Author: lisaweiner

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Sensors Stem Cells

Hydrogel-coated sutures sense inflammation, can deliver drugs and stem cells

Giovanni Traverso has designed tough, absorbable, hydrogel-coated sutures, which in addition to holding post-surgery or wound-affected tissue in place, can sense inflammation and deliver drugs, including monoclonal antibodies. They could also be used to deliver stem cells.

The sutures were created from pig tissue, “decellularized” with detergents, to reduce the chances of inducing inflammation in host tissue. This process leaves behind a cell-free “De-gut” material, which contains structural proteins such as collagen, and other biomolecules found in the extracellular matrix that surrounds cells. Their strength is comparable to commercially available catgut sutures, and the De-gut sutures induce much less of an immune response from surrounding tissue.

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Brain Pharmaceuticals Ultrasound

Implanted ultrasound allows powerful chemotherapy drugs to cross the blood brain barrier

Adam Sonaband and Northwestern colleages used a skull-implantable ultrasound device to open the blood-brain barrier and repeatedly permeate critical regions of the human brain, to deliver intravenous chemotherapy to glioblastoma patients.

This is the first study to successfully quantify the effect of ultrasound-based blood-brain barrier opening on the concentrations of chemotherapy in the human brain. It showed a four- to six-fold increase in concentrations of paclitaxel and carboplatin, powerful drugs not currently used in glioblastoma because they did not cross the blood brain barrier. Temozolomide does cross the blood-brain barrier, but is weaker.

This is also the first study to describe how quickly the blood-brain barrier closes after sonication, allowing optimization of the sequence of drug delivery and ultrasound activation to maximize drug penetration.

The ultrasound implantation takes four minutes, and the patient is awake. It is the basis of an ongoing phase 2 clinical trial.

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Aging Brain

Study: Molecular mechanism of accelerated cognitive decline in women with Alzheimer’s

Hermona Soreq, Yonatan Loewenstein, and Hebrew University of Jerusalem colleagues have uncovered a sex-specific molecular mechanism leading to accelerated cognitive decline in women with Alzheimer’s disease.

Current therapeutic protocols are based on structural changes in the brain and aim to delay symptom progression. Women typically experience more severe side effects from these drugs.

This research shows that severe depletion of mitochondrial RNA fragments inherited from the mother, in the affected brain nuclei, correlates with the rapid deterioration of cognitive abilities in women with living Alzheimer’s.

Soreq explained: “Our research presents a significant contribution to the existing body of Alzheimer’s research by uncovering new insights into the factors driving accelerated cognitive decline in women, underscoring crucial distinctions not only in disease progression but also in treatment response.  Moreover, these findings have implications for treating these symptoms by RNA-based therapies, which emerged in recent years, and now present a viable option.”

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Cancer Heart Sensors

Wearable sensor evaluates human tissue stiffness

Sheng Xu and colleagues have developed a wearable, stretchable device that non-invasively evaluates the stiffness of human tissue, at an improved penetration depth, and for a longer period than, existing methods.

An ultrasonic array facilitates serial, non-invasive, three-dimensional imaging of tissues, four centimeters below the surface of human skin, at a spatial resolution of 0.5 millimeters.

The sensor can be used to detect cancer progression, which cases cells to stiffen; diagnose and treat sports injuries, by monitoring muscles, ligaments and tendons; and monitor the efficacy of treatments for liver, cardiovascular disease, and cancer, which cause tissue to stiffen.

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Brain Pharmaceuticals

Donanemab slowed memory decline by 35%, disease progression by 39%, in Alzheimer’s trial

Patients who received Eli Lily’s monthly donanemab infusion in an 18-month study demonstrated a 35% slower decline in memory, thinking, and ability to perform activities of daily living, and were 39% less likely to progress to the next stage of the disease. Brain plaque was also reduced significantly.

The risk of the drug is brain swelling and bleeding. Three trial participants died from these complications.

Lilly CSO/CMO Daniel Skovronsky said donanemab demonstrated the highest level of efficacy of any Alzheimer’s treatment in a clinical trial.

The company plans to apply for FDA approval in the coming months.

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Pain

Pain management via implanted, bioresorbable drug delivery device

John Rogers has developed a wireless, self-powered, bioresorbable implant for programmed drug delivery, enabling precision pain management.

When exposed to an external light source, the implant’s wavelength-sensitive phototransistor opens a gate, releasing a pre-loaded reservoir of a drug into the body. It dissolves after the regimen is complete, eliminating the need for surgery to remove it.

The device has been tested on rats, and will move to human trials after further safety tests.

John Rogers discussed soft electronics for the human body at the 2018 ApplySci conference at the MIT Media Lab.

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Brain

Music improves working memory in study of seniors

A study led by Damian Marie and UNIGE, HES-SO Geneva, and EPFL colleagues showed the effect of music on working memory decline.

132 healthy retirees from 62 to 78 years of age, who had not taken any lessons for at least six months, were assigned to two groups — piano practice, and active listening.

According to author Clara James: ”After six months, we found common effects for both interventions. Neuroimaging revealed an increase in grey matter in four brain regions involved in high-level cognitive functioning in all participants, including cerebellum areas involved in working memory. Their performance increased by 6% and this result was directly correlated to the plasticity of the cerebellum.” Quality of sleep, the number of lessons, and daily training time also had a positive impact on brain performance.

In the pianists, the volume of grey matter remained stable in the right primary auditory cortex. It decreased in the active listening group. A global brain pattern of atrophy was present in all participants, showing that while music can prevent aging in specific regions, the researchers could not yet conclude that music generally rejuvenates the brain.

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Heart Sensors

Proof of concept wrist sensor could detect heart-vessel blockage in 3-5 minutes

UW’s Graham Nichol and Harborview Medical Center colleagues studying the reliability of a troponin-detecting, wrist-worn sensor in arriving cardiac arrest patients.

Identifying heart-vessel blockage quickly is crucial to ensuring rapid, appropriate intervention. Traditional EKG diagnosis can lack accuracy, and blood testing for troponin can take hours.

The novel “Tropsensor,” being commercialized by rce, is designed to detect high troponin levels within three to five minutes of application, will be tested on 30 patients during emergency care at Harborview.

In a related Robert Wood Johnson study of 238 patients led by Partho Sengupta, a wrist worn transdermal infrared spectrophotometric sensor successfully identified elevated high-sensitivity cardiac troponin-I (hs-cTnI) levels in patients hospitalized with ACS.

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Sensors Wounds

Smart bandage based closed loop wound monitoring and treatment system

Caltech professor Wei Gao has developed a smart bandage for chronic wounds, made from a flexible and stretchy polymer containing embedded electronics and medication. The electronics allow the sensor to monitor uric acid, lactate, pH level and wound temperature, indicating inflammation or bacterial infection.

Data from the wound is transmitted wirelessly to the patient or doctor. Antibiotics (or other medication) stored within the bandage is released directly, as needed, to the wound site. A low-level electrical field can stimulate tissue growth, resulting in faster healing.

In animal models, the bandages provided real-time updates about wound conditions and metabolic states, and helped chronic infected wounds (similar to those found in humans) heal faster.

Wei Gao discussed skin-interfaced wearable biosensors at ApplySci Silicon Valley, held on Sand Hill road in 2020.

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Brain Sensors

Closed-loop sensor/stimulation system to detect, reduce neurological events

For the first time, there is an autonomous sensing and stimulating unit sitting in a specific brain region and ensuring that neuronal activity in that region is controlled. The closed-loop system is called NeuralTree and was developed by Mahsa Shoaran and EPFL colleagues, to overcome the lack of control caused by epileptic activity or tremor, and later depression, anxiety, OCD, and other disorders. In the future, the technology will be miniaturized, and could rely on internally harvested energy, such as blood flow or oxygen. It could then be possible to implant multiple units to aid the brain, when and where needed.

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Diabetes Sensors

In ear PPG used to measure blood glucose levels in proof of concept study

Danilo Mandic and Imperial College colleagues have developed a novel in-ear PPG device for continuous blood glucose level measurement, using the infrared wavelength of a pulse oximeter.

In a recent proof of concept study, non-diabetic, pre-diabetic, type I diabetic, and type II diabetic states were considered. Recordings spanned 9 days, in both fasting and post carbohydrate consumption states. Blood Glucose Levels from PPG were estimated using regression-based machine learning models. An average of 82% of the BGLs estimated from PPG were in region A of the Clarke error grid plot, and 100% of the estimated BGLs in clinically acceptable regions A and B. The researchers believe that this demonstrates the potential of the ear canal for non-invasive blood glucose monitoring.

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AI Brain

AI reconstructs viewed images

Yu Takagi, Shinji Nishimoto and Osaka University colleagues have published a  study which demonstrates that AI can read brain scans and re-create largely realistic versions of images a person has seen. Future applications could include enabling communication of people with paralysis, recording dreams, and understanding animal perception, among others.

Additional training was used on the existing text-to-image generative AI Stable Diffusion system, linking text descriptions about thousands of photos to brain patterns elicited when those photos were observed. Stable Diffusion was able to get more out of less training for each participant by incorporating photo captions into the algorithm.

The algorithm uses information gathered from regions of the brain involved in image perception, such as the occipital and temporal lobes. The system interpreted information from fMRI scans, detecting changes in blood flow to active brain regions. When people look at a photo, the temporal lobes register information about image contents (people, objects, or scenery), and the occipital lobe predominantly registers information about layout and perspective, such as the scale and position. This is recorded by the fMRI as it captures peaks in brain activity, and these patterns can then be reconverted into an imitation image using AI.