Oral mucosa: an alternative epidermic cell source to develop autologous dermal-epidermal substitutes from diabetic subjects

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.

Descriptive proteomics of paired human vocal fold and buccal mucosa tissue

The vast majority of voice disorders is associated with changes of the unique, but delicate, human vocal fold mucosa. The ability to develop new effective treatment methods is significantly limited by the physical inaccessibility and the extremely rare occasions under which healthy tissue biopsies can be obtained. Therefore, the interest in laryngological research has shifted to human oral (buccal) mucosa, a similar and more easily available tissue. The harvesting process is less invasive and accompanied with faster healing and less scarring, compared to vocal fold mucosa. Here we report a descriptive proteomic comparison of paired human buccal and vocal fold mucosa by high‐resolution mass spectrometry (CID‐MS/MS). Our study identified a total of 1575 proteins detected within both tissues that are highly consistent in several crucial biological processes, cellular components, and molecular functions. Hence, our proteomic analysis will provide a fundamental resource for the laryngological research community.

Study of tissue engineered vascularised oral mucosa-like structures based on ACVM-0.25% HLC-I scaffold in vitro and in vivo

PURPOSE

To explore the feasibility of constructing tissue-engineered vascularised oral mucosa-like structures with rabbit ACVM-0.25% HLC-I scaffold and human gingival fibroblasts (HGFs), human gingival epithelial cells (HGECs) and vascular endothelial-like cells (VEC-like cells).

METHOD

Haematoxylin and Eosin (H&E) staining, immunohistochemical, immunofluorescence, 5-ethynyl-2'-deoxyuridine (EdU) staining and scanning electron microscope (SEM) were performed to detect the growth status of cells on the scaffold complex. After the scaffold complex implanted into nude mice for 28 days, tissues were harvested to observe the cell viability and morphology by the same method as above. Additionally, biomechanical experiments were used to assess the stability of composite scaffold.

RESULTS

Immunofluorescence and Immunohistochemistry showed positive expression of Vimentin, S100A₄ and CK, and the induced VEC-like cells had the ability to form tubule-like structures. In vitro observation results showed that HGFs, HGECs and VEC-like had good compatibility with ACVM-0.25% HLC-I and could be layered and grow in the scaffold. After implanted, the mice had no immune rejection and no obvious scar repair on the body surface. The biomfechanical test results showed that the composite scaffold has strong stability.

CONCLUSION

The tissue-engineered vascularised complexes constructed by HGFs, HGECs, VEC-like cells and ACVM-0.25% HLC-I has good biocompatibility and considerable strength.

Human keratinocyte-derived microvesicle miRNA-21 promotes skin wound healing in diabetic rats through facilitating fibroblast function and angiogenesis

Skin wound healing is a complex physiological process that maintains the integrity of the skin tissues, involving a variety of distinct cell types and signaling molecules. The specific signaling pathways or extracellular cues that govern the healing processes remain elusive. Microvesicles (MVs) have recently emerged as critical mediators of cell communication by delivery of genetic materials to target cells. In this study, we found the direct delivery of HEKa-MVs expressing miR-21 mimics significantly promoted the healing of skin wound in diabetic rats. In-depth studies showed that MV miR-21 promoted fibroblast migration, differentiation, and contraction, induced a pro-angiogenic process of endothelial cells and mediated a pro-inflammatory response. Mechanically, MV miR-21 might target specific essential effector mRNA in fibroblasts such as MMP-1, MMP-3, TIMP3, and TIMP4 to increase MMPs expression and enzymatic activities. Moreover, MV miR-21 regulated ɑ-SMA and N-cadherin to induce fibroblast-myofibroblast differentiation. MV miR-21 up-regulated the IL-6 and IL-8 expressions and their secretion to amplify the immune response. Furthermore, MV miR-21 down-regulated PTEN and RECK in protein level, and activate MAPK/ERK signaling cascade, thereby promoting fibroblast functions. Thus, our study has provided for the first time the basis for the potential application of HEKa-MVs, and MV miR-21 in particular for wound healing.

New Gene Markers for Metabolic Processes and Homeostasis in Porcine Buccal Pouch Mucosa during Cells Long Term-Cultivation-A Primary Culture Approach

The oral mucosal tissue is a compound structure composed of morphologically and physiologically different cell types. The morphological modification involves genetically determined lifespan, which may be recognized as the balance between cell survival and apoptosis. Although the biochemical processes and pathways in oral mucosa, with special regards to drug transport, delivery, and metabolism, are well known, the cellular physiological homeostasis in this tissue requires further investigation. The porcine buccal pouch mucosal cells (BPMCs) collected from 20 pubertal crossbred Landrace gilts, were used in this study. Immediately after recovery, the oral mucosa was separated micro-surgically, and treated enzymatically. The dispersed cells were transferred into primary in vitro culture systems for a long-term cultivation of 30 days. After each step of in vitro culture (IVC), the cells were collected for isolation of total RNA at 24 h, 7, 15, and 30 days of IVC. While the expression was analyzed for days 7, 15, and 30, the 24th hour was used as a reference for outcome calibration. The gene expression profile was determined using Affymetrix microarray assays and necessary procedures. In results, we observed significant up-regulation of SCARB1, PTGS2, DUSP5, ITGB3, PLK2, CCL2, TGFB1, CCL8, RFC4, LYN, ETS1, REL, LIF, SPP1, and FGER1G genes, belonging to two ontological groups, namely "positive regulation of metabolic process", and "regulation of homeostatic process" at 7 day of IVC as compared to down-regulation at days 15 and 30. These findings suggest that the metabolic processes and homeostatic regulations are much more intense in porcine mucosal cells at day 7 of IVC. Moreover, the increased expression of marker genes, for both of these ontological groups, may suggest the existence of not only "morphological lifespan" during tissue keratinization, but also "physiological checkpoint" dedicated to metabolic processes in oral mucosa. This knowledge may be useful for preclinical experiments with drugs delivery and metabolism in both animals and humans.