The objective of the Journal of Nanoparticle Research is to disseminate knowledge of the physical chemical and biological phenomena and processes in structures that have at least one lengthscale ranging from molecular to approximately 100 nm (or submicron in some situations) and exhibit improved and novel properties that are a direct result of their small size. Nanoparticle research is a key component of nanoscience nanoengineering and nanotechnology. The focus of the Journal is on the specific concepts properties phenomena and processes related to particles tubes layers macromolecules clusters and other finite structures of the nanoscale size range. Synthesis assembly transport reactivity and stability of such structures are considered. Development of in-situ and ex-situ instrumentation for characterization of nanoparticles and their interfaces should be based on new principles for probing properties and phenomena not well understood at the nanometer scale. Modeling and simulation may include atom-based quantum mechanics; molecular dynamics; single-particle multi-body and continuum based models; fractals; other methods suitable for modeling particle synthesis assembling and interaction processes. Realization and application of systems structures and devices with novel functions obtained via precursor nanoparticles is emphasized. Approaches may include gas- liquid- solid- and vacuum-based processes size reduction chemical- and bio-self assembly. Contributions include utilization of nanoparticle systems for enhancing a phenomenon or process and particle assembling into hierarchical structures as well as formulation and the administration of drugs. Synergistic approaches originating from different disciplines and technologies and interaction between the research providers and users in this field are encouraged. The content of the Journal is at the intersection of various scientific and technological areas including particle technology colloids aerosols multiphase systems solid state physics chemistry and macromolecular science materials engineering pharmacy microcontamination emission control environment and health effects biotechnology and biomedicine sensors and electronics. Journal of Nanoparticle Research publishes: Original full scientific papers (about 3/4 of its contents) Letters to the editor for timely dissemination of scientific breakthroughs (in the section on 'Brief Communications'). An accelerated review process will insure a short publication cycle for brief communications. Short technical statements on novel technologies and applications (in the section on 'Technology and Applications'). A regular editorial/commentary page called 'Perspectives' with the author's picture will be included in each issue. The Editor-in-Chief will coordinate this activity. The Journal