Recently, Binghamton University, together with Nanjing Drum Tower Hospital, Affiliated Hospital of Medical School, Nanjing Regenecore Biotechnology Co., Ltd. and Harvard Medical School, jointly published the article "chimeric nanobody modified liposomes by self assembly" on Nature Nanotechnology (if 38.3), an international top journal in the field of nanotechnology. A new preparation method of immunoliposomes is reported. The core technology of this method is to design chimeric nanobodies that can be automatically assembled into the bilayer of liposomes, realizing the one-step preparation of immunoliposomes. The preparation scheme of immunoliposomes reported in this article directly hits the pain point of the current chemical modification method, and is expected to bring a qualitative leap to the industrialization of immunoliposomes. The chimeric nanobody targeting HER2 prepared in this paper has significantly improved the killing of cancer cells, and significantly prolonged the survival time of mice. It provides a new idea for targeted drug delivery and tumor clinic.

Chimeric nanobody (CNB) is composed of Nb targeting human epidermal growth factor receptor 2 (HER2), flexible peptide linker and human single transmembrane domain (STMD). After a series of preparation conditions optimization, lipids, drugs and CNB can be efficiently and automatically assembled into high-yield and high-purity immunoliposomes (CNB LP). The study showed that 64% of the drug loading could be encapsulated into 100 nm liposomes, and up to 2500 CNBS could be anchored on the liposome membrane under mild conditions without the influence of steric hindrance. Among them, the integration of HER2 targeting nanobody endows liposomes with targeting. Because of its high affinity (up to PM level), high stability, low immunogenicity and extremely small size (molecular weight is only one tenth of traditional monoclonal antibody), nanobody makes immunoliposomes successfully prepared, which helps drug loaded liposomes successfully target tumor cells.

The traditional chemical modification method for the preparation of immunoliposomes is very expensive because of its complex modification. The complex preparation process leads to the continuous loss of payload. The multi-step preparation conditions seriously affect the targeting activity, and the quality difference between batches cannot be controlled. At present, the industrialization challenge has not been effectively solved, so the large-scale production of immunoliposomes is very hampered, and the development of its application value is also very limited. The preparation principle of self-assembled immunoliposomes is the automatic assembly of liposomes, drug loads and chimeric nanobodies based on their biocompatibility. This scheme solves the disadvantages of the current chemical modification method, and is even expected to directly carry out large-scale production and development based on the current biological product production pipeline, showing broad prospects for industrial production.

The anti-tumor activity of CNB LP in HER2 overexpressing cell lines was significantly enhanced, and the therapeutic effect could be increased by 3.3 to 13.6 times, respectively; In the animal model (SK-BR-3 orthotopic model) experiment, the tumor volume of CNB LP group was 3.5 times and 1.7 times smaller than that of the two control groups, and the tumor weight of CNB LP and LP groups was 8.6 times and 4.6 times lighter than that of the control group, respectively;. CNB LP loaded with 5FU could prolong the median survival time of SK-BR-3 tumor bearing mice from 28 days to 56 days. In addition, the authors also studied the subcutaneous model of NCI-N87. The tumor volume of NCI-N87 treated with drug loaded CNB LP was 10.4 times, 5.6 times and 1.6 times that of the three control groups, respectively. This study provides a new idea for targeted drug delivery, which is expected to be applied in clinical tumor treatment.

Nanobodies are a new frontier, and based on their advantages of high affinity, high penetration, etc., they can be widely used in cancer treatment, detection, ADC, molecular imaging, nuclear medicine and other fields in the future.

To view more, please visit：https://www.nature.com/articles/s41565-024-01620-6