Covalent organic
frameworks (COFs) are crystalline polymers with
permanent porosity. They are usually synthesized as micrometer-sized
powders or two-dimensional thin films and membranes for applications
in molecular storage, separation, and catalysis. In this work, we
report a general method to integrate COFs with imine or β-ketoenamine
linkages into three-dimensional (3D)-printing materials. A 3D-printing
template, Pluronic F127, was introduced to coassemble with imine polymers
in an aqueous environment. By limitation of the degree of imine polycondensation
during COF formation, the amorphous imine polymer and F127 form coassembled
3D-printable hydrogels with suitable shear thinning and rapid self-healing
properties. After the removal of F127 followed by an amorphous-to-crystalline
transformation, three β-ketoenamine- and imine-based COFs were
fabricated into 3D monoliths possessing high crystallinity, hierarchical
pores with high surface areas, good structural integrity, and robust
mechanical stability. Moreover, when multiple COF precursor inks were
employed for 3D printing, heterogeneous dual-component COF monoliths
were fabricated with high spatial precision. This method not only
enables the development of COFs with sophisticated 3D macrostructure
but also facilitates the heterogeneous integration of COFs into devices
with interconnected interfaces at the molecular level.
The development of large pore single‐crystalline covalently linked organic frameworks is critical in revealing the detailed structure‐property relationship with substrates. One emergent approach is to photo‐crosslink hydrogen‐bonded molecular crystals. Introducing complementary hydrogen‐bonded carboxylic acid building blocks is promising to construct large pore networks, but these molecules often form interpenetrated networks or non‐porous solids. Herein, we introduced heteromeric carboxylic acid dimers to construct a non‐interpenetrated molecular crystal. Crosslinking this crystal precursor with dithiols afforded a large pore single‐crystalline hydrogen‐bonded crosslinked organic framework HCOF‐101. X‐ray diffraction analysis revealed HCOF‐101 as an interlayer connected hexagonal network, which possesses flexible linkages and large porous channels to host a hydrazone photoswitch. Multicycle Z/E‐isomerization of the hydrazone took place reversibly within HCOF‐101, showcasing the potential use of HCOF‐101 for optical information storage.
Glioblastoma multiforme (GBM) is a malignant tumor caused by complex pathological mechanisms, and is characterized by a high rate of cancer-related mortality and poor patient prognosis. Overgrowth of cancer cells, which results from the inhibition of cell apoptosis and/or the promotion of cell proliferation, leads to the progression of GBM. Therefore, studies into the regulatory mechanisms of cancer cell growth in GBM are required to identify potential therapeutic targets and improve treatment for GBM. In the present study, the role of insulin-like growth factor 1 (IGF1)/IGF1 receptor (IGF1R) signaling in the survival of GBM cells was evaluated. It was observed that IGF1 significantly inhibited the intrinsic and extrinsic pathways of apoptosis (P<0.05), and overexpression of IGF1R significantly promoted the survival of GBM cells (P<0.05). Moreover, both exogenous IGF1 and overexpression of IGF1R promoted the phosphorylation of protein kinase B (AKT), and inhibition of the phosphoinositide 3-kinase (PI3K)/AKT pathway significantly attenuated the inhibitory effects of IGF1/IGF1R on GBM apoptosis (P<0.05). Collectively, these findings indicate that IGF1/IGF1R promotes the survival of GBM cells through activation of the PI3K/AKT pathway. Therefore, inhibition of IGF1/IGF1R may be a viable therapeutic strategy to suppress the progression of GBM.
This communication reports a novel metal-organic framework exhibiting an excellent performance in adsorbing small toxic cationic herbicides, i.e. methyl viologen and diquat, with large adsorption capacities and ultratrace residue levels. To the best of our knowledge, this is the first example of high-performance MOFs trapping toxic cationic herbicides.
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