title: Drug delivery using composite scaffolds in the context of bone tissue engineering.
abstract: BACKGROUND
  Due to the disadvantages of the current bone autograft and allograft in many clinical condition in which bone regeneration is required in large quantity, engineered biomaterials combined with growth factors, such as bone morphogenetic protein-2 (BMP-2), have been demonstrated to be an effective approach in bone tissue engineering, since they can act both as a scaffold and as a drug delivery system to promote bone repair and regeneration.
  
  
  METHODS
  Recent advantages in the field of engineered scaffolds have been obtained from the investigation of composite scaffolds designed by the combination of bioceramics, especially hydroxyapatite (HA), and biodegradable polymers, such as poly (D,L-lactide-co-glycolide) (PLGA) and chitosan, in order to realize osteoconductive structures that can mimic the natural properties of bone tissue. Herein it is demonstrated that the incorporation of BMP-2 into different composite scaffolds, by encapsulation, absorption or entrapment, could be advantageous in terms of osteoinduction for new bone tissue engineered scaffolds as drug delivery systems and some of them should be further analyzed to optimized the drug release for future therapeutic applications.
  
  
  CONCLUSIONS
  New design concepts and fabrication techniques represent novel challenges for further investigations about the development of scaffolds as a drug delivery system for bone tissue regeneration.
authors.affiliation: Department of Surgery and Translational Medicine, University of Florence, Florence, Italy.
authors.forename: Cecilia
authors.initials: C
authors.lastname: Romagnoli
authors.affiliation: Department of Neurosciences, Psychology, Drug Area and Child Health, University of Florence, Florence, Italy.
authors.forename: Federica
authors.initials: F
authors.lastname: D'Asta
authors.affiliation: Department of Surgery and Translational Medicine, University of Florence, Florence, Italy.
authors.forename: Maria Luisa
authors.initials: ML
authors.lastname: Brandi
keywords: bone morphogenetic protein-2; bone tissue engineering; composite scaffold; drug delivery