Complex Stimuli Induced by Surface Discharge Method Enable Minimally Invasive and High-Efficiency Macromolecule Delivery Into Chlamydomonas reinhardtii

Abstract

Intracellular delivery of macromolecules into microalgae has been constrained by rigid cell walls. This study presents a high-efficiency, high-viability method for delivering macromolecules into Chlamydomonas reinhardtii using surface discharge plasma. At a nominal voltage of 25 kV, which produced a favorable balance between delivery efficiency and cell viability, the method achieved > 40% efficiency for 250 kDa FITC-dextran while maintaining > 80% viability. Under the same conditions, 2 MDa FITC-dextran was also delivered. Orthogonal cross-sectional analysis confirmed intracellular cargo localization. Delivery results from cellular responses to plasma-induced complex stimuli; the ~60% reduction highlights endocytosis as a major pathway, whereas the remaining fraction may involve multifaceted processes such as transient membrane permeabilization. This integrated approach enables minimally invasive macromolecule entry into microalgae.