Chitosan/hydroxyapatite composite bone tissue engineering scaffolds with dual and decoupled therapeutic ion delivery: copper and strontium
Résumé
Therapeutic metal ions are a family of metal ions characterized by specific biological properties that
could be exploited in bone tissue engineering, avoiding the use of expensive and potentially problematic
growth factors and other sensitive biomolecules. In this work, we report the successful preparation and
characterization of two material platforms containing therapeutic ions: a copper(II)–chitosan derivative
and a strontium-substituted hydroxyapatite. These biomaterials showed ideal ion release profiles,
offering burst release of an antibacterial agent together with a more sustained release of strontium in
order to achieve long-term osteogenesis. We combined copper(II)–chitosan and strontium–hydroxyapatite
into freeze-dried composite scaffolds. These scaffolds were characterized in terms of morphology,
mechanical properties and bioactivity, defined here as the ability to trigger the deposition of novel calcium
phosphate in contact with biological fluids. In addition, a preliminary biological characterization using cell
line osteoblasts was performed. Our results highlighted that the combination of chitosan and hydroxyapatite
in conjunction with copper and strontium has great potential in the design of novel scaffolds. Chitosan/HA
composites can be an ideal technology for the development of tissue engineering scaffolds that deliver a
complex arrays of therapeutic ions in both components of the composite, leading to tailored biological
effects, from antibacterial activity, to osteogenesis and angiogenesis