Micro- and nano-patterned elastin-like polypeptide hydrogels for stem cell culture

Area of Science:

• Biomaterials Science
• Tissue Engineering
• Cellular Mechanobiology

Background:

• Developing soft biomaterials with tunable topography is crucial for mimicking native tissue environments.
• Recombinant-engineered proteins like elastin-like proteins (ELP) offer bio-responsiveness but require precise topographical control.
• Understanding cell responses to micro- and nano-scale topographical features is key for regenerative medicine.

Purpose of the Study:

• To imprint submicron-sized topographical patterns onto soft elastin-like protein (ELP) hydrogels.
• To investigate the influence of these tunable ELP topographies on adipose-derived stem cell (ADSC) behavior.
• To establish a method for creating tissue-mimicking architectures for cell response studies.

Main Methods:

• Micro-molding of ELP hydrogels using polydimethylsiloxane (PDMS) molds with varying periodicities (0.24-4.54 μm).
• Characterization of imprinted patterns using coherent anti-Stokes Raman scattering (CARS) and atomic force microscopy (AFM).
• Assessment of ADSC orientation and response to different ELP topographical features under hydrated conditions.

Main Results:

• Submicron wavy patterns were successfully imprinted into ELP hydrogels down to 0.37 μm periodicity.
• ELP ridge dimensions (width/height) were dependent on hydration levels, ranging from 79% to 150% of mold width.
• ADSCs showed significant orientation along aligned ELP patterns with periodicities ≥0.60 μm and specific heights, while random orientation occurred on smaller features or flat surfaces.

Conclusions:

• Micro-molding of ELP is an effective technique for creating tunable, hierarchical, tissue-mimicking architectures.
• The imprinted ELP topographies, including nano-sized protein aggregates, influence ADSC orientation.
• This approach enables orthogonal screening of cell responses to topography and ligands at physiologically relevant elastic moduli.