Bone regeneration using photocrosslinked hydrogel incorporating rhBMP-2 loaded 2-N, 6-O-sulfated chitosan nanoparticles.
Although rhBMP-2 has excellent ability to accelerate the repair of normal bone defects, limitations of its application exist in the high cost and potential side effects. This study aimed to develop a composite photopolymerisable hydrogel incorporating rhBMP-2 loaded 2-N, 6-O-sulfated chitosan nanoparticles (PH/rhBMP-2/NPs) as the bone substitute to realize segmental bone defect repair at a low growth factor dose. Firstly rhBMP-2 loaded 2-N, 6-O-sulfated chitosan nanoparticles (rhBMP-2/NPs) were prepared and characterized by DLS and TEM. Composite materials, PH/rhBMP-2/NPs were developed and investigated by SEM-EDS as well as a series of physical characterizations. Using hMSCs as an in vitro cell model, composite photopolymerisable hydrogels incorporating NPs (PH/NPs) showed good cell viability, cell adhesion and time dependent cell ingrowth. In vitro release kinetics of rhBMP-2 showed a significantly lower initial burst release from the composite system compared with the growth factor-loaded particles alone or encapsulated directly within the hydrogel, followed by a slow release over time. The bioactivity of released rhBMP-2 was validated by alkaline phosphatase (ALP) activity as well as a mineralization assay. In in vivo studies, the PH/rhBMP-2/NPs induced ectopic bone formation in the mouse thigh. In addition, we further investigated the in vivo effects of rhBMP-2-loaded scaffolds in a rabbit radius critical defect by three dimensional micro-computed tomographic (μCT) imaging, histological analysis, and biomechanical measurements. Animals implanted with the composite hydrogel containing rhBMP-2-loaded nanoparticles underwent gradual resorption with more pronounced replacement by new bone and induced reunion of the bone marrow cavity at 12 weeks, compared with animals implanted with hydrogel encapsulated growth factors alone. These data provided strong evidence that the composite PH/rhBMP-2/NPs are a promising substitute for bone tissue engineering.
The State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai 200237, PR China; CSIRO Materials Science and Engineering, Bayview Avenue, Clayton, Victoria 3168, Australia; Key Laboratory for Ultrafine Materials of Ministry of Education, East China University of Science and Technology, Shanghai 200237, PR China.
Lingyan
L
Cao
CSIRO Materials Science and Engineering, Bayview Avenue, Clayton, Victoria 3168, Australia.
Jerome A
JA
Werkmeister
The State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai 200237, PR China; Key Laboratory for Ultrafine Materials of Ministry of Education, East China University of Science and Technology, Shanghai 200237, PR China.
Jing
J
Wang
CSIRO Materials Science and Engineering, Bayview Avenue, Clayton, Victoria 3168, Australia.
Veronica
V
Glattauer
CSIRO Materials Science and Engineering, Bayview Avenue, Clayton, Victoria 3168, Australia. Electronic address: Keith.McLean@csiro.au.
Keith M
KM
McLean
The State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai 200237, PR China; Key Laboratory for Ultrafine Materials of Ministry of Education, East China University of Science and Technology, Shanghai 200237, PR China; Engineering Research Center for Biomedical Materials of Ministry of Education, East China University of Science and Technology, Shanghai 200237, PR China.
Changsheng
C
Liu
D000818:Animals; D001672:Biocompatible Materials / Q000494:pharmacology; D001696:Biomechanical Phenomena / Q000187:drug effects; D055396:Bone Morphogenetic Protein 2 / Q000494:pharmacology*; D001861:Bone Regeneration / Q000187:drug effects*; D002113:Calcification, Physiologic / Q000187:drug effects; D002448:Cell Adhesion / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D048271:Chitosan / Q000031:analogs & derivatives* / Q000494:pharmacology; D002828:Choristoma / Q000473:pathology; D018920:Coculture Techniques; D019245:Compressive Strength / Q000187:drug effects; D003432:Cross-Linking Reagents / Q000494:pharmacology*; D018483:Diaphyses / Q000000981:diagnostic imaging / Q000187:drug effects / Q000473:pathology; D006801:Humans; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate / Q000494:pharmacology*; D007700:Kinetics; D008027:Light; D008297:Male; D051379:Mice; D009132:Muscles / Q000187:drug effects / Q000473:pathology; D053758:Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D010012:Osteogenesis / Q000187:drug effects; D011817:Rabbits; D011859:Radiography; D011994:Recombinant Proteins / Q000494:pharmacology; D013052:Spectrometry, X-Ray Emission; D013314:Stress, Mechanical; D016212:Transforming Growth Factor beta / Q000494:pharmacology*
C539268:2-N, 6-O-sulfated chitosan; D001672:Biocompatible Materials; D055396:Bone Morphogenetic Protein 2; D003432:Cross-Linking Reagents; D011994:Recombinant Proteins; D016212:Transforming Growth Factor beta; C499469:recombinant human bone morphogenetic protein-2; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate; D048271:Chitosan
BMP; Bone regeneration; Hydrogel; Nanoparticle