News Release

A new, unique covalent organic framework for use in drug delivery and clean energy

Researchers develop the first 3D COF with unique “scu-c” topology that exhibits efficient gas adsorption and drug delivery capabilities

Peer-Reviewed Publication

Tokyo University of Science

Intriguing structure and drug delivery capability of novel 3D covalent organic framework

image: TUS-84, the novel 3D COF developed at the Tokyo University of Science, exhibits a unique double interpenetrating structure with well-defined voids (left), as well as an extended drug release performance of about 35% after 5 days (right), indicating its potential application in drug delivery. view more 

Credit: Yuichi Negishi from Tokyo University of Science

In our quest for clean energy and sustainable health solutions, advanced materials with unique, customizable properties play a crucial role. Among them, a new generation of porous solids known as three dimensional (3D) covalent organic frameworks (COFs) have generated considerable interest owing to potential applications in catalysis, separation, semiconduction, proton conduction, and biomedicine. The novelty of these materials lies in their synthesis as well as their applications. 3D COFs are porous organic materials developed from linking molecular building blocks with strong covalent bonds into crystalline, extended, net-like reticular three-dimensional structures.

However, synthesis of 3D COFs from pre-designed building units leading to net-like “reticular” arrangement of constituent parts or “network topologies” remains challenging. This is due to the shortage of 3D building units and inadequate reversibility of the linkages between the building units.

Recently, Professor Yuichi Negishi from the Department of Applied Chemistry, Faculty of Science, Tokyo University of Science, Japan, and his colleagues in the Department of Applied Chemistry, Tokyo University of Science, Dr. Saikat Das, Mr. Taishu Sekine, and Ms. Haruna Mabuchi have succeeded for the first time in creating a novel 3D COF unique networked topology. “In this study, we have succeeded for the first time in creating a 3D COF with scu-c topology (network structure) by connecting nodes of a regular plane (4-connected) with nodes of a regular prism (8-connected). This new COF, i.e., TUS-84, has a double interpenetrating structure with well-defined voids,” says Prof. Negishi. The study has been published in  ACS Applied Materials & Interfaces in volume 14 issue 42 of the journal on October 17, 2022.

As a part of the study, the researchers performed a condensation reaction of two organic linkers called DPTB-Me and TAPP with different symmetries, to yield 3D COF with an scu-c net-like arrangement of constituents. The team then conducted powder x-ray diffraction (PXRD) and high-resolution transmission electron microscopy (HRTEM) to analyze the crystal structure and properties of the synthesized 3D COF. The researchers also conducted structural modeling and simulation, which showed great alignment with the observed experimental features while providing further structural insights.

The researchers further demonstrated that the synthesized 3D COF has excellent hydrogen, carbon dioxide, and methane adsorption properties that reinforces its prospects in carbon capture and clean energy applications. As Prof. Negishi notes, “The development of appropriate COFs also facilitates the recovery of metal resources and noble gases, such as argon, in an energy-efficient way. This contributes to the improvement of resource and energy problems.

The icing on the cake for this novel 3D COF is its efficiency in drug delivery applications. The team unveiled TUS-84’s drug delivery capabilities with efficient drug loading and sustained release profiles using ibuprofen, a common nonsteroidal anti-inflammatory drug. TUS-84 showed an extended drug release performance of about 35% after 5 days. This facilitates the delivery of sustained concentrations of drug over a prolonged period. As a result, dose frequency could be reduced, and more consistent control of long-lasting, chronic pain could be possible.

The findings of this study pave the way toward the development of future 3D COFs with unique topologies for applications across a wide range of fields, from medicine to environmental remediation.







About The Tokyo University of Science

Tokyo University of Science (TUS) is a well-known and respected university, and the largest science-specialized private research university in Japan, with four campuses in central Tokyo and its suburbs and in Hokkaido. Established in 1881, the university has continually contributed to Japan's development in science through inculcating the love for science in researchers, technicians, and educators.

With a mission of “Creating science and technology for the harmonious development of nature, human beings, and society", TUS has undertaken a wide range of research from basic to applied science. TUS has embraced a multidisciplinary approach to research and undertaken intensive study in some of today's most vital fields. TUS is a meritocracy where the best in science is recognized and nurtured. It is the only private university in Japan that has produced a Nobel Prize winner and the only private university in Asia to produce Nobel Prize winners within the natural sciences field.



About Professor Yuichi Negishi from Tokyo University of Science

Dr. Yuichi Negishi is a Professor in the Department of Applied Chemistry at Tokyo University of Science, with over 180 publications to his credit. His research expertise includes physical chemistry, cluster chemistry, and nanomaterial chemistry. His notable achievements include The Chemical Society of Japan Award for Young Chemists (Japan Chemical Society, 2008), the Japan Society for Molecular Science Award for Young Scientists (Japan Society for Molecular Science, 2012), Yagami Prize (Keio University, 2017), Distinguished Award 2018 for Novel Materials and Their Synthesis (IUPAC etc., 2018), International Investigator Awards of the Japan Society for Molecular Science (Japan Society for Molecular Science, 2020), and The Chemical Society of Japan Award for Creative Work (Japan Chemical Society, 2021).


Funding information

This study was supported by the Japan Society for the Promotion of Science (JSPS) KAKENHI (grant numbers 20H02698 and 20H02552) and Scientific Research on Innovative Areas “Aquatic Functional Materials” (grant number 22H04562). Funding provided by the Yazaki

Memorial Foundation for Science and Technology and the Ogasawara Foundation for the Promotion of Science and Engineering is also gratefully acknowledged.

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