Immobilization of l-asparaginase on chitosan nanoparticles for the purpose of long-term application

Structures and properties of α-amylase and glucoamylase immobilized by ZIF-8 via one-pot preparation

The immobilization of α-amylase and glucoamylase using a metal-organic framework (enzyme@ZIF-8) was prepared in situ through a one-pot method. The morphology, crystal structure, and molecular characteristics of the free enzyme and enzyme@ZIF-8 were characterized. The enzyme@ZIF-8 exhibited the rhombic dodecahedron morphology, with a decrease in particle size. Successful immobilization of α-amylase and glucoamylase within ZIF-8 was confirmed, with 30-40 % loading rate. The immobilization process did not significantly alter the crystal structure of ZIF-8. The changes in secondary structure of enzyme after immobilization resulted in modification of catalytic activity of enzyme. The melting enthalpy of enzyme @ZIF-8 increased with the increase of enzyme content. The melting peak temperature of the enzyme immobilized by ZIF-8 increased. The activity of free and immobilized enzymes was influenced by the different time, pH and temperature. At pH 5-8 and temperature 60-80 °C, the activity of the immobilized enzyme was significantly greater than that of the free enzyme. The repeatability of enzyme@ZIF-8 was 61.52 % after three cycles. The kinetic parameters of Michaelis-Menten model for enzymatic reaction were determined by fitting the initial rate of reactions and initial substrate concentration data. The Michaelis-Menten constant (KM) values of immobilized enzyme were lower than that of free enzyme, indicating the greater affinity between the enzyme and the substrate.

Sodium tripolyphosphate is a non-toxic and economic alternative to glutaraldehyde for preparation of L-asparaginase CLEAs to reduce acrylamide in potato fries

L-Asparaginase CLEAs were prepared utilizing sodium tripolyphosphate (TPP) as a crosslinker (TA-CLEA). Under optimized conditions (pH 3, 0.3% TPP concentration, and a crosslinking time of 1 h), an 85% activity recovery was achieved. TA-CLEAs demonstrated superior pH stability (pH 3-8) compared to GA (glutaraldehyde)-CLEA but lost structural integrity at pH 9. TA-CLEAs were thermally more stable (concerning activity) and structurally less stable than GA-CLEA owing to the presence of weaker ionic bonds. TA-CLEAs reported an increase in apparent Km (reduced substrate affinity) and apparent Vmax values and displayed excellent reusability after 10 cycles of use (> 75%). The increase in β-sheet and random coil structures indicated a trade-off between structure stability and flexibility of the protein. TA-CLEAs reduced the acrylamide content in potato fries by 79% after 40 min of treatment time. Thus, the use of TPP as a non-toxic, economical, and biocompatible alternative to the conventionally used toxic crosslinker glutaraldehyde was demonstrated.

l-Asparaginase Immobilized on Nanographene Oxide as an Efficient Nanobiocatalytic Tool for Asparagine Depletion in Leukemia Cells

l-Asparaginase (l-ASNase) catalyzes the hydrolysis of l-asparagine, leading to its depletion and subsequent effects on the cellular proliferation and survival. In contrast to normal cells, malignant cells that lack asparagine synthase are extremely susceptible to asparagine deficiency. l-ASNase has been successfully employed in treating pediatric leukemias and non-Hodgkin lymphomas; however, its usage in adult patients and other types of cancer is limited due to significant side effects and drug resistance. Recent research has explored alternative formulations and delivery methods to enhance its efficacy and minimize adverse effects. One promising approach involves the immobilization of l-ASNase onto nanostructured materials, offering improved enzymatic activity and biocompatibility of the support. We harnessed an E. coli l-ASNase type II preparation to develop a novel strategy of enzyme immobilization on graphene oxide (GO)-based support. We compared GO and nanographene oxide (nGO) in terms of their biocompatibility and influence on enzyme parameters. The obtained l-ASNase on the nGO nanobiocatalyst maintains enzymatic activity and increases its stability, selectively acting on K562 leukemia cells without cytotoxic influence on normal endothelial cells. In the case of treated K562 cells, we confirmed enlargement in the cell and nucleus size, disturbance in the cell cycle (interphase and metaphase), and increased apoptosis rate. The potential therapeutic possibilities of immobilized l-ASNase on leukemia cell damage are also discussed, highlighting the importance of further research in this area for advancing cancer therapy.

Comparing the effectiveness of curcumin and papain in wound dresses based on chitosan nanoparticle

In this study, chitosan/curcumin (CS/Cur) and chitosan/papain (CS/Pa) nanoparticles were prepared and then characterized by Fourier transform infrared (FTIR), X-ray diffraction (XRD), and differential light scattering (DLS). Subsequently, release rate, porosity, swelling, degradability, anti-inflammatory, antioxidant, antibacterial, and cell viability tests were conducted to investigate and compare the healing potential of the nanoparticles for various types of wounds. The results of FTIR, XRD, and DLS indicated that the nanoparticles were manufactured correctly with a hydrodynamic diameter of 429 nm (CS/Cur) and 460 nm (CS/Pa), and zeta potential of 4.32 mV (CS/Cur) and 7.57 mV (CS/Pa). The release rate results indicated a higher release rate in a basic environment (pH 8.4) for curcumin, a higher release rate for papain in an acidic environment (pH 6.4), and the Korsmeyer-Peppas model for the release of curcumin and papain. The results indicated that CS/Cur with 41.6% antioxidant activity, high antibacterial effect, and cell growth up to 616% during 7 days, was more effective than CS/Pa. In comparison, CS/Pa (with a porosity of 70.5% and a swelling rate of 1392%) was more advantageous than CS/Cur in terms of porosity and swelling. In addition, CS/Cur was as effective as CS/Pa in terms of degradation and anti-inflammatory properties. In conclusion, the outcomes represented that the CS/Cur and CS/Pa nanoparticles improved wound healing, and each was suitable for specific wounds and wound healing stages.

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

Meticulous and bespoke fabrication of structural materials with simple yet innovative outlines along with on-demand availability is the imperative aspiration for numerous fields. The alliance between nanotechnology and enzymes has led to the establishment of an inimitable and proficient class of materials. With the advancement in the field of additive manufacturing, the fabrication of some complex biological architects is achievable with similitude to the instinctive microenvironment of the biological tissue. Rendering these enzymes-linked nanomaterials through 3D printing for biosensing, catalytic, and biomedical applications is challenging due to the need for a precise controlled, regulated system with scaleup capability for commercialization. The current review highlights the importance of nanomaterials as a persuasive matrix for enzyme immobilization along with the key parameters that regulate the rate of immobilization and the activity of the concerned enzyme. Precise attention has been devoted to the different strategies for immobilizing enzymes in the nanomaterial's matrix. The present review offers a comprehensive discussion on the utility of 3D printing technology for enzyme-immobilized nanomaterials in biosensing, catalysis, and biomedical applications. The employment of 3D printing grants new developments and avenues in the vast field of enzyme- immobilized nanomaterials.

Enhancing the Stability and Anticancer Activity of Escherichia coli Asparaginase Through Nanoparticle Immobilization: A Biotechnological Perspective on Nano Chitosan

There is a shortage in the experimental research directly comparing the effectiveness of different nanoparticles in boosting asparaginase (ASNase) activity. This study assessed the impact of various nanoparticles on enhancing ASNase activity, stability, and anticancer effects through immobilization. Escherichia coli ASNase was immobilized on different nanoparticles, and its efficiency was measured. The research included analyzing the enzyme's secondary structure, stability, activity at different temperatures, kinetic parameters, shelf life, and activity in blood serum. The anticancer efficacy was determined by measuring the IC50. The study also investigated the anticancer mechanisms by examining the enzyme's toxicity on cancer cells, focusing on apoptosis indicators like nuclear intensity, membrane permeability, mitochondrial membrane permeability, and cytochrome c release. Among the tested nanoparticles, nano chitosan yielded the best improvements. ASNase immobilized on nano chitosan reached 90% immobilization efficiency fastest among the studied nanoparticles, achieving this within 72 h, whereas other nanoparticles took 120 h. Immobilization modified ASNase's secondary structure by increasing alpha helices and reducing random coils, with nanochitosan and magnetic iron oxide showing the most pronounced effects. Immobilized ASNase exhibited enhanced activity, stability across temperature (widest with nanochitosan, 25-65 °C), and a broader optimal pH range compared to the free enzyme, with a Km of 1.227 mM and a Vmax of 454.54 U/mg protein. Notably, the nano-chitosan-immobilized ASNase retained over 85% of its activity after 9 months of storage and maintained high activity in blood serum. This improved stability and activity translated into the highest anticancer activity (Lowest IC50) and was more effective than doxorubicin in disrupting cancer cell structures.

Immobilization of L-Asparaginase on biofunctionalized magnetic graphene oxide nanocomposite: A promising approach for Enhanced Stability and reusability

The application of the amidohydrolase enzyme, L-asparaginase (ASNase), as a biocatalyst in the food and pharmaceutical industries has garnered significant interest. However, challenges such as hypersensitivity reactions, limited stability, and reusability under various operational conditions have hindered its cost-effective utilization. This paper introduces a novel nano-support for ASNase immobilization, namely the nanocomposite of iron oxide magnetic nanoparticles and amino acid-decorated graphene oxide (GO-Asp-Fe3O4). Characterization using FTIR spectroscopy, FE-SEM, and TEM microscopy revealed the homogeneous distribution of iron oxide nanoparticles on the surface of GO sheets. The effects of carrier functionalization and carrier-to-protein ratio on the immobilization of ASNase were studied to optimize the immobilization conditions. The magnetized nanocomposite of ASNase exhibited a 4.4-fold lower Michaelis-Menten constant (Km), suggesting an enhanced affinity for the substrate. The immobilized ASNase demonstrated two to eight times higher thermostability compared to the free enzyme and showed an extremely extended pH stability range. Furthermore, the immobilized enzyme retained over 80 % of its initial bioactivity after eight repeated reaction cycles. These findings suggest that the immobilization of ASNase on GO-Asp- Fe3O4 nanocomposite could be a viable option for industrial applications.

Immobilization of l-asparaginase on genipin cross-linked chitosan beads shows better acrylamide diminution in cassava chips: Process optimization and characterization

Glutaraldehyde is the conventionally used cross-linker for the activation and cross-linking of support matrices used in enzyme immobilization. However, the toxic nature of glutaraldehyde makes it unsafe for food applications, propelling the need for nontoxic cross-linkers. Genipin reacts with the primary and secondary amines generating a dark-blue colored pigment and is an attractive alternative to glutaraldehyde as a cross-linker for enzyme immobilization. Apart from its excellent cross-linking properties, genipin possesses added advantages over glutaraldehyde such as proven health benefits, biocompatibility, and biodegradability. The present study explores the application of chitosan beads cross-linked with the natural and nontoxic agent, genipin, for immobilizing l-asparaginase, aimed at its subsequent use in mitigating acrylamide formation in food products. The immobilized l-asparaginase exhibited improved functionalities such as stability, reusability, and reduction in acrylamide formation in deep-fried cassava chips. One of the limitations observed during application in the food process was the mechanical fragility of the chitosan beads during speedy stirring. This can be overcome by increasing the concentration and time of contact of the coagulant bath during the formation of chitosan beads. The drying of the enzyme-bound chitosan beads will also lead to shrinkage and prevent breakage during stirring. This study conclusively demonstrated the applicability of immobilizing l-asparaginase on genipin cross-linked chitosan beads in food-related processes.

In vitro and in silico analysis unravelled clinically desirable attributes of Bacillus altitudinis L-asparaginase

AIMS

To identify a marine L-asparaginase with clinically desirable attributes and characterize the shortlisted candidate through in silico tools.

METHODS AND RESULTS

Marine bacterial strains (number = 105) isolated from marine crabs were evaluated through a stepwise strategy incorporating the crucial attributes for therapeutic safety. The results demonstrated the potential of eight bacterial species for extracellular L-asparaginase production. However, only one isolate (Bacillus altitudinis CMFRI/Bal-2) showed clinically desirable attributes, viz. extracellular production, type-II nature, lack of concurrent L-glutaminase and urease activities, and presence of ansZ (functional gene for clinical type). The enzyme production was 22.55 ± 0.5 µM/mg protein/min within 24 h without optimization. The enzyme also showed good activity and stability in pH 7-8 and temperature 37°C, predicting the functioning inside the human body. The Michealis-Menten constant (Km) was 14.75 µM. Detailed in silico analysis based on functional gene authenticating the results of in vitro characterization and predicted the nonallergenic characteristic of the candidate. Docking results proved the higher affinity of the shortlisted candidate to L-asparagine than L-glutamine and urea.

CONCLUSION

Comprehensively, the study highlighted B. altitudinis type II asparaginase as a competent candidate for further research on clinically safe asparaginases.