Zwitterion‐Functionalized Detonation Nanodiamond with Superior Protein Repulsion and Colloidal Stability in Physiological Media

Abstract

Nanodiamond (ND) is a versatile and promising material for bioapplications. Despite many efforts, agglomeration of nanodiamond and the nonspecific adsorption of proteins on the ND surface when exposed to biofluids remains a major obstacle for biomedical applications. Here, the functionalization of detonation nanodiamond with zwitterionic moieties in combination with tetraethylene glycol (TEG) moieties immobilized by click chemistry to improve the colloidal dispersion in physiological media with strong ion background and for the simultaneous prevention of nonspecific interactions with proteins is reported. Based on five building blocks, a series of ND conjugates is synthesized and their performance is compared in biofluids, such as fetal bovine serum (FBS) and Dulbecco's modified Eagle medium (DMEM). The adsorption of proteins is investigated via dynamic light scattering (DLS) and thermogravimetric analysis. The colloidal stability is tested with DLS monitoring over prolonged periods of time in various ratios of water/FBS/DMEM and at different pH values. The results show that zwitterions efficiently promote the anti‐fouling properties, whereas the TEG linker is essential for the enhanced colloidal stability of the particles.

Efficient Drug Delivery Carrier Surface without Unwanted Adsorption Using Sulfobetaine Zwitterion

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Pyrene‐Based “Turn‐Off” Probe with Broad Detection Range for Cu2+, Pb2+ and Hg2+ Ions

“…The reported sensor combines a previously reported glycol precursor [19] with a rigid arrangement of pyrene moieties. Due to its versatile and extensively investigated properties, pyrene is well suited as a chemical sensor.…”

“…General methods: Azide 1 and alkyne 2 were prepared according to literature procedures. [19,44] All other starting materials were purchased from commercial sources and used as received. The solvents were freshly distilled and dried using standard procedures.…”

Nanodiamond uptake in colon cancer cells: the influence of direction and trypsin-EDTA treatment

“…This process coats diamonds as well but is unavoidable since they are a component of the medium (unless protein repellent coatings are used). 26 Conventionally, cells are first grown and then nanoparticles are administered from the top. We reverse the process and add diamond particles first and then grow cells on top.…”