The phrase "an extended circulation" is correct and usable in written English.
It can be used in contexts related to the distribution or reach of something, such as a publication, information, or a physical object.
Example: "The magazine has achieved an extended circulation, reaching readers in multiple countries."
Alternatives: "a broader distribution" or "an increased reach".
Studies performed on mice with tumor of MDA-MB231 has shown an extended circulation time and enhanced tumor targeting with polyethylene oxide-modified polyepsilon-caprolactone [106].
An extended circulation also offers an opportunity to image the reticuloendothelial system (RES), the blood pool, and in some cases the lymph system.
An extended circulation lifetime allows them to take advantage of the enhanced permeability and retention effect (EPR), resulting in increased delivery to target sites.
An additional consideration of nanoparticle drug delivery for eventual clinical translation is ensuring an optimal size (10 100 nm) for extended circulation in the bloodstream and accumulation at disease sites.
It was reported that, in order to take full advantage of the EPR effect, the hydrodynamic diameter (HD) of the nanoparticles should be in the range of 10 to 200 nm, and the nanoparticles should be of a hydrophilic (polar or zwitterionic) surface coating for an extended blood circulation time and undesirable clearance by the immune system [40 42].
Nowadays, the application of LNP in other fields, such as gene therapy, has gained attraction. RNAi-lipid-based nanocarriers are able to provide protection from serum nucleases and extended circulation, which results in a higher access to the target tissue [ 38].
Thus water-soluble cyclic comb polymers join a growing list of polymer topologies that show greatly extended circulation times compared to their linear counterparts and provide alternative polymer architecture for use as drug carriers.
The hydrophilic PEG molecules have been used to reduce phagocytic capture of nanoparticles by cellular components of the immune system, leading to extended circulation and subsequent accumulation in tumors as a consequence of the enhanced permeability and retention (EPR) effect due to leaky vasculature and poor lymphatic drainage in tumors [11].
A rational solution to this challenge is to design nanocarriers with extended circulation times.
Extended circulation times can exploit the EPR effect to enhance transport of AuNPs to the tumor site, while in parallel, the particles' bound targeting molecules increase the rate of endocytotic uptake [22, 25].
An ideal drug delivery system for cancer therapy should be equipped with extended circulation, improved tumor targeting and controlled drug release, as well as low toxicity from the carrier.
