Fabrication of superabsorbent ultrathin nanofibers using mesoporous materials for antimicrobial drug-delivery applications

The goal of this study was to prepare functionalized, ultrathin nanofibers using mesoporous materials (TS-1 zeolite) with maximum capability to both absorb drug and control drug release (these fibers are herein referred to as PZ-01); a second goal was to prepare nanofibers that exhibit biodegradability after drug release. Under optimal conditions, the characteristic of TS-1 zeolite enabled the preparation of ultrathin nanofibers with diameters below 100 nm, or one-twentieth the size of homo-poly(butylene succinate) (PBS) fibers. In addition, PZ-01 nanofibers exhibited high drug loading capacity compared to homo-PBS fibers. This result was attributable to the large surface area of ultrathin nanofibers and to the strong ionic interaction between hydrophilic drugs and the metal ions of TS-1 zeolite. In vitro cytostatic assay indicated that prepared PZ-01 has cytostatic action toward both Gram-positive and Gram-negative bacteria. The excellent drug wetting behavior of PZ-01 led to longer drug-release times. After drugrelease tests, antibacterial tests confirmed that homo-PBS fibers had diminished antibiotic activity regardless of the type of bacteria, whereas the antibacterial activity of tested PZ-01 was highly efficient against both Gram-positive and Gram-negative bacteria. In the cell viability test, PZ-01 exhibited a greater decrease in cytotoxicity and an increase in cell viability compared with the homo-PBS nanofiber. Based on this research, we anticipate that these materials will be promising candidates for biomedical applications such as biofilters for microbes, wound dressings, and drug-delivery products.