Fumarate Copolymer–Chitosan Cross‐Linked Scaffold Directed to Osteochondrogenic Tissue Engineering

Abstract

Natural and synthetic cross-linked polymers allow the improvement of cytocompatibility and mechanical properties of the individual polymers. In osteochondral lesions of big size it will be required the use of scaffolds to repair the lesion. In this work a borax cross-linked scaffold based on fumarate-vinyl acetate copolymer and chitosan directed to osteochondrondral tissue engineering is developed. The cross-linked scaffolds and physical blends of the polymers are analyzed in based on their morphology, glass transition temperature, and mechanical properties. In addition, the stability, degradation behavior, and the swelling kinetics are studied. The results demonstrate that the borax cross-linked scaffold exhibits hydrogel behavior with appropriated mechanical properties for bone and cartilage tissue regeneration. Bone marrow progenitor cells and primary chondrocytes are used to demonstrate its osteo- and chondrogenic properties, respectively, assessing the osteo- and chondroblastic growth and maturation, without evident signs of cytotoxicity as it is evaluated in an in vitro system.

Nanostructured fumarate copolymer‐chitosan crosslinked scaffold: Anin vitroosteochondrogenesis regeneration study

“…DSC measurements for PFVH‐CH with and without borax showed a glass transition temperature ( T g ) of 64.8 and 62.15°C, respectively. Moreover, these values are higher than those previously found for PFVH ( T g = 60.5°C) . The increase on T g of PFVH‐CH‐cross linked by borax could be attributed to the restriction on the catenary movements caused by the crosslinking between both polymers with borax.…”

“…First, diisopropylfumarate (DIPF)‐vinyl acetate (VA) copolymer was synthesized by mass radical polymerization, hydrolyzed and characterized following a procedure previously described . Briefly, both monomers (DIPF:VA, 75:25) together with the previously weighed mass of the initiator (40 m M ) were charged into a reaction vessel and then purged with N 2 during 30 min.…”

“…This mixture was designated as PFVH‐CH‐B. The maximum swelling and water absorption capacity of the scaffolds were determined as it was previously reported …”

“…Additionally, osteogenic induction of BMPC was performed by incubating the cells in basal media plus β‐glycerol‐phosphate and ascorbic acid during different periods of time: 15 and 21 days. After that time points type I collagen was evaluated through the colorimetric assay with Sirius red and ALP activity by the conversion of p ‐nitrophenyl phosphate to p ‐nitrophenol in a glycine buffer pH 10, and mineral deposits were analyzed with the colorimetric assays of Alizarin S red …”

“…Concerning materials of which scaffolds are made of, polymer blending and crosslinking are one of the most effective approaches for providing new, desirable polymeric materials for particular applications. In this sense, we have previously designed and characterized a fumaric copolymer crosslinked with chitosan . In that work, we demonstrated that the scaffold obtained promote osteo‐ and chondrogenic development, with very low inflammatory response and an adequate degradation rate to promote osteochondral tissue reparation.…”