Nanoparticle Breakthrough Enhances Biomedical Imaging and Cancer Treatment

A team of researchers at the University of São Paulo’s São Carlos Institute of Physics (IFSC-USP) in Brazil has made significant advancements in biomedical imaging and cancer therapy through the engineering of hydroxyapatite nanoparticles. These nanoparticles, enhanced with intrinsic luminescent properties, offer a biocompatible and cost-effective alternative to traditional imaging agents and drug delivery systems.

Hydroxyapatite Nanoparticles with Enhanced Luminescence

The Nanomedicine and Nanotoxicology Group (GNano) at IFSC-USP has developed a method to transform hydroxyapatite, a bioceramic material, into nanoparticles with significantly improved intrinsic luminescence. This enhancement is achieved by incorporating carbonate groups during the synthesis process, increasing the concentration of crystalline defects within the material’s structure. These defects act as luminescent centers, boosting the material’s ability to emit light. Source

“We’ve demonstrated that the incorporation of carbonate groups into the hydroxyapatite structure increases the concentration of crystal defects, which are responsible for enhancing the intrinsic luminescence of the material,” explained Thales Rafael Machado, a researcher involved in the study. “After functionalization with citrate, which improves colloidal stability in aqueous media, these calcium phosphate nanoparticles can be used as luminescent agents for cellular bioimaging.” Source

The researchers demonstrated the bioimaging capability by visualizing the internalization of the nanoparticles into cells using confocal fluorescence microscopy, relying solely on their intrinsic luminescence. Cellular internalization was also confirmed through flow cytometry, based on the luminescent signal of the particles, and biocompatibility was assessed via cellular cytotoxicity assays. Source

Targeted Cancer Therapy with Gemcitabine

In a parallel study, the GNano team developed a dual pH-responsive system for delivering gemcitabine, a chemotherapy drug commonly used to treat cancers like pancreatic cancer. The system is designed to keep the drug inactive in normal physiological conditions, such as within the bloodstream, and release it only in the more acidic environments characteristic of tumor regions. This targeted approach aims to increase bioavailability and therapeutic potential. Source

To further enhance targeting, the nanoparticles were functionalized with folic acid, which binds to receptors found on many tumor cells. This combination of controlled release and active targeting promotes higher drug concentrations in cancer cells, potentially reducing side effects on healthy tissues. Source

The researchers achieved this by creating a prodrug, linking gemcitabine to a biocompatible polymer called carboxymethylcellulose. This protects the drug from premature degradation and ensures its release only in acidic environments. The same polymer also stabilizes the calcium phosphate nanoparticles in suspension, preventing them from clumping together. Source

Future Implications

These findings contribute to the development of safer and more effective cancer treatments. By controlling drug release and targeting tumors specifically, the system has the potential to reduce side effects and improve patient quality of life. Source GNano continues to develop new nanostructured materials for advanced cancer diagnostics and therapies, as well as safer delivery systems for agricultural applications. Source

Further research will focus on exploring the potential of carbonated hydroxyapatite in environmental applications, such as photocatalysis, and in the development of luminescent scaffolds for tissue engineering. Source

Further Reading:

• Agência FAPESP – Researchers make breakthrough in biomedical imaging and cancer treatment
• Phys.org – Engineered nanoparticles display enhanced intrinsic luminescence for biomedical imaging and cancer treatment
• Bioengineer.org – Scientists Achieve Major Breakthrough in Biomedical Imaging and Cancer Therapy
• GNano – Laboratory of Nanomedicine and Nanotoxicology