Research Group

Researchers
Dr A. Xenakis, Researcher Director (Program Head)

Post-Doc Collaborating Researchers
Dr. Haris Stamatis, Chemist
Dr. Spyros Avramiotis, Chemist
Dr. Vassiliki Papadimitriou, Chemist

PhD Students
Mrs. Maria Zoubanioti, Chem. Eng.
Mr. Evangelos Caravas, Chemist

Msc. Students
Evangelia Tzika, Chemist
Thodoros Karandreas, Chemist
Paris Parmaklis Chem. Eng.

Technicians
Mrs. Maria Roubi
Mrs. Stathis Kaldanis

Aims of the Programme

The Biomimetics and Nanobiotechnology Programme deals with studies on the behavior of biomolecules, such as enzymes, in model systems simulating their natural environment. The studies are focused on structural and functional aspects of the biomolecules when hosted in environments with restricted water contents, such as microemulsions.
Water-in-oil microemulsions are fine dispersions of water in an organic non-polar solvent (oil) stabilized by one monolayer of surfactant molecules. These systems allow the simultaneous solubilization of compounds with different polarities, such as lipophilic ones located in the continuous organic phase, or hydrophilic ones enclosed in the dispersed aqueous phase, which can react through an enormous interface. It is, thus, possible to encapsulate enzymes and to use them as catalysts in reactions of substrates non soluble in water. Microemulsions can also be used to study membrane enzymes, as well as media for the protection of enzymes against denaturation.

Four main activities are developed within the Biomimetics programme:

• Structure and function studies of enzymes in microemulsions
• Structural studies of microemulsions, using spectroscopic techniques
• Development of novel nanobiotechnological applications
• Biotechnological applications of olive oil
  
  These studies have yielded various applications, which are developed within the Industrial Enzymology Unit of IBRB, in collaboration with Food, Pharmaceutics, and Cosmetics industries.

Current Externally Funded projects:

1. Program ΕΠΑΝ ''Supporting research groups for exploiting research results. Finding and valorizating results through spin off company creation. PhaseΑ'. Preparation of the investment'' (2002-4) Κωδ. 01 ΠΡΑΞΕ 18. Budget: 44.000,00 €

2. Program IKYDA (2002-5) ''Enzyme immobilization in microemulsion organogels - Study in supercritical fluids''. Collaboration με Prof. Werner Kuntz Institute of Physical and Theoretical Chemistry, Regensburg University, Regensburg, Germany Budget 15.000,00€

3. Program ''ΣΥΝΕΡΓΑΣΙΑ'' of the Dir.1334/02 - ELAIOURGIKI - ΟΠΕΚΕΠΕ (2003-4) "Determination of the most significant and usual quality problems encountered in greek olive oils. Evaluation and therapeutic actions" Budget 23.600,00 €

Collaboration with the research groups of:
a. ELAIOURGIKI SA.
b. Assos.Prof.M.Tsimidou, Food Chem. & Technol. Lab., Univ. of Thessaloniki
c. As.Prof.Ε.Psomiadou, Food Chem lab., Chemistry dept., Univ.of Ioannina

4. Program ''Cretan Collaboration'' of the Dir.1334/02 - ΟΠΕΚΕΠΕ - Agr.Unions of Siteia, Peza, Mylopotmos, Mirambello (2004-5) ''Study of the parameters related to the quality of virgin olive oil; effect of the maturity degree on the natural antioxidant content.'' Budget 29.759,52 €

Collaboration with the research group of Prof. Ν.Haniotakis, Chemistry dept., Univ.of Crete

Complete list of programs

Collaborations with Industries

Collaboration with Food Industries

ΓΙΩΤΗΣ Α.Ε.
-Submission ΕΠΕΤ ΙΙ ΕΚΒΑΝ "Effect of high pressure on biological substances and application to the food industry"

UNILEVER
- Common Program BIOTECH of the EU (1994-1996) "Structure-function lipase relationships in low water media".

Collaboration with Chemical Industries

MERCK
- Common Program BRIDGE of the European Community Commission (1991-94) New ways of Biotransformation in non-aqueous systems for the synthesis of pharmaceuticals. Application of supercritical gases, organic solvents, liquid membranes and microemulsions

Collaboration with Pharmaceutical Industries

MEDICON AE
- Common Program ΥΠΕΡ "Development of a new enzymatic immunoassay for the production of clinical laboratory kits"
- Submission ΕΠΕΤ ΙΙ ΕΚΒΑΝ- 97

PHARMATHEN SA.
- Licensing of a Patent
- Common Program for the development of cosmetics
- Common Program ΠΑΒΕ "New technology for transdermal drug delivery. Application of microemulsions and organogels"
- Common Program ΠΑΒΕΤ "New systems for delivery of drugs and biologically active substances with repetitive and controlled release"

RESCO SA
- Submission ΠΕΝΕΔ 2003 "Development of nanodispersions of biologically or pharmaceutically active substances with antioxidant or anticancerogenic activity"

Selected Recent Publications

1.M. Zoumpanioti, M. Karali, A. Xenakis & H. Stamatis, (2005) ''Lipase biocatalytic processes in surfactant free microemulsion - like ternary systems and related organogels''. Enzym. Microb. Technol.. in press

2. V. Papadimitriou, T.G. Sotiroudis, and A. Xenakis (2005) ''Olive oil microemulsions as a biomimetic medium for enzymatic studies. Oxidation of oleuropein'' J.Am.Oil Chem. Soc. In press.

3. T.G. Sotiroudis, G.T. Sotiroudis, N. Varkas and A. Xenakis (2005) ''Interfacial properties of virgin olive oil-in-water emulsions stabilized by endogenous amphiphiles'' J.Am.Oil Chem. Soc. In press

4. P. Dominguez de Maria, H. Stamatis A. Xenakis J. V. Sinisterra (2004) ''Lipase Factor (LF) as a characterization parameter to explain the catalytic activity of crude lipases from Candida rugosa, ATCC 14830, free or immobilized in microemulsion based organogels'' Enzym. Microb. Technol.. 35, 277-283.

5. P. Dominguez de Maria, H. Stamatis A., Xenakis, J. V. Sinisterra (2004) ''Unexpected reaction profile observed in the synthesis of propyl laurate when using Candida rugosa lipases immobilized in microemulsions based organogels'' Biotechnol. Lett. 26: 1517-20.

6. M.Zoumpanioti, E.Karavas, C.Skopelitis, H.Stamatis, A. Xenakis. (2004) ''Lecithin organogels as model carriers of pharmaceuticals'' Progr. Colloid Polym. Sci., 123, 199-202.

7. E. Hatzara, E.Karatza, S. Avramiotis. A. Xenakis (2004) ''Spectroscopic mobility probing studies of lecithin organogels'' Progr. Colloid Polym. Sci., 123, 94-97

8. T.G. Sotiroudis, S.A. Kyrtopoulos, A. Xenakis, G.T. Sotiroudis (2003) ''Chemopreventive potential of minor components of olive oil against cancer'' Ital. J. Food Sci. 15, 169-185

9. C. Delimitsou, M. Zoumpanioti, A. Xenakis, H. Stamatis (2002) ''Activity and stability studies of mucor miehei lipase immobilized in novel microemulsion based organogels''. Biocatalysis and Biotransformations, 20, 319-327.S.Avramiotis,

10. D. Skoutas, D. Haralabopoulos, S. Avramiotis, T.G. Sotiroudis, A. Xenakis (2001) ''Virgin Olive Oil: Free Radical Production Studied with Spin Trapping EPR Spectroscopy'' J. Am. Oil Chem. Soc. 78, 1121-5.

Complete list of publications