Seminar of the cluster of the laboratories of Nano-Bioengineering and Hybrid Photonic Nanomaterials of NRNU MEPhI: Nanomedicine and diagnosis of malignant tumors

The use of nanotechnologies for developing more efficient approaches to the diagnosis and cure of socially important diseases is a key R&D area of the cluster of international laboratories of Nano-Bioengineering (LNBE) and Hybrid Photonic Nanomaterials (LPNM) of NRNU MEPhI.

Researchers of the Nanomedicine Group of LNBE presented two lines of research in this field at a seminar held on March 27: development of polymer microcapsule carriers for targeted delivery of antitumor drugs and diagnostic probes employing the effect of the nonradiative Förster Resonance Energy Transfer (FRET).

Galina Nifontova, Ph.D., senior researcher, presented the results of the project on Multifunctional Stimulus-Sensitive Microcapsules and Nanocrystals for Early Diagnosis and Efficacious Treatment of Lung and Breast Cancers, which is carried out in the framework of the State Contract for research at NRNU MEPhI. The polymer microcapsules designed in this project can be used for both detection of cancer cells and targeted delivery of drugs. For this purpose, the surface of the microcapsules is rendered specific for interaction with biomarker of malignant tumors by binding capture molecules (antibodies) to it, and the polyelectrolyte polymer shells of the microcapsules are embedded with semiconductor quantum dots serving as fluorescent labels, magnetic nanoparticles ensuring the delivery of the microcapsules to the target site using a magnetic field, and plasmonic (metal) nanoparticles allowing the microcapsule contents to be released through local heating and destruction of the shell caused by an external alternate electromagnetic field.

The results presented at the seminar were recently published in two top-rated international journals,

- Frontiers in Chemistry (Nifontova et al., Cancer cell targeting with functionalized quantum dot–encoded polyelectrolyte microcapsules) and

- Nanoscale Research Letters (Nifontova et al., Bioimaging tools based on polyelectrolyte microcapsules encoded with fluorescent semiconductor nanoparticles: Design and characterization of the fluorescent properties),

and reported as oral presentations at a number of prestigious international conferences.

Irina Petrova, Ph.D., researcher, presented a report entitled FRET Sensing and Surface Modes in Photonic Crystals. This line of research employs the effect of the nonradiative FRET for detecting biological objects, in particular, cells carrying disease markers, in liquid probes. If energy is nonradiatively transferred from the fluorophore absorbing light (donor), its fluorescence is quenched, while the fluorescence of the other fluorophore (acceptor, whose absorption spectrum overlaps with the fluorescence spectrum of the donor) is enhanced. It is important that FRET is only expressed when the distance between the donor and the acceptor is less than 100 nm, its rate being inversely proportional to the sixth power of the donor-to-acceptor distance.

These properties of FRET are used in DIOR, a joint project of LNBE and the International Center for Nanophotonics and Metamaterials of ITMO University. In one of developments, a quantum dot serves as the donor, and AlexaFluor organic dye, as the acceptor. They are bound with antibodies recognizing different epitopes (sites) of the same cancer marker molecule. Thus, if a tested sample contains the cancer marker, and the antibodies bound with the donor and acceptor interact with it, the two fluorophores get close to each other enough for effective energy transfer from the donor to the acceptor, and the cancer marker can be detected via observation of FRET.

 

Detection of surface modes in photonic crystals is another novel approach to the detection of biomolecules and diagnosis. It is based on the excitation of an optical wave in a substrate representing a one-dimensional photonic crystal capable of sustaining the propagation of a surface optical wave upon laser irradiation. Mass transfer (interactions) on the photonic crystal surface causes changes in the surface wave propagation, which lead to changes in the reflection angle of the laser beam. Thus, if we "tether" the molecules recognizing the disease markers to the photonic crystal surface, their interaction with the respective targets will make it possible to detect this interaction instantly, in the flow-through mode.

Experiments have shown that this method allows simultaneous detection of three biomarkers in a solution with a picogram sensitivity using a multichannel flow cell.

There are grounds to believe that implementation of these approaches to medical practice will lift cancer diagnosis and treatment to a new plane.

Contacts:

Galina O. Nifontova, Ph.D., senior researcher (galya.nif@yandex.ru, nifontovago@gmail.com)

Irina O. Petrova, Ph.D., researcher (iopetrova17@gmail.com)

Maria G. Korenkova, director of external relations (MGKorenkova@mephi.ru)

Laboratory of Nano-Bioengineering, Moscow Engineering Physics Institute
31 Kashirskoe shosse, 115409 Moscow, Russian Federation
http://www.lnbe.mephi.ru/en

 
 
 
© 2012 Laboratory of Nano-BioEngineering