Distinct Roles of Surface Nanostructure and Polymer Degradation in Fibroblast Response to Device Design

Area of Science:

• Biomaterials Science
• Cell Biology
• Tissue Engineering

Background:

• Fibrotic encapsulation is a major cause of biomedical device failure.
• Fibroblasts, not just the immune system, are key regulators of the foreign body response.
• Understanding fibroblast activation is crucial for improving device longevity.

Purpose of the Study:

• To investigate how porous device design influences fibroblast activation into myofibroblasts.
• To evaluate the impact of nanoparticles and polymer matrix on myofibroblast markers.
• To elucidate the role of degradation products in cellular response.

Main Methods:

• Primary human dermal fibroblasts were cultured with devices for four weeks.
• Two factors were varied: tantalum oxide (TaOx) nanoparticle concentration and polymer matrix (PLGA vs. PCL).
• Myofibroblast activation was assessed by measuring markers like alpha smooth muscle actin (αSMA).

Main Results:

• Tantalum oxide nanoparticles had minimal effect, slightly down-regulating αSMA expression.
• The fast-degrading polymer PLGA significantly upregulated multiple myofibroblast markers compared to non-degrading PCL.
• Lactic acid release from PLGA degradation was identified as a key factor affecting cellular metabolism.

Conclusions:

• Device design, particularly the polymer matrix and its degradation rate, significantly influences fibroblast activation.
• Fast-degrading polymers can promote fibrotic responses due to degradation products like lactic acid.
• Optimizing device design, considering material degradation, is essential to mitigate fibrosis and enhance biomedical device success.