Synthesis and Characterization of Novel Self-Assembling Tetrapeptides for Biomedical Applications and Tissue Engineering

  • Hepi Hari Susapto

Student thesis: Doctoral Thesis

Abstract

Molecular self-assembly is the process of molecules able to associate into more ordered structures. Examples of self-assembling molecules is a class of ultrashort amphiphilic peptides with a distinct sequence motif, which consist of only three to seven amino acids. These peptides can self-assemble to form nanofibrous scaffolds, such as in form of hydrogels, organogels or aerogels, due to their amphiphilic structure which contains a dominant hydrophobic tail and a polar head group. Interestingly, these peptide scaffolds offer a remarkably similar fiber topography to that one found in collagen which is a dominant part of the extracellular matrix. The resemblance to collagen fibers brings a potential benefit in using these peptide scaffolds together with native human cells. Specifically, they can maintain high water content over 99 % weight per volume and are suitable for tissue engineering and regenerative medicine applications. Over the last decade, they have shown promising therapeutic potential in treating several diseases thanks to their high activity, target specificity, low toxicity, and minimal nonspecific and drug-drug interactions. This dissertation describes how to characterize and use ultrashort amphiphilic peptides for tissue engineering and biomedicine. The first chapter offers an overview of already reported self-assembling ultrashort peptides and their applications. As a proof-of-concept, ultrashort peptide scaffolds were used for osteogenic differentiation. Peptide nanoparticles were embedded into 5 peptide hydrogels with the goal to tune the stiffness of the peptide gels. Furthermore, the peptide scaffold was used for the generation of gold and silver nanoparticles after UV irradiation, which allowed the production of nanoparticles in the absence of any additional reducing agent. The mechanism of the generation of these nanoparticles was then investigated. The last chapter describes how tetrameric peptide solutions were utilized for 3D bioprinting applications. Compared to earlier reported self-assembling ultrashort peptide compounds, these tetrapeptides can form hydrogels at an extremely low concentration of 0.1% w/v in a relatively short time under physiological conditions. These promising findings suggest that the peptide solutions are promising bioinks for use in 3D bioprinting.
Date of AwardJun 2021
Original languageEnglish (US)
Awarding Institution
  • Biological, Environmental Science and Engineering
SupervisorCharlotte Hauser (Supervisor)

Keywords

  • Self-assembling peptide
  • Ultrashort Peptide
  • Bioprinting
  • Microfluidic
  • Biomineralization

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