Background: Various drug delivery systems of antitumor drugs have been developed for past several decades. Nanomedicines, being one of promising choices, have been attracting much attention for the purpose of improving clinical use; because, they sometimes exhibit superior potentiality of enhanced efficacy and reduction of toxicity. Recently, many nanomedicines have been found to have useful results in the preclinical studies, and reached clinical trials or clinically-available stages. As there are few overviews for such situation, the brief explanation of such promising nanomedicines has been performed in this review.
Methods: we focused on several types of antitumor drugs, therapeutic features of which were improved extensively by nano-technological approaches. As to each antitumor drug, physicochemical and antitumor characteristics and improved points in nanomedicines were briefly introduced by referring to main papers and patents.
Results: Promising nanomedicines have been recently developed for doxorubicin, epirubicin, paclitaxel, cisplatin, oxaliplatin and SN-38, and they are now being in clinical trials or clinically used. The pharmacokinetic features are drastically improved in nanomedicines as compared with original drugs, leading to enhanced efficacy and reduced toxicity. The major reason is by passive drug targeting based on enhanced permeability and retention (EPR) effect. At this late date, as antibody/drug conjugate micelles were found to show superior antitumor efficacy, active drug targeting nanomedicines are expected as novel nanomedicines toward clinical use.
Conclusion: This review made clear recent situations of promising nanomedicines of antitumor drugs. The concept of nanomedicines has been demonstrated to be a useful strategy because several of them have reached clinical stage. Nanomedicines with potential of passive targeting or active targeting are expected as superior cancer chemotherapy.