In cancer therapy, the selective targeting of cancer cells while avoiding side effects to normal cells is still full of challenges. Here, we developed dual-functionalized crescent microgels, which selectively captured and killed lung cancer cells in situ without killing other cells. Crescent microgels with the inner surface of the cavity functionalized with antibody and containing glucose oxidase (GOX) in the gel matrix have been produced in a microfluidic device. These microgels presented high affinity and good selectivity to lung cancer cells and retained them inside the cavities for extended periods of time. Exposing the crescent hydrogels to physiological concentrations of glucose leads to the production of a locally high concentration of H₂O₂ inside the microgels’ cavities, due to the catalytic action by GOX inside the gel matrix, which selectively killed 90 % cancer cells entrapped in the microgel cavities without killing the cells outside. Our strategy to create synergy between different functions by incorporating them in a single microgel presents a novel approach to therapeutic systems, with potentially broad applications in smart materials, bioengineering and biomedical fields.

Chitosan has been used to cross-link poly(acrylic acid) to give three pH-sensitive hydrogels designed to control the release of the drugs amoxicillin and meloxicam. The extent of cross-linking and solution pH was found to dominate the swelling behavior of these hydrogels as shown by scanning electron microscopy and swelling time dependencies. The rates of release of amoxicillin and meloxicam from the loaded hydrogels increased with increase in pH consistent with the extent of hydrogen bonding between hydrogel components and between the hydrogel and the drugs being important determinants of release rate. Both the Korsemeyer-Peppas and Weibull models fitted release data consistent with drug release occurred through a combination of drug diffusion and hydrogel relaxation processes. These hydrogels appear to provide an ideal basis for controlled drug delivery systems.