Abstract
Cellular encapsulation within alginate hydrogel capsules has broad applications in tissue engineering. In seeking to improve the inherent instability of ionically cross-linked alginate hydrogels, we previously demonstrated the covalent stabilization of Ba 2+ cross-linked alginate-azide beads via chemoselective Staudinger ligation using a 1-methyl-2-diphenylphosphino-terephthalate (MDT) terminated poly(ethylene glycol) (PEG) linker. In this study, we functionalized variant PEG, linear and branched, and alginate polymers with MDT groups to evaluate the effect of size, structural design, number of functional groups, and charge on the resulting hydrogel bead. All cross-linkers resulted in enhanced covalent stabilization of alginate beads, with significant decreases in swelling and resistance to dissolution via Ba 2+ chelation. The MDT-functionalized alginate resulted in the most stable and homogeneous bead, with the most restrictive permeability even after EDTA exposure. Co-encapsulation of MIN6 cells within the cross-linked alginate hydrogel beads resulted in minimal effects on viability, whereas the degree of proliferation following culture varied with cross-linker type. Altogether, the results illustrate that manipulating the cross-linker structural design permits flexibility in resulting alginate beads characteristics. Covalent stabilization of alginate hydrogel beads with these chemoselective alginate and PEG-based cross-linkers provides a unique platform for cellular encapsulation.
| Original language | English |
|---|---|
| Pages (from-to) | 47-57 |
| Number of pages | 11 |
| Journal | Journal of Biomedical Materials Research - Part A |
| Volume | 99 A |
| Issue number | 1 |
| DOIs | |
| State | Published - Oct 1 2011 |
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Keywords
- alginate
- cross-linker design
- encapsulation
- PEG
- Staudinger ligation
ASJC Scopus subject areas
- Biomedical Engineering
- Biomaterials
- Ceramics and Composites
- Metals and Alloys
Cite this
Covalent stabilization of alginate hydrogel beads via Staudinger ligation : Assessment of poly(ethylene glycol) and alginate cross-linkers. / Gattás-Asfura, Kerim M.; Fraker, Christopher; Stabler, Cherie L.
In: Journal of Biomedical Materials Research - Part A, Vol. 99 A, No. 1, 01.10.2011, p. 47-57.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Covalent stabilization of alginate hydrogel beads via Staudinger ligation
T2 - Assessment of poly(ethylene glycol) and alginate cross-linkers
AU - Gattás-Asfura, Kerim M.
AU - Fraker, Christopher
AU - Stabler, Cherie L.
PY - 2011/10/1
Y1 - 2011/10/1
N2 - Cellular encapsulation within alginate hydrogel capsules has broad applications in tissue engineering. In seeking to improve the inherent instability of ionically cross-linked alginate hydrogels, we previously demonstrated the covalent stabilization of Ba 2+ cross-linked alginate-azide beads via chemoselective Staudinger ligation using a 1-methyl-2-diphenylphosphino-terephthalate (MDT) terminated poly(ethylene glycol) (PEG) linker. In this study, we functionalized variant PEG, linear and branched, and alginate polymers with MDT groups to evaluate the effect of size, structural design, number of functional groups, and charge on the resulting hydrogel bead. All cross-linkers resulted in enhanced covalent stabilization of alginate beads, with significant decreases in swelling and resistance to dissolution via Ba 2+ chelation. The MDT-functionalized alginate resulted in the most stable and homogeneous bead, with the most restrictive permeability even after EDTA exposure. Co-encapsulation of MIN6 cells within the cross-linked alginate hydrogel beads resulted in minimal effects on viability, whereas the degree of proliferation following culture varied with cross-linker type. Altogether, the results illustrate that manipulating the cross-linker structural design permits flexibility in resulting alginate beads characteristics. Covalent stabilization of alginate hydrogel beads with these chemoselective alginate and PEG-based cross-linkers provides a unique platform for cellular encapsulation.
AB - Cellular encapsulation within alginate hydrogel capsules has broad applications in tissue engineering. In seeking to improve the inherent instability of ionically cross-linked alginate hydrogels, we previously demonstrated the covalent stabilization of Ba 2+ cross-linked alginate-azide beads via chemoselective Staudinger ligation using a 1-methyl-2-diphenylphosphino-terephthalate (MDT) terminated poly(ethylene glycol) (PEG) linker. In this study, we functionalized variant PEG, linear and branched, and alginate polymers with MDT groups to evaluate the effect of size, structural design, number of functional groups, and charge on the resulting hydrogel bead. All cross-linkers resulted in enhanced covalent stabilization of alginate beads, with significant decreases in swelling and resistance to dissolution via Ba 2+ chelation. The MDT-functionalized alginate resulted in the most stable and homogeneous bead, with the most restrictive permeability even after EDTA exposure. Co-encapsulation of MIN6 cells within the cross-linked alginate hydrogel beads resulted in minimal effects on viability, whereas the degree of proliferation following culture varied with cross-linker type. Altogether, the results illustrate that manipulating the cross-linker structural design permits flexibility in resulting alginate beads characteristics. Covalent stabilization of alginate hydrogel beads with these chemoselective alginate and PEG-based cross-linkers provides a unique platform for cellular encapsulation.
KW - alginate
KW - cross-linker design
KW - encapsulation
KW - PEG
KW - Staudinger ligation
UR - http://www.scopus.com/inward/record.url?scp=80051878649&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=80051878649&partnerID=8YFLogxK
U2 - 10.1002/jbm.a.33162
DO - 10.1002/jbm.a.33162
M3 - Article
C2 - 21793196
AN - SCOPUS:80051878649
VL - 99 A
SP - 47
EP - 57
JO - Journal of Biomedical Materials Research - Part A
JF - Journal of Biomedical Materials Research - Part A
SN - 1549-3296
IS - 1
ER -