Bioactive Inorganic and Organic Composite Materials for Bone Regeneration and Gene Delivery - Advanced Bioactive Inorganic Materials for Bone Regeneration and Drug Delivery - page 190

tissue-derived stem cells (ASCs). In comparison with the ASCs cultured
alone on BCP/PCL, early osteogenic differentiation of ASCs was induced by
either seeding ASCs on BCP/PCL-nHAp scaffolds or by coculturing with
HOBs; the combination of BCP/PCL-nHAp scaffold and HOBs resulted in
the synergistic enhancement of osteogenic gene expression. Moreover, it
was found that BCP/PCL-nHAp scaffolds induced early osteogenic differ-
entiation of ASCs through integrin-α2 and an extracellular signal-regulated
kinase (ERK) signaling pathway (Lu et al. 2012).
7.2.2 Composites of Bioactive Glass (BG) or Mesoporous
Bioactive Glass (MBG) and Polymers
Bioactive glass (BG) is another kind of inorganic material widely used in
bone tissue engineering. Mesoporous BG (MBG), as a new class of BG, was
first developed in 2004. Compared to traditional BG, MBG possesses a more
optimal surface area and a well-ordered nanochannel structure, whose in
vitro bioactivity is far superior than that of nonmesoporous BG (Figure 7.4)
(Wu, Zhang, Zhou, et al. 2011).
7.2.2.1 Particles
Poly(epsilon-caprolactone) (PCL)/bioactive glass (BG) nanocomposite
was fabricated using BG nanofibers (BGNFs) and compared with an
established composite fabricated using microscale BG particles. The
BGNFs were generated using sol-gel precursors via the electrospin-
ning process, chopped into short fibers, and then incorporated into the
PCL organic matrix by dissolving them in a tetrahydrofuran solvent.
The biological and mechanical properties of the PCL/BGNF compos-
ites were evaluated and compared with those of PCL/BG powder (BGP).
In vitro cell tests using the MC3T3 cell line demonstrated the enhanced
5 nm
50 nm
FIGURE 7.4
TEM image of the prepared MBG scaffolds. MBG scaffolds have a highly ordered mesopore-
channel structure.