<p>Doxorubicin-Loaded Carbon Dots Lipid-Coated Calcium Phosphate Nanoparticles for Visual Targeted Delivery and Therapy of Tumor</p>

Abstract

Background: Carbon dots (CDs) have attracted extensive attention in recent years because of their high biocompatibility and unique optical property. But they could not be well applied in the drug delivery system to enable distribution in tumor sites with their low pH sensitivity. They are barriers for drug delivery. CDs as an imaging proper were conjugated with doxorubicin (DOX) lipid-coated calcium phosphate (LCP) nanoparticle, for a pH-sensitive nanocarrier and delivery of the antitumor drugs. Materials and Methods: CDs were prepared by one-step hydrothermal treatment of citric acid and ethylenediamine. The nanoparticles were simply prepared by using microemulsion technology to form calcium phosphate (CaP) core and further coated with cationic lipids. Results: The structure was characterized by FTIR, XRD and TEM. In vitro release study revealed that DOX-CDs@LCP was pH dependent. The cytotoxicity assay demonstrated that it exhibited enhanced efficiency compared to the control group (DOX-CDs), but weaker than free DOX. The cellular uptake revealed that these pH-sensitive nanoparticles could be taken up effectively and deliver DOX into the cytoplasm to reach antitumor effect. The fluorescence imaging indicated that DOX-CDs@LCP mostly distributed in the tumor region due to the enhanced permeability and retention effect (EPR) to reduce its systematical toxicity. Importantly, an antitumor activity study demonstrated that the DOX-CDs@LCP nanoparticles had higher antitumor activity than any other groups and lower toxicity. The results showed that LCP could significantly promote the release in tumor microenvironment due to pH-response. The DOX-CDs could enhance load capacity and reduce drug premature releasing; real-time tracking of efficacy as confocal imaging contrast agent. Thus, DOX-CDs@LCP had antitumor capacity and lower systematic toxicity in tumor therapy. Conclusion: DOX-CDs@LCP were proven as a promising tumor pH-sensitive and imaging-guided drug delivery system for liver cancer chemotherapy.

Mapping the time dependent DNA fragmentation caused by doxorubicin loaded on PEGylated carbogenic nanodots using fluorescence lifetime imaging and superresolution microscopy

“…23 The study by Yang et al showed the nuclear delivery of DOX using nuclear targeting aptamer moiety functionalized carbon dots, 20 and Hailing et al used the PEI polymer to achieve the same. 24 Except for a few studies conducted in the in vivo environment 17,19,24–26 and our study using fluorescence lifetime imaging (FLIM), 27 most of the studies ignore the effect of the protein corona.…”

Recent Advances in Functional Carbon Quantum Dots for Antitumour

“…38 Due to their small structure, CQDs can be trapped in tumour sites by an enhanced permeability and retention effect (EPR). 39,40 In normal tissues, the microvascular endothelial space is dense and intact, and CQDs are difficult to penetrate the vascular wall, while in solid tumor tissues, blood vessels are abundant, and the wide vascular wall space, poor structural integrity and missing lymphatic return result in high selective permeability and retention of large CQDs. 41,42 Therefore, EPR effect promotes the selective distribution of CQDs in tumor tissues, which can increase antitumour efficacy and reduce systemic side effects.…”

Morphology of hybrid doxorubicin delivery systems (dextran sulfate-coated CaCO3 vaterites) in human blood plasma

“…In the recent years, a large number of nano-and submicron-sized delivery systems for anti-cancer drugs have been developed [3]. The basic structure of carriers may vary; bio-organic objects are commonly used as carriers: exosomes [4], liposomes [5], dendrimers, macrophages [6], micelles [7], as well as inorganic substances, e.g., carbon nanotubes [8], calcium phosphates [9,10], SiO 2 [11], and CaCO 3 [12]. It should be noted that manufacturing of most DS is rather laborious; in a number of cases, it is necessary to synthesize complex polymers.…”