New Bandage Could Seal Hole in the Heart

A Band-Aid® adhesive bandage is an effective treatment for stopping external bleeding from skin wounds, but an equally viable option for internal bleeding does not yet exist. Surgical glues are often used inside the body instead of traditional wound closure techniques like stitches, staples, and clips because they reduce the patient’s time in the hospital and lower the risk of secondary injury/damage at the wound site. An effective surgical glue needs to be strong, flexible, non-toxic, and able to accommodate movement, yet there are no adhesives currently available that have all of those properties. Researchers at the Wyss Institute (Harvard University) have developed a new super-strong hydrogel adhesive inspired by the glue secreted by a common slug that is biocompatible, flexible, and can stick to dynamically moving tissues even in the presence of blood.

The hydrogel itself is a hybrid of two different types of polymers: a seaweed extract called alginate that is used to thicken food, and polyacrylamide, which is the main material in soft contact lenses. When these relatively weak polymers become entangled with each other, they create a molecular network that demonstrates unprecedented toughness and resilience for hydrogel materials – on par with the body’s natural cartilage. When combined with an adhesive layer containing positively-charged polymer molecules (chitosan), the resulting hybrid material is able to bind to tissues stronger than any other available adhesive, stretch up to 20 times its initial length, and attach to wet tissue surfaces undergoing dynamic movement (e.g., a beating heart).

Studies of the hydrogel adhesive demonstrated that it is capable of withstanding three times the amount of tension that disrupts the best current medical adhesives, maintaining its stability and adhesion when implanted into rats for two weeks, and sealing a hole in a pig heart that was subjected to tens of thousands of cycles of pumping. Additionally, it caused no tissue damage or adhesions to surrounding tissues when applied to a liver hemorrhage in mice.

The hydrogel adhesive has numerous potential applications in the medical field, either as a patch that can be cut to desired sizes and applied to many tissues including bone, cartilage, tendon, or pleura, or as an injectable solution for deeper injuries. It can also be used to attach medical devices to their target structures, such as an actuator to support heart function. While the current iteration is designed to be a permanent structure, it could be made to biodegrade over time as the body heals from injury.

Source: https://wyss.harvard.edu/

Gene Therapy Combats Efficiently Age-related Diseases

As we age, our bodies tend to develop diseases like heart failure, kidney failure, diabetes, and obesity, and the presence of any one disease increases the risk of developing others. In traditional drug development, a drug usually only targets one condition, largely ignoring the interconnectedness of age-related diseases, such as obesity, diabetes, and heart failure, and requiring patients to take multiple drugs, which increases the risk of negative side effects.

A new study from the Wyss Institute for Biologically Inspired Engineering at Harvard University and Harvard Medical School (HMS) reports that a single administration of an adeno-associated virus (AAV)-based gene therapy delivering combinations of three longevity-associated genes to mice dramatically improved or completely reversed multiple age-related diseases, suggesting that a systems-level approach to treating such diseases could improve overall health and lifespan. The research is reported in PNAS.

The AAV-based gene therapy improved the function of the heart and other organs in mice with various age-related diseases, suggesting that such an approach could help maintain health during aging.

The results we saw were stunning, and suggest that holistically addressing aging via gene therapy could be more effective than the piecemeal approach that currently exists,” said first author Noah Davidsohn, Ph.D., a former Research Scientist at the Wyss Institute and HMS who is now the Chief Technology Officer of Rejuvenate Bio. “Everyone wants to stay as healthy as possible for as long as possible, and this study is a first step toward reducing the suffering caused by debilitating diseases.

The study was conducted in the lab of Wyss Core Faculty member George Church, Ph.D. as part of Davidsohn’s postdoctoral research into the genetics of aging. Davidsohn, Church, and their co-authors honed in on three genes that had previously been shown to confer increased health and lifespan benefits when their expression was modified in genetically engineered mice: FGF21, sTGFβR2, and αKlotho. They hypothesized that providing extra copies of those genes to non-engineered mice via gene therapy would similarly combat age-related diseases and confer health benefits.

The team created separate gene therapy constructs for each gene using the AAV8 serotype as a delivery vehicle, and injected them into mouse models of obesity, type II diabetes, heart failure, and renal failure both individually and in combination with the other genes to see if there was a synergistic beneficial effect.

Source; https://wyss.harvard.edu/