A drug-loaded microbead composition comprising: microbeads comprising a water-swellable polymer material; and a complex comprising a carrier and a therapeutic agent chemically bonded to the carrier, wherein: the complex is embedded within the polymer material; the drug-loaded microbead composition has a water content of less than 1% by weight, based on the total weight of the drug-loaded microbead composition; the water-swellable polymer material is a biodegradable polymer material chosen from poly(4-hydroxybutyrate), methacrylated hyaluronic acids, chitosan-alginate, poly( N- isopropylacrylamide) copolymers, poly( N- isopropylacrylamide)-alginates, poly( N- isopropylacrylamide)-peptides, poly( N- isopropylacrylamide)-α-acryloyloxy-β,β-dimethyl-γ-butyrolactone-hydrophilic Jeffamine, poly( N- isopropylacrylamide)-poly(ethylene glycol) diacrylate-pentaerythritol tetrakis(3-mercaptopropionate), derivatives of any of the foregoing, or combinations of any of the foregoing; and the therapeutic agent is a chemotherapeutic agent having at least some efficacy for treating cancer, particularly hepatocellular carcinoma, liver cancer, prostate cancer, or breast cancer. microbeads comprising a water-swellable polymer material; and a complex comprising a carrier and a therapeutic agent chemically bonded to the carrier, wherein: the complex is embedded within the polymer material; the drug-loaded microbead composition has a water content of less than 1% by weight, based on the total weight of the drug-loaded microbead composition; the water-swellable polymer material is a biodegradable polymer material chosen from poly(4-hydroxybutyrate), methacrylated hyaluronic acids, chitosan-alginate, poly( N- isopropylacrylamide) copolymers, poly( N- isopropylacrylamide)-alginates, poly( N- isopropylacrylamide)-peptides, poly( N- isopropylacrylamide)-α-acryloyloxy-β,β-dimethyl-γ-butyrolactone-hydrophilic Jeffamine, poly( N- isopropylacrylamide)-poly(ethylene glycol) diacrylate-pentaerythritol tetrakis(3-mercaptopropionate), derivatives of any of the foregoing, or combinations of any of the foregoing; and the therapeutic agent is a chemotherapeutic agent having at least some efficacy for treating cancer, particularly hepatocellular carcinoma, liver cancer, prostate cancer, or breast cancer. the complex is embedded within the polymer material; the drug-loaded microbead composition has a water content of less than 1% by weight, based on the total weight of the drug-loaded microbead composition; the water-swellable polymer material is a biodegradable polymer material chosen from poly(4-hydroxybutyrate), methacrylated hyaluronic acids, chitosan-alginate, poly( N- isopropylacrylamide) copolymers, poly( N- isopropylacrylamide)-alginates, poly( N- isopropylacrylamide)-peptides, poly( N- isopropylacrylamide)-α-acryloyloxy-β,β-dimethyl-γ-butyrolactone-hydrophilic Jeffamine, poly( N- isopropylacrylamide)-poly(ethylene glycol) diacrylate-pentaerythritol tetrakis(3-mercaptopropionate), derivatives of any of the foregoing, or combinations of any of the foregoing; and the therapeutic agent is a chemotherapeutic agent having at least some efficacy for treating cancer, particularly hepatocellular carcinoma, liver cancer, prostate cancer, or breast cancer.