ABSTRACT
Background: Enzyme engineering by immobilization techniques has proven to be well compatible with the other chemical or biological approaches aiming to improve enzyme's functions and stability. Zeolites are porous alumino-silicates with a wide range of porosity and particle size along with the other remarkable properties such as high surface area, high stability against a wide range temperatures, pHs, as well as organic solvents
Objectives: Nano-zeolites are a class of advanced materials that have special properties that has made them ideal candidate for a wide range of applications
Materials and Methods: In this study, a nano-zeolite which has been synthesized and characterized in our previous work, was used to immobilize alpha-amylase and activated with glutaraldehyde as a bi-functional agent to improve enzyme properties
Results: Studies have shown an increased stability of the immobilized enzyme compared to the free enzyme against a range of temperature change and pHs as well. Also the stability of the immobilized enzyme was increased with respect to storage. The calculated binding efficiency shows that the immobilized alpha-amylase conserved 58.44% of its native activity
Conclusions: Using nano pore zeolite for covalent attachment of the alpha-amylase resulted in an increased resistance of this enzyme against denaturation. The immobilized enzyme demonstrated higher stability compared to the free enzyme at higher temperatures and pH variations. Immobilization also caused an increase in the enzyme stability during storage
ABSTRACT
Objective: In this study, nano-biocomposite composed of poly [lactide-co-glycolide] [PLGA] and chitosan [CS] were electrospun through a single nozzle by dispersing the CS nano-powders in PLGA solution. The cellular behavior of human adipose derived stem cells [h-ADSCs] on random and aligned scaffolds was then evaluated
Materials and Methods: In this experimental study, the PLGA/CS scaffolds were prepared at the different ratios of 90/10, 80/20, and 70/30 [w/w]%. Morphology, cell adhesion and proliferation rate of h-ADSCs on the scaffolds were assessed using scanning electron microscope [SEM], 3-[4, 5-dimethylthiazol-2-yl]-2, 5-diphenyl tetrazolium bromide [MTT] assay and trypan blue staining respectively
Results: H-ADSCs seeded on the matrices indicated that the PLGA/CS composite matrix with aligned nanofibres and higher content of CS nano-powders gave significantly better performance than others in terms of cell adhesion and proliferation rate [P<0.05]
Conclusion: We found that CS enhanced cell adhesion and proliferation rate, and aligned nanofibers guided cell growth along the longitudinal axis of the nanofibers, which would provide a beneficial approach for tissue engineering