Enzyme encapsulation in layer-by-layer engineered polymer multilayer capsules

Langmuir

Volumn 16, Issue 4, 2000, Pages 1485-1488

  Caruso, Frank ^a   Trau, Dieter ^b   Möhwald, Helmuth ^a   Renneberg, Reinhard ^b  

^a MAX PLANCK INSTITUTE OF COLLOIDS AND INTERFACES   (Germany)

^b HONG KONG UNIVERSITY OF SCIENCE AND TECHNOLOGY   (Hong Kong)

Author keywords

[No Author keywords available]

Indexed keywords

ADSORPTION; CATALYSIS; CONTROLLED DRUG DELIVERY; CRYSTALS; DEGRADATION; ENCAPSULATION; POLYELECTROLYTES;

INCUBATION; POLYMER ENCAPSULATED ENZYME; POLYMER MULTILAYER COATING;

ENZYMES;

EID: 0033894827     PISSN: 07437463     EISSN: None     Source Type: Journal    
DOI: 10.1021/la991161n     Document Type: Article

References (20)

1. Langer, R. Nature 1998, 392, 5-10.
2. Park, K. Controlled Drug Delivery: Challenges and Strategies; American Chemical Society: Washington, DC, 1997.
3. Kreuter, J. Colloidal Drug Delivery Systems; Marcel Dekker: New York, 1994.
4. Yokoyama, M.; Okano, T. Adv. Drug Delivery Rev. 1996, 21, 77-80.
5. Biochemica Information; Boehringer: Mannheim Germany, 1987; pp 15-16.
6. Caruso, F.; Donath, E.; Möhwald, H. J. Phys. Chem. B 1998, 102, 2011-2016.
7. Sukhorukov, G. B.; Donath, E.; Davis, S. A.; Lichtenfeld, H.; Caruso, F.; Popov, V. I.; Möhwald, H. Polym. Adv. Technol. 1998, 9, 759-767.
8. Donath, E.; Sukhorukov, G.B.; Caruso, F.; Davis, S. A.; Möhwald, H. Angew. Chem. 1998, 110, 2324-2327; Angew. Chem., Int. Ed. 1998, 37, 2201-2205.
9. Donath, E.; Sukhorukov, G.B.; Caruso, F.; Davis, S. A.; Möhwald, H. Angew. Chem. 1998, 110, 2324-2327; Angew. Chem., Int. Ed. 1998, 37, 2201-2205.
10. Caruso, F.; Lichtenfeld, H.; Donath, E.; Möhwald, H. Macromolecules 1999, 32, 2317-2328.
11. Caruso, F.; Caruso, R. A.; Möhwald, H. Science 1998, 282, 1111-1114.
12. -1 solution containing 1 M potassium acetate (pH 5 at 4°C) using the same procedure and conditions. Subsequent alternating PSS and PAH layers were deposited in identical fashion until the desired number of polymer multilayers was achieved.
13. AFM images were obtained with a Digital Instruments Nanoscope IIIa AFM in tapping mode (TM) on samples deposited onto cleaned glass slides and air-dried.
14. 6-9 The mobility u was converted into a ζ-potential using the Smoluchowski relation ζ=uη/∈, where η and ∈ are the viscosity and permittivity of the solution, respectively.
15. Several drops of the polymer multilayer-coated crystal solution were placed on a cleaned glass slide and most of the water was allowed to evaporate. An alkaline solution of pH > 11 was then pipetted onto an area on the slide near that which contained the encapsulated enzyme crystals. The alkaline solution was then allowed to make contact with the coated enzymes, and the polymer capsule rupture and enzyme release were monitored using optical and video microscopy. Rupture occurred immediately upon contact with the alkaline solution front. It should be noted that this release process may not be suitable for certain applications. To this end, we are currently employing a range of other polymers in order to effect enzyme release.
16. Samples for transmission electron microscopy (TEM, Philips CM 12 microscope operating at 120 kV) were prepared by deposition of aqueous solutions of the hollow polymer capsules upon a carbon-coated copper grid, allowing them to air-dry for 1 min, and then blotting off the extra solution.
17. Hollow polymer capsules were obtained by exposing the polymer multilayer-coated capsules to a deproteinizer solution (Medical instruments; active constituent is sodium hypochlorite) for 15 min and washing three times with 100 mM sodium chloride solution. Although the pH of the deproteinizer solution is approximately 12, no capsule rupture was observed. This is most likely due to the rapid decomposition of the enzyme, hence avoiding any significant increase in osmotic pressure buildup in the capsules.
18. 2) at 240 nm. The concentration of the catalase was determined spectrophotometrically at 280 and 405 nm (soret band). The specific activity was obtained by dividing the measured activity by the enzyme concentration. The specific activity of the uncoated catalase was measured in the same way and used for comparison. See also, for example: Tijsen, P. Practice and Theory of Enzyme Immunoassays, 8th Impression, Elsevier: Amsterdam, 1993; pp 202-203.15.
19. 10 mg of protease (Streptomyces griseus; Sigma P6911; activity = 5.2 U/mg solid) was dissolved in 500 μL of phosphate buffered saline (PBS, pH 7.0) (100 U/ml) and used as the stock solution. Samples (200 μL) of the polyelectrolyte-coated catalase and solublilized catalase were separately incubated in a water bath at 37°C with either 30 μL of the stock protease solution or 30 μL of PBS (control experiment). The starting activity of the catalase for all samples was approximately 12 000 U/mL catalase. The starting activities were normalized to 100%. The final protease activity in the sample was 13 U/mL. Proteolysis of the catalase was determined by measuring the decrease in the catalase enzyme activity. The catalase activity measurements where carried out according to the previously described method (i.e., by spectrophotometric detection (240 nm) of the decomposition of hydrogen peroxide, see ref 17). Samples (5 μL) were diluted and used for the activity measurements.
20. Caruso, F.; Niikura, K.; Furlong, D. N.; Okahata, Y. Langmuir 1997, 13, 3427-3433.