Related Experiment Video
Updated: Jun 23, 2026
Analysis of Targeted Viral Protein Nanoparticles Delivered to HER2+ Tumors
Published on: June 18, 2013
PET-MR Guided, Pre-targeted delivery to HER2(+) Breast Cancer Model
Ge Si1,2, Sudath Hapuarachchige3,2, Wojciech G Lesniak2
1Department of Chemical and Biomolecular Engineering, The Johns Hopkins University, 3400 N. Charles Street, Baltimore, MD 21218, USA.
Purpose:
HER2(+) metastatic breast cancer (mBC) is one of the most aggressive and lethal cancer types among females. While initially effective, targeted therapeutic approaches with trastuzumab and pertuzumab antibodies and antibody-drug conjugates (ADC) lack long-term efficacy against HER2(+) mBC and can cause severe systemic toxicity due to off-target effects. Therefore, the development of novel targeted delivery platforms that minimize toxicity and increase therapeutic efficacy is critical to the treatment of HER2(+) breast cancer (BC). A pretargeting delivery platform can minimize the non-specific accumulation and off-target toxicity caused by traditional one-step delivery method by separating the single delivery step into a pre-targeting step with high-affinity biomarker binding ligand followed by the subsequent delivery step of therapeutic component with fast clearance. Each delivery component is functionalized with bioorthogonal reactive groups that quickly react in situ, forming cross-linked clusters on the cell surface, which facilitates rapid internalization and intracellular delivery of therapeutics.
Procedures:
We have successfully developed a click chemistry-based pretargeting platform for HER2(+) BC enabling PET-MR image guidance for reduced radiation dose, high sensitivity, and good soft tissue contrast. Radiolabeled trastuzumab and superparamagnetic iron-oxide carriers (uSPIO) were selected as pretargeting and delivery components, respectively. HER2(+) BT-474 cell line and corresponding xenografts were used for in vitro and in vivo studies.
Results:
An enhanced tumor accumulation as well as tumor-to-organ accumulation ratio was observed in pretargeted mice up to 24 h post uSPIO injection. A 40% local T1 decrease in the pretargeted mice tumor was observed within 4 h, and an overall 15% T1 drop was retained for 24 h post uSPIO injection.
Conclusions:
Prolonged tumor retention and increased tumor-to-organ accumulation ratio provided a solid foundation for pretargeted image-guided delivery approach for in vivo applications.
Insights
A novel pretargeting platform enhances drug delivery for HER2(+) metastatic breast cancer by minimizing toxicity. This approach improves tumor accumulation and retention, paving the way for image-guided therapies.
Area of Science:
- Oncology
- Biomedical Engineering
- Radiology
Background:
- HER2(+) metastatic breast cancer (mBC) is aggressive, with current therapies lacking long-term efficacy and causing toxicity.
- Novel targeted delivery platforms are crucial for improving efficacy and reducing side effects in HER2(+) BC treatment.
Approach:
- Developed a click chemistry-based pretargeting platform for HER2(+) breast cancer (BC).
- Utilized radiolabeled trastuzumab as the pretargeting component and ultra-small superparamagnetic iron-oxide carriers (uSPIO) as the delivery component.
- Employed PET-MR imaging for guidance, enabling reduced radiation dose and enhanced contrast.
Key Points:
- Demonstrated enhanced tumor accumulation and improved tumor-to-organ accumulation ratio up to 24 hours post-injection in pretargeted mice.
- Observed a 40% local T1 decrease in tumors within 4 hours, with a sustained 15% drop for 24 hours.
- Validated the platform using HER2(+) BT-474 cell lines and xenografts for in vitro and in vivo studies.
Conclusions:
- The pretargeting platform shows prolonged tumor retention and increased tumor-to-organ accumulation.
- This approach provides a foundation for image-guided delivery, minimizing toxicity and maximizing therapeutic impact in HER2(+) BC.
