Restricted cell functions on micropillars are alleviated by surface-nanocoating with amino groups

Area of Science:

• Biomaterials Science
• Cell Biology
• Surface Chemistry

Background:

• Biomaterial surface topography and chemistry influence cell behavior.
• Sharp microstructures on titanium can trigger detrimental osteoblast phagocytosis.
• Chemical modification of biomaterials is a strategy to improve cell response.

Purpose of the Study:

• To investigate if plasma polymerized allylamine (PPAAm) nanocoating can mitigate negative effects of microtopography on osteoblast physiology.
• To assess the impact of PPAAm on osteoblast interaction with micropillars.
• To evaluate PPAAm's influence on osteoblast gene expression and intracellular calcium signaling.

Main Methods:

• In vitro study using osteoblasts cultured on titanium micropillars.
• Surface modification with plasma polymerized allylamine (PPAAm).
• Assessment of cell interaction, mRNA expression (collagen type I, osteocalcin, fibronectin), and calcium ion (Ca2+) mobilization.

Main Results:

• PPAAm coating enhanced osteoblast interaction with micropillars within 30 minutes.
• Reduced decrease in mRNA expression of key osteogenic genes (collagen type I, osteocalcin, fibronectin) after 24 hours.
• Osteoblasts on PPAAm-coated micropillars exhibited increased activity and sensitivity, with significant Ca2+ mobilization upon ATP stimulation.

Conclusions:

• PPAAm nanocoating effectively attenuates negative microtopography-induced changes in osteoblast physiology.
• Enhanced cell surface contact and function on PPAAm-modified surfaces are critical for osteoblast performance.
• This approach holds promise for improving implant osseointegration by optimizing the biomaterial-cell interface.