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Updated: Aug 17, 2026
Generation of Alginate Microspheres for Biomedical Applications
Published on: August 12, 2012
Insulin-like growth factor I-releasing alginate-tricalciumphosphate composites for bone regeneration
Vera Luginbuehl1, Esther Wenk, Annette Koch
1Institute of Pharmaceutical Sciences, Drug Formulation and Delivery Group, Swiss Federal Institute of Technology Zurich (ETH Zurich), Zurich, Switzerland.
Purpose:
Development and characterization of an in situ-forming, osteoconductive, and growth factor-releasing bone implant.
Methods:
Injectable in situ-forming scaffolds were prepared from a 2% (m/v) alginate solution, tricalciumphosphate (TCP) granules, and poly(lactide-co-glycolide) microspheres (MS), loaded with the osteoinductive growth factor insulin-like growth factor I (IGF-I). Scaffolds were prepared by mixing the components followed by hydrogel formation through calcium carbonate-induced physical cross-linking of the alginate at slightly acidic pH. Physical-chemical properties and cell biocompatibility using osteoblast-like cells (MG-63 and Saos-2) of these scaffolds were investigated.
Results:
The addition of TCP to the alginate resulted in reduced swelling and gelation time and an increase in stiffness. Osteoblast-like cells (MG-63 and Saos-2) did not show toxic reactions and adhered circumferentially to the TCP granules surface. The addition of the IGF-I MS resulted in an up to sevenfold increased proliferation rate of MG-63 cells as compared to scaffold preparations without IGF-I MS. The alkaline phosphate (ALP) activity-a parameter for osteblastic activity-increased with increasing amounts of TCP in Saos-2 loaded composite scaffolds.
Conclusions:
A prototype in situ-hardening composite system for conformal filling of bone defects supporting osteoblastic activity for further clinical testing in relevant fracture models was developed and characterized.
