ABSTRACT
Drug delivery nanoplatforms have been applied in bioimaging, medical diagnosis, drug delivery and medical therapy. However, insolubility, toxicity, instability, nonspecific targeting and short retention of many hydrophobic drugs limit their extensive applications. Herein, we have constructed a passive targeting and long retention therapeutic nanoplatform of core-shell gefitinib/poly (ethylene glycol)-polytyrosine nanocomplexes (Gef-PY NCs). The Gef-PY NCs have good water-solubility, non-toxicity (correspond to 1/10 dosage of effective gefitinib (hydrochloride) (Gef·HCl) (normal drug administration and slow-release) and high stability (120 days, 80% drug retention at 4 or 25 °C). The core-shell Gef-PY NCs present unexpected kidney targeting and drug slow-release capacity (ca. 72 h). The good water-solubility, non-toxicity and high stability of Gef-PY NCs effectively solve the bottleneck question that Gef-based therapy could be used only in intraperitoneal injection due to its insolubility and severe toxicity. Such excellent properties (e.g., water-solubility, non-toxicity, high stability, kidney targeting and long retention) of Gef-PY NCs create their prominent anti-fibrosis capabilities, such as decreasing approximately 40% tubulointerstitial fibrosis area and 68% expression of collagen I within 7 days. This therapeutic efficacy is well-matched with that of 10 times the dosage of toxic Gef·HCl. It is very hopeful that Gef-PY NCs could realize clinical applications and such a strategy offers an effective route to design high-efficiency treatments for kidney- and tumor-related diseases.
Subject(s)
Antineoplastic Agents , Amino Acids , Drug Delivery Systems , Gefitinib , WaterABSTRACT
BACKGROUND: Virtual radiographic simulation has been found educationally effective for students to practice their clinical examinations remotely or online. A free available virtual simulator-ImaSim has received particular attention for radiographic science education because of its portability, free of charge and no constrain of location and physical facility. However, it lacks evidence to validate this virtual simulation software to faithfully reproduce radiographs comparable to that taken from a real X-ray machine to date. OBJECTIVE: To evaluate image quality of the virtual radiographs produced by the ImaSim. Thus, the deployment of this radiographic simulation software for teaching and experimental studying of radiography can be justified. METHODS: A real medical X-ray examination machine is employed to scan three standard QC phantoms to produce radiographs for comparing to the corresponding virtual radiographs generated by ImaSim software. The high and low range of radiographic contrast and comprehensive contrast-detail performance are considered to characterize the radiographic quality of the virtual simulation software. RESULTS: ImaSim software can generate radiographs with a contrast ranging from 30% to 0.8% and a spatial resolution as low as 0.6mm under the selected exposure setting condition. The characteristics of contrast and spatial resolution of virtual simulation generally agree with that of real medical X-ray examination machine. CONCLUSION: ImaSim software can be used to simulate a radiographic imaging process to generate radiographs with contrast and detail detectability comparable to those produced by a real X-ray imaging machine. Therefore, it can be adopted as a flexible educational tool for proof of concept and experimental design in radiography.
