Srinivas Dinakar’s presentation

NANOERTHYROSOMES as NOVEL DRUG CARRIERS

CO-ORDINATOR : Mrs.Pavani ,M.PharmCO-AUTHOR : Nikhil Reddy .Y

DEFINITION

Nanoerythrosomes are erythrocytes based new drug carrier which is prepared by extrusion of erythrocyte ghosts to produce small vesicles having an average diameter of 100nm

RESEALED ERYTHROCYTES

When erythrocytes are suspended in a hypnotic medium they swell about one and half times their original size and membrane ruptures resulting in the formation of pores with diameter of 200-500Å0

If the ionic strength of the medium is adjusted to isotonicity and the cells are incubated at 37˚and causes the erythrocytes to reseal.

ISOLATION OF ERYTHROCYTES

Blood is collected in to heparinized tubes by vein puncture .

Blood is with drawn from cardiac or splenic puncture (small animals ) and through veins (large animals) in a syringe containing a drop of anti coagulant .

The whole blood is centrifuged at 2500rpm for 5 min at 3-5˚c in refrigerated centrifuge.

Serum and buffy coats are carefully removed and packed cells are washed with PBS.

The washed erythrocytes are diluted with PBS and stored at 4˚c until used.

ERYTHROCYTES GHOST

RBC’s on haemolysis and washing with large volume of hypnotic medium, loose nearly all their hemoglobin and on releasing the resultant cells appear as pale or transparent in appearance and are referred as erythrocytes ghost

Preparation and loading of nanoerythrosomes :

Methods employed are:Extrusion Sonication Electrical break down method

Normal erythrocytes

Preparation of erythrocyte ghosts

extrusion/ Sonication /electrical break down method

Nano vesicles staining with 0.1% uranyl acetate and microscopical examination

Nanoerythrosomes

EXTRUSION

Erythrocytes ghosts suspension was extruded through polycarbonate membrane filter which was connected to an adapter

Nanoerythrocytes were obtained by 8 consecutive extrusions

Extrusion was done using nitrogen pressure

SONICATION

Erythrocytes ghosts suspension was sonicated at an energy level of 50W for 5 min using dismembrator.

ELECTRIC BREAK DOWN

Erythrocyte ghost suspension was subjected to variable electric voltage for 100 µseconds.

Temperature maintained at 37˚c

In extrusion and Sonication the final preparation was stored at 3-5 ˚c in refrigerator

DRUG NANOERYTHROSOME CONJUGATION

Methotrexate was conjugated to nanoerythrosomes membrane using glyceraldehydes as cross linker.

The complex was washed with PBS and stored at 3-5˚c

Entrapment efficiency

Amount of drug loaded x 100Amount of drug added

IN VITRO CHARACTERIZATION

SCANNING ELECTRON MICROSCOPY OF nEs• EG’s (2parts) + saline buffer (25 parts)

Formulation is dehydrated and dried to critical point

• One drop of the diluted mixture is placed on a silver coated copper grid ,then coated with gold

TRANSMISSION ELECTRON MICROSCOPY OF nEs

• EG’s (2parts) + saline buffer(25parts)

• One drop of the diluted mixture is placed on a coated copper grid and negatively stained with 1% uranyl acetate Then the drop of mixture is seen through a transmission electron microscope.

ROUTE OF ADMINISTRATION

They can be administered intravenously or intra arterially.

APPLICATIONS

They can target the drugs with in reticulo endothelial system.

Carriers for drugs , proteins , enzymes ,macromolecules.

Treatment of liver tumors, parasitic diseases, enzyme deficiency.

FUTURE PERSPECTIVES

A large amount of valuable work is needed so as to utilize the potentials of nanoerythrosomes

Disease like cancer could surely find its cure with the help of nanoerythrosomes.

Genetic engineering aspects can be coupled to give newer dimension to the existing drug carrier concept.

CONCLUSION

‘GOLDEN EGGS IN NOVEL DRUG DELIVERY SYSTEM’ considering their tremendous potential

REFERENCES-Advances in controlled and novel drug delivery ,edited by N.K JAIN ,CBS publishers.pg.no 332-351-Anatomy and Physiology-Ross and Wilson’s Human Anatomy and Physiology