Surface Coating of Poly-d-l-Lactide/Nano-Hydroxyapatite Composite Scaffolds for Dexamethasone-Releasing Function and Wettability Enhancement

Biodegradable polymeric nano-composite scaffolds have recently attracted considerable attention in curing bone deficiencies resulting from fractures or traumas. In this article, the latest progress in fabrication and characterization of poly-D-L-lactide/nano-hydroxyapatite (PDLLA/nano-HA) composite scaffolds, with poly (ethylene glycol) (PEG)-coating and dexamethasone (Dex)-releasing for bone tissue engineering is presented. For the design of drug release scaffolds, some aspects related to the choice of polymer matrix, bioactive inclusions, drug release coatings, and fabrication techniques are firstly reviewed. A PEG-based coating method was subsequently developed to modify a biodegradable polymeric nano-composite scaffold in providing a drug release function with improved wettability. The changes of water contact angle of the scaffolds before and after PEG/Dex coating were measured and the drug release function of the PEG/Dex coating was studied. The experimental findings showed that the proposed coating method was effective in enhancing the wettability and in controlling the early stage of drug release of the PDLLA/nano-HA composite scaffold.