Electrospun multi-functional medicated tri-section Janus nanofibers for an improved anti-adhesion tendon repair

The occurrence of limb disability resulting from tendon injuries is not uncommon due to the limited treatment options available. Among these methods, physical barriers are often used during and after operation. In this study, we developed a new type of nanofibrous barrier using a tri-fluid side-by-side electrospinning process. The nanofibers consisted of three sections arranged in an eccentric Janus manner, each loaded separately with three functional ingredients beeswax (BW), quercetin and ketoprofen. Hydrophobic polylactic acid and polycaprolactone were utilized as the polymeric matrices, and the outer crescent section's beeswax content was adjusted to enhance the barriers' hydrophobicity. Scanning electron microscopy and transmission electron microscopy revealed the linear morphology and tri-section Janus stricture of the nanofibers. X-ray diffractometry and Fourier transform infrared spectroscopy confirmed the amorphous state of the drugs and the compatibility between the drugs and polymers. Tensile experiments showed that the nanofibers have the desired mechanical properties to support tendon growth. In vitro drug release experiments demonstrated that the nanofibers could effectively extend the drug release time periods enabling a continuous drug treatment during the slow tendon repair process. Both in vitro and in vivo anti-adhesion tests verified the effective applications of the nanofibrous barriers. The anti-adhesion nanofibrous barriers prepared by tri-fluid side-by-side electrospinning in this study are potential candidates in the clinic application of tendon repair. The methodologies presented here can be explored to develop a range of novel functional nanomaterials with three side-by-side sections to load with three different active ingredients, where each section contributes a distinct function for a synergistic therapy.