The hydrogel delivers therapeutic molecules to the brain after stroke, promoting blood vessel renewal and aiding recovery.
Scientists in Korea have developed a technique to regenerate blood vessels within the brain after a stroke using a gelatinous hydrogel that could be saturated with therapeutic molecules and injected directly at the positioning of injury.
Ischemic stroke, a catastrophic blockage of blood flow to the brain, is usually fatal, and even when the patient survives, the likelihood of everlasting brain damage stays high. “There was a stroke second place within the lead [global] reason behind death in 2019answerable for 11.6% of all deaths,” said Sunggu Yang, a researcher at Incheon National University in Korea and chief scientist for test published in the outline of the hydrogel treatment.
“Ischemic stroke is a condition caused by blockage of blood vessels that prevents the flow of nutrients and oxygen, leading to damage to brain tissue,” Yang added.
Current treatments for ischemic stroke are relatively easy and give attention to removing the blockages using drugs or invasive tools equivalent to stents or catheters. Although removing the blockage is crucial, it doesn’t repair or restore damaged blood vessels or brain tissue, leaving the affected area prone to impaired blood flow and a greater risk of one other stroke.
“Therefore, the key to treatment is blood vessel regeneration,” Yang said.
Overcoming the blood-brain barrier
Angiogenesis, the technique of regenerating latest blood vessels, could be stimulated within the body using molecules called angiogenic aspects. These are growth aspects and other products produced by the body to signal and stimulate blood vessel growth.
However, the issue in using them to treat the sequelae of stroke is the effective delivery of those molecules to the brain. “The brain has a blood-brain barrier that protects against drug penetration,” Yang said.
This barrier protects the brain against infection by stopping most molecules within the blood from entering, however it also blocks life-saving drugs.
Injections can bypass this barrier, but brain cells often break down drugs quickly. To address this, you would like a carrier — a type of Trojan horse — that cannot only bypass the barrier but in addition protect the drug while it does its job.
For this purpose, the team turned to hydrogels.
Hydrogels are a form of polymers, i.e. substances product of long chains of molecules. Some types of hydrogels are increasingly utilized in biomedical applications because they don’t trigger immune reactions, are biodegradable, and could be full of biologically lively molecules.
“When a drug is delivered in the form of a hydrogel, the hydrogel acts as a protective carrier,” Yang said. “The drug slowly diffuses out of the hydrogel over time, and the hydrogel protects the drug until it is completely broken down.”
Yang believed this sustained release would aid in recovery from stroke without the necessity for repeated injections.
Repairing damage, restoring blood flow
To test this concept, the team administered the hydrogel therapy on to the brain in a rodent model of ischemic stroke. “Our injectable hydrogel containing angiogenic factors was very effective in promoting and improving angiogenesis [motor] function,” Yang said.
Surprisingly, tests showed that the hydrogels themselves also promoted blood vessel growth and improved sensory and motor functions. “Our findings suggest that the hydrogels themselves can promote angiogenesis, which may promote tissue regeneration and enhance sensorimotor function,” Yang said.
While promising, there remain several questions that must be answered. For example, the team needs to find out the speed at which the gel actually degrades within the body. Until then, scientists cannot say how quickly or how far the drug load will spread.
“This makes determining the optimal volume of hydrogel and the specific area of the damaged area to inject to maximize the effectiveness of stroke treatment challenging,” Yang explained.
The team can be investigating combos of growth aspects and molecules that help regenerate brain tissue lost during stroke, in addition to blood vessels. Restoring blood flow prevents further damage, but recovering the lost brain cells would further improve the patient’s probabilities of a full recovery.
Hydrogels still must undergo clinical trials before they’re ready to be used in humans, but this study adds to the growing potential of hydrogels as drug delivery systems to hard-to-reach places within the human body.
