Regulatory mechanism of oral mucosal rete peg formation

Human lip vermilion: Physiology and age-related changes

BACKGROUND

The human lip vermilion, also known as the red lip, is important to the quality of life and has long attracted the attention of cosmetic researchers. However, there is limited existing literature on the physiological characteristics and age-related alterations in the human vermilion.

OBJECTIVE

We aim to provide an overview of the physiological characteristics and age-related alterations in the human vermilion.

METHODS

This article is a result of previous research. We conducted a literature search using various academic databases such as Google Scholar, Web of Science, and PubMed. Our findings provided a comprehensive understanding of the physiological characteristics and age-related changes of the human lip vermilion.

RESULTS

The human lip vermilion has a unique structure and physiological characteristics, and during the aging process, a few changes may occur in the human lip vermilion.

CONCLUSION

Understanding the human lip vermilion's physiological characteristics and age-related changes can provide key information for the future innovation of lip vermilion care products. Further investigations are necessary to reach a consensus on the physiological characteristics and age-related alterations in the human vermilion.

Recent trends and perspectives in reconstruction and regeneration of intra/extra-oral wounds using tissue-engineered oral mucosa equivalents

Many conditions, including cancer, trauma, and congenital anomalies, can damage the oral mucosa. Multiple cultures of oral mucosal cells have been used for biocompatibility tests and oral biology studies. In recent decades, the clinical translation of tissue-engineered products has progressed significantly in developing tangible therapies and inspiring advancements in medical science. However, the reconstruction of an intraoral mucosa defect remains a significant challenge. Despite the drawbacks of donor-site morbidity and limited tissue supply, the use of autologous oral mucosa remains the gold standard for oral mucosa reconstruction and repair. Tissue engineering offers a promising solution for repairing and reconstructing oral mucosa tissues. Cell- and scaffold-based tissue engineering approaches have been employed to treat various soft tissue defects, suggesting the potential clinical use of tissue-engineered oral mucosa (TEOMs). In this review, we first cover the recent trends in the reconstruction and regeneration of extra-/intra-oral wounds using TEOMs. Next, we describe the current status and challenges of TEOMs. Finally, future strategic approaches and potential technologies to support the advancement of TEOMs for clinical use are discussed.

Zoledronate/Anti-VEGF Neutralizing Antibody Combination Administration Increases Osteal Macrophages in a Murine Model of MRONJ Stage 0-like Lesions

The pathophysiology, pathogenesis, histopathology, and immunopathology of medication-related osteonecrosis of the jaw (MRONJ) Stage 0 remain unclear, although 50% of MRONJ Stage 0 cases could progress to higher stages. The aim of this study was to investigate the effects of zoledronate (Zol) and anti-vascular endothelial cell growth factor A (VEGFA) neutralizing antibody (Vab) administration on polarization shifting of macrophage subsets in tooth extraction sockets by creating a murine model of MRONJ Stage 0-like lesions. Eight-week-old, female C57BL/6J mice were randomly divided into 4 groups: Zol, Vab, Zol/Vab combination, and vehicle control (VC). Subcutaneous Zol and intraperitoneal Vab administration were performed for 5 weeks with extraction of both maxillary first molars 3 weeks after drug administration. Euthanasia was conducted 2 weeks after tooth extraction. Maxillae, tibiae, femora, tongues, and sera were collected. Structural, histological, immunohistochemical, and biochemical analyses were comprehensively performed. Tooth extraction sites appeared to be completely healed in all groups. However, osseous healing and soft tissue healing of tooth extraction sites were quite different. The Zol/Vab combination significantly induced abnormal epithelial healing, and delayed connective tissue healing due to decreased rete ridge length and thickness of the stratum granulosum and due to decreased collagen production, respectively. Moreover, Zol/Vab significantly increased necrotic bone area with increased numbers of empty lacunae compared with Vab and VC. Most interestingly, Zol/Vab significantly increased the number of CD169⁺ osteal macrophages (osteomacs) in the bone marrow and decreased F4/80+ macrophages, with a slightly increased ratio of F4/80⁺CD38⁺ M1 macrophages compared to VC. These findings are the first to provide new evidence of the involvement of osteal macrophages in the immunopathology of MRONJ Stage 0-like lesions.

Engineering a 3D In Vitro Model of Human Gingival Tissue Equivalent with Genipin/Cytochalasin D

Although three-dimensional (3D) co-culture of gingival keratinocytes and fibroblasts-populated collagen gel can mimic 3D structure of in vivo tissue, the uncontrolled contraction of collagen gel restricts its application in clinical and experimental practices. We here established a stable 3D gingival tissue equivalent (GTE) using hTERT-immortalized gingival fibroblasts (hGFBs)-populated collagen gel directly crosslinked with genipin/cytochalasin D and seeding hTERT-immortalized gingival keratinocytes (TIGKs) on the upper surface for a 2-week air–liquid interface co-culture. MTT assay was used to measure the cell viability of GTEs. GTE size was monitored following culture period, and the contraction was analyzed. Immunohistochemical assay was used to analyze GTE structure. qRT-PCR was conducted to examine the mRNA expression of keratinocyte-specific genes. Fifty µM genipin (G50) or combination (G + C) of G50 and 100 nM cytochalasin D significantly inhibited GTE contraction. Additionally, a higher cell viability appeared in GTEs crosslinked with G50 or G + C. GTEs crosslinked with genipin/cytochalasin D showed a distinct multilayered stratified epithelium that expressed keratinocyte-specific genes similar to native gingiva. Collagen directly crosslinked with G50 or G + C significantly reduced GTE contraction without damaging the epithelium. In summary, the TIGKs and hGFBs can successfully form organotypic multilayered cultures, which can be a valuable tool in the research regarding periodontal disease as well as oral mucosa disease. We conclude that genipin is a promising crosslinker with the ability to reduce collagen contraction while maintaining normal cell function in collagen-based oral tissue engineering.