Published online Apr 26, 2015. doi: 10.4252/wjsc.v7.i3.657
Peer-review started: July 29, 2014
First decision: September 28, 2014
Revised: December 10, 2014
Accepted: December 29, 2014
Article in press: December 31, 2014
Published online: April 26, 2015
Processing time: 268 Days and 9 Hours
AIM: To improve osteogenic differentiation and attachment of cells.
METHODS: An electronic search was conducted in PubMed from January 2004 to December 2013. Studies which performed smart modifications on conventional bone scaffold materials were included. Scaffolds with controlled release or encapsulation of bioactive molecules were not included. Experiments which did not investigate response of cells toward the scaffold (cell attachment, proliferation or osteoblastic differentiation) were excluded.
RESULTS: Among 1458 studies, 38 met the inclusion and exclusion criteria. The main scaffold varied extensively among the included studies. Smart modifications included addition of growth factors (group I-11 studies), extracellular matrix-like molecules (group II-13 studies) and nanoparticles (nano-HA) (group III-17 studies). In all groups, surface coating was the most commonly applied approach for smart modification of scaffolds. In group I, bone morphogenetic proteins were mainly used as growth factor stabilized on polycaprolactone (PCL). In group II, collagen 1 in combination with PCL, hydroxyapatite (HA) and tricalcium phosphate were the most frequent scaffolds used. In the third group, nano-HA with PCL and chitosan were used the most. As variable methods were used, a thorough and comprehensible compare between the results and approaches was unattainable.
CONCLUSION: Regarding the variability in methodology of these in vitro studies it was demonstrated that smart modification of scaffolds can improve tissue properties.
Core tip: Currently, special attention has been directed to the design of new scaffolds by adding bioactive molecules and nanoparticles. “Smart scaffolds” in bone tissue engineering not only act as cell delivery materials, but they are also responsive to their environment and therefore stem cells are more likely to attach, proliferate and differentiate on them. These scaffolds can be fabricated by adding either of growth factors, extracellular matrix proteins or nanoparticles to the bone substitutes using various techniques. These modifications can enhance the in vitro response of bone scaffolds toward cells.