Engineered nanoparticles in cancer therapy

Intense research has led to a more comprehensive understanding of cancer at the genetic, molecular, and cellular levels providing an avenue for methods of increasing antitumor efficacy of drugs while reducing systemic side effects. Nanoparticulate technology is of particular use in developing a new generation of more effective cancer therapies capable of overcoming the many biological, biophysical, and biomedical barriers that the body stages against a standard intervention. Nanoparticles show much promise in cancer therapy by selectively gaining access to tumor due to their small size and modifiability. Typically, though not exclusively, nanoparticles are defined as submicroscopic particles between 1 and 100 nm. Nanoparticles are formulated out of a variety of substances and engineered to carry an array of substances in a controlled and targeted manner. Nanoparticles are prepared to take advantage of fundamental cancer morphology and modes of development such as rapid proliferation of cells, antigen expression, and leaky tumor vasculature. In cancer treatment and detection nanoparticles serve many targeted functions in chemotherapy, radiotherapy, immunotherapy, immunodetection, thermotherapy, imaging, photodynamic therapy, and anti-angiogenesis. Not only are modifying agents allowing for greater and more accurate tumor targeting, they are also aiding in the crossing of biophysical barriers such as the blood brain barrier there by reducing peripheral effects and increasing the relative amount of drug reaching in the brain. Moreover, multifunctional nanoparticles perform many of these tasks simultaneously such as targeted delivery of a potent anticancer drug at the same time as an imaging material to visualize the effectiveness of the drug utilized for treatment follow-up. In this review, several recent US and World patents developing and modifying nanoparticles for the detection, analysis, and treatment of cancer are discussed.