook of hydrogel-based waveguides in biomedical applications are discussed.
The expansion of the textile industry and improvements in living standards have led to increased cotton textile production, resulting in a rise in textile waste, with cotton accounting for 24% of ...total textile waste. Effective waste management through recycling and reuse is crucial to reducing global waste production. Nanocellulose has diverse applications in environmental, geotechnical, food packaging, and biomedical engineering areas. As interest in nanocellulose's unique properties grows, cotton-based textile waste emerges as a promising source for nanocellulose development. However, there is a notable lack of comprehensive reviews on the extraction of nanocellulose from textile waste as a sustainable biomaterial. This paper aims to address this gap by exploring current extraction processes, properties, and recent applications of nanocellulose derived from textile waste. We discussed (1) the potential of nanocellulose resources from different textile wastes, (2) a comparison of the various extraction methods, (3) the functionalization technology and the potential application of such nanocellulose in the textile industry, and (4) the life cycle assessment (LCA) and potential gap of the current technology. It also emphasizes the potential reintegration of extracted nanocellulose into the textile industry to manufacture high-value products, thus completing the loop and strengthening the circular economy.
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