Liquid Composite May Restore Damaged Soft Tissue

2012-02-18T19:15:00.000-08:00

At Johns Hopkins, Biomedical Engineers have developed a new liquid material, made of hyaluronic acid and polyethylene glycol, to restore damaged soft tissue. The liquid is a composite of biological and synthetic molecules and is made into a solid structure with light after being injected under the skin. The advantage to having a material that is a composite of both biological and synthetic molecules is that synthetic materials are rejected by the immune system, but biological materials tend to be broken down by the body too quickly to be able to be used long-term. However, the composite allows for durability, as well as compatibility in the body. The hyaluronic acid is the biological component that is a natural component of skin in young people and the polyethylene glycol is the synthetic material that is commonly used as surgical glue in operations.

The biomedical researchers wanted the composite with the greatest long-term stability, so they tested many different concentrations under the skin and into the back muscle of rats. The implants were measured at 47 days and 110 days by an MRI and then removed. Once finding the concentration that not only stayed in place, but also was the same size overtime, the safety and persistence of the PEG-HA implants with a 12-week experiment in three volunteers already undergoing tummy-tuck surgery. During the experiment, none of the patients experienced any hospitalization, disability, or death that was related to the liquid composite. Once the implants were removed, some inflammation was noted around the implants due to certain types of white blood cells. This inflammation was also seen in the rats, but the types of white blood cells that caused it differed between rats and humans. The next step for the Johns Hopkins team is going to be to evaluate the liquid composite in different tissues in humans to see how it reacts. This will allow them to optimize the liquid composite for different procedures.

Currently, as stated above, the liquid material has shown promise in rats and humans, but is not ready to be used in widespread clinical use. The team hopes that the liquid composite will be help people with facial deformities, who undergo social and psychological trauma on a daily basis.

Source:

http://insciences.org/article.php?article_id=10260

DEVICE TRACKS BLOOD FLOW IN BRAIN

2012-02-18T16:17:00.000-08:00

"Headset ultrasound monitor that detects the after effects of the brain injuries in patients”

Cerebral Vasospasm is a condition where the lumen of the brain blood vessel narrows because of overcontraction of the vessel wall which can lead to tissue ischemia or even death. It can develop several days after an initial injury; it is found most often in soldiers with blast related injuries and also in patients with cerebral aneurysms.

The existing technology for this condition is currently detected using ultrasound and requires a technician who is trained in the procedure of identifying the blood vessels and holding the beam in position. However, PhysioSonics in Bellevue, Washington, has developed a monitor that eliminates the technician and therefore, makes the entire process automatic. This company is currently in the process of innovating the device for military use. The existing monitor directs an array of ultrasound beams and uses an algorithm to detect the affected artery in the brain. Then, it measures the perfusion and the pressure in the brain and records the velocity along with the index of flow. This type of monitoring involves an invasive procedure (drilling hole into the skull), so the device serves as surrogate for direct pressure data and measurements. Although, the monitor detects the blood flow continuously which makes it easier to track the flow over time; in fact, it is not yet sensitive enough to detect or signal danger. Currently, the company has conducted clinical studies and making the necessary changes for detecting this dangerous condition.
http://www.technologyreview.com/biomedicine/39313/?mod=chthumb
http://www.brain-aneurysm.com/cv.html

Bioengineers at Work

Liquid Composite May Restore Damaged Soft Tissue

DEVICE TRACKS BLOOD FLOW IN BRAIN