DURHAM, N.H.—As is so often the case in pharma and biotech, nature often serves as the source and inspiration for new pharmaceutical compounds and, in the case of University of New Hampshire (UNH) researchers recently, perhaps a new way to get them to where they are needed in the body.
Taking a lead from a color-changing mechanism found in cephalopods—squids, cuttlefish and octopi, for example—researchers at UNH have, the university said in an Oct. 19 news release, “conceived a design for a unique sequential cell-opening mechanism that has many potential applications from drug delivery to color-altering camouflage materials.”
Some of the more obvious uses are clear for “smart materials” that could respond to light, temperature, humidity and other environmental conditions, but the team also sees potential applications for sensors and for materials related to particle release—drug delivery being among the latter uses. Example include biomedical scaffolds, drug-release bandages, drug reservoirs and stents, innovative foldable or deployable devices, smart responsive composites and stretchable soft electronic materials—UNHInnovation, which advocates for, manages and promotes UNH’s intellectual property, has filed a patent for the concept, which is pending.
The research also warranted inclusion as a cover story for Advanced Engineering Materials, which can be found at https://onlinelibrary.wiley.com/doi/10.1002/adem.201700744/abstract.
What the research team did in creating this concept was to modify the chiral geometry of two different cells that were designed to mimic the color-changing organs, or chromatophores, in cephalopods. According to UNH, “When loaded only in one direction, the two different cells (one large and one small) with different attributes, would open sequentially, one after the other.”
“We used two different types of cells, one would open right away and the other would rotate first before opening in the sequence,” said Yaning Li, an assistant professor of mechanical engineering at UNH and one of the authors. “What makes this unique is that if each cell is assigned a different color, you could alter the sequential opening mechanism to create a material that might be dark green when the first cell opened and then change to bright yellow when the second one opened after it. This concept could also be used for particle release, such as two different medicines being released sequentially through a bandage to help address medical issues like wound swelling.”
As a proof-of-concept exercise, the team created a soft “meta-material” that had been discussed in a previous study they authored, and this work reportedly showed that by customizing the chiral geometry at two different levels, the different size cells that were loaded only in one direction did open sequentially.
“The order of the cell opening can also be altered via geometry and material combination to alter the behavior of the cells and increase the number of potential applications,” said Yunyao Jiang, a doctoral candidate in mechanical engineering at UNH and lead author of the current study.
Some of the media coverage of the UNH findings has been more interested in the technology that helped make these cephalopod-based findings possible, a multi-material 3D printer that the UNH researchers used to develop their “hybrid auxetic chiral mechanical metamaterials” and make possible the flexible additive manufacturing process for their experiments.
Also, as one might expect, this isn’t the first time cephalopods have been inspiring for potential therapeutic applications. In 2015, “Cephalopod-Inspired Miniaturized Suction Cups for Smart Medical Skin” was published in Advanced Healthcare Materials, the abstract noting, “Biomimetic miniaturized suction cups (mSCs) are designed for the patient-friendly, dry adhesives of smart medical skin. Both strong van der Waals force and induced negative pressure by the ultrasoft mSCs facilitate tight skin coupling without discomfort or irritations, improve sensitivities of the embedded stretchable electronics for continuous vital sign monitoring, and enable multiple drug reloading without loss of the adhesion.”
