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Published on: April 16, 2019
Development of Dual Functional Nucleic Acid Delivery Nanosystem for DNA Induced Silencing of Bcl-2 Oncogene
Somayeh Karimi1, Mohamad Hassan Fouani2, Ahmad Moshaii1
1Department of Physics, Tarbiat Modares University, Tehran, Iran.
Introduction:
Cancer treatment using functionalized vehicles in order to block involved genes has attracted a remarkable interest. In this study, we investigated the cellular uptake and cytotoxic effects of three sizes of anti Bcl-2 DNAi-conjugated gold nanoparticles by MCF-7 cells.
Methods:
Three different sizes of gold nanoparticles were synthesized by citrate reduction method and after characterization, the nanoparticles were functionalized by Bcl-2 targeted DNAi. Cell internalization of the nanoparticles was analyzed by atomic absorption spectroscopy and light microscopy. The cytotoxic effects of the nanoparticles were investigated by MTT assay, flow cytometry and RT-PCR of the target gene.
Results:
While poor cell internalization of bare gold nanoparticles was observed, the results demonstrated that cellular uptake of DNAi-conjugated gold nanoparticles is completely size-dependent, and the largest nanoparticle (~42 nm) revealed the highest internalization rate compared to other sizes (~14 and ~26 nm). Experimental findings showed that the DNAi-conjugated gold nanoparticles induced apoptotic pathway by silencing of the targeted Bcl-2 gene. In addition, supplementary theoretical studies demonstrated that the 42 nm DNAi-conjugated gold nanoparticles have great photothermal conversion efficiency for treatment under external illumination and these nanoparticles can be induced further cytotoxic effect by approximately 10°C temperature elevations.
Conclusion:
Remarkable photothermal properties of DNAi-conjugated 42 nm Au-NPs in parallel with their high cell internalization and cytotoxic effects introduce them as potential dual functional anticancer nanosystems.
Insights
Gold nanoparticles functionalized with DNA inhibitors targeting Bcl-2 show size-dependent cellular uptake in cancer cells. The largest nanoparticles (~42 nm) exhibit enhanced internalization and potent anticancer effects via gene silencing and photothermal therapy.
Area of Science:
- Nanotechnology
- Biomedical Engineering
- Cancer Research
Background:
- Gene silencing is a promising cancer treatment strategy.
- Functionalized nanoparticles offer targeted drug delivery.
- Bcl-2 gene plays a crucial role in cancer cell survival.
Purpose of the Study:
- Investigate cellular uptake and cytotoxicity of anti-Bcl-2 DNA inhibitor-conjugated gold nanoparticles (Au-NPs).
- Evaluate the effect of Au-NP size on cellular internalization and anticancer efficacy.
- Explore the potential of these nanoparticles as dual-functional anticancer agents.
Main Methods:
- Synthesis and characterization of three sizes of Au-NPs (~14, ~26, ~42 nm).
- Functionalization of Au-NPs with Bcl-2 targeted DNA inhibitor (DNAi).
- Assessment of cellular uptake (atomic absorption spectroscopy, light microscopy) and cytotoxicity (MTT assay, flow cytometry, RT-PCR).
- Evaluation of photothermal properties and temperature elevation effects.
Main Results:
- Cellular uptake of DNAi-conjugated Au-NPs is size-dependent, with ~42 nm particles showing the highest internalization.
- DNAi-conjugated Au-NPs induce apoptosis by silencing the Bcl-2 gene.
- ~42 nm DNAi-conjugated Au-NPs exhibit significant photothermal conversion efficiency, capable of increasing temperature by ~10°C for enhanced cytotoxicity.
Conclusions:
- DNAi-conjugated 42 nm Au-NPs demonstrate high cell internalization and potent cytotoxic effects.
- These nanoparticles possess remarkable photothermal properties, enabling dual-mode cancer therapy.
- The developed Au-NPs represent promising dual-functional anticancer nanosystems.
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