Assembly and Characterization of Nano-Complexes: Quantum Dot Encapsulated Liposomes

Idan Mandelbaum and Angela R. Hight Walker

Optical Technology Division, Physics Laboratory

Liposome complexes have received significant attention for a variety of biochemical and biomedical applications including drug targeting and drug delivery and tumor imaging and diagnostics.  Semiconductor nano-crystals, also known as quantum dots, are now beginning to be used in similar biochemical experiments.  Like fluorescent dyes, these quantum dots have the ability to reliably fluoresce at pre-engineered wavelengths.  However, these nano-crystal have lifetimes significantly longer comparable to fluorescence dye counterparts.  We have successfully encapsulated approximately 10nm CdSe nano-crystals inside approximately 100nm liposomes and studies the resulting complex using fluorescence resonance energy transfer microscopy (FRETM.)  Further studies were performed using transmission electron microscopy showing the details of the encapsulation.  Our nano-manufactured quantum dot liposome complexes do not bleach over periods of hours and are general enough to allow the addition of drugs targeted for the vectored cells thus offering the ability to both image and medicate simultaneously over a long period of time.

Idan Mandelbaum

Optical Technology Division (844.06)
Laser Applications
Building 216, Room 225B

100 Bureau Drive,  MS8443
Gaithersburg, MD 20899-8443
T: (301) 975-8241
F: (301) 975-6991
idan.mandelbaum@nist.gov

Member of Sigma Xi

Mentor: Angela R. Hight Walker

Category: Biotechnology