Solution blow spun poly(lactic acid)/hydroxypropyl methylcellulose nanofibers with antimicrobial properties

Poly(lactic acid) (PLA) nanofibers containing hydroxypropyl methylcellulose (HPMC) and tetracycline hydrochloride (THC) were solution blow spun from two different solvents, chloroform/acetone (CA, 80:20 v/v) and 2,2,2-triflouroethanol (TFE). The diameter distribution, chemical, thermal, thermal stability, water sorption, and antimicrobial properties were examined for the fibers. Fibers spun from CA generally had larger fiber diameters and wider fiber diameter distributions than those spun from TFE. Fourier transform infrared (FTIR) spectroscopy results indicated successful incorporation of HPMC and THC into the fibers. Also, phase separation occurred between PLA and HPMC in the fibers. Fibers containing higher HPMC concentrations showed greater water sorption values, due to HPMC being more hydrophilic than PLA. In addition, fibers containing HPMC had larger inhibitory zones against Escherichia Coli and Listeria monocytogenes than those without HPMC. This was due to THC having better miscibility with HPMC than PLA and HPMC being able to swell and release more THC when in contact with water. Fibers spun from TFE and CA had comparable inhibitory zones, indicating the solvents did not affect antimicrobial properties. All fibers remained effective against bacteria even after six days.