The Cytokine TGF-ß Induces Interleukin-31 Expression from Dermal Dendritic Cells to Activate Sensory Neurons and Stimulate Wound Itching.

Cutaneous wound healing is associated with the unpleasant sensation of itching. Here we investigated the mechanisms underlying this type of itch, focusing on the contribution of soluble factors released during healing. We found high amounts of interleukin 31 (IL-31) in skin wound tissue during the peak of itch responses. Il31-/- mice lacked wound-induced itch responses. IL-31 was released by dermal conventional type 2 dendritic cells (cDC2s) recruited to wounds and increased itch sensory neuron sensitivity. Transfer of cDC2s isolated from late-stage wounds into healthy skin was sufficient to induce itching in a manner dependent on IL-31 expression. Addition of the cytokine TGF-ß1, which promotes wound healing, to dermal DCs in vitro was sufficient to induce Il31 expression, and Tgfbr1f/f CD11c-Cre mice exhibited reduced scratching and decreased Il31 expression in wounds in vivo. Thus, cDC2s promote itching during skin would healing via a TGF-ß-IL-31 axis with implications for treatment of wound itching.

High Glucose Intake Exacerbates Autoimmunity through Reactive-Oxygen-Species-Mediated TGF-ß Cytokine Activation.

Diet has been suggested to be a potential environmental risk factor for the increasing incidence of autoimmune diseases, yet the underlying mechanisms remain elusive. Here, we show that high glucose intake exacerbated autoimmunity in mouse models of colitis and experimental autoimmune encephalomyelitis (EAE). We elucidated that high amounts of glucose specifically promoted T helper-17 (Th17) cell differentiation by activating transforming growth factor-ß (TGF-ß) from its latent form through upregulation of reactive oxygen species (ROS) in T cells. We further determined that mitochondrial ROS (mtROS) are key for high glucose-induced TGF-ß activation and Th17 cell generation. We have thus revealed a previously unrecognized mechanism underlying the adverse effects of high glucose intake in the pathogenesis of autoimmunity and inflammation.

The role of epithelial cells in fibrosis: Mechanisms and treatment.

Fibrosis is a pathological process that affects multiple organs and is considered one of the major causes of morbidity and mortality in multiple diseases, resulting in an enormous disease burden. Current studies have focused on fibroblasts and myofibroblasts, which directly lead to imbalance in generation and degradation of extracellular matrix (ECM). In recent years, an increasing number of studies have focused on the role of epithelial cells in fibrosis. In some cases, epithelial cells are first exposed to external physicochemical stimuli that may directly drive collagen accumulation in the mesenchyme. In other cases, the source of stimulation is mainly immune cells and some cytokines, and epithelial cells are similarly altered in the process. In this review, we will focus on the multiple dynamic alterations involved in epithelial cells after injury and during fibrogenesis, discuss the association among them, and summarize some therapies targeting changed epithelial cells. Especially, epithelial mesenchymal transition (EMT) is the key central step, which is closely linked to other biological behaviors. Meanwhile, we think studies on disruption of epithelial barrier, epithelial cell death and altered basal stem cell populations and stemness in fibrosis are not appreciated. We believe that therapies targeted epithelial cells can prevent the progress of fibrosis, but not reverse it. The epithelial cell targeting therapies will provide a wonderful preventive and delaying action.

circMTO1/miR-30c-5p/SOCS3 axis alleviates oral submucous fibrosis through inhibiting fibroblast-myofibroblast transition.

BACKGROUND: circRNAs have been shown to participate in diverse diseases; however, their role in oral submucous fibrosis (OSF), a potentially malignant disorder, remains obscure. Our preliminary experiments detected the expression of circRNA mitochondrial translation optimization 1 homologue (circMTO1) in OSF tissues (n = 20) and normal mucosa tissues (n = 20) collected from Hunan Xiangya Stomatological Hospital, and a significant decrease of circMTO1 expression was showed in OSF tissues. Therefore, we further explored circMTO1 expression in OSF. METHODS: Target molecule expression was detected using RT-qPCR and western blotting. The migration and invasion of buccal mucosal fibroblasts (BMFs) were assessed using wound healing and Transwell assays. The interaction between miR-30c-5p, circMTO1, and SOCS3 was evaluated using dual luciferase, RNA immunoprecipitation (RIP), and RNA pull-down assays. The colocalisation of circMTO1 and miR-30c-5p was observed using fluorescence in situ hybridisation (FISH). RESULTS: circMTO1 and SOCS3 expression decreased, whereas miR-30c-5p expression increased in patients with OSF and arecoline-stimulated BMFs. Overexpression of circMTO1 effectively restrained the fibroblast-myofibroblast transition (FMT), as evidenced by the increase in expression of Coll I, α-SMA, Vimentin, and the weakened migration and invasion functions in BMFs. Mechanistic studies have shown that circMTO1 suppresses FMT by enhancing SOCS3 expression by sponging miR-30c-5p and subsequently inactivating the FAK/PI3K/AKT pathway. FMT induced by SOCS3 silencing was reversed by the FAK inhibitor TAE226 or the PI3K inhibitor LY294002. CONCLUSION: circMTO1/miR-30c-5p/SOCS3 axis regulates FMT in arecoline-treated BMFs via the FAK/PI3K/AKT pathway. Expanding the sample size and in vivo validation could further elucidate their potential as therapeutic targets for OSF.

Prognosis-related molecular subtyping in head and neck squamous cell carcinoma patients based on glycolytic/cholesterogenic gene data.

BACKGROUND: Head and neck squamous cell carcinoma (HNSCC) remains an unmet medical challenge. Metabolic reprogramming is a hallmark of diverse cancers, including HNSCC. METHODS: We investigated the metabolic profile in HNSCC by using The Cancer Genome Atlas (TCGA) (n = 481) and Gene Expression Omnibus (GEO) (n = 97) databases. The metabolic stratification of HNSCC samples was identified by using unsupervised k-means clustering. We analyzed the correlations of the metabolic subtypes in HNSCC with featured genomic alterations and known HNSCC subtypes. We further validated the metabolism-related subtypes based on features of ENO1, PFKFB3, NSDHL and SQLE expression in HNSCC by Immunohistochemistry. In addition, genomic characteristics of tumor metabolism that varied among different cancer types were confirmed. RESULTS: Based on the median expression of coexpressed cholesterogenic and glycolytic genes, HNSCC subtypes were identified, including glycolytic, cholesterogenic, quiescent and mixed subtypes. The quiescent subtype was associated with the longest survival and was distributed in stage I and G1 HNSCC. Mutation analysis of HNSCC genes indicated that TP53 has the highest mutation frequency. The CDKN2A mutation frequency has the most significant differences amongst these four subtypes. There is good overlap between our metabolic subtypes and the HNSCC subtype. CONCLUSION: The four metabolic subtypes were successfully determined in HNSCC. Compared to the quiescent subtype, glycolytic, cholesterogenic and mixed subtypes had significantly worse outcome, which might offer guidelines for developing a novel treatment strategy for HNSCC.

Factors related to microimplant-assisted rapid palatal expansion in teenagers and young adults: A cone-beam computed tomography study.

INTRODUCTION: For patients with maxillary transverse deficiency, selecting an appropriate therapeutic method is important for the treatment effect and prognosis. Our study aimed to explore factors related to microimplant-assisted rapid palatal expansion (MARPE) in teenagers and young adults using cone-beam computed tomography. METHODS: Twenty-five patients who underwent MARPE were included in this retrospective study from February 2014 to June 2019. Midpalatal suture density (MPSD) ratio, midpalatal suture maturation (MPSM), bone effect, dentoalveolar effect, and dental effect in maxillary first molar were evaluated using cone-beam computed tomography. Spearman correlation analysis was used to analyze the correlation between the MPSD ratio, MPSM, age, and the expansion amount generated by MARPE. RESULTS: Twenty-five patients (mean age, 19.84 ± 3.96 years; range, 15-29 years) with maxillary transverse deficiency were analyzed. Age was negatively correlated with bone expansion, alveolar expansion, and alveolar change (all P <0.05). There was a negative correlation between MPSM and nasal cavity variation, bone expansion, and alveolar change (all P <0.05). The bone expansion was negatively correlated with MPSD ratio 3 (r = -0.417; P <0.05) and MPSD ratio 4 (all P <0.05). CONCLUSIONS: Age, MPSM, and MPSD ratio were significantly related to the MARPE effect. Age, MPSM, and MPSD ratio should be considered when choosing MARPE.

Aging and Mesenchymal Stem Cells: Therapeutic Opportunities and Challenges in the Older Group.

With aging, a portion of cells, including mesenchymal stem cells (MSCs), become senescent, and these senescent cells accumulate and promote various age-related diseases. Therefore, the older age group has become a major population for MSC therapy, which is aimed at improving tissue regeneration and function of the aged body. However, the application of MSC therapy is often unsatisfying in the aged group. One reasonable conjecture for this correlation is that aging microenvironment reduces the number and function of MSCs. Cellular senescence also plays an important role in MSC function impairment. Thus, it is necessary to explore the relationship between senescence and MSCs for improving the application of MSCs in the elderly. Here, we present the influence of aging on MSCs and the characteristics and functional changes of senescent MSCs. Furthermore, current therapeutic strategies for improving MSC therapy in the elderly group are also discussed.

Ginsenoside Rh2 inhibits breast cancer cell growth via ERß-TNFα pathway.

Ginsenoside Rh2 is one of rare panaxidiols extracted from Panax ginseng and a potential estrogen receptor ligand that exhibits moderate estrogenic activity. However, the effect of Rh2 on growth inhibition and its underlying molecular mechanism in human breast cells are not fully understood. In this study, we tested cell viability by MTT and colony formation assays. Cell growth and cell cycle were determined to investigate the effect of ginsenoside Rh2 by flow cytometry. The expressions of estrogen receptors (ERs), TNFα, and apoptosis-related proteins were detected by qPCR and western blot analysis. The mechanisms of ERα and ERß action were determined using transfection and inhibitors. Antitumor effect of ginsenoside Rh2 against MCF-7 cells was investigated in xenograft mice. Our results showed that ginsenoside Rh2 induced apoptosis and G1/S phase arrest in MCF-7 cells. Treatment of cells with ginsenoside Rh2 down-regulated protein levels of ERα, and up-regulated mRNA and protein levels of ERß and TNFα. We also found that ginsenoside Rh2-induced TNFα over-expression is through up-regulation of ERß initiated by ginsenoside Rh2. Furthermore, ginsenoside Rh2 induced MCF-7 cell apoptosis via estrogen receptor ß-TNFα pathway in vivo. These results demonstrate that ginsenoside Rh2 promotes TNFα-induced apoptosis and G1/S phase arrest via regulation of ERß.

Changes of the upper airway and bone in microimplant-assisted rapid palatal expansion: A cone-beam computed tomography (CBCT) study.

OBJECTIVE: To evaluate the changes of maxillary expansion and upper airway structure after microimplant assisted rapid palatal expansion (MARPE) using cone-beam computed tomography (CBCT). METHODS: This retrospective study included 19 subjects (15 females and 4 males) aged 15-29 years old (mean, 19.95±4.39 years) with maxillary transverse deficiency treated with MARPE. CBCT was performed at the initial diagnosis and 3 months after MARPE treatment. Measurements were taken to evaluate the amount of total expansion, skeletal expansion, and dental expansion at the maxillary first premolar (P1), second premolar (P2), first molar (M1), second molar (M2) regions and upper airway changes. RESULTS: After MARPE treatment, the maxillary skeletal base expansion, skeletal expansion, alveolar expansion and dental expansion were achieved at the P1, P2, M1, M2 region. The nasopharyngeal volume significantly increased 8.48% after MARPE treatment compared with that before the treatment (P < 0.05). The change of nasal lateral width (NLW) was also significantly different before and after MARPE (P < 0.05). However, there were no statistically significant change in the oropharyngeal, palatopharyngeal, glossopharyngeal and airway total volume (all P > 0.05). CONCLUSIONS: MARPE can produce more transverse bone expansion, relieve maxillary transverse deficiency and improve upper airway ventilation.

Analysis of Senescence-Related Differentiation Potentials and Gene Expression Profiles in Human Dental Pulp Stem Cells.

INTRODUCTION: Dental pulp stem cell (DPSC)-mediated dental pulp regeneration is considered a promising method for the treatment of deep caries with pulpitis. However, mesenchymal stem cell (MSC) senescence is an adverse factor from the perspective of cell-based therapies. In this study, we investigated the characteristics and expression profiles of DPSCs from young and old donors. METHODS: DPSCs from young and old donors were cultured in differentiation medium, and their differentiation potentials were assessed. Long noncoding RNA (LncRNA) microarray assays and a bioinformatic analysis were performed to investigate differences in LncRNA and mRNA expression profiles between DPSCs from young and old donors. RESULTS: We found that DPSCs from young donors exhibited more powerful proliferation ability and greater osteogenic and adipogenic differentiation potentials than DPSCs from old donors. In DPSCs from young donors, numerous LncRNAs were significantly up- (n = 389) or down-regulated (n = 172) compared to DPSCs from old donors. Furthermore, 304 mRNAs were differentially expressed, including 247 up-regulated genes and 57 down-regulated genes in DPSCs from young donors. The bioinformatic analysis identified that several pathways may be associated with DPSC characteristics, such as those involved in the cell cycle and RNA transport, and revealed nuclear transcription factor Y subunit ß, general transcription factor IIB, and nuclear receptor subfamily 3 group C member 1 as core regulatory factors and FR249114, FR299091, and ENST00000450004 as core LncRNAs. CONCLUSIONS: Our results indicated that senescence impaired the proliferation and differentiation potentials of DPSCs and that donor age is an important factor that affects their use for tooth regeneration. We also provide insight into the mechanisms responsible for senescence in DPSCs.

An adaptive immune response driven by mature, antigen-experienced T and B cells within the microenvironment of oral squamous cell carcinoma.

Lymphocyte infiltrates have been observed in the microenvironment of oral cancer; however, little is known about whether the immune response of the lymphocyte infiltrate affects tumor biology. For a deeper understanding of the role of the infiltrating-lymphocytes in oral squamous cell carcinoma (OSCC), we characterized the lymphocyte infiltrate repertoires and defined their features. Immunohistochemistry revealed considerable T and B cell infiltrates and lymphoid follicles with germinal center-like structures within the tumor microenvironment. Flow cytometry demonstrated that populations of antigen-experienced CD4+ and CD8+ cells were present, as well as an enrichment of regulatory T cells; and T cells expressing programmed death-1 (PD-1) and T cell Ig and mucin protein-3 (Tim-3), indicative of exhaustion, within the tumor microenvironment. Characterization of tumor-infiltrating B cells revealed clear evidence of antigen exposure, in that the cardinal features of an antigen-driven B cell response were present, including somatic mutation, clonal expansion, intraclonal variation and isotype switching. Collectively, our results point to an adaptive immune response occurring within the OSCC microenvironment, which may be sustained by the expression of specific antigens in the tumor.

Distal-less homeobox 2 promotes the osteogenic differentiation potential of stem cells from apical papilla.

Dental tissue-derived mesenchymal stem cells (MSCs) are a reliable cell source for dental tissue regeneration. However, the molecular mechanisms underlying the directed differentiation of MSCs remain unclear; thus, their use is limited. The histone demethylase, lysine (K)-specific demethylase 4B (KDM4B), plays critical roles in the osteogenic commitment of MSCs by up-regulating distal-less homeobox 2 (DLX2) expression. The DLX2 gene is highly expressed in dental tissue-derived MSCs but the roles of DLX2 in osteogenesis are unclear. Here, we investigate DLX2 function in stem cells from apical papilla (SCAPs). We found that, in vitro, DLX2 expression was up-regulated in SCAPs by adding BMP4 and by inducing osteogenesis. The knock-down of DLX2 in SCAPs decreased alkaline phosphatase (ALP) activity and mineralization. DLX2 depletion affected the mRNA expression of ALP, bone sialoprotein (BSP) and osteocalcin (OCN) and inhibited SCAP osteogenic differentiation in vitro. Over-expression of DLX2 enhanced ALP activity, mineralization and the expression of ALP, BSP and OCN in vitro. In addition, transplant experiments in nude mice confirmed that SCAP osteogenesis was triggered when DLX2 was activated. Furthermore, DLX2 expression led to the expression of the key transcription factor, osterix (OSX) but not to the expression of runt-related transcription factor 2 (RUNX2). Taken together, these results indicate that DLX2 is stimulated by BMP signaling and enhances SCAP osteogenic differentiation by up-regulating OSX. Thus, the activation of DLX2 signaling might improve tissue regeneration mediated by MSCs of dental origin. These results provide insight into the mechanism underlying the directed differentiation of MSCs of dental origin.

Allogeneic mesenchymal stem cell treatment alleviates experimental and clinical Sjögren syndrome.

Sjögren syndrome (SS) is a systemic autoimmune disease characterized by dry mouth and eyes, and the cellular and molecular mechanisms for its pathogenesis are complex. Here we reveal, for the first time, that bone marrow mesenchymal stem cells in SS-like NOD/Ltj mice and human patients were defective in immunoregulatory functions. Importantly, treatment with mesenchymal stem cells (MSCs) suppressed autoimmunity and restored salivary gland secretory function in both mouse models and SS patients. MSC treatment directed T cells toward Treg and Th2, while suppressing Th17 and Tfh responses, and alleviated disease symptoms. Infused MSCs migrated toward the inflammatory regions in a stromal cell-derived factor-1-dependent manner, as neutralization of stromal cell-derived factor-1 ligand CXCR4 abolished the effectiveness of bone marrow mesenchymal stem cell treatment. Collectively, our study suggests that immunologic regulatory functions of MSCs play an important role in SS pathogenesis, and allogeneic MSC treatment may provide a novel, effective, and safe therapy for patients with SS.

Periodontal ligament stem cells regulate B lymphocyte function via programmed cell death protein 1.

Periodontal ligament stem cells (PDLSCs) have provided novel cell sources for tooth and periodontal tissue regeneration. Allogeneic PDLSCs can reconstruct periodontal ligament tissue that has been damaged by periodontal diseases and regulate T-cell immunity. However, the effect of PDLSCs on B cells remains unknown. Here, we treated periodontitis in a miniature pig model using allogeneic PDLSCs and showed a reduction in humoral immunity in the animals. When cocultured with normal B cells, human PDLSCs (hPDLSCs) had similar effects as bone marrow mesenchymal stem cells in suppressing B cell proliferation, differentiation, and migration, while intriguingly, hPDLSCs increased B cell viability by secreting interleukin-6. Mechanistically, hPDLSCs suppressed B cell activation through cell-to-cell contact mostly mediated by programmed cell death protein 1 and programmed cell death 1 ligand 1. Our data revealed a previously unrecognized function of PDLSCs in regulating humoral immune responses, which may represent a novel therapeutic strategy for immune-related disorders.

MicroRNAs in maxillofacial bone modeling and remodeling: implications for malocclusion development and orthodontic treatment.

Modeling and remodeling are essential processes in the development and refinement of maxillofacial bones. Dysregulated bone modeling during the developmental stage may lead to maxillofacial bone malformations and malocclusion. Bone remodeling under mechanical loading serves as the biological basis for orthodontic treatment. Although previous reviews have indicated the significance of microRNAs (miRNAs) in bone metabolism, their roles in orchestrating maxillofacial bone modeling and remodeling remain unclear. This review aims to discuss the mechanisms by which miRNAs regulate the morphogenesis and development of maxillofacial bones, as well as their implications for maxillofacial malformations and malocclusion. Moreover, miRNAs participating in maxillofacial bone remodeling and their impacts on cell mechanosensing are also summarized. Given the intricate interplay of cells and signaling pathways, exosomal miRNAs emerge as the orchestrators of the modeling and remodeling processes. The diagnostic and therapeutic potentials of miRNAs are also highlighted in this review for future clinical applications.

Topical Application of Nitrate Ameliorates Skin Fibrosis by Regulating ST2+CD4+ T Cells in Systemic Sclerosis Mouse Model.

Systemic sclerosis (SSc) is characterized by intractable multiorgan fibrosis caused by vascular and immune dysfunction. Currently, effective therapeutic options for patients with SSc are limited. Nitrate, an abundant nutrient in the diet, has been demonstrated to be preventative and therapeutic for several diseases. To determine whether nitrate can slow or reverse SSc progression, topical application of nitrate delivered by dissolving microneedles was used to treat a bleomycin (BLM)-induced dermal fibrosis mouse model. In this study, nitrate considerably attenuated dermal thickness, stiffness, and collagen deposition. Bulk RNA sequencing of skin revealed that Cd4 was a key hub gene in SSc nitrate therapy. Additionally, BLM-induced cytokines and chemokines were inhibited by nitrate, and CD4+ T cells infiltration markedly declined. Il4, Il6, Il13, and Tgfb expression in CD4+ T cells isolated from skin biopsies also significantly decreased. Mechanistically, Il1rl1, a type2 immune response inducer, was markedly repressed in isolated CD4+ T cells and dermal tissues after nitrate treatment. Remarkably, compared with wild type mice, mice lacking Il1rl1 showed impaired transcriptional profiles after intradermal BLM injection. Adoptive transfer of ST2+CD4+ T cells promoted bleomycin-induced Rag2-/- mice dermal fibrosis. Collectively, these findings demonstrate that nitrate targeting ST2+CD4+ T cells is an effective therapeutic option for SSc.

Immunomodulatory zinc-based materials for tissue regeneration.

Zinc(Zn)-based materials have contributed greatly to the rapid advancements in tissue engineering. The qualities they possess that make them so beneficial include their excellent biodegradability, biocompatibility, anti-bacterial activity, among and several others. Biomedical materials that act as a foreign body, will inevitably cause host immune response when introduced to the human body. As the osteoimmunology develops, the immunomodulatory characteristics of biomaterials have become an appealing concept to improve implant-tissue interaction and tissue restoration. Recently, Zn-based materials have also displayed immunomodulatory functions, especially macrophage polarization states. It can promote the transformation of M1 macrophages into M2 macrophages to enhance the tissue regeneration and reconstruction. This review covers mainly Zn-based materials and their characteristics, including metallic Zn alloys and Zn ceramics. We highlight the current advancements in the type of immune responses, as well as the mechanisms, that are induced by Zn-based biomaterials, most importantly the regulation of innate immunity and the mechanism of promoting tissue regeneration. To this end, we discuss their applications in biomedicine, and conclude with an outlook on future research challenges.

Administration methods of lipid-based nanoparticle delivery systems for cancer treatment.

As nano medications have developed in the recent four decades, nano-delivery systems have been applied in treating various diseases and are especially common in cancer treatment. Nano-delivery systems could target cancer-associated cells, enhance the accuracy and efficacy of treatment, and reduce systemic side effects. Among the many drugs on nano-carriers, the load system of lipid-based nanoparticles has the brightest prospect due to the high level of biocompatibility, biodegradability, loading capability, and immunogenicity. Previous reviews have comprehensively introduced their effects and progress. However, most of them did not provide great attention to practical applications. This article will focus on different intake methods, which decide the biological process of drugs. This suggests that we can modify lipid-based nano-delivery systems according to how they are capable of prolonging the half-life span and magnifying therapy effects in treating cancer. Besides, we put forth the problems that should be further studied in the future and their probable solutions.

Drug-loaded mucoadhesive microneedle patch for the treatment of oral submucous fibrosis.

Oral submucous fibrosis is a chronic, inflammatory and potentially malignant oral disease. Local delivery of triamcinolone to lesion site is a commonly used therapy. The existing methods for local drug delivery include topical administration and submucosal injection. However, in the wet and dynamic oral microenvironment, these methods have drawbacks such as limited drug delivery efficiency and injection pain. Therefore, it is urgently needed to develop an alternative local drug delivery system with high efficiency and painlessness. Inspired by the structure of band-aid, this study proposed a novel double-layered mucoadhesive microneedle patch for transmucosal drug delivery. The patch consisted of a mucoadhesive silk fibroin/tannic acid top-layer and a silk fibroin microneedle under-layer. When applying the annealing condition for the medium content of ß-sheets of silk fibroin, the microneedles in under-layer displayed both superior morphology and mechanical property. The mechanical strength of per needle (0.071N) was sufficient to penetrate the oral mucosa. Sequentially, the gelation efficiency of silk fibroin and tannic acid in top-layer was maximized as the weight ratio of tannic acid to silk fibroin reached 5:1. Moreover, in vitro results demonstrated the double-layered patch possessed undetectable cytotoxicity. The sustained release of triamcinolone was observed from the double-layered patch for at least 7 days. Furthermore, compared with other commercial buccal patches, the double-layered patch exhibited an enhanced wet adhesion strength of 37.74 kPa. In addition, ex vivo mucosal tissue penetration experiment confirmed that the double-layered patch could reach the lamina propria, ensuring effective drug delivery to the lesion site of oral submucous fibrosis. These results illustrate the promising potential of the drug-loaded mucoadhesive microneedle patch for the treatment of oral submucous fibrosis.