[n]Cycloparaphenylenes as Compatible Fluorophores for MEW

© 2024 EPFL

© 2024 EPFL

Congratulations to our colleague Dr. Biranche Tandon, for his recent publication entitled
"[n]Cycloparaphenylenes as Compatible Fluorophores for Melt Electrowriting"
in the journal "Small", which was a collaboration with our colleagues in the lab of Prof. Dalton at the University of Oregon, USA.

Fluorescent probes are an indispensable tool in the realm of bioimaging technologies, providing valuable insights into the assessment of biomaterial integrity and structural properties. However, incorporating fluorophores into scaffolds made from melt electrowriting (MEW) poses a challenge due to the sustained, elevated temperatures that this processing technique requires. In this context, [n]cycloparaphenylenes ([n]CPPs) serve as excellent fluorophores for MEW processing with the additional benefit of customizable emissions profiles with the same excitation wavelength. Three fluorescent blends are used with distinct [n]CPPs with emission wavelengths of either 466, 494, or 533 nm, identifying 0.01 wt% as the preferred concentration. It is discovered that [n]CPPs disperse well within poly(ε-caprolactone) (PCL) and maintain their fluorescence even after a week of continuous heating at 80 °C. The [n]CPP-PCL blends show no cytotoxicity and support counterstaining with commonly used DAPI (Ex/Em: 359 nm/457 nm), rhodamine- (Ex/Em: 542/565 nm), and fluorescein-tagged (Ex/Em: 490/515 nm) phalloidin stains. Using different color [n]CPP-PCL blends, different MEW fibers are sequentially deposited into a semi-woven scaffold and onto a solution electrospun membrane composed of [8]CPP-PCL as a contrasting substrate for the [10]CPP-PCL MEW fibers. In general, [n]CPPs are potent fluorophores for MEW, providing new imaging options for this technology.

For more details, please visit: https://doi.org/10.1002/smll.202400882


The financial support from the Wu Tsai Human Performance Alliance and the Joe and Clara Tsai Foundation is greatly appreciated. P.D. was supported by the Bradshaw and Holzapfel Research Professorin Transformational Science and Mathematics Fund. H.W.R. and R.J. weresupported by the U.S. National Science Foundation (CHE-2102567)