Clarissa Brincat

Modern technology for recording deep-brain activity involves sharp metal electrodes that penetrate the tissue, causing damage that can compromise the signal and limiting how often they can be used. 

A rapidly growing area in materials science and engineering aims to fix the problem by designing electrodes that are softer, smaller, and flexible — safer for use inside the delicate tissues of the brain. On January 17, researchers from the University of California, San Diego, reported the development of a thin, flexible electrode that can be inserted deep within the brain and communicate with sensors on the surface. 

But what if you could record detailed deep-brain activity without piercing the brain? 

A team of researchers (as it happens, also from UC San Diego) have developed a thin, flexible implant that “resides on the brain’s surface” and “can infer neural activity from deeper layers,” said Duygu Kuzum, PhD, a professor of electrical and computer engineering, who led the research. 

By combining electrical and optical imaging methods, and artificial intelligence, the researchers used the device — a polymer strip packed with graphene electrodes — to predict deep calcium activity from surface signals, according to a proof-of-concept study published this month in Nature Nanotechnology. 

“Almost everything we know about how neurons behave in living brains comes from data collected with either electrophysiology or two-photon imaging,” said neuroscientist Joshua H. Siegle, PhD, of the Allen Institute for Neural Dynamics in Seattle , who not involved in the study. “ Until now, these two methods have rarely been used simultaneously.”

The technology, which has been tested in mice, could help advance our knowledge of how the brain works and may lead to new minimally invasive treatments for neurologic disorders. 
 

Multimodal Neurotech: The Power of 2-in-1

Electrical and optical methods for recording brain activity have been crucial in advancing neurophysiologic science, but each technique has its limits. Electrical recordings provide high “temporal resolution”; they reveal when activation is happening, but not really where. Optical imaging, on the other hand, offers high “spatial resolution,” showing which area of the brain is lighting up, but its measurements may not correspond with the activity’s timing. 

Research over the past decade has explored how to combine and harness the strengths of both methods. One potential solution is to use electrodes made of transparent materials such as graphene, allowing a clear field of view for a microscope during imaging. Recently, University of Pennsylvania scientists used graphene electrodes to illuminate the neural dynamics of seizures. 

But there are challenges. If graphene electrodes are very small — in this case, 20 µm in diameter — they become more resistant to the flow of electricity. Dr. Kuzum and colleagues addressed this by adding tiny platinum particles to improve electrical conductivity. Long graphene wires connect electrodes to the circuit board, but defects in graphene can interrupt the signal, so they made each wire with two layers; any defects in one wire could be hidden by the other.

By combining the two methods (microelectrode arrays and two-photon imaging), the researchers could see both when brain activity was happening and where, including in deeper layers. They discovered a correlation between electrical responses on the surface and cellular calcium activity deeper down. The team used these data to create a neural network (a type of artificial intelligence that learns to recognize patterns) that predicts deep calcium activity from surface-level readings.

The tech could help scientists study brain activity “in a way not possible with current single-function tools,” said Luyao Lu, PhD, professor of biomedical engineering at George Washington University in Washington, DC, who was not involved in the study. It could shed light on interactions between vascular and electrical activity, or explain how place cells (neurons in the hippocampus) are so efficient at creating spatial memory. 

It could also pave the way for minimally invasive neural prosthetics or targeted treatments for neurologic disorders, the researchers say. Implanting the device would be a “straightforward process” similar to placing electrocorticography grids in patients with epilepsy, said Dr. Kuzum. 

But first, the team plans to do more studies in animal models before testing the tech in clinical settings, Dr. Kuzum added.

A version of this article appeared on Medscape.com.

Modern technology for recording deep-brain activity involves sharp metal electrodes that penetrate the tissue, causing damage that can compromise the signal and limiting how often they can be used. 

A rapidly growing area in materials science and engineering aims to fix the problem by designing electrodes that are softer, smaller, and flexible — safer for use inside the delicate tissues of the brain. On January 17, researchers from the University of California, San Diego, reported the development of a thin, flexible electrode that can be inserted deep within the brain and communicate with sensors on the surface. 

But what if you could record detailed deep-brain activity without piercing the brain? 

A team of researchers (as it happens, also from UC San Diego) have developed a thin, flexible implant that “resides on the brain’s surface” and “can infer neural activity from deeper layers,” said Duygu Kuzum, PhD, a professor of electrical and computer engineering, who led the research. 

By combining electrical and optical imaging methods, and artificial intelligence, the researchers used the device — a polymer strip packed with graphene electrodes — to predict deep calcium activity from surface signals, according to a proof-of-concept study published this month in Nature Nanotechnology. 

“Almost everything we know about how neurons behave in living brains comes from data collected with either electrophysiology or two-photon imaging,” said neuroscientist Joshua H. Siegle, PhD, of the Allen Institute for Neural Dynamics in Seattle , who not involved in the study. “ Until now, these two methods have rarely been used simultaneously.”

The technology, which has been tested in mice, could help advance our knowledge of how the brain works and may lead to new minimally invasive treatments for neurologic disorders. 
 

Multimodal Neurotech: The Power of 2-in-1

Electrical and optical methods for recording brain activity have been crucial in advancing neurophysiologic science, but each technique has its limits. Electrical recordings provide high “temporal resolution”; they reveal when activation is happening, but not really where. Optical imaging, on the other hand, offers high “spatial resolution,” showing which area of the brain is lighting up, but its measurements may not correspond with the activity’s timing. 

Research over the past decade has explored how to combine and harness the strengths of both methods. One potential solution is to use electrodes made of transparent materials such as graphene, allowing a clear field of view for a microscope during imaging. Recently, University of Pennsylvania scientists used graphene electrodes to illuminate the neural dynamics of seizures. 

But there are challenges. If graphene electrodes are very small — in this case, 20 µm in diameter — they become more resistant to the flow of electricity. Dr. Kuzum and colleagues addressed this by adding tiny platinum particles to improve electrical conductivity. Long graphene wires connect electrodes to the circuit board, but defects in graphene can interrupt the signal, so they made each wire with two layers; any defects in one wire could be hidden by the other.

By combining the two methods (microelectrode arrays and two-photon imaging), the researchers could see both when brain activity was happening and where, including in deeper layers. They discovered a correlation between electrical responses on the surface and cellular calcium activity deeper down. The team used these data to create a neural network (a type of artificial intelligence that learns to recognize patterns) that predicts deep calcium activity from surface-level readings.

The tech could help scientists study brain activity “in a way not possible with current single-function tools,” said Luyao Lu, PhD, professor of biomedical engineering at George Washington University in Washington, DC, who was not involved in the study. It could shed light on interactions between vascular and electrical activity, or explain how place cells (neurons in the hippocampus) are so efficient at creating spatial memory. 

It could also pave the way for minimally invasive neural prosthetics or targeted treatments for neurologic disorders, the researchers say. Implanting the device would be a “straightforward process” similar to placing electrocorticography grids in patients with epilepsy, said Dr. Kuzum. 

But first, the team plans to do more studies in animal models before testing the tech in clinical settings, Dr. Kuzum added.

A version of this article appeared on Medscape.com.

Modern technology for recording deep-brain activity involves sharp metal electrodes that penetrate the tissue, causing damage that can compromise the signal and limiting how often they can be used. 

A rapidly growing area in materials science and engineering aims to fix the problem by designing electrodes that are softer, smaller, and flexible — safer for use inside the delicate tissues of the brain. On January 17, researchers from the University of California, San Diego, reported the development of a thin, flexible electrode that can be inserted deep within the brain and communicate with sensors on the surface. 

But what if you could record detailed deep-brain activity without piercing the brain? 

A team of researchers (as it happens, also from UC San Diego) have developed a thin, flexible implant that “resides on the brain’s surface” and “can infer neural activity from deeper layers,” said Duygu Kuzum, PhD, a professor of electrical and computer engineering, who led the research. 

By combining electrical and optical imaging methods, and artificial intelligence, the researchers used the device — a polymer strip packed with graphene electrodes — to predict deep calcium activity from surface signals, according to a proof-of-concept study published this month in Nature Nanotechnology. 

“Almost everything we know about how neurons behave in living brains comes from data collected with either electrophysiology or two-photon imaging,” said neuroscientist Joshua H. Siegle, PhD, of the Allen Institute for Neural Dynamics in Seattle , who not involved in the study. “ Until now, these two methods have rarely been used simultaneously.”

The technology, which has been tested in mice, could help advance our knowledge of how the brain works and may lead to new minimally invasive treatments for neurologic disorders. 
 

Multimodal Neurotech: The Power of 2-in-1

Electrical and optical methods for recording brain activity have been crucial in advancing neurophysiologic science, but each technique has its limits. Electrical recordings provide high “temporal resolution”; they reveal when activation is happening, but not really where. Optical imaging, on the other hand, offers high “spatial resolution,” showing which area of the brain is lighting up, but its measurements may not correspond with the activity’s timing. 

Research over the past decade has explored how to combine and harness the strengths of both methods. One potential solution is to use electrodes made of transparent materials such as graphene, allowing a clear field of view for a microscope during imaging. Recently, University of Pennsylvania scientists used graphene electrodes to illuminate the neural dynamics of seizures. 

But there are challenges. If graphene electrodes are very small — in this case, 20 µm in diameter — they become more resistant to the flow of electricity. Dr. Kuzum and colleagues addressed this by adding tiny platinum particles to improve electrical conductivity. Long graphene wires connect electrodes to the circuit board, but defects in graphene can interrupt the signal, so they made each wire with two layers; any defects in one wire could be hidden by the other.

By combining the two methods (microelectrode arrays and two-photon imaging), the researchers could see both when brain activity was happening and where, including in deeper layers. They discovered a correlation between electrical responses on the surface and cellular calcium activity deeper down. The team used these data to create a neural network (a type of artificial intelligence that learns to recognize patterns) that predicts deep calcium activity from surface-level readings.

The tech could help scientists study brain activity “in a way not possible with current single-function tools,” said Luyao Lu, PhD, professor of biomedical engineering at George Washington University in Washington, DC, who was not involved in the study. It could shed light on interactions between vascular and electrical activity, or explain how place cells (neurons in the hippocampus) are so efficient at creating spatial memory. 

It could also pave the way for minimally invasive neural prosthetics or targeted treatments for neurologic disorders, the researchers say. Implanting the device would be a “straightforward process” similar to placing electrocorticography grids in patients with epilepsy, said Dr. Kuzum. 

But first, the team plans to do more studies in animal models before testing the tech in clinical settings, Dr. Kuzum added.

A version of this article appeared on Medscape.com.

As revolutionary as glucagon-like peptide 1 (GLP-1) drugs are, they still last for only so long in the body. Patients with diabetes typically must be injected once or twice a day (liraglutide) or once a week (semaglutide). This could hinder proper diabetes management, as adherence tends to go down the more frequent the dose. 

But what if a single GLP-1 injection could last for 4 months?

Stanford engineers have developed an injectable hydrogel depot that releases GLP-1 slowly as the hydrogel gradually “melts away like a sugar cube dissolving in water, molecule by molecule,” said Eric Appel, PhD, the project’s principal investigator and an associate professor of materials science and engineering at Stanford (Calif.) University.

So far, the team has tested the new drug delivery system in rats, and they say human clinical trials could start within 2 years.

Mathematical modeling indicated that one shot of liraglutide could maintain exposure in humans for 120 days, or about 4 months, according to their study in Cell Reports Medicine.

“Patient adherence is of critical importance to diabetes care,” said Alex Abramson, PhD, assistant professor in the chemical and biomolecular engineering department at Georgia Tech, who was not involved in the study. “It’s very exciting to have a potential new system that can last 4 months on a single injection.”

Long-Acting Injectables Have Come a Long Way

The first long-acting injectable — Lupron Depot, a monthly treatment for advanced prostate cancer — was approved in 1989. Since then, long-acting injectable depots have revolutionized the treatment and management of conditions ranging from osteoarthritis knee pain to schizophrenia to opioid use disorder. In 2021, the US Food and Drug Administration approved Apretude — an injectable treatment for HIV pre-exposure prevention that needs to be given every 2 months, compared with daily for the pill equivalent. Other new and innovative developments are underway: Researchers at the University of Connecticut are working on a transdermal microneedle patch — with many tiny vaccine-loaded needles — that could provide multiple doses of a vaccine over time, no boosters needed.

At Stanford, Appel’s lab has spent years developing gels for drug delivery. His team uses a class of hydrogel called polymer-nanoparticle (PNP), which features weakly bound polymers and nanoparticles that can dissipate slowly over time.

The goal is to address a longstanding challenge with long-acting formulations: Achieving steady release. Because the hydrogel is “self-healing” — able to repair damages and restore its shape — it’s less likely to burst and release its drug cargo too early. 

“Our PNP hydrogels possess a number of really unique characteristics,” Dr. Appel said. They have “excellent” biocompatibility, based on animal studies, and could work with a wide range of drugs. In proof-of-concept mouse studies, Dr. Appel and his team have shown that these hydrogels could also be used to make vaccines last longer, ferry cancer immunotherapies directly to tumors, and deliver antibodies for the prevention of infectious diseases like SARS-CoV-2.

Though the recent study on GLP-1s focused on treating type 2 diabetes, the same formulation could also be used to treat obesity, said Dr. Appel.

The researchers tested the tech using two GLP-1 receptor agonists — semaglutide and liraglutide. In rats, one shot maintained therapeutic serum concentrations of semaglutide or liraglutide over 42 days. With semaglutide, a significant portion was released quickly, followed by controlled release. Liraglutide, on the other hand, was released gradually as the hydrogel dissolved. This suggests the liraglutide hydrogel may be better tolerated, as a sudden peak in drug serum concentration is associated with adverse effects.

The researchers used pharmacokinetic modeling to predict how liraglutide would behave in humans with a larger injection volume, finding that a single dose could maintain therapeutic levels for about 4 months.

“Moving forward, it will be important to determine whether a burst release from the formulation causes any side effects,” Dr. Abramson noted. “Furthermore, it will be important to minimize the injection volumes in humans.”

But first, more studies in larger animals are needed. Next, Dr. Appel and his team plan to test the technology in pigs, whose skin and endocrine systems are most like humans’. If those trials go well, Dr. Appel said, human clinical trials could start within 2 years.
 

A version of this article appeared on Medscape.com.

As revolutionary as glucagon-like peptide 1 (GLP-1) drugs are, they still last for only so long in the body. Patients with diabetes typically must be injected once or twice a day (liraglutide) or once a week (semaglutide). This could hinder proper diabetes management, as adherence tends to go down the more frequent the dose. 

But what if a single GLP-1 injection could last for 4 months?

Stanford engineers have developed an injectable hydrogel depot that releases GLP-1 slowly as the hydrogel gradually “melts away like a sugar cube dissolving in water, molecule by molecule,” said Eric Appel, PhD, the project’s principal investigator and an associate professor of materials science and engineering at Stanford (Calif.) University.

So far, the team has tested the new drug delivery system in rats, and they say human clinical trials could start within 2 years.

Mathematical modeling indicated that one shot of liraglutide could maintain exposure in humans for 120 days, or about 4 months, according to their study in Cell Reports Medicine.

“Patient adherence is of critical importance to diabetes care,” said Alex Abramson, PhD, assistant professor in the chemical and biomolecular engineering department at Georgia Tech, who was not involved in the study. “It’s very exciting to have a potential new system that can last 4 months on a single injection.”

Long-Acting Injectables Have Come a Long Way

The first long-acting injectable — Lupron Depot, a monthly treatment for advanced prostate cancer — was approved in 1989. Since then, long-acting injectable depots have revolutionized the treatment and management of conditions ranging from osteoarthritis knee pain to schizophrenia to opioid use disorder. In 2021, the US Food and Drug Administration approved Apretude — an injectable treatment for HIV pre-exposure prevention that needs to be given every 2 months, compared with daily for the pill equivalent. Other new and innovative developments are underway: Researchers at the University of Connecticut are working on a transdermal microneedle patch — with many tiny vaccine-loaded needles — that could provide multiple doses of a vaccine over time, no boosters needed.

At Stanford, Appel’s lab has spent years developing gels for drug delivery. His team uses a class of hydrogel called polymer-nanoparticle (PNP), which features weakly bound polymers and nanoparticles that can dissipate slowly over time.

The goal is to address a longstanding challenge with long-acting formulations: Achieving steady release. Because the hydrogel is “self-healing” — able to repair damages and restore its shape — it’s less likely to burst and release its drug cargo too early. 

“Our PNP hydrogels possess a number of really unique characteristics,” Dr. Appel said. They have “excellent” biocompatibility, based on animal studies, and could work with a wide range of drugs. In proof-of-concept mouse studies, Dr. Appel and his team have shown that these hydrogels could also be used to make vaccines last longer, ferry cancer immunotherapies directly to tumors, and deliver antibodies for the prevention of infectious diseases like SARS-CoV-2.

Though the recent study on GLP-1s focused on treating type 2 diabetes, the same formulation could also be used to treat obesity, said Dr. Appel.

The researchers tested the tech using two GLP-1 receptor agonists — semaglutide and liraglutide. In rats, one shot maintained therapeutic serum concentrations of semaglutide or liraglutide over 42 days. With semaglutide, a significant portion was released quickly, followed by controlled release. Liraglutide, on the other hand, was released gradually as the hydrogel dissolved. This suggests the liraglutide hydrogel may be better tolerated, as a sudden peak in drug serum concentration is associated with adverse effects.

The researchers used pharmacokinetic modeling to predict how liraglutide would behave in humans with a larger injection volume, finding that a single dose could maintain therapeutic levels for about 4 months.

“Moving forward, it will be important to determine whether a burst release from the formulation causes any side effects,” Dr. Abramson noted. “Furthermore, it will be important to minimize the injection volumes in humans.”

But first, more studies in larger animals are needed. Next, Dr. Appel and his team plan to test the technology in pigs, whose skin and endocrine systems are most like humans’. If those trials go well, Dr. Appel said, human clinical trials could start within 2 years.
 

A version of this article appeared on Medscape.com.

As revolutionary as glucagon-like peptide 1 (GLP-1) drugs are, they still last for only so long in the body. Patients with diabetes typically must be injected once or twice a day (liraglutide) or once a week (semaglutide). This could hinder proper diabetes management, as adherence tends to go down the more frequent the dose. 

But what if a single GLP-1 injection could last for 4 months?

Stanford engineers have developed an injectable hydrogel depot that releases GLP-1 slowly as the hydrogel gradually “melts away like a sugar cube dissolving in water, molecule by molecule,” said Eric Appel, PhD, the project’s principal investigator and an associate professor of materials science and engineering at Stanford (Calif.) University.

So far, the team has tested the new drug delivery system in rats, and they say human clinical trials could start within 2 years.

Mathematical modeling indicated that one shot of liraglutide could maintain exposure in humans for 120 days, or about 4 months, according to their study in Cell Reports Medicine.

“Patient adherence is of critical importance to diabetes care,” said Alex Abramson, PhD, assistant professor in the chemical and biomolecular engineering department at Georgia Tech, who was not involved in the study. “It’s very exciting to have a potential new system that can last 4 months on a single injection.”

Long-Acting Injectables Have Come a Long Way

The first long-acting injectable — Lupron Depot, a monthly treatment for advanced prostate cancer — was approved in 1989. Since then, long-acting injectable depots have revolutionized the treatment and management of conditions ranging from osteoarthritis knee pain to schizophrenia to opioid use disorder. In 2021, the US Food and Drug Administration approved Apretude — an injectable treatment for HIV pre-exposure prevention that needs to be given every 2 months, compared with daily for the pill equivalent. Other new and innovative developments are underway: Researchers at the University of Connecticut are working on a transdermal microneedle patch — with many tiny vaccine-loaded needles — that could provide multiple doses of a vaccine over time, no boosters needed.

At Stanford, Appel’s lab has spent years developing gels for drug delivery. His team uses a class of hydrogel called polymer-nanoparticle (PNP), which features weakly bound polymers and nanoparticles that can dissipate slowly over time.

The goal is to address a longstanding challenge with long-acting formulations: Achieving steady release. Because the hydrogel is “self-healing” — able to repair damages and restore its shape — it’s less likely to burst and release its drug cargo too early. 

“Our PNP hydrogels possess a number of really unique characteristics,” Dr. Appel said. They have “excellent” biocompatibility, based on animal studies, and could work with a wide range of drugs. In proof-of-concept mouse studies, Dr. Appel and his team have shown that these hydrogels could also be used to make vaccines last longer, ferry cancer immunotherapies directly to tumors, and deliver antibodies for the prevention of infectious diseases like SARS-CoV-2.

Though the recent study on GLP-1s focused on treating type 2 diabetes, the same formulation could also be used to treat obesity, said Dr. Appel.

The researchers tested the tech using two GLP-1 receptor agonists — semaglutide and liraglutide. In rats, one shot maintained therapeutic serum concentrations of semaglutide or liraglutide over 42 days. With semaglutide, a significant portion was released quickly, followed by controlled release. Liraglutide, on the other hand, was released gradually as the hydrogel dissolved. This suggests the liraglutide hydrogel may be better tolerated, as a sudden peak in drug serum concentration is associated with adverse effects.

The researchers used pharmacokinetic modeling to predict how liraglutide would behave in humans with a larger injection volume, finding that a single dose could maintain therapeutic levels for about 4 months.

“Moving forward, it will be important to determine whether a burst release from the formulation causes any side effects,” Dr. Abramson noted. “Furthermore, it will be important to minimize the injection volumes in humans.”

But first, more studies in larger animals are needed. Next, Dr. Appel and his team plan to test the technology in pigs, whose skin and endocrine systems are most like humans’. If those trials go well, Dr. Appel said, human clinical trials could start within 2 years.
 

A version of this article appeared on Medscape.com.