oa Editorial: [Hot topic: The Metabolism of Nanotechnology-Based Drugs (Guest Editors: Ming-Fa Hsieh and Chun-Ming Huang)]

Nanotechnology-based drugs, newly emerging pharmaceutics, are characterized by the physical sizes of the drugs engineering by various nano-materials such as nanoparticles [1, 2]. These nano-sized drugs can be designed to target specific tissues and organs by chemically and/or biologically tailoring the surfaces of particles or biomaterials [3, 4]. This issue covers four papers reviewing the strategy of nano-sized anti-cancer drugs to overcome the clinical unmet needs. C. J. Hu and L. Zhang summarize the mechanism of chemoresistance acquired by patients during chemotherapy. Furthermore, the smart biomaterials designed to overcome the drug resistance and to alleviate adverse side effects in patients. The majority of these biomaterials are the biomedical polymers that are commonly used as the excipients to formulate the potent anti-cancer drugs. N. Cuong and M. F. Hsieh describe preclinical and clinical improvements in the therapeutic efficacy of cancers using polyethylene glycol and polyamidoamine as low-toxic polymeric excipients. Likewise, W.T. Li reminds us that nanotechnology-based approach can also be applied to enhance the efficacy of photodynamic therapy of cancers. A comprehensive table of clinically-available photo sensitizers is provided in this review article for reader’s reference. In an article by Gigi N. C. Chiu and her colleagues, novel anti-cancer cocktails with rationally designed multi-targeting functions are displayed. The literatures reviewed cover a full range of agents including cytotoxic drugs, chemosensitizers, inhibitors of Pglycoprotien (multidrug resistance protein) and molecular targeted agents. Aside from cancer therapy, C. M. Huang and co-works give readers a specific insight into the biochemistry of the methicillin-resistant bacterial infection in which nanotechnology-based strategy is emerging to combat. The research advances of the drug and/or gene targeting relies heavily on the trafficking of agents in the sub-cellular level. Y. Y. Huang and his colleagues introduce the polymeric materials selected as gene carrier. Because of the charged nature of genes, the materials posses charges in order to encapsulate with genes. Therefore, the toxicity and metabolism are addressed in this article. This issue not only encompasses polymeric excipients to effectively fabricate pharmaceutics into nanoparticles, the reviews in the engineered inorganic nanoparticles and Chinese Herbs are covered to broaden the scientific scope of the current issue. R. A. Sperling and coworkers highlight the impact of inorganic nanoparticles on immune system, in particular the surface properties. S. Huang and W. H. Chang report the formulation of Chinese Herb with improved the therapeutic efficacy. We hope you enjoy reading the articles in this issue. Thanks to the reviewers of this issues for improving the quality of the articles.