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Updated: Sep 5, 2025
Using In Vitro Live-cell Imaging to Explore Chemotherapeutics Delivered by Lipid-based Nanoparticles
Published on: November 1, 2017
Mapping the time dependent DNA fragmentation caused by doxorubicin loaded on PEGylated carbogenic nanodots using
Chethana Rao1, Shagun Sharma1, Richa Garg1
1School of Basic Sciences, Indian Institute of Technology (IIT) Mandi, H.P-175075, India. chayan@iitmandi.ac.in.
Abstract:
Doxorubicin is an anthracycline drug most commonly used in cancer therapy. It intercalates with the nuclear DNA and induces toxicity by causing DNA breaks and histone eviction. However, the kinetics of its action on the nucleus has not been mapped effectively. This study shows successful PEGylation and DOX loading through π-π interaction onto carbogenic fluorescent nanodots (FNDs), which have an affinity for the nucleolus. Then the drug release from the nanoparticle and its action on the nuclear environment were aptly mapped using both fluorescence lifetime imaging and superresolution radial fluctuation (SRRF) techniques. Here for the first time, the nuclear degradation kinetics caused by the released DOX from the FNDs as a result of DNA double-strand breaks and histone eviction was visualized. This led to the observation of decreasing length, breadth, and complex structure of the nuclear clusters from 6 h to 24 h, resulting in isolated cluster visualization. However, the superresolution images for free DOX and untreated cells reveal no such drastic effects at the same concentration and time points, unlike DOX loaded particles.
Insights
This study visualizes doxorubicin (DOX) drug release from fluorescent nanodots (FNDs) and its nuclear degradation effects. DOX-loaded FNDs caused significant nuclear changes, unlike free DOX.
Area of Science:
- Biochemistry
- Nanotechnology
- Cell Biology
Background:
- Doxorubicin (DOX) is a key chemotherapy drug that damages nuclear DNA.
- The precise kinetics of DOX's nuclear action and degradation remain poorly understood.
- Nanoparticle drug delivery systems offer potential for targeted cancer therapy.
Purpose of the Study:
- To develop and characterize PEGylated fluorescent nanodots (FNDs) for doxorubicin (DOX) delivery.
- To visualize and quantify the nuclear degradation kinetics induced by DOX released from FNDs.
- To compare the nuclear effects of DOX-loaded FNDs with free DOX.
Main Methods:
- PEGylation of carbogenic fluorescent nanodots (FNDs) and loading of DOX via π-π interaction.
- Utilizing fluorescence lifetime imaging and superresolution radial fluctuation (SRRF) microscopy.
- Monitoring changes in nuclear cluster morphology and structure over time (6-24 hours).
Main Results:
- Successful development of DOX-loaded FNDs with nucleolar affinity.
- Visualization of DNA double-strand breaks and histone eviction caused by released DOX.
- Observed decrease in nuclear cluster size and complexity, leading to isolated structures.
- DOX-loaded FNDs induced significant nuclear degradation, unlike free DOX at equivalent concentrations.
Conclusions:
- Fluorescent nanodots provide an effective platform for visualizing doxorubicin's nuclear degradation kinetics.
- The study demonstrates the potential of FNDs for targeted drug delivery and monitoring therapeutic effects.
- This approach offers novel insights into the spatiotemporal dynamics of chemotherapy-induced nuclear damage.
