Implant surface physicochemistry affects keratinocyte hemidesmosome formation

Area of Science:

• Biomaterials Science
• Surface Chemistry
• Oral Biology

Background:

• Implant surface properties influence osseointegration and soft tissue attachment.
• Understanding the role of surface functional groups in promoting oral keratinocyte behavior is crucial for improving implant longevity.
• Hemidesmosomes (HDs) are key for stable soft tissue integration with implants.

Purpose of the Study:

• To investigate how common biological functional groups (amine, hydroxyl, methyl) on a model surface affect oral keratinocyte (OKs) proliferation and hemidesmosome (HD) formation.
• To identify specific surface physicochemical properties that stimulate HDs for enhanced soft tissue attachment.
• To correlate surface chemistry with protein adsorption and subsequent cellular response.

Main Methods:

• Functionalization of glass surfaces with amine (NH2), hydroxyl (OH), and methyl (CH3) groups via silanization.
• Characterization of surface modifications using X-ray photoelectron spectroscopy and water contact angle measurements.
• Assessment of protein adsorption (BSA, fibrinogen) and quantification of OKs proliferation and HD expression (collagen XVII, integrin β4).

Main Results:

• Plasma-cleaned surfaces were most hydrophilic; CH3 surfaces were most hydrophobic; OH surfaces were most hydrophilic among functionalized groups.
• Hydroxyl (OH) functionalized surfaces demonstrated the highest OKs proliferation and HD expression.
• The cellular response on OH surfaces did not directly correlate with adsorbed protein amount or thickness.

Conclusions:

• Surface modification with hydroxyl groups is a promising strategy to enhance oral keratinocyte proliferation and hemidesmosome formation.
• Specific surface physicochemical features, particularly hydroxyl groups, are critical for promoting robust soft tissue attachment to implant surfaces.
• These findings offer insights into designing biomaterials for improved implant performance and longevity through enhanced soft tissue integration.