Multifunctional Rare Earth-Based Biophotonic Composites

Image showing use of bio-encapsulated Rare Earth (RE) doped nanoparticles targeting melanoma cells.


Invention Summary:

Researchers at Rutgers University have developed new rare earth (RE)-based light-emitting, multifunctional composites for use in various biomedical applications, such as non-invasive imaging, image–guided interventions, drug tracking and delivery, and photodynamic therapy applications. They found that the properties of the composites, in particular their aqueous stability, solubility, biocompatibility, and functionality, can be tailored for such applications by coating RE nanoparticles with suitable polypeptides, polysaccharides or polymers. The resulting composites can be of various size (e.g., on the order of nanometers or micrometers) and morphology (e.g. spheres, rods, and platelets). They can also be further modified by conjugation with various compounds, e.g., with antibodies for imaging applications or with therapeutic agents for drug delivery applications. For example, composites for use as contrast agents have been prepared by coating RE nanoparticles with human serum Albumin Nanoshells ((RE) ANS) and functionalizing them with arginine-glycine-aspartic acid (cRGD) tripeptide, an antagonist of integrin αvβ3, to identify cancer cells overexpressing integrin αvβ3. These composites were shown to be capable of selectively targeting human glioblastoma and melanoma cells overexpressing integrin αvβ3.

The RE-doped nanoparticles can be tuned to emit light in the visible region of the spectrum (400-700nm), or in the shortwave IR region (1000-2500nm), with excitation at near IR wavelengths (700-1000nm). Meanwhile, the bio-coated RE nanoparticles maintain their inherent IR-emission properties, which allow for deeper tissue penetration and low background tissue autofluorescence. Encapsulation in the form of ((RE) ANS) attenuated RE-induced cytotoxicity and significantly improved their biocompatibility. Using IR-emission contrast agents over traditional organic dye methods can increase the imaging sensitivity up to 10x and decrease the loss in emission intensities over time. Also, the RE nanoparticles can be optimally excited at a narrower emission bandwidth and at a much lower power than carbon nanotubes or gold particles. 

Market Applications:

  • Non-invasive imaging (2-dimensional and 3-dimensional)
  • Image-guided interventions (surgical and non-surgical)
  • Drug tracking and delivery
  • Photodynamic therapy

Advantages:

  • Eliminates harmful side effects of high-energy radiation sources
  • Increased sensitivity and stability over organic dyes
  • Wavelengths of emissions can be tailored by controlling the nature and concentration of the dopant and host molecules
  • Infrared excitation enables deeper tissue penetration depths with low background tissue autofluorescence
  • No overlap between the excitation and emission wavelengths, images with high signal-to-noise ratio can be collected
  • Can be used as a medical monitoring method
  • Multi-functionality as contrast agent/probe/drug carrier

Intellectual Property & Development Status:

Patent pending. In vitro human melanoma/glioblastoma cell and in vivo murine melanoma data is available.Available for licensing and/or research collaborations.