Tumor metastasis is one of the big challenges in cancer treatment and is often associated with high patient mortality. Until now, there is an agreement that tumor invasion and metastasis are related to degradation of extracellular matrix (ECM) by enzymes. Inspired by the formation of natural ECM and the in situ self-assembly strategy developed in our group, herein, we in situ constructed an artificial extracellular matrix (AECM) based on transformable Laminin (LN)-mimic peptide 1 (BP-KLVFFK-GGDGR-YIGSR) for inhibition of tumor invasion and metastasis. The peptide 1 was composed of three modules including (i) the hydrophobic bis-pyrene (BP) unit for forming and tracing nanoparticles; (ii) the KLVFF peptide motif that was inclined to form and stabilize fibrous structures through intermolecular hydrogen bonds; and (iii) the Y-type RGD-YIGSR motif, derived from LN conserved sequence, served as ligands to bind cancer cell surfaces. The peptide 1 formed nanoparticles (1-NPs) by the rapid precipitation method, owing to strong hydrophobic interactions of BP. Upon intravenous injection, 1-NPs effectively accumulated in the tumor site due to the enhanced permeability and retention (EPR) effect and/or targeting capability of RGD-YIGSR. The accumulated 1-NPs simultaneously transformed into nanofibers (1-NFs) around the solid tumor and further entwined to form AECM upon binding to receptors on the tumor cell surfaces. The AECM stably existed in the primary tumor site over 72 h, which consequently resulted in efficiently inhibiting the lung metastasis in breast and melanoma tumor models. The inhibition rates in two tumor models were 82.3% and 50.0%, respectively. This in vivo self-assembly strategy could be widely utilized to design effective drug-free biomaterials for inhibiting the tumor invasion and metastasis.

Using broad-spectrum antibiotics for microbial infection may cause flora disequilibrium, drug-resistance, etc., seriously threatening human health. Here, we design a human defensin-6 mimic peptide (HDMP) that inhibits bacterial invasion in vivo through mimicking the mechanisms of human defensin-6 with high efficiency and precision. The HDMP with ligand and self-assembling peptide sequence recognizes bacteria through ligand-receptor interactions and subsequently traps bacteria by an in situ adaptive self-assembly process and resulting nanofibrous networks; these trapped bacteria are unable to invade host cells. In four animal infection models, the infection rate was markedly decreased. Notably, administration of HDMP (5 mg/kg) nanoparticles increased the survival rate of mice with methicillin-resistant S. aureus bacteremia by as much as 100%, even more than that of vancomycin treatment (5 mg/kg, 83.3%)–treated group, the golden standard of antibiotics. This biomimetic peptide shows great potential as a precise and highly efficient antimicrobial agent.

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Owing to the proposal and evolution of DNA origami technique during the past decade, DNA molecules were utilized as building blocks for the precise construction of nanoscale architectures. Benefited from...

The solubility of hydroxyacetic acid in five pure organic solvents and two binary solvent mixtures were experimentally measured from 273.15 K to 313.15 K at atmospheric pressure (p=0.1 MPa) by using a dynamic method. The order of solubility in pure organic solvents is ethanol > isopropanol > n-butanol > acetonitrile > ethyl acetate within the investigated temperature range, except for temperature lower than 278 K where the solubility of HA in ethyl acetate is slightly larger than that in acetonitrile. Furthermore, the solubility data in pure solvents were correlated with the modified Apelblat model, NRTL model, and Wilson model and that in the binary solvents mixtures were fitted to the CNIBS/R-K model and Jouyban-Acree model. Finally, the mixing thermodynamic properties of hydroxyacetic acid in pure and binary solvent systems were calculated and discussed.

Harnessing the programmable nature of DNA origami for controlling structural features in crystalline materials affords opportunities to bring crystal engineering to a remarkable level. However, the challenge of crystallizing a single type of DNA origami unit into varied structural outcomes remains, given the requirement for specific DNA designs for each targeted structure. Here, we show that crystals with distinct equilibrium phases and shapes can be realized using a single DNA origami morphology with an allosteric factor to modulate the binding coordination. As a result, origami crystals undergo phase transitions from a simple cubic lattice to a simple hexagonal (SH) lattice and eventually to a face-centered cubic (FCC) lattice. After selectively removing internal nanoparticles from DNA origami building blocks, the body-centered tetragonal and chalcopyrite lattice are derived from the SH and FCC lattices, respectively, revealing another phase transition involving crystal system conversions. The rich phase space was realized through the de novo synthesis of crystals under varying solution environments, followed by the individual characterizations of the resulting products. Such phase transitions can lead to associated transitions in the shape of the resulting products. Hexagonal prism crystals, crystals characterized by triangular facets, and twinned crystals are observed to form from SH and FCC systems, which have not previously been experimentally realized by DNA origami crystallization. These findings open a promising pathway toward accessing a rich phase space with a single type of building block and wielding other instructions as tools to develop crystalline materials with tunable properties.

In situ target biomolecule analysis is of great significance for real‐time monitoring and regulation of endogenous biomarkers and elementary biomolecules in vivo. Gratifyingly, the rapid evolution of structural DNA nanotechnology during past decades has established an appealing toolbox for biological analysis and medical detection. The modulated self‐assembly and underlying canonical Watson‐Crick base‐pairing rules provide possibilities for accurate controlling of the topologies and functions of obtained nanomaterials. The probes composed of diverse DNA nanostructures and DNA‐nanoparticle complexes can create a confined space, which increases target accessibility and improves probe stability, sensitivity and specificity. In this minireview, we retrospect the research progress of in‐situ biomolecular analysis based on DNA nanostructures for intracellular and in vivo biosensors in confined space. The characteristics of distinct DNA nanomaterials are first introduced, and then the fundamentals of biosensing process of designed DNA nanostructures are emphasized. Moreover, we elucidate our perspective over the challenges of this field and discuss the potential directions of this kind of application‐oriented fabrication technique.

The development and design of the crystallization process strongly depend on accurate solid−liquid equilibrium data. In this paper, the solubility data of amorphous cefmetazole sodium in pure solvents (ethanol, n-propanol, i-propanol, n-butanol, n-amyl alcohol, ethyl acetate, n-butyl acetate, n-hexane, and cyclohexane) and binary solvent mixtures (methanol and ethanol) were measured by using the UV spectroscopic method and gravimetrical method, respectively, at temperatures from 278.15 to 313.15 K. The results show that the solubility data of cefmetazole sodium increase with the increasing temperature in all investigated solvents and decrease with the rise of the mole fraction of ethanol in the binary solvent mixtures. The Apelblat equation was successfully used to correlate the experimental solubility data in pure solvents, and the Apelblat equation, the CNIBS/R-K model, and the Jouyban−Acree model were successfully applied to correlate the solubility data in methanol + ethanol systems. It was found that the correlated data are in good agreement with the experimental data. Additionally, the molecular surface electrostatic potential (MSEP) correlated with the solubility data was also calculated and used to explain the difference of the solubility data of amorphous cefmetazole sodium in various solvents.