Abstract

Loading hydrogels with bioactive agents is an important method for expanding the functional application of hydrogels. However, how to improve the local administration and slow release of drugs from a hydrogel is a challenge when using hydrogels loaded with drugs. In this paper, we first developed adhesive liposomes (A-LIP) loaded with BMP-2. Then, we incorporated the A-LIP into PEG hydrogels based on the coordinated cross-linking principle of SH-PEG and Ag + , fabricating an injectable, antibacterial and self-healing multifunctional drug delivery system. The adhesive lipo-hydrogel (A-LIP-PEG) fabricated by mixing PEG hydrogels and adhesive liposomes can be locally injected into an osteoporotic fracture and bone marrow cavity, where A-LIP-PEG can release adhesive liposomes that adhere to the bone injury area and promote bone reconstruction. Based on the principle of electrostatic attraction, tissue nonspecific A-LIP were fabricated by grafting octadecylamine onto liposomes. Because of the coordination and cross-linking of thiolated polyethylene (SH-PEG) and Ag + , the A-LIP-PEG showed excellent injectability and self-healing properties; further, because of the presence of Ag + , the A-LIP-PEG showed effective inhibition of S. aureus and Escherichia coli . The liposomes released by the A-LIP-PEG were able to adhere to tissue. In vitro studies showed that A-LIP-PEG significantly promoted osteogenic differentiation and had no significant effect on cell proliferation. Compared with common lipo-hydrogel (LIP-PEG), the A-LIP-PEG had better tissue adhesion in vivo, which led to better osteogenic differentiation and faster local bone remodeling of osteoporotic fractures in rats. This research developed a novel hydrogel system with adhesive liposomes to expand the application of hydrogels.