The receptor for β2GPⅠon membrane of hepatocellular carcinoma cell line SMMC-7721 is annexin Ⅱ

AIM: To evaluate the receptor protein which can specifically bind to β2GPⅠon the membrane of hepatocellular carcinoma (HCC) cell line SMMC-7721, and to study the biological function of the receptor.METHODS: Through β2GPⅠ-affinity chromatography column, the peptid-polysome-mRNA complex, which can specially bind to β2GPⅠ, stayed with the column and was separated from the whole polysome of liver cells, and then eluted and collected. Using cDNA synthesis kit and cDNA PCR kit, the corresponding cDNA was obtained and sequenced. RT-PCR was used to amplify annexinⅡ, and flow cytometry was used to study the competitive binding of annexinⅡ with β2GPⅠto SMMC-7721.RESULTS: A total of 1.1 kb of the cDNA fragment of the specific binding protein of β2GPⅠon liver cell membrane was obtained. The sequence of cDNA shared high homology with human annexinⅡ (98%). AnnexinⅡ was expressed on the membrane of SMMC-7721, and could compete with β2GPⅠfor combining with SMMC-7721.CONCLUSION: The receptor for β2GPⅠon membrane of SMMC-7721 cells is annexinⅡ, which might bridge HBV to infect hepatocytes.

Regulating Actuations and Shapes of Liquid Crystal Elastomers through Combining Dynamic Covalent Bonds with Cooling-Rate-Mediated Control

Realizing multiple locked shapes in pre-oriented liquid crystal elastomers(LCEs)is highly desired for diversifying deformations and enhancing multi-functionality.However,conventional LCEs only deform between two shapes for each actuation cycle upon liquid crystal-isotropic phase transitions induced by external stimuli.Here,we propose to regulate the actuation modes and the locked shapes of a pre-orientated epoxy LCE by combining dynamic covalent bonds with cooling-rate-mediated control.The actuation modes can be adjusted on demand by exchange reactions of dynamic covalent bonds.Derived from the established actuation modes,such as elongation,bending,and spiraling,the epoxy LCE displays varied locked shapes at room temperature under different cooling rates.Various mediums are utilized to control the cooling rate,including water,silicone oil,and copper plates.This approach provides a novel way for regulating the actuation modes and locked shapes of cuttingedge intelligent devices.

Thiol-acrylate Catalyst Enabled Post-Synthesis Fabrication of Liquid Crystal Actuators

Synthesizing orientated liquid crystal elastomers(LCEs)via the two-stage thiol-acrylate Michael addition and photopolymerization(TAMAP)reaction is extensively used.However,excess acrylates,initiators,and strong stimuli are inevitably involved in the second stage crosslinking.Herein,we simplify the strategy through taking advantage of a volatile alkaline(originally added to catalyze the thiol-acrylate addition in the first crosslinking stage).Without excess functional groups,the residual catalyst after annealing is still enough to trigger reactions of dynamic covalent bonds at a relatively mild temperature(80℃)to program the alignment of LCEs.The reversible reaction switches off by itself after this process since the catalyst gradually but totally evaporates upon heating.The obtained soft actuators exhibit robust actuation during repeated deformation(over 1000 times).Many shape-morphing modes can be achieved by rationally designing orientation patterns.This strategy not only facilitates the practical synthesis of LCE actuators,but also balances the intrinsic conflict between stability and reprogrammability of exchangeable LCEs.Moreover,the method of applying volatile catalysts has the potential to be extended to other dynamic covalent bonds(DCBs)applied to crosslinked polymer systems.