Also: News on Alzheimer’s disease, zinc lozenges
Insulin patches for replacing shots
UCLA bioengineers and colleagues at UNC School of Medicine and MIT are continuing to report success in the development of a smart insulin-delivery patch that could one day monitor and manage glucose levels in people with diabetes and deliver the necessary insulin dosage. The adhesive patch, about the size of a quarter, is simple to manufacture and intended for once-a-day use.
Study investigator Zhen Gu, PhD, who is a professor of bioengineering at the UCLA Samueli School of Engineering, said animal studies have been completed and clinical trials are now planned. “Our main goal is to enhance health and improve the quality of life for people who have diabetes,” said Gu, a former professor in the UNC/NCSU Joint Department of Biomedical Engineering. “This smart patch takes away the need to constantly check one’s blood sugar and then inject insulin if and when it’s needed. It mimics the regulatory function of the pancreas but in a way that’s easy to use.”
The adhesive patch monitors blood sugar, or glucose and delivers doses of insulin pre-loaded in very tiny microneedles, less than one-millimeter in length that deliver medicine quickly when the blood sugar levels reach a certain threshold. When blood sugar returns to normal, the patch’s insulin delivery also slows down. The researchers said the advantage is that it can help prevent overdosing of insulin, which can lead to hypoglycemia and other serious complications.
“It has always been a dream to achieve insulin-delivery in a smart and convenient manner,” said study investigator Dr. John Buse, who is the director of the UNC Diabetes Center and the North Carolina Translational and Clinical Sciences (NC TraCS) Institute at the University of North Carolina at Chapel Hill School of Medicine. “This smart insulin patch, if proven safe and effective in human trials, would revolutionize the patient experience of diabetes care.”
Insulin is a hormone naturally produced in the pancreas that helps the body regulate glucose, which comes from food-consumption and provides the body with energy. Insulin is the molecular key that helps move glucose from the bloodstream to the cells for energy and storage.
The microneedles used in the patch are made with a glucose-sensing polymer that’s encapsulated with insulin. Once applied on the skin, the microneedles penetrate under the skin and can sense blood sugar levels. If glucose levels go up, the polymer is triggered to release the insulin. Each microneedle is smaller than a regular needle used to draw blood and do not reach as deeply, so the patch is less painful than a pin prick. Each microneedle penetrates about a half millimeter below the skin, which is sufficient to deliver insulin into the body.
A new approach to Alzheimer’s disease
Researchers say they have identified a previously unknown gene and associated protein, which they have named aggregatin, that could potentially be suppressed to slow the advance of Alzheimer’s disease. A team of investigators has completed the first systematic work combining the identification from a genome-wide association study of high dimensional brain-imaging data and experimental validation in Alzheimer’s disease.
“Based on the data we have, this protein can be an unrecognized new risk factor for Alzheimer’s disease,” said Xinglong Wang, an associate professor of pathology at Case Western University School of Medicine, Cleveland, Ohio. “We also see this as a potential novel therapeutic target for this devastating disease.”
Wang said aggregatin accumulates, or aggregates, within the center of plaque in patients with Alzheimer’s disease, like the yolk of an egg. However, it may now be possible to develop new agents to prevent this process from occurring. More than 5.7 million Americans have Alzheimer’s disease, which is the primary cause of dementia and sixth-leading cause of death in the United States. That population is predicted to reach 14 million by the year 2050, according to the Alzheimer’s Association.
The relationship between Alzheimer’s and subsequent brain atrophy due to amyloid-beta in the brain is well established. However, there is less understood about precisely how that amyloid-beta actually leads to plaque formations in the brain causing memory loss. The researchers began by correlating roughly a million genetic markers (called single-nucleotide polymorphisms, or SNPs) with brain images. They were able to identify a specific SNP in the FAM222, a gene linked to different patterns of regional brain atrophy. Further experiments then suggested that the protein encoded by gene FAM222A is not only associated with AD patient-related beta-amyloid plaques and regional brain atrophy, but that aggregatin attaches to amyloid beta peptide.
Their findings indicate that reducing levels of this protein and inhibition of its interaction with amyloid beta peptide could potentially be therapeutic and help attack Alzheimer’s disease in a whole new way.
Jury still out on zinc lozenges for treating colds
It may be time to reconsider taking zinc acetate lozenges to treat the common cold. Eight controlled trials previously reported that zinc lozenges reduced the duration of the common cold, but several other trials did not find any benefit. Variation in the types of zinc lozenges has been proposed as one explanation for the mixed study findings. Many studies with negative findings used lozenges that had low doses of zinc or contained ingredients such as citric acid that bind zinc ions, preventing the release of free zinc in the oropharyngeal region. Now, it appears that further research is warranted to determine the conditions when zinc lozenges may be effective and the type and dosage of lozenges that may be optimal.
In a new randomized, double-blind placebo-controlled trial, Dr. Harri Hemilä from the University of Helsinki, Finland, and his colleagues investigated the effect of zinc acetate lozenges on employees of the City of Helsinki, Finland. To minimize the delay between the onset of common cold symptoms and the initiation of treatment, the participants were administered a package of lozenges with an instruction to start treatment as soon as feasible after the onset of symptoms. Participants were instructed to slowly dissolve 6 lozenges per day in their mouth with a total zinc dose of 78 mg/day zinc for five days.
During the trial, 88 participants contracted the common cold and started to use lozenges. No difference in the rate of recovery from the common cold was observed between the zinc and the placebo groups during the five-day treatment period. Unexpectedly, after the end of the five-day treatment period, participants in the zinc group recovered less rapidly than in the placebo group. This potential adverse effect after active treatment needs to be confirmed or refuted by future studies.
“Our study does not confirm the usefulness of zinc lozenges for treating the common cold, but neither does it refute the previous studies where zinc lozenges were found to be effective,” said Dr. Hemilä. “In future trials of zinc lozenges, the dosage of zinc should be greater, the lozenges should dissolve more slowly, and the treatment should last longer than five days. Before zinc lozenges can be widely promoted for common cold treatment, the characteristics of lozenges that are clinically efficacious should be defined in detail.”
John Schieszer is an award-winning national journalist and radio and podcast broadcaster of The Medical Minute. He can be reached at medicalminutes@gmail.com.
John Schieszer is an award-winning national journalist and radio and podcast broadcaster of The Medical Minute.
