Water-Soluble Metalated Covalent Organic Nanobelts with Improved Bioavailability for Protein Transportation

Abstract

An available pathway to prepare the ionized covalent organic nanosheets (iCONs) has been proposed by a metal-assisted aqueous-phase exfoliation route from covalent organic frameworks. The soluble and belt-shaped iCONs could immobilize a large quantity of proteins (2.73 mg/mg, BSA/iCONs) and hence serve as transporters to enhance the protein uptake by cancer cells. Meanwhile, their energy-dependent endocytosis pathway via clathrin-coated pits has been proved as well.

Proton-Triggered Fluorescence Switching in Self-Exfoliated Ionic Covalent Organic Nanosheets for Applications in Selective Detection of Anions

“…Among all, recently discovered 2D covalent organic frameworks (COFs) have attracted great attention because of their tailorable structures and affordable functionalizations at the molecular level. − These materials designed via the reticular approach (utilizing kinetically reversible reactions) result in layered structures of highly conjugated nanosheets which are held together through intermolecular forces such as π–π interactions or, in some cases, hydrogen bonding. , These forces play a crucial role in producing highly crystalline, stable COFs with 1D nanochannels for various applications. − However, some adverse effects of these layered structures such as aggregation-caused quenching (ACQ), poor electron mobility, and poor accessibility of deeply buried active sites in the nanochannels lead to the moderate performance of 2D COFs, especially for applications where photoluminescence properties and fast response–recovery are concerned . To counter these negative effects, exfoliation of COFs has been explored via mechanical delamination, chemical modification, , and ultrasonification , to produce the nanosheets of a single layer or a few layers. − However, these techniques also have some disadvantages such as small-scale processing, alteration of the original chemical structure, high energy consumption, and so forth, which limit their widespread use in large scale commercial applications. These issues, however, can be addressed via developing self-exfoliable 2D COFs − to produce smart materials with tuneable photoluminescence properties and well-exposed active sites for desired applications.…”

“…13−15 However, some adverse effects of these layered structures such as aggregation-caused quenching (ACQ), poor electron mobility, and poor accessibility of deeply buried active sites in the nanochannels lead to the moderate performance of 2D COFs, especially for applications where photoluminescence properties and fast response−recovery are concerned. 16 To counter these negative effects, exfoliation of COFs has been explored via mechanical delamination, 17 chemical modification, 18,19 and ultrasonification 20,21 to produce the nanosheets of a single layer or a few layers. 16−24 However, these techniques also have some disadvantages such as small-scale processing, alteration of the original chemical structure, high energy consumption, and so forth, which limit their widespread use in large scale commercial applications.…”

Characteristic Synthesis of a Covalent Organic Framework and Its Application in Multifunctional Tumor Therapy

“…In 2013, Banerjee’s team obtained COF sheets with a thickness between 3 and 10 nm with the mechanical stripping method (Figure b) . In addition, nanoscale TP-Por COFs, TpBD COFs, and NUS 30–32 have also been successfully synthesized by the top-down method. − The bottom-up method has wide applicability and good effects, but requires significant time and energy, and the morphology of the obtained nanosheets is not uniform.…”

Nanoscale covalent organic frameworks as theranostic platforms for oncotherapy: synthesis, functionalization, and applications

“…Due to the low efficiency of the ultrasonic exfoliation method, it is extremely challenging to prepare TpBD COF nanosheets in a large quantity in water. However, macroscopic suspended solids were invisible after dissolving FeCl 3 and ultrasonication for 1 h. 175 Then, the TpBD COF nanosheets with a hydrodynamic diameter of ∼50 nm and thickness of 2.5 nm were successfully obtained with the removal of Fe 3+ by dialysis. Quantitative calculations confirmed that Fe 3+ could coordinate with the β-ketoenamine linkage of TpBD COF, resulting in an increase in the interlayer distance from 3.42 to 9.85 Å; further, the interlayer interaction energy changed from −362 to −19 kJ mol −1 ( Fig.…”