ALB and neoplasm: Researchers had also constructed pH-sensitive albumin-based hydrogels using BSA, ß-propranolol was rapidly released at pH 1.0 and complete release of ß-propranolol was observed after 1 h at pH 6.8 using ß-propranolol as a model drug, and it can precisely deliver model drugs to tumor cells (El-Sherif et al., 2009).