Sutures have evolved with modern medicine though they have remained a passive part of the surgical and healing process till now. However, a new �smart� suture developed by a team of researchers at the University of Illinois at Urbana-Champaign have successfully developed an electronic suture that contains ultrathin silicon sensors integrated on polymer or silk strips and can be laced through the skin and knotted just like conventional medical stitches. These smart sutures are able to precisely measure body temperature at the site if the wound�infection elevates the skin's temperature�as well as to deliver heat to the wound site, which is known to aid in healing. With the help of his colleagues, John Rogers, a professor of materials science and engineering at the university, developed the suture using silicon membranes, gold electrodes, and wires that are just a few hundred nanometers thick and patterned in a serpentine shape. The researchers first use chemicals to slice off an ultrathin film of silicon from a silicon wafer. With a rubber stamp, they lift off and transfer the nanomembranes to polymer or silk strips. Then they deposit metal electrodes and wires on top and encapsulate the entire device in an epoxy coating. They have built two types of temperature sensors on the sutures. One is a silicon diode that shifts its current output with temperature; the other, a platinum nanomembrane resistor, changes its resistance with temperature. The micro-heaters, meanwhile, are simply gold filaments that heat up when current passes through them. All materials are said to be safe for use in the body; the sutures have been tested out by the researches on rat skin. The next step, they say, is to take this technology wireless. These new kinds of sutures provide at least two benefits, compared with conventional ones. First, the electronic stitches react to heat. Sensors attached to the sutures can report when the heat coming off a patient's wound is greater than expected, thereby indicating to doctors the presence of infection. This allows the patient to begin taking antibiotics much earlier than usual, preventing the infection from spreading and making it easier for doctors to eliminate it. The second benefit pertains to heat as well. The electronic sutures contain gold filaments that can heat up when attached to a power source. When a wound is exposed to an external heat source, the healing process is enhanced. Experts believe that having a controlled heat source in or near the wound should help the patient to a faster recovery. MC10, a Cambridge, Massachusetts-based startup company, is already working to commercialize the technology in the near future. However, for now electronic sutures are undergoing additional testing, and are not in everyday use.
Another new antibacterial coating for sutures could reduce infections after surgery. Scientists are reporting the discovery of a new coating that is almost 1,000 times more effective than the most widely used commercial coating. Their report appears in ACS' journal Langmuir. Professor Gregory Tew, who is from UMass-Amherst, and colleagues explain that infection at the site of surgical incisions is one of the most common post-surgical complications that keep patients hospitalized longer and boost hospital bills. The most common antibiotic coating contains triclosan, but its use in many consumer products over the years has led to the emergence of strains of bacteria that shrug off its effects. Triclosan also can be absorbed into the body, raising concerns about possible adverse health effects. Another downside to triclosan: It slows the growth of bacteria, but does not actually kill those already present. This made the scientists turned to PAMBM, a new substance designed from naturally occurring antimicrobial peptides that can kill a wide range of bacteria. And because of the way it works, PAMBM has a very low chance of causing bacterial resistance and the emergence of so-called superbugs. The report described laboratory tests in which PAMBM greatly reduced the amount of bacteria compared to triclosan. In a head-to-head test with triclosan-coated sutures, those coated with PAMBM were much more effective against bacteria.