Submicron poly(L-lactic acid) pillars affect fibroblast adhesion and proliferation

Area of Science:

• Biomaterials Science
• Cell Biology
• Tissue Engineering

Background:

• Controlling cell adhesion and proliferation on synthetic polymers is crucial for tissue engineering scaffold development.
• The precise mechanisms by which surface topography influences cell response remain unclear.

Purpose of the Study:

• To investigate the effect of specific nanoscale surface topographies on human fibroblast adhesion and proliferation.
• To elucidate the role of focal complex (FX) and focal adhesion (FA) formation in mediating cell response to nanotopography.

Main Methods:

• Poly(L-lactic acid) surfaces were patterned with 400-nm and 700-nm pillars using replication molding.
• Human fibroblast adhesion and proliferation were quantified.
• Immunofluorescence was used to evaluate focal contacts, focal adhesions, and actin microfilaments.
• Scanning electron microscopy (SEM) was employed to observe cell-topography interactions.

Main Results:

• Initial fibroblast adhesion (<1 day) increased with nanotopography (400 nm > 700 nm > smooth).
• Fibroblast proliferation (>1 day) decreased on textured surfaces compared to smooth surfaces.
• Nanotopography promoted focal complex (FX) formation but resulted in narrower focal adhesions (FAs) confined to interpillar regions.
• Fibroblasts deformed the 400-nm pillars, indicating mechanical interaction with the topography.

Conclusions:

• Surface nanotopography can significantly alter cell adhesion and proliferation dynamics.
• Geometric constraint imposed by surface texture limits focal adhesion maturation, thereby reducing cell proliferation.
• This study proposes geometric constraint as a key mechanism by which surface topography regulates cell behavior in tissue engineering applications.