Premium
Inorganic–organic hybrid scaffolds for osteochondral regeneration
Author(s) -
MunozPinto Dany J.,
McMahon Rebecca E.,
Kanzelberger Melissa A.,
JimenezVergara Andrea C.,
Grunlan Melissa A.,
Hahn Mariah S.
Publication year - 2010
Publication title -
journal of biomedical materials research part a
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.849
H-Index - 150
eISSN - 1552-4965
pISSN - 1549-3296
DOI - 10.1002/jbm.a.32695
Subject(s) - materials science , chondrocyte , fibrocartilage , scaffold , matrix (chemical analysis) , biomedical engineering , bone morphogenetic protein 2 , enthesis , cartilage , biophysics , chemistry , anatomy , composite material , biochemistry , osteoarthritis , in vitro , biology , pathology , medicine , alternative medicine , tendon , articular cartilage
Ligament graft failure frequently results from poor integration of the replacement tissue with associated bone. Thus, the ability to regenerate the bone‐ligament osteochondral interface would be advantageous in ligament reconstruction. At the osteochondral interface, the tissue transitions from a bone‐like matrix to fibrocartilage. Therefore, a scaffold which promotes a spatially regulated transition in cell behavior from osteoblast‐like to chondrocyte‐like would be desirable. Previous research indicates that addition of inorganic components to organic scaffolds can enhance the deposition of bone‐like matrix by associated osteoblasts. We therefore reasoned that a gradient in the inorganic content of a hybrid inorganic–organic scaffold may induce an osteochondral‐like transition in cell phenotype and matrix production. To test this hypothesis, hydrogels were prepared from poly(ethylene glycol) (PEG) and star poly(dimethylsiloxane) (PDMS star ). As anticipated, both the matrix deposition and phenotype of encapsulated osteoblasts varied with scaffold inorganic content, although the directionality of this modulation was contrary to expectation. Specifically, osteoblasts appeared to transdifferentiate into chondrocyte‐like cells with increasing scaffold inorganic content, as indicated by increased chondroitin sulfate and collagen type II production and by upregulation of sox9, a transcription factor associated with chondrocytic differentiation. Furthermore, the deposition of bone‐like matrix (collagen type I, calcium phosphate, and osteocalcin) decreased with increasing PDMS star content. The resistance of the PDMS star ‐PEG scaffolds to protein adsorption and/or the changes in gel modulus/mesh structure accompanying PDMS star incorporation may underlie the unexpected increase in chondrocytic phenotype with increasing inorganic content. Combined, the present results indicate that PDMS star ‐PEG hybrid gels may prove promising for osteochondral regeneration. © 2010 Wiley Periodicals, Inc. J Biomed Mater Res, 2010