Multifunctional hyaluronic acid/gelatin methacryloyl core-shell microneedle for comprehensively treating oral mucosal ulcers

Oral ulceration is the most common oral mucosal disease. Oral mucosal ulcers are extremely painful, may interfere with eating and speaking, and potentially complicate systemic symptoms in severe cases. The humid and highly dynamic environment of the oral cavity makes local drug administration for treating oral mucosal ulcers challenging. To overcome these challenges, we designed and prepared a novel dissolving microneedle (MN) patch containing multiple drugs in a core-shell to promote oral ulcer healing. The MNs contained a methacrylate gelatin shell layer of basic fibroblast growth factor (bFGF), a hyaluronic acid (HA) core loaded with dexamethasone (DXMS), and zeolite imidazoline framework-8 (ZIF-8) encapsulated in the HA-based backplane. Progressive degradation of gelatin methacryloyl (GelMA) from the tip of the MN patch in the oral mucosa resulted in sustained bFGF release at the lesion site, significantly promoting cell migration, proliferation, and angiogenesis. Moreover, the rapid release of HA and, subsequently, DXMS inhibited inflammation, and the remaining MN backing after the tip dissolved behaved as a dressing, releasing ZIF-8 for its antimicrobial effects. This novel, multifunctional, transmucosal core-shell MN patch exhibited excellent anti-inflammatory, antimicrobial, and pro-healing effects in vivo and in vitro, suggesting that it can promote oral ulcer healing.

The broadening scope of oral mucositis and oral ulcerative mucosal toxicities of anticancer therapies

Oral mucositis (OM) is a common, highly symptomatic complication of cancer therapy that affects patients' function, quality of life, and ability to tolerate treatment. In certain patients with cancer, OM is associated with increased mortality. Research on the management of OM is ongoing. Oral mucosal toxicities are also reported in targeted and immune checkpoint inhibitor therapies. The objective of this article is to present current knowledge about the epidemiology, pathogenesis, assessment, risk prediction, and current and developing intervention strategies for OM and other ulcerative mucosal toxicities caused by both conventional and evolving forms of cancer therapy.

Electron Spin Resonance Evaluation of Buccal Membrane Fluidity Alterations by Sodium Caprylate and L-Menthol

The ability of sodium caprylate and l-menthol to fluidize phospholipid bilayers composed of lipids simulating the buccal epithelium was investigated using electron spin resonance (ESR) to evaluate the action of these agents as permeation enhancers. 5-Doxyl stearic acid (5-DSA) and 16-doxyl stearic acid (16-DSA) were used as spin labels to identify alterations in membrane fluidity near the polar head groups or inner acyl regions of the lipid bilayer, respectively. The molecular motion of both 5-DSA and 16-DSA showed increased disorder near the polar and inner hydrophobic regions of the bilayer in the presence of sodium caprylate suggesting fluidization in both the regions, which contributes to its permeation enhancing effects. L-menthol decreased the order parameter for 16-DSA, showing membrane fluidization only in the inner acyl regions of the bilayer, which also corresponded to its weaker permeation enhancing effects. The rapid evaluation of changes in fluidity of the bilayer in the presence of potential permeation enhancers using ESR enables improved selection of effective permeation enhancers and enhancer combinations based on their effect on membrane fluidization.

Study of the Possible Alleviated Role of Atorvastatin on Irinotecan-Induced Lingual Mucosal Damage: Histological and Molecular Study

BACKGROUND

Oral mucositis is the most debilitating and troublesome adverse effect of irinotecan (CPT-11) treatment. It adversely affects the patient quality of life. The aim of this work was to study the histological, immunohistochemical, and molecular changes in the oral mucosa by CPT-11 and the possible alleviated role of atorvastatin.

METHODS

Rats were randomly divided into control, CPT-11-treated group, and CPT-11+ atorvastatin-treated group. At the end of the experiment, the anterior two-thirds of the tongue was dissected out and divided into two parts: one part for light microscopic examination and the second for molecular study.

RESULTS

CPT-11-treated group revealed loss of normal mucosal organization, areas of ulceration and inflammation, and loss of architecture of lingual papillae. A significant decrease in immunohistochemical and molecular gene expression of Ki-67 and antiapoptotic Bcl-2 levels was observed. A significant increase in NF-κB immunohistochemical and mRNA gene expression level and a nonsignificant increase in Nrf2 gene expression were detected. Coadministration of atorvastatin showed remarkable improvement in the histopathological picture with a significant increase in Ki-67 and Bcl-2, a significant decrease in NF-κB protein and gene expression, and a significant increase in Nrf2 gene expression.

CONCLUSION

Atorvastatin substantially attenuates CPT-11-induced oral mucositis through the initiation of the antiapoptotic gene, modulation of the inflammatory, and antioxidant gene expression.

Facilitated Buccal Insulin Delivery via Hydrophobic Ion-Pairing Approach: In vitro and ex vivo Evaluation

BACKGROUND

The clinical use of therapeutic peptides has been limited because of their inefficient delivery approaches and, therefore, inadequate delivery to target sites. Buccal administration of therapeutic peptides offers patients a potential alternative to the current invasive routes of administration.

PURPOSE

The aim of the study was to fabricate hydrophobic ion-pairing (HIP)-nanocomplexes (C1 and C2) utilizing anionic bile salts and cationic peptides, and to assess their permeability across TR146 buccal cell layers and porcine buccal tissue.

METHODS

C1 and C2-nanocomplexes were fabricated using the HIP approach. In addition, their physiochemical and morphological attributes, in vitro and ex vivo permeability properties, and qualitative and quantitative cellular uptake were evaluated and compared. The localization of C1 and C2-nanocomplexes in porcine buccal tissue was determined using confocal laser scanning microscopy.

RESULTS

The C1-nanocomplex was the superior nanocarrier and significantly enhanced the transport of insulin across TR146 cell layers and porcine buccal tissue, exhibiting a 3.00- and 51.76-fold increase in permeability coefficient, respectively, when compared with insulin solution (p < 0.01). C1-nanocomplex was more efficient than C2-nanocomplex at facilitating insulin permeability, with a 2.18- and 27.64-fold increase across TR146 cell layers and porcine buccal tissue, respectively. The C1-nanocomplex demonstrated immense uptake and localization of insulin in TR146 cells and porcine buccal tissue, as evidenced by a highly intense fluorescence in TR146 cells, and a great shift of fluorescence intensity towards the inner region of buccal tissue over time. The increase in fluorescence intensity was observed in the order of C1 > C2 > insulin solution.

CONCLUSION

In this study, we highlighted the efficacy of potential nanocarriers in addressing the daunting issues associated with the invasive administration of insulin and indicated a promising strategy for the buccal administration and delivery of this life-saving peptide hormone.

Activity of Experimental Mouthwashes and Gels Containing DNA-RNA and Bioactive Molecules against the Oxidative Stress of Oral Soft Tissues: The Importance of Formulations. A Bioreactor-Based Reconstituted Human Oral Epithelium Model

BACKGROUND

DNA-RNA compounds have shown promising protection against cell oxidative stress. This study aimed to assess the cytotoxicity, protective, or preventive effect of different experimental formulations on oral epithelia's oxidative stress in vitro.

METHODS

Reconstituted human oral epithelia (RHOE) were grown air-lifted in a continuous-flow bioreactor. Mouthwashes and gels containing DNA-RNA compounds and other bioactive molecules were tested on a model of oxidative stress generated by hydrogen peroxide treatment. Epithelia viability was evaluated using a biochemical MTT-based assay and confocal microscopy; structural and ultrastructural morphology was evaluated by light microscopy and TEM.

RESULTS

DNA-RNA showed non-cytotoxic activity and effectively protected against oxidative stress, but did not help in its prevention. Gel formulations did not express adequate activity compared to the mouthwashes. Excipients played a fundamental role in enhancing or even decreasing the bioactive molecules' effect.

CONCLUSION

A mouthwash formulation with hydrolyzed DNA-RNA effectively protected against oxidative stress without additional enhancement by other bioactive molecules. Active compounds, such as hyaluronic acid, β-Glucan, allantoin, bisabolol, ruscogenin, and essential oils, showed a protective effect against oxidative stress, which was not synergistic with the one of DNA-RNA. Incorporation of surfactant agents showed a reduced, yet significant, cytotoxic effect.

A Novel Volume-Stable Collagen Matrix Induces Changes in the Behavior of Primary Human Oral Fibroblasts, Periodontal Ligament, and Endothelial Cells

The aim of the present study was to investigate the influence of a novel volume-stable collagen matrix (vCM) on early wound healing events including cellular migration and adhesion, protein adsorption and release, and the dynamics of the hemostatic system. For this purpose, we utilized transwell migration and crystal violet adhesion assays, ELISAs for quantification of adsorbed and released from the matrix growth factors, and qRT-PCR for quantification of gene expression in cells grown on the matrix. Our results demonstrated that primary human oral fibroblasts, periodontal ligament, and endothelial cells exhibited increased migration toward vCM compared to control cells that migrated in the absence of the matrix. Cellular adhesive properties on vCM were significantly increased compared to controls. Growth factors TGF-β1, PDGF-BB, FGF-2, and GDF-5 were adsorbed on vCM with great efficiency and continuously delivered in the medium after an initial burst release within hours. We observed statistically significant upregulation of genes encoding the antifibrinolytic thrombomodulin, plasminogen activator inhibitor type 1, thrombospondin 1, and thromboplastin, as well as strong downregulation of genes encoding the profibrinolytic tissue plasminogen activator, urokinase-type plasminogen activator, its receptor, and the matrix metalloproteinase 14 in cells grown on vCM. As a general trend, the stimulatory effect of the vCM on the expression of antifibrinolytic genes was synergistically enhanced by TGF-β1, PDGF-BB, or FGF-2, whereas the strong inhibitory effect of the vCM on the expression of profibrinolytic genes was reversed by PDGF-BB, FGF-2, or GDF-5. Taken together, our data strongly support the effect of the novel vCM on fibrin clot stabilization and coagulation/fibrinolysis equilibrium, thus facilitating progression to the next stages of the soft tissue healing process.

Biomonitoring of workers employed in a titanium dioxide production plant: Use of buccal micronucleus cytome assay as noninvasive biomarker to evaluate genotoxic and cytotoxic effects

We aimed to evaluate whether TiO₂ production process induces genotoxic and cytotoxic effects on the first target organ of inhalable particles by a sensitive and noninvasive biomarker of effect. Final aim was to find a useful and suitable tool to assess and manage the risk of TiO₂ occupational exposure. We enrolled 40 workers employed in TiO₂ production, 5 office workers, and 18 external controls. Buccal micronucleus cytome assay (BMCyt assay) was applied because it allows to evaluate micronucleus (MN), nuclear buds (NB), and broken eggs (BE) indicating the presence of chromosomal instability and gene amplification and binucleated cells (BIN), karyolytic cells (KL), and condensed chromatin (CC) indicating cytokinesis defect or arrest, cell death and apoptosis respectively. We characterized the exposure measuring inhalable and respirable particles by personal monitoring. BMCyt-assay showed in exposed workers compared with external controls a higher value of MN frequency (2.57 vs. 0.05‰, p < .001) and MN positivity, evaluated as percentage of subjects with MN frequency higher than a 1.5‰ cut-off value (52.5 vs. 0%). We also found in exposed workers higher frequency of BE + NB (2.41 vs. 0.22‰, p = .002), BIN (9.45 vs. 8.44‰, p = .047) and CC (1.80 vs. 0.21, p = .001) than in controls. Moreover, we found a relationship between personal monitoring results and presence of MN and other cellular anomalies. This study demonstrates induction of genotoxic and cytotoxic effects on buccal cells of workers involved in TiO₂ production, suggesting the suitability of BMCyt assay as tool for risk assessment and management of TiO₂ exposure.

The effect of indocyanine green-mediated photodynamic therapy in healing of experimentally induced oral mucosal traumatic ulcer in rat

Photodynamic therapy (PDT) is a promising approach for the healing of ulcerative lesions. This study aimed to investigate the effect of PDT using indocyanine green (ICG) in the healing of the experimentally induced oral mucosal traumatic ulcer in rat. Sixty adult male Sprague-Dawley rats were recruited in this experimental study. The ulceration was surgically made in the left cheek mucosa, and the rats were randomly assigned into four equal groups (n = 15). Oral ulcers in groups 1 and 2 were treated with the sterile saline solution (0.9%) and ICG (1 mg/ml). In group 3, laser irradiation was applied using the 810 nm diode laser in the continuous-wave mode for 30 s (light dose: 55 J/cm2, power: 300 mW, spot size: 4.5 mm). Following the topical application of ICG (1 mg/ml) in group 4, laser irradiation was performed in the same way as the previous group. After 24 h, treatments were repeated once more in all groups. The healing process was histopathologically assessed at the 3rd, 7th, and 14th days after ulceration. Wound healing was significantly accelerated in the ICG-mediated PDT group in comparison to the control group at all sampling time points (p < 0.005). However, the other groups displayed a similar healing rate (p > 0.05). Data suggest that ICG-mediated PDT has the potential to accelerate wound healing and prevent clinical infection in oral mucosal traumatic ulcers. However, further studies are required to confirm whether our results can be generalized to other wounds.

System, Method and Software for Calculation of a Cannabis Drug Efficiency Index for the Reduction of Inflammation

There are many varieties of Cannabis sativa that differ from each other by composition of cannabinoids, terpenes and other molecules. The medicinal properties of these cultivars are often very different, with some being more efficient than others. This report describes the development of a method and software for the analysis of the efficiency of various cannabis extracts to detect the anti-inflammatory properties of the various cannabis extracts. The method uses high-throughput gene expression profiling data but can potentially use other omics data as well. According to the signaling pathway topology, the gene expression profiles are convoluted into the signaling pathway activities using a signaling pathway impact analysis (SPIA) method. The method was tested by inducing inflammation in human 3D epithelial tissues, including intestine, oral and skin, and then exposing these tissues to various extracts and then performing transcriptome analysis. The analysis showed a different efficiency of the various extracts in restoring the transcriptome changes to the pre-inflammation state, thus allowing to calculate a different cannabis drug efficiency index (CDEI).

Synthetic peptide SVVYGLR upregulates cell motility and facilitates oral mucosal wound healing

Osteopontin-derived SVVYGLR (SV) 7-amino-acid sequence is a multifunctional and synthetic SV peptide implicated in angiogenesis, production of collagen III, and fibroblast differentiation into myofibroblasts. This study investigated the effect of the SV peptide on mucosal wound healing activity. Normal human-derived gingival fibroblasts (NHGF) and human oral mucosa keratinocytes (HOMK) were used for in vitro experiments. In addition, an oral punch wound was prepared at the buccal mucosa in male rats aged 11 weeks, and we evaluated the effect of local injection of SV peptide on wound healing. The synthetic SV peptide showed no influence on the proliferation and adhesion properties of NHGF and HOMK, but it enhanced the cell motility and migration activities. TGF-β1 receptor inhibitor, SB431542 or SB505124, substantially suppressed the SV peptide-induced migration activity, suggesting an involvement of TGF-β1 receptor activation. Furthermore, SV peptide accelerated the healing process of an in vivo oral wound model, compared with control groups. Further immunohistological staining of wound tissue revealed that an increase in capillary growth and the greater number of fibroblasts and myofibroblasts that migrated into the wound area might contribute to the facilitation of the healing process produced by the SV peptide. The SV peptide has beneficial effects on oral wound healing through enhancement of the earlier phase consisting of angiogenesis and remodeling with granulation tissue. The synthetic SV peptide can be a useful treatment option, particularly for intractable mucosal wounds caused by trauma or surgery for progressive lesions such as oral cancer.

In search of preventive strategies: novel high-CBD Cannabis sativa extracts modulate ACE2 expression in COVID-19 gateway tissues

With the current COVID-19 pandemic, caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), there is an urgent need for new therapies and prevention strategies that can help curtail disease spread and reduce mortality. The inhibition of viral entry and thus spread is a plausible therapeutic avenue. SARS-CoV-2 uses receptor-mediated entry into a human host via the angiotensin-converting enzyme 2 (ACE2), which is expressed in lung tissue as well as the oral and nasal mucosa, kidney, testes and gastrointestinal tract. The modulation of ACE2 levels in these gateway tissues may be an effective strategy for decreasing disease susceptibility. Cannabis sativa, especially those high in the anti-inflammatory cannabinoid cannabidiol (CBD), has been found to alter gene expression and inflammation and harbour anti-cancer and anti-inflammatory properties. However, its effects on ACE2 expression remain unknown. Working under a Health Canada research license, we developed over 800 new C. sativa cultivars and hypothesized that high-CBD C. sativa extracts may be used to down-regulate ACE2 expression in target COVID-19 tissues. Using artificial 3D human models of oral, airway and intestinal tissues, we identified 13 high-CBD C. sativa extracts that decrease ACE2 protein levels. Some C. sativa extracts down-regulate serine protease TMPRSS2, another critical protein required for SARS-CoV-2 entry into host cells. While our most effective extracts require further large-scale validation, our study is important for future analyses of the effects of medical cannabis on COVID-19. The extracts of our most successful novel high-CBD C. sativa lines, pending further investigation, may become a useful and safe addition to the prevention/treatment of COVID-19 as an adjunct therapy.

Effects of Sucrose Palmitate on the Physico-Chemical and Mucoadhesive Properties of Buccal Films

In our current research, sucrose palmitate (SP) was applied as a possible permeation enhancer for buccal use. This route of administration is a novelty as there is no literature on the use of SP in buccal mucoadhesive films. Films containing SP were prepared at different temperatures, with different concentrations of SP and different lengths of hydroxypropyl methylcellulose (HPMC) chains. The mechanical, structural, and in vitro mucoadhesive properties of films containing SP were investigated. Tensile strength and mucoadhesive force were measured with a device and software developed in our Institute. Positron annihilation lifetime spectroscopy (PALS) and X-ray powder diffractometry (XRPD) were applied for the structure analysis of the films. Mucoadhesive work was calculated in two ways: from the measured contact angle and compared with direct mucoadhesive work, which measured mucoadhesive force, which is direct mucoadhesion work. These results correlate linearly with a correlation coefficient of 0.98. It is also novel because it is a new method for the determination of mucoadhesive work.

Potential effects of noxious chemical-containing fine particulate matter on oral health through reactive oxygen species-mediated oxidative stress: Promising clues

Nowadays, air pollution which is dominated by fine particulate matter with aerodynamic diameter less than or equal to 2.5 µm resulting from rapid industrialization and urbanization combined with population explosion has become more and more severe problem to mankind and the whole planet because of its diversity of deleterious effects. The latest data estimated that exposure to fine particulate matter, or PM2.5, contributes to approximately 4 million deaths worldwide due to cardiopulmonary conditions such as heart disease and stroke, respiratory infections, chronic lung disease and lung cancer. During recent years, there has been growing concern about the adverse effects of this global threat on oral health which is one of key components of general health and quality of life. Although a few studies have reported such possible association, the findings are still far from conclusion. Moreover, the underlying mechanisms remain unclear. To our knowledge, the analysis of literature regarding this scope has yet been published. Thus, current work systematically assesses existing evidences on the potential association between exposure to PM2.5 and the development of various oral diseases as well as figures out the plausible paradigm of PM2.5-induced damages in the oral cavity through its toxic chemical constituents along with its ability to induce oxidative stress via reactive oxygen species production. This might partially provide the clues for new research ideas and progression in the field of oral health.

Oral Submucous Fibrosis: A Review on Biomarkers, Pathogenic Mechanisms, and Treatments

Oral submucous fibrosis (OSF) is a collagen deposition disorder that affects a patient’s oral function and quality of life. It may also potentially transform into malignancy. This review summarizes the risk factors, pathogenic mechanisms, and treatments of OSF based on clinical and bio-molecular evidence. Betel nut chewing is a major risk factor that causes OSF in Asia. However, no direct evidence of arecoline-induced carcinogenesis has been found in animal models. Despite identification of numerous biomarkers of OSF lesions and conducting trials with different drug combinations, clinicians still adopt conservative treatments that primarily focus on relieving the symptoms of OSF. Treatments focus on reducing inflammation and improving mouth opening to improve a patient’s quality of life. In conclusion, high-quality clinical studies are needed to aid clinicians in developing and applying molecular biomarkers as well as standard treatment guidelines.

Enhancement of Simvastatin ex vivo Permeation from Mucoadhesive Buccal Films Loaded with Dual Drug Release Carriers

BACKGROUND

Simvastatin (SMV), a hypocholesterolemic agent, suffers from very low bioavailability due to its poor aqueous solubility and extensive first-pass metabolism.

METHODS

Two SMV carrier systems, namely, polymeric drug inclusion complex (IC) and mixed micelles (MM) nanoparticles, were developed and loaded into mucoadhesive buccal films to enhance SMV bioavailability. The two carrier systems were characterized and their permeation across human oral epithelial cells (OEC) was studied. The effect of IC to MM ratio (X1) and the mucoadhesive polymer concentration (X2) on the cumulative percent of drug released, elongation percent and the mucoadhesive strength, from the prepared mucoadhesive films, were optimized. Ex vivo permeation across bovine mucosal tissue was investigated. The permeation parameters for the in vitro and ex vivo release data were calculated.

RESULTS

Complexation of SMV with hydroxypropyl beta-cyclodextrin (HP β-CD) was superior to all other polymers as revealed by the equilibrium saturation solubility, stability constant, complexation efficiency and thermodynamic potential. SMV-HP β-CD IC was utilized to develop a saturated polymeric drug solution. Both carrier systems showed enhanced permeation across OEC when compared to pure drug. X1 and X2 were significantly affecting the characteristics of the prepared films. The optimized mucoadhesive buccal film formulation loaded with SMV IC and drug MM nanoparticles demonstrated superior ex vivo permeation when compared to the corresponding pure drug buccal film, and the calculated permeation parameters confirmed this finding.

CONCLUSION

Mucoadhesive buccal films containing SMV IC and drug MM can be used to improve drug bioavailability; however, additional pharmacokinetic and pharmacodynamic studies are required.

Patient-derived oral mucosa organoids as an in vitro model for methotrexate induced toxicity in pediatric acute lymphoblastic leukemia

We have recently established a protocol to grow wildtype human oral mucosa organoids. These three-dimensional structures can be maintained in culture long-term, do not require immortalization, and recapitulate the multilayered composition of the epithelial lining of the oral mucosa. Here, we validate the use of this model to study the effect of Leucovorin (LV) on Methotrexate (MTX)-induced toxicity. MTX is a chemotherapeutic agent used in the treatment of pediatric acute lymphoblastic leukemia. Although effective, the use of MTX often results in severe side-effects, including oral mucositis, which is characterized by epithelial cell death. Here, we show that organoids are sensitive to MTX, and that the addition of LV reduces MTX toxicity, in both a concentration- and timing-dependent manner. Additionally, we show that a 24 hour ‘pretreatment’ with LV reduces MTX-induced cell death, suggesting that such a pretreatment could decrease mucositis in patients. Taken together, we provide the first in vitro model to study the effect of MTX on wildtype oral mucosa cells. Our findings underscore the relevance of the clinically applied LV regimen and highlight the potential of this model to further optimize modifications in dosing and timing of Leucovorin on oral mucosa cells.

Comparison of Genotoxic Effect in Buccal Exfoliated Cells between Cigarette and Waterpipe Smokers

BACKGROUND/AIM

Cytogenetic biomarkers such as micronuclei (MN) are used for the evaluation of exposure to carcinogens and genotoxic effects in oral epithelial cells. Tobacco is one of the strongest carcinogens responsible for the development of cancer in oral mucosa. The aim of this study was to compare the genotoxic effect of waterpipe smoking with that of cigarette smoking.

METHODS

This case-control study was performed on 30 waterpipe smokers, 30 cigarette smokers, and 30 nonsmokers. Buccal exfoliated cells were prepared using cytobrushes and stained with the Papanicolaou technique. The cytologic slides were examined under a light microscope for counting the number of MN and the number of cells with MN per 1,000 epithelial cells.

RESULTS

The mean number ± standard deviation (SD) of MN in waterpipe smokers, cigarette smokers, and nonsmokers was 7.55 ± 5.530, 4.95 ± 5.633, and 2.00 ± 2.406, respectively. The mean number ± SD of cells with MN in waterpipe smokers, cigarette smokers, and nonsmokers was 6.20 ± 4.830, 3.50 ± 3.832, and 1.45 ± 1.701, respectively. Numbers of cells with MN differed significantly between waterpipe smokers and cigarette smokers (p = 0.04) and between waterpipe smokers and nonsmokers (p < 0.001). Numbers of MN differed significantly between waterpipe smokers and nonsmokers (p < 0.001). Numbers of MN did not differ significantly between waterpipe smokers and cigarette smokers (p = 0.10). Numbers of MN and of cells with MN did not differ significantly between cigarette smokers and nonsmokers (p = 0.06 and p = 0.052, respectively).

CONCLUSIONS

Waterpipe smoking is associated with a significantly higher frequency of MN, and it seems that waterpipe smoking has a greater genotoxic effect than cigarette smoking.

Inhibitory Effects of a Reengineered Anthrax Toxin on Canine Oral Mucosal Melanomas

Canine oral mucosal melanomas (OMM) are the most common oral malignancy in dogs and few treatments are available. Thus, new treatment modalities are needed for this disease. Bacillus anthracis (anthrax) toxin has been reengineered to target tumor cells that express urokinase plasminogen activator (uPA) and metalloproteinases (MMP-2), and has shown antineoplastic effects both, in vitro and in vivo. This study aimed to evaluate the effects of a reengineered anthrax toxin on canine OMM. Five dogs bearing OMM without lung metastasis were included in the clinical study. Tumor tissue was analyzed by immunohistochemistry for expression of uPA, uPA receptor, MMP-2, MT1-MMP and TIMP-2. Animals received either three or six intratumoral injections of the reengineered anthrax toxin prior to surgical tumor excision. OMM samples from the five dogs were positive for all antibodies. After intratumoral treatment, all dogs showed stable disease according to the canine Response Evaluation Criteria in Solid Tumors (cRECIST), and tumors had decreased bleeding. Histopathology has shown necrosis of tumor cells and blood vessel walls after treatment. No significant systemic side effects were noted. In conclusion, the reengineered anthrax toxin exerted inhibitory effects when administered intratumorally, and systemic administration of this toxin is a promising therapy for canine OMM.

A Review of Zinc-L-Carnosine and Its Positive Effects on Oral Mucositis, Taste Disorders, and Gastrointestinal Disorders

Zinc-L-carnosine (ZnC), also called polaprezinc known as PepZin GI™, is a chelated compound that contains L-carnosine and zinc. It is a relatively new molecule and has been associated with multiple health benefits. There are several studies that support ZnC’s benefits in restoring the gastric lining, healing other parts of the gastrointestinal (GI) tract, improving taste disorders, improving GI disorders, and enhancing skin and liver. Oral mucositis is a common complication of cytotoxic radiotherapy and/or chemotherapy. It occurs in almost every person with head and neck cancer who receive radiotherapy. It is often overlooked because it is not considered life threatening. However, mucositis often leads to a decreased quality of life and cessation of treatment, ultimately decreasing positive outcomes. Therefore, solutions to address it should be considered. The primary mechanisms of action are thought to be localized and related to ZnC’s anti-inflammatory and antioxidant functions. Therefore, the purpose of this review is to discuss the research related to ZnC and to explore its benefits, especially in the management of conditions related to damaged epithelial cells, such as oral mucositis. Evidence supports the safety and efficacy of ZnC for the maintenance, prevention, and treatment of the mucosal lining and other epithelial tissues. The research supports its use for gastric ulcers (approved in Japan) and conditions of the upper GI and suggests other applications, particularly for oral mucositis.

Daily Time of Radiation Treatment Is Associated with Subsequent Oral Mucositis Severity during Radiotherapy in Head and Neck Cancer Patients

BACKGROUND

Limited treatment options are available for oral mucositis, a common, debilitating complication of cancer therapy. We examined the association between daily delivery time of radiotherapy and the severity of oral mucositis in patients with head and neck cancer.

METHODS

We used electronic medical records of 190 patients with head and neck squamous cell carcinoma who completed radiotherapy, with or without concurrent chemotherapy, at Roswell Park Comprehensive Cancer Center (Buffalo, NY) between 2015 and 2017. Throughout a 7-week treatment course, patient mouth and throat soreness (MTS) was self-reported weekly using a validated oral mucositis questionnaire, with responses 0 (no) to 4 (extreme). Average treatment times from day 1 until the day before each mucositis survey were categorized into seven groups. Multivariable-adjusted marginal average scores (LSmeans) were estimated for the repeated- and maximum-MTS, using a linear-mixed model and generalized-linear model, respectively.

RESULTS

Radiation treatment time was significantly associated with oral mucositis severity using both repeated-MTS (n = 1,156; P = 0.02) and maximum-MTS (n = 190; P = 0.04), with consistent patterns. The severity was lowest for patients treated during 8:30 to <9:30 am (LSmeans for maximum-MTS = 2.24; SE = 0.15), increased at later treatment times and peaked at early afternoon (11:30 am to <3:00 pm, LSmeans = 2.66-2.71; SEs = 0.16/0.17), and then decreased substantially after 3 pm.

CONCLUSIONS

We report a significant association between radiation treatment time and oral mucositis severity in patients with head and neck cancer.

IMPACT

Although additional studies are needed, these data suggest a potential simple treatment time solution to limit severity of oral mucositis during radiotherapy without increasing cost.

Understanding retention and metabolization of aroma compounds using an in vitro model of oral mucosa

The mechanism leading to aroma persistence during eating is not fully described. This study aims at better understanding the role of the oral mucosa in this phenomenon. Release of 14 volatile compounds from different chemical classes was studied after exposure to in vitro models of oral mucosa, at equilibrium by Gas-Chromatography-Flame Ionization Detection (GC-FID) and in dynamic conditions by Proton Transfer Reaction- Mass Spectrometry (PTR-MS). Measurements at equilibrium showed that mucosal hydration reduced the release of only two compounds, pentan-2-one and linalool (p < 0.05), and suggested that cells could metabolize aroma compounds from different chemical families (penta-2,3-dione, trans-2-hexen-1-al, ethyl hexanoate, nonan- and decan-2-one). Dynamic analyses for pentan-2-one and octan-2-one evidenced that the constituents of the mucosal pellicle influenced release kinetics differently depending on molecule hydrophobicity. This work suggests that mucosal cells can metabolize aroma compounds and that non-covalent interactions occur between aroma compounds and oral mucosa depending on aroma chemical structure.

Bisphosphonate's Effect on Tongue Mucosa: An Experimental Electron Microscopy Study

BACKGROUND AND OBJECTIVES

Bisphosphonates (BPs) are selective inhibitors of osteoclasts, used for the treatment of bone disorders. The objective of this study is to investigate the possible effects of BPs on the tongue's mucosa.

MATERIALS AND METHODS

Specimens of the tongue of 20 female 12-month old Wistar rats were taken. Ten were used as control group, while in the remaining alendronate (Fosamax, Merck) was administered per os from 13 weeks. Observation of the harvested samples was made by Transmission Electron Microscopy (TEM).

RESULTS

In the experimental group, focal alterations were observed to various extent in all specimens. The basement membrane was intact. Furthermore, an increase at the intercellular space was observed, predominantly at the middle layer, and the desmosomes were disorganized. In the lamina propria focal edema was observed.

CONCLUSIONS

Investigation on the effect of BPs on the tongue's mucosa through TEM hasn't been documented in the past. According to our results, BPs seem to cause mild mucosal lesions on the tongue.

Long-term Stabilization of Aqueous Doxycycline Formulations, in Mucoadhesive Hydrogels for Treatment of Oral Mucosal Conditions

BACKGROUND

The main aim of this work was to develop stable (>2 years) doxycycline formulation, at clinically relevant concentrations and using clinically relevant formulation. Doxycycline has a MMP- inhibitory effects that is important for the treatment of various oral mucosal conditions. Therefore, protecting doxycycline from degradation in aqueous formulation requires halting or prevention of oxidation and epimerisation of the active compound.

METHODS

Stabilizing excipients were intuitively put together to enhance the stability as a cumulative effort. A total of 30 hydrogels were compared with different types and concentrations of stability enhancing excipients, pH, storage temperatures (4, 25 and 40°C) and mucoadhesive polymers. The duration of the study was from day 1 and up to 58 months. The gelation temperature was adjusted below the actual body temperature. The complexation efficiency between the doxycycline and HPβCD was studied using the DSC, FTIR and XRPD.

RESULTS

The majority of formulations at 4°C were highly stable by the end of 58 months and their stabilities were improved at all 3 temperatures.

CONCLUSION

In conclusion, it is possible to prevent doxycycline from both oxidation and epimerization in an aqueous formulation, for up to 5 years.

HIV-1 proteins gp120 and tat induce the epithelial-mesenchymal transition in oral and genital mucosal epithelial cells

The oral, cervical, and genital mucosa, covered by stratified squamous epithelia with polarized organization and strong tight and adherens junctions, play a critical role in preventing transmission of viral pathogens, including human immunodeficiency virus (HIV). HIV-1 interaction with mucosal epithelial cells may depolarize epithelia and disrupt their tight and adherens junctions; however, the molecular mechanism of HIV-induced epithelial disruption has not been completely understood. We showed that prolonged interaction of cell-free HIV-1 virions, and viral envelope and transactivator proteins gp120 and tat, respectively, with tonsil, cervical, and foreskin epithelial cells induces an epithelial-mesenchymal transition (EMT). EMT is an epigenetic process leading to the disruption of mucosal epithelia and allowing the paracellular spread of viral and other pathogens. Interaction of cell-free virions and gp120 and tat proteins with epithelial cells substantially reduced E-cadherin expression and activated vimentin and N-cadherin expression, which are well-known mesenchymal markers. HIV gp120- and tat-induced EMT was mediated by SMAD2 phosphorylation and activation of transcription factors Slug, Snail, Twist1 and ZEB1. Activation of TGF-β and MAPK signaling by gp120, tat, and cell-free HIV virions revealed the critical roles of these signaling pathways in EMT induction. gp120- and tat-induced EMT cells were highly migratory via collagen-coated membranes, which is one of the main features of mesenchymal cells. Inhibitors of TGF-β1 and MAPK signaling reduced HIV-induced EMT, suggesting that inactivation of these signaling pathways may restore the normal barrier function of mucosal epithelia.

Red-Emissive Guanylated Polyene-Functionalized Carbon Dots Arm Oral Epithelia against Invasive Fungal Infections

Oral candidiasis as a highly prevalent and recurrent infection in medically compromised individuals is mainly caused by the opportunistic fungal pathogen Candida albicans. This epithelial infection, if not controlled effectively, can progress to life-threatening systemic conditions and complications. The efficacy of current frontline antifungals is limited due to their poor bioavailability and systemic toxicity. As such, an efficient intervention is essential for controlling disease progression and recurrence. Herein, a theranostic nanoplatform (CD-Gu⁺-AmB) was developed to track the penetration of antifungals and perturb the invasion of C. albicans at oral epithelial tissues, via decorating the homemade red-emissive carbon dots (CD) with positively charged guanidine groups (Gu⁺) followed by conjugation with antifungal polyene (amphotericin B, AmB) in a reacting site-controllable manner. The generated CD-Gu⁺-AmB favorably gathered within the Candida cells and exhibited potent antifungal effects in both planktonic and biofilm forms. It selectively accumulated in the nuclei of human oral keratinocytes and exhibited undetectable toxicity to the host cells. Moreover, we reported for the first time the penetration and exfoliation profiles of CD in a three-dimensional organotypic model of human oral epithelial tissues, demonstrating that the extra- and intracellular accumulation of CD-Gu⁺-AmB effectively resisted the invasion of C. albicans by forming a "shielding" layer throughout the entire tissue. This study establishes a multifunctional CD-based theranostic nanoplatform functioning as a traceable and topically applied antifungal to arm oral epithelia, thereby shedding light on early intervention of mucosal candidiasis for oral and general health.

Biomimetic hydrogel for rapid and scar-free healing of skin wounds inspired by the healing process of oral mucosa

Inspired by the wound healing characteristics of the oral mucosa, a biomimetic hydrogel was prepared to realize the rapid and scar-free healing of skin wounds. Through monitoring the healing process of injured oral mucosa, we find out that the combination of high, rapid and sequential expression of some growth factors and the sterile-moist microenvironment are crucial for re-epithelialization and precise control of the inflammation process. On the base of our findings, a hydrogel loaded with several functional compounds was prepared to achieve a comprehensive simulation of the oral mucosal trauma microenvironment for skin wound healing. After 7 days treatment, the skin wound area of the treated group was only about 20% of that of the untreated group, and the proportion of collagen type III and type I in the treated group was much higher than that of the untreated group, suggesting lighter scar hyperplasia. The comprehensive treatment strategy of sequential expression of growth factors in combination with maintaining of a sterile and humid environment is expected to have great application prospect in the field of chronic trauma repair and cosmetic surgery. STATEMENT OF SIGNIFICANCE: Long healing time and scar hyperplasia during wound healing have been a serious problem in the past decades of wound healing research. Oral cavity wound healing occurs in an environment that sustains ongoing physical trauma and is rich in bacteria. Despite this, injuries to the mucosal surface often heal faster than cutaneous wounds and leave less noticeable scars. Therefore, in recent years, many scholars have begun to study the healing mechanism of oral mucosa, which supports a new inspiration for the study of skin wound repair: whether the injured skin can achieve a rapid scar-free healing effect similar to oral mucosa? Imitating the biological process of oral mucosa wound healing would be a promising therapeutic strategy in wound healing. Therefore, inspired by the wound healing characteristics of the oral mucosa, a biomimetic gel was prepared to realize the rapid and scar-free healing of skin wounds. Through monitoring the healing process of injured oral mucosa, the combination of high, rapid and sequential expression of some growth factors and sterile-moist microenvironment was crucial for re-epithelialization and precise control of the inflammation process. The comprehensive treatment strategy of sequential expression of growth factors in combination with maintance of a sterile and humid environment implies its potential use in the field of chronic trauma repair and cosmetic surgery.

Epidermal growth factor attenuates lingual papillae lesions in a rat model of sialoadenectomy

Salivary epidermal growth factor (EGF) plays an important role in the maintenance of the oral and gastro-esophageal mucosa. Sialoadenectomy delays healing of oral wounds and affects lingual papillae. In this work, we aimed to determine the effect of EGF deficiency induced by sialoadenectomy and evaluate the effect of exogenous EGF administration on the lingual papillae and taste buds in rats. Thirty male adult Wistar albino rats were equally divided into 3 groups; sham-operated control group, sialoadenectomy group and group of sialoadenectomy + EGF. EGF was given 8 weeks after sialoadenectomy in a dose of 1 μg /ml/day in drinking water for 2 weeks. The anterior two-thirds of the tongue was dissected and cut longitudinally into two halves; one half for light microscope and the other for electron microscope examinations. Saliva and blood were collected to determine salivary and plasma EGF. Our results revealed that sialoadenectomy significantly reduced plasma and saliva levels of EGF which resulted in severe disruption of the architecture of lingual papillae. These changes were effectively improved by the exogenous EGF administration. In conclusion, EGF supplementation reversed the effects of sialoadenectomy and restored almost normal architecture of lingual papillae and taste buds.

[Mouth and medication]

Mouth and medication. Medication holds a prominent place for better comfort and increased life expectancy. Adverse effects and drug interactions are frequently observed and reported. Many of the drug-related complications - unrelated to excessive pharmacological activity - which we describe occur in the mouth.

N-Acetylcysteine Rinse for Thick Secretion and Mucositis of Head and Neck Chemoradiotherapy (Alliance MC13C2): A Double-Blind Randomized Clinical Trial

OBJECTIVE

To determine whether N-acetylcysteine rinse was safe and could improve thickened secretions and dry mouth during and after radiotherapy.

PATIENTS AND METHODS

We designed a prospective pilot double-blind, placebo-controlled randomized clinical trial (Alliance MC13C2). Adult patients (age ≥18 years) were enrolled if they underwent chemoradiotherapy (≥60 Gy). Patients initiated testing rinse within 3 days of starting radiotherapy. With swish-and-spit, they received 10% N-acetylcysteine (2500 mg daily) or placebo rinse solution 5 times daily during radiotherapy and 2 weeks postradiotherapy. The primary aim was to evaluate N-acetylcysteine in improvement of saliva viscosity with the Groningen Radiotherapy-Induced Xerostomia questionnaire. Secondary aims included evaluating xerostomia improvement by the same questionnaire and with the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire-Head and Neck-35 Questions survey and adverse-event profiles. The type I error rate was 20%.

RESULTS

Thirty-two patients undergoing chemoradiotherapy were enrolled. Baseline characteristics were balanced for placebo (n=17) and N-acetylcysteine (n=15). N-acetylcysteine was better for improving sticky saliva (area under curve, P=.12). Scores of multiple secondary end points favored N-acetylcysteine, including sticky saliva daytime (P=.04), daytime and total xerostomia (both P=.02), pain (P=.18), and trouble with social eating (P=.15). Repeated measures models confirmed the findings. Taste was a major dissatisifer for N-acetylcysteine rinse; however, both testing rinses were safe and well tolerated overall.

CONCLUSION

Our pilot data showed that N-acetylcysteine rinse was safe and provided strong evidence of potential efficacy for improving thickened saliva and xerostomia by patient-reported outcome. A confirmatory phase 3 trial is required.

TRIAL REGISTRATION

clinicaltrials.gov Identifier: NCT02123511.

Putting out the fire - Efficacy of common beverages in reducing oral burn from capsaicin

Capsaicin is classically considered an irritant, due to the warming and burning sensations it elicits. Widespread consumption of chilis suggests many individuals enjoy this burn, but these sensations can be overwhelming if the burn is too intense. While substantial folklore exists on the ability of specific beverages to mitigate capsaicin burn, quantitative data to support these claims are generally lacking. Here, we systematically tested various beverages for their ability to reduce oral burn following consumption of capsaicin in tomato juice. Participants (n = 72, 42 women, 30 men) rated the burn of 30 mL of spicy tomato juice on a general Labeled Magnitude Scale (gLMS) immediately after swallowing, and again every 10 s for 2 min. On 7 of 8 trials, a test beverage (40 mL) was consumed after tomato juice was swallowed, including: skim milk, whole milk, seltzer water, Cherry Kool-Aid, non-alcoholic beer, cola, and water. Participants also answered questions regarding intake frequency and liking of spicy food. Initial burn of tomato juice alone was rated below "strong" but above "moderate" on a gLMS and continued to decay over the 2 min to a mean just above "weak". All beverages significantly reduced the burn of the tomato juice. To quantify efficacy over time, area under the curve (AUC) values were calculated, and the largest reductions in burn were observed for whole milk, skim milk, and Kool-Aid. More work is needed to determine the mechanism(s) by which these beverages reduce burn (i.e., partitioning due to fat, binding by protein, or sucrose analgesia). Present data suggest milk is the best choice to mitigate burn, regardless of fat context, suggesting the presence of protein may be more relevant than lipid content.

Relationships of Long-Term Smoking and Moist Snuff Consumption With a DNA Methylation Age Relevant Smoking Index: An Analysis in Buccal Cells

INTRODUCTION

Currently, there is no widely accepted, non-self-report measure that simultaneously reflects smoking behaviors and is molecularly informative of general disease processes. Recently, researchers developed a smoking index (SI) using nucleated blood cells and a multi-tissue DNA methylation-based predictor of chronological age and disease (DNA methylation age [DNAm-age]). To better understand the utility of this novel SI in readily accessible cell types, we used buccal cell DNA methylation to examine SI relationships with long-term tobacco smoking and moist snuff consumption.

METHODS

We used a publicly available dataset composed of buccal cell DNA methylation values from 120 middle-aged men (40 long-term smokers, 40 moist snuff consumers, and 40 nonsmokers). DNAm-age (353-CpGs) and SI (66-CpGs) were calculated using CpG sites measured using the Illumina HumanMethylation450 BeadChip. We estimated associations of tobacco consumption habits with both SI and DNAm-age using linear regression models adjusted for chronological age, race, and methylation technical covariates.

RESULTS

In fully adjusted models with nonsmokers as the reference, smoking (β = 1.08, 95% CI = 0.82 to 1.33, p < .0001) but not snuff consumption (β = .06, 95% CI = -0.19 to 0.32, p = .63) was significantly associated with SI. SI was an excellent predictor of smoking versus nonsmoking (area under the curve = 0.92, 95% CI = 0.85 to 0.98). Four DNAm-age CpGs were differentially methylated between smokers and nonsmokers including cg14992253 [EIF3I], which has been previously shown to be differentially methylated with exposure to long-term fine-particle air pollution (PM2.5).

CONCLUSIONS

The 66-CpG SI appears to be a useful tool for measuring smoking-specific behaviors in buccal cells. Still, further research is needed to broadly confirm our findings and SI relationships with DNAm-age.

IMPLICATIONS

Our findings demonstrate that this 66-CpG blood-derived SI can reflect long-term tobacco smoking, but not long-term snuff consumption, in buccal cells. This evidence will be useful as the field works to identify an accurate non-self-report smoking biomarker that can be measured in an easily accessible tissue. Future research efforts should focus on (1) optimizing the relationship of the SI with DNAm-age so that the metric can maximize its utility as a tool for understanding general disease processes, and (2) determining normal values for the SI CpGs so that the measure is not as study sample specific.

Results of buccal micronucleus cytome assay in pesticide-exposed and non-exposed group

Since many different pesticides have been used occupationally, there have been inconsistent results regarding DNA damages among greenhouse workers. Thus, the aim of the study is to evaluate DNA damages, cell death, and chromosomal instability by using the buccal micronucleus cytome (BMcyt) assay in greenhouse workers and to compare those with a non-exposed group. The BMcyt assay was applied to the exfoliated buccal cell samples collected from 66 pesticide-exposed and 50 non-exposed individuals. We evaluated the frequency of micronucleus (MN), nuclear bud (NBUD), binucleated (BN) cells, and karyolitic (KL), pyknotic (PY), and karyorrhectic (KH) cells. The results showed that the MN, BN, PY, and KH frequencies of the pesticide-exposed group were significantly higher than those of the controls (P ˂ 0.05, P ˂ 0.05, P ˂ 0.01, and P ˂ 0.05, respectively). We observed that the MN, BN, PY, and KH frequencies in the autumn were statistically different compared with those in the control group (P = 0.037 for MN, P = 0.001 for BN, P = 0.016 for PY, and P = 0.033 for KH). The same comparison was done in the spring for the control, and there was a statistically significant difference for MN (P = 0.046) and PY (P = 0.014). We can conclude that pesticide exposure in greenhouse workers was one of the factors that altered DNA damages, cell death, and chromosomal instability in oral mucosa cells.

Environmental boron exposure does not induce DNA damage in lymphocytes and buccal cells of females: DNA damage in lymphocytes and buccal cells of boron exposed females

Boron (B) compounds are essential for plants and animals and beneficial for humans in nutritional amounts. I animals and humans increasing evidence have shown beneficial effects on B compounds on nutrition and on antioxidant status. The genotoxic effects of environmental B exposure in women living in boron-rich and boron-poor areas was examined in this study. For this purpose, the DNA damage in the lymphocytes and buccal cells of females were assessed by Comet and micronucleus (MN) assays respectively. No significant difference was observed in the DNA damage of the lymphocytes of B exposed groups of female volunteers in Comet assay. Even buccal micronucleus (MN) frequency observed in the high exposure group was significantly lower than the low exposure group (p < 0.05). The results of this study came to the same conclusions of the previous studies that boron does not induce DNA damage even under extreme exposure conditions.

Cytotoxic and genotoxic effects in mechanics occupationally exposed to diesel engine exhaust

Diesel engine exhaust (DEE), which is the product of diesel combustion, is considered carcinogenic in humans. It comprises toxic gases, polycyclic aromatic hydrocarbons (PAHs) and particulate matter which can reach the pulmonary parenchyma and trigger various diseases, including cancer. The aim of the present study was to evaluate the potential cytotoxic and genotoxic effects of DEE exposure on peripheral blood and buccal epithelial cells in mechanics occupationally exposed to DEE. We recruited 120 exposed mechanics and 100 non-exposed control individuals. Significant differences were observed between the two groups in terms of percentage of tail DNA and damage index (DI) in the alkaline comet assay; levels of biomarkers by cytokinesis-block micronucleus cytome (CBMN-Cyt) assay; frequency of micronucleus (MN), nucleoplasmic bridge (NPB), nuclear bud (NBUD) and apoptotic cells (APOP) and levels of biomarkers for micronucleus, karyorrhexis (KRX), karyolysis (KRL) and condensed chromatin (CC) by the buccal micronucleus cytome (BM-Cyt) assay. A significant and positive correlation was found between the frequency of MN in lymphocytes and buccal cells in the exposed group. Also, there was a significant correlation between age and percentage of tail DNA and DI in the comet assay, APOP and MN in the CBMN-Cyt assay and NBUD and MN in the BM-Cyt assay. Additionally, we found a positive and significant correlation of MN frequency in lymphocytes and buccal cells and age and MN frequency in lymphocytes with the time of service (years). Regarding lifestyle-related factors, a significant correlation was observed between meat and vitamin consumption and NBUD formation on CBMN-Cyt and between meat consumption and MN formation on CBMN-Cyt. Of the BM-Cyt biomarkers, there was a correlation between alcohol consumption and NBUD formation and between binucleated cell (BN), pyknosis (PYC), CC and KRL occurrence and family cancer history. These results are the first data in Colombia on the cytotoxic and genotoxic effects induced by continuous exposure to DEE and thus showed the usefulness of biomarkers of the comet, CBMN-Cyt and BM-Cyt assays for human biomonitoring and evaluation of cancer risk in the exposed populations.

Chemotherapy-induced oral mucositis is associated with detrimental bacterial dysbiosis

BACKGROUND

Gastrointestinal mucosal injury (mucositis), commonly affecting the oral cavity, is a clinically significant yet incompletely understood complication of cancer chemotherapy. Although antineoplastic cytotoxicity constitutes the primary injury trigger, the interaction of oral microbial commensals with mucosal tissues could modify the response. It is not clear, however, whether chemotherapy and its associated treatments affect oral microbial communities disrupting the homeostatic balance between resident microorganisms and the adjacent mucosa and if such alterations are associated with mucositis. To gain knowledge on the pathophysiology of oral mucositis, 49 subjects receiving 5-fluorouracil (5-FU) or doxorubicin-based chemotherapy were evaluated longitudinally during one cycle, assessing clinical outcomes, bacterial and fungal oral microbiome changes, and epithelial transcriptome responses. As a control for microbiome stability, 30 non-cancer subjects were longitudinally assessed. Through complementary in vitro assays, we also evaluated the antibacterial potential of 5-FU on oral microorganisms and the interaction of commensals with oral epithelial tissues.

RESULTS

Oral mucositis severity was associated with 5-FU, increased salivary flow, and higher oral granulocyte counts. The oral bacteriome was disrupted during chemotherapy and while antibiotic and acid inhibitor intake contributed to these changes, bacteriome disruptions were also correlated with antineoplastics and independently and strongly associated with oral mucositis severity. Mucositis-associated bacteriome shifts included depletion of common health-associated commensals from the genera Streptococcus, Actinomyces, Gemella, Granulicatella, and Veillonella and enrichment of Gram-negative bacteria such as Fusobacterium nucleatum and Prevotella oris. Shifts could not be explained by a direct antibacterial effect of 5-FU, but rather resembled the inflammation-associated dysbiotic shifts seen in other oral conditions. Epithelial transcriptional responses during chemotherapy included upregulation of genes involved in innate immunity and apoptosis. Using a multilayer epithelial construct, we show mucositis-associated dysbiotic shifts may contribute to aggravate mucosal damage since the mucositis-depleted Streptococcus salivarius was tolerated as a commensal, while the mucositis-enriched F. nucleatum displayed pro-inflammatory and pro-apoptotic capacity.

CONCLUSIONS

Altogether, our work reveals that chemotherapy-induced oral mucositis is associated with bacterial dysbiosis and demonstrates the potential for dysbiotic shifts to aggravate antineoplastic-induced epithelial injury. These findings suggest that control of oral bacterial dysbiosis could represent a novel preventive approach to ameliorate oral mucositis.

Mucosal bacterial immunotherapy with MV130 highly reduces the need of tonsillectomy in adults with recurrent tonsillitis

Recurrent tonsillitis in adults is a common ENT disease. The current standard treatment is tonsillectomy. However, continuous prophylaxis with antibiotics has been prescribed in order to avoid tonsillectomy. The objective was to evaluate if the bacterial immunotherapy (Bactek MV130) together with the prophylactic antibiotic therapy can produce clinical improvement and to avoid the tonsillectomy. Material and methods: The medical records of 88 patients with recurrent tonsillitis were reviewed. Sixty-six were treated during 3 months with a course of antibiotics and 22 received, in addition to the antibiotics, immunotherapy with Bactek MV130 during this Globally, 53 (60%) patients had clinical improvement and 35 were tonsillectomized. In the The group of patients who received only antibiotic, 35 (53%) avoided tonsillectomy and 31 (47%) did not. In the group that, in addition to antibiotics, were treated with Bactek MV130, 18 patients (82%) experi- enced clinical improvement avoiding tonsillectomy and 4 (18%) didn't improve and the tonsils were surgically removed. The difference between both groups was significant (P = 0.023).he results obtained in this evaluation support this combined treatment as an effective strategy to reduce the need of tonsillectomy.

Side effects by oral application of atmospheric pressure plasma on the mucosa in mice

Cold atmospheric pressure plasma (CAP) has been investigated with promising results for peri-implant diseases treatment. However, prior to in-vivo applications of CAP sources in humans, short-term harmful mucosal damage or other unwanted side effects have to be reviewed. 180 male mice (B6C3F1) were divided into twelve treatment groups (n = 15). The right buccal cheek mucosa was treated with CAP. The first and second group each received continuous 10 sec irradiation with 2 different plasma sources (kINPen09, PS-MWM). The third group was treated with the kINPen09 for one minute. Control groups were treated with a corresponding dose of ultraviolet light for 8 seconds or 48 seconds and the other one was left untreated. The animals were weighed before and after treatment. The animals were sacrificed one day or one week after exposure. Stained tissue samples were histologically examined for tissue damage independently by two experienced pathologists. One day after CAP treatment histological analysis showed focal mucosal erosion with superficial ulceration and necrosis accompanied by a mild inflammatory reaction. One week after CAP treatment, the mucosal defects were completely re-epithelialized, associated with remnants of granulation tissue in the stroma irrespective of treatment duration. Furthermore, no cytological atypia was found and no severe weight loss occurred. The control groups did not show any alterations at all. CAP treatment led to a superficial mucosal damage that healed within few days. Nonetheless, further long-term experiments are necessary to exclude undesirable side effects after longer observation time. Particularly, potential carcinogenic effects must be ruled out prior to the application of CAP treatment in daily dental practice.

Candida albicans induces mucosal bacterial dysbiosis that promotes invasive infection

Infectious complications are a common cause of morbidity and mortality in cancer patients undergoing chemotherapy due to increased risk of oral and gastrointestinal candidiasis, candidemia and septicemia. Interactions between C. albicans and endogenous mucosal bacteria are important in understanding the mechanisms of invasive infection. We published a mouse intravenous chemotherapy model that recapitulates oral and intestinal mucositis, and myelosuppression in patients receiving 5-fluorouracil. We used this model to study the influence of C. albicans on the mucosal bacterial microbiome and compared global community changes in the oral and intestinal mucosa of the same mice. We validated 16S rRNA gene sequencing data by qPCR, in situ hybridization and culture approaches. Mice receiving both 5Fu and C. albicans had an endogenous bacterial overgrowth on the oral but not the small intestinal mucosa. C. albicans infection was associated with loss of mucosal bacterial diversity in both sites with indigenous Stenotrophomonas, Alphaproteobacteria and Enterococcus species dominating the small intestinal, and Enterococcus species dominating the oral mucosa. Both immunosuppression and Candida infection contributed to changes in the oral microbiota. Enterococci isolated from mice with oropharyngeal candidiasis were implicated in degrading the epithelial junction protein E-cadherin and increasing the permeability of the oral epithelial barrier in vitro. Importantly, depletion of these organisms with antibiotics in vivo attenuated oral mucosal E-cadherin degradation and C. albicans invasion without affecting fungal burdens, indicating that bacterial community changes represent overt dysbiosis. Our studies demonstrate a complex interaction between C. albicans, the resident mucosal bacterial microbiota and the host environment in pathogenesis. We shed significant new light on the role of C. albicans in shaping resident bacterial communities and driving mucosal dysbiosis.

Potential Therapeutic Effects of Gut Hormones, Ghrelin and Obestatin in Oral Mucositis

Chemotherapy and/or head and neck radiotherapy are frequently associated with oral mucositis. Oral pain, odynophagia and dysphagia, opioid use, weight loss, dehydration, systemic infection, hospitalization and introduction of a feeding tube should be mentioned as the main determinated effect of oral mucositis. Oral mucositis leads to a decreased quality of life and an increase in treatment costs. Moreover, oral mucositis is a life-threatening disease. In addition to its own direct life-threatening consequences, it can also lead to a reduced survival due to the discontinuation or dose reduction of anti-neoplasm therapy. There are numerous strategies for the prevention or treatment of oral mucositis; however, their effectiveness is limited and does not correspond to expectations. This review is focused on the ghrelin and obestatin as potentially useful candidates for the prevention and treatment of chemo- or/and radiotherapy-induced oral mucositis.

Localized drug delivery with mono and bilayered mucoadhesive films and wafers for oral mucosal infections

Local drug delivery into oral cavity offers many advantages over systemic administration in treatment of the oral infections. In this study, monolayer and bilayered mucoadhesive film and wafer formulations were developed as local drug delivery platforms using chitosan and hydroxypropyl methylcellulose (HPMC). Cefuroxime axetil (CA) was used as the model drug. Surface morphology, mechanical strength, water uptake, in vitro adhesion, disintegration and in vitro release properties of the formulations were investigated. Furthermore, antimicrobial activity of the formulations was evaluated against E. coli and S. aureus. HPMC based formulations were found to disintegrate within <30 min whereas chitosan based formulations remained intact up to 6 h. Significantly higher drug release was obtained with wafer formulations. Antimicrobial activity was found to increase in presence of chitosan, and HPMC was also observed to contribute to this action. Bilayered wafer formulation, with adhesive chitosan backing layer and HPMC based drug loaded layer, providing prolonged drug release and suitable adhesive properties, with suitable mechanical strength, would be suggested as a promising local delivery system for treatment of the infections in the oral cavity.

Plant-Derived Bioactives in Oral Mucosal Lesions: A Key Emphasis to Curcumin, Lycopene, Chamomile, Aloe vera, Green Tea and Coffee Properties

Oral mucosal lesions have many etiologies, including viral or bacterial infections, local trauma or irritation, systemic disorders, and even excessive alcohol and tobacco consumption. Folk knowledge on medicinal plants and phytochemicals in the treatment of oral mucosal lesions has gained special attention among the scientific community. Thus, this review aims to provide a brief overview on the traditional knowledge of plants in the treatment of oral mucosal lesions. This review was carried out consulting reports between 2008 and 2018 of PubMed (Medline), Web of Science, Embase, Scopus, Cochrane Database, Science Direct, and Google Scholar. The chosen keywords were plant, phytochemical, oral mucosa, leukoplakia, oral lichen planus and oral health. A special emphasis was given to certain plants (e.g., chamomile, Aloe vera, green tea, and coffea) and plant-derived bioactives (e.g., curcumin, lycopene) with anti-oral mucosal lesion activity. Finally, preclinical (in vitro and in vivo) and clinical studies examining both the safety and efficacy of medicinal plants and their derived phytochemicals were also carefully addressed.

Arctigenin Reduces Myofibroblast Activities in Oral Submucous Fibrosis by LINC00974 Inhibition

Oral submucous fibrosis (OSF) is an oral precancerous condition associated with the habit of areca nut chewing and the TGF-β pathway. Currently, there is no curative treatment to completely heal OSF, and it is imperative to alleviate patients’ symptoms and prevent it from undergoing malignant transformation. Arctigenin, a lignan extracted from Arctium lappa, has been reported to have a variety of pharmacological activities, including anti-fibrosis. In the present study, we examined the effect of arctigenin on the cell proliferation of buccal mucosal fibroblasts (BMFs) and fibrotic BMFs (fBMFs), followed by assessment of myofibroblast activities. We found that arctigenin was able to abolish the arecoline-induced collagen gel contractility, migration, invasion, and wound healing capacities of BMFs and downregulate the myofibroblast characteristics of fBMFs in a dose-dependent manner. Most importantly, the production of TGF-β in fBMFs was reduced after exposure to arctigenin, along with the suppression of p-Smad2, α-smooth muscle actin, and type I collagen A1. In addition, arctigenin was shown to diminish the expression of LINC00974, which has been proven to activate TGF-β/Smad signaling for oral fibrogenesis. Taken together, we demonstrated that arctigenin may act as a suitable adjunct therapy for OSF.

Development of a Mucoadhesive and an in Situ Gelling Formulation Based on κ-Carrageenan for Application on Oral Mucosa and Esophagus Walls. II. Loading of a Bioactive Hydroalcoholic Extract

The aim of the present work was to load a Hibiscus sabdariffa (HS) hydroalcoholic extract into in situ gelling formulations for the treatment of oral mucositis and esophagitis. Such formulations, selected as the most promising options in a previous work of ours, were composed by κ-carrageenan (κ-CG), a sulfated marine polymer able to gelify in presence of saliva ions, hydroxypropyl cellulose (HPC), used as mucoadhesive agent, and CaCl₂, salt able to enhance the interaction κ-CG/saliva ions. HS extract, which is rich in phytochemicals such as polyphenols, polysaccharides and organic acids, was selected due to its antioxidant and anti-inflammatory properties. For HS extraction, three different methodologies (maceration, Ultrasound Assisted Extraction (UAE) and Microwave Assisted Extraction (MAE)) were compared in terms of extraction yield and extract antioxidant activity, revealing that MAE was the best procedure. Rheological and mucoadhesive properties of HS-loaded formulations were investigated. Such formulations were characterized by a low viscosity at 25 °C, guaranteeing an easy administration, a proper in situ gelation behavior and marked elastic and mucoadhesive properties at 37 °C, functional to a protective action towards the damaged mucosa. Finally, the biocompatibility and the proliferative effect of HS-loaded formulations, as well as their antioxidant and anti-inflammatory properties, were proved in vitro on human dermal fibroblasts.

The smokeless tobacco habit and DNA damage: A systematic review and meta-analysis

BACKGROUND

The aim of this systematic review was to evaluate the frequency of micronuclei or other DNA damage in the oral mucosa of adults that have smokeless tobacco habits compared to adults that not have these habits.

MATERIAL AND METHODS

We searched PubMed, Scopus, Web of Science, LILACS, BBO and Cochrane Library and SIGLE. We also surveyed gray literature. We included only clinical trials that compare the frequency of micronuclei or other DNA damage in the oral mucosa of adults that have smokeless tobacco habits compared to adults that not have these habits. Quality assessments of the selected trials were evaluated by two independent reviewers, using the Effective Public Health Practice Project - (EPHPP) with modifications.

RESULTS

After the database screening and removal of duplicates, 2574 studies were identified. After title screening, 172 studies remained, and this number was reduced to 25 after careful examination of the abstracts. The standardized mean difference of the frequency of micronuclei between groups was 1.88, with a 95% confidence interval of 1.40 to 2.36 (p < 0.00001). In all analyses heterogeneity was detected.

CONCLUSIONS

Despite the heterogeneity of studies, the frequency of micronuclei was significant bigger in adults who have the smokeless tobacco habit when compared to those not have this habit. The same occurred with the frequency of binucleated cells, karyolisis and karyorrhexis.

Development of a Mucoadhesive and In Situ Gelling Formulation Based on κ-Carrageenan for Application on Oral Mucosa and Esophagus Walls. I. A Functional In Vitro Characterization

Oral mucositis and esophagitis represent the most frequent and clinically significant complications of cytoreductive chemotherapy and radiotherapy, which severely compromise the patient quality of life. The local application of polymeric gels could protect the injured tissues, alleviating the most painful symptoms. The present work aims at developing in situ gelling formulations for the treatment of oral mucositis and esophagitis. To reach these targets, κ-carrageenan (κ-CG) was selected as a polymer having wound healing properties and able to gelify in the presence of saliva ions, while hydroxypropyl cellulose (HPC) was used to improve the mucoadhesive properties of the formulations. CaCl₂ was identified as a salt able to enhance the interaction between κ-CG and saliva ions. Different salt and polymer concentrations were investigated in order to obtain a formulation having the following features: (i) low viscosity at room temperature to facilitate administration, (ii) marked elastic properties at 37 °C, functional to a protective action towards damaged tissues, and (iii) mucoadhesive properties. Prototypes characterized by different κ-CG, HPC, and CaCl₂ concentrations were subjected to a thorough rheological characterization and to in vitro mucoadhesion and washability tests. The overall results pointed out the ability of the developed formulations to produce a gel able to interact with saliva ions and to adhere to the biological substrates.

Induction of chromosomal damage in exfoliated buccal and nasal cells of road markers

Road markers are exposed to various chemicals and particles. The aim of this study was to determine whether road worker exposure induceschromosomal damage which is indicative for increased cancer risks. Micronucleus (MN) cytome assays were thus conducted with exfoliated nasal and buccal cells collected from 42 workers and 42 matched controls. The frequencies of MN (reflecting chromosomal aberrations), nuclear buds (NBuds; reflecting gene amplifications) and binucleated cells (BN; reflecting disturbed mitosis) were scored. Further, the rates of nuclear anomalies indicative of acute cytotoxicity (condensed chromatin, karyorrhexis, karyolysis, pyknosis) were evaluated. Data demonstrated marked induction of MN, NBuds, and BN by 1.34-fold, 1.24-fold and 1.14-fold in buccal cells. In nasal cells, only MN frequencies were elevated, 1.23-fold. These effects were paralleled by increased rates of condensed chromatin, karyorrhexis and karyolysis in both cell types. The effects were more pronounced in individuals who had worked for more than 10 years while smoking did not produce synergistic responses. This is the first investigation concerning the induction of genetic damage in road markers and the results are suggestive for enhanced cancer risks. It is conceivable that exposure to silica dust (known to induce cancer and genetic damage) and/or benzoyl peroxide which forms reactive radicals may be associated with the observed genetic damage in road workers. Further investigations of the cancer risks of these workers are warranted.