Guanidine-modified albumin-MMAE conjugates with enhanced endocytosis ability

Abstract

Aiming to address the insufficient endocytosis ability of traditional albumin drug conjugates, this paper reports elegant guanidine modification to improve efficacy for the first time. A series of modified albumin drug conjugates were designed and synthesized with different structures, including guanidine (GA), biguanides (BGA) and phenyl (BA), and different quantities of modifications. Then, the endocytosis ability and in vitro/vivo potency of albumin drug conjugates were systematically studied. Finally, a preferred conjugate A4 was screened, which contained 15 BGA modifications. Conjugate A4 maintains spatial stability similar to that of the unmodified conjugate AVM and could significantly enhance endocytosis ability (p*** = 0.0009) compared with the unmodified conjugate AVM. Additionally, the in vitro potency of conjugate A4 (EC₅₀ = 71.78 nmol in SKOV3 cells) was greatly enhanced (approximately 4 times) compared with that of the unmodified conjugate AVM (EC₅₀ = 286.00 nmol in SKOV3 cells). The in vivo efficacy of conjugate A4 completely eliminated 50% of tumors at 33 mg/kg, which was significantly better than the efficacy of conjugate AVM at the same dose (P** = 0.0026). In addition, theranostic albumin drug conjugate A8 was designed to intuitively realize drug release and maintain antitumor activity similar to conjugate A4. In summary, the guanidine modification strategy could provide new ideas for the development of new generational albumin drug conjugates.

Keywords:

• Albumin drug conjugates
• guanidine modified
• endocytosis ability
• improve efficacy

Author contributions

M.C., X.Z. and D.X. designed, supervised the experiments. X.Z. provided fundings. C.Y., F.X., and X.X. conducted the experiments and analyzed the experimental data. C.Y. wrote the original draft. M.C., X.Z. and D.X. proofreading the manuscript. All authors have read and agreed to the published version of the manuscript and agreed to be accountable for all aspects of the work.

Date availability statement

The authors confirm that the data supporting the findings of this study are available within the article [and/or] its supplementary materials.

Disclosure statement

No potential conflict of interest was reported by the authors.

Ethics approval statement

All institutional and national guidelines for the care and use of laboratory animals were followed. The animal use protocol has been reviewed and approved by Yicon (Beijing) Biomedical Technology, Inc. IACUC under the approval No. YK-2022-001. And the authors will consciously abide by the ethical principles of The ARRIVE guidelines 2.0.

The mice were used to study the antitumor effect of the preparation. All animals were housed in a specific pathogen free environment. Each mouse feeding cage contained 3 mice, with an ambient temperature of 18–22 °C, relative humidity of 40–60%, light (12 h light/dark cycle) and were free access to diet. At the end of study, the pain and discomfort caused to mice will be subjected to general anesthesia through intraperitoneal injection, with pentobarbital sodium (80 mg/kg).

Additional information

Funding

This work was funded by the Chinese National Natural Science Foundation (Grant Nos. 82273854).