Gharaie, Sadaf SamimiMohammad Hossein Dabiri, SeyedAkbari, Mohsen2019-01-242019-01-2420182018Gharaie, S.S., Dabiri, S.M.H. & Akbari, M. (2018). Smart Shear-Thinning Hydrogels as Injectable Drug Delivery Systems. Polymers, 10(12), 1317. https://doi.org/10.3390/polym10121317https://doi.org/10.3390/polym10121317http://hdl.handle.net/1828/10549In this study, we fabricated and characterized a smart shear-thinning hydrogel composed of gelatin and laponite for localized drug delivery. We added chitosan (Chi) and poly N-isopropylacrylamide-co-Acrylic acid (PNIPAM) particles to the shear-thinning gel to render it pH-responsive. The effects of total solid weight and the percentage of laponite in a solid mass on the rheological behavior and mechanical properties were investigated to obtain the optimum formulation. The nanocomposite gel and particles were characterized using Fourier-transform infrared spectroscopy (FTIR), scanning electron microscope (SEM), zeta potential, and dynamic light scattering techniques. Finally, release related experiment including degradability, swelling and Rhodamine B (Rd) release at various pH were performed. The results suggest that incorporation of silicate nanoplatelets in the gelatin led to the formation of the tunable porous composite, with a microstructure that was affected by introducing particles. Besides, the optimum formulation possessed shear-thinning properties with modified rheological and mechanical properties which preserved its mechanical properties while incubated in physiological conditions. The release related experiments showed that the shear-thinning materials offer pH-sensitive behavior so that the highest swelling ratio, degradation rate, and Rd release were obtained at pH 9.18. Therefore, this nanocomposite gel can be potentially used to develop pH-sensitive systems.enshear-thinninghydrogelspH-responsivegelatinlaponitechitosanN-isopropylacrylamidenanocompositeLaboratory for Innovations in Micro Engineering (LiME)Centre for Advanced Materials and Related Technology (CAMTEC)Centre for Biomedical ResearchArticleDepartment of Mechanical Engineering