A comparative study of the physiochemical and biological properties of tetracycline-loaded polypropylene sutures prepared through different plasma treatments

In this work, a comparative investigation was done on the physiochemical and biological properties of tetracycline-loaded polypropylene sutures prepared through nitrogen, oxygen, and/or argon plasma treatment/grafting method. Two types of multi- and monofilament polypropylene sutures were treated by various plasma gases followed by acrylonitrile and acrylic acid grafting. Nitrogen and oxygen plasmas compared to argon plasma showed higher efficiencies in functionalization and wettability of the filaments. Tetracycline hydrochloride loading on the plasma-treated/grafted filaments was done through immersion method. The prepared filaments were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD) and attenuated total reflection–Fourier transform infrared spectroscopy (ATR-FTIR) and their mechanical properties were determined, accordingly. The antibacterial effect of tetracycline hydrochloride was studied over two different Gram-positive and Gram-negative bacteria. No cytotoxicity was observed for these filaments on the L929 fibroblast cell line using MTT assay. The release profile of the tetracycline hydrochloride-loaded sutures reached the stationary phase in 25 h. Nitrogen plasma-treated sutures showed the highest drug release profile among the others. The current work showed the effects of different plasma treatments on the biological, mechanical, and chemical properties of the tetracycline-loaded polypropylene sutures. The nitrogen plasma was superior to oxygen plasma in the opinion of grafting rate, mechanical properties, and antibacterial activities.

Graphical abstract