Tailoring polycaprolactone/silk electrospun nanofiber yarns by varying compositional and processing parameters

In the last few years, micro/nanofibers of polycaprolactone/silk (PCL/S) blend have been investigated for biomaterial applications due to a valuable combination of biodegradability, biocompatibility, and bioactivity. However, in its most conventional conformation (i.e., mats), its use is limited by poor mechanical properties. One alternative to overcome such issue is the fabrication of nanofiber yarns (NF-Ys) which combines the inherent advantages of nanofibers with superior mechanical properties. Therefore, in this paper, we investigated the production of PCL/S NF-Y by electrospinning using a one step method, focusing on the effect of compositional and processing parameters, such as silk content (0-70%), flow rate, and rotatory collector speed on nanofibers morphology, tensile properties, and processability. SEM analyses and tensile tests showed that by adjusting such parameters, it is possible to change morphology and strength of the yarns. For instance, by decreasing rotary collector speed in the production of PCL/S 70:30 NF-Y, strength increased from 7.01 +/- 1.10 to 12.71 +/- 1.33 MPa. In this context, NF-Ys can be designed to fulfill specific demands by varying electrospinning and compositional parameters, making it possible to produce different structures with tailorable properties, for many applications, including biotextiles.

Automated summary

In recent years, the use of polycaprolactone/silk (PCL/S) blend micro/nanofibers for biomaterial applications has been explored due to their beneficial combination of biodegradability, biocompatibility, and bioactivity. However, the conventional form of these fibers (mats) has limited use due to poor mechanical properties. To overcome this issue, nanofiber yarns (NF-Ys) have been fabricated, combining the advantages of nanofibers with superior mechanical properties. This paper investigates the production of PCL/S NF-Ys by electrospinning and explores the effect of composition and processing parameters on the morphology, tensile properties, and processability of these nanofibers.