# 3D printing combined with pH-induced 4D printed iron(III)-oxidized starch gels for controlled iron delivery and enhanced iron supplementation.
> pH応答性4Dプリント酸化デンプン鉄ゲルによる鉄の制御放出と鉄欠乏性貧血への応用


## Abstract

To address iron deficiency anemia (IDA), a pH-triggered 4D-printed ferric oxidized starch gel system (4D-FeOMS) was constructed by integrating hot-extrusion 3D printing with stimulus-responsive structural transformation. Iron ions were coordinated within oxidized starch networks through ionic crosslinking. Rheological and spectroscopic characterization (FTIR, XPS) confirmed enhanced molecular entanglement and network uniformity in 4D-FeOMS relative to conventional 3D-printed counterparts. In vitro digestion assays demonstrated gastric retention of iron (release below 30%) followed by rapid liberation exceeding 85% in the proximal small intestine. In IDA mouse models, 4D-FeOMS restored hematological and biochemical indices, recovered organ iron stores by more than 94.6%, and elevated antioxidant enzyme activity, surpassing both iron salt controls and 3D-FeOMS. Mechanistic analysis indicated that hepcidin expression was modulated and ferritin/transferrin levels were regulated, collectively promoting systemic iron transport. The 4D-FeOMS formulation with 10% iron addition showed optimal complexation and supplementation performance.

### Mechanism

4D-FeOMS modulates hepcidin expression and regulates ferritin/transferrin levels to facilitate systemic iron transport; it also enhances antioxidant enzyme activity, collectively improving iron bioavailability in IDA conditions.

## Bibliographic

- **Authors**: Qiu Z, Guo Q, Lv J, Chen L
- **Journal**: Carbohydr Polym
- **Year**: 2025 (2025-10-15)
- **PMID**: [40733848](https://pubmed.ncbi.nlm.nih.gov/40733848/)
- **DOI**: [10.1016/j.carbpol.2025.123933](https://doi.org/10.1016/j.carbpol.2025.123933)
- **Study type**: animal study
- **Delivery route**: animal model
- **Effect reported**: positive

## Delivery context

This study is at the animal-experiment stage. 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 documented in the Consumer Affairs Agency accident database and are not recommended).

## Safety notes

This study is at the animal-experiment stage. 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 documented in the Consumer Affairs Agency accident database and 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)

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> **Cite as**: H2 Papers — PMID 40733848. https://h2-papers.org/en/papers/40733848
> **Source**: PubMed PMID [40733848](https://pubmed.ncbi.nlm.nih.gov/40733848/)