Processing-structure-property relationships of biopolyester/zinc oxide fibrous scaffolds engineered by centrifugal spinning

This study addresses the processing of nonwoven fibrous materials obtained by centrifugal spinning method, namely Forcespinning; a high yield and low production cost technique little explored in this field. Poly(D, L-lactic acid) (PDLLA) and poly(3-hydroxybutyrate) (PHB) were used as matrices and reinforced with zinc oxide nanoparticles (n-ZnO). The morphology, mechanical, and thermal performance of the developed composites were analyzed as well as the antibacterial effect of n-ZnO. Fibrous materials with n-ZnO concentrations of 1, 3, and 5 wt. % for PDLLA and 1 and 3 wt. % for PHB were evaluated. The results showed that the incorporation of n-ZnO produces an increase in the viscosity of the precursor solutions for both polymeric systems, which caused an increase in the average fiber diameter, though the morphology was not affected, obtaining mostly long, continuous, and homogenous fibers. In addition, a decrease in thermal stability was observed to a greater extent in PDLLA systems. Regarding the mechanical performance, optimal properties were obtained at a concentration of 3 and 1 wt. % of n-ZnO for PDLLA and PHB, respectively. Antibacterial studies showed that PHB with 1 and 3 wt. % of n-ZnO effectively combat strains ofE. coliandS. aureus, presenting 100% of strain growth inhibition. In the case of PDLLA, a higher n-ZnO concentration (5 wt. %) was required to reach a strain growth inhibition above 97%. Finally, cell viability tests demonstrated that the designed fibrous mats support cell proliferation, indicating their potential for use as scaffolds in bone tissue regeneration.