Crosslinked poly(ϵ‐caprolactone/D,L‐lactide)/bioactive glass composite scaffolds for bone tissue engineering

Abstract

A series of elastic polymer and composite scaffolds for bone tissue engineering applications were designed. Two crosslinked copolymer matrices with 90/10 and 30/70 mol % of epsilon-caprolactone (CL) and D,L-lactide (DLLA) were prepared with porosities from 45 to 85 vol % and their mechanical and degradation properties were tested. Corresponding composite scaffolds with 20-50 wt % of particulate bioactive glass (BAG) were also characterized. Compressive modulus of polymer scaffolds ranged from 190+/-10 to 900+/-90 kPa. Lactide rich scaffolds absorbed up to 290 wt % of water in 4 weeks and mainly lost their mechanical properties. Caprolactone rich scaffolds absorbed no more than 110 wt % of water in 12 weeks and kept their mechanical integrity. Polymer and composite scaffolds prepared with P(CL/DLLA 90/10) matrix and 60 vol % porosity were further analyzed in simulated body fluid and in osteoblast culture. Cell growth was compromised inside the 2 mm thick three-dimensional scaffold specimens as a static culture model was used. However, composite scaffolds with BAG showed increased osteoblast adhesion and mineralization when compared to neat polymer scaffolds.

Bioactive glass and glass-ceramic scaffolds for bone tissue engineering

“…In 2003, Boccaccini and Maquet [42] reported for the first time on the successful fabrication of porous foam-like bioactive glass containing poly(lactide-co-glycolide) (PLGA) composites, which exhibited well-defined, oriented and interconnected porosity. Since then, many studies have been carried out to optimize and investigate bone TE composite scaffolds concerning material combinations, bioactive properties, degradation characteristics [161,164,165,168], in vitro [47,[161][162][163]169] and in vivo behavior [47,164], as well as mechanical properties [50,81,160].…”

“…Extensive work has been also carried out to investigate the cellular response to bioactive glass containing composites concerning composition, particle concentration and particle size effect in vitro and in vivo [46][47][48][161][162][163][164]166,[169][170][171]174]. For example, Lu et al [179] showed that for PLGA/bioactive glass films (0, 10, 25, 50 wt %), the growth, mineralization and differentiation of human osteoblast-like SaOS-2 cells (Figure 15), as well as the kinetics of Ca-P layer formation and the resulting Ca-P chemistry were dependent on BG content.…”

Polymer Composites for Bone Reconstruction

“…To carry out biological testing, the cell culture and histological laboratory, standard stainings and molecular biology techniques should be available, as well as several light microscopes and a computer-based histomorphometric analysis system (e.g. Aho et al, 2004;Meretoja et al, 2006;Puska et al, 2003;Silva Nykänen et al, 2011).…”

“…Since the mid-1990s, biodegradable polymer composites appear to have been studied for the applications of tissue engineering Meretoja et al, 2006;Middleton & Tipton, 2000;Törmälä, 1992;Wang, 2003). In these, the typical matrix polymers are polylactide (PLA), polycaprolactone (PCL), polypropylenefumarate (PPF) or any of their copolymers.…”

“…However, the biodegradable composites containing bioactive compounds are osteoconductive and easy to handle. Therefore, they are very suitable as bone grafting substitutes for small cancellous bone or cartilage defects Meretoja et al, 2006;Wang, 2003). Some years ago, Aho et al reported one injectable biodegradable composite that contains particles of bioactive glass embedded in poly(caprolactone-co-D,L-lactide) matrix.…”