In vivo evaluation of a bioactive scaffold for bone tissue engineering

Abstract

Revision cases of total hip implants are complicated by the significant amount of bone loss. New materials and/or approaches are needed to provide stability to the site, stimulate bone formation, and ultimately lead to fully functional bone tissue. Porous bioactive glasses (prepared from 45S5 granules, 45% SiO2, 24.5% Na2O, 24.5% CaO, and 6% P2O5) have been developed as scaffolds for bone tissue engineering and have been studied in vitro. In this study, we investigated the incorporation of tissue-engineered constructs utilizing these scaffolds in large, cortical bone defects in the rat simulating revision conditions. With implantation times of 2, 4, and 12 weeks the results were compared to those using the bioactive ceramic scaffold alone. Two tissue-engineered constructs were studied: osteoprogenitor cells that were either seeded onto the scaffold prior to implantation ("primary") or those that were culture expanded to form bonelike tissue on the scaffold prior to implantation ("hybrid"). Defects treated with the hybrid had the greatest amount of bone in the available pore space of the defect over all other groups at 2 weeks (p < 0.05). For both the primary and hybrid groups, woven and lamellar bone was present along the interface of the scaffold and the host cortex and within the porous space of the scaffold at 2 weeks. By 4 weeks, very uniform, lamellar bone was present throughout the scaffold for both tissue-engineered groups. The amount of bone significantly increased over time for all groups while the bioactive ceramic gradually resorbed by 40% at 12 weeks (p < 0.05). Structural properties of the treated long bones improved over time. Long bones treated with the hybrid had an early return in torsional stiffness by 2 weeks. Both tissue-engineered constructs achieved normal torsional strength and stiffness by 4 weeks as compared to the scaffold alone, which achieved this by 12 weeks. Porous, surface modified bioactive ceramic is a promising scaffold material for tissue-engineered bone repair.

Bone tissue engineering therapeutics: controlled drug delivery in three-dimensional scaffolds

“…However, some of these ceramics degrade very slowly, with crystalline HA being a very stable CaP in the biological environment (table 1) (Marcacci et al 2007;Chen et al 2008). More recently, bioactive silicate glasses and glass -ceramics have been investigated in their application as scaffolds (Livingston et al 2002;Di Nunzio et al 2004;Vitale-Brovarone et al 2004;Chen, Q. Z. et al 2006;Fu et al 2007;Vitale-Brovarone et al 2008).…”

Self‐hardening calcium phosphate composite scaffold for bone tissue engineering

“…Another study used a mesh on the tensile side of CPC to increase the work-to-fracture [45]. Macropores were built into implants to facilitate cell infiltration, tissue ingrowth, and implant fixation [3,6,17,18,20,24,[26][27][28]301. Our recent studies incorporated a variety of fibers, as well as water-soluble porogens, into CPC to obtain strength as well as macropores for bone ingrowth [46,49].…”

Bone tissue engineering by using a combination of polymer/Bioglass composites with human adipose-derived stem cells

“…Indeed, numerous in vivo and in vitro studies have shown that 45S5 Bioglass ® can stimulate bone regeneration (Bosetti et al 2003;Gough et al 2004;Livingston et al 2002;Loty et al 2001;Tsigkou et al 2007;Xynos et al 2000). As a result, Bioglass ® is said to be both osteoproductive and osteoconductive.…”