Biodegradable Polyester Nanoparticle Vaccines Deliver Self-Amplifying mRNA in Mice at Low Doses

Delivery of self-amplifying mRNA (SAM) has high potential for infectious disease vaccination due to its self-adjuvanting and dose-sparing properties. Yet a challenge is the susceptibility of SAM to degradation and the need for SAM to reach the cytosol fully intact to enable self-amplification. Lipid nanoparticles are successfully deployed at incredible speed for mRNA vaccination, but aspects such as cold storage, manufacturing, efficiency of delivery, and the therapeutic window can benefit from further improvement. To investigate alternatives to lipid nanoparticles, a class of >200 biodegradable end-capped lipophilic poly(beta-amino ester)s (PBAEs) that enable efficient delivery of SAM in vitro and in vivo as assessed by measuring expression of SAM encoding reporter proteins is developed. The ability of these polymers to deliver SAM intramuscularly in mice is evaluated, and a polymer-based formulation that yields up to 37-fold higher intramuscular (IM) expression of SAM compared to injected naked SAM is identified. Using the same nanoparticle formulation to deliver a SAM encoding rabies virus glycoprotein, the vaccine elicits superior immunogenicity compared to naked SAM delivery, leading to seroconversion in mice at low RNA injection doses. These biodegradable nanomaterials may be useful in the development of next-generation RNA vaccines for infectious diseases.Copyright © 2023 The Authors. Advanced Therapeutics published by Wiley-VCH GmbH.

Eco-Friendly Hierarchical Nanoporous Microfiber Respirator Filters Fabricated Using Rotary Jet Spinning Technology (RJS)

The current global health crisis caused by the SARS-CoV-2 virus (COVID-19) has increased the use of personal protective equipment, especially face masks, leading to the disposal of a large amount of plastic waste causing an environmental crisis due to the use of non-biodegradable and non-recyclable polymers, such as polypropylene and polyester. In this work, an eco-friendly biopolymer, polylactic acid (PLA), was used to manufacture hierarchical nanoporous microfiber biofilters via a single-step rotary jet spinning (RJS) technique. The process parameters that aid the formation of nanoporosity within the microfibers were discussed. The microstructure of the fibers was analyzed by scanning electron microscopy (SEM) and a noninvasive X-ray microtomography (XRM) technique was employed to study the three-dimensional (3D) morphology and the porous architecture. Particulate matter (PM) and aerosol filtration efficiency were tested by OSHA standards with a broad range (10-1000 nm) of aerosolized saline droplets. The viral penetration efficiency was tested using the phi X174 bacteriophage (similar to 25 nm) with an envelope, mimicking the spike protein structure of SARS-CoV-2. Although these fibers have a similar size used in N95 filters, the developed biofilters present superior filtration efficiency (similar to 99%) while retaining better breathability (<4% pressure drop) than N95 respirator filters.

Key Design Features of Lipid Nanoparticles and Electrostatic Charge-Based Lipid Nanoparticle Targeting.

Lipid nanoparticles (LNP) have gained much attention after the approval of mRNA COVID-19 vaccines. The considerable number of currently ongoing clinical studies are testament to this fact. These efforts towards the development of LNPs warrant an insight into the fundamental developmental aspects of such systems. In this review, we discuss the key design aspects that confer efficacy to a LNP delivery system, i.e., potency, biodegradability, and immunogenicity. We also cover the underlying considerations regarding the route of administration and targeting of LNPs to hepatic and non-hepatic targets. Furthermore, since LNP efficacy is also a function of drug/nucleic acid release within endosomes, we take a holistic view of charged-based targeting approaches of LNPs not only in the context of endosomal escape but also in relation to other comparable target cell internalization strategies. Electrostatic charge-based interactions have been used in the past as a potential strategy to enhance the drug release from pH-sensitive liposomes. In this review, we cover such strategies around endosomal escape and cell internalization in low pH tumor micro-environments.

Super effective antimicrobial silver-sputtered coatings on poly(lactic acid) against bacteria and omicron SARS-CoV-2

Poly(lactic acid) (PLA) is a biopolymer with properties potentially suitable for fabricating packaging, medical devices, and healthcare products in a more friendly environmental way because this polymer presents biodegradability, compostability, low carbon footprint, and recyclability. However, PLA does not present intrinsic antimicrobial properties. Antimicrobial materials are highly desirable for manufacturing smart packaging and personal protective equipment to secure food and health professionals against pathogenic microorganisms. In this work, we evaluated the antimicrobial performance of (Ag)-coated PLA against Escherichia coli, Bacillus subtilis, and Omicron severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). PLA was rapidly coated with metallic Ag by pulsed direct current magnetron sputtering (pDCMS) for 5, 10, and 20 s. Atomic force microscopy indicates that the Ag coating grows predominantly on the PLA surface via a bulk diffusion mechanism. According to bactericidal and quantitative reverse transcription polymerase chain reaction assays, Ag-coated PLA was capable of inhibiting bacterial biofilm formation and disrupting the genetic material of the Omicron SARS-CoV-2. X-ray high-resolution photoelectron and nuclear magnetic resonance results suggest no polymer chain scission in the PLA bulk due to plasma thermal stress effects during Ag sputtering. © 2023 Elsevier Ltd

Development of Polymeric Binder from Expanded Polystyrene (EPS) Foam Waste as Construction Materials

Expanded Polystyrene (EPS) foam wastes become a huge environmental issue as most of them are non-biodegradable materials and are disposed of inappropriately. It was reported that the amount of plastic and foam wastes for food containers and other packagings was evidently increased during the past 5 years, especially since the COVID19 pandemic. This work studied the development of the polymeric foam binder from the EPS foam waste for the production of green construction blocks or pavement tiles. The types of solvent (acetone and toluene) and the amount of additional EPS foam binder were investigated. The results show that the appropriate mixtures contained EPS foam binder from 15% to 30% to achieve maximum compressive strength at approximately 10 to 12 MPa with the optimal unit weight of 1,600 to 1,900 kg/m3. Those outcomes have equally passed the strength class of Thai Industrial Standard (TIS 57 and 77) for construction brick and block. This eco-friendly technique could facilitate value-added production and reduce the environmental impact of EPS wastes disposal. Moreover, it is one of the alternative approaches to promote greener and cleaner production for environmentally friendly construction materials.

The face behind the Covid-19 mask - A comprehensive review.

The threat of epidemic outbreaks like SARS-CoV-2 is growing owing to the exponential growth of the global population and the continual increase in human mobility. Personal protection against viral infections was enforced using ambient air filters, face masks, and other respiratory protective equipment. Available facemasks feature considerable variation in efficacy, materials usage and characteristic properties. Despite their widespread use and importance, face masks pose major potential threats due to the uncontrolled manufacture and disposal techniques. Improper solid waste management enables viral propagation and increases the volume of associated biomedical waste at an alarming rate. Polymers used in single-use face masks include a spectrum of chemical constituents: plasticisers and flame retardants leading to health-related issues over time. Despite ample research in this field, the efficacy of personal protective equipment and its impact post-disposal is yet to be explored satisfactorily. The following review assimilates information on the different forms of personal protective equipment currently in use. Proper waste management techniques pertaining to such special wastes have also been discussed. The study features a holistic overview of innovations made in face masks and their corresponding impact on human health and environment. Strategies with SDG3 and SDG12, outlining safe and proper disposal of solid waste, have also been discussed. Furthermore, employing the CFD paradigm, a 3D model of a face mask was created based on fluid flow during breathing techniques. Lastly, the review concludes with possible future advancements and promising research avenues in personal protective equipment.

Microplastics in the Ecosystem: An Overview on Detection, Removal, Toxicity Assessment, and Control Release

In recent decades, the accumulation and fragmentation of plastics on the surface of the planet have caused several long-term climatic and health risks. Plastic materials, specifically microplastics (MPs;sizes < 5 mm), have gained significant interest in the global scientific fraternity due to their bioaccumulation, non-biodegradability, and ecotoxicological effects on living organisms. This study explains how microplastics are generated, transported, and disposed of in the environment based on their sources and physicochemical properties. Additionally, the study also examines the impact of COVID-19 on global plastic waste production. The physical and chemical techniques such as SEM-EDX, PLM, FTIR, Raman, TG-DSC, and GC-MS that are employed for the quantification and identification of MPs are discussed. This paper provides insight into conventional and advanced methods applied for microplastic removal from aquatic systems. The finding of this review helps to gain a deeper understanding of research on the toxicity of microplastics on humans, aquatic organisms, and soil ecosystems. Further, the efforts and measures that have been enforced globally to combat MP waste have been highlighted and need to be explored to reduce its potential risk in the future. © 2022 by the authors.

Biobased polymer SF/PHBV composite nanofiber membranes as filtration and protection materials

With the emergence of the COVID-19, masks and protective clothing have been used in huge quantities. A large number of non-degradable materials have severely damaged the ecological environment. Now, people are increasingly pursuing the use of environmentally friendly materials to replace traditional chemical materials. Silk fibroin (SF) and Poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) have received increasing attention because of their unique biodegradability and biocompatibility. In this paper, a series of biodegradable SF/PHBV nanofiber membranes with different PHBV content were fabricated by using electrospinning technology. The morphology of the electrospun SF/PHBV composite nanofiber was observed by scanning electron microscopy (SEM). The average diameters of the pure SF, SF/PHBV (4/1), SF/PHBV (3/1), and SF/PHBV (2/1) nanofibers were 55.16 ± 12.38 nm, 75.93 ± 21.83 nm, 69.35 ± 21.55 nm, and 61.40 ± 12.31 nm, respectively. Fourier transform infrared (FTIR) spectroscopy and X-ray diffraction (XRD) were used to explore the microstructure of the electrospun SF/PHBV composite nanofiber. The crystallization ability of the composite nanofiber was greatly improved with the addition of PHBV. The results of thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) indicated that the thermal stability of SF was better than PHBV obviously, so SF could improve the thermal stability of the composite materials within a certain range. The mechanical properties of the electrospun nanofiber membranes were evaluated by using a universal testing machine. In general, the elongation of the composite nanofiber membranes decreased, and the breaking strength increased with the addition of PHBV. The small pore size of the nanofiber membranes ensured that they had good application prospects in the field of filtration and protection. When the spinning time was 1 h, the filtration efficiency of SF/PHBV/PLA composite materials remained above 95%. © 2021 The Textile Institute.

Recent advances of nanotechnology in COVID 19: A critical review and future perspective

The global anxiety and economic crisis causes the deadly pandemic coronavirus disease of 2019 (COVID 19) affect millions of people right now. Subsequently, this life threatened viral disease is caused due to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). However, morbidity and mortality of infected patients are due to cytokines storm syndrome associated with lung injury and multiorgan failure caused by COVID 19. Thereafter, several methodological advances have been approved by WHO and US-FDA for the detection, diagnosis and control of this wide spreadable communicable disease but still facing multi-challenges to control. Herein, we majorly emphasize the current trends and future perspectives of nano-medicinal based approaches for the delivery of anti-COVID 19 therapeutic moieties. Interestingly, Nanoparticles (NPs) loaded with drug molecules or vaccines resemble morphological features of SARS-CoV-2 in their size (60–140 nm) and shape (circular or spherical) that particularly mimics the virus facilitating strong interaction between them. Indeed, the delivery of anti-COVID 19 cargos via a nanoparticle such as Lipidic nanoparticles, Polymeric nanoparticles, Metallic nanoparticles, and Multi-functionalized nanoparticles to overcome the drawbacks of conventional approaches, specifying the site-specific targeting with reduced drug loading and toxicities, exhibit their immense potential. Additionally, nano-technological based drug delivery with their peculiar characteristics of having low immunogenicity, tunable drug release, multidrug delivery, higher selectivity and specificity, higher efficacy and tolerability switch on the novel pathway for the prevention and treatment of COVID 19. © 2022 The Author(s)

Biodegradable Electrospun Nanofiber Membranes as Promising Candidates for the Development of Face Masks.

Aerosol particles, such as the widespread COVID-19 recently, have posed a great threat to humans. Combat experience has proven that masks can protect against viruses; however, the epidemic in recent years has caused serious environmental pollution from plastic medical supplies, especially masks. Degradable filters are promising candidates to alleviate this problem. Degradable nanofiber filters, which are developed by the electrospinning technique, can achieve superior filtration performance. This review focuses on the basic introduction to air filtration, the general aspects of face masks, and nanofibers. Furthermore, the progress of the state of art degradable electrospun nanofiber filters have been summarized, such as silk fibroin (SF), polylactic acid (PLA), chitosan, cellulose, and zein. Finally, the challenges and future development are highlighted.

Using the concept of circular economy to reduce the environmental impact of COVID-19 face mask waste

COVID-19 pandemic has posed severe threats to the society globally. World Health Organization (WHO) guidelines suggest that people wear face masks as a precautionary measure daily. This has resulted in the generation of massive amounts of mask-associated waste in the environment. Owing to the criticality of the epidemic, there has not been a large-scale investigation on where to discard masks, making this situation daunting. As the pandemic continues, the use of masks continues to increase, repeated use and disposal of masks has become an imperative issue. Most disposable masks comprise chemical fibers in the filter layer. Without proper treatment and disposal, these large amounts of chemical waste will eventually flow into rivers or oceans, leading to serious pollution. Therefore, to reduce the negative effects on the marine environment, it is crucial that we produce reusable masks and reduce disposable wearing habits. This study aimed to resolve this challenge using textile materials created by recycling fish-scale waste. Functional and comfortable masks manufactured without chemical additives to achieve multiple functions can increase the willingness to wear and be reused. Hence, product use can be prolonged, and the use of disposable masks can be curtailed. The product manufactured herein is biodegradable in nature, thus conforming to the green sustainable initiative.

RESÍDUOS PLÁSTICOS E SUSTENTABILIDADE: REFLEXOS E IMPACTOS DA PANDEMIA DE COVID-19 NO CONTEXTO SOCIOCULTURAL E AMBIENTAL

Objetivo: O artigo buscou analisar os impactos e reflexos da pandemia de COVID-19 na gestão dos resíduos plásticos. Referencial teórico: A preocupação com a COVID-19 resultou em diversas medidas protetivas, como a determinação do uso de EPIs e restrições de circulação nos centros urbanos. Essas mudanças também impactaram padrões de geração e gestão de resíduos sólidos, especialmente de resíduos plásticos, cujos reflexos negativos nos aspectos socioambientais podem emergir, dado seu descarte inadequado. Método: Foi realizada uma revisão sistemática de literatura, nas bases de dados Scopus, Sage e Web of Science, com utilização do Methodi Ordinatio. Ao total, 22 estudos foram selecionados, compondo o portfólio de pesquisa. Resultados e conclusão: Os resultados demonstraram uma maior concentração de estudos que relacionam os resíduos plásticos nas regiões costeiras, especialmente provenientes de EPIs, e a poluição por microplásticos. Além disso, há uma preocupação com a geração de resíduos de embalagens pela alteração nos padrões de consumo, com o aumento da procura por serviços de e-commerce e delivery. Além de uma preocupação ambiental, destaca-se um problema de ordem social à longo prazo, devido à quebra de padrões de comportamentos sustentáveis na utilização de plástico descartável. Implicações da pesquisa: Soluções são propostas no sentido de utilização de plásticos biodegradáveis, reutilização de EPIs e novas tecnologias de tratamento de resíduos, além da mudança no comportamento social. Originalidade/valor: De um modo geral, o estudo fornece insights e promove reflexões sobre os desafios enfrentados no gerenciamento de resíduos plásticos durante a pandemia de COVID-19.Alternate :Purpose: The article aims to analyze the impacts and reflections of the COVID-19 pandemic on plastic waste management. Theoretical Framework: The concern with COVID-19 resulted in several protective measures, such as the use of PPE and movement restrictions in urban centers. These changes also affected patterns of generation and management of solid waste, especially plastic waste, whose negative effects on socio-environmental aspects may emerge due to its inadequate disposal. Method: We conducted a systematic literature review in the databases Scopus, Sage and Web of Science, employing the Methodi Ordinatio. The review selected 22 studies to compose the research portfolio. Results and conclusion: The results showed a higher concentration of studies on plastic waste in coastal regions, especially from PPE and microplastic pollution. Moreover, there is a concern with the generation of packaging waste by shifting consumption patterns with the increased demand for e-commerce and delivery services. Besides an environmental concern, a long-term social problem stands out regarding the breaking of sustainable behavior patterns in using disposable plastic. Research implications: We propose solutions involving the use of biodegradable plastics, reuse of PPE, and new waste treatment technologies, besides changes in social behavior. Originality/Value: Overall, the study provides insights and promotes reflections on the challenges faced in managing plastic waste during the COVID-19 pandemic.

Survey of the European yarn fairs for spring/summer 2023

The atmosphere at the European yarn fairs for spring/summer 2023 was positive, reflecting the fact that trade had begun to improve again after the apparel and textile industries had been heavily impacted by the COVID-19 pandemic during 2020 and 2021. Having said that, there remain economic uncertainties which continue to make it difficult to plan for upcoming seasons. These uncertainties are reflected in the colour trends for the spring/summer 2023 season. In particular, colours are restrained and mellow compared with previous seasons. That said, there is an abundance of novel knitwear yarns in the collections for the season, reflecting a playful spirit which was embraced at all of the European yarn fairs. There is also a strong focus in the collections on antiviral and antibacterial yarns, driven by an increase in consumer demand for these materials during the COVID-19 pandemic. Exhibitors at the fairs agreed that awareness of antiviral and antibacterial yarns had been brought to the forefront as a result of the pandemic and this had driven manufacturers to pursue innovation. Environmental sustainability continued to be a widely discussed and promoted topic at the fairs, and it was clear that manufacturers are pursuing opportunities for adding value through biodegradability. In particular, it is especially important for manufacturers to demonstrate the biodegradability of their yarns in marine environments. This trend is being driven by greater consumer awareness of the damage which is being caused to the environment by microfibres and the persistence of apparel and textile waste in the oceans. Yarns made from natural fibres, notably linen, merino wool and hemp, are prevalent in the collections for the spring/summer 2023 season and there is a particular focus on promoting the inherent properties of these fibres—including breathability, moisture management and thermoregulation. Also, traceability is high on the agenda for many manufacturers, and innovations in trace technology were plentiful at the fairs. © Textiles Intelligence Limited 2022.

Recent advances of chitosan-based polymers in biomedical applications and environmental protection

Interest in polymer-based biomaterials such as chitosan and its modifications and also the methods of their application in various fields of science is uninterruptedly growing. Owing to unique physicochemical, biological, ecological, physiological properties, such as biocompatibility, biodegradability, stability in the natural environment, non-toxicity, high biological activity, economic affordability, chelating of metal ions, high sorption properties, chitosan is used in various biomedical and industrial processes. The reactivity of the amino and hydroxyl groups in the structure makes it more interesting for diverse applications in drug delivery, tissue engineering, wound healing, regenerative medicine, blood anticoagulation and bone, tendon or blood vessel engineering, dentistry, biotechnology, biosensing, cosmetics, water treatment, agriculture. Taking into account the current situation in the world with COVID-19 and other viruses, chitosan is also active in the form of a vaccine system, it can deliver antibodies to the nasal mucosa and load gene drugs that prevent or disrupt the replication of viral DNA/RNA, and deliver them to infected cells. The presented article is an overview of the nowaday state of the application of chitosan, based on literature of recent years, showing importance of fundamental and applied studies aimed to expand application of chitosan-based polymers in many fields of science.

Smart Material Choice: The Importance of Circular Design Strategy Applications for Bio-Based Food Packaging Preproduction and End-of-Life Life Cycle Stages

This article provides a systematic literature review on the integrated approach of bio-based plastic food packaging in a circular economy. It focuses on the following key areas: (1) the role of bio-based plastic food packaging in a circular product design strategy and material choice in the preproduction life cycle stage;(2) the role of bio-based plastic food packaging in circular resource management systems and the product disposal life cycle stage;and (3) an optimal bio-based plastic food packaging application in regard to prioritising end-of-life treatment. While there are dedicated publications on the role of packaging in a circular economy, circular packaging design, packaging waste management, and bio-origin plastic applications in food packaging, this article aims to provide an integrated review and recommendations on the best bio-based plastic food packaging material selection, applications based on a circular economy, and scenarios on waste/resource management that prioritise end-of-life treatment. Three of the current most popular bio-based plastic materials in the flexible and rigid food packaging categories were selected: starch blends, bio-PE, and PLA for flexible food packaging and PLA, bio-PET, and bio-PE for rigid packaging. This article highlights the fact that a smart material choice in the circular design strategy is a key factor that has a direct impact on the last packaging life cycle stage (disposal), and concludes that bio-based plastic materials are a way to close the food packaging loop, either by re-use or recycling. This article also provides recommendations on the best bio-based plastic food packaging material selection, and applications based on the circular economy and waste management that prioritise end-of-life treatment. The research results indicate a research niche for the application of re-usable biodegradable materials in food packaging. The findings of this research allow product designers and packaging companies to advance the understanding of the most efficient bio-based plastic food packaging integration into the circular economy via decision making of product material choice and end-of-life treatment. Based on the results of this article, scholars can develop new themes for further research.

Bio-Based Materials Riding the Wave of Sustainability: Common Misconceptions, Opportunities, Challenges and the Way Forward

Solid waste disposal, particularly of plastic and rubber, significantly impacts the environment and human health;thus, encouraging consumers to u sustainable alternatives is essential to ensure a resilient future. In recent decades, bio-based material research has primarily focused on bioplastics and, accordingly, current knowledge of alternative sustainable materials (such as biorubber) is fragmented, with consumer misconceptions posing a key challenge. This paper provides a comprehensive overview of the fundamentals of bio-based materials, in addition to common misconceptions about them. The findings of a public survey that aimed to assess consumers’ attitudes towards, as well as their awareness and perceptions of, conventional and sustainable alternative materials, particularly oxo-biodegradable rubbers, are also reported in this paper. Despite their unfamiliarity with the terms ‘bio-based’ and ‘oxo-biodegradable’, most respondents had a positive view of bio-based products and expressed an interest in reducing their use of conventional products in favour of sustainable alternatives. The results also revealed that consumers are willing to spend more on sustainable alternatives because they are aware of the environmental issues associated with solid waste. This study provides new insights into knowledge gaps and challenges that must be addressed to promote the prudent use of sustainable materials in a fast-changing world.

Biofuel Generation from Potato Peel Waste: Current State and Prospects

Growing environmental concerns, increased population, and the need to meet the diversification of the source of global energy have led to increased demand for biofuels. However, the high cost of raw materials for biofuels production has continued to slow down the acceptability, universal accessibility, and affordability of biofuels. The cost of feedstock and catalysts constitutes a major component of the production cost of biofuels. Potato is one of the most commonly consumed food crops among various populations due to its rich nutritional, health, and industrial benefits. In the current study, the application of potato peel waste (PPW) for biofuel production was interrogated. The present state of the conversion of PPW to bioethanol and biogas, through various techniques, to meet the ever-growing demand for renewable fuels was reviewed. To satisfy the escalating demand for biohydrogen for various applications, the prospects for the synthesis of biohydrogen from PPW were proposed. Additionally, there is the potential to convert PPW to low-cost, ecologically friendly, and biodegradable bio-based catalysts to replace commercial catalysts. The information provided in this review will enrich scholarship and open a new vista in the utilization of PPW. More focused investigations are required to unravel more avenues for the utilization of PPW as a low-cost and readily available catalyst and feedstock for biofuel synthesis. The application of PPW for biofuel application will reduce the pump price of biofuels, ensure the appropriate disposal of waste, and contribute towards environmental cleanliness.

Preparing and Characterizing Novel Biodegradable Starch/PVA-Based Films with Nano-Sized Zinc-Oxide Particles for Wound-Dressing Applications

Given recent worldwide environmental concerns, biodegradability, antibacterial activity, and healing properties around the wound area are vital features that should be taken into consideration while preparing biomedical materials such as wound dressings. Some of the available wound dressings present some major disadvantages. For example, low water vapor transmission rate (WVTR), inadequate exudates absorption, and the complex and high environmental cost of the disposal/recycling processes represent such drawbacks. In this paper, starch/polyvinyl alcohol (PVA) material with inserted nano-sized zinc-oxide particles (nZnO) (average size ≤ 100 nm) was made and altered using citric acid (CA). Both ensure an efficient antibacterial environment for wound-dressing materials. The film properties were assessed by UV–Vis spectrometry and were validated against the UV light transmission percentage of the starch/ polyvinyl alcohol (PVA)/ zinc-oxide nanoparticles (nZnO) composites. Analyses were conducted using X-ray Spectroscopy (EDX) and scanning electron microscopy (SEM) to investigate the structure and surface morphology of the materials. Moreover, to validate an ideal moisture content around the wound area, which is necessary for an optimum wound-healing process, the water vapor transmission rate of the film was measured. The new starch-based materials exhibited suitable physical and chemical properties, including solubility, gel fraction, fluid absorption, biodegradability, surface morphology (scanning electron microscopy imaging), and mechanical properties. Additionally, the pH level of the starch-based/nZnO film was measured to study the prospect of bacterial growth on this wound-dressing material. Furthermore, the in vitro antibacterial activity demonstrated that the dressings material effectively inhibited the growth and penetration of bacteria (Escherichia coli, Staphylococcus aureus).

Piezoelectric Nanofiber Membrane for Reusable, Stable, and Highly Functional Face Mask Filter with Long-Term Biodegradability

The emergence of the SARS-CoV-2 pandemic and airborne particulate matter (PM) pollution has led to remarkably high demand for face masks. However, conventional respirators are intended for single use and made from nondegradable materials, causing serious concern for a plastic-waste environmental crisis. Furthermore, these facemasks are weakened in humid conditions and difficult to decontaminate. Herein, a reusable, self-sustaining, highly effective, and humidity-resistant air filtration membrane with excellent particle-removal efficiency is reported, based on highly controllable and stable piezoelectric electrospun poly (l-lactic acid) (PLLA) nanofibers. The PLLA filter possesses a high filtration efficiency (>99% for PM 2.5 and >91% for PM 1.0) while providing a favorable pressure drop (≈91 Pa at normal breathing rate) for human breathing due to the piezoelectric charge naturally activated by respiration through the mask. The filter has a long, stable filtration performance and good humidity resistance, demonstrated by a minimal declination in the filtration performance of the nanofiber membrane after moisture exposure. The PLLA filter is reusable via common sterilization tools (i.e., an ultrasonic cleaning bath, autoclave, or microwave). Moreover, a prototype of a completely biodegradable PLLA nanofiber-based facemask is fabricated and shown to decompose within 5 weeks in an accelerated degradation environment. © 2022 Wiley-VCH GmbH

Two Birds with One Stone: Bioplastics and Food Waste Anaerobic Co-Digestion

Following the BBC’s Blue Planet II nature documentary series on marine ecosystems, plastic packaging has come under public fire, with consumers demanding greener alternatives. The biodegradable properties of some bioplastics have offered a potential solution to the global challenge of plastic pollution, while enabling the capture of food waste through anaerobic digestion as a circular and energy-positive waste treatment strategy. However, despite their increasing popularity, currently bioplastics are being tested in environments that do not reflect real-life waste management scenarios. Bioplastics find their most useful, meaningful and environmentally-sound application in food packaging—why is there so little interest in addressing their anaerobic co-digestion with food waste? Here, we provide a set of recommendations to ensure future studies on bioplastic end-of-life are fit for purpose. This perspective makes the link between the environmental sustainability of bioplastics and the role of food waste anaerobic digestion as we move towards an integrated food–energy–water–waste nexus. It shines light on a novel outlook in the field of bioplastic waste management while uncovering the complexity of a successful path forward. Ultimately, this research strives to ensure that the promotion of bioplastics within a circular economy framework is supported across waste collection and treatment stages.