NEWS OF THE W EEK
SEARCH FOR AIDS VACCINE RAMPS UP RESEARCH: New York City lab opens
amid challenges for AIDS vaccines
T
design and development of an AIDS vaccine opened for business last week. The ribbon cutting at the Brooklyn, N.Y.-based research center coincided with news that yet another drug company has abandoned its AIDS vaccine efforts. The AIDS Vaccine Design & Development Laboratory will pursue three main goals, says Wayne Koff, senior vice president of R&D for the International AIDS Vaccine Initiative (IAVI), the global public-private partnership that opened the lab. First, it wants to design a vaccine that will prompt the immune system to make antibodies that can neutralize multiple strains of the AIDS virus. Second, it wants to find vaccine candidates against existing HIV infections. And third, it wants N EWSCO M
IAVI researchers at SUNY Downstate (pictured) have been relocated to new facility.
HE WORLD’S ONLY lab solely dedicated to the
TINY BACKPACKS FOR CELLS NANOTECHNOLOGY: Polymer patches add cargo to cells without disturbing normal activities
© 20 0 8 N A N O L ET T.
Confocal microscopy reveals an immune cell equipped with a fluorophore-filled nanobackpack.
C
ELLS CAN NOW accessorize with the latest in
multilayered polymer patches without fear of cramping their style. The patches attach to immune cell surfaces like backpacks on schoolchildren, and they don’t interfere with regular cell functions (Nano Lett., DOI: 10.1021/nl802404h). The nanobackpacks could one day turn cells into drug delivery vehicles. Several teams have tried to give cells new functions, including drug delivery, by encasing them in polymer shells that can be derivatized. But polymer encasement isn’t universally applicable because “many cells need to interact with their surroundings to do their jobs,” says MIT materials scientist Michael F. Rubner. Rubner teamed up with MIT engineers Darrell J. Irvine and Robert E. Cohen to figure out how to functionalize immune cells, which need their surfaces to communicate properly. WWW.C E N- ONLI NE .ORG
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to move vaccine candidates from the lab to the clinic as quickly as possible. This means assisting in process development, designing better adjuvants and delivery systems, and prioritizing candidates, Koff explains. Scientists at the facility are also devoted to maintaining an open flow of ideas between IAVI and its partners around the world. They expect to run training courses and actively transfer technology to IAVI’s partners, while also exchanging faculty and scientists. The opening of the lab comes amid turbulent times for the AIDS vaccine community. Last year, Merck & Co. halted a large, midstage trial comparing its recombinant adenovirus 5 vector vaccine to a placebo. Not only did the vaccine prove ineffective, but Merck also reported an alarming uptick in new HIV infections among patients given the vaccine. Then last week, Wyeth announced that it would jettison its AIDS vaccine efforts by selling its viral vaccine portfolio to Profectus Biosciences. The Merck failure “was probably the last nail in the coffin” for big pharma’s interest in the field, says IAVI CEO Seth Berkley. Merck had been the only big drug company funding a major AIDS vaccine program with shareholder money. Other firms had turned to government and private sources to bankroll their efforts. But Berkley is confident that drug company interest will return if a promising vaccine candidate emerges from a biotech company, IAVI’s new labs, or elsewhere in the public sector.—LISA JARVIS
They settled on three-layer polymer patches that cover only part of cells’ surfaces. MIT graduate student Albert J. Swiston built the patches, which contain a customizable cargo layer sandwiched between a hyaluronic acid-based layer for attachment to immune cells and a layer that tethers the patch to a glass surface. After assembly, he delivered cells to the patches with a pipette. A temperature change dissolved the tethering layer, leaving free-floating cells with exposed cargo. The team demonstrated the approach by using patches loaded with magnetic nanoparticles to control the movement of mouse immune cells by applying a magnetic field. The study is “a step toward exploiting the power and potential of layer-by-layer assembly in biomedical applications,” says Mike McShane, an expert in materials patterning at Texas A&M University. “Living cells don’t particularly like to have external, synthetic entities attached to them,” says Raz Jelinek, a membrane biophysicist at Ben-Gurion University of the Negev, in Israel. The MIT team’s elegant work circumvents that problem, but they still must determine whether the patches elicit immune reactions, he says. The work is at an early stage and animal testing has yet to take place, Rubner says. But because the cargoladen polymer patches are made before any cells enter the picture, polymerization and derivatization chemistries do not affect cells directly and therefore can quickly be adapted, he adds.—CARMEN DRAHL
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