Imaging injectable liposomal hydrogels using CEST MRI for applications in the brain

Nanocarrier-loaded hydrogel shows good prospects in biomedical application. However, there is lack of noninvasive methods for real time monitoring to guide therapy. Here, we developed a CEST-nanosensor incorporated injectable hydrogel using two most commonly used hydrogel (alginate, and hyaluronan-methylcellulose (HAMC)) and liposomes. Both hydrogels showed storage modulus (G’) comparable to native brain tissue and good injectabilities. Moreover, we observed that our LipoCEST hydrogels generate unique CEST contrasts at 5 ppm (barbituric acid (BA), drug) and -3.4 ppm (liposomes) on 3T, facilitating the multicolor CEST imaging and imaging-guided therapy in brain applications.