Preparation and characterization of bovine serum albumin nanoparticles modified by Poly-l-lysine functionalized graphene oxide for BMP-2 delivery

The development of bioactive carrier with controlled delivery of Bone morphogenetic protein (BMP-2) is an important part in bone regeneration. Our study fabricated novel modified nanomaterials based on poly-l-lysine functionalized graphene oxide (GO-PLL) and explore its potential applications for BMP-2 delivery. GO-PLL was used to modify BMP-2 encapsulated bovine serum albumin (BSA) nanoparticles (GO-PLL/BMP-2) by self-assembling technology. The physiochemical and biological properties of GOPLL modified BSA nanoparticles were investigated in vitro. Additionally, rabbit calvarial bone defects were created to investigate bone formation ability in the presence of GO-PLL/BMP-2 loaded alginate/gelatin scaffolds. The results suggested BSA particles were spatially interacted with GO-PLL complexes by strong electrostatic attraction. When compared with BMP-2 encapsulated BSA nanoparticles, a pronounced decrease in BMP-2 gentle release was observed in the presence of GO-PLL/BMP-2 nanoparticles, and extended to over 14-day release periods. More importantly, GO-PLL/BMP-2 nanoparticles significantly enhanced alkaline phosphatase activity (ALP) and matrix mineralization, and exhibited favorable bone formation ability when loaded into alginate/gelatin scaffolds. These results demonstrated that PLL functionalized GO complexes are considered as appropriate delivery system for BSA modification, and have great potential for BMP-2 delivery in bone regeneration.CO 2022 Published by Elsevier Ltd. This is an open access article under the CC BY-NC-ND license (http:// creativecommons.org/licenses/by-nc-nd/4.0/).