# Isolation and Characterization of Marrow-Isolated Adult Multilineage Inducible (MIAMI) Cell-Derived Extracellular Vesicles Demonstrate Multifunctional Therapeutic Potential in Tissue Regeneration and Anti-Inflammatory Immunomodulation

## TL;DR

Marrow-isolated adult multilineage inducible (MIAMI) cell-derived extracellular vesicles (MIA-EVs) show strong regenerative and anti-inflammatory effects, making them promising for tissue repair and immune modulation in disease environments.

## Contribution

MIA-EVs are shown to have a conserved miRNA core and robust therapeutic potential under inflammatory and stress conditions, outperforming conventional MSC-EVs.

## Key findings

- MIA-EVs accelerate keratinocyte wound closure and suppress osteosarcoma cell proliferation in vitro.
- MIA-EVs maintain a conserved miRNA backbone across different conditions, enhancing stress resilience and immune reprogramming.
- MIA-EVs promote M2 macrophage polarization and show consistent regulatory identity compared to MSC-EVs.

## Abstract

What are the main findings?
MIAMI cells produce highly pure, exosome-enriched extracellular vesicles (MIA-EVs) with strong regenerative and immunomodulatory molecular signatures.MIA-EVs accelerate keratinocyte wound closure and suppress osteosarcoma cell proliferation in vitro.

MIAMI cells produce highly pure, exosome-enriched extracellular vesicles (MIA-EVs) with strong regenerative and immunomodulatory molecular signatures.

MIA-EVs accelerate keratinocyte wound closure and suppress osteosarcoma cell proliferation in vitro.

What is the implication of the main finding?
Their conserved regulatory identity under inflammatory and irradiation priming supports robust translational use in hostile disease environments.Compared with MSC-EVs, MIA-EVs amplify a conserved mesenchymal miRNA core into an expanded regulatory network that enhances stress resilience, regeneration, and immune reprogramming.

Their conserved regulatory identity under inflammatory and irradiation priming supports robust translational use in hostile disease environments.

Compared with MSC-EVs, MIA-EVs amplify a conserved mesenchymal miRNA core into an expanded regulatory network that enhances stress resilience, regeneration, and immune reprogramming.

Marrow-isolated adult multilineage inducible (MIAMI) cells are a subpopulation of mesenchymal stem/stromal cells (MSC) with enhanced self-renewal, multilineage plasticity, and anti-inflammatory properties, suggesting that their extracellular vesicles (MIA-EVs) may confer advantages over conventional MSC-EVs. MIAMI cells were transcriptionally profiled and expressed regenerative markers, including PDGFRB, CDX2, and TERT. We report the first successful isolation and characterization of MIA-EVs. EVs were isolated by ultracentrifugation and characterized by nanoparticle tracking analysis, transmission electron microscopy, flow cytometry, and surface markers. Cargo analysis identified growth factors (IGFBP-1, HGF, VEGF-D) and 19 highly expressed miRNA targeting survival, regenerative, and immune regulatory pathways. MIA-EVs were efficiently internalized, enhanced keratinocyte wound closure and suppressed osteosarcoma proliferation in vitro. Conditioned MIA-EVs reshaped pathway weighting without altering core regulatory identity, as a conserved 15-miRNA backbone persisted across naïve, irradiated, and cytokine-primed states. In contrast, a 9-miRNA core shared with MSC-EVs defined a basal mesenchymal framework, while MIA-EVs expanded regenerative, survival, and immune network connectivity. Similar to embryonic stem cell (ESC)-EVs, both MIA- and cytokine-primed EVs promoted M2 macrophage polarization, selectively upregulating IL1R2 and PPARG/STAT1, respectively. Meanwhile, MSC-EVs induced heterogeneous responses. These findings establish MIA-EVs as a conditioning-resistant, systems-regulated, cell-free platform with regenerative, immunomodulatory, and cytoprotective potential under hostile microenvironments.