2. Academic Validation
  3. Assembly Pathway Selection of Designer Self-Assembling Peptide and Fabrication of Hierarchical Scaffolds for Neural Regeneration

Assembly Pathway Selection of Designer Self-Assembling Peptide and Fabrication of Hierarchical Scaffolds for Neural Regeneration

  • ACS Appl Mater Interfaces. 2018 Aug 8;10(31):26128-26141. doi: 10.1021/acsami.8b10764.
Yuyuan Zhao,  Rong Zhu,  Xiyong Song 1,  Zheng Ma 2,  Shengfeng Chen,  Dongni Wu,  Fufeng Liu 2,  Songying Ouyang 1,  Jianguo Zhang 3,  Seeram Ramakrishna 4,  Xiaofeng Zhu 5,  Liumin He
Affiliations

Affiliations

  • 1 National Laboratory of Biomacromolecules, Institute of Biophysics , Chinese Academy of Sciences , Beijing 100101 , China.
  • 2 Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education, College of Biotechnology , Tianjin University of Science & Technology , Tianjin 300457 , P. R. China.
  • 3 Center for Biological Imaging, Institute of Biophysics , Chinese Academy of Sciences , Beijing 100101 , China.
  • 4 Department of Mechanical Engineering, Faculty of Engineering , National University of Singapore , Singapore 117576 , Singapore.
  • 5 Department of Chinese Medicine, The First Affiliated Hospital of Jinan University , Jinan University , Guangzhou 510632 , China.
PMID: 30001104 DOI: 10.1021/acsami.8b10764
Abstract

The self-assembling peptide (SAP) RADA 16-I has been modified with various functional motifs to improve its performances in biomedical applications. Nevertheless, the assembly mechanisms of designer functional RADA 16-I SAPs (F-SAPs) have not been clearly illustrated. The main problem is the difficulty in preparing a completely molecular aqueous solution of F-SAP. In the current study, we demonstrated that different procedures for preparing the F-SAP solution could result in the formation of different conformations and consequently micro/macroscopic morphologies. F-SAP was molecularly dissolved in an appropriate solvent, such as hexafluoroisopropanol (HFIP), as evidenced by random coil conformation characterized by circular dichroism spectroscopy and morphologies under transmission electron microscopy. The monomers were induced into monolayers when the F-SAP solution in HFIP was adsorbed on mica as observed by atomic force microscopy. However, nanoscaled filaments containing β-sheets dominated in the F-SAP aqueous solution, in which case water acted as a poor solvent of F-SAP. Furthermore, the results of molecular dynamics simulation implicated that water facilitated F-SAP aggregation, whereas HFIP inhibited it. The β-sheet assemblies formed in water exhibited a high kinetic stability and did not disassemble rapidly after the addition of HFIP. Our study indicated that selecting the right assembly pathway of F-SAP required for targeted functions, for example, delivery of hydrophobic drugs in aqueous conditions, could be achieved by optimizing the preparation protocol in addition to molecular design. Moreover, hierarchical scaffolds mimicking the natural extracellular matrix could be fabricated by the direct electrospinning of F-SAP molecular solution in HFIP and biodegradable polymer for applications in neural regeneration by promoting neural differentiation, neurite outgrowth, and synapse formation.

Keywords

assembly pathway; functional self-assembling peptides; nanofiber hydrogel; neural regeneration.

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