Chemotherapy is one of the most effective methods of treating
tumors in clinical study currently, but
drug side effects usually are unbearable to the patient, which also makes it difficult to continue
chemotherapy. Enhanced drug efficacy and reduced
drug side effects are the main strategies for
tumor therapy. Herein, based on biochemical regulation,
theanine liposomes were designed to adjuvant
doxorubicin (DOX)
therapy, which can reduce the adverse reactions and enhance the effect of DOX.
Stigmasterol was applied instead of traditional
cholesterol for reducing the risk of
cardiovascular disease. The as-prepared
theanine liposomes by two methods had optimal sizes (154.8 and 169.0 nm), which can effectively accumulate in
tumor tissues. In vitro experiments demonstrated that the
theanine liposomes had a good effect of sustaining drug release. Cell uptake indicated that the presence of
theanine can effectively inhibit
glutathione (GSH) levels in cells and increase the uptake of DOX. In
tumor bearing mice experiments, the combination of the
theanine liposomes and DOX showed a better
tumor inhibitory effect with a smaller
tumor volume (2.7 fold) compared with that of the free DOX group. Meanwhile, under the mediation of
theanine, the amount of
doxorubicin was greatly reduced to achieve the same
therapeutic effect, and the side effects of the drug were largely inhibited. Therefore,
theanine liposomes have great application potential in
tumor chemotherapy.