Cellular delivery of antibodies: effective targeted subcellular imaging and new therapeutic tool

Abstract

It is already more than a century since the pioneering work of the Nobel Laureate Ehrlich gave birth to the side chain theory1, which helped to define antibodies and their ability to target specific biological sites. However, the use of antibodies is still restricted to the extracellular space due to the lack of a suitable delivery vehicle for the efficient transport of antibodies into live cells without inducing toxicity. In this work, we report the efficient encapsulation and delivery of antibodies into live cells with no significant loss of cell viability or any deleterious affect on the cell metabolic activity. This delivery system is based on poly(2-(methacryloyloxy)ethyl phosphorylcholine)-block-(2-(diisopropylamino)ethyl methacrylate), (PMPC-PDPA), a pH sensitive diblock copolymer that self-assembles to form nanometer-sized vesicles, also known as polymersomes, at physiological pH. These polymersomes can successfully deliver relatively high antibody payloads within live cells. Once inside the cells, we demonstrate that these antibodies can target their epitope by immune-labelling of cytoskeleton, Golgi, and transcription factor proteins in live cells. We also demonstrate that this effective antibody delivery mechanism can be used to control specific subcellular events, as well as modulate cell activity and pro-inflammatory process.

Endocytosis at the nanoscale

“…Furthermore effective intracellular delivery can open new avenues for research by extending to other bioactive molecules such as drugs and proteins to the ''otherwise unreachable'' intracellular target as we have recently proposed. 376 Similarly, understanding the mechanistics of nanoparticle endocytosis is crucial for controlling nanoparticle pharmacokinetics and toxicity. Many traditional types of nanoparticles (such as carbon nanotubes, quantum dots and gold nanoparticles) have generated controversial toxicological studies and there is still a debate to whether they are a viable option for biomedical applications or not.…”

Intracellular Delivery and Trafficking Dynamics of a Lymphoma-Targeting Antibody–Polymer Conjugate

“…Fluorescence imaging has been shown to be a powerful tool for following the intracellular trafficking of biomacromolecules. For example, Massignani et al used subcellular imaging techniques to measure the trafficking kinetics of polymersomes from endocytosis to endosomal trafficking and cytosolic release. In other studies, Low and co-workers , employed ratiometric fluorescence techniques to characterize the pH of folate-driven trafficking through endosomes.…”

Polymersome‐Loaded Capsules for Controlled Release of DNA

“…The polymersomes are used to load a model therapeutic molecule, plasmid DNA (pDNA), which can be readily incorporated in polymersomes comprising PDPA 33. Nanostructures using PDPA have been used extensively for cell tracking36, 37 and cytosolic delivery applications,28, 33, 37, 38 and have shown minimal effect on cell viability 28, 33, 34, 39, 40…”