pH-sensitive biomaterials for cancer therapy and diagnosis

Recently developed pH-sensitive biomaterials responsive to tumor extracellular pH and/or late endosomal and lysosomal compartments serve for anticancer drug delivery and identifying the location of solid tumors. It also helps cytosolic delivery of macromolecular therapeutics as well as protection and sustained release of the same. The advances in pH-sensitive biomaterials and technical applications have been rich for the last a few decades and their in vivo utility has been noticeable. However, no translational activity has been apparent by far, except high feasibility of the visualization of tumor residues during debulking surgery by in situ tumor pH imaging. A variety of factors should be addressed before translation. The most urgent step is to develop appropriate tumor models that can bridge the gap between current rodent tumor models and clinical patients, thus improving the translational predictability. Current rodent models are not avoidable to prove new delivery technology; however, no models yield improved predictability.