Biomineralized Polysaccharide Capsules for Encapsulation, Organization, and Delivery of Human Cell Types and Growth Factors

• Published in: Advanced functional materials Vol. 15; no. 6; pp. 917 - 923
• Main Authors: Green, D. W., Leveque, I., Walsh, D., Howard, D., Yang, X., Partridge, K., Mann, S., Oreffo, R. O. C.
• Format: Journal Article
• Language: English
• Published: Weinheim WILEY-VCH Verlag 01-06-2005; WILEY‐VCH Verlag
• Subjects: Alginate; Biomineralization; Chitosan; Controlled release; Drug delivery; Encapsulation; Tissue engineering
• ISSN: 1616-301X; 1616-3028
• DOI: 10.1002/adfm.200400322

The construction of biomimetic microenvironments with specific chemical and physical cues for the organization and modulation of a variety of cell populations is of key importance in tissue engineering. We show that a range of human cell types, including promyoblasts, chondrocytes, adipocytes, adenovirally transduced osteoprogenitors, immunoselected mesenchymal stem cells, and the osteogenic factor, rhBMP‐2 (BMP: bone morphogenic protein), can be successfully encapsulated within mineralized polysaccharide capsules without loss of function in vivo. By controlling the extent of mineralization within the alginate/chitosan shell membrane, degradation of the shell wall and release of cells or rhBMP‐2 into the surrounding medium can be regulated. In addition, we describe for the first time the ability to generate bead‐in‐bead capsules consisting of spatially separated cell populations and temporally separated biomolecule release, entrapped within alginate/chitosan shells of variable thickness, mineralization, and stability. Such materials offer significant potential as multifunctional scaffolds and delivery vehicles in tissue regeneration of hard and soft tissues.
Biomineralized polysaccharide capsules (see Figure, center, and cover) provide microenvironments for encapsulation of human cells (top left) and biomolecules that lead to tissue formation. Embedded “host” capsules (bottom left) enable spatial separation of cell populations and temporal release of biological factors. Bone matrix formation is demonstrated (bottom right).