Temperature-sensitive semi-IPN composite hydrogels for antibacterial applications

This investigation aims to develop bacterial-resistant temperature-sensitive semi-IPN silver composite hydrogels via a three-step method. Primarily, the temperature-sensitive semi-IPN hydrogels of N-isopropylacrylamide and various concentrations of Pluronic F-127 (PF 127), have been prepared via a free radical polymerization technique. Furthermore, silver ions were encapsulated in the temperature-sensitive semi-IPN hydrogels via the swelling process. Finally, the bacterial-resistant semi-IPN silver composite hydrogels were developed by using an aqueous neem extract as a reducing agent. Semi-IPN hydrogels with higher amount of PF-127 showed a water uptake that was three times better than the pristine poly (N-isopropylacrylamide). The phase transition temperature of the semi-IPN silver composite hydrogels was found to be 34.24 degrees C, which was confirmed from the swelling and the DSC studies. The resulting hydrogels were characterized by: FTIR, UV-vis, X-ray diffraction, SEM and TEM analyses. The TEM results confirmed the fact that the nanoparticles formed were of spherical shape with a dimension of (similar to)8 +/- 2 nm. The semi-IPN silver-composite hydrogels showed excellent bacteria inhibition against gram-positive bacteria. The results demonstrated that the temperature-sensitive semi-IPN silver-composite hydrogels developed can be employed for clinical applications.