Researchers at the University of British Columbia have identified a small molecule that prevents bacteria from forming into biofilms, a frequent cause of infections. The anti-biofilm peptide works on a range of bacteria including many that cannot be treated by antibiotics.

‘Currently there is a severe problem with antibiotic-resistant organisms,’ says Bob Hancock, a professor in UBC

By discovering a new mechanism that allows blood to enter the brain immediately after a stroke, researchers at UC Irvine and the Salk Institute have opened the door to new therapies that may limit or prevent stroke-induced brain damage.

A complex and devastating neurological condition, stroke is the fourth-leading cause of death and primary reason for disability in the U.S. The blood-brain barrier is severely damaged in a stroke and lets blood-borne material into the brain, causing the permanent deficits in movement and cognition seen in stroke patients.

Dritan Agalliu, assistant professor of developmental & cell biology at UC Irvine, and Axel Nimmerjahn of the Salk Institute for Biological Studies developed a novel transgenic mouse strain in which they use a fluorescent tag to see the tight, barrier-forming junctions between the cells that make up blood vessels in the central nervous system. This allows them to perceive dynamic changes in the barrier during and after strokes in living animals.

While observing that barrier function is rapidly impaired after a stroke (within six hours), they unexpectedly found that this early barrier failure is not due to the breakdown of tight junctions between blood vessel cells, as had previously been suspected. In fact, junction deterioration did not occur until two days after the event.

Instead, the scientists reported dramatic increases in carrier proteins called serum albumin flowing directly into brain tissue. These proteins travel through the cells composing blood vessels

When a person suffers a broken bone, treatment calls for the surgeon to insert screws and plates to help bond the broken sections and enable the fracture to heal. These ‘fixation devices’ are usually made of metal alloys.

But metal devices may have disadvantages: Because they are stiff and unyielding, they can cause stress to underlying bone. They also pose an increased risk of infection and poor wound healing. In some cases, the metal implants must be removed following fracture healing, necessitating a second surgery. Resorbable fixation devices, made of synthetic polymers, avoid some of these problems but may pose a risk of inflammatory reactions and are difficult to implant.

Now, using pure silk protein derived from silkworm cocoons, a team of investigators from Tufts University School of Engineering and Beth Israel Deaconess Medical Center (BIDMC) has developed surgical plates and screws that may not only offer improved bone remodelling following injury, but importantly, can also be absorbed by the body over time, eliminating the need for surgical removal of the devices.
‘Unlike metal, the composition of silk protein may be similar to bone composition,’ says co-senior author Samuel Lin, MD, of the Division of Plastic and Reconstructive Surgery at BIDMC and Associate Professor of Surgery at Harvard Medical School. ‘Silk materials are extremely robust. They maintain structural stability under very high temperatures and withstand other extreme conditions, and they can be readily sterilised.’

Collaborating with Lin were co-senior author and Tufts chair of biomedical engineering David Kaplan, PhD, a leader in the use of silk for biomedical applications, and a team of biomedical and mechanical engineers.

‘One of the other big advantages of silk is that it can stabilise and deliver bioactive components, so that plates and screws made of silk could actually deliver antibiotics to prevent infection, pharmaceuticals to enhance bone regrowth and other therapeutics to support healing,’ says Kaplan.

Kaplan and his team have previously developed silk-based sponges, fibres and foams for use in the operating room and in clinical settings. But until now, silk hadn

New research identifies a new type of light sensor that could allow medical and security imaging, via low cost cameras. The team of researchers from the University of Surrey have developed a new