A Counterion-Free Strategy for Chronic Metabolic Acidosis Based on an Orally Administered Gut-Restricted Inorganic Adsorbent.

Chronic metabolic acidosis, arising as a complication of chronic kidney disease (CKD), not only reduces patients' quality of life but also aggravates renal impairment. The only available therapeutic modality, involving intravenous infusion of NaHCO3 , engenders undesirable sodium retention, thereby increasing hemodynamic load and seriously exacerbating the primary disease. This deleterious cascade extends to the development of cardiovascular diseases. Herein, an orally administered, gut-restricted inorganic adsorbent that can effectively alleviate chronic metabolic acidosis without causing any electrolytic derangement or superfluous cardiovascular strain is developed. The genesis of ABC-350 entails the engineering of bismuth subcarbonate via annealing, thereby yielding a partially ß-Bi2 O3 -doped (BiO)2 CO3 biphasic crystalline structure framework enriched with atomic vacancies. ABC-350 can selectively remove chloride ions and protons from the gastrointestinal tract, mimicking the physiological response to gastric acid removal and resulting in increased serum bicarbonate. Owing to its gut-restricted nature, ABC-350 exhibits commendable biosafety, averting undue systemic exposure. In two rat models of metabolic acidosis, ABC-350 emerges not only as a potent mitigator of acidosis but also effects discernible amelioration concerning proximal tubular morphology, interstitial fibrosis, and the incendiary cascades incited by metabolic acidosis. ABC-350, as the translationally relevant material, provides a promising strategy for the treatment of metabolic acidosis.

Electroactive nanofibrous membrane with temperature monitoring for wound healing.

Developing functional dressings for promoting cellular activities and monitoring the healing progress is receiving increasingly widespread attention. In this study, Ag/Zn electrodes were deposited on the surface of a polylactic acid (PLA) nanofibrous membrane which can mimic the extracellular matrix. When wetted by wound exudate, the Ag/Zn electrodes could generate an electric stimulation (ES), promoting the migration of fibroblasts that heal wounds. Moreover, the Ag/Zn@PLA dressing showed excellent antibacterial activity against E. coli (95%) and S. aureus (97%). The study found that the electrostatic (ES) effect and the release of metal ions mainly contribute to the wound healing properties of Ag/Zn@PLA. In vivo mouse models demonstrated that Ag/Zn@PLA could promote wound healing by improving re-epithelialization, collagen deposition, and neovascularization. Additionally, the integrated sensor within the Ag/Zn@PLA dressing can monitor the wound site's temperature in real-time, providing timely information on wound inflammatory reactions. Overall, this work suggests that combining electroactive therapy and wound temperature monitoring may provide a new strategy for designing functional wound dressings.

A small-dataset-trained deep learning framework for identifying atoms on transmission electron microscopy images.

To accurately identify atoms on noisy transmission electron microscope images, a deep learning (DL) approach is employed to estimate the map of probabilities at each pixel for being an atom with element discernment. Thanks to a delicately-designed loss function and the ability to extract features, the proposed DL networks can be trained by a small dataset created from approximately 30 experimental images, each with a size of 256 × 256 pixels2. The accuracy and robustness of the network were verified by resolving the structural defects of graphene and polar structures in PbTiO3/SrTiO3 multilayers from both the general TEM images and their imitated images on which intensities of some pixels lost randomly. Such a network has the potential to identify atoms from very few images of beam-sensitive material and explosive images recorded in a dynamical atomic process. The idea of using a small-dataset-trained DL framework to resolve a specific problem may prove instructive for practical DL applications in various fields.

Template-Assisted Magnetron Sputtering of Cotton Nonwovens for Wound Healing Application.

In the present study, three kinds of functional wound dressings (Zn@Cotton, Ag@Cotton, and Ag/Zn@Cotton) were developed by template-assisted magnetron sputtering of cotton nonwovens. Scanning electron microscopy and energy dispersive spectrometry revealed a very thin, uniform silver oxides and zinc coating on the cotton cellulose microfibers, which was further confirmed by X-ray diffraction pattern, X-ray photoelectron spectrometry, and thermal gravimetric analysis. The physical characteristics such as high swelling ability, moderate air and water vapor permeabilities, good mechanical properties, and excellent flexibility support the suitability of magnetron sputtering cotton nonwovens for wound dressing applications. Moreover, the Ag/Zn@Cotton showed effective antibacterial activities against Escherichia coli and Staphylococcus aureus, which was mainly attributed to the synergistic effect of electrical stimulation and continuous release of Ag+/Zn2+. Meanwhile, benefiting from the low metal coating area percentage (17.54%), the Ag/Zn@Cotton exhibited good cytocompatibility. The in vitro and in vivo test show that Ag/Zn@Cotton can remarkably accelerate the wound healing process, which can be attributed to the enhanced cellular migration by electrical stimulation, strong antibacterial activity, good cytocompatibility, and excellent physical properties. Potentially, template-assisted magnetron sputtering may provide a simple, green, and sustainable alternative for the development of functional wound dressings.

Polydopamine-coated chitosan/calcium pyrophosphate hybrid microflowers as an effective hemostatic agent.

In this study, polydopamine (PDA) coated chitosan/calcium pyrophosphate hybrid microflowers (PDA@CS-CaP) were prepared using a facile approach and evaluated as a hemostatic agent. The surface morphology and elements, chemical groups, porous structure, thermostability, zeta potential, as well as surface wettability were systematically characterized by scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FTIR), N2 adsorption-desorption, thermogravimetry (TGA) and contact angle apparatus. Due to the synergistic effects of the high hydrophilicity (water contact angel nearly 0), chemical activation (the amino and phenol group of PDA), and the flower-like porous hierarchical structure, the prepared PDA@CS-CaP could induce hemocytes and platelets aggregation, promote the blood clotting and achieve bleeding control in vitro and in vivo. Furthermore, the PDA@CS-CaP had no exothermic adverse effects and exhibited better biocompatibility (no cytotoxicity against fibroblasts cells). Thus, the PDA@CS-CaP were expected to be a promising candidate for a safe and promising hemostatic agent because of its porous and hierarchical structures as well as the active PDA coating.