The development of biocompatible self‐healable hydrogel adhesives for skin or wet, stretchable surfaces in air or under water is highly desirable for various biomedical applications ranging from skin patches to bioelectronics. However, it has been proven to be very challenging because most existing hydrogel adhesives are cytotoxic, or poorly adhere to dynamic or stretchable surfaces in wet environments. In this study, multifunctional hydrogel adhesives derived from silk fibroin (SF) and tannic acid (TA) are effectively constructed with high extensibility (i.e., up to 32 000%), real‐time self‐healing capability, underwater adhesivity, water‐sealing ability, biocompatibility, and antibiotic properties. According to all‐atom molecular dynamics simulation studies, the properties of the hydrogel adhesives, especially high extensibility, are mainly attributed to the hydrogen bonds between TA and the SF chains in water, and water and TA molecules can result in loose assemblies with fewer β‐sheets, and more random coils in the SF. Conductivity can also be easily introduced to the adhesive matrix and adjusted when the strain of the adhesives occurs. Considering that it has multiple functions and can be efficiently prepared, the proposed hydrogel adhesives have the potential for future medical applications, such as tissue adhesives and integrated bioelectronics.

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The combination of photodynamic therapy (PDT) and chemotherapy is considered to enhance the antitumor immunity and combat multidrug resistance. Some preclinical studies have reported a positive therapeutic outcome of using ultrasound (US) irradiation to enhance chemotherapy, but the combination of these three modalities has yet to be investigated. On the basis of the discovery of a strong affinity between a photosensitizer sinoporphyrin sodium (DVDMS) and human serum albumin (HSA), a clinically used albumin-paclitaxel (HSA-PTX) nanoparticle is utilized as a “nanoglue” to load a large amount of DVDMS by simple mixing. The five conformations of HSA and DVDMS with highest affinity were calculated using AutoDock Vina. The obtained albumin “nanoglue”-based nanotheranostics, HSA-PTX-DVDMS (HPD), has better fluorescence imaging and PDT performance than free DVDMS, probably due to the reduced quenching of DVDMS after dispersion in albumin. An efficacious tumor-targeting enhancement of chemotherapy by US irradiation is verified in a bilateral subcutaneous 4T1 tumors model. With the aid of US irradiation, the combined PDT and chemotherapy mediated by HPD achieve effective tumor growth inhibition. Overall, this “nanoglue”-based nanotheranostics is composed of several clinically used elements and integrates three clinical modalities with application prospects in clinic.

In this article, we perform a dynamic Monte Carlo simulation study of the helix-coil transition by using a bond-fluctuation lattice model. The results of the simulations are compared with those predicted by the Zimm-Bragg statistical thermodynamic theory with propagation and nucleation parameters determined from simulation data. The Zimm-Bragg theory provides a satisfactory description of the helix-coil transition of a homopolypeptide chain of 32 residues (N = 32). For such a medium-length chain, however, the analytical equation based on a widely-used large-N approximation to the Zimm-Bragg theory is not suitable to predict the average length of helical blocks at low temperatures when helicity is high. We propose an analytical large-eigenvalue (lambda) approximation. The new equation yields a significantly improved agreement on the average helix-block length with the original Zimm-Bragg theory for both medium and long chain lengths in the entire temperature range. Nevertheless, even the original Zimm-Bragg theory does not provide an accurate description of helix-coil transition for longer chains. We assume that the single-residue nucleation of helix formation as suggested in the original Zimm-Bragg model might be responsible for this deviation. A mechanism of nucleation by a short helical block is proposed by us and provides a significantly improved agreement with our simulation data.

Miniaturized spectrometers have attracted much attention due to their capability to detect spectral information within a small size. However, such technology still faces challenges including large-scale preparation and performance repeatability. In this work, we overcome these challenges by demonstrating a microspectrometer constructed with a series of pixelized graded-bandgap perovskite photodetectors fabricated with inkjet printing. High-quality perovskite films with minimal pinholes and large grains are deposited by optimizing printing conditions including substrate temperature and surface modification. The resulting perovskite photodetectors show decent photosensing performance, and the different photodetectors based on perovskite films with different bandgaps exhibit various spectral responsivities with different cutoff wavelength edges. Microspectrometers are then constructed with the array of the pixelized graded-bandgap perovskite photodetectors, and incident spectra are algorithmically reconstructed by combining their output currents. The reconstruction performance of the miniaturized spectrometer is evaluated by comparing the results to the spectral curve measured with a commercial bulky spectrometer, indicating a reliable spectral reconstruction with a resolution of around 10 nm. More significantly, the miniaturized spectrometers are successfully fabricated on polymer substrates, and they demonstrate excellent mechanical flexibility. Therefore, this work provides a flexible miniaturized spectrometer with large-scale fabricability, which is promising for emerging applications including wearable devices, hyperspectral imaging, and internet of things.