Jul 31 2014
Intracerebral hemorrhage is a type of stroke that affects two million people worldwide each year. Despite its seriousness, no effective treatment has yet been developed. But if a recent study in the journal Nanomedicine is right, good news for doctors and patients might one day arrive in a very small package: namely, a “peptide nanofiber scaffold.”
In the last few decades, molecular engineering of various self-assembling peptide nanofiber scaffolds (SAPNS) has emerged as an active area of research. The peptide can form stable structures that self-assemble into a gel-like substance.
Now a University of Hong Kong team led by Professor Raymond Tak Fai Cheung, PhD and his student Lynn Yan-Hua Sang, PhD, who performed the majority of the experimental work, suggests a new therapeutic strategy for intracerebral hemorrhage: injecting SAPNS directly into a hemorrhagic lesion. Using rats, the team found that SAPNS attenuated brain injury, reduced brain cavity volume and enhanced recovery of brain function. This is the first time a nanomaterial has been used to replace the hematoma in the deep brain in a rat model of intracerebral hemorrhage. The hemostatic effects of SAPNS and other self-assembling peptides were discovered by co-author Rutledge G. Ellis-Behnke, PhD, who advised Drs. Cheung and Sang.
One man with a keen interest in this result is Terrence W. Norchi, President and CEO of Arch Therapeutics, a Wellesley, MA-based medical device company that is exploring a potential alternative approach to traditional stasis and barrier applications, including stopping bleeding during surgery, after trauma and other applications. Arch Therapeutics is also the worldwide exclusive licensee of intellectual property owned by the Massachusetts Institute of Technology (MIT) and the University of Hong Kong (UHK), in which the composition of SAPNS is a cited agent for stopping bleeding. Dr. Ellis-Behnke, who performed his groundbreaking hemostasis research at MIT and UHK, is a co-founder of Arch Therapeutics.
Arch’s AC5 Surgical Hemostatic Device™, currently in preclinical development, is also a peptide nanofiber scaffold—one that is being designed to achieve hemostasis in laparoscopic and open surgical procedures. It represents a new approach to the rapid cessation of bleeding and control of fluid leakage during surgery and trauma care. The time to hemostasis with this approach is measured typically in 15 to 30 seconds rather than several minutes as with existing solutions. It is also being designed to conform to irregular wound geometry, to allow for normal healing and to help maintain a clear field of vision in the wound area during the surgical procedure.
Because it is transparent and neither sticky nor glue-like, evidence supports that AC5 can be used in the laparoscopic or minimally invasive surgical setting. It consists of a synthetic peptide comprising naturally occurring amino acids that are not sourced from animals. When squirted or sprayed onto a wound, the clear, transparent liquid promptly intercalates into the nooks and crannies of the connective tissue where it self-assembles itself into a lattice-like gel—a physical structure that provides a barrier to leaking substances. It is being designed to quickly stop bleeding with rapid onset of hemostasis, and might also allow surgeons to safely operate through the resulting protective barrier. During the healing process, data supports that the underlying peptide is broken down into its constituent amino acids, then absorbed and either used in the amino acid pool of the body to build protein and muscle, or excreted in the urine.
Advances such as these point toward a future in which self-assembling peptides are a key tool for addressing some of the challenges faced by surgeons today.