# Effects of hydrogen-occluding-silica microparticles on wound repair and cell migratory behavior of normal human esophageal epitheliocytes.
> 水素内包シリカ微粒子がヒト正常食道上皮細胞の創傷修復および細胞遊走挙動に与える影響


## Abstract

This in vitro study examined how hydrogen-occluding silica microparticles (H-silica) affect cell migration and cytoskeletal dynamics, specifically F-actin, in normal human esophageal epithelial cells (HEEpiCs). At 100 ppm, cell migration was enhanced and microvillus formation was activated in scratch-assay conditions. Both 10 ppm and 100 ppm groups showed measurable wound closure at 48 and 72 hours, consistent with antioxidant-mediated repair. At concentrations of 300 ppm and above, elevated activated caspase-3 and an increased Bax/Bcl-2 ratio indicated apoptosis induction, particularly in scratched cells, suggesting concentration-dependent cytotoxicity. The fascin/tubulin ratio tended to rise across 100–600 ppm groups in both scratched and non-scratched conditions, implying that H-silica may promote fascin-driven cytoskeletal remodeling and potentially support cell proliferation at lower doses.

### Mechanism

At low concentrations, H-silica antioxidant activity promotes cell migration and fascin-mediated cytoskeletal remodeling; at high concentrations (≥300 ppm), caspase-3 activation and an elevated Bax/Bcl-2 ratio drive apoptosis, particularly in mechanically injured cells.

## Bibliographic

- **Authors**: Li Q, Tanaka Y, Miwa N
- **Journal**: Med Gas Res
- **Year**: 2018
- **PMID**: [30112167](https://pubmed.ncbi.nlm.nih.gov/30112167/)
- **DOI**: [10.4103/2045-9912.235128](https://doi.org/10.4103/2045-9912.235128)
- **PMC**: [PMC6070841](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6070841/)
- **Study type**: in vitro study
- **Delivery route**: in vitro
- **Effect reported**: mixed

## Delivery context

This is basic research at the cellular or molecular level. For human application, inhalation is the most promising delivery route, but inhalation carries explosion risk and concentration matters (empirical LFL of 10%; high-concentration devices are not recommended).

## Safety notes

This is basic research at the cellular or molecular level. For human application, inhalation is the most promising delivery route, but inhalation carries explosion risk and concentration matters (empirical LFL of 10%; high-concentration devices are not recommended).

See also:
- [Inhalation concentration and LFL / UFL](https://h2-papers.org/en/safety-notes/inhalation-concentration)
- [Consumer Affairs Agency accident cases](https://h2-papers.org/en/safety-notes/accident-cases)
- [Inhalation safety threshold lineage](https://h2-papers.org/en/safety-notes/lineage)

---

> **Cite as**: H2 Papers — PMID 30112167. https://h2-papers.org/en/papers/30112167
> **Source**: PubMed PMID [30112167](https://pubmed.ncbi.nlm.nih.gov/30112167/)