Development and characterization of functionalized self-assembling nanopeptide on the effect of angiogenesis for injured brain tissue regeneration

Abstract

Event Abstract Back to Event Development and characterization of functionalized self-assembling nanopeptide on the effect of angiogenesis for injured brain tissue regeneration Kai-Chiech Chang1, Yung-Jen Chuang2, Wen-Han Chang3, Ming-Yuan Huang3 and Tzu-Wei Wang1 1 National Tsing Hua University, Department of Materials Science and Engineering, Taiwan 2 National Tsing Hua University, Department of Medical Science & Institute of Bioinformatics and Structural Biology, Taiwan 3 Mackay Memorial Hospital, Department of Emergency, Taiwan Introduction: Tissue and organ regeneration has been regarded as an optimal therapeutic strategy for traumatic brain injury. In this study, we proposed a three-dimensional (3D) hydrogel matrix to facilitate neoangiogenesis around damaged brain wound region[1]-[3]. A functionalized peptide, RADA16-SVVYGLR (AcN-RADARADARADARADASVVYGLR-CONH2), is designed, synthesized, and self-assembles into nanofibers network to form hydrogel with fiber entanglements[4]. The hydrogel with mechanical stiffness provides a suitable substrate for encapsulated neural stem cells adhesion and differentiation. The functional peptide, SVVYGLR, had been shown to regulate growth of hemopoietic stem cells and to induce angiogenesis[5],[6]. From previous in vitro and in vivo study, the hydrogel made of RADA16-SVVYGLR was compatible for cells proliferation in zebrafish embryos development. We expect that functionalized peptide hydrogel would create a favorable microenvironment for neural tissue repair and serve as a potential therapeutic application in traumatic brain damages. Method: Peptide solution: All aqueous peptide solutions were prepared by dissolving in Milli-Q water, stored at 4°C. Physiochemical properties analyses: Peptide secondary structure, nanofibers morphology and hydrogel rheology were analyzed by circular dichroism (CD), transmission electron microscopy (TEM), and rheometer, respectively. In vivo study: Zebrafish line (Tg(kdr:EGFP)) were used to perform zebrafish embryo toxicity test (zFET) including analysis of the survival rate and the development of intersegmental vessels (ISVs). Results and Discussion: The CD spectrum showed RADA16 and RADA16-SVVYGLR were in the form of beta sheet with minimum at 216 nm and maximum at 196 nm (Fig. 1). Morphology of both peptides were nanofibers network, developing scaffolds favorable to cellular processes and molecules transportation (Fig. 2). As the CD and TEM results, the self-assembling mechanism was not changed dramatically after linking the motif on the terminal of RADA16. The rheology of hydrogels showed that G’ was higher than G’’, indicating the gel-like property. (Fig. 3) The survival rate of fish embryos treated with peptide hydrogel was similar to that in the control group (Fig. 4). After 72 hours post-fertilization, the phenotypic traits of ISVs growth were identical in fish treated with hydrogel and that in control group, showing the normal physiological growth of ISVs to the DLAVs and PCVs. (Fig. 5) The zFET showed toxicity was not observed. Conclusion: The self-assembling peptides in our study, characterized as beta sheet secondary structure with angiogenic sequence, formed into a gel-like 3D scaffold with nanofibers network which was a suitable matrix for NSCs proliferation and a biocompatible biomaterial by zebrafish animal model. The hydrogel scaffold by functionalized self-assembling peptide has a potential role in clinical application to improve tissue regeneration. Dr. Wen-Han Chang; Dr. Ming-Yuan Huang; Prof. Yung-Jen Chuang; NTHU-Mackay Memorial Hospital Joint Research Program (103N2770E1); Research funding support of Ministry of Science and Technology, R.O.C. (104-2628-E-007-002-MY3)