Gemini surfactant-like peptide-based nanocages with ß-sheet-enhanced stability and encapsulation efficiency of hydrophobic anticancer drugs.

Peptide-based scaffolds have been widely applied to drug delivery because of their ease and high yields of synthesis, well-defined structure, biocompatibility, diversity, tunability of properties, and molecular recognition abilities. However, the stability of peptide-based nanostructures highly depends on the intermolecular assembling manner, e.g., α-helix based coiled coils, ß-sheet. Inspired by the robust protein fibril structures in amyloidosis, herein we constructed a ß-sheet-forming gemini surfactant-like peptide to self-assemble into nanocages with the help of molecular dynamics simulation. As expected, the experimental results showed that nanocages can be formed with the inner diameter of up to ∼400 nm, which were robust enough even under both transmission electron microscopy and atomic force microscopy, indicating the significant contribution of ß-sheet conformation. The ß-nanocages can load hydrophobic anticancer drugs, e.g., paclitaxel with a very high encapsulation efficiency, which holds great potential for clinic drug delivery due to the improved anticancer effect as compared with paclitaxel alone.

Cooking Delicacy with Ice-Nanobubble Isolation Switches Stewing to 'BBQ'.

The key role of ice in cooking has been neglected. Here, we found negatively charged bulk nanobubbles (BNBs: average size ~60 nm and zeta potential <-20 mV) can be generated in ice-melted water through freeze/thaw-induced cavitation when we studied a local delicacy, 'ice-stewed mutton'. Freeze/thaw-induced BNBs are so robust that they can, in turn, isolate food from water; in this way, they protect and enhance the delicacy by protecting protein structures and preventing flavorful components from being lost. In comparison to cooking with ordinary water, cooking with ice can switch 'stewing' to 'BBQ', which has been proved experimentally via diverse characterization from the nano to micro scale. This study not only provides a novel mechanism for ice-based cooking but also might shed light on the design of potential applications of BNBs in chemical engineering and biomedicine.

Vibrational coupling with O-H stretching increases catalytic efficiency of sucrase in Fabry-Pérot microcavity.

Vibrational strong coupling (VSC) has been reported as a polariton-based method for modulating the rate of biochemical reactions. Herein, we studied how VSC modulates the sucrose hydrolysis. By monitoring the refractive index-induced shift of Fabry-Pérot microcavity, in which the catalytic efficiency of sucrose hydrolysis can be increased at least two times, as VSC was tuned to resonate with the stretching vibration of O-H bonds. This research provides new evidence for applying VSC in life sciences, which holds great promise to improving enzymatic industries.

Water-Soluble and Degradable Gelatin/Polyaniline Assemblies with a High Photothermal Conversion Efficiency for pH-Switchable Precise Photothermal Therapy.

Photothermal therapy (PTT) is regarded as one of the potential techniques to replace surgery in the treatment of tumors. Polyaniline (PANI) shows better biocompatibility than inorganic reagents, which has been widely used in tumor photoacoustic (PA) imaging and PTT. However, the poor water solubility and nonspecific aggregation of PANI nanoparticles severely restricted their biomedical application. In addition, it is difficult to control the photothermal effect just on cancer cells. Herein, we develop tumor pH-responsive PANI-Gel/Cu assemblies, which can achieve targeted and precise ablation of tumors. Due to the high hydrophilicity of gelatin, the PANI-Gel/Cu assemblies show excellent dispersion in physiological solutions and long-term stability. By taking advantage of the self-doping effect between the carboxyl groups in gelatin and the imine part of the PANI skeleton, the photothermal characteristics of PANI-Gel/Cu assemblies can be promoted effectively by the acid tumor microenvironment, and the PA imaging of PANI-Gel/Cu assemblies can also be activated by tumor pH. Consequently, both the PTT enhancement and PA signal amplification can be triggered under a tumor microenvironment, and PANI-Gel/Cu assemblies can be targeted to cancer cells with the RGD sequences in their gelatin skeleton. In vivo imaging-guided PTT to A549 cancer shows precise treatment with little harm to normal cells, and PANI-Gel/Cu assemblies can disassemble into tiny particles (<15 nm) under laser irradiation. This work overcomes the intrinsic limitation of PANI materials, i.e., poor water solubility and nonspecific aggregation, meanwhile providing a pH-active PANI-based platform for precise and effective ablation of cancer.