Posts Tagged ‘drug delivery vehicles’

Self-propelled Liposomes as a Drug Delivery System

Reporter: Irina Robu, PhD

Liposomes are small artificial vesicles of spherical shape that can be created from cholesterol and natural non-toxic phospholipids. As a result of their size and hydrophobic and hydrophilic character, liposomes are promising systems for drug delivery. Liposome properties diverge considerably with lipid composition, surface charge, size, and the method of preparation. Scientists at Penn State developed self-propelled liposomes that migrate away and/or towards chemical signals, making it possible for self-directed drug delivery vehicles that can actively target a specific area of the body. Besides, the choice of bilayer components controls the ‘rigidity’ or ‘fluidity’ and the charge of the bilayer. Countless liposomes proposed for drug delivery are tissue-specific, since of antibodies on their surface bind to the target tissue when they encounter it. The technology may help to enhance efficacy and reduce side-effects of drugs in a variation of applications.

Yet, the key to drug delivery is enhancing the specificity and affinity of a drug delivery vehicle for its target tissue. As the drawbacks of conventional drug therapies, scientists are developing an extensive variability of drug delivery vehicles including nanoparticles, biomaterials, and implantable devices, to increase drug accumulation at a target site in the body and reduce side-effects elsewhere. To address the drawbacks, these researchers developed a type of liposome that can actively propel itself near a chemical signal in the body, such as a chemical attractant released by a target tissue.

The liposomes proposed by Penn researchers are covered in enzymes that react with specific substrates to produce energy, which can help to push the liposomes along, through a phenomenon called chemotaxis. By changing the enzymes coating the liposomes, the investigators can tune this chemotaxis and permit the particles to either move towards or away the chemical signal. This could aid the particles to gravitate near certain tissues, and possibly avoid others in the body.
Currently, the are still developing the liposomes, and hope that they will be able to use them for drug delivery soon

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