Sequence effects of self-assembling multidomain peptide hydrogels on encapsulated SHED cells

Area of Science:

• Biomaterials Science
• Stem Cell Biology
• Nanotechnology

Background:

• Multidomain peptides (MDPs) are versatile self-assembling biomaterials.
• Modifying peptide sequences can alter nanofiber morphology and cellular response.
• Stem cells from Human Exfoliated Deciduous teeth (SHED) are promising for regenerative medicine.

Purpose of the Study:

• To synthesize and characterize novel threonine-based MDPs.
• To investigate the impact of threonine modification on nanofiber morphology.
• To evaluate the effect of new MDPs on SHED cell attachment, morphology, and expansion.

Main Methods:

• Synthesis of three new threonine-modified MDP sequences.
• Characterization of self-assembled nanofibers using Circular Dichroism (CD), Infrared (IR) spectroscopy, Atomic Force Microscopy (AFM), and Transmission Electron Microscopy (TEM).
• Assessment of SHED cell behavior (attachment, morphology, proliferation) within peptide hydrogels via Scanning Electron Microscopy (SEM) and cell counting.

Main Results:

• New threonine-based MDPs self-assemble into curved antiparallel β-sheet nanofibers forming porous hydrogels.
• SHED cells exhibited faster attachment and spreading on serine-based hydrogels compared to threonine-based ones.
• Serine-based hydrogels promoted SHED cell expansion, while threonine-based hydrogels showed limited expansion and altered cell morphology (stellate or rounded).

Conclusions:

• MDP sequence modifications, specifically serine to threonine, significantly influence nanofiber structure and SHED cell behavior.
• Threonine-based hydrogels require the RGDS sequence for effective SHED cell attachment, unlike serine-based counterparts.
• The study highlights the potential of tailored MDPs for controlling stem cell fate and function in regenerative applications.