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Diffusion of glucose and insulin in a swelling N-isopropylacrylamide gel

Andersson, M; Axelsson, Anders LU and Zacchi, Guido LU (1997) In International Journal of Pharmaceutics 157(2). p.199-208
Abstract
The diffusional characteristics for poly(N-isopropylacrylamide) (NiPAAm) gel have been investigated. This gel is a critical gel which means that small changes in the environment influence the gel volume considerably. The effective diffusion coefficients for the solutes glucose and insulin were determined in batch experiments with the solutes diffusing out from small cylindrical gel bodies with diameters of 2.4-2.9 mm and at temperatures below the critical temperature: 10, 20 and 30 degrees C. The effective diffusion coefficients were obtained by fitting the experimental data to a mathematical model considering back-mixing and time delay in the experimental set-up, dilution due to the adsorbed liquid on the gel bodies and partition due to... (More)
The diffusional characteristics for poly(N-isopropylacrylamide) (NiPAAm) gel have been investigated. This gel is a critical gel which means that small changes in the environment influence the gel volume considerably. The effective diffusion coefficients for the solutes glucose and insulin were determined in batch experiments with the solutes diffusing out from small cylindrical gel bodies with diameters of 2.4-2.9 mm and at temperatures below the critical temperature: 10, 20 and 30 degrees C. The effective diffusion coefficients were obtained by fitting the experimental data to a mathematical model considering back-mixing and time delay in the experimental set-up, dilution due to the adsorbed liquid on the gel bodies and partition due to the exclusion effect. The effective diffusion coefficient for glucose increases from 2.7.10(-10) to 4.7.10(-10) m(2)/s when the temperature increases from 10 to 30 degrees C, following the Wilke-Chang relationship. This implies that the effect of the network is negligible compared with the effect of the temperature. However, for a solute with a molecular weight of about 6000 the network has a considerable effect. The effective diffusion coefficient for insulin increases from 4.4.10(-10) to 5.9.10(-10) m(2)/s when the temperature increases from 10 to 30 degrees C, which is less than expected from the Wilke-Chang relationship. This indicates an increased resistance for diffusion inside the gel due to shrinking. (C) 1997 Elsevier Science B.V. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
diffusion, gel, glucose, insulin, N-isopropylacrylamide
in
International Journal of Pharmaceutics
volume
157
issue
2
pages
199 - 208
publisher
Elsevier
external identifiers
  • wos:A1997YF81300009
  • scopus:0030784650
ISSN
1873-3476
DOI
10.1016/S0378-5173(97)00243-3
language
English
LU publication?
yes
id
40c7d66e-8821-4870-8a19-c1a1ade1a5a4 (old id 3911473)
date added to LUP
2013-06-28 13:47:11
date last changed
2017-01-01 04:46:43
@article{40c7d66e-8821-4870-8a19-c1a1ade1a5a4,
  abstract     = {The diffusional characteristics for poly(N-isopropylacrylamide) (NiPAAm) gel have been investigated. This gel is a critical gel which means that small changes in the environment influence the gel volume considerably. The effective diffusion coefficients for the solutes glucose and insulin were determined in batch experiments with the solutes diffusing out from small cylindrical gel bodies with diameters of 2.4-2.9 mm and at temperatures below the critical temperature: 10, 20 and 30 degrees C. The effective diffusion coefficients were obtained by fitting the experimental data to a mathematical model considering back-mixing and time delay in the experimental set-up, dilution due to the adsorbed liquid on the gel bodies and partition due to the exclusion effect. The effective diffusion coefficient for glucose increases from 2.7.10(-10) to 4.7.10(-10) m(2)/s when the temperature increases from 10 to 30 degrees C, following the Wilke-Chang relationship. This implies that the effect of the network is negligible compared with the effect of the temperature. However, for a solute with a molecular weight of about 6000 the network has a considerable effect. The effective diffusion coefficient for insulin increases from 4.4.10(-10) to 5.9.10(-10) m(2)/s when the temperature increases from 10 to 30 degrees C, which is less than expected from the Wilke-Chang relationship. This indicates an increased resistance for diffusion inside the gel due to shrinking. (C) 1997 Elsevier Science B.V.},
  author       = {Andersson, M and Axelsson, Anders and Zacchi, Guido},
  issn         = {1873-3476},
  keyword      = {diffusion,gel,glucose,insulin,N-isopropylacrylamide},
  language     = {eng},
  number       = {2},
  pages        = {199--208},
  publisher    = {Elsevier},
  series       = {International Journal of Pharmaceutics},
  title        = {Diffusion of glucose and insulin in a swelling N-isopropylacrylamide gel},
  url          = {http://dx.doi.org/10.1016/S0378-5173(97)00243-3},
  volume       = {157},
  year         = {1997},
}