Title : From conjugation chemistry to antibody-targeted nanoformulations: Diagnostic and therapeutic applications
Abstract:
Bis-aryl haloacetamide (BisHalide) approach has been designed to address limitations experienced with current protein conjugation chemistries, as well as enabling the opportunity to develop novel antibody-conjugate modalities. This chemistry incorporates well-established thiol reactive halo-acetamide chemistry into an aryl scaffold, to deliver a unique disulfide re-bridging platform. We have deployed these linkers, moving them beyond their conventional scope, towards the development of novel antibody-nanoparticle conjugates.
Using traditional conjugation methods to produce antibody-targeted nanoparticles (NPs) has yielded limited control over antibody binding orientation and structural stability. Although these NPs have demonstrated proof of concept, they lack uniformity, reproducibility between batches, and stability, which hinders their clinical development.
To address these issues, BisHalide approach was adopted to construct Ab-immobilised NPs site-specifically. Initially, the conjugation of atezolizumab (anti-PDL1 antibody) with polymeric NPs was achieved using BisHalide rebridging chemistry, followed by click chemistry (NP-Fab BisHalide Ab and NP-Fc BisHalide Ab). For comparison, NPs created with conventional methods were also included. Flow cytometry and confocal microscopy were used to assess the targeted NPs (loaded with a fluorescent dye) for cellular binding and uptake. Results showed that NP-Fab BisHalide Ab and NP-Fc BisHalide Ab bound to and were taken up by EMT6 cells 19-fold and 13-fold more effectively, respectively. Overall, this work introduces a straightforward conjugation method that can be used to actively target NPs with various therapeutic antibodies approved for different malignancies.
