Enhanced antibacterial activity of PEO-chitosan nanofibers with potential application in burn infection management.

Chitosan (CS) is a well-known biological macromolecule having numerous applications due to its exceptional properties especially in the form of nanofibers. The antibacterial activity is compromised when co-polymers are added to electrospun CS but, the reproducibility can be enhanced which is key to commercialization. We have tried to enhance the antibacterial activity of chitosan based nanofibers with the addition of Zinc oxide (ZO) nanoparticles and ciprofloxacin (model drug) at very low concentrations. The rheology of solutions was studied along with the process parameters for the optimization of nanofibers using response surface methodology. Nanofibers having diameter of 116 nm with a SD of only 21 nm were optimized. ZO loaded nanofibers showed better thermal stability. Different drug release models were fitted to drug release profile. The release was pH dependent best followed by Zero order and Hixson Crowell release models. Good antibacterial activity and non-toxicity was observed against human dermal fibroblast and keratinocytes cell lines (>82.5%) which justifies its potential to eliminate or prevent infection in burn wounds with less side effects due to low amount of drug.

Quantitative approaches of nanofibers organization for biomedical patterned nanofibrous scaffold by image analysis.

This study proposes a novel design of a laboratory built static collector using the 3D printing technology. This new collector produces aligned-to-random nanofibers in nanofibrous scaffold through electrospinning process. A design of experiment (DOE), based on response surface, analyzes the effect of the main process parameters; concentration, voltage, and distance; on the responses diameter and orientation. A quantifying approach has been used to investigate the orientation of nanofibers in the produced patterned scaffold through Fourier transforms method. The obtained results have proven a good potential to be used in tissue engineering application, especially for cells requiring specific guidance. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 106A: 2963-2972, 2018.

Nanobead-on-string composites for tendon tissue engineering.

Tissue engineering holds great potential in the production of functional substitutes to restore, maintain or improve the functionality in defective or lost tissues. So far, a great variety of techniques and approaches for fabrication of scaffolds have been developed and evaluated, allowing researchers to tailor precisely the morphological, chemical and mechanical features of the final constructs. Electrospinning of biocompatible and biodegradable polymers is a popular method for producing homogeneous nanofibrous structures, which might reproduce the nanosized organization of the tendons. Moreover, composite scaffolds obtained by incorporating nanoparticles within electrospun fibers have been lately explored in order to enhance the properties and the functionalities of the pristine polymeric constructs. The present study is focused on the design and fabrication of biocompatible electrospun nanocomposite fibrous scaffolds for tendon regeneration. A mixture of poly(amide 6) and poly(caprolactone) is electrospun to generate constructs with mechanical properties comparable to that of native tendons. To improve the biological activity of the constructs and modify their topography, wettability, stiffness and degradation rate, we incorporated silica particles into the electrospun substrates. The use of nanosize silica particles enables us to form bead-on-fiber topography, allowing the better exposure of ceramic particles to better profit their beneficial characteristics. In vitro biocompatibility studies using L929 fibroblasts demonstrated that the presence of 20 wt% of silica nanoparticles in the engineered scaffolds enhanced cell spreading and proliferation as well as extracellular matrix deposition. The results reveal that the electrospun nanocomposite scaffold represents an interesting candidate for tendon tissue engineering.