Three-dimensional microcarrier culture enhances secretome particle yield of human umbilical cord mesenchymal stem cells

Abstract

Human umbilical cord–derived mesenchymal stem/stromal cell (UC-MSC) secretome represents a promising cell-free approach for regenerative therapy; however, achieving a high-potency and a high-yield secretome in sufficient quantities remains a major challenge. This study compares conventional 2D monolayer culture with a 3D microcarrier-based system to evaluate their effects on secretome yield and characteristics. Secretome profiling included analysis of extracellular vesicle (EV)-related gene expressions (RAB27A, RAB27B, and RAB7A), nanoparticle concentration, and size distribution using nanoparticle tracking analysis (NTA). The results showed that RAB gene expression was reduced in the 3D system (0.52–0.75-fold relative to 2D), along with decreased cell proliferation. Despite this downregulation and a concurrent reduction in cellular proliferation, NTA revealed a higher particle concentration in 3D cultures (1.74 × 109 particles/mL) compared to 2D (7.30 × 108 particles/mL), with a broader size distribution. Although the 3D microcarrier culture limited UC-MSC expansion, it resulted in a higher concentration of extracellular vesicle-sized particles, supporting its potential as a platform for scalable secretome production.