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Accurate point‐of‐care testing (POC) of low molecular weight heparin (LMWH) can efficiently promote its rational use in the prevention and treatment of thromboembolic diseases but still remain a key challenge. Herein, a peptide‐derived supramolecular self‐assembly system is reported for ultrasensitive and visual detection of LMWH. Two different peptides are designed and modified by gold nanocluster (AuNC) and tetraphenylethene (TPE), respectively, to co‐assemble into nanoparticles, enabling the loading and co‐recognition of LMWH. Owing to two‐wavelength emission from the co‐assemblies at 624 and 460 nm that is highly sensitive to LMWH, such assemblies realize ratio‐type detection of LMWH. The sensitivity of the AuNC‐peptide to LMWH significantly increases when co‐assembling with TPE‐peptide, while that of TPE‐peptide maintains in a high level, enabling a balanced and ultrahigh sensitivity of both two fluorophores. Such self‐assemblies reach an extreme limit of detection of 0.0004 IU mL−1 and realize dramatic fluorescence color change when loading trace concentration of LMWH, which can be simply distinguished by naked‐eye. Thus, by preparing Pep2@AuNC/TPE‐Pep1 test strips the POC testing of LMWH in real thrombus patient samples has achieved. It provides a promising tool for on‐site and real‐time monitoring of anticoagulation therapy to guide LMWH titration into the therapeutic window. [ABSTRACT FROM AUTHOR]

Cell membrane affinity chromatography has been widely applied in membrane protein (MP)-targeted drug screening and interaction analysis. However, in current methods, the MP sources are derived from cell lines or recombinant protein expression, which are time-consuming for cell culture or purification, and also difficult to ensure the purity and consistent orientation of MPs in the chromatographic stationary phase. In this study, a novel in situ synthesis membrane protein affinity chromatography (iSMAC) method was developed utilizing cell-free protein expression (CFE) and covalent immobilized affinity chromatography, which achieved efficient in situ synthesis and unidirectional insertion of MPs into liposomes in the stationary phase. The advantages of iSMAC are: 1) There is no need to culture cells or prepare recombinant proteins; 2) Specific and purified MPs with stable and controllable content can be obtained within 2 h; 3) MPs maintain the transmembrane structure and a consistent orientation in the chromatographic stationary phase; 4) The flexible and personalized construction of cDNAs makes it possible to analyze drug binding sites. iSMAC was successfully applied to screen PDGFR β inhibitors from Salvia miltiorrhiza and Schisandra chinensis . Micro columns prepared by in-situ synthesis maintain satisfactory analysis activity within 72 h. Two new PDGFR β inhibitors, salvianolic acid B and gomisin D, were screened out with K D values of 13.44 and 7.39 μmol/L, respectively. In vitro experiments confirmed that the two compounds decreased α -SMA and collagen Ӏ mRNA levels raised by TGF- β in HSC-T6 cells through regulating the phosphorylation of p38, AKT and ERK. In vivo , Sal B could also attenuate CCl 4 -induced liver fibrosis by downregulating PDGFR β downstream related protein levels. The iSMAC method can be applied to other general MPs, and provides a practical approach for the rapid preparation of MP-immobilized or other biological solid-phase materials., Competing Interests: The authors have no conflicts of interest to declare., (© 2022 Chinese Pharmaceutical Association and Institute of Materia Medica, Chinese Academy of Medical Sciences. Production and hosting by Elsevier B.V.)