Polymeric Nanoparticles Enable Targeted Visualization of Drug Delivery in Breast Cancer

Area of Science:

• Biomaterials Science
• Nanotechnology
• Cancer Therapeutics

Background:

• Targeted drug delivery systems are crucial for improving cancer treatment efficacy and reducing side effects.
• Polymeric nanoparticles offer a versatile platform for encapsulating and delivering therapeutic agents.
• Developing stimuli-responsive systems that release drugs specifically at the tumor site is a key challenge.

Purpose of the Study:

• To coencapsulate fluorocoxib Q (FQ) and chemocoxib A (CA) into novel micellar nanoparticles (FQ-CA-NPs) using a PPS-b-POEGA diblock polymer.
• To evaluate the cellular uptake, intracellular release, and therapeutic efficacy of FQ-CA-NPs in breast cancer models.
• To assess the in vivo targeting, ROS-mediated cargo release, and fluorescence activation of FQ-CA-NPs in a murine breast tumor model.

Main Methods:

• Synthesis and characterization of PPS135-b-POEGA17 diblock copolymer nanoparticles.
• In vitro assessment of nanoparticle uptake and intracellular cargo release in 4T1 cancer cells using fluorescence microscopy.
• In vitro cytotoxicity assays on human mammary epithelial cells (HMECs) and 4T1 cells.
• In vivo studies involving intravenous administration of FQ-CA-NPs in mice bearing breast tumors, including fluorescence imaging and ex vivo tissue analysis (LC-MS/MS, H&E staining).

Main Results:

• FQ-CA-NPs exhibited a hydrodynamic diameter of ~109 nm and a zeta potential of ~-1.6 mV.
• Enhanced cellular uptake and intracellular release of FQ and CA were observed in 4T1 cells compared to celecoxib controls.
• FQ-CA-NPs demonstrated selective toxicity towards 4T1 cancer cells with no significant impact on HMECs.
• In vivo studies showed ROS-mediated cargo release, FQ fluorescence activation, and increased fluorescence in breast tumors, indicating targeted delivery and retention.
• Ex vivo analysis confirmed enhanced cargo delivery and retention in tumor tissues compared to control groups.

Conclusions:

• Coencapsulation of FQ and CA into PPS-b-POEGA nanoparticles provides a promising strategy for targeted breast cancer therapy.
• The FQ-CA-NPs exhibit ROS-sensitive release, enabling fluorescence-guided drug delivery and visualization of tumor targeting.
• The developed nanoparticles demonstrate significant in vivo therapeutic effects, including tumor growth inhibition, with minimal toxicity to normal cells.