Tag Archives: Yi Cao

PAINT wound-healing ink into your cuts with a 3D-printing pen

This screams tattoo to me but it’s not,

Caption This 3-D printing pen is painting a gel that can help wounds of all shapes heal quickly and effectively. Credit: Adapted from ACS Applied Materials & Interfaces, 2023, DOI: 10.1021/acsami.3c03630

A June 1, 2023 American Chemical Society (ACS) news release (also on EurekAlert), announces a new approach to wound healing,

The body is pretty good at healing itself, though more severe wounds can require bandages or stitches. But researchers publishing in ACS Applied Materials & Interfaces have developed a wound-healing ink that can actively encourage the body to heal by exposing the cut to immune-system vesicles. The ink can be spread into a cut of any shape using a 3D-printing pen, and in mice, the technology nearly completely repaired wounds in just 12 days.

When the skin is cut or torn, the body’s natural “construction crew” kicks in to fix it back up — clearing out any bacterial invaders, regrowing broken blood vessels and eventually forming a scar. Many techniques used to heal wounds can’t do much beyond helping the body do its job better. Bandages or stitches are used to prevent further bleeding, while antibiotics work to prevent complications from infections. But by adding members of the construction crew to a wound-healing treatment or bandage, it could actually accelerate the natural healing process. Specifically, white blood cells or the extracellular vesicles (EVs) secreted from them play important roles in promoting blood vessel formation and reducing inflammation during healing. So, Dan Li, Xianguang Ding and Lianhui Wang wanted to incorporate these EVs into a hydrogel-based wound healing ink that could be painted into cuts of any shape.

The team developed a system called PAINT, or “portable bioactive ink for tissue healing,” using EVs secreted from macrophages combined with sodium alginate. These components were combined in a 3D-printing pen, where they mixed at the pen’s tip and formed a sturdy gel at the site of injury within three minutes. The EVs promoted blood vessel formation and reduced inflammatory markers in human epithelial cells, shifting them into the “proliferative,” or growth, phase of healing. PAINT was also tested on injured mice, where it promoted collagen fiber formation. Mice treated with PAINT had almost healed completely from a large wound after 12 days, compared to mice that didn’t receive the treatment, who were not nearly as far along in the healing process at this time point. The researchers say that this work could help heal a wide variety of cuts quickly and easily, without the need for complex procedures.

The authors acknowledge funding from the Leading-Edge Technology Programme of Jiangsu Natural Science Foundation, the Natural Science Foundation, the Natural Science Foundation of Jiangsu Province, the CAS [Chinese Academy of Sciences] Key Laboratory of Nano-Bio Interface, the Key Laboratory of Nanodevices and Applications, and the Postgraduate Research & Practice Innovation Program of Jiangsu Province.

The American Chemical Society (ACS) is a nonprofit organization chartered by the U.S. Congress. ACS’ mission is to advance the broader chemistry enterprise and its practitioners for the benefit of Earth and all its people. The Society is a global leader in promoting excellence in science education and providing access to chemistry-related information and research through its multiple research solutions, peer-reviewed journals, scientific conferences, eBooks and weekly news periodical Chemical & Engineering News. ACS journals are among the most cited, most trusted and most read within the scientific literature; however, ACS itself does not conduct chemical research. As a leader in scientific information solutions, its CAS division partners with global innovators to accelerate breakthroughs by curating, connecting and analyzing the world’s scientific knowledge. ACS’ main offices are in Washington, D.C., and Columbus, Ohio.

Here’s a link to and a citation for the paper,

Paintable Bioactive Extracellular Vesicle Ink for Wound Healing by Li Li, Zhiyu Wang, Kepeng Wang, Siyuan Fu, Dan Li, Mao Wang, Yi Cao, Houjuan Zhu, Ziyan Li, Lixing Weng, Zhiyang Li, Xianguang Ding, and Lianhui Wang. ACS Appl. Mater. Interfaces 2023, 15, 21, 25427–25436 DOI: https://doi.org/10.1021/acsami.3c03630 Publication Date:May 19, 2023 Copyright © 2023 American Chemical Society

This paper is behind a paywall.

Nano, proteins, and Dr. Hongbin Li: part 2

I had two more questions for Dr. Li concerning the work in his latest published paper, ‘Chameleon Nanomaterial Can Transform from Spring to Shock Absorber, Back Again’ (Nature Nanotechnology, online edition, June 29, 2008)

  1. What stimulus needs to be applied to get the protein to respond as a shock absorber? And, what stimulus for a ‘spring’ response?

Response: spring and shock absorber are two states of the protein materials we constructed. External stimulus, in this case the addition of antibody fragment, is the one to trigger the switch of the protein between the two states.

I wish I could ask Dr. Li more about this. I have a feeling I didn’t word the question clearly enough as I was trying to find out how this would work at the macro level. In fact,  my next and last question was the one where I was trying to find out how this would be applied in materials that I do or can encounter.

  1. You mention a specific application for your work in the Nanowerk article, hydrogels. Apparently they can be used in diapers and breast implants…I’m assuming that this is not what you have in mind. (Sorry, I couldn’t resist. I looked up hydrogels on Wikipedia and, while there were other applications, I thought these two were the funniest when thinking about shock absorbers and springs.) More seriously, do you have another hydrogel example or possibly another application?

Response: there are many more applications than the two you mentioned. Actually the two applications you mentions do not necessarily require hydrogels. Hydrogel can be used in applications ranging from drug delivery, synthetic extracellular matrix to smart materials.

A diaper that springs amuses me and I still don’t see a real life application. I guess I need more specificity, ‘drug delivery’ is too general for me. The Nanowerk article I’m to referring in my question is here.

Dr. Li is an assistant professor in the Department of Chemistry at the University of British Columbia and he is a  Canada Research Chair in Molecular Nanoscience and Protein Engineering. He co-authored the paper with  Chemistry graduate student, Yi Cao.