Alginate-based materials for enzyme encapsulation

Enzyme encapsulation in metal-organic frameworks using spray drying for enhanced stability and controlled release: A case study of phytase

Encapsulating enzymes in metal-organic frameworks is a common practice to improve enzyme stability against harsh conditions. However, the synthesis of enzyme@MOFs has been primarily limited to small-scale laboratory settings, hampering their industrial applications. Spray drying is a scalable and cost-effective technology, which has been frequently used in industry for large-scale productions. Despite these advantages, its potential for encapsulating enzymes in MOFs remains largely unexplored, due to challenges such as nozzle clogging from MOF particle formation, utilization of toxic organic solvents, controlled release of encapsulated enzymes, and high temperatures that could compromise enzyme activity. Herein, we present a novel approach for preparing phytase@MIL-88 A using solvent-free spray drying. This involves atomizing two MOF precursor solutions separately using a three-fluid nozzle, with enzyme release controlled by manipulating defects within the MOFs. The physicochemical properties of the spray dried particles are characterized using X-ray diffraction, Fourier-transform infrared spectroscopy, and scanning electron microscopy. Leveraging the efficiency and scalability of spray drying in industrial production, this scalable encapsulation technique holds considerable promise for broad industrial applications.

Advances in aldo-keto reductases immobilization for biocatalytic synthesis of chiral alcohol

Chiral alcohols are essential building blocks of numerous pharmaceuticals and fine chemicals. Aldo-keto reductases (AKRs) constitute a superfamily of oxidoreductases that catalyze the reduction of aldehydes and ketones to their corresponding alcohols using NAD(P)H as a coenzyme. Knowledge about the crucial roles of AKRs immobilization in the biocatalytic synthesis of chiral alcohols is expanding. Herein, we reviewed the characteristics of various AKRs immobilization approaches, the application of different immobilization materials, and the prospects of continuous flow bioreactor construction by employing these immobilized biocatalysts for synthesizing chiral alcohols. Finally, the opportunities and ongoing challenges for AKR immobilization are discussed and the outlook for this emerging area is analyzed.

Multifunctional polyaniline modified calcium alginate aerogel membrane with antibacterial, oil-water separation, dye and heavy metal ions removal properties for complex water purification

With the rapid development of urbanization, the discharge of industrial wastewater has led to increasingly critical water pollution issues. Additionally, heavy metals, organic dyes, microorganisms and oil pollution often coexist and have persistence and harmfulness. Developing materials that can treat these complex pollutants simultaneously has important practical significance. In this study, a calcium alginate-based aerogel membrane (PANI@CA membrane) was prepared by spraying, polymerization, Ca2+ cross-linking and freeze-drying using aniline and sodium alginate as raw materials. Oil-water emulsion can be separated by PANI@CA membrane only under gravity, and the separation efficiency was as high as 99 %. At the same time, the membrane can effectively intercept or adsorb organic dyes and heavy metal ions. The removal rates of methylene blue and Congo red were above 92 % and 63 % respectively even after ten times of cyclic filtration. The removal rate of Pb2+ was up to 95 %. In addition, PANI@CA membrane shows excellent photothermal conversion ability, and it can effectively kill Staphylococcus aureus under 808 nm laser irradiation. PANI@CA membrane has the advantages of low cost, simple preparation, good stability and high recycling ability, and has potential application prospects in wastewater treatment.

Probiotics for Aquaculture: Hope, Truth, and Reality

The use of microorganisms as beneficial crops for human and animal health has been studied for decades, and these microorganisms have been in practical use for quite some time. Nowadays, in addition to well-known examples of beneficial properties of lactic acid bacteria, bifidobacteria, selected Bacillus spp., and yeasts, there are several other bacteria considered next-generation probiotics that have been proposed to improve host health. Aquaculture is a rapidly growing area that provides sustainable proteins for consumption by humans and other animals. Thus, there is a need to develop new technologies for the production practices associated with cleaner and environment-friendly approaches. It is a well-known fact that proper selection of the optimal probiotics for use in aquaculture is an essential step to ensure effectiveness and safety. In this critical review, we discuss the evaluation of host-specific probiotics in aquaculture, challenges in using probiotics in aquaculture, methods to improve the survival of probiotics under different environmental conditions, technological approach to improving storage, and delivery along with possible negative consequences of using probiotics in aquaculture. A critical analysis of the identified challenges for the use of beneficial microbes in aquaculture will help in sustainable aquafarming, leading to improved agricultural practices with a clear aim to increase protein production.

Natural Polymers as Carriers for Encapsulation of Volatile Oils: Applications and Perspectives in Food Products

The technique of encapsulating different materials into matrices that can both protect and release their contents under specific circumstances is known as encapsulation. It serves the primary function of shielding delicate components from outside influences, including heat, light, and humidity. This can be accomplished by a variety of procedures that, depending on the method and materials selected, result in the creation of particles with various structures. The materials used for encapsulation in food applications must be of high quality, acceptable for human consumption, and stable during processing and storage. The most suitable natural polymers for food applications are carbohydrates, proteins, or mixtures thereof. Volatile oils are end products of plant metabolism, accumulated and stored in various plant organs, cells, or secretory tissues. These are natural and are characterized by the scent of the aromatic plants they come from. Because of their antibacterial and antioxidant qualities, they are being utilized more and more in the food and pharmaceutical industries. Since volatile oils are highly sensitive to environmental changes, they must be stored under specific conditions after being extracted from a variety of plant sources. A promising method for increasing the applicability of volatile oils is their encapsulation into colloidal particles by natural polymers such as carbohydrates and proteins. Encapsulation hides the unfavorable taste of nutrients while shielding delicate dietary ingredients from the effects of heat, moisture, oxygen, and pH. This technique results in improved stability for volatile oils that are often sensitive to environmental factors and offers the possibility of using them in an aqueous system even if they are insoluble in water. This paper aims to provide an overview of the current advances in volatile oil encapsulation technologies and presents a variety of natural polymers used in the food industry for encapsulation. Also, a distinct section is created to highlight the current advances in dairy products enriched with encapsulated volatile oils.

Boosting Enzyme Activity in Enzyme Metal-Organic Framework Composites

Enzymes, as highly efficient biocatalysts, excel in catalyzing diverse reactions with exceptional activity and selective properties under mild conditions. Nonetheless, their broad applications are hindered by their inherent fragility, including low thermal stability, limited pH tolerance, and sensitivity to organic solvents and denaturants. Encapsulating enzymes within metal-organic frameworks (MOFs) can protect them from denaturation in these harsh environments. However, this often leads to a compromised enzyme activity. In recent years, extensive research efforts have been dedicated to enhancing enzymatic activity within MOFs, leading to the development of new enzyme-MOF composites that not only preserve their catalytic potential but also outperform their free counterparts. This Review provides a comprehensive review on recent developments in enzyme-MOF composites with a specific emphasis on their enhanced enzymatic activity compared to free enzymes.

Electrochemical Acetylcholinesterase Sensors for Anti-Alzheimer's Disease Drug Determination

Neurodegenerative diseases and Alzheimer's disease (AD), as one of the most common causes of dementia, result in progressive losses of cholinergic neurons and a reduction in the presynaptic markers of the cholinergic system. These consequences can be compensated by the inhibition of acetylcholinesterase (AChE) followed by a decrease in the rate of acetylcholine hydrolysis. For this reason, anticholinesterase drugs with reversible inhibition effects are applied for the administration of neurodegenerative diseases. Their overdosage, variation in efficiency and recommendation of an individual daily dose require simple and reliable measurement devices capable of the assessment of the drug concentration in biological fluids and medications. In this review, the performance of electrochemical biosensors utilizing immobilized cholinesterases is considered to show their advantages and drawbacks in the determination of anticholinesterase drugs. In addition, common drugs applied in treating neurodegenerative diseases are briefly characterized. The immobilization of enzymes, nature of the signal recorded and its dependence on the transducer modification are considered and the analytical characteristics of appropriate biosensors are summarized for donepezil, huperzine A, rivastigmine, eserine and galantamine as common anti-dementia drugs. Finally, the prospects for the application of AChE-based biosensors in clinical practice are discussed.

Immobilization of α-amylase in calcium alginate-gum odina (CA-GO) beads: An easily recoverable and reusable support

A natural polysacharide, gum odina was collected from Odina wodier tree and purified. Purified gum odina was used with sodium alginate for immobilization of α-amylase. Calcium alginate-gum odina (CA-GO) beads were prepared by ionotropic gelation method to find the improvement of immobilization efficiency and reusability of α-amylase over calcium alginate (CA) beads. XRD, SEM, FTIR, beads diameter, enzyme leaching from beads, moisture content, total soluble matter and swelling study have been carried out to understand the physical morphology and mechanism of immobilization of enzyme in beads matrix. It has been observed that if the polymer ratio changes (keeping enzyme conc. & calcium Chloride conc. constant) then the size and shape of the beads will vary and at a particular range of polymer ratio, the optimal beads forms. At a certain conc.(4%w/v of SA and 1%w/v GO), the immobilization efficiency of CA-GO and CA beads were 92.71 ± 0.85 % (w/w) and 89.19 ± 0.35 %(w/w) respectively. After 8th time use, the CA-GO beads remain (~4 fold) more active than that of CA beads. The FTIR confirms that GO does not interfere with α-Amylase and alginate. Here, it can be concluded that CA-GO beads show better efficiency in respect to immobilization, reusability than CA beads only.

Recent Advances in Micro- and Nano-Drug Delivery Systems Based on Natural and Synthetic Biomaterials

Polymeric drug delivery technology, which allows for medicinal ingredients to enter a cell more easily, has advanced considerably in recent decades. Innovative medication delivery strategies use biodegradable and bio-reducible polymers, and progress in the field has been accelerated by future possible research applications. Natural polymers utilized in polymeric drug delivery systems include arginine, chitosan, dextrin, polysaccharides, poly(glycolic acid), poly(lactic acid), and hyaluronic acid. Additionally, poly(2-hydroxyethyl methacrylate), poly(N-isopropyl acrylamide), poly(ethylenimine), dendritic polymers, biodegradable polymers, and bioabsorbable polymers as well as biomimetic and bio-related polymeric systems and drug-free macromolecular therapies have been employed in polymeric drug delivery. Different synthetic and natural biomaterials are in the clinical phase to mitigate different diseases. Drug delivery methods using natural and synthetic polymers are becoming increasingly common in the pharmaceutical industry, with biocompatible and bio-related copolymers and dendrimers having helped cure cancer as drug delivery systems. This review discusses all the above components and how, by combining synthetic and biological approaches, micro- and nano-drug delivery systems can result in revolutionary polymeric drug and gene delivery devices.