LAUSR

Design smart scaffolds to reduce administration dosage under the premise of functional healing of bone defects to avoid the severe side effects associated with BMP-2 treatments is one of essential goals in bone tissue engineering. Here, we report a novel biodegradable PLGA/PSBMA composite as the scaffold for bone tissue engineering. The introduction of zwitterionic PSBMA component can alter the intrinsic burst degradation behavior of PLGA and enable a sustained degradation of the scaffold over the time. The PLGA/PSBMA scaffold can sequester rhBMP-2 and enable a sustained release of the sequestered rhBMP-2 with preserved bioactivity. Furthermore, PLGA/PSBMA scaffolds was able to guide robust healing of critical-sized non-union calvarial defect (5-mm) at ultra-low dose of 400 ng/scaffold, at which level successful healing of critical-sized bone defect has never been reported. These findings not only provide the PLGA/PSBMA scaffolds as novel high-efficiency rhBMP-2 delivery vehicles for bone tissue engineering, the concept of utilizing the material which is capable of maintaining the bioactivity of the proteins in the preparation of scaffolds may open a new avenue for the design of smart scaffolds/vehicles for high-efficiency protein/bioactive drug therapies.