21^st European Biotechnology Congress

There are already some means to deliver drugs inside cells bypassing the lysosomal degradation. Thus, coupling of cellpenetrating

peptides (CPP) to various molecules, including peptides and proteins, or even to nanoparticles, such as

liposomes, dramatically facilitates their intracellular delivery. Similar effect could be achieved using phage coat fusion proteins

purified from the phages selected for their specificity towards certain target cells as was shown with liposome-loaded anticancer

drugs. The combination of targeted delivery of drug-loaded nanopreparations to target cells and their subsequent delivery

inside cells might still further improve the efficiency of therapy. Intracellular drug delivery with subsequent organelle targeting

opens new opportunities in overcoming problems associated with multiple pathologies including lysosomal storage diseases

and multidrug resistance (MDR) tumors. Delivery of deficient enzymes for the treatment of lysosomal diseases evidently

requires specific targeting of lysosomes, while facilitating apoptotic cell death in MDR tumor would require targeting of

mitochondria or lysosomes. Thus, next generation drug delivery systems should be able to target individual organelles inside

cells. Clearly, this challenge will require some novel approaches in engineering multifunctional nanomedicines, capable of

accumulating in the target tissue, penetrating inside cells, bypassing lysosomes, and bringing pharmaceuticals to individual

organelles. Examples of specific targeting of pharmaceutical nanocarriers loaded with pharmaceutical agents to lysosomes and

mitochondria in cells illustrate the benefits of this new approach.