Poly(hydroxybutyrate-co-hydroxyvalerate) nanocapsules as enzyme carriers for cancer therapy: an in vitro study

Date

2002-05-01

Author

Baran, ET
Ozer, N
Hasırcı, Vasıf Nejat

Metadata

Show full item record

This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Item Usage Stats

195
views

0
downloads

In the present paper, poly(3-hydroxybutyrate-co-3-hydroxyvalerate) nanocapsules were prepared by a double emulsion-solvent evaporation procedure (w/o/w) for the encapsulation of model enzymes (L-asparaginase, catalase, glucose oxidase) and bovine serum albumin. To increase the encapsulation efficiency and activity of the encapsulated enzyme, numerous modifications were made in the compositions of the phases of double emulsion. For the preparation of low molecular weight PHBV, the polymer was treated with sodium borohydride. A 14-fold decrease in molecular weight (from 297 000 to 21 000) was observed upon 4 h of incubation. Although the amount of encapsulated protein was not increased, the enzyme activity increased upon use of low molecular weight PHBV, indicating that these nanocapsules have a higher permeability to solutes (reactants and products). The adjustment of the second water phase to the isoelectric point of the proteins significantly increased the encapsulation yields of catalase, L-asparaginase and BSA. Likewise, polyethylene glycol coupling significantly increased the entrapment efficiency as well as the activity of catalase and L-asparaginase. A combination of the various optimum preparation conditions further increased the encapsulated catalase activity (about sixfold) in comparison to the initial basic conditions (with no modification and no isoelectric point adjustment).

Subject Keywords

poly(3-hydroxybutyrate-co-3-hydroxyvalerate), Water-in-oil-in-water, Solvent evaporation, Nanocapsule, Enzyme encapsulation

URI

https://hdl.handle.net/11511/31331

Journal

JOURNAL OF MICROENCAPSULATION

DOI

https://doi.org/10.1080/02652040110105355

Collections

Graduate School of Natural and Applied Sciences, Article

Suggestions

OpenMETU
Core

Immobilization of glucose isomerase in surface-modified alginate gel beads TÜMTÜRK, HAYRETTİN; DEMİREL, Gökhan; ALTINOK, HAYDAR; AKSOY, SERPİL; Hasırcı, Nesrin (2008-04-01) In this study, glucose isomerase enzyme was entrapped into modified and nonmodified calcium alginate gel beads. Various characteristics of free and immobilized enzymes such as the optimum pH, temperature and dependence of activity on storage and operational stability were evaluated. The optimum pH and temperature of free and immobilized glucose isomerase were found to be the same values as 7.5 and 60C, respectively. For free and immobilized enzymes, kinetic parameters were calculated as 1.79 x 10(-2) and 8....
Impact modified poly(ethylene terephthalate)-organoclay nanocomposites Alyamaç, Elif; Yılmazer, Ülkü; Department of Chemistry (2004) This study was conducted to investigate the effects of component concentrations and addition order of the components, on the final properties of ternary nanocomposites composed of poly(ethylene terephthalate), organoclay, and an ethylene/methyl acrylate/glycidyl methacrylate (E-MA-GMA) terpolymer acting as an impact modifier for PET. In this context, first, the optimum amount of the impact modifier was determined by melt compounding binary PET-terpolymer blends in a corotating twin-screw extruder. The amoun...
Immobilization of invertase and glucose oxidase in conducting H-type polysiloxane/polypyrrole block copolymers Gursel, A; Alkan, S; Toppare, Levent Kamil; Yagci, Y (Elsevier BV, 2003-01-01) In this study, immobilizations of enzymes, invertase and glucose oxidase, were achieved in conducting copolymers of N-pyrrolyl terminated polydimethylsiloxane/polypyrrole (PDMS/PPy) matrices via electrochemical polymerization. The kinetic parameters, v(max) (maximum reaction rate) and K-m (substrate affinity), of both free and immobilized enzymes were determined. The effect of supporting electrolytes, p-toluene sulfonic acid and sodium dodecyl sulfate, on enzyme activity and film morphologies was examined. ...
Ni-MCM-41 type mesoporous catalysts synthesized by one-pot hydrothermal procedure for steam reforming of ethanol Ozdogan, Ekin; Doğu, Timur; DOĞU, GÜLŞEN (2007-01-02) In the present study, Ni incorporated MCM-41 structured mesoporous catalysts with a Ni/Si atomic ratio of 0.036 and 0.15 were prepared by a direct hydrothermal synthesis procedure. These catalysts had surface area values of 860.5 m(2)/g (Ni-MCM-41 having a Ni/Si ratio of 0.036) and 944.9 m(2)/g (Ni-MCM-41 having a Ni/Si ratio of 0.15). They also had narrow pore size distributions with average pore diameters of 2.7-2.6 nm respectively. Ni MCM-41 synthesized by the one-pot hydrothermal synthesis procedure sho...
Poly-beta-hydroxybutyrate production by lactic acid bacteria Aslim, B; Caliskan, F; Beyatli, Y; Gündüz, Ufuk (1998-02-15) Poly-beta-hydroxybutyrate was determined in lactic acid bacteria belonging to the genera Lactobacillus, Lactococcus, Pediococcus and Streptococcus. Lactobacilli were grown in MRS broth, the others were grown in Elliker broth medium. Cell biomass was obtained by centrifugation. The cell walls were lysed with sodium hypochlorite. Poly-beta-hydroxybutyrate was extracted using chloroform in a Soxhlet system. Then it was converted to crotonic acid using sulfuric acid and the amount of crotonic acid was measured ...

Citation Formats

E. Baran, N. Ozer, and V. N. Hasırcı, “Poly(hydroxybutyrate-co-hydroxyvalerate) nanocapsules as enzyme carriers for cancer therapy: an in vitro study,” JOURNAL OF MICROENCAPSULATION, pp. 363–376, 2002, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/31331.