A Dual Receptor and Reporter for Multi-Modal Cell Surface Engineering

Abstract

The rapid development of new small molecule drugs, nanomaterials, and genetic tools to modulate cellular function through cell surface manipulation has revolutionized the diagnosis, study, and treatment of disorders in human health. Since the cell membrane is a selective gateway barrier that serves as the first line of defense/offense and communication to its environment, new approaches that molecularly engineer or tailor cell membrane surfaces would allow for a new era in therapeutic design, therapeutic delivery, complex coculture tissue construction, and in situ imaging probe tracking technologies. In order to develop the next generation of multimodal therapies, cell behavior studies, and biotechnologies that focus on cell membrane biology, new tools that intersect the fields of chemistry, biology, and engineering are required. Herein, we develop a liposome fusion and delivery strategy to present a novel dual receptor and reporter system at cell surfaces without the use of molecular biology or metabolic biosynthesis. The cell surface receptor is based on bio-orthogonal functional groups that can conjugate a range of ligands while simultaneously reporting the conjugation through the emission of fluorescence. We demonstrate this dual receptor and reporter system by conjugating and tracking various cell surface ligands for temporal control of cell fluorescent signaling, cell-cell interaction, and tissue assembly construction.

Non‐Covalent Assembly Method that Simultaneously Endows a Liposome Surface with Targeting Ligands, Protective PEG Chains, and Deep‐Red Fluorescence Reporter Groups

“…Ideally, surface functionalization should be done after liposome fabrication and payload incorporation. Most studies that decorate the surface of liposomes use covalent conjugation chemistry, and although useful targeted systems have been developed, the bimolecular reactions are relatively slow and it is hard to ascertain if and when they have reached completion . This is potentially problematic because it leaves reactive groups on the liposome surface that could abrogate selective targeting, thus requiring an additional chemical capping step .…”

Scaffold Free Bio-orthogonal Assembly of 3-Dimensional Cardiac Tissue via Cell Surface Engineering

“…1). The interfacial oxime reaction is fast, chemoselective, occurs at physiological conditions (37 °C, pH 7) and requires no catalyst272829. Furthermore, the resulting oxime bond has no side reactions with biomacromolecules, is bio-orthogonal and therefore does not interfere with native biological processes30.…”

“…These tissues may be used for many applications including drug screening and as models for disease and infection as well as eventual cardiac patch in vivo applications. Many different cell types including stem cells may be used with the strategy and the inter cell click ligation is compatible with microfluidic and 3D printing technologies2324252627282930. We believe the combination of liposome fusion, bio-orthogonal chemistry and cell surface engineering to tailor cell surfaces will have a significant impact on autocrine and paracrine signaling studies and for the development and evaluation of tissues for drug screening and therapeutic organ on a chip based biotechnology applications4041424344.…”

Programming Cell-Cell Interactions through Non-genetic Membrane Engineering

“…Fibroblasts were first modified with a hydrazone-coupled ligand, and then that ligand was exchanged in situ for an oxyamine-conjugated RGD peptide. These RGD-functionalized fibroblasts were then able to recognize and adhere to other integrin-expressing fibroblasts, enabling the formation of tissue microlayers in vitro (Luo et al, 2015). …”