# Surface Engineering of Natural Killer Cells with Lipid-Based Antibody Capture Platform for Targeted Chemoimmunotherapy

## TL;DR

This paper introduces a new method to engineer natural killer cells with antibodies for targeted cancer treatment without genetic modification.

## Contribution

A non-genetic, lipid-based platform for rapid and reversible functionalization of NK cells with therapeutic antibodies or ADCs.

## Key findings

- ACP-modified NK cells showed enhanced tumor recognition and cytotoxicity against HER2- and Trop-2-positive cancer cells.
- The platform supports multi-antigen targeting and tunable antibody loading, adapting to tumor heterogeneity and resistance.
- AC-NKs demonstrated immune activation through enhanced cancer cell engagement and CD107a upregulation.

## Abstract

Next-generation cancer immunotherapy increasingly combines tumor-targeting antibodies or antibody–drug conjugates (ADCs) with immune effector cells to enhance therapeutic precision. However, many existing approaches rely on genetic modification or complex manufacturing, limiting their clinical scalability and rapid deployment. To address this issue, we developed an antibody capture protein (ACP)-based surface engineering platform that enables the rapid, reversible, and non-genetic functionalization of NK cells with therapeutic antibodies or ADCs. This approach uses a DMPE-PEG-lipid conjugate to anchor thiolated protein A (ACP) to the NK cell membrane via hydrophobic insertion, thereby stably and selectively binding to the Fc region of IgG molecules. Using this strategy, we developed ACP-modified NK cells (AC-NKs) that can selectively capture therapeutic antibodies (trastuzumab (TZ), trastuzumab-emtansine (T-DM1), and sacituzumab (SZ)) pre-bound to each target antigen on tumor cells and induce antigen-specific cytotoxic responses. The resulting AC-NKs exhibited enhanced tumor recognition and cytotoxicity against HER2-positive and Trop-2-positive cancer cells in vitro. Compared with conventional combination therapies, AC-NKs enhanced immune activation, as demonstrated by effective delivery of cytotoxic agents, enhanced cancer cell engagement, and upregulation of CD107a expression. Notably, the system supports multiple antigen targeting and tunable antibody loading, enabling adaptation to tumor heterogeneity and resistant phenotypes. This platform might also provide a simple, scalable, and safe method for rapidly developing programmable immune cell therapies without genetic modification. Its versatility supports multi-antigen targeting and broad applicability across NK and T cell therapies, offering a promising path toward personalized, off-the-shelf chemoimmunotherapy.