Related Experiment Video
Updated: May 17, 2026
07:13
Biomolecular Imaging of Cellular Uptake of Nanoparticles using Multimodal Nonlinear Optical Microscopy
Published on: May 16, 2022
Kinetic quantification of protein polymer nanoparticles using non-invasive imaging
1Department of Pharmacology and Pharmaceutical Sciences, University of Southern California, Los Angeles, CA 90033-9121, USA.
Integrative Biology : Quantitative Biosciences From Nano to Macro
|October 25, 2012
Summary
Protein polymers form nanoparticles for cancer nanomedicine. Positron emission tomography (PET) imaging tracked these elastin-like polypeptide (ELP) nanoparticles, revealing molecular weight, not nanostructure, dictates their pharmacokinetics and tumor accumulation.
Area of Science:
- Biomaterials Science
- Nanotechnology
- Molecular Imaging
Background:
- Protein polymers, specifically elastin-like polypeptides (ELPs), self-assemble into nanoparticles with potential as cancer nanomedicines.
- Positron emission tomography (PET) offers sensitive and quantitative molecular imaging crucial for tracking nanotherapeutics.
Purpose of the Study:
- To investigate the in vivo tracking of ELP-based protein polymer nanoparticles using microPET imaging over several days.
- To develop and apply a pharmacokinetic model to analyze nanoparticle distribution and behavior.
Main Methods:
- Site-specific conjugation of polypeptides with AmBaSar chelator for complexation with Copper-64 ((64)Cu).
- MicroPET imaging in an orthotopic breast cancer model to track four different ELP-based protein polymers.
- Development of a six-compartment image-driven pharmacokinetic model for data analysis.
Main Results:
- Nanoparticle formation minimally affected pharmacokinetics or tumor accumulation compared to free ELPs of similar molecular weight.
- ELP molecular weight was the primary determinant of polymer fate, with longer ELPs exhibiting significantly longer circulation half-lives.
- Long ELPs (74 kD) had an 8.7-hour half-life, while short ELPs (37 kD) had a 2.1-hour half-life.
Conclusions:
- ELP molecular weight, rather than nanostructure, is the key factor governing the pharmacokinetic behavior of these protein polymer nanoparticles.
- ELP-based protein polymers represent a promising platform for developing theranostic nanoparticles that can be monitored with clinical PET scanners.
