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Graphical abstract Numerous viral infections are common among humans, and some can lead to death. Even though conventional antiviral agents are beneficial in eliminating viral infections, they may lead to side effects or physiological toxicity. Silver nanoparticles and nanocomposites have been demonstrated to possess inhibitory properties against several pathogenic microbes, including archaea, bacteria, fungi, algae, and viruses. Its pronounced antimicrobial activity against various microbe-mediated diseases potentiates its use in combating viral infections. Notably, the appropriated selection of the synthesis method to fabricate silver nanoparticles is a major factor for consideration as it directly impacts antiviral efficacy, level of toxicity, scalability, and environmental sustainability. Thus, this article presents and discusses various synthesis approaches to produce silver nanoparticles and nanocomposites, providing technological insights into selecting approaches to generate antiviral silver-based nanoparticles. The antiviral mechanism of various formulations of silver nanoparticles and the evaluation of its propensity to combat specific viral infections as a potential antiviral agent are also discussed.

Introduction The 2019-novel coronavirus disease (COVID-19) is an intractable global health challenge resulting in an aberrant rate of morbidity and mortality worldwide. The mode of entry for SARS-CoV-2 into host cells occurs through clathrin-mediated endocytosis. As part of the efforts to mitigate COVID-19 infections, rapid and accurate detection methods, as well as smart vaccine and drug designs with SARS-CoV-2 targeting capabilities are critically needed. This systematic review aimed to present a good mapping between the structural and functional characteristics of aptamers and their potential applications in COVID-19 theranostics. Methods In this study, extensive discussions into the potential development of aptameric systems as robust theranostics for rapid mitigation of the virulent SARS-CoV-2 was made. Information required for this study were extracted from a systematic review of literature in PubMed, SCOPUS, Web of Science (WOS), and other official related reports from reputable organisations. Results The global burden of COVID-19 pandemic was discussed including the progress in rapid detection, repurposing of existing antiviral drugs, and development of prophylactic vaccines. Aptamers have highly specific and stable target binding characteristics which can be generated and engineered with less complexity for COVID-19 targeted theranostic applications. Conclusions There is an urgent need to develop safe innovative biomedical technologies to mitigate the dire impact of COVID-19 on public health worldwide. Research advances into aptameric systems bode well with the fact that they can be engineered for the development of effective and affordable diagnostics, therapeutics and prophylactic vaccines for SARS-CoV-2 and other infectious pathogens.

Diabetes mellitus, particularly type 2 diabetes, is a major global health issue, the prevalence of which seems to be on the rise worldwide. Interventions such as healthy diet, physical activity, maintaining a healthy weight, and medication (for those with a diagnosis of diabetes) are among the most effective strategies to prevent and control diabetes. Three-quarters of patients diagnosed with diabetes are in countries with poor financial infrastructure, nutritional awareness and health care systems. Concomitantly, the cost involved in managing diabetes through the intake of antidiabetic drugs makes it prohibitive for majority of patients. Food protein-derived bioactive peptides have the potential of being formulated as nutraceuticals and drugs in combating the pathogenesis and pathophysiology of metabolic disorders with little or "no known" complications in humans. Coupled with lifestyle modifications, the potential of bioactive peptides to maintain normoglycemic range is actualized by influencing the activities of incretins, DPP-IV, α-amylase, and α-glucosidase enzymes. This article discusses the biofunctionality and clinical implications of anti-diabetic bioactive peptides in controlling the global burden of diabetes.

This study investigated the properties of films or bioplastics fabricated using a wet processing method from yellow pea protein isolate (YPI) and protein concentrate (YPC) for potential application in food packaging. The wet processing method included mixing the protein with water and glycerol followed by casting and drying the films in a humidity- and temperature-controlled chamber. Whey protein isolate (WPI) and a film from a blend of equal amounts of YPI and WPI, labelled as YPI + WPI, were also studied. Fourier transform-infra red analysis revealed that films from YPI, YPC, WPI and YPI + WPI were formed by protein polymerisation with the plasticiser, glycerol, via hydrophobic and hydrophilic interactions. The protein films had contact angles of YPC > YPI + WPI > YPI, whereas the mechanical and thermal resilience of films formulated from YPI, YPC and the protein blend were comparable to the properties of WPI-based films. The findings demonstrate that yellow pea proteins can be used as biomaterials to develop protein and protein-blend films or bioplastics for food packaging and edible applications.

The palm oil industry has been one of the major economic contributors for Malaysia over the last decade. While contributing to the country's economic growth, the industry has inevitably produced a significant amount of waste materials which are harmful to the environment. Oil palm boiler ashes (OPBA) generated from boiler in mills are disposed in open landfills which are easily carried away by the wind. The disposed ash pollutes the air while spent earth, when left in landfills, produce a pungent odour. The present work investigated the possibility of refining palm oil with raw OPBA and pelletized OPBA as alternate bleaching adsorbents. The performance of different types OPBA (raw, enhanced and pelletized) was investigated to determine their bleaching efficiencies on carotenoid removal at various operating conditions. Crude palm oil samples were refined with these OPBA and compared with commercial bleaching earth to investigate the final refined oil colours. A final refined oil colour of 4.0R was obtained using 0.05 wt% of enhanced OPBA when bleached at 110 °C for 45 min under constant agitation (300 rpm) and subsequently deodorized at 265 °C for 1 h. This study has indicated that the use of enhanced OPBA which could achieve more than high removal of carotenoid could substitute commercial bleaching earths to produce a comparable final refined oil colour rating. The successful substitution of OPBA to replace the conventional bleaching earth in oil refining could significantly reduce the production cost. This is also a sustainable solution for the edible oil processing industries to mitigate the solid waste and contributes to a cleaner environment.

Biocarriers are pivotal in enhancing the reusability of biocatalyst that would otherwise be less economical for industrial application. Ever since the induction of enzymatic technology, varied materials have been assessed for their biocompatibility with enzymes of distinct functionalities. Herein, cellulase was immobilized onto polymethacrylate particles (ICP) as the biocarrier grafted with ethylenediamine (EDA) and glutaraldehyde (GA). Carboxymethyl cellulose (CMC) was used as a model substrate for activity assay. Enzyme immobilization loading was determined by quantifying the dry weight differential of ICP (pre-& post-immobilization). Cellulase was successfully demonstrated to be anchored upon ICP and validated by FTIR spectra analysis. The optimal condition for cellulase immobilization was determined to be pH 6 at 20 °C. The maximum CMCase activity was achieved at pH 5 and 50 °C. Residual activity of ∼50% was retained after three iterations and dipped to ∼18% on following cycle. Also, ICP displayed superior pH adaptability as compared to free cellulase. The specific activity of ICP was 65.14 ± 1.11% relative to similar amount of free cellulase.

Diversification of plant-based food sources is necessary to improve global food and nutritional security. Pulses have enormous nutritional and health benefits in preventing malnutrition and chronic diseases while contributing positively to reducing environmental footprint. Pulses are rich in diverse nutritional and non-nutritional constituents which can be classified as bioactive compounds due to their biological effect. These bioactive compounds include but are not limited to proteins, dietary fibres, resistant starch, polyphenols, saponins, lectins, phytic acids, and enzyme inhibitors. While these compounds are of importance in ensuring food and nutritional security, some of the bioactive constituents have ambivalent properties. These properties include having antioxidant, anti-hypertensive and prebiotic effects. Others have a deleterious effect of decreasing the digestibility and/or bioavailability of essential nutrients and are therefore termed antinutritional factors/compounds. Various processing techniques exist to reduce the content of antinutritional factors found in pulses. Traditional processing of pulses comprises soaking, dehulling, milling, germination, fermentation, and boiling, while examples of emerging processing techniques include microwaving, extrusion, and micronization. These processing techniques can be tailored to purpose and pulse type to achieve desired results. Herein, the nutritional qualities and properties of bioactive compounds found in pulses in meeting the sustainable development goals are presented. It also discusses the effect of processing techniques on the nutritional and non-nutritional constituents in pulses as well as the health and environmental benefits of pulse-diet consumption. Major challenges linked to pulses that could limit their potential of being ideal crops in meeting the sustainable development goal 2 agenda are highlighted.

Consumption of milk-derived whey proteins has been demonstrated to have insulin-sensitizing effects in mice and humans, in part through the generation of bioactive whey peptides. While whey peptides can prevent insulin resistance in vitro, it is unclear whether consumption of whey peptides can prevent obesity-induced metabolic dysfunction in vivo. We sought to determine whether whey peptides consumption can protect from high fat (HF) diet-induced obesity and dysregulation of glucose homeostasis. Male C57BL/6J mice were fed either a low or HF diet for 13 weeks. HF diet fed mice were provided drinking water with no addition (control), undigested whey protein isolate (WPI, 1 mg ml-1) or whey protein hydrolysate (WPH, 1 mg ml-1) throughout the diet regimen. Mice consuming WPH gained more body weight and were more glucose intolerant compared to those consuming WPI or water only. Despite increased body weight gain, perigonadal adipose tissue weight and lipid accumulation were unchanged. However, excess lipids accumulated ectopically in the liver and skeletal muscle in mice consuming WPH, which was associated with elevated inflammatory markers systemically and in adipose tissue, liver, and skeletal muscle. In skeletal muscle, mitochondrial fat oxidation and electron transport chain proteins were decreased with WPH consumption, indicative of mitochondrial dysfunction. Taken together, our results demonstrate that WPH, but not WPI, exacerbates HF-induced body weight gain and impairs glucose homeostasis, which is accompanied by increased inflammation, ectopic fat accumulation and mitochondrial dysfunction. Thus, our results argue against the use of dietary whey peptide supplementation as a preventative option against HF diet-induced metabolic dysfunction.

Lipids represent a major algal biochemical with an extensive range of applications including biodiesel synthesis. Biodiesel constitutes ‘fatty acid methyl esters’ (FAME) arising from the transesterification of lipids. Among algal lipids, neutral or true lipids such as ‘triacylglycerols’ (TAGs) are important for generating high quality and stable biodiesel fuel with enhanced calorific value. New and improved physicochemical lipid extraction methods are highly important to enable the selective generation of true lipids from algal biomass. This chapter presents an overview of the diverse conventional and advanced extraction methods used as efficient approaches for lipid extraction from algae. The impact of nanotechnology for enhanced lipid extraction is discussed.

With heightened interest of consumers in a green environment and sustainable production processes, microalgae have received significant attention as new model organisms for various commercial food protein applications. Due to their high tolerance to diverse and harsh environmental conditions, microalgae proteins have unique physicochemical and technofunctional properties that can be used in the formulation of new food/feed products. In addition, microalgae have high protein content that can be commercially extracted for the generation of bioactive peptides. However, due to the rigid cell wall structures and high viscosity, microalgae have low protein digestibility. Nonetheless, this challenge can be curtailed through cell disruption pretreatment approaches, which can increase the protein extraction yield while preserving the molecular integrity of the extracted proteins. This chapter presents a holistic discussion of the extraction, technofunctionality, and application of microalgae proteins and bioactive peptides in the food industry.

Protein-based bioplastics have attracted great interest owing to their sustainable sources, biodegradability and safe use for food and pharmaceutical applications. Sources of dietary proteins are ubiquitous and include, but are not limited to, microalgae, legumes, pulses, cereals, insects and dairy products. Dietary proteins have structural features that confer unique properties and functionalities in the formation of biodegradable bioplastics. Bioplastics can be formed from dietary proteins through two main techniques, wet processing and dry processing. Dietary proteins can be modified with suitable chemistries and additives to enhance their features such as aesthetics and mechanical, thermal, chemical and antimicrobial properties. Further, the properties of bioplastics can be altered based on processing parameters such as pH, temperature, concentration, type of protein precursors and plasticizers. In this chapter, a comprehensive discussion of dietary proteins and their physicochemical properties as suitable alternatives for the formation of bioplastics is presented. The potential of using protein bioplastics as edible and active packages is also discussed.

This chapter archives the state of the art concerning crucial drug delivery strategies aiding in cardiovascular therapies, including their benefits and associated challenges. The aspects which govern vascular transport and cardiovascular drug targeting have been reviewed, both from configuration and flow perspectives. In addition, the role of extracellular vesicles and exosomes, as well as the suitability of ultrasound and microbubble-mediated delivery, has been discussed. Current advancements made in the nanomedicine domain, with relevant applications pertaining to diverse categories, have been collated and discussed. A special focus has been laid on the applications of aptamers in cardiovascular drug targeting, particularly with respect to conjugation with specific coagulation factors and proteins. It also captures the potential and promises of the next generation of targeted strategies, with an eye on the foreseeable future.

Advances in the field of biotechnology have resulted in the emergence of genetic engineering methods whereby the genetic material of an organism can be manipulated or redesigned to yield desired products. Recently, there has been an increasing trend to elevate the existence of specific nutrients in edible genetically modified (GM) crops to be utilized as therapeutic agents. In this case, GM crops serve as a cell factory to generate such nutrients or necessary biomolecules and can be delivered to patients as a novel oral delivery approach for drugs and vaccines. On the other hand, GM foods are fraught with significant challenges with regard to human and animal health and disruption of the ecosystem. This chapter aims to provide an overview of GM foods, methods to produce therapeutic proteins in GM foods and various types of therapeutic proteins produced via GM crops or foods. The limitations, potential allergenicity and future of GM foods are also discussed.

Microalgae are underutilized organisms with multifaceted bio-relevance beyond their potential as sources of sustainable biofuels. Microalgae are unique sources of bioactive compounds and proteins with nutritional, functional, and health benefits. Although the use of microalgae as food and feed dates back several centuries, strategic scientific evaluations of the nutritional value and health benefits have increasingly garnered attention in recent times, especially as sustainable, alternative sources of dietary protein. Major criteria in evaluating the nutritional value of novel food and feed sources are the protein content, amino acid profile, digestibility, protein utilization, and the protein needs of consumers. The nutritional value of microalgae is affected by biotic and abiotic factors and genomic variation between species. Using endogenous and exogenous proteases, microalgal proteins can be hydrolyzed to generate bioactive peptides with potential physiological effects in the human body, such as opioid-like, antithrombotic, immunomodulatory, and antihypertensive activities. One major challenge faced when using whole microalgae as a dietary protein source is poor digestibility, which is mostly due to the rigid and recalcitrant nature of many microalgal cell walls. This challenge can be circumvented with chemical, mechanical, and enzymatic pretreatments of microalgal biomass prior to protein extraction or food/feed product development. This chapter discusses the nutritional value and health benefits of microalgae proteins and peptides as well as the current challenges and future direction in protein assessment methods.

The introduction of aptameric ligands onto disk-monolithic adsorbent, representing a unique strategy for convective isolation of target molecules with high specificity and selectivity, is investigated for the first time. Experimental results showed that the disk monolith possessed a good permeability of 1.67 ± 0.05 × 10–14 m2 (RSD = 3.2%). The aptameric ligand density for the aptamer-modified disk monolith was 480 pmol/uL. Chromatographic analysis of the aptamer disk-monolith efficiency showed an optimum linear velocity of 126 cm/min (≈0.25 mL/min) at room temperatures 25 ± 2°C. The theoretical number of plates corresponding to the optimum linear velocity was 128.2 with an height equivalent to the theoretical plate of 0.022 mm. The disk aptamer-immobilised monolithic system demonstrated good selectivity and isolation of thrombin from non-targets.

Aptamers are single stranded nucleic acids with specific target-binding functionalities, biophysical and biochemical properties. The binding performance of aptamers to their cognate targets is influenced by the physicochemical conditions of the binding system particularly in relation to biomolecular charge distribution and hydrodynamic conformations in solution. Herein, we report the use of zeta potential measurements to characterise the surface charge distribution, biomolecular hydrodynamic size and the binding performance of a 15-mer thrombin binding aptamer (TBA) to thrombin under various physicochemical conditions of pH, temperature, monovalent (K + ) and divalent (Mg 2+ ) cation concentrations. Charge distribution analysis demonstrated time dependence in the formation of stable TBA-thrombin and TBA-thrombin-metal ion complexes. TBA was characterised to be most stable in pH above 9. The presence of monovalent and divalent metal ions reduced the electronegativity of TBA through electrostatic interactions, and this demonstrated to improve binding characteristics. TBA-thrombin complexes generated under different physicochemical conditions showed varying surface charge distributions. The stability of TBA-thrombin complex investigated using Scatchard analysis showed that the presence of K + increased the binding performance by displaying a positive cooperativity relationship. The presence of Mg 2+ showed a concave upward trend, potentially caused by heterogeneity in binding.

Polymethacrylate monoliths are synthetic adsorbents with macroporous and mesoporous interconnected channels that can be engineered to target the hydrodynamic features of a wide range of molecular species. However, rigorous study into the effect of synthesis conditions on their thermal stability is limited. This work attempts to characterise the influence of key synthesis process variables on the stability of polymethacrylate monoliths using thermogravimetric analysis at a heating rate of 10 °C/min. Experimental results showed that the thermal stability of polymethacrylate monoliths increased with decreasing polymerisation temperature from 85 to 65 °C. Increasing the total porogen (P) to monomer (M) ratio increased the thermal stability of the monolith by >62% and >50% for P40/M60–P60/M40 and P60/M40–P80/M20, respectively. The impact of the initiator concentration, monomer variation, biporogen ratio, washing and activation of the monoliths was investigated. Nuclear magnetic resonance analyses conducted confirmed the hydrolysis of epoxy moieties on the monolith. © 2017 Curtin University of Technology and John Wiley & Sons, Ltd.

The thermo-molecular mechanisms associated with free radical synthesis of polymethacrylate monoliths offer an effective pathway to tune their pore characteristics. In this work, thermogravimetric analyses were used for ex situ characterization of polymethacrylate monoliths synthesised from ethylene glycol dimethacrylate (EDMA) and glycidyl methacrylate (GMA). Apparent activation energies of the polymeric monoliths were determined by using Ozawa-Flynn-Wall (OFW) and Kissinger-Akahira-Sunose (KAS) isoconversional methods. The number of degradation stages for the polymers were observed to be as follows: homopolymeric GMA and EDMA (2 degradation stages each) and polymeric EDMA-co-GMA monoliths (3 degradation stages). The relationship between apparent activation energy and extent of conversion showed that the degradation of monoliths is based on a complex multi-step reaction rather than a single reaction model. Kinetic parameters showed that an increase in the composition of EDMA and GMA above 20% significantly enhances the thermal stability of polymeric EDMA-co-GMA monoliths under elevated non-isothermal conditions. E40/G60 and E60/G40 monoliths were identified as the most thermally stable monoliths from the kinetic analyses. This article is protected by copyright. All rights reserved

The food and health applications of bioactive peptides have grown remarkably in the past few decades. Current elucidations have shown that bioactive peptides have unique structural arrangement of amino acids, conferring distinct functionalities, and molecular affinity characteristics. However, whereas interest in the biological potency of bioactive peptides has grown, cost-effective techniques for monitoring the structural changes in these peptides and how these changes affect the biological properties have not grown at the same rate. Due to the high binding affinity of aptamers for other biomolecules, they have a huge potential for use in tracking the structural, conformational, and compositional changes in bioactive peptides. This review provides an overview of bioactive peptides and their essential structure-activity relationship. The review further highlights on the types and methods of synthesis of aptamers before the discussion of the prospects, merits, and challenges in the use of aptamers for bioaffinity interactions with bioactive peptides.

Food-derived proteins are considered ideal materials for the development of encapsulation and delivery system for bioactive ingredients due to their biophysicochemical properties. The size of the protein-delivery systems in the intestinal media is critical in ensuring effective biophysicochemical characteristics such as biorecognition, biocompatibility, bioavailability, bioadhesion and stability. As such, it is important to understand the nature, process and characteristics of different nanoformulations produced with food-derived proteins, together with their drawbacks in food, pharmaceutical and biomedical applications. Current techniques used in the design of protein-based nanodelivery system include nanoemulsificaiton, coacervation, antisolvent precipitation, electrospraying and electrospinning. Brief descriptions of these techniques are presented in this paper, as well as some key characteristics of the resulting nanoparticles. The drawback of individual techniques is also discussed for the consideration of food scientists and biotechnologists who design nanodelivery systems for bioactive ingredients.

Bleaching is a vital step in crude palm oil (CPO) processing due to its importance for both decolourisation and removal of impurities present in the oil. The commonly used material for CPO bleaching is bleaching earth. However, there are associated environmental issues due to its disposal without pre-treatment, and the retention of significant quantities of oil during the bleaching process. It is therefore imperative to research into viable alternative bleaching materials which are economical, readily available and able to undergo successive regeneration while minimizing oil loss. The present work probed the performance of enhanced oil palm ash (OPA), as an alternate bleaching adsorbent. The performance of the bleaching process was investigated by engineering critical process parameters such as stirring speed, adsorbent dosage, regenerability and ash particle sizes. The effective particle size of OPA was determined to be 212–300 μm, resulting in a maximum bleaching efficiency of 97.3%. A stirring speed of 800 rpm was optimal irrespective of the adsorbent particle size. In addition, a high adsorbent-to-CPO dosage ratio was identified to be effective for successive numbers of regeneration with less retention of oil. Indications from this analyses are that a higher bleaching performance can be obtained by optimizing relevant process conditions of OPA as an adsorbent.

Bioavailability of bioactive peptides (BAPs) represents the amount of peptides absorbed through normal pathways, after oral intake, and distributed in target tissues to exhibit bioactive properties. The small intestine is the primary location of the gastrointestinal tract where peptide absorption mainly occurs. BAPs are beneficial to health upon reaching their physiological sites of action without structural changes. Despite the rapid and dynamic evolvement of research into food peptides, there is still a knowledge gap regarding their bioaccessibility and bioavailability for systemic circulation to targeted organs. Beside the digestive actions of endogenous proteases and peptidases, chemical and nutritional compositions of the food matrix and their physical forms (e.g., liquid, puree, gel, solid) are also critical factors that can influence the interactions, digestibility, bioaccessibility and bioavailability of BAPs. Detailed understanding of such food matrix factors can be explored for enhancing the bioavailability of BAPs and achieving their positive health effects.

Peptides are important compounds used in the development of functional biomaterials, functional foods and nutraceuticals. The functional and bioactive properties of peptides are directly linked to their structural features, including molecular size, presence or absence of charges, amino acid sequence, hydrophobicity, and hydrophilicity. The role of peptide structures in their bioactivities and functionalities is still emerging. Some bioactive peptides have undesirable taste, which can influence consumer interests in novel peptide-based food applications. In this review, we discussed the role of peptide hydrophobicity in their bioavailability, bioactivity, bitterness property, emulsion stability, aggregation and self-assembly for application in novel food formulations and nutraceutical/ drug delivery.

Immobilisation of aptameric ligands on solid stationary supports for effective binding of target molecules requires understanding of the relationship between aptamer-polymer interactions and the conditions governing the mass transfer of the binding process. Herein, key process parameters affecting the molecular anchoring of a thrombin-binding aptamer (TBA) onto polymethacrylate monolith pore surface, and the binding characteristics of the resulting macroporous aptasensor were investigated. Molecular dynamics (MD) simulations of the TBA-thrombin binding indicated enhanced Guanine 4 (G4) structural stability of TBA upon interaction with thrombin in an ionic environment. Fourier-transform infrared spectroscopy and thermogravimetric analyses were used to characterise the available functional groups and thermo-molecular stability of the immobilised polymer generated with Schiff-base activation and immobilisation scheme. The initial degradation temperature of the polymethacrylate stationary support increased with each step of the Schiff-base process: poly(Ethylene glycol Dimethacrylate-co-Glycidyl methacrylate) or poly(EDMA-co-GMA) [196.0 °C (±1.8)]; poly(EDMA-co-GMA)-Ethylenediamine [235.9 °C (±6.1)]; poly(EDMA-co-GMA)-Ethylenediamine-Glutaraldehyde [255.4 °C (±2.7)]; and aptamer-modified monolith [273.7 °C (±2.5)]. These initial temperature increments reflected in the associated endothermic energies were determined with differential scanning calorimetry. The aptameric ligand density obtained after immobilisation was 480 pmol/μL. Increase in pH and ionic concentration affected the surface charge distribution and the binding characteristics of the aptamer-modified disk-monoliths, resulting in the optimum binding pH and ionic concentration of 8.0 and 5 mM Mg2+, respectively. These results are critical in understanding and setting parametric constraints indispensable to develop and enhance the performance of aptasensors.