Determining the mechanical properties of electrospun poly-ε-caprolactone (PCL) nanofibers using AFM and a novel fiber anchoring technique.
Mater Sci Eng C Mater Biol Appl
; 59: 203-212, 2016 Feb.
Article
in En
| MEDLINE
| ID: mdl-26652365
ABSTRACT
Due to its low cost, biocompatibility and slow bioresorption, poly-ε-caprolactone (PCL) continues to be a suitable material for select biomedical engineering applications. We used a combined atomic force microscopy (AFM)/optical microscopy technique to determine key mechanical properties of individual electrospun PCL nanofibers with diameters between 440-1040nm. Compared to protein nanofibers, PCL nanofibers showed much lower adhesion, as they slipped on the substrate when mechanically manipulated. We, therefore, first developed a novel technique to anchor individual PCL nanofibers to micrometer-sized ridges on a substrate, and then mechanically tested anchored nanofibers. When held at constant strain, tensile stress relaxed with fast and slow relaxation times of 1.0±0.3s and 8.8±3.1s, respectively. The total tensile modulus was 62±26MPa, the elastic (non-relaxing) component of the tensile modulus was 53±36MPa. Individual PCL fibers could be stretched elastically (without permanent deformation) to strains of 19-23%. PCL nanofibers are rather extensible; they could be stretched to a strain of at least 98%, and a tensile strength of at least 12MPa, before they slipped off the AFM tip. PCL nanofibers that had aged for over a month at ambient conditions became stiffer and less elastic. Our technique provides accurate nanofiber mechanical data, which are needed to guide construction of scaffolds for cells and other biomedical devices.
Key words
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Polyesters
/
Nanofibers
Language:
En
Journal:
Mater Sci Eng C Mater Biol Appl
Year:
2016
Document type:
Article
Affiliation country: