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In this work hyper-branched poly (amide amine) (PAMAM) nanoparticles were conjugated with hyaluronidase (Hyal) to produce a robust nano-biocatalyst for hyaluronic acid (HA) degradation. The success enzyme attachment process was confirmed by Fourier transform infrared (FTIR), transmission electron microscopy (TEM), dynamic light scattering (DLS), and UV-Vis. The influence of pH, temperature, and inhibitor on the enzymatic activity of hyaluronidase was also investigated. The optimum pH, temperature and storage time of Hyal-PAMAM nanocomplex were higher than free enzyme. Also, ascorbic acid showed more inhibitory effect on free enzyme, the IC50 values were determined to be around 55±0.7 and 70±0.3 mM for free Hyal and Hyal-PAMAM nanocomplex, respectively. Based on the greater υmax and lower Km, the Hyal-PAMAM showed a better catalytic efficiency for HA degradation. Moreover, the in silico screening of PAMAM/Hyal interactions further confirmed the experimental results. The novel strategy for combining Hyal and PAMAM dendrimer can hold great promise for applications in biomedical, sensing, and industrial catalysis.

The global health status is highly affected by the growing pace of urbanization, new lifestyles, climate changes, and resource exploitation. Modern technologies pave a promising way to deal with severe concerns toward sustainable development. Herein, we provided a comprehensive review of some popular biotechnological advancements regarding the progress achieved in water, food, and medicine, as the most substantial fields related to public health. The emergence of novel organic/inorganic materials has brought about significant improvement in conventional water treatment techniques, anti-fouling approaches, anti-microbial agents, food processing, biosensors, drug delivery systems, and implants. Particularly, a growing interest has been devoted to nanomaterials and their application for developing novel structures or improving the characteristics of standard components. Also, bioinspired materials have been widely used to improve the performance, efficiency, accuracy, stability, safety, and cost-effectiveness of traditional systems. On the other side, the fabrication of innovative devices for precisely monitoring and managing various ecosystem and human health issues is of great importance. Above all, exceptional advancements in designing ion-selective electrodes (ISEs), microelectromechanical systems (MEMs), and implantable medical devices have altered the future landscape of environmental and biomedical research. This review paper aimed to shed light on the wide-ranging materials and devices that have been developed for health applications and mainly focused on the impact of nanotechnology in this field.

The demand for food and beverage markets has increased as a result of population increase and in view of health awareness. The quality of products from food processing industry has to be improved economically by incorporating greener methodologies that enhances the safety and shelf life via the enzymes application while maintaining the essential nutritional qualities. The utilization of enzymes is rendered more favorable in industrial practices via the modification of their characteristics as attested by studies on enzyme immobilization pertaining to different stages of food and beverage processing; these studies have enhanced the catalytic activity, stability of enzymes and lowered the overall cost. However, the harsh conditions of industrial processes continue to increase the propensity of enzyme destabilization thus shortening their industrial lifespan namely enzyme leaching, recoverability, uncontrollable orientation and the lack of a general procedure. Innovative studies have strived to provide new tools and materials for the development of systems offering new possibilities for industrial applications of enzymes. Herein, an effort has been made to present up-to-date developments on enzyme immobilization and current challenges in the food and beverage industries in terms of enhancing the enzyme stability.

The covalent immobilization of xylanase onto the trichlorotriazine-functionalized polyethylene glycol grafted magnetic nanoparticles was exploited to generate a stabilized xylanase with improved catalytic activity and stability. Several tools were deployed to monitor the synthesis and immobilization processes, the loading capacity of nanocarrier, and the structural/chemical characteristics of the nanobiocatalyst. The optimum immobilization yield of xylanase was 260 mg xylanase/g nanocarrier in 20 mM phosphate buffer, pH 6.5 at 25 °C. A forward shift in optimum pH (6.5 to 7.5) and temperature (60 to 70 °C) of xylanase was observed after immobilization and the performance of immobilized enzyme was improved at high temperatures and pHs as affirmed by enhancement of vmax (2.69 to 6.01 U/mL) and decreases of Ea (14.61 to 13.41 kJ/mol). An increase in Km from 25.51 to 40.42 mg/mL was recorded after immobilization. The obtained results indicated augmented thermal stability of the immobilized xylanase. Notably, it showed good reusability as validated by retention of 50% of its initial activity after nine recycles in enrichment of the pineapple juice clarification after 120 min incubation at 50 °C, pH 4.5. The structural analysis revealed some partial changes in the α-helix and β-sheet content of the enzyme after several recycles.

Developing an effective strategy to economically exploitation of pectinase, as one of the most widely used enzymes in food industry, is of utmost importance. Herein, pectinase was covalently immobilized onto polyethylene glycol grafted magnetic nanoparticles via trichlorotriazine with high loading efficiency. The generated immobilized pectinase showed enhanced catalytic activity, improved operational stability, and easily reusability. Thermal and pH stabilities studies showed improved performance of immobilized pectinase especially at extreme points. Compared to free enzyme, the noticeably lower Km and higher vmax values of immobilized pectinase demonstrated the enhanced catalytic activity of this enzyme after immobilization. Besides, the immobilized enzyme exhibited excellent reusability and stability by retaining up to 55 and 94% of its initial activity after 10 recycles and 125 days storage at 25 °C, respectively. Moreover, turbidity reduction occurred up to 59% in treated pineapple juice with immobilized pectinase, suggesting applicability of this system in juice and food-processing industries.

1,3,5-Triazine-functionalized silica encapsulated magnetic nanoparticles (MNPs) have been successfully synthesized. The morphology, structure and properties of functionalized nanoparticles were investigated through different analytical tools including Fourier transform infrared spectroscopy, scanning electron microscopy, transmission electron microscopy, and X-ray powder diffraction. Due to the magnetic nature and the presence of triazine functionalized groups, the as-prepared Fe3O4@SiO2 nanoparticles were employed as magnetic carriers for xylanase immobilization. The xylanase immobilized on functionalized MNPs (Xy-MNP) exhibited excellent catalytic activity at pH 6.5 and 65 °C. Notably, Xy-MNPs had significant effect on juice clarity and showed quite impressive stability, even after 10 reaction cycles in the enrichment of the juices clarification, it could still retain about 55% of the initial activity. The Xy-MNPs illustrated similar clarity enrichment for three types of fruit juices, after 5 h incubation at 50 °C. The effect of metal ions and organic solvents on the activity of immobilized xylanase was investigated. The results showed an increasing in the catalytic activity of Xy-MNPs in the presence of some metal ions while they have inhibitory effect on the activity of free xylanase. Also both free and immobilized xylanase were inhibited in the presence of 50% (v/v) organic solvents, whereas the Xy-MNPs activity was significantly increased in the presence of 10% (v/v) organic solvents. It is hoped that the 1,3,5-triazine-functionalized Fe3O4@SiO2 nanoparticles may find an application in modern biotechnology.

Enzymes are used as biocatalysts for analytical purposes in diagnostics and preparative purposes in large-scale industrial processes. Despite perfect catalytic properties of enzymes, their industrial applications are limited due to the drawbacks regarding the lack of long-term stability under process conditions. The difficulties associated with recycling have to be resolved before enzyme implementation at industrial scale. Enzyme immobilization, as a novel approach, can improve the half-life, stability, catalytic activity, and reusability of enzymes. Graphene-based nanomaterials, as nanoscaled and thermostable inorganic carriers, are nontoxic materials and selective modulators for enzyme activity. Herein, we have concentrated on strategies for preparing graphene-based nanocomposites for enzyme immobilization. Nanostructures of graphene, hybrid graphene, and their derivatives with adjustable surface chemistry, caused them to be excellent candidates for immobilization of enzymes. For instance, the synthesis and functionalization of Fe

In industrial processes, effective degradation of polygalacturonic acid using immobilized pectinase is preferred over free one due to its stability and efficient functional reuses. Pectinase was covalently conjugated to the surface of cyanuric chloride functionalized chitosan encapsulated magnetite nanoparticles. The results obtained of various analytical tools and biochemical studies demonstrated successful synthesis and immobilization processes, high immobilization efficiency and loading capacity. The circular dichroism (CD) results of free and immobilized pectinase revealed the partial decreases in the α-helices and β-sheets, and marginal increases in the unordered elements contents of pectinase upon the immobilization onto Fe3O4@Ch-CC nanoparticles, along with stability improvement. The immobilized pectinase was retained about 60% of its initial catalytic activity after 13 recycles at optimum conditions (40 °C, pH 4.5). The storage stability of pectinase was increased due to immobilization, after 75 days storage at 4 °C, the free and immobilized enzyme retained 43% and 74% of the initial activity, respectively. The immobilized pectinase showed higher storage stability and better performance at wider ranges of pH and temperature, compared to free pectinase.

The covalent binding of xylanase to silica-coated modified magnetite nanoparticles via cyanuric chloride activation was investigated. The structure, size, and magnetic properties of the support and immobilized xylanase were characterized by transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), Fourier-transform infrared spectra (FTIR), thermo-gravimetric analysis (TGA) and vibrating sample magnetometer (VSM) analysis. The TEM images showed that the xylanase immobilized on functionalized magnetic nanoparticles (xylanase-MNPs) possessed three dimensional core–shell structures with an average diameter of ∼9 nm. The FTIR and XPS results demonstrated the successful immobilization of xylanase on functionalized MNPs. Results from Bradford protein assay and TGA indicated that xylanase was covalently attached to the surface of modified magnetic nanoparticles with immobilization yield of 280 mg enzyme/g MNPs. The VSM analysis revealed that Fe 3 O 4 , Fe 3 O 4 @SiO 2 and xylanase-MNPs had high saturation magnetization of 69.4, 63.84 and 46.56 emu/g, respectively. Enzymatic activity, reusability, thermo-stability, pH-stability, and storage stability of the immobilized xylanase were found significantly superior to those of the free one. The xylanase-MNPs exhibited maximal catalytic activity at pH 6.5 and 60 °C and the immobilized enzymes were found to keep as high as 80% of the activity of free ones. Notably, xylanase-MNPs showed quite impressive stability, even after 9 reaction cycles, it could still retain about 65% of the initial activity. The measurement of Michaelis–Menten parameters ( K m and v max ) also revealed the considerable improvement of immobilized enzyme. The results suggested that xylanase-MNPs could be used in an interesting range of application allowing both using in broader temperature and pH ranges, facilitating long-term storage, while permitting magnetic recovery of the enzyme for reuse or purification of the product.

Enzymes are used as biocatalysts for analytical purposes in diagnostics and preparative purposes in large-scale industrial processes. Despite perfect catalytic properties of enzymes, their industrial applications are limited due to the drawbacks regarding the lack of long-term stability under process conditions. The difficulties associated with recycling have to be resolved before enzyme implementation at industrial scale. Enzyme immobilization, as a novel approach, can improve the half-life, stability, catalytic activity, and reusability of enzymes. Graphene-based nanomaterials, as nanoscaled and thermostable inorganic carriers, are nontoxic materials and selective modulators for enzyme activity. Herein, we have concentrated on strategies for preparing graphene-based nanocomposites for enzyme immobilization. Nanostructures of graphene, hybrid graphene, and their derivatives with adjustable surface chemistry, caused them to be excellent candidates for immobilization of enzymes. For instance, the synthesis and functionalization of Fe3O4-graphene oxide (GO) hybrids were improved recently, in our research group, using cyanuric chloride and polyethylene glycol bis-amine for the immobilization of xylanase and glucoamylase enzymes, via physical and covalent attachments. Decorating GO nanosheets with Fe3O4 nanoparticles has facilitated the reusability of enzymes and increased the surface area for enzyme loading. The use of these hydrophilic crosslinkers may change the microenvironment of the immobilized enzymes that could result in the enhancement of their catalytic activity. As a result of the fascinating properties of graphene-based nanocarriers, with respect to structures that can be oriented and surfaces that can be modified, in our opinion, they offer some important advantages for biotechnological applications, especially in the areas of enzyme immobilization and medicine.

Aspergillus niger glucoamylase (GLA) was covalently immobilized on 1,3,5-triazine-functionalized chitosan coated superparamagnetic nanoparticles (MNPCh-CC). The morphology, structure and properties of functionalized nanocomposite were investigated, as well as GLA immobilization process, through different analytical tools. Different experimental parameters such as optimum temperature, pH, reaction time and enzyme concentration were studied for free and immobilized enzyme. The GLA immobilized on nanocarrier exhibited excellent catalytic activity at pH 4.5 and 60 °C. Notably, the immobilized GLA showed quite impressive stability, even after 10 reaction cycles, it could still retain about 70% of the initial activity. The results showed that immobilization process couldn’t significantly inhibit enzyme-substrate interaction and subsequently retained its effective catalytic activity. The substantial improvement of reactivity, reusability, and stability of this biocatalyst system may confer it a wider range of applications in industrial processes.

Although several strategies are now available for immobilization of enzymes to magnetic nanoparticles for bioapplications, little progresses have been reported on the use of dendritic or hyperbranched polymers for the same purpose. Herein, we demonstrated synthesis of magnetic nanoparticles supported hyperbranched polyglycerol (MNP/HPG) and a derivative conjugated with citric acid (MNP/HPG-CA) as unique and convenient nanoplatforms for immobilization of enzymes. Then, an important industrial enzyme, xylanase, was immobilized on the nanocarriers to produce robust biocatalysts. A variety of analytical tools were used to study the morphological, structural, and chemical properties of the biocatalysts. Additionally, the results of biocatalyst systems exhibited the substantial improvement of reactivity, reusability, and stability of xylanase due to this strategy, which might confer them a wider range of applications.