Magnetic biopolymer nanogels via biological assembly for vectoring delivery of biopharmaceuticals

Biopolymer-based nanogels have great potential in the field of tissue regenerative medicine. In this work, a magnetic biopolymer nanogel via specific nucleobase pairing was developed for vectoring delivery of cell growth factors. The biopolymer based nanogels chitosan and heparin were established by the Watson-Crick base pairing between thymine and adenine via the hydrogen bonding. The magnetic biopolymer nanogels exhibit quick magnetic responsibility, which were fabricated by encapsulating superparamagnetic iron oxide nanoparticles. The potential applications of this magnetic nanogel on vectoring delivery of cell growth factors were confirmed by adsorption and release behaviors of bone morphogenetic protein 2 (BMP-2). The existence of heparin made the nanogel achieve a high loading efficiency of BMP-2, and the vectoring delivery of BMP-2 could be easily controlled by the external magnetic field. In vitro cytotoxicity tests demonstrated that incorporation of BMP-2 into this biopolymer nanogel through binding with heparin showed high efficiency to promote MG-63 cells' viabilities, in particular under a magnetic field, which suggested a promising future for cartilage and bone regeneration applications.