Liposomes modified with a multivalent glutamic hexapeptide: A novel and effective way to promote bone targeting

It is well known that bone-related diseases are difficult to treat due to the relatively low blood flow. Therefore, targeting the delivery of drugs to bone may not only improve the therapeutic effect but also reduce the dose. To prepare liposomes, a series of novel multivalent glutamic hexapeptide derivatives were designed and synthesized as liposome ligands, which can effectively deliver paclitaxel (PTX) to bone. The liposomes were prepared and their encapsulation efficiency, particle size, stability, zeta potential, hemolysis, and release behavior were characterized. The results indicated that the coated liposomes, PTX-Glu6₁ -Lip, PTX-Glu6₂ -Lip, PTX-Glu6₃ -Lip, and PTX-Glu6₅ -Lip, showed remarkable bone-targeting activity. Compared with the other coated liposomes, PTX-Glu6₅ -Lip showed prominent targeting ability and anti-bone metastasis activity on the basis of in vitro and in vivo evaluations. Our study may contribute to the field of design of bone-targeting drugs.