In order to deploy detonation nanodiamonds (NDs) in nanomedicine and drug delivery applications, fundamental understanding of their surface chemistry and drug loading capacity is highly desirable. Herein, bone morphogenetic protein 2 (BMP-2) derived peptide with the sequence KIPKASSVPTELSAISTLYLGGC (molecular weight = 2336 g/mol) have been successfully grafted onto NDs using carbodiimide crosslinker chemistry. Initially, functional surface groups of wet- and dry-oxidized NDs were compared using infrared and mass spectroscopy. Dry-oxidized NDs exhibited the highest amount of carboxylic acid derivatives with a surface loading of 0.113 mmol/g after air annealing at 415 °C for 5 h as determined by mass spectroscopy. Compared to wet-oxidation, the dry-oxidation process showed a 1.4-fold increased amount of carbonyl compounds deduced from infrared and mass spectroscopy. Crosslinking of the carboxylic acid derivatives to the primary amines of BMP-2 derived peptide is feasible in the range of 30–96% total surface coverage of NDs. 1:1 and 5:1 ND-peptide ratios were utilized to study the surface loading of NDs using fluorescence spectroscopy. The chemisorption of BMP-2 derived peptide onto NDs reveals superior surface coverage and results in reproducible amounts of tethered bioactive molecules.
Bibliographical noteFunding Information:
We gratefully acknowledge the support through the International Excellence Graduate School on Emerging Materials and Processes Korea (iEGSEMP Korea) in the context of TU Dresden's Institutional Strategy (ZUK 64), funded by the Excellence Initiative of the German Federal and State Governments . This research was supported under the “ Mid-career Researcher Program ” ( NRF-2016R1A2B2014612 ) supervised by the NRF (National Research Foundation) in Republic of Korea.
© 2019 Elsevier Ltd
All Science Journal Classification (ASJC) codes
- Materials Science(all)