Nanodiamond materials can serve as highly versatile platforms for delivery of drugs.In this study,five kinds of salt (NaCl,Na2SO4,Na2C2O4,NaAc,Na3Cit) were chosen to studied the salt effects on loading of doxorubicin hydrochloride (DOX) onto Nanodiamond (ND ~140 nm).The results showed that the salts were able to promote the adsorption of DOX onto the ND (Fig.1).The ranking of capability of promoting the adsorption of DOX was Na3Cit>Na2C2O4>NaAc>NaCl≈Na2SO4.Furthermore,the drug release behavior of the ND-DOX was investigated under a simulated physiological condition (PBS,pH 7.4) and in an acidic environment (PBS buffer,pH 5.3 and 6.6) at 37℃(Fig.2).ND-DOX showed a much faster DOX release at pH 5.3 and 6.6 than at pH 7.4.Therefore,the result means that the much higher release rate observed at pH 6.6 and 5.3 can help to quickly provide a sufficient level of DOX in the tumor tissue/cells,thereby greatly enhancing the efficacy of cancer therapy.