Bioencapsulation in Sol-Gel Glasses

Bergogne, L.; Fennouh, Souad; Livage, Jacques; Roux, Cécile

doi:10.1557/proc-519-171

Cited by 11 publications

(5 citation statements)

References 38 publications

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“…[2]- [3] may proceed in the reverse direction. Reverse processes (esterification and depolymerization) may be promoted by the addition of solvents and certain reaction conditions (6).…”

Section: Description Of the Silica Systemmentioning

confidence: 99%

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Rheological Study of the Sol–Gel Transition in Silica Alkoxides

Ponton

Warlus

Griesmar

2002

Journal of Colloid and Interface Science

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“…[2]- [3] may proceed in the reverse direction. Reverse processes (esterification and depolymerization) may be promoted by the addition of solvents and certain reaction conditions (6).…”

Section: Description Of the Silica Systemmentioning

confidence: 99%

“…• C of bio-organic molecules such as enzymes, proteins, antibodies, and even whole cells has been well-established (3)(4)(5). In fact, the trapped species maintain their bioreactivity and are protected against denaturation.…”

Section: Introductionmentioning

confidence: 99%

Rheological Study of the Sol–Gel Transition in Silica Alkoxides

Ponton

Warlus

Griesmar

2002

Journal of Colloid and Interface Science

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“…Protein tends to be denatured in the presence of alcohol, which is produced as a by‐product. Methanol, as the by‐product of TMOS‐derived gel, has a dielectric constant (30) closer to that of water (80) compared with ethanol, the by‐product of TEOS‐derived gel, and thus is less detrimental to protein function 28. On the basis of these observations, TMOS was selected for further study.…”

Section: Resultsmentioning

confidence: 99%

Matrix physicochemical properties affect activity of entrapped chlorophyllase

Kermasha

Neufeld

2005

J of Chemical Tech & Biotech

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Chlorophyllase, a membrane glycoprotein, was entrapped in various matrices, including alginate, alginate-silicate mixed gel, TMOS-based sol-gel, and their hydrophobically-modified counterparts. Chlorophyllase activity was affected by the physicochemical properties of the matrix, demonstrating lower activity in organically-modified matrices compared with the corresponding hydrophilic matrices. The advantage of adopting organically-modified matrices to facilitate the transfer of hydrophobic substrate is likely compromised by detrimental interaction between chlorophyllase and the hydrophobic components. This hypothesis is at least partly substantiated by the negligible activity demonstrated by free chlorophyllase in hydrophobic micellar media. Even though activity yields exceeded 50% in alginate beads, the release profile reveals that alginate matrix is too porous to retain chlorophyllase. Although alginate-silicate mixed gel more effectively confined chlorophyllase in the matrix, only 16% of the activity was recovered. In contrast, inorganic sol-gel yielded a chlorophyllase preparation with mass yield above 90%, and activity yield above 50%. Doping additives did not improve activity yield, which could be explained by the lower specific surface area and pore volume, and hence possible restricted accessibility of chlorophyllase by its substrate. Water/silane ratio was found to affect the sol-gel-entrapped chlorophyllase activity by influencing the gelation time and physical properties of the gel.

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“…The Si O Si network structure of is induced by the sol-gel process of silicone alkoxide precursors. It has been recognized that the sol-gel matrices are chemically and physically stable [10]. The results obtained in our previous study indicated that the Alg / AS/Alg microcapsule was more stable than the well-known Alg/ PLL /Alg microcapsule prepared under the conventional conditions [11].…”

Section: Introductionmentioning

confidence: 86%

Modification of porous aminopropyl-silicate microcapsule membrane by electrically-bonded external anionic polymers

Sakai

Ono

Ijima

et al. 2003

Journal of Biomaterials Science, Polymer Edition

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Biocompatibility and permeability of a microcapsule membrane governs the function of a microcapsule-shaped bioartificial pancreas. We have previously developed an alginate/sol-gel-synthesized aminopropyl-silicate/alginate microcapsule (Alg/AS/Alg), which had insufficient biocompatibility. The purpose of this study was to investigate whether the biocompatibility could improve by modifying the external surface with other anionic polymers and to investigate an influence of the modification on the permeability of the membrane. Four kinds of anionic polymers, poly(oxyethylene)diglycolic acid (3 kDa), heparin (15 kDa), Alg (54 kDa) and carboxymethylcellulose (CMC, 60 kDa) were used as the external anionic polymers. The heparin-bonded gel bead had the largest resistance to the diffusion of small molecules. The molecular mass cut-off point of 150 kDa required for immunoisolation was maintained for all anionic polymers. Cellular overgrowth to the implanted islet-enclosing microcapsule, a sign of insufficient biocompatibility, was suppressed by altering the external surface material from Alg to CMC. These results suggest that the biocompatibility of the Alg/AS/anionic polymer membrane can be improved by using a biocompatible anionic polymer. At the same time, it is suggested the influence on the permeability has to be investigated to develop an optimal microcapsule for bioartificial pancreas.

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Bioencapsulation in Sol-Gel Glasses

Cited by 11 publications

References 38 publications

Rheological Study of the Sol–Gel Transition in Silica Alkoxides

Rheological Study of the Sol–Gel Transition in Silica Alkoxides

Matrix physicochemical properties affect activity of entrapped chlorophyllase

Modification of porous aminopropyl-silicate microcapsule membrane by electrically-bonded external anionic polymers

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