# Light‐Responsive Surface Topographies Modulate Macrophage Immune Responses Through Dynamic Mechanical Cues

## TL;DR

This paper shows how light-controlled surfaces can change macrophage behavior, offering new ways to control immune responses for regenerative medicine.

## Contribution

The study introduces light-responsive liquid crystal polymer films that dynamically modulate macrophage immune responses through reversible topographies.

## Key findings

- Grooves on light-responsive surfaces trigger mixed inflammatory and anti-inflammatory macrophage responses.
- Pillar-shaped topographies maintain an anti-inflammatory macrophage profile without broad activation.
- Dynamic topographies induce distinct membrane morphologies, including migration-associated blebbing and lamellipodia formation.

## Abstract

Understanding macrophage phenotype regulation by mechanical stimuli is a promising way to elucidate the body's inflammatory response and design new therapies. However, creating dynamic interfaces that allow precise, real‐time, and reversible control over mechanical cues remains a challenge. In this study, we report the immunomodulatory effects of dynamic liquid crystal (LC) polymer films on in vitro macrophage responses. By utilizing reversible light‐induced LC surface topographies, we generate dynamic mechanical stimuli on cells during topography formation and removal, enabling on‐demand and reversible reprogramming of cell behavior. Our findings reveal a strong topographical shape‐dependent cell response by examining the effects of flat, pillared, and grooved LC films on THP‐1‐derived macrophages. A strong increase in both pro‐ and anti‐inflammatory markers is observed on grooves, while pillars maintain the anti‐inflammatory profile without broad activation. Macrophages on LC film‐generated topographies furthermore present distinct cytokine expression profiles. Notably, light‐induced grooves triggered a stronger pro‐remodeling cellular response, while pillars appeared to exert an inhibitory effect on macrophage activation. The dynamic topographies remarkably induced distinct changes in the macrophage membrane morphology, triggering migration‐associated blebbing of the cell membrane in all cases except for grooves that promoted an increased degree of lamellipodia and filopodia formation. Overall, these results demonstrate that light‐responsive LC surfaces provide a controllable platform for topography‐dependent and adaptive immune modulation, opening opportunities for rational design of immunoregulatory scaffolds that exploit macrophage plasticity for regenerative medicine.

This work introduces light‐responsive liquid crystal polymer films that generate dynamic, reversible topographies to modulate macrophage immune responses. By switching surface features on demand, we reveal macrophage plasticity, morphological adaptation, and mechanical memory. Grooves elicit strong mixed phenotypes, while pillars maintain anti‐inflammatory profiles, offering a controllable platform for adaptive immunomodulation in regenerative medicine.