Emerging Patents for Cancer-Targeted Nanomedicines

Abstract

1Department of Pharmacology, Institute of Medical Sciences, Banaras Hindu University, Varanasi, 221005, India 2Department of Pharmaceutics, PSG College of Pharmacy, Peelamedu, Coimbatore, 641004, India *Author for correspondence: Tel.: +91 923 519 5928 Fax: +91 542 236 7568 E-mail: muthubits@rediffmail.com Nanomedicines are now being used in various cancer therapies that employ targeted ligands. Targeted nanomedicines have become a corner stone of a paradigm shift in the safe delivery of therapeutic agents, with the added benefits of controlled drug release, improved compliance and the avoidance of adverse effects. Advanced nanomedicines are now being used to target specific organelles within individualized cells [1]. Theranostic/multifunctional nanomedicines can be used to target drugs to cancerous site, while at the same time loading the diagnostic and therapeutic agent [2,3]. Government agencies such as the US FDA and the USPTO define nanoparticles as being less than 100 nm in size [4]. Nevertheless, a size limitation of less than 100 nm is not critical from a nanoformulation or efficacy point-of-view, since the desired or ideal qualities (e.g., increased bioavailability, reduced toxicity, reduction in dose, fewer adverse effects and enhanced solubility) are also achieved in size ranges greater than 100 nm. Therefore, nanoparticles for pharmaceutical use are thus defined: “Nanoparticles in the nanomedicines are colloidal particles ranging in size from 10 to 1000 nm (1 μm) in which the active principle (drug and/or diagnostic agent) is loaded’’ [1]. The various types of nanomedicines include, for example, polymer-based nanoparticles, liposomes, solid lipid nanoparticles, dendrimers, polymeric micelles and carbon nanotubes [5,6]. The surfaces of nanomedicines for targeted drug delivery are fabricated via the attachment of various targeting ligands (e.g., receptor-specific antibodies and antigens) to promote the delivery to cancer sites. Recently, a significant number of patents have been released for nanomedicines [4]. This editorial, will focus specifically on patents for cancer site-targeted nanomedicines.