title: Porous silicon nanoparticle as a stabilizing support for chondroitinase.
abstract: Chondroitinase ABCI (cABCI) from Proteus vulgaris is a drug enzyme that can be used to treat spinal cord injuries. One of the main problems of chondroitinase ABC1 is its low thermal stability. The objective of the current study was to stabilize the enzyme through entrapment within porous silicon (pSi) nanoparticles. pSi was prepared by an electrochemical etch of p-type silicon using hydrofluoric acid/ethanol. The size of nanoparticles were determined 180nm by dynamic light scattering and the mean pore diameter was in the range of 40-60nm obtained by scanning electron microscopy. Enzymes were immobilized on porouse silicon nanoparticles by entrapment. The capacity of matrix was 35μg enzyme per 1mg of silicon. The immobilized enzyme displayed lower Vmaxvalues compared to the free enzyme, but Km values were the same for both enzymes. Immobilization significantly increased the enzyme stability at various temperatures (-20, 4, 25 and 37°C). For example, at 4°C, the free enzyme (in 10mM imidazole) retained 20% of its activity after 100min, while the immobilized one retained 50% of its initial activity. Nanoparticles loading capacity and the enzyme release rate showed that the selected particles could be a pharmaceutically acceptable carrier for chondroitinase.
authors: Department of Nanobiotechnology, Faculty of Biological Science, Tarbiat Modares University, Tehran, Iran.
authors: Sara
authors: S
authors: Daneshjou
authors: Department of Biochemistry, Faculty of Biological Science, Tarbiat Modares University, Tehran, Iran.
authors: Bahareh
authors: B
authors: Dabirmanesh
authors: Department of Life Science Engineering, Faculty of New Sciences and Technologies, University of Tehran, Tehran, Iran.
authors: Fereshteh
authors: F
authors: Rahimi
authors: Department of Nanobiotechnology, Faculty of Biological Science, Tarbiat Modares University, Tehran, Iran; Department of Biochemistry, Faculty of Biological Science, Tarbiat Modares University, Tehran, Iran. Electronic address: khajeh@modares.ac.ir.
authors: Khosro
authors: K
authors: Khajeh
mesh_terms: D001426:Bacterial Proteins / Q000737:chemistry*; D019765:Chondroitin ABC Lyase / Q000737:chemistry*; D002809:Chondroitin Sulfates / Q000737:chemistry; D065546:Drug Liberation; D004795:Enzyme Stability; D004800:Enzymes, Immobilized / Q000737:chemistry*; D000431:Ethanol / Q000737:chemistry; D006858:Hydrofluoric Acid / Q000737:chemistry; D007700:Kinetics; D053758:Nanoparticles / Q000737:chemistry*; D010316:Particle Size; D016062:Porosity; D011514:Proteus vulgaris / Q000737:chemistry / Q000201:enzymology; D011994:Recombinant Proteins / Q000737:chemistry; D012825:Silicon / Q000737:chemistry*; D013696:Temperature
chemical_list: D001426:Bacterial Proteins; D004800:Enzymes, Immobilized; D011994:Recombinant Proteins; D000431:Ethanol; D002809:Chondroitin Sulfates; D019765:Chondroitin ABC Lyase; D006858:Hydrofluoric Acid; D012825:Silicon
keywords: Chondroitinase ABC I; Immobilization; Porous silicon; Stability