Intelligent drug delivery systems for the treatment of solid tumors

Abstract

Abstract:The rationale for the use of nanoparticle formulations to treat cancer is based on the ability of these particles to facilitate selective delivery of drugs to the tumor site, reducing adverse effects and improving therapeutic outcomes. Current clinically approved nanomedicines have managed to reduce adverse effects significantly but the increase in overall survival is modest in many cases. Therefore, even though the goal of a better quality of life for the cancer patients has been achieved in large part, the increase in life expectancy still remains a critical challenge. Abnormalities in the tumor micro-environment prevent homogeneous distribution of nanoparticles to the interior of the tumor, decreasing the efficacy of the drug. Intelligent drug delivery systems offer new hope for overcoming these physiological barriers posed by the tumor and have the potential to provide more effective treatments. This review discusses the barriers to the delivery of nanomedicines to solid tumors, suggests design considerations that could optimize delivery and reviews promising intelligent drug delivery systems that have been developed to date.

Heating ability modulation by clustering of magnetic particles for precision therapy and diagnosis

“…As a matter of fact, many different sizes of iron oxide nanoparticles have been considered for practical, i.e., in-vivo applications of magnetic hyperthermia [7]. On the basis of physiology considerations, particle diameters between 12 and 50 nm have been indicated as ideal for application in biomedicine, the lower limit being dictated by the requirement that the particles should be large enough so that they do not cross the pores of a blood vessel wall, which are typically smaller than 12 nm [71]. The upper limit is instead defined with reference to the ease of transport in the blood circulation [71].…”

“…On the basis of physiology considerations, particle diameters between 12 and 50 nm have been indicated as ideal for application in biomedicine, the lower limit being dictated by the requirement that the particles should be large enough so that they do not cross the pores of a blood vessel wall, which are typically smaller than 12 nm [71]. The upper limit is instead defined with reference to the ease of transport in the blood circulation [71]. Let us stress, however, that magnetite particles larger than 18-20 nm (depending on the parameter values) are basically ineffective as heaters of a living tissue when submitted to a radio-frequency magnetic field whose amplitude is sufficiently small to be tolerated by patients [10].…”

Molecular Imaging in Nanotechnology and Theranostics

“…reticuloendothelial system or kidneys), as can many tumors through the ‘enhanced permeability and retention’ (EPR) effect; (3) Nanoparticles can respond to their microenvironment or to external stimuli to provide therapy and contrast only where needed [3]; and (4) different types of therapy can be elicited by the Nanoparticles. These features render Nanoparticles as peerless imaging agents using traditional medical imaging, and enable the development of new modalities and theranostic applications.…”