Unveiling the benefits of potassium doping on the structural integrity of Li-Mn-rich layered oxides during prolonged cycling by dual-mode EPR spectroscopy.

The oxygen redox process in Li- and Mn-rich layered oxides will inevitably lead to the generation of oxygen vacancies on the surface and their subsequent injection into the bulk lattice, which incurs poor kinetics, capacity decrease, and voltage fading. Herein, this predicament is effectively alleviated by bulk doping of K+, which is intrinsically stable in the lattice to inhibit the generation of oxygen vacancies in the deep delithiated state. More importantly, the benefits of K+ doping on the structural reversibility during prolonged cycling were studied by electron paramagnetic resonance (EPR) spectroscopy in both perpendicular and parallel polarization modes and high-resolution transmission electron microscopy. The results elucidate that the migration of transition-metal ions and oxygen vacancies and the reduction of Mn-ions are mitigated after K+ doping. Consequently, the growth of Li-poor nanovoids in the bulk lattice is greatly diminished and the structural transition from layered to spinel phases is effectively delayed.

Characterization of Acellular Cartilage Matrix-Sodium Alginate Scaffolds in Various Proportions.

The development of three-dimensional (3D) bioprinting technology has provided a new solution to address the shortage of donors, multiple surgeries, and aesthetic concerns in microtia reconstruction surgery. The production of bioinks is the most critical aspect of 3D bioprinting. Acellular cartilage matrix (ACM) and sodium alginate (SA) are commonly used 3D bioprinting materials, and there have been reports of their combined use. However, there is a lack of comprehensive evaluations on ACM-SA scaffolds with different proportions. In this study, bioinks were prepared by mixing different proportions of decellularized rabbit ear cartilage powder and SA and then printed using 3D bioprinting technology and crosslinked with calcium ions to fabricate scaffolds. The physical properties, biocompatibility, and toxicity of ACM-SA scaffolds with different proportions were compared. The adhesion and proliferation of rabbit adipose-derived stem cells on ACM-SA scaffolds of different proportions, as well as the secretion of Collagen Type II, were evaluated under an adipose-derived stem cell chondrogenic induction medium. The following conclusions were drawn: when the proportion of SA in the ACM-SA scaffolds was <30%, the printed structure failed to form. The ACM-SA scaffolds in proportions from 1:9 to 6:4 showed no significant cytotoxicity, among which the 5:5 proportion of ACM-SA scaffold was superior in terms of adhesiveness and promoting cell proliferation and differentiation. Although a higher proportion of SA can provide greater mechanical strength, it also significantly increases the swelling ratio and reduces cell proliferation capabilities. Overall, the 5:5 proportion of ACM-SA scaffold demonstrated a more desirable biological and physical performance.

Peroxide derivatives as SARS-CoV-2 entry inhibitors.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the cause of the ongoing coronavirus disease 2019 (COVID-19) pandemic. Host cell invasion is mediated by the interaction of the viral spike protein (S) with human angiotensin-converting enzyme 2 (ACE2) through the receptor-binding domain (RBD). In this work, bio-layer interferometry (BLI) was used to screen a series of fifty-two peroxides, including aminoperoxides and bridged 1,2,4 - trioxolanes (ozonides), with the aim of identifying small molecules that interfere with the RBD-ACE2 interaction. We found that two compounds, compound 21 and 29, exhibit the activity to inhibit RBD-ACE2. They are further demonstrated to inhibit SARS-CoV-2 cell entry, as shown in pseudovirus assay and experiment with authentic SARS-CoV-2. A comprehensive in silico analysis was carried out to study the physicochemical and pharmacokinetic properties, revealing that both compounds have good physicochemical properties as well as good bioavailability. Our results highlight the potential of small molecules targeting RBD inhibitors as potential therapeutic drugs for COVID-19.

Design, synthesis and antitumor evaluation of novel 1H-indole-2-carboxylic acid derivatives targeting 14-3-3η protein.

In this work, a series of novel 1H-indole-2-carboxylic acid derivatives targeting 14-3-3η protein were designed and synthesized for treatment of liver cancer. After structural optimization for several rounds, C11 displayed a relatively better affinity with 14-3-3η, as well as the best inhibitory activities against several typical human liver cancer cell lines, including Bel-7402, SMMC-7721, SNU-387, Hep G2 and Hep 3B cells. Compound C11 also displayed best inhibitory activity against chemotherapy-resistant Bel-7402/5-Fu cells. Besides, C11 was rather safe against hERG and possessed moderate T1/2 and CL values in liver microsomes. In anti-proliferation, trans-well and cell apoptosis assays, C11 also showed its huge potential as a potent antitumor agent. Then, Western blot assay was conducted, following analyzed by molecular docking, the anti-proliferative mechanisms of this small-molecule inhibitor were revealed. Moreover, C11 was demonstrated to induce G1-S phase cell cycle arrest in liver cancer cells.