An overview of additive manufacturing strategies of enzyme-immobilized nanomaterials with application incatalysis and biomedicine

Pota G., Andrés-Sanz D., Gallego M., Vitiello G., López-Gallego F., Costantini A., Califano V.

In this work, the adsorption of Candida antarctica B (CALB) and Rhizomucor miehei (RML) lipases into hydrophobic wrinkled silica nanoparticles (WSNs) is investigated. WSNs are hydrophobized by chemical vapor deposition. Both proteins are homogeneously distributed inside the pores of the nanoparticles, as confirmed by Transmission Electron Microscopy and Energy Dispersive X-ray measurements. The maximum enzyme load of CALB is twice that obtained for RML. Fourier Transform Infrared Spectroscopy confirms the preservation of the enzyme secondary structure after immobilization for both enzymes. Adsorption isotherms fit to a Langmuir model, resulting in a binding constant (KL) for RML 4.5-fold higher than that for CALB, indicating stronger binding for the former. Kinetic analysis reveals a positive correlation between enzyme load and RML activity unlike CALB where activity decreases along the enzyme load increases. Immobilization allows for enhancing the thermal stability of both lipases. Finally, CALB outperforms RML in the hydrolysis of ethyl-3-hydroxybutyrate. However, immobilized CALB yielded 20 % less 3-HBA than free lipase, while immobilized RML increases 3-fold the 3-HBA yield when compared with the free enzyme. The improved performance of immobilized RML can be explained due to the interfacial hyperactivation undergone by this lipase when immobilized on the superhydrophobic surface of WSNs.

Fahim Y.A., El-Khawaga A.M., Sallam R.M., Elsayed M.A., Assar M.F.

AbstractZinc ferrite nanoparticles (ZnF NPs) were synthesized by a green method using Psidium guava Leaves extract and characterized via structural and optical properties. The surface of ZnF NPs was stabilized with citric acid (CA) by a direct addition method to obtain (ZnF-CA NPs), and then lipase (LP) enzyme was immobilized on ZnF-CA NPs to obtain a modified ZnF-CA-LP nanocomposite (NCs). The prepared sample’s photocatalytic activity against Methylene blue dye (MB) was determined. The antioxidant activity of ZnF-CA-LP NCs was measured using 1,1-diphenyl-2-picryl hydrazyl (DPPH) as a source of free radicals. In addition, the antibacterial and antibiofilm capabilities of these substances were investigated by testing them against gram-positive Staphylococcus aureus (S. aureus ATCC 25923) and gram-negative Escherichia coli (E. coli ATCC 25922) bacterial strains. The synthesized ZnF NPs were discovered to be situated at the core of the material, as determined by XRD, HRTEM, and SEM investigations, while the CA and lipase enzymes were coated in this core. The ZnF-CA-LP NCs crystallite size was around 35.0 nm at the (311) plane. Results obtained suggested that 0.01 g of ZnF-CA-LP NCs achieved 96.0% removal of 5.0 ppm of MB at pH 9.0. In-vitro zone of inhibition (ZOI) and minimum inhibitory concentration (MIC) results verified that ZnF-CA-LP NCs exhibited its encouraged antimicrobial activity against S. aureus and E. coli (20.0 ± 0.512, and 27.0 ± 0.651 mm ZOI, respectively) & (1.25, and 0.625 μg/ml MIC, respectively). ZnF-CA-LP NPs showed antibiofilm percentage against S. aureus (88.4%) and E. coli (96.6%). Hence, ZnF-CA-LP NCs are promising for potential applications in environmental and biomedical uses.

Addai F.P., Wu J., Lin F., Ma X., Han J., Liu Y., Zhou Y., Wang Y.

Bilge S., Dogan-Topal B., Gürbüz M.M., Ozkan S.A., Sınağ A.

AbstractImproving novel and efficient biosensors for determining organic/inorganic compounds is a challenge in analytical chemistry for clinical diagnosis and research in biomedical sciences. Electrochemical enzyme-based biosensors are one of the commercially successful groups of biosensors that make them highly appealing because of their low cost, high selectivity, and sensitivity. Core/shell nanoparticles have emerged as versatile platforms for developing enzyme-based electrochemical biosensors due to their unique physicochemical properties and tunable surface characteristics. This study provides a comprehensive review of recent trends and advancements in the utilization of core/shell nanoparticles for the development of enzyme-based electrochemical biosensors. Moreover, a statistical evaluation of the studies carried out in this field between 2007 and 2023 is made according to the preferred electrochemical techniques. The recent applications of core/shell nanoparticles in enzyme-based electrochemical biosensors were summarized to quantify environmental pollutants, food contaminants, and clinical biomarkers. Additionally, the review highlights recent innovations and strategies to improve the performance of enzyme-based electrochemical biosensors using core/shell nanoparticles. These include the integration of nanomaterials with specific functions such as hydrophilic character, chemical and thermal stability, conductivity, biocompatibility, and catalytic activity, as well as the development of new hybrid nanostructures and multifunctional nanocomposites. Graphical Abstract

Cang Y., Yuan Y., Zhang K., Li X.L., Song T., Xie J.

C D., Jacob L., C M.S., Umer R., Butt H.

Vat photopolymerization (VP) 3D printing, a subset of additive manufacturing, is renowned for its capability to create intricate structures with high precision, particularly useful in optical applications. The process involves using photosensitive resins cured layer by layer through various light-curing technologies like Stereolithography (SLA), Digital Light Processing (DLP), Two-Photon Polymerization (TPP), Continuous Liquid Interface Production (CLIP), and Liquid Crystal Display (LCD). Each technique offers unique advantages in terms of speed, resolution, and material compatibility, with TPP providing the highest resolution. This review explores the diverse applications of VP 3D-printed optical components, including lenses, waveguides, optical gratings, resonators, metamaterials, sensors, and actuators, demonstrating their significant role in advancing optical technology and innovation. Challenges in material selection, post-processing requirements, size limitations, and support structures are discussed, alongside potential future research directions. These include developing advanced photopolymer materials with enhanced optical properties, hardware improvements for higher resolution and multi-material printing, and quality assurance measures for ensuring optical precision. Despite some limitations, VP 3D printing presents a promising avenue for the rapid prototyping and production of complex, multifunctional optical devices, marking a significant stride in optical manufacturing and technological development.

Melo R.L., Freire T.M., Valério R.B., Neto F.S., de Castro Bizerra V., Fernandes B.C., de Sousa Junior P.G., da Fonseca A.M., Soares J.M., Fechine P.B., dos Santos J.C.

Magnetic nanoparticles were functionalized with polyethylenimine (PEI) and activated with epoxy. This support was used to immobilize Lipase (Eversa® Transform 2.0) (EVS), optimization using the Taguchi method. XRF, SEM, TEM, XRD, FTIR, TGA, and VSM performed the characterizations. The optimal conditions were immobilization yield (I.Y.) of 95.04 ± 0.79 %, time of 15 h, ionic load of 95 mM, protein load of 5 mg/g, and temperature of 25 °C. The maximum loading capacity was 25 mg/g, and its stability in 60 days of storage showed a negligible loss of only 9.53 % of its activity. The biocatalyst demonstrated better stability at varying temperatures than free EVS, maintaining 28 % of its activity at 70 °C. It was feasible to esterify free fatty acids (FFA) from babassu oil with the best reaction of 97.91 % and ten cycles having an efficiency above 50 %. The esterification of produced biolubricant was confirmed by NMR, and it displayed kinematic viscosity and density of 6.052 mm2/s and 0.832 g/cm3, respectively, at 40 °C. The in-silico study showed a binding affinity of -5.8 kcal/mol between EVS and oleic acid, suggesting a stable substrate-lipase combination suitable for esterification.

Caetano K.D., Lieberknecht G., Benvenutti E.V., Pereira M.B., Hinrichs R., Hertz P.F., Rodrigues R.C., de Menezes E.W., Arenas L.T., Costa T.M.

A novel electrochemical sensing platform was created using the formation of a sequence of films, over a conductive fluorine-doped tin oxide glass (FTO), obtained using the sol-gel method and the dip coating technique. Firstly, thin films of silica-zirconia mixed oxides were deposited, in sequence an ionic silsesquioxane film stabilizing and controlling the size of gold nanoparticles (6.5 ± 2.4 nm) was settled, and after the lipase enzyme, obtained from Candida rugosa, was entrapped into a silica film maintaining its operational stability. The films were characterized by scanning electron microscopy (SEM) with EDX, UV–Vis spectroscopy and X-ray photoelectron spectroscopy (XPS). The thickness of each film on the FTO glass was evaluated by optical profilometry. The presence of the enzyme on the platform was confirmed by cyclic voltammetry with the ρ-nitrophenyl palmitate method. This platform was applied successfully as a biosensor for tributyrin (TB) determination by electrochemical impedance spectroscopy EIS, showing low limit of detection (LD) of 1.86 μmol L−1 and high sensitivity of 5.37 μΩ μmol−1 L. The biosensor presented a low KMapp value of 22.69 μmol L − 1 and the Vmaxapp value of 85.57 μmol L−1 min−1 suggesting that the enzyme, immobilized with this method retained activity promoting a fast enzymatic reaction with the TB.

Núñez-Serrano A., García-Reyes R.B., Solís-Pereira S., García-González A.

Global market of food enzymes is held by pectinases, mostly sourced from filamentous fungi via submerged fermentation. Given the one-time use nature of enzymes to clarify juices and wines, there is a crucial need to explore alternatives for enzyme immobilization, enabling their reuse in food applications. In this research, an isolated fungal strain (Penicillium crustosum OR889307) was evaluated as a new potential pectinase producer in submerged fermentation. Additionally, the enzyme was immobilized in magnetic core-shell nanostructures for juice clarification. Findings revealed that Penicillium crustosum exhibited enzymatic activities higher than other Penicillium species, and pectinase production was enhanced with lemon peel as a cosubstrate in submerged fermentation. The enzyme production (548.93 U/mL) was optimized by response surface methodology, determining the optimal conditions at 35 °C and pH 6.0. Subsequently, the enzyme was covalently immobilized on synthesized magnetic core-shell nanoparticles. The immobilized enzyme exhibited superior stability at higher temperatures (50 °C) and acidic conditions (pH 4.5). Finally, the immobilized pectinases decreased 30 % the orange juice turbidity and maintained 84 % of the enzymatic activity after five consecutive cycles. In conclusion, Penicillium crustosum is a proven pectinase producer and these enzymes immobilized on functionalized nanoparticles improve the stability and reusability of pectinase for juice clarification.

Sánchez-Morán H., Kaar J.L., Schwartz D.K.

AbstractDesigning complex synthetic materials for enzyme immobilization could unlock the utility of biocatalysis in extreme environments. Inspired by biology, we investigate the use of random copolymer brushes as dynamic immobilization supports that enable supra-biological catalytic performance of immobilized enzymes. This is demonstrated by immobilizing Bacillus subtilis Lipase A on brushes doped with aromatic moieties, which can interact with the lipase through multiple non-covalent interactions. Incorporation of aromatic groups leads to a 50 °C increase in the optimal temperature of lipase, as well as a 50-fold enhancement in enzyme activity. Single-molecule FRET studies reveal that these supports act as biomimetic chaperones by promoting enzyme refolding and stabilizing the enzyme’s folded and catalytically active state. This effect is diminished when aromatic residues are mutated out, suggesting the importance of π-stacking and π-cation interactions for stabilization. Our results underscore how unexplored enzyme-support interactions may enable uncharted opportunities for using enzymes in industrial biotransformations.

Zhang J., Lovell J.F., Shi J., Zhang Y.

AbstractIn order to co‐immobilize multiple enzymes, a wide range of nanomaterials has been designed to achieve synergistic enzyme activity and enhance catalytic efficiency. Nanomaterials, as carriers for enzyme co‐immobilization, possess various advantages such as tunable morphology and size, high specific surface area, and abundant chemically active sites. They can significantly enhance enzyme stability, activity, and catalytic efficiency. We overview the commonly used methods and strategies of enzyme co‐immobilization. This review further summarizes the latest research advances in nanomaterials for enzyme co‐immobilization applications over the past 5 years. Meanwhile, the advantages and challenges of these nanomaterials used for enzyme co‐immobilization as well as some potential future directions are also discussed.

Manoj Kumar C.T., Supreetha S., Sathish Kumar M.H., Laxmana Naik N., Jayaraj Rao K.

The β-galactosidase (produced from Aspergillus oryzae) was immobilised on epichlorohydrin functionalised mesoporous silicon dioxide nanoparticles to produce galactooligosaccharides (GOS) from lactose. The characteristic amide bonds and increased particle size confirmed the adsorption of enzyme on nanoparticles. Nano-immobilisation resulted in an increase in enzyme affinity towards the substrate and its hydrolytic property. Free and nano-immobilised enzymes retained 58 and 77% of the original enzyme activity up to 90 days of storage, respectively. The nano-immobilised enzyme exhibited greater stability over a broad range of temperature (30–70 °C) and pH (5.0–8.0). The GOS yield obtained from nano-immobilised enzyme was 2.23 times higher than the free enzyme. GOS production was decreased by 90% and enzyme activity was reduced to 10% in a run of 5 cycles. Overall, the developed nano-immobilisation technique has potential to enhance the stability of the enzyme and GOS production.

O’Connell A., Barry A., Burke A.J., Hutton A.E., Bell E.L., Green A.P., O’Reilly E.

This tutorial review will give readers an insight into the landmark discoveries and milestones that have helped shape and grow the field of biocatalysis since the discovery of the first enzyme.

Xing S., Long J., Xie W., Luo C., He L., Li C., Zeng X.

Abstract Enzyme immobilized on magnetic nanomaterials is a promising biocatalyst with efficient recovery under applied magnets. In this study, a recombinant extracellular lipase from Aspergillus niger GZUF36 (PEXANL1) expressed in Pichia pastoris GS115 was immobilized on ionic liquid-modified magnetic nano ferric oxide (Fe3O4@SiO2@ILs) via electrostatic and hydrophobic interaction. The morphology, structure, and properties of Fe3O4@SiO2@ILs and immobilized PEXANL1 were characterized by scanning electron microscopy, Fourier transform infrared spectroscopy, x-ray diffraction, vibration sample magnetometer, and zeta potential analysis. Under optimized conditions, the immobilization efficiency and activity recovery of immobilized PEXANL1 were 52 ± 2% and 122 ± 2%, respectively. The enzymatic properties of immobilized PEXANL1 were also investigated. The results showed that immobilized PEXANL1 achieved the maximum activity at pH 5.0 and 45 °C, and the lipolytic activity of immobilized PEXANL1 was more than twice that of PEXANL1. Compared to PEXANL1, immobilized PEXANL1 exhibited enhanced tolerance to temperature, metal ions, surfactants, and organic solvents. The operation stability experiments revealed that immobilized PEXANL1 maintained 86 ± 3% of its activity after 6 reaction cycles. The enhanced catalytic performance in enzyme immobilization on Fe3O4@SiO2@ILs made nanobiocatalysts a compelling choice for bio-industrial applications. Furthermore, Fe3O4@SiO2@ILs could also benefit various industrial enzymes and their practical uses. Key points • Immobilized PEXANL1 was confirmed by SEM, FT-IR, and XRD. • The specific activity of immobilized PEXANL1 was more than twice that of PEXANL1. • Immobilized PEXANL1 had improved properties with good operational stability. Graphical abstract

Ansari M.A., Mohd-Naim N.F., Ahmed M.U.