“Wash-free” method for the synthesis of CD-MOF

The synthesis procedure is very simple and can be reproduced by anyone. γ-CD and the potassium source (KHCO₃, CH₃COOK, KOH, KCl or K₂CO₃) together with a small amount of ethanol were placed in a 250 mL zirconia milling jar containing 30 YTZ® balls. Typically, the molar ratio of mixture is γ-CD : K⁺ : ethanol = 1 : 2 : 0.04; the K⁺/CD ratio can be varied from 0.67 to 8 and the ethanol/CD ratio can be reduced to 0.0085. These were then milled at a rotation rate of 150 rpm for 5 min by using a planetary mill Pulverisette 6 (Fritsch Japan). The products were only dried under atmospheric pressure at 80 °C for 1 h. Since this method only involves milling and drying, the final product can be obtained in 100% solid yield.

 It was demonstrated that the CD-MOF carriers are safe for oral and transpulmonary administration due to their low cytotoxicity to lung, alveolar and small intestinal cells. This method also allows for simultaneous structure formation of the carrier and drug encapsulation within the pore structure by simply adding the drug (e.g. levofloxacin, clotrimazole) during the synthesis of CD-MOFs, thus obtaining high drug content. 

Shuhei Fujita, Kazunori Kadota, Atsushi Koike, Hiromasa Uchiyama, Yuichi Tozuka and Shunsuke Tanaka (2024) “Wash-free” synthesis of cyclodextrin metal–organic frameworks. RSC Mechanochem. Advance Article. https://doi.org/10.1039/D3MR00006K