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Magnesium and its alloys represent promising candidates for biomedical implants due to their biodegradability and mechanical properties, which are similar to natural bone. However, their rapid degradation process characterized by dynamic pH fluctuations and significant hydrogen gas evolution during biocorrosion adversely affects both in vitro and in vivo assessments. While the ISO 10993-5 and 12 standards provide guidelines for evaluating the in vitro biocompatibility of biodegradable materials, they also introduce testing variability conditions that yield inconsistent results. To address these inherent characteristics of Mg alloys, developing improved methods that accurately simulate the physiological environment for in vitro biocompatibility testing is essential. This study introduces two novel extraction approaches for evaluating Mg alloys: a buffered solution utilizing PBS/DMEM with quaternary dilutions and a modified ISO standard protocol employing decuple dilution of conventional unbuffered extracts. The present findings establish that controlled optimization of extraction conditions, specifically buffer composition and dilution parameters, enables reliable in vitro cytotoxicity assessment of Mg alloys, providing a robust methodology that advances the preclinical evaluation of these promising biodegradable materials. [ABSTRACT FROM AUTHOR]

Background: Magnesium alloys degrade rapidly in salt solutions, which limits their use without passivating treatments. AZ31 alloy is particularly promising for implant applications owing to its biodegradability and mechanical properties, necessitating effective corrosion-resistant coatings. Aim: In this study, a self-passivating reactive coating was designed and evaluated for AZ31 magnesium alloy plates using β-tricalcium phosphate (TCP) to enhance corrosion resistance and biocompatibility. Methods: Solutions of TCP, trisodium citrate, magnesium nitrate, hydroxyethyl cellulose (HEC), and sodium chloride were used to dip-coat AZ31 plates. The coated samples were immersed in 3.5 wt% NaCl solution. Phase evolution was analysed using gravimetry, X-ray diffraction (XRD), energy-dispersive X-ray (EDX) spectroscopy, and scanning electron microscopy (SEM). The biological response of the coated samples was evaluated through MTT and resazurin assays. Results: The coating formed a stable TCP/HEC layer that gradually dissolved over two weeks, converting the surface to magnesium hydroxide, magnesium oxychloride, and magnesium phosphate phases. The formation of brucite, responsible for passivation in the long term, was observed. The coating effectively prevented excessive magnesium oxychloride formation and stabilised magnesium hydroxide after one week. Biological characterization indicated that the coating on AZ31 is safe on the Saos-2 and L929 cell lines. Conclusion: The TCP-based coating enhances the corrosion resistance of AZ31 alloy in salt solutions, promoting passivating phases and limiting corrosive products, thereby ameliorating biocompatibility issues. This coating demonstrates substantial potential for extending the longevity and functionality of magnesium alloy implants. [ABSTRACT FROM AUTHOR]

Aging is characterized by an alteration of several physiological processes and biological pathways that leads to an increased susceptibility to age-related diseases and death. Normally, multipotential stem/progenitor cells may contribute to tissue homeostasis, and to minimize the age-depending DNA damage. Scientific research has demonstrated that aging induces several complex changes affecting even the mesenchymal stromal/stem cells (MSCs) ability to self-renew, differentiate, and immunomodulate the human tissues, causing further alterations in the local microenvironment. Cellular senescence can thus be considered as an overall response to several damages. Accordingly, aging seems to create the proper conditions to decrease the tissue's metabolic performance, and the cell-to-cell communication, resulting in a progressive tissue destruction; on the other hand, the MSCs functions appear to be severely reduced. This concise review summarizes the main alterations affecting the MSCs during aging, and it also explains the role of inflammation as a key player in age-related syndromes. The hypothesis is to suggest a parallelism between the thermodynamic concept of "entropy" and biological aging, speculating that both can increase within irreversible systems and both lead toward an irreversible disorder; so, the question is: should we translate aging as disorder? [ABSTRACT FROM AUTHOR]

This editorial discusses the use of dental stem cells in tissue regeneration, highlighting their potential in regenerating various types of human tissues. It emphasizes the importance of stem cells, biomaterials, and growth factors in tissue engineering. The article also discusses the use of bioactive scaffolds and bone morphogenetic proteins in tooth root regeneration. It concludes by suggesting that future research should focus on the safe and predictable use of dental stem cells in surgical therapies and systemic degenerative diseases. Additionally, the article discusses a study that suggests stem cells from human exfoliated deciduous teeth-conditioned medium (SHED-CM) have therapeutic effects on amyotrophic lateral sclerosis (ALS) by promoting the survival and function of motor neurons. This research provides valuable insights into the potential of stem cell therapy for ALS and offers hope for future treatments. [Extracted from the article]

Oral cancer (OC) is one of the most recurrent cancers in the head and neck squamous cancer (SCCHN) category. Recently, the genome-wide association studies (GWAS) have gained growing interest in the scientific community. GWAS have identified several pathways involved in the interactions among general risk factors and genomic variants affecting SCCHN. This systematic overview aims to critically evaluate the latest data reported within the scientific literature. The aim was to investigate the impact of genetic aspects on SCCHN onset and prognosis, involving other clinical and systemic co-factors. PubMed, Google Scholar, and Cancer Genetics Web databases have been systematically investigated for original articles published in the last two years, reporting studies on the main queries addressed in this work. This review also comparatively describes the impact of environmental and pathological co-factors in different types of cancers, clarifying and updating the role of genetic factors in SCCHN onset and development. The main outcomes reported may be helpful to drive clinicians towards their clinical evaluations for the most appropriate therapeutic approach in SCCHN. [ABSTRACT FROM AUTHOR]