Heparin-appended polycaprolactone core/corona nanoparticles for site specific delivery of 5-fluorouracil

The Novel 5-Fluorouracil Loaded Ruthenium-based Nanocarriers Enhanced Anticancer and Apoptotic Efficiency while Reducing Multidrug Resistance in Colorectal Cancer Cells

Recently, nanocarriers have been made to eliminate the disadvantages of chemotherapeutic agents by nanocarriers. Nanocarriers show their efficacy through their targeted and controlled release. In this study, 5-fluorouracil (5FU) was loaded into ruthenium (Ru)-based nanocarrier (5FU-RuNPs) for the first time to eliminate the disadvantages of 5FU, and its cytotoxic and apoptotic effects on HCT116 colorectal cancer cells were compared with free 5FU. 5FU-RuNPs with a size of approximately 100 nm showed a 2.61-fold higher cytotoxic effect compared to free 5FU. Apoptotic cells were detected by Hoechst/propidium iodide double staining, and the expression levels of BAX/Bcl-2 and p53 proteins, in which apoptosis occurred intrinsically, were revealed. In addition, 5FU-RuNPs was also found to reduce multidrug resistance (MDR) according to BCRP/ABCG2 gene expression levels. When all the results were evaluated, the fact that Ru-based nanocarriers alone did not cause cytotoxicity proved that they were ideal nanocarriers. Moreover, 5FU-RuNPs did not show any significant effect on the cell viability of normal human epithelial cell lines BEAS-2B. Consequently, the 5FU-RuNPs synthesized for the first time may be ideal candidates for cancer treatment because they can minimize the potential drawbacks of free 5FU.

The use of 5-fluorouracil-loaded nanobubbles combined with low-frequency ultrasound to treat hepatocellular carcinoma in nude mice

OBJECTIVE

This study aimed to investigate the therapeutic effects of 5-fluorouracil (5-FU)-loaded nanobubbles irradiated with low-intensity, low-frequency ultrasound in nude mice with hepatocellular carcinoma (HCC).

METHODS

A transplanted tumor model of HCC in nude mice was established in 40 mice, which were then randomly divided equally into four groups: group A (saline), group B (5-FU-loaded nanobubbles), group C (5-FU-loaded nanobubbles with non-low-frequency ultrasound), and group D (5-FU-loaded nanobubbles with low-frequency ultrasound). The tumor size in each mouse was observed via ultrasound before and after the treatments. Inhibition of the tumor growth in each group was compared, and survival curves were generated. Tumor tissues were removed to determine the apoptotic index using the TUNEL method and quantitative analysis. Tumor tissues with CD34-positive microvessels were observed by immunohistochemistry, and the tumor microvessel densities were calculated.

RESULTS

The growth rate of the tumor volumes in group D was significantly slower than that in the other groups, while the tumor inhibition rates and apoptotic index in group D were significantly higher than those of the other groups. The number of microvessels staining positive for CD34 was decreased in group D. Therefore, group D presented the most significant inhibitory effects.

CONCLUSIONS

Therefore, 5-FU-loaded nanobubbles subjected to irradiation with low-frequency ultrasound could further improve drug targeting and effectively inhibit the growth of transplanted tumors, which is expected to become an ideal drug carrier and targeted drug delivery system for the treatment of HCC in the future.

PCL and PCL-based materials in biomedical applications

Biodegradable polymers have met with an increasing demand in medical usage over the last decades. One of such polymers is poly(ε-caprolactone) (PCL), which is a polyester that has been widely used in tissue engineering field for its availability, relatively inexpensive price and suitability for modification. Its chemical and biological properties, physicochemical state, degradability and mechanical strength can be adjusted, and therefore, it can be used under harsh mechanical, physical and chemical conditions without significant loss of its properties. Degradation time of PCL is quite long, thus it is used mainly in the replacement of hard tissues in the body where healing also takes an extended period of time. It is also used at load-bearing tissues of the body by enhancing its stiffness. However, due to its tailorability, use of PCL is not restricted to one type of tissue and it can be extended to engineering of soft tissues by decreasing its molecular weight and degradation time. This review outlines the basic properties of PCL, its composites, blends and copolymers. We report on various techniques for the production of different forms, and provide examples of medical applications such as tissue engineering and drug delivery systems covering the studies performed in the last decades.