A new advance in bioengineering offers researchers an unprecedented look at astrocytes, the most abundant cells in the human brain and key players in neurological health [[1]]. These star-shaped cells, long recognized for their crucial role in brain function, have been difficult to study in laboratory settings due to challenges in replicating their natural surroundings. Now, a team from Johns Hopkins University and the National Research Council of Italy has developed a novel nanowire platform that allows for detailed observation of astrocytes *in vitro*, possibly opening new avenues for understanding and treating neurological disorders [[2]], including Alzheimer’s and Parkinson’s disease [[3]].
A new biotechnological innovation is gaining attention: nanofilaments of amorphous glass that provide a unique environment for astrocytes, the star-shaped cells vital to brain function.
Astrocytes, found in the brain and spinal cord, are named for their distinctive star-like shape – derived from the Greek words astro (star) and cyte (cell). These cells play a critical role in maintaining the stability of the central nervous system, regulating communication between neurons and interacting with the surrounding environment. Despite being the most abundant cell type in the brain, astrocytes remain poorly understood, largely due to the difficulty of replicating their complex behavior in laboratory settings and accurately measuring their characteristics with conventional medical imaging techniques. Now, researchers at Johns Hopkins University (Baltimore, Maryland) and the National Research Council of Italy have made a significant breakthrough in observing the star-shaped morphology of astrocytes grown on specially designed nanostructured surfaces. Their findings were detailed in the November 3, 2025, issue of the journal Advanced Science.
A “Slipper” of Glass for Astrocytes
The researchers developed a platform using nanowires made of disordered glass. These nanowires were created by oxidizing silicon nanowires at 980°C in an oxygen-rich atmosphere for eight hours. This process resulted in amorphous glass nanowires with a slightly larger diameter – between 80 and 180 nanometers, compared to the original 50 to 80 nanometers. To observe how astrocytes responded to this new substrate, the research team utilized low-coherence holotomography, a laser-based technique that measures the three-dimensional refractive index tomogram of microscopic samples like cells. The team observed that astrocytes derived from rat cortical cells exhibited a morphology similar to that seen in living tissue.
Specifically, the astrocytes didn’t adopt a simple rounded shape, but instead displayed a main body (soma) ranging from 200 to 250 µm2, from which up to six primary branches extended. 48% of these branches had secondary extensions, and 9% even developed tertiary branches. The total length of the branching structure typically fell between 100 and 150 µm. This branching pattern indicates that the astrocytes were in a state closely resembling their natural, mature condition. This advancement promises to improve our understanding of both healthy brain function and neurological disorders, as malfunctioning astrocytes have been linked to conditions like Alzheimer’s and Parkinson’s disease. Further research could reveal crucial insights into the origins of these neurodegenerative diseases.
