Si substituted hydroxyapatite nanorods on Ti for percutaneous implants

Area of Science:

• Biomaterials Science
• Tissue Engineering
• Surface Chemistry

Background:

• Percutaneous implants require osseointegration and a tight soft tissue seal.
• Enhancing fibroblast response and biosealing is crucial for implant success.

Purpose of the Study:

• To design and fabricate silicon-substituted hydroxyapatite (Si-HA) nanorods on titanium (Ti) substrates.
• To evaluate the effect of Si-HA nanorods on fibroblast behavior and soft tissue integration.
• To explore the mechanism of Si-HA nanorod formation and their surface characteristics.

Main Methods:

• Si-HA nanorods were synthesized using alkali-heat and hydrothermal treatments.
• Surface characteristics (phase, morphology, roughness, wettability) were compared between Si-HA and pure HA nanorods.
• In vitro fibroblast proliferation, fibrotic phenotype, and collagen secretion were assessed.
• In vivo skin response and epithelial down growth were evaluated.

Main Results:

• Si-HA nanorods released additional silicon (Si) and calcium (Ca) ions.
• Si-HA nanorods enhanced fibroblast proliferation, fibrotic phenotype, and collagen secretion in vitro.
• Si-HA nanorods reduced epithelial down growth in vivo compared to pure HA nanorods and Ti substrate.
• Surface characteristics were largely unchanged by Si substitution, but nanotopography and ion release were key factors.

Conclusions:

• Si-HA nanorods promote enhanced cellular response and biosealing due to ion release and nanotopography.
• Si-HA nanorods show potential as a coating to accelerate skin integration for percutaneous implants.
• This approach offers a promising strategy for improving the clinical performance of transcutaneous medical devices.