Pyrophosphate-modified liposomes for bone-targeted delivery

Bone-related diseases and bone cancers remain challenging to treat due to limited targeted therapies and significant off-target side effects. This study presents the development of a bone-targeted liposomal formulation, termed Bone Binding Liposomes (BBL), functionalized with a pyrophosphate-cholesterol derivative to enhance binding to bone mineral (hydroxyapatite). Our experiments demonstrated the superior affinity of BBL compared to conventional Non-Binding Liposomes (NBL). Moreover, both formulations efficiently encapsulated a prototype drug and both exhibited comparable biocompatibility, both preserving the drug's physicochemical properties on elective target cells, macrophages. This targeted delivery system holds a potential for treating bone-related diseases, offering a means to improve targeted delivery and reduce off-target effects.