oa Editorial [Hot Topic: Nanotechnology Enables Superior Medical Therapies (Guest Editors: Marianna Foldvari & Mahmoud Elsabahy)]

Nanomedicine is a new term, used to define the medical applications of nanotechnology. It encompasses the next era in drug delivery and diagnostics and imaging of health and disease conditions. This Special Issue is intended to bring to the forefront some major issues on regulatory challenges, examples for nanopharmaceutical product concepts based on nanoscale materials and evaluation of their safety or potential adverse effects. The urgent need for radical improvement of health and disease management is widely recognized. According to a comprehensive review by PriceWaterhouseCoopers, Pharma 2020: The vision. Which path will you take?, worldwide demand for effective treatments and prophylactics is steadily increasing due to several factors, including 1. global population pressures (projected population of 7.6 billion in 2020, from 6.5 billion in 2005); 2. changing demographics (people 65+ years will comprise about 9.4% of the total population by 2020, compared with 7.3% in 2005); (3) emergence of new pathogens (including bioterrorism) and antibiotic-resistant microorganisms; (4) climate change resulting in an increase in and spread of malaria, respiratory pathogens, common bacteria such as Salmonella and Campylobacter, the main cause of gastroenteritis, and E. coli; and (5) socioeconomic changes in the developing world leading to disease burden patterns resembling those in the developed world. Pharmaceutical companies have begun to struggle with providing innovative drugs for unmet medical needs. This innovation deficit, and the rising interest in personalized medicine, has slowed the pipeline of drug discovery, suggesting that current methods of developing blockbuster drugs may no longer be feasible. In 2007, only 19 new drugs/biologics were approved, the fewest since 1983. Low pharmaceutical R&D productivity, the complexity of applying genomic, proteomic and metabolomic data, the focus on a single molecule per disease, instead of targeting specific diseases with the right combination of treatment, will initiate a shift in global approaches to disease treatment. Additionally, the cost of non-compliance, a staggering $77-300 billion a year in the US alone, and the shift in attitude toward disease prevention necessitate better patient monitoring, personalized therapies, development of more effective vaccines and significant involvement of patients in management of their personal health and treatment regimens. Economic considerations alone would indicate that increased effectiveness is necessary to address the growing needs of patients and society. It is quite certain that the answer to the question of what will take us globally to the next level of effectiveness lies in the application of nanotechnology to health care. Significant initiatives worldwide are indicative of the already happening revolution in nanomedicine research and its translation to the clinic. The highlights of topics in this issue are as follows: Ushering nanomedicines toward clinical applications will require concerted efforts between researchers, pharmaceutical developers and regulatory agencies. The issue's first paper by Bawa emphasizes the need for appropriate regulatory guidance in the area of nanomedicines and enlists the challenges the Food and Drug Administration (FDA) is facing regarding the approval of nanomedicines. He also challenged the validity of evaluating nanoproducts using existing regulations and suggests the need for development of ‘nano’-specific guidelines. Finally, he provided some solutions and suggestions on regulatory requirements for nanomedicines. Applications of nanotechnology are reviewed in several therapeutic areas, such as gene therapy, cancer therapy/immunotherapy and vaccines. Elsabahy and coworkers reviewed the applications of nanoparticles as carriers for nucleic acids. They highlighted the key challenges and future directions of the non-viral vectors for gene therapy. Wong and coworkers reviewed the applications of nanomedicines in cancer therapy. They summarized the recent advances in the design of nanoparticles in cancer therapy. Then, continuing in the same subject, Sengupta and coworkers, reviewed the different cellular signaling pathways implicated in the pathogenesis of cancer and explained how they can be exploited as novel drug targets. They described how these novel drugs can be possibly merged with nanotechnology, to preferentially target the tumor. In a two-part review, Lavasanifar et al. explains the use of targeted nanoparticles in cancer immunotherapy and in imaging the anticancer immune responses. In the first part, a review of the immunotherapeutic strategies that aim to deliver tumor antigens specifically to dendritic cells is presented, including how nano-sized particulate delivery systems can deliver these antigens to dendritic cells in a targeted and specific manner. In the second part, devoted to improvements in imaging of nanomedicine delivery, the potential role of nanoscopic devices in delivering tracking molecules to dendritic cells for molecular imaging is presented. Toth and coworkers showed how nanotechnology could replace the classical vaccines by delivering immunogenic subunits derived from a particular pathogen. They reviewed the use of nanoparticles of different compositions for the delivery of peptide vaccines. As an important component in nanomedicine development, Gu and coworkers reviewed the use of CH50 as a hemolytic complement consumption assay for evaluation of nanoparticles and blood plasma protein interaction. This assay can work as a predictor of in vivo behavior and helps in understanding the mechanisms through which nanoparticles interact with the complement system of innate immunity, which could be very helpful in the nanoparticles design. In addition, they compared this method with alternative complement measurement techniques. Several specific nanomedicine designs are presented in original research papers and intend to highlight advances in noninvasive and targeted applications. Badea et al. introduced an example of a novel non-viral vector, gemini nanoparticles, for the delivery of plasmid DNA. In this study, they investigated the use of novel amino acid-substituted gemini surfactant-based nanoparticles as gene nanocarriers for mucosal applications. Foldvari et al. investigated biphasic vesicles as dermal delivery system for interferon alpha designed for the treatment of human papillomavirus infections. In this study, topical application in human volunteers and patients indicated that these novel delivery systems can deliver clinically significant levels of interferon alpha across intact human skin and wart tissue without the need for needles or other invasive methods. Romero and coworkers reported on the use of archaeosomes for oral drug delivery. They showed that these new delivery systems are superior to conventional liposomes and that they are preferentially taken up by the M cells as compared to liposomes. This Special Issue of Current Drug Delivery is a tiny snapshot of examples of the significant efforts made by the scientific and clinical nanomedicine community that is dynamically shaping the future of medical diagnosis, treatment and prevention of diseases.