Encapsulation of a glycosaminoglycan in hydroxyapatite/alginate capsules

Tan, Chong Shuan, Jejurikar, Aparna, Rai, Bina, Bostrom, Thor, Lawrie, Gwen and Grondahl, Lisbeth (2009) Encapsulation of a glycosaminoglycan in hydroxyapatite/alginate capsules. Journal of Biomedical Materials Research Part A, 91A 3: 866-877. doi:10.1002/jbm.a.32297


Author Tan, Chong Shuan
Jejurikar, Aparna
Rai, Bina
Bostrom, Thor
Lawrie, Gwen
Grondahl, Lisbeth
Title Encapsulation of a glycosaminoglycan in hydroxyapatite/alginate capsules
Journal name Journal of Biomedical Materials Research Part A   Check publisher's open access policy
ISSN 1549-3296
1552-4965
Publication date 2009-12-01
Year available 2008
Sub-type Article (original research)
DOI 10.1002/jbm.a.32297
Open Access Status
Volume 91A
Issue 3
Start page 866
End page 877
Total pages 12
Place of publication Hoboken, NJ, United States
Publisher John Wiley and Sons
Language eng
Subject C1
030304 Physical Chemistry of Materials
920116 Skeletal System and Disorders (incl. Arthritis)
Abstract The development of suitable vehicles for the delivery of growth-inducing factors to fracture sites is a challenging area of bone repair. Bone-specific glycosaminoglycan molecules are of particular interest because of their high stability and proven effect on bone growth. Calcium alginate capsules are popular as delivery vehicles because of their low immunogenic response; they offer a versatile route that enables the controlled release of heparin (a member of the glycosaminoglycan family). In this study, hydroxyapatite (HA)/alginate composite capsules are explored as novel drug delivery vehicles for heparin, using both medium- and low-viscosity alginates. The composition, structure, and stability of the capsules are fully characterized and correlated to the release of heparin in vitro. Heparin is found to associate both with the alginate matrix through polymeric flocculation and also with the HA crystals in the composite beads. The mechanism by which heparin is released is dictated by the stability of the capsule in a particular release media and by the composition of the capsule. The use of medium-viscosity alginate is advantageous with respect to both drug loading and prolonging the release. The inclusion of HA increases the encapsulation efficiency, but because of its destabilizing effect to the alginate hydrogel matrix, it also increases the rate of heparin release. The bioactivity of heparin is fully retained throughout the assembly and release processes. (C) 2008 Wiley Periodicals, Inc. J Biomed Mater Res 91A: 866-877, 2009
Formatted abstract
The development of suitable vehicles for the delivery of growth-inducing factors to fracture sites is a challenging area of bone repair. Bone-specific glycosaminoglycan molecules are of particular interest because of their high stability and proven effect on bone growth. Calcium alginate capsules are popular as delivery vehicles because of their low immunogenic response; they offer a versatile route that enables the controlled release of heparin (a member of the glycosaminoglycan family). In this study, hydroxyapatite (HA)/alginate composite capsules are explored as novel drug delivery vehicles for heparin, using both medium- and low-viscosity alginates. The composition, structure, and stability of the capsules are fully characterized and correlated to the release of heparin in vitro. Heparin is found to associate both with the alginate matrix through polymeric flocculation and also with the HA crystals in the composite beads. The mechanism by which heparin is released is dictated by the stability of the capsule in a particular release media and by the composition of the capsule. The use of medium-viscosity alginate is advantageous with respect to both drug loading and prolonging the release. The inclusion of HA increases the encapsulation efficiency, but because of its destabilizing effect to the alginate hydrogel matrix, it also increases the rate of heparin release. The bioactivity of heparin is fully retained throughout the assembly and release processes.
Keyword Hydrogel
Hydroxyapatite
Alginate
Controlled release
Release mechanism
Heparin
Q-Index Code C1
Q-Index Status Confirmed Code
Institutional Status UQ

 
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Created: Fri, 17 Apr 2009, 19:13:17 EST by Jennifer Falknau on behalf of School of Chemistry & Molecular Biosciences