Manipulating the solution environment to control the surface roughness of elastin-based polymer coatings

Area of Science:

• Biomaterials Engineering
• Tissue Engineering
• Surface Science

Background:

• Elastin-like polypeptides (ELP) are biocompatible elastin mimics.
• ELP conjugated with polyethyleneimine (PEI) promote 3D cell aggregate formation.
• Controlling coating properties is crucial for mimicking in vivo cell environments.

Purpose of the Study:

• To control the surface roughness of ELP and ELP-PEI coatings.
• To investigate the effect of polymer concentration and salt on coating deposition.
• To assess coating stability and develop methods for improving it.

Main Methods:

• Coating glass, polystyrene, and tissue-culture polystyrene substrates with ELP and ELP-PEI.
• Varying polymer concentration (0.5-1.5 mg/mL) and salt concentration (0-0.2 M PBS).
• Utilizing Atomic Force Microscopy (AFM) to measure surface roughness (Ra) and assessing stability through repeated cell media changes and sonication after crosslinking with hexamethyl diisocyanate.

Main Results:

• ELP coatings exhibited higher average roughness (Ra) than ELP-PEI coatings.
• Surface roughness increased with repeated cell media changes over 11 days.
• Crosslinking with hexamethyl diisocyanate significantly stabilized surface roughness against media changes and sonication.

Conclusions:

• Parameters for controlling roughness in elastin-based coatings were established.
• Crosslinking enhances the stability of these coatings for long-term cell culture.
• Developed coatings support stable, long-term in vitro cell culture with controlled surface topography.