Maojo et al systems for medical diagnosis and planning; and laboratory, radiology, and hospital information systems.1 In compu- tational biology, databases of macromolecular sequences, structures, and functions were developed and validated with experimental data.3 Later, the Human Genome Project (HGP) produced massive bioinformatics datasets, and the systems and software tools developed in the project were essential to the completion of the project ahead of schedule.4,5 Over the past decade, biomedical informatics (BMI) has continued to develop as a discipline encompassing both medical informatics and bioinformatics,6–8 based on a large number of research projects. These include over 1000 public databases containing –omics and disease information that are essential to biomedical translational research.9–14 The construction of ontologies such as Gene Ontology5 and many others15–18 provided well-defined terminologies and semantic content for data, information, and knowledge sharing among heterogeneous systems. Despite the broad scope of application of BMI, ranging from molecular medicine to public health, the field of nanomedicine19–21 has received scant attention. However, at the time of writing, almost 3000 references were retrieved in the PubMed database using the search term “nanomedicine.” This number increases daily. Nanotechnology and nanoinformatics The many different challenges of nanotechnology for nano- medicine22,23 suggest the need for a new informatics area. In this biomedical context, nanoinformatics refers to “the use of informatics techniques for analyzing and processing information about the structure and physico-chemical characteristics of nanoparticles and nanomaterials, their interaction with their environments, and their applications for nanomedicine.”24 The term was officially recognized after an initial workshop that took place in Arlington, VA, in 2007.25 This coincided with parallel activities launched at the same time in Europe with support from the European Commission.26 Nanoparticles roughly span the dimensions between 1 and 100 nm. Below 1 nm, their behavior can be explained by known atomic, molecular, and ionic interactions and forces; above roughly 100 nm their properties become similar to the bulk properties of the material.27–29 Inside that range, a particle can exhibit new and variable properties due to quantum effects. In addition, particles , 100 nm may also exhibit enhanced bioavailability and transport in and through biological organisms, tissues, cells, organelles, membranes, and interstices.30–32 Historically, particles within this range 3868 submit your manuscript | www.dovepress.com Dovepress Dovepress have been defined as “ultrafine” particles and have long been the subjects of research regarding their health – and toxic – effects.31,32 Because new quantum effects or enhanced avail- ability may also be evident as coating or layer thicknesses, surface variations, and/or pores fall into this size range, nanomaterials include larger materials that have nano-sized layer thicknesses or surface features. Finally, because the upper limit of the size range is somewhat arbitrary, other definitions are in use that extend the upper limit to 1000 nm – that is, to 1 µm. Nanoparticles can be used as drug carriers and may alter a drug’s reactivity, strength, and, ultimately, its behavior in vivo.33–35 Advances in nanotechnology design and delivery can allow delivery of a drug to a targeted tissue, release of a drug at a controlled rate, treatments for drug detoxification,36 or detection of the early stages of a carcinogenic process.37,38 For instance, Doxil® and Abraxane® are two nanodrugs already approved and currently available.33 The unique properties or “nano” characteristics of a nanomaterial – including size, shape, charge, biocompatibility, solubility – can be critical factors in enabling and facilitating important biofunctional goals like tumor penetration.39 Following Vélez and Vélez40 and Maojo et al,41 we consider five main areas in nanomedicine to provide some relevant examples of applications. These areas introduce significant informational challenges. Delivery systems Nanoparticles (eg, dendrimers, liposomes, buckyballs, fuller- enes) can be designed as carriers to deliver genes, drugs, or molecules and to target specific parts of specific organisms (eg, organs, cells, molecules). By building detailed models and in silico computerized simulations, it is possible to design their structure and predict their properties.42 Delivery mechanisms include controlled release times, release rates, and detection systems to monitor effects of the drug or provide feedback. Nanodelivery – where nano-sized objects are transported through the body, target specific cells, and penetrate through cell and nuclear membranes – can improve the bioavailability, biocompatibility, therapeutic efficacy, stability, and solubility of drugs.43–46 Viruses, for example, are nano-sized and have evolved to perform exactly those same functions.47 We can differentiate between passive nanodelivery agents and those that can be triggered on arrival at the action site. Nanodelivery agents are designed to improve the availability of a poorly soluble or otherwise toxic bioactive compound (savaged drugs). To understand the value of nanodelivery devices in modern medicine, we should consider that an effective drug International Journal of Nanomedicine 2012:7