Composite clinoptilolite/PCL‐PEG‐PCL scaffolds for bone regeneration: In vitro and in vivo evaluation

The aim of this study was to prepare and characterize highly porous clinoptilolite/poly(ε-caprolactone)-poly (ethylene glycol)-poly(ε-caprolactone) (CLN/PCEC) composite scaffolds. Scaffolds with different clinoptilolite contents (10% and 20%) were fabricated with reproducible solvent-free powder compression/particulate leaching technique. The scaffolds have interconnective porosity in the range of 55% to 76%. CLN-PCEC scaffolds showed negligible degradation within 8 weeks and displayed less swelling and higher bioactivity than PCEC scaffolds. Presence of clinoptilolite improved the mechanical properties. Highest compressive strength (5.6 MPa) and modulus (114.84 MPa) were reached with scaffold group containing 20% CLN. In vitro protein adsorption capacity of the scaffolds was also higher for CLN-PCEC scaffolds. These scaffolds had 0.95 mg protein/g scaffold adsorption capacity and also higher osteoinductivity in terms of enhanced ALP, OSP activities and intracellular calcium deposition. Stoichiometric apatite deposition (Ca/P=1.686) was observed during cellular proliferation analysis with human fetal osteoblasts cells. Thus, it can be suggested that CLN-PCEC composite scaffolds could be promising carriers for enhancement of bone regeneration in bone tissue engineering applications.