Bone formation in transforming growth factor β‐1‐coated porous poly(propylene fumarate) scaffolds

Abstract

This study determined the bone growth into pretreated poly(propylene fumarate) (PPF) scaffolds implanted into a subcritical size, rabbit cranial defect. PPF scaffolds were constructed by using a photocrosslinking-porogen leaching technique. These scaffolds were then either prewetted (PPF-Pw), treated with RF glow-discharge (PPF-Gd), coated with fibronectin (PPF-Fn), or coated with rhTGF-beta1 (PPF-TGF-beta1). One of each scaffold type was then placed into the cranium of nine rabbits. The rabbits were sacrificed after 8 weeks, and the scaffolds were retrieved for histological analysis. The most bone formation was present in the PPF-TGF-beta1 implants; the newly formed bone had a trabecular appearance together with bone marrow-like tissue. Little or no bone formation was observed in implants without rhTGF-beta1. These histological findings were confirmed by image analysis. Bone surface area, bone area percentage, pore fill percentage, and pore area percentage were significantly higher in the rhTGF-beta1-coated implants than in the noncoated implants. No statistical difference was seen between the PPF-Fn, PPF-Pw, or PPF-Gd scaffolds for these parameters. Quadruple fluorochrome labeling showed that in PPF-TGF-beta1 implants bone formation mainly started in the interior of a pore and proceeded toward the scaffold. We conclude that (a) PPF-TGF-beta1 scaffolds can indeed adequately induce bone formation in porous PPF, and (b) PPF scaffolds prepared by the photocrosslinking-porogen leaching technique are good candidates for the creation of bone graft substitutes.

Simulation of bone tissue formation within a porous scaffold under dynamic compression

“…This interpretation is consistent with biological observation of tissue deposition within scaffold (Bölgen et al 2008). Nonetheless, other authors show that bone formation mainly started in the interior of a pore and proceeded toward the scaffold (Vehof et al 2002). In fact, in the model results, we can see that mechanical stimulus S is highly close to pore walls than that in the middle of the pore.…”

Bioactive and bioresorbable cellular cubic-composite scaffolds for use in bone reconstruction

“…Although various types of polymer-only porous scaffold have been proposed previously, none have shown sufficient hard-tissue affinity (Burdick et al 2003), and suitable chemical surface-modifications have not yet been realized (Vehof et al 2002).…”

Vascularized Bone Tissue Engineering: Approaches for Potential Improvement

“…Among synthetic polymers, poly (a-hydroxy) esters, such as poly (lactic acid), 74 poly (glycolic acid), 75 PLGA, 76 and polyurethanes, 77,78 have been widely utilized for bone regeneration. Other synthetic polymers that are of interest for bone repair are poly (propylene fumarate) (PPF), [79][80][81][82] polyanhydride, 83,84 and poly (ethylene oxide)/poly (butylene terephthalate) copolymers. 85,86 Synthetic biodegradable polymers have higher mechanical properties than natural polymers and can be easily processed.…”