Nanoparticle Development for Bioimaging
Researchers at the University of São Paulo's São Carlos Institute of Physics (IFSC-USP) in Brazil have developed a method to transform hydroxyapatite, a bioceramic material, into a nanoparticle with enhanced intrinsic luminescence. This innovation is intended for use in biocompatible, low-cost nanomaterials for biomedical imaging techniques.
This enhancement was achieved by incorporating carbonate groups into the hydroxyapatite structure, which increases the concentration of crystal defects responsible for the material's increased luminescence.
After functionalization with citrate to improve colloidal stability in aqueous media, these calcium phosphate nanoparticles can serve as luminescent agents for cellular bioimaging.
The bioimaging capability was demonstrated through visualization of nanoparticle internalization into cells using confocal fluorescence microscopy, relying solely on their intrinsic luminescence. Cellular internalization was further confirmed by flow cytometry, and biocompatibility was assessed via cellular cytotoxicity assays.
This study, led by Professor Valtencir Zucolotto and published in ACS Nanoscience Au, also provides a foundation for developing hydroxyapatite-based photocatalytic materials and for spectroscopic studies of hard tissues.
Targeted Cancer Treatment with Nanoparticles
In a separate study, the Nanomedicine and Nanotoxicology Group (GNano) and the Center for Molecular Engineering of Advanced Materials (CEMol) developed a strategy for delivering gemcitabine, a chemotherapy drug, using calcium phosphate nanoparticles.
This system is designed to be dual pH-responsive, keeping the drug inactive in normal physiological conditions, such as the bloodstream, and releasing it in its active form specifically in the more acidic environments characteristic of tumor regions.
This aims to improve bioavailability and therapeutic potential.
The research also involved functionalizing the nanoparticle surface with folic acid via stable covalent bonds. Folic acid acts as a targeting molecule due to many tumor cells exhibiting a higher demand for this vitamin.
This combination of controlled release and active targeting aims to achieve higher drug concentrations in tested tumor cells, including those from breast and cervical cancer, potentially reducing unwanted side effects in healthy tissues.
This system, published in ACS Applied Bio Materials, involved the development of a prodrug where gemcitabine was linked to carboxymethylcellulose. This linkage protects the drug from premature degradation and ensures its release specifically in acidic environments. The use of calcium phosphate, a naturally biocompatible material, enhances the safety of the strategy.
Researchers indicate that such systems could lead to more efficient chemotherapy with lower doses and reduced damage to healthy tissues, potentially improving patient quality of life.