Wen Kang

Teeth are the hardest organs in the human body. As mineralized structures, they possess a unique microstructure composed of orderly arranged piezoelectric materials such as hydroxyapatite crystals and collagen fibers. Teeth exhibit effective piezoelectric coefficients of approximately 1.2–1.6 pC/N. This inherent property enables teeth to function as natural piezoelectric sensors, converting routine mechanical stresses (e.g., chewing and biting forces, typically ranging from 22.4 to 68.3 kg) into localized electrical signals. This characteristic is of great importance in dentistry and materials science, offering new perspectives into a deeper understanding of the physiological functions and pathological mechanisms of teeth. Despite promising advances, challenges regarding the clinical translation, long-term stability, and biosafety of piezoelectric materials in the oral environment remain unresolved. This review highlights the biological functions of the piezoelectric properties of teeth, discusses recent applications and notable advancements of piezoelectric materials in dentistry, and outlines the challenges and research priorities for future clinical applications.

Coronavirus disease 2019 (COVID-19) caused by acute respiratory syndrome coronavirus 2 (SARS-Cov-2) is still threatening the human life and society throughout the world. For those critically ill patients, mechanical ventilation (MV) is essential to provide life support during treatment. However, both the virus infection and MV disrupt the balance between secretion and elimination of airway mucus and lead to mucus accumulation in the lung. Postmortem examination verified that the lungs in patients died of COVID-19 are indeed filled with sticky mucus, suggesting a great need to improve airway mucus clearance in critically ill COVID-19 patients. Therefore, it may be helpful to comprehensively review the current understanding regarding the changes of biochemical and rheological features of airway mucus associated with the disease, as well as the physiological principles and algorithm to decide airway clearance techniques suitable for the critically ill COVID-19 patients. Based on these considerations, optimized strategies may be developed to eliminate the airway mucus accumulated in the airways of critically ill COVID-19 patients.

Human dental pulp stem cells (hDPSCs), which are characterized by self-renewal capacity and the ability of multilineage differentiation, have gained increased attention in regenerative medicine recently. Histone acetylation modulator proteins (HAMPs) are a protein family that mediates the modification and identification of histone acetylation and participates in various critical cellular processes. Here, we comprehensively surveyed the expression profile of HAMPs during osteoblast differentiation of hDPSCs and found that the HDAC class III pathway was upregulated, whereas the signal transducer and activator of transcription 3 (STAT3) signaling was downregulated during osteogenesis. Further laboratory research demonstrated that Sirtuin-1 (SIRT1), a class III HDAC, was upregulated and STAT3 activation was downregulated during osteogenic differentiation. SIRT1 counteracted the activation of STAT3 to promote osteogenic differentiation of hDPSCs at 7 and 21 days in both Western blot assay and chemical staining, which highlights the promising utility of SIRT1 activators in hDPSCs-based therapies for bone augmentation strategies and provides clinical insights that may lead to the development of osteogenic agents.

A major area of interest in the study of herpes simplex virus type 1 (HSV-1) involves the persistence of the virus within a latent state in neuronal cells