We all know about oil and water: They don’t mix.

Phos­pho­lipids, how­ever, are the two-​​sided excep­tion that proves this rule. One side of a phos­pho­lipid mol­e­cule loves to hang out in water, while the other turns away from it like the most timid housecat.

In the mid-​​1960s, Dr. Alec Bangham dis­cov­ered that when dis­persed in water, phos­pho­lipids aggre­gate into closed, spher­ical vesi­cles called lipo­somes. The water-​​loving sides form a pro­tec­tive bar­rier around their oily neigh­bors in what’s called a lipid bilayer (the mem­branes that sur­round our cells are made of the same stuff).

You cannot list too many sys­tems with such a nice set of prop­er­ties,” said Vladimir Torchilin, a Uni­ver­sity Dis­tin­guished Pro­fessor at North­eastern Uni­ver­sity, who recently received the Bangham Award for his out­standing con­tri­bu­tions to the study of liposomes.

They are easy to make and easy to scale up,” he added. “You can pretty easily load them with many types of drugs. They are com­pletely bio­com­pat­ible. And they are stable enough to exist for a few hours in the body.”

For these rea­sons, Torchilin and his col­leagues quickly real­ized that lipo­somes would make great car­riers for tar­geted drug delivery. By the late-​​1970s they demon­strated that these con­ve­nient cre­ations could be func­tion­al­ized with pro­teins that dis­crim­i­nately home to spe­cific cell types, such as car­diac or cancer cells. Like micro­scopic “pas­senger trains,” Torchilin explained, lipo­somes could be designed to trans­port drugs to a desired final destination.

Today, Torchilin’s research focuses on cancer drug delivery. Instead of pas­senger trains, the lipo­somes act like Trojan Horses, deliv­ering the toxic effects of chemother­a­pies directly to the cells we want to destroy. Because this approach brings a higher con­cen­tra­tion of drug directly to the tumor, Torchilin explained, it “allows you to decrease the total dose you admin­ister, which in turn reduces the level of cyto­toxic response from normal tissue.”

The first lipo­somal drugs, which were approved in the mid-​​1990s, focus on a char­ac­ter­istic of the vas­cu­la­ture that sup­plies tumors. “Tumor blood ves­sels are leaky,” said Torchilin. “And the par­ti­cles fall through the blood ves­sels into the tumor tissue.” But, he explained, this still leaves room for the drug to get acci­den­tally directed to healthy tissue.

Torchilin and his col­leagues are cur­rently devel­oping plat­forms that induce cancer cells to directly inter­nalize lipo­somes. When the vesi­cles break down, their con­tents are released exclu­sively inside the cell. While it’s still not fool­proof, this kind of active tar­geting allows clin­i­cians to deliver much more effec­tive treatments.

The drug dox­oru­bicin, for example, has been used for nearly half a cen­tury. But it is highly toxic to many cell types including heart cells. Car­diac dis­ease — a dev­as­tating dis­ease in its own right — is a side effect of the drug. But once inside a lipo­some, dox­oru­bicin comes into con­tact with healthy cells much less fre­quently. This also allows for higher dosages, which in turn improves the drug’s already good effectiveness.

Overall, Torchilin said, “the goal of the lab is to save lives from time to time.” Cancer is a highly nuanced dis­ease and tar­geted drug delivery is still not per­fect, says Torchilin, but in the last sev­eral decades it has come quite a long way. He’s con­fi­dent his inno­va­tions will con­tinue to improve delivery platforms.

Dr. Torchilin will present a lec­ture on his accom­plish­ments in the area of lipo­some research at the Lipo­some Research Days meeting in Hangzhou China on October 12, 2012.