Precisely patterned molecular threads boost neuron growth and synapse formation in cell cultures
Northwestern University scientists have developed remarkably long, precisely patterned molecular threads that could open new possibilities for designing advanced materials. The scientists also discovered that these threads—called ...
Built from self-assembling molecules, the longest threads reach lengths greater than the diameter of a cell. By molecular standards, they are giant—roughly 100 times more massive than even very large conventional polymers and the largest known proteins in biology. Yet despite their enormous size, scientists can precisely control their lengths and organize them into chemically distinct segments with defined dimensions and opposite electrical charges.
That precision also produced an unexpected biological effect. In cell culture studies, the structures enhanced the growth and organization of neurons and increased synapse formation.
The findings introduce a new way to use self-assembly to build highly controlled supramolecular materials with precise arrangements of chemical structures. Ultimately, the work could inform the design of materials for a range of applications, including biomaterials for regenerative medicine.
"These structures represent a breakthrough in materials design, and we already discovered one useful application: their superbioactivity toward neurons, which will bring new opportunities in regenerative medicine," said Northwestern's Samuel I. Stupp, who led the study.
This schematic shows the self-organization of neurons' somas and axons, generating raised regions with a high concentration of somas. The charge-segmented fibers drove this organization, which is reminiscent of the gray and white matter partition in the central nervous system. Credit: Mark Seniw, Center for Regenerative Nanomedicine, Northwestern University
A side-by-side image showing untreated (left) vs. treated mouse cortical neurons. Mouse cortical neurons grown in the presence of charge-segmented supramolecular polymers (right) exhibit extensive neurite outgrowth. Credit: Madison Strong (Stupp Laboratory), Center for Regenerative Nanomedicine, Northwestern University
Supramolecular polymers with precise micrometer-scale length and segmentation. Different colors mark distinct segments in each fibril. Imaged using a confocal microscope. Credit: Michael Dore (Stupp Laboratory), Center for Regenerative Nanomedicine, Northwestern University
Side-by-side image showing untreated (left) vs. treated differentiating human neural progenitor cells. Green indicates taller regions of the cell culture and blue indicates lower regions. Imaged using a confocal microscope. Credit: Madison Strong (Stupp Laboratory), Center for Regenerative Nanomedicine, Northwestern University