Rapamycin/sodium hyaluronate binding on nano-hydroxyapatite coated titanium surface improves MC3T3-E1 osteogenesis

Area of Science:

• Biomaterials Science
• Orthopedic Research
• Cell Biology

Background:

• Titanium (Ti) implant failure is often linked to poor surface biocompatibility, hindering osseointegration.
• Enhancing Ti surface topography is a strategy to improve osseointegration, but underlying mechanisms require elucidation.

Purpose of the Study:

• To investigate the impact of a modified Ti surface, incorporating nano-hydroxyapatite (HAp) and rapamycin (RA), on osteogenesis.
• To evaluate the role of sodium hyaluronate (SH) as an intermediate layer for sustained RA release and its effect on cell behavior.

Main Methods:

• Sequential acid-etching, alkali-heating, and HAp coating of Ti surfaces.
• Loading RA onto HAp-coated Ti using SH as an intermediate layer for controlled release.
• Assessing MC3T3-E1 cell vitality (MTT assay) and osteogenesis (ALP activity, mineralization, gene expression: OCN, OPN, Collagen-I, Runx2).

Main Results:

• The modified RA/SH-loaded nano-HAp Ti surface demonstrated no adverse effects on cell vitality.
• Significantly enhanced osteogenesis of MC3T3-E1 cells was observed on the modified Ti surface in vitro.
• Osteogenesis correlated with mammalian target of rapamycin (mTOR) phosphorylation induced by RA.

Conclusions:

• The developed modified Ti surface is biocompatible and promotes osteogenesis, showing promise for enhancing osseointegration.
• The findings highlight the potential of RA/SH-loaded nano-HAp coatings for developing improved titanium-based dental implants.
• Further research is needed to fully elucidate the mechanism linking RA-induced mTOR phosphorylation and enhanced osteogenesis.