An investigation into the nano-/micro-architecture of electrospun poly ({\epsilon}-caprolactone) and self-assembling peptide fibers

TL;DR

This study explores the integration of self-assembling peptides into electrospun poly({psilon}-caprolactone) fibers to enhance mechanical stability and control nanostructure for biomedical applications.

Contribution

It demonstrates a method to incorporate P11-8 peptides into electrospun PCL fibers, creating a biphasic scaffold with controllable nanostructure and confirmed peptide self-assembly.

Findings

Peptide self-assembly into ta-sheet tapes occurs during fiber formation.

Microstructure can be tuned by adjusting peptide concentration.

The scaffold exhibits a biphasic fiber structure with controlled nanostructure.

Abstract

Self-assembling peptides (SAPs) have the ability to spontaneously assemble into ordered nanostructures enabling the manufacture of "designer" nanomaterials. The reversible molecular association of SAPs has been shown to offer great promise in therapeutics via for example, the design of biomimetic assemblies for hard tissue regeneration. This could be further exploited for novel nano/micro diagnostic tools. However, self-assembled peptide gels are often associated with inherent weak and transient mechanical properties. Their incorporation into polymeric matrices has been considered as a potential strategy to enhance their mechanical stability. This study focuses on the incorporation of an 11-residue peptide, P11-8 (peptide sequence: CH3CO-Gln-Gln-Arg-Phe-Orn-Trp-Orn-Phe-Glu-Gln-Gln-NH2) within a fibrous scaffold of poly ({\epsilon}-caprolactone) (PCL). In this study an electrospinning technique was used to fabricate a biomimetic porous scaffold out of a solution of P11-8 and PCL which resulted in a biphasic structure composed of submicron fibers (diameter of 100-700 nm) and nanofibers (diameter of 10-100 nm). The internal morphology of the fabric and its micro-structure can be easily controlled by changing the peptide concentration. The secondary conformation of P11-8 was investigated in the as-spun fibers by ATR-FTIR spectroscopy and it is shown that peptide self-assembly into \{b}eta-sheet tapes has taken place during fiber formation and the deposition of the fibrous web.