ABSTRACT
Three-dimensional cell culture is a novel type of in vitro culture method.This system can mimic the microenvironment of cell growth in vivo,where cells exhibit similar state and function to that in the in vivo environment.Currently,three-dimensional culture system has been widely applied in tissue engineering and tumor cell biology fields,etc.Radiotherapy is an important treatment of cancer.Radioresistance of tumor cells is the main cause of treatment failure,tumor recurrence and metastasis.Tumor cells can exhibit the resistant characteristics in the three-dimensional culture system,similar to those of tumor cells in vivo.Therefore,three-dimensional culture system can be adopted to investigate the radioresistance and underlying mechanism of tumor cells and identify the key factors regulating the radioresistance of tumor cells,which plays a pivotal role in enhancing the radioresistance and improving the effect of radiotherapy.This article will review recent research progress in the radioresistance and sensitization of tumor cells under three-dimensional culture system,aiming to provide reference for relevant investigations.
ABSTRACT
OBJECTIVE:To prepare buspiron hydrochloride sustained-release tablets and to study its release characterization in vitro and the factors affecting drug release.METHODS:Buspiron hydrochloride sustained-release tablets were prepared with hydroxypropyl methylcellulose(HPMC)as hydrophilic gel-matrix material and ethylcellulose(EC)as retarder by wet granulation.The impacts of releasing transmitters,contents of HPMC and EC,and viscosity on the drug release in vitro of the tablets were studied.RESULTS:For the prepared sustained release tablets,the 24h drug release amount was over 90%,and the drug release curve conformed to Higuchi equation.The more contents of HPMC and EC and the higher viscosity of HPMC in the tablets,the slower drug release velocity was obtained;but the viscosity of EC and the releasing transmitters had no significant impacts on the drug release velocity.CONCLUSION:With HPMC and EC as matrix materials,the 24h continuous drug release is available for buspirone hydrochloride sustained-tablets.