Comparative study of the effects of cigarette smoke and electronic cigarettes on human gingival fibroblast proliferation, migration and apoptosis

Oral Mucosa and Saliva Alterations Related to Vape

OBJECTIVES

Electronic nicotine delivery systems (e-cigarette, pod, and vape) are currently among the tobacco consumption of adolescents and young adults. The aim is to show oral mucosa and saliva alterations related to vape.

MATERIAL AND METHODS

A vape-user patient, presenting a white plaque in the posterior region of the hard palate, underwent clinical examination, sialometry, pH evaluation, and excisional biopsy of the white lesion. Molecular changes in saliva and vape liquid were analyzed by vibrational spectroscopy.

RESULTS

The histopathological analyses showed hyperparakeratosis without dysplasia. Formaldehyde, ketones, and aromatic hydrocarbon species were identified in e-cig liquid by the FTIR.

CONCLUSIONS

The use of vape may be related to the development of hyperkeratotic lesions in the oral mucosa as well as significantly modify the patient's salivary patterns as the vape liquid presents carcinogenic and cytotoxic components in its composition.

Perinatal nicotine vaping exposure induces pro-myofibroblastic phenotype in rat bone marrow-derived mesenchymal stem cells

Perinatal nicotine exposure via tobacco smoking results in increased proclivity to chronic lung disease (CLD); however, the underlying molecular mechanisms remain incompletely understood. We previously demonstrated that in addition to nicotine's direct effects on the developing lung, there are also adverse molecular alterations in bone marrow-derived mesenchymal stem cells (BMSCs), which are vital to lung injury repair. Whether perinatal nicotine exposure via electronic-cigarette (e-cig) vaping also adversely affects BMSCs is unknown. This is highly relevant due to marked increase in e-cig vaping including by pregnant women. Hypothesizing that perinatal nicotine exposure via e-cig vaping predisposes BMSCs to a pro-myofibroblastic phenotype, pregnant rat dams were exposed to fresh air (control), vehicle (e-cig without nicotine), or e-cig (e-cig with nicotine) daily during pregnancy and lactation. At postnatal day 21, offspring BMSCs were isolated and studied for cell proliferation, migration, wound healing response, and expression of key Wnt and PPARγ signaling intermediates (β-catenin, LEF-1, PPARγ, ADRP and C/EBPα) and myogenic markers (fibronectin, αSMA, calponin) proteins using immunoblotting. Compared to controls, perinatal e-cig exposure resulted in significant decrease in BMSC proliferation, migration, and wound healing response. The expression of key Wnt signaling intermediates (β-catenin, LEF-1) and myogenic markers (fibronectin, αSMA, calponin) increased significantly, while PPARγ signaling intermediates (PPARγ, ADRP, and C/EBPα) decreased significantly. Based on these data, we conclude that perinatally e-cig exposed BMSCs demonstrate pro-myofibroblastic phenotype and impaired injury-repair potential, indicating a potentially similar susceptibility to CLD following perinatal nicotine exposure via vaping as seen following parenteral perinatal nicotine exposure.

A pilot study on oral microbiome in electronic cigarettes consumers versus traditional cigarettes smokers

Oral microorganisms are closely related to oral health, the occurrence of some oral diseases is associated with changes in the oral microbiota, and many studies have demonstrated that traditional smoking can affect the oral microbial community. However, due to the short time since the emergence of e-cigarettes, fewer studies are comparing oral microorganisms for users of e-cigarettes versus cigarettes. We collected saliva from 40 non-smokers (NS), 46 traditional cigarette smokers (TS), and 27 e-cigarette consumers (EC), aged between 18 and 35 years. We performed 16S rRNA gene sequencing on the saliva samples collected to study the effects of e-cigarettes versus traditional cigarettes on the oral microbiome. The results showed that compared with the NS group, the alpha diversity of oral flora in saliva was altered in the TS group, with no significant change in the e-cigarette group. Compared with the NS and EC groups, the relative abundance of Actinomyces and Prevotella was increased in the TS group. However, compared with the NS and TS groups, the relative abundance of Veillonella was increased, and the relative abundance of Porphyromonas and Peptostreptococcus was decreased in the EC group. These results showed that both e-cigarettes and traditional cigarettes could alter the structure and composition of oral microbiota. The use of traditional cigarettes promotes the growth of some anaerobic bacteria, which may contribute to dental decay and bad breath over time. E-cigarettes have a different effect on the structure and composition of the oral microbial community compared to conventional cigarettes. In order to better understand the effects of e-cigarettes and traditional cigarettes on users' mouths, future studies will investigate the relationship between diseases such as dental caries and periodontitis and changes in oral microbial species levels.

Dual Exposure to E-Cigarette Vapour and Cigarette Smoke Results in Poorer Airway Cell, Monocyte, and Macrophage Function Than Single Exposure

E-cigarette users predominantly also continue to smoke cigarettes. These Dual Users either consume e-cigarettes in locations where smoking is not allowed, but vaping is, or to reduce their consumption of cigarettes, believing it will lead to harm reduction. Whilst it is known that e-cigarette vapour is chemically less complex than cigarette smoke, it has a distinct chemical profile, and very little is known about the health impacts of exposure to both chemical profiles vs. either alone. We simultaneously exposed cells in vitro to non-toxic levels of e-cigarette vapour extract (EVE) and cigarette smoke extract (CSE) to determine their effects on 16HBE14o- airway epithelial cell metabolism and inflammatory response, as well as immune cell (THP-1 cells and monocyte-derived macrophages (MDM) from healthy volunteers) migration, phagocytosis, and inflammatory response. We observed increased toxicity, reduced metabolism (a marker of proliferation) in airway epithelial cells, and reduced monocyte migration, macrophage phagocytosis, and altered chemokine production after exposure to either CSE or EVE. These cellular responses were greater after dual exposure to CSE and EVE. The airway epithelial cells from smokers showed reduced metabolism after EVE (the Switcher model) and dual CSE and EVE exposure. When EVE and CSE were allowed to interact, the chemicals were found to be altered, and new chemicals were also found compared to the CSE and EVE profiles. Dual exposure to e-cigarette vapour and cigarette smoke led to worse functional outcomes in cells compared to either single exposure alone, adding to limited data that dual use may be more dangerous than smoking only.

Comparative analyses of transcriptome sequencing and carcinogenic exposure toxicity of nicotine and 6-methyl nicotine in human bronchial epithelial cells

Electronic cigarettes have become a purported safer alternative to the conventional cigarettes in recent years. Nicotine is the main component of electronic cigarettes, and other nicotinic compounds are synthesized as alternatives to nicotine. However, scientific data on the potential health effects of electronic cigarettes are scarce. Herein, we evaluated the cytotoxicity of nicotine and its analog 6-methyl nicotine (6-MN) on human bronchial epithelial cells (BEAS-2B cells) in vitro. Furthermore, we performed transcriptome sequencing to systematically assess the effects of nicotine and 6-MN on BEAS-2B cells. The cytotoxicity assay revealed that BEAS-2B cells were more sensitive to 6-MN than to nicotine. Transcriptome sequencing revealed 1208 differentially expressed cancer-related proteins (CRP) in the 6-MN groups relative to that with CRP in the control group. In addition, 6-MN had a greater negative effect on the CRP expression than nicotine. Bioinformatic analysis revealed that the differentially expressed genes and proteins in the 6-MN group were significantly enriched in the cancer-related pathways, unlike those in the nicotine group. Further validations of some lung cancer-related proteins, such as NF-κB p65, EGFR, and MET, were conducted by immunoblotting and real-time PCR, which revealed that 6-MN may have a greater negative effect on tumor development and metastasis than nicotine. Taken together, our findings suggest that new electronic cigarettes with 6-MN might offer some advantages over conventional electronic cigarettes containing nicotine.

Electronic cigarette exposure disrupts airway epithelial barrier function and exacerbates viral infection

The use of electronic cigarettes (e-cigs), especially among teenagers, has reached alarming and epidemic levels, posing a significant threat to public health. However, the short- and long-term effects of vaping on the airway epithelial barrier are unclear. Airway epithelial cells are the forefront protectors from viruses and pathogens. They contain apical junctional complexes (AJCs), which include tight junctions (TJs) and adherens junctions (AJs) formed between adjacent cells. Previously, we reported respiratory syncytial virus (RSV) infection, the leading cause of acute lower respiratory infection-related hospitalization in children and high-risk adults, induces a "leaky airway" by disrupting the epithelial AJC structure and function. We hypothesized chemical components of e-cigs disrupt airway epithelial barrier and exacerbate RSV-induced airway barrier dysfunction. Using confluent human bronchial epithelial (16HBE) cells and well-differentiated normal human bronchial epithelial (NHBE) cells, we found that exposure to extract and aerosol e-cig nicotine caused a significant decrease in transepithelial electrical resistance (TEER) and the structure of the AJC even at noncytotoxic concentrations. Western blot analysis of 16HBE cells exposed to e-cig nicotine extract did not reveal significant changes in AJC proteins. Exposure to aerosolized e-cig cinnamon or menthol flavors also induced barrier disruption and aggravated nicotine-induced airway barrier dysfunction. Moreover, preexposure to nicotine aerosol increased RSV infection and the severity of RSV-induced airway barrier disruption. Our findings demonstrate that e-cig exposure disrupts the airway epithelial barrier and exacerbates RSV-induced damage. Knowledge gained from this study will provide awareness of adverse e-cig respiratory effects and positively impact the mitigation of e-cig epidemic.NEW & NOTEWORTHY Electronic cigarette (e-cig) use, especially in teens, is alarming and at epidemic proportions, threatening public health. Our study shows that e-cig nicotine exposure disrupts airway epithelial tight junctions and increases RSV-induced barrier dysfunction. Furthermore, exposure to aerosolized flavors exaggerates e-cig nicotine-induced airway barrier dysfunction. Our study confirms that individual and combined components of e-cigs deleteriously impact the airway barrier and that e-cig exposure increases susceptibility to viral infection.

Chemical analysis of selected harmful and potentially harmful constituents and in vitro toxicological evaluation of leading flavoured e-cigarette aerosols in the Chinese market

Use of electronic cigarettes (e-cigarettes) has increased significantly over the past decade due to consumer perception that these products represent a less risky alternative to combustible cigarettes. E-liquids generally contain a simple mix of vegetable glycerin, propylene glycerol, nicotine, organic acids, and flavourings. Regulators require that harmful and potentially harmful constituents (HPHCs) that might cause harm to the consumer must be monitored in the aerosol generated by e-cigarettes and in cigarette smoke (CS). To quantify HPHCs in aerosols from commercial flavoured e-cigarettes in Chinese market, this study has systematically compared levels of HPHCs, including eight carbonyls, five volatile organic compounds, four tobacco-specific nitrosamines, 16 polycyclic aromatic hydrocarbons, and seven heavy metals, in the aerosols of four market-leading flavoured e-cigarettes and mainstream CS, alongside in vitro cytotoxicity and mutagenicity assays. The vast majority of HPHCs were either undetected or significantly lower in the e-cigarette aerosols than in commercial CS or reference CS (3R4F). Where HPHCs were detected, there were small variations among the different flavoured e-cigarettes. In the neutral red uptake and Ames assays, aqueous extracts of the e-cigarette aerosols did not induce obvious cytotoxicity or mutagenicity, whereas CS aqueous extract showed dose-related cytotoxicity and mutagenicity. Collectively, these results indicate that use of e-cigarettes might potentially lead to a significant reduction in exposure to harmful substances, with fewer cytotoxic and mutagenic effects, as compared with conventional smoking. Further studies based on human puffing conditions and longer evaluation periods will be needed to substantiate this potential.

The Apoptotic Activity of Curcumin Against Oral Cancer Cells Without Affecting Normal Cells in Comparison to Paclitaxel Activity

Until now, chemotherapy, which has a series of side effects, has been the most widely employed treatment for different types of cancer. However, bioactive products have been utilized as alternative medicines for tumors due to their bioactivities with low or no side effects in normal cells. This research reported for the first time that curcumin (CUR) and paclitaxel (PTX) have significant anti-cancer activity against normal human gingival fibroblast (HGF) and tongue squamous cell carcinoma fibroblast (TSCCF) cell lines. The results showed that CUR (13.85 µg mL-1) and PTX (8.17 µg mL-1) significantly inhibited TSCCF cell viability, with no significant effect on normal HGF cells. SEM showed morphological changes in cells treated with CUR and PTX, especially with TSCCF cells, compared to HGF normal cells. For TSCCF, the results showed the highest necrosis was achieved with CUR (58.8%) and PTX (39%) as compared to the control (2.99%). For normal HGF cells, the highest early and late apoptosis was achieved with PTX. Further, DCFH-DA analyses showed no significant ROS stimulation in TSCCF and HGF cell lines treated with CUR and PTX. The 1H NMR analysis results show the presence of methoxy and hydroxyl groups and aromatic hydrogens in the CUR structure. In conclusion, the results confirmed that CUR is more specific to the oral cancer cells but not normal cells by inducing apoptosis in a dose- and time-dependent manner, with decreased TSCCF cell viability, and the cytotoxicity of CUR and PTX is not through the ROS pathway.

Evaluation of the effects of e-cigarette aerosol extracts and tobacco cigarette smoke extracts on human gingival epithelial cells

Smoking increases the risk of a number of diseases, including cardiovascular, oral and lung diseases. E-cigarettes are gaining popularity among young people as an alternative to cigarettes, but there is debate over whether they are less harmful to the mouth than e-cigarettes. In this study, human gingival epithelial cells (HGECs) were treated with four commercially available e-cigarette aerosol condensates (ECAC) or commercially available generic cigarette smoke condensates (CSC) with different nicotine concentrations. Cell viability was determined by MTT assay. Cell apoptosis was observed by acridine orange (AO) and Hoechst33258 staining. The levels of type I collagen, matrix metalloproteinase (MMP-1, MMP-3), cyclooxygenase 2 and inflammatory factors were detected by ELISA and RT-PCR. Finally, ROS levels were analyzed by ROS staining. The different effects of CSC and ECAC on HGECs were compared. The results showed that higher nicotine concentration of CS significantly reduced the activity of HGECs. By contrast, all ECAC had no significant effect. The levels of matrix metalloproteinase, COX-2, and inflammatory factors were higher in HGECs treated with CSC than those treated with ECAC. In contrast, the level of type I collagen was higher in HGECs treated with ECAC than those treated with CSC. In conclusion, all four flavors of e-cigarettes were less toxic to HGE cells than tobacco, but further clinical studies are needed to determine whether e-cigarettes are less harmful to oral health than conventional cigarettes.

Transcriptome characterization of human gingival mesenchymal and periodontal ligament stem cells in response to electronic-cigarettes

The potential toxicities and threats of electronic cigarettes (E-cigs) on periodontal health remain elusive. Gingival mesenchymal stem cells (GMSCs) and periodontal ligament stem cells (PDLSCs) contribute to cell differentiation and regeneration for periodontium as well as inflammatory modulation. However, the effects of E-cig exposure on periodontal tissues, particularly GMSCs and PDLSCs, and the underlying epigenetic mechanisms remain largely unknown. In this study, we conducted RNA-seq analysis to examine the transcriptome of human GMSCs and PDLSCs exposed to four types of E-cigs (aerosol and liquid with tobacco and menthol flavor) and conventional tobacco smoke in vitro. Our results showed that E-cig exposure primarily impacted the immunoregulation and inflammatory responses to pathogenic microorganisms in GMSCs, and the microenvironment, differentiation and response to corticosteroid in PDLSCs, which were significantly different from the damage effects caused by tobacco smoke. Additionally, we discovered a large number of differentially expressed non-coding RNAs among the different E-cig exposure methods and flavors. We also noticed that in GMSCs, CXCL2 was especially down-regulated by E-cig aerosol exposure whereas up-regulated by E-liquid exposure compared to control. Of note, the enhancer elements near CXCL2 and other genes located at Chromosome 4 contributed to the transcription activity of these genes, and KDM6B was remarkably elevated in response to E-liquid exposure. Lastly, we conducted ChIP-seq analysis to confirm that the elevated gene transcription by E-liquids was due to the weakened H3K27me3 at genome-wide enhancer elements in GMSCs, but not at promoter regions. Taken together, our results characterized the diverse gene expression profiles of GMSCs and PDLSCs in response to E-cigs with different exposure methods and flavors in vitro, and indicated a novel mechanism of KDM6B-mediated H3K27me3 on enhancers for gene transcription regulation. Our data could be served as a resource for emphasizing the understanding of E-cigs in periodontal health.

Effect of cannabis smoke condensate on human nasal epithelial cell adhesion, growth, and migration

OBJECTIVE

When inhaled, cannabis smoke interacts with airway tissues, including the nasal mucosa, which may lead to nasal pathologies. We examined the effect of cannabis smoke condensate (CSC) on nasal epithelial cell and tissue behaviors.

METHODS

Human nasal epithelial cells were exposed or not to CSC at different concentrations (1, 5, 10, and 20 %) and for different durations. Cell adhesion and viability were assessed, as well as post-wound cell migration and lactate dehydrogenase (LDH) release.

RESULTS

The nasal epithelial cells showed a larger cell size and a faint nucleus following exposure to CSC, compared to that observed in that control. This was supported by fewer adherent cells present after exposure for either 1 or 24 h to 5, 15, and 20 % CSC. CSC also had a significant toxic effect by reducing cell viability after both 1 and 24 h of exposure. This toxic effect was significant even at a low concentration (1 %) of CSC. The effects on nasal epithelial cell viability were confirmed by the decrease in cell migration. After the scratch and subsequent exposure to CSC for either 6 or 24 h, a complete inhibition of nasal epithelial cell migration was observed, compared to that found in the controls. CSC was toxic to the nasal epithelial cells, as the level of LDH significantly increased following cell exposure all CSC concentrations.

CONCLUSION

Cannabis smoke condensate had a negative effect on several nasal epithelial cell behaviors. These findings indicate that cannabis smoke could be a threat to nasal tissues and ultimately lead to nasal and sinus disorders.

Evaluation of the Effects of E-Cigarette Aerosol Extracts and Tobacco Cigarette Smoke Extracts on Human Gingival Epithelial Cells

Smoking increases the risk of a number of diseases, including cardiovascular, oral, and lung diseases. E-cigarettes are gaining popularity among young people as an alternative to cigarettes, but there is debate over whether they are less harmful to the mouth than e-cigarettes. In this study, human gingival epithelial cells (HGECs) were treated with four commercially available e-cigarette aerosol condensates (ECAC) or commercially available generic cigarette smoke condensates (CSC) with different nicotine concentrations. Cell viability was determined by MTT assay. Cell apoptosis was observed by acridine orange (AO) and Hoechst33258 staining. The levels of type I collagen, matrix metalloproteinase (MMP-1, MMP-3), cyclooxygenase 2, and inflammatory factors were detected by ELISA and RT-PCR. Finally, ROS levels were analyzed by ROS staining. The different effects of CSC and ECAC on HGECs were compared. The results showed that higher nicotine concentration of CS significantly reduced the activity of HGECs. By contrast, all ECAC had no significant effect. The levels of matrix metalloproteinase, COX-2, and inflammatory factors were higher in HGECs treated with CSC than those treated with ECAC. In contrast, the level of type I collagen was higher in HGECs treated with ECAC than those treated with CSC. In conclusion, all four flavors of e-cigarettes were less toxic to HGE cells than tobacco, but further clinical studies are needed to determine whether e-cigarettes are less harmful to oral health than conventional cigarettes.

The implications of vaping on surgical wound healing: A systematic review

BACKGROUND

E-cigarette use is rapidly growing, and little is known about the postoperative complications. Cigarette smoking has been well-established to be associated with delayed wound healing and increased complications in surgical patients. Due to the intricate and harmonious nature of the wound-healing process, vaping may impair tissue regeneration, posing a risk for patients undergoing surgery. This systematic review aimed to review the evidence on the implications of vaping on wound healing.

METHODS

A systematic search of PubMed and Scopus databases was conducted on October 2022 per Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. The following keywords were used to conduct the search: vaping, vape, e-cigarettes, electronic cigarettes, wound healing, tissue regeneration, postoperative complications, wound infection, and blood flow.

RESULTS

Of 5,265 screened articles, only 37 were eligible for qualitative synthesis. A total of 18 articles studied the effect of e-cigarettes on human volunteers, 14 investigated e-cigarette extract on human cell lines, and 5 used animal rat models.

CONCLUSION

Despite limited objective data, the recommendation is that e-cigarettes be treated as tobacco cigarettes; hence, vaping should be stopped in the perioperative period to decrease the incidence of wound healing complications. Clinical trials are required to understand the health hazards of e-cigarettes further and maximize patient safety and clinical outcomes.

Impact of Electronic Cigarettes on the Upper Aerodigestive Tract: A Comprehensive Review for Otolaryngology Providers

Objective

The use and effects of electronic (e)-cigarettes (e-cigs) are particularly relevant for otolaryngology providers as tobacco plays a major role in benign and malignant diseases of the upper aerodigestive tract. This review aims to (1) summarize the recent policies regarding e-cigs and important patterns of use and (2) serve as a comprehensive resource for clinical providers on the known biologic and clinical effects of e-cigs on the upper aerodigestive tract.

Data Sources

PubMed/MEDLINE.

Review Methods

We conducted a narrative review on (1) general information on e-cig use and informative findings in the lower respiratory system and a comprehensive review on (2) the effects of e-cigs on cell and animal models and the clinical implications of these products on human health as is relevant to otolaryngology.

Conclusions

Although e-cigs are likely less harmful than conventional cigarettes, preliminary research on e-cigs suggest several deleterious effects including in the upper aerodigestive tract. Due to this, there has been increased interest in restricting e-cig usage, particularly among the adolescent population, and caution in recommending e-cigs to current smokers.

Implications for Practice

Chronic e-cig use is likely to have clinical implications. It is critical for otolaryngology providers to be aware of the rapidly changing regulations and use patterns regarding e-cigs and how e-cigs influence human health, particularly with regards to the upper aerodigestive tract, to accurately council patients regarding potential risks and benefits of use.

In Vitro Toxicological Investigation and Risk Assessment of E-Cigarette Aerosols Based on a Novel Solvent-Free Extraction Method

Cigarettes, potentially safer alternatives to combustible cigarettes, have been reported to increase the health risk for long-term users, so accumulating information about their potential toxicity is of great concern. However, toxicological evaluations of e-cigarette aerosols are limited, which may be attributed to the lack of a simple and efficient extraction method. Here, we developed a high-speed centrifugal method for extracting e-cigarette aerosol collected mass (ACM) and prepared ACM samples of 26 representative e-cigarettes, and 10 samples were further selected based on their cytotoxicity for systematic toxicological assessments. The average extraction efficiency of ACM, primary aerosol components, and typical carbonyls exceeded 85%. The toxicological evaluation showed that the IC₅₀ value range of e-cigarettes for cytotoxicity was 2-52 mg/mL ACM, all e-cigarettes can induce the risk of DNA damage, mitochondrial depolarization, and c-Jun-related signal disturbances; most e-cigarettes significantly caused disturbance of oxidative stress balance. E-cigarettes with higher cytotoxicity appeared to cause a higher degree of damage, while no e-cigarette promoted mutagenicity and cytochrome c release. The toxicity difference among e-cigarettes using nicotine equivalent was significantly lower than that of ACM. This study provides a novel extraction method and a comprehensive in vitro toxicity risk profile of e-cigarette aerosols.

Comparison of Whole Salivary Cortisol and Interleukin 1-Beta Levels in Light Cigarette-Smokers and Users of Electronic Nicotine Delivery Systems before and after Non-Surgical Periodontal Therapy

There are no studies that have compared whole salivary cortisol (CL) and interleukin 1-beta (IL-1β) levels in cigarette-smokers (CS) and electronic nicotine delivery systems (ENDS)-users before and after non-surgical periodontal therapy (NSPT). The aim was to compare whole salivary CL and IL-1β levels in light CS and ENDS users before and after non-surgical periodontal therapy (NSPT). Self-reported current CS, ENDS users, and non-smokers were included. A questionnaire was used to collect demographic data. All patients underwent NSPT. Periodontal parameters (probing depth (PD], gingival index (GI], clinical attachment loss (AL], plaque index (PI], and marginal bone loss (MBL]) and whole salivary CL and IL-1β were measured at baseline. At 3-months of follow-up, clinical parameters and whole salivary CL and IL-1β were re-assessed. p-values < 1% were arbitrated as statistically significant. Fifty-four individuals (18 CS, 18 ENDS users, and 18 non-smokers) were included. Clinical AL, MT, PD, PI, and MBL were similar in all groups at baseline. At 12-weeks of follow-up, PI (p < 0.01) and PD (p < 0.01) were high in CS and ENDS-users than non-smokers. Among non-smokers, there was a statistically significant correlation between whole salivary cortisol and IL-1β levels at 12-weeks' follow-up (p < 0.001). There was no difference in whole salivary cortisol and IL-1β levels in CS and ENDS users at baseline and at 12-weeks follow-up. At 12-weeks of follow-up, there was a significant reduction in IL-1β (p < 0.01) and CL (p < 0.01) than baseline. In light CS and ENDS users without periodontal disease, clinical periodontal parameters and whole-salivary CL and Il-1β levels remain unchanged after NSPT.

Cannabis smoke condensate induces human gingival epithelial cell damage through apoptosis, autophagy, and oxidative stress

OBJECTIVES

This study aims to investigate the effects of cannabis smoke condensate (CSC) on the adhesion, growth, and signaling pathways of human gingival epithelial cells.

DESIGN

The effects of CSC on cell shape and adhesion, and viability were evaluated after 30 min, 60 min, 2 h, and 24 h of exposure using microscopic observation, cell metabolic activity, and lactate dehydrogenase activity assays. The effects of CSC on cell apoptosis, necrosis, autophagy, and oxidative stress were determined through flow cytometry, while apoptotic and autophagic gene expression were identified via an RT2-PCR array. Phosphorylated signaling pathway proteins were measured using flow cytometry.

RESULTS

CSC deregulated gingival epithelial cell shape and adhesion, decreased cell viability, and increased lactate dehydrogenase release. Its toxic effects included apoptosis, autophagy, and oxidative stress. Moreover, it modulated seven specific apoptotic and six autophagic genes. Furthermore, it decreased phosphorylation in signaling proteins, such as STAT5, ERK12, P38, and nuclear factor κB.

CONCLUSIONS

CSC has notable adverse effects on gingival epithelial cells. This finding indicates that cannabis smoke could impair gingival epithelial cell innate immune function, leading to gingivitis and periodontitis. Oral health professionals may need to document observed modifications in the oral cavity of patients who smoke cannabis and consider these potential changes during clinical care.

Effect of Cigarette Smoking on Midterm Outcomes After Arthroscopic Surgery for Femoroacetabular Impingement Syndrome: A Propensity-Matched Controlled Study With Minimum 5-Year Follow-up

Background:

There is limited literature evaluating patient-reported outcomes (PROs) in cigarette smokers undergoing hip arthroscopy for femoroacetabular impingement syndrome (FAIS) at midterm follow-up.

Purpose:

(1) To report minimum 5-year PROs for cigarette-smoking patients who underwent primary hip arthroscopy for FAIS and (2) to compare these results with a propensity-matched control group of never-smoking patients.

Study Design:

Cohort study; Level of evidence, 3.

Methods:

Data were collected for all patients who underwent primary hip arthroscopy for FAIS between June 2009 and March 2016. Patients were eligible if they indicated that they smoked cigarettes within 1 month of surgery and had minimum 5-year postoperative outcomes for the modified Harris Hip Score, Nonarthritic Hip Score, Hip Outcome Score–Sport Specific Subscale (HOS-SSS), and International Hip Outcome Tool–12 (iHOT-12). The percentages of patients achieving the Patient Acceptable Symptom State (PASS) and maximum outcome improvement satisfaction threshold were recorded. The study group was then propensity matched in a 1:2 ratio to patients who had never smoked for comparison.

Results:

Included were 35 patients (35 hips) with a mean age of 39.4 ± 13.0 years and mean follow-up of 64.6 ± 4.1 months. These patients demonstrated significant improvement from preoperatively to a minimum 5-year follow-up for all recorded PROs (P < .05). When compared with 70 control patients (70 hips), smoking patients demonstrated significantly worse preoperative scores for all PROs (P < .05). Study patients also demonstrated worse minimum 5-year scores for all recorded PROs compared with control patients, which did not reach statistical significance but trended toward significance for HOS-SSS (70.4 vs 81.9; P = .076) and iHOT-12 (74.7 vs 82.2; P = .122). Smoking patients also trended toward lower rates of achieving PASS for the iHOT-12 compared with never-smoking patients (50.0% vs 68.2%; P = .120).

Conclusion:

Patients who smoked cigarettes and underwent primary hip arthroscopy for FAIS demonstrated significant improvement in PROs at a minimum 5-year follow-up. When compared with a propensity-matched control group of never-smokers, they trended toward lower postoperative HOS-SSS and iHOT-12 scores and lower rates of achieving PASS on the iHOT-12.

A Review of Toxicity Mechanism Studies of Electronic Cigarettes on Respiratory System

Electronic cigarettes (e-cigarettes) have attracted much attention as a new substitute for conventional cigarettes. E-cigarettes are first exposed to the respiratory system after inhalation, and studies on the toxicity mechanisms of e-cigarettes have been reported. Current research shows that e-cigarette exposure may have potentially harmful effects on cells, animals, and humans, while the safety evaluation of the long-term effects of e-cigarette use is still unknown. Similar but not identical to conventional cigarettes, the toxicity mechanisms of e-cigarettes are mainly manifested in oxidative stress, inflammatory responses, and DNA damage. This review will summarize the toxicity mechanisms and signal pathways of conventional cigarettes and e-cigarettes concerning the respiratory system, which could give researchers a better understanding and direction on the effects of e-cigarettes on our health.

Implications of Electronic Cigarettes on the Safe Administration of Sedation and General Anesthesia in the Outpatient Dental Setting

Today the number of electronic cigarette users continues to rise as electronic cigarettes slowly, yet steadily overtake conventional cigarettes in popularity. This shift is often attributed to the misconception that electronic cigarettes are "safer" or "less dangerous" than conventional cigarettes. Recent studies have shown that electronic cigarettes are far from safe and that the inhaled agents and byproducts within vaping aerosols can have adverse effects on systemic and oral health like combustible tobacco products. The first electronic cigarettes were originally introduced as a tool for smoking cessation. However, newer iterations of electronic cigarette devices have been modified to allow the user to consume tetrahydrocannabinol (THC), the psychoactive component of cannabis, in addition to nicotine. As the popularity of these devices continues to rise, the number of patients seeking dental treatment who also consume electronic cigarettes will too. This article aims to shed light on the deleterious effects electronic cigarettes can have on systemic and oral health, as well as the special considerations for sedation and anesthesia providers treating patients who use electronic cigarettes.

Effect of Cannabis Smoke Condensate on C. albicans Growth and Biofilm Formation

The most common use of cannabis is smoking. The oral ecosystem, among other constituents, can be deregulated by the presence of cannabis smoke in the oral cavity. We evaluated the effect of cannabis smoke condensate (CSC) on the behavior of Candida albicans, a common yeast found in the oral cavity. The yeast was first cultured with different concentrations of CSC, and its growth was evaluated. The transition from the blastospore to the hyphal form and the hyphae size were assessed after 3 and 6 h, along with biofilm formation after 72 h of contact with CSC. The response of C. albicans to oxidative (H₂O₂) stress was also examined. Our results show that CSC contained high amounts of THC (about 1055 ppm), CBN (63 ppm), and CBG (about 47 ppm). The presence of various concentrations of CSC in the culture medium increased C. albicans growth. CSC also contributed to increases in both the hyphal length and biofilm mass. Following oxidative stress (H₂O₂ at either 100 or 500 μM), CSC prevented the damaging effect of H₂O₂ on both C. albicans shape and growth. These findings support clinical observations demonstrating that cannabis may promote C. albicans growth and oral candidiasis.

In vitro evaluation of the effect of the electronic cigarette aerosol, Cannabis smoke, and conventional cigarette smoke on the properties of gingival fibroblasts/gingival mesenchymal stem cells

OBJECTIVE

The current study aimed to evaluate the effect of electronic cigarette (EC) aerosol, Cannabis, and conventional cigarettes smoke on gingival fibroblast/gingival mesenchymal stem cells' (GF/G-MSCs) of never smokers.

MATERIAL AND METHODS

Human GF/G-MSCs (n = 32) were isolated and characterized using light microscopy, flow cytometry, and multilineage differentiation ability. Following the application of aerosol/smoke extracts, GF/G-MSCs were evaluated for cellular proliferation; colony-forming units (CFU-F) ability; cellular viability (using the MTT assay); mitochondrial depolarization using JC-1 dye; and genes' expression of ATM, p21, Oct4, and Nanog.

RESULTS

Colony-forming units and viability (OD 450 nm) were significantly reduced upon exposure to Cannabis (mean ± SD; 5.5 ± 1.5; p < .00001, 0.47 ± 0.21; p < .05) and cigarettes smoke (2.3 ± 1.2 p < .00001, 0.59 ± 0.13, p < .05), while EC aerosol showed no significant reduction (10.8 ± 2.5; p = .05, 1.27 ± 0.47; p > .05) compared to the control group (14.3 ± 3, 1.33 ± 0.12). Significantly upregulated expression of ATM, Oct4, and Nanog (gene copies/GADPH) was noticed with Cannabis (1.5 ± 0.42, 0.82 ± 0.44, and 1.54 ± 0.52, respectively) and cigarettes smoke (1.52 ± 0.75, 0.7 ± 0.14, and 1.48 ± 0.79, respectively; p < .05), whereas EC aerosol caused no statistically significant upregulation of these genes compared to the control group (0.63 ± 0.1, 0.31 ± 0.12, and 0.64 ± 0.46, respectively; p > .05). The p21 gene was not significantly downregulated in EC aerosol (1.22 ± 0.46), Cannabis (0.71 ± 0.24), and cigarettes smokes (0.83 ± 0.54) compared to the control group (p = .053, analysis of variance).

CONCLUSION

Cannabis and cigarettes smoke induce DNA damage and cellular dedifferentiation and negatively affect the cellular proliferation and viability of GF/G-MSCs of never smokers, whereas EC aerosol showed a significantly lower impact on these properties.

Cortactin Modulates Lung Endothelial Apoptosis Induced by Cigarette Smoke

Cigarette smoke (CS) is the primary cause of Chronic Obstructive Pulmonary Disease (COPD), and an important pathophysiologic event in COPD is CS-induced apoptosis in lung endothelial cells (EC). Cortactin (CTTN) is a cytoskeletal actin-binding regulatory protein with modulation by Src-mediated tyrosine phosphorylation. Based upon data demonstrating reduced CTTN mRNA levels in the lungs of smokers compared to non-smokers, we hypothesized a functional role for CTTN in CS-induced mitochondrial ROS generation and apoptosis in lung EC. Exposure of cultured human lung EC to CS condensate (CSC) led to the rearrangement of the actin cytoskeleton and increased CTTN tyrosine phosphorylation (within hours). Exposure to CS significantly increased EC mitochondrial ROS generation and EC apoptosis. The functional role of CTTN in these CSC-induced EC responses was explored using cortactin siRNA to reduce its expression, and by using a blocking peptide for the CTTN SH3 domain, which is critical to cytoskeletal interactions. CTTN siRNA or blockade of its SH3 domain resulted in significantly increased EC mitochondrial ROS and apoptosis and augmented CSC-induced effects. Exposure of lung EC to e-cigarette condensate demonstrated similar results, with CTTN siRNA or SH3 domain blocking peptide increasing lung EC apoptosis. These data demonstrate a novel role for CTTN in modulating lung EC apoptosis induced by CS or e-cigarettes potentially providing new insights into COPD pathogenesis.

Heat-not-burn tobacco (IQOS), oral fibroblasts and keratinocytes: cytotoxicity, morphological analysis, apoptosis and cellular cycle. An in vitro study

OBJECTIVES

The aim of this work is to investigate the biological effects of IQOS smoking on human gingival fibroblasts and human keratinocytes analysing cell viability, morphology, migration, apoptosis and cell cycle.

BACKGROUND

Electronic cigarettes and tobacco heating systems have been marketed to reduce smoking damages caused by combustion.

METHODS

Human gingival fibroblasts and human keratinocytes viability was determined by a colorimetric assay measuring mitochondrial dehydrogenase activity (MTT assay); after an in vitro exposure of 24 h, cell morphology was analysed with scanning electron microscope and cell migration was tested by Scratch assay, a method to mimic the migration of the cells during wound healing in vivo. Apoptosis and cell cycle were analysed with flow cytometry, and the expression of related genes (p53, Bcl2, p16 and p21) was indagated using real-time polymerase chain reaction.

RESULTS

IQOS extracts increased both cell viability (23%-41% with fibroblasts and 30%-79% with keratinocytes) and migration. No morphological alterations were observed. IQOS extracts did not induced an increase in cell death, but rose the number of S- and G2/M-phase cells. IQOS extracts also significantly increased p53 expression by fibroblasts (undiluted and 6.25% dilution, 2- and 3.6-fold higher, respectively) and reduced both Bcl2 (about two- and fivefold, respectively) and p21 expressions (about twofold with both extracts), while on keratinocytes both undiluted and 6.25% dilution extracts increased Bcl2 expression (about four- and threefold higher, respectively) and reduced p53 expression (about two- and fivefold, respectively).

CONCLUSION

IQOS smoke seemed to induce proliferation as highlighted by a viability assay, and migration and cell cycle analysis. The increased cell proliferation induced by IQOS devices must be carefully investigated for its possible clinical effects on oral cell populations.

Nicotine Exposure Via Electronic Cigarettes Significantly Impedes Biomechanical Healing Properties of Tendon Healing in a Rat Model

PURPOSE

To evaluate the biomechanical and histologic effects on Achilles tendon repair of inhaled combusted tobacco versus nicotine exposure via electronic cigarette versus a control group in a small-animal model (Sprague-Dawley rat).

METHODS

Fifty-four Sprague-Dawley rats were randomized into 3 groups: combusted tobacco, e-cigarettes, or control. Experimental rats were exposed to research cigarettes or e-cigarette vapor in a smoking chamber for 4 weeks. Surgical transection and repair of the Achilles tendon were then completed, followed by 2 additional weeks of exposure. Achilles tendons were harvested, and biomechanical tensile testing was performed. Histologic evaluation was completed, including hematoxylin-eosin staining, trichrome staining, and immunohistochemistry analysis for type I and type III collagen.

RESULTS

The control group showed the highest mean tensile load to failure, at 41.0 ± 10.4 N (range, 18.3-55.1 N); the cigarette cohort had the second highest mean, at 37.3 ± 11.1 N (range, 14.0-54.7 N); and finally, the vaping group had the lowest mean, at 32.3 ± 8.4 N (range, 17.8-45.1 N). One-way analysis of variance showed a significant difference in load to failure when comparing the control group with the e-cigarette group (P = .026). No statistical difference was detected between the control group and cigarette group (P = .35) or between the e-cigarette group and cigarette group (P = .23). Stiffness and qualitative histologic analysis showed no difference among groups.

CONCLUSIONS

This investigation shows that in a rat model, nicotine exposure via e-cigarette significantly impedes the biomechanical healing properties of Achilles tendon surgical repair.

CLINICAL RELEVANCE

The results indicate that although e-cigarettes are often used as a perceived "safer" alternative to smoking, their use may have a detrimental effect on tendon load to failure.

Anethole induces anti-oral cancer activity by triggering apoptosis, autophagy and oxidative stress and by modulation of multiple signaling pathways

Oral cancer is one of the major public health problems. The aim of this study was to evaluate the effects of anethole, 1-methoxy-4-[(E)-1-propenyl]-benzene, on growth and apoptosis of oral tumor cells, and to identify the signaling pathways involved in its interaction with these cancer cells. Cancer gingival cells (Ca9-22) were treated with different concentrations of anethole. Cell proliferation and cytotoxic effects were measured by MTT and LDH assays. Cell death, autophagy and oxidative stress markers were assessed by flow cytometry while cell migration was determined by a healing capacity assay. The effect of anethole on apoptotic and pro-carcinogenic signaling pathways proteins was assessed by immunoblotting. Our results showed that anethole selectively and in a dose-dependent manner decreases the cell proliferation rate, and conversely induces toxicity and apoptosis in oral cancer cells. This killing effect was mediated mainly through NF-κB, MAPKinases, Wnt, caspase 3, 9 and PARP1 pathways. Anethole showed an ability to induce autophagy, decrease reactive oxygen species (ROS) production and increased intracellular glutathione (GSH) activity. Finally, anethole treatment inhibits the expression of oncogenes (cyclin D1) and up-regulated cyclin-dependent kinase inhibitor (p21^WAF1), increases the expression of p53 gene, but inhibits the epithelial-mesenchymal transition markers. These results indicate that anethole could be a potential molecule for the therapy of oral cancer.

Effect of Dermaseptin S4 on C. albicans Growth and EAP1 and HWP1 Gene Expression

Increasing resistance and changes in the spectrum of Candida infections have generated considerable interest in the development of new antifungal molecules. The use of antimicrobial peptides (AMPs) appears to be a promising approach. Frog skin AMPs (such as dermaseptins) have shown antimicrobial activity against several pathogens. In this study, we aimed to test the antimicrobial efficacy of dermaseptin S4 (DS4) against C. albicans. We determined the minimal inhibitory concentration (MIC) of DS4, and investigated the effects of the DS4 at low concentrations on human primary gingival fibroblasts. Additionally, we evaluated the effect of DS4 on C. albicans growth, form changes, and biofilm formation, as well as the expression of certain virulent genes. Our data show that DS4 completely inhibits C. albicans growth at a concentration of 32 μg/mL referring to the MIC of DS4. It should be noted that even with low concentrations (below 16 μg/mL), DS4 still have significant growth reduction of C. albicans, but were not toxic to human gingival fibroblasts. DS4 inhibited the transition from yeast to hyphae, and decreased the biofilm formation by reducing the biofilm mass weight. Surface morphological changes in the yeast cell membrane were observed following exposure to DS4. The gene expression analyses revealed that DS4 significantly decreased the expression of EAP1 and HWP1 genes. Overall results suggest the potential use of DS4 as an antifungal therapy to prevent C. albicans pathogenesis.

The curcumin analog (PAC) suppressed cell survival and induced apoptosis and autophagy in oral cancer cells

PAC (3,5-Bis (4-hydroxy-3-methoxybenzylidene)-N-methyl-4-piperidone), a novel bioactive curcumin analog, has been reported to have anticancer properties against various tumors. However, the anti-cancer effects of PAC on oral cavity squamous cell carcinoma were not studied yet. Our aim is to investigate the anti-oral cancer properties of PAC in vitro, and determine the molecular mechanisms underlying these effects. Viability assays including MTT and LDH were conducted to measure cell proliferation. Flow cytometry-based cytotoxicity assay was performed to detect autophagic cell death and oxidative stress markers. Western blotting was used for measuring protein expression/activation in apoptotic, autophagic and pro-carcinogenic cellular signaling pathways. We demonstrated that PAC preferentially and, in a dose, -dependent way kills oral cancer cells, but was not toxic to normal human gingival cells. PAC destabilizes cell-cycle distributions, inhibits the expression of oncogenes (cyclin D1) and that of cyclin-dependent kinase inhibitor (p21^WAF1) is upregulated, increases the expression of p53 gene, and inhibits epithelial-mesenchymal transition markers in oral cancer cells. The PAC effect involve various signaling pathways including NF-κB, MAPK, Wnt, caspase-3/9 and PARP1. Finally, PAC demonstrated ability to induce autophagy, decrease production of reactive oxygen species, increase intracellular glutathione (GSH) activity, and reduce mitochondrial membrane potential in oral cancer cells. In conclusion, PAC inhibits the proliferation and increases the apoptosis and autophagy and oxidative stress of oral cancer cells. These effects involve ERK1/2, p38/JNK, NF-κB and Wnt cellular signaling pathways. Overall, our study suggests the potential use of PAC to treat oral cancer.

An updated overview of e-cigarette impact on human health

The electronic cigarette (e-cigarette), for many considered as a safe alternative to conventional cigarettes, has revolutionised the tobacco industry in the last decades. In e-cigarettes, tobacco combustion is replaced by e-liquid heating, leading some manufacturers to propose that e-cigarettes have less harmful respiratory effects than tobacco consumption. Other innovative features such as the adjustment of nicotine content and the choice of pleasant flavours have won over many users. Nevertheless, the safety of e-cigarette consumption and its potential as a smoking cessation method remain controversial due to limited evidence. Moreover, it has been reported that the heating process itself can lead to the formation of new decomposition compounds of questionable toxicity. Numerous in vivo and in vitro studies have been performed to better understand the impact of these new inhalable compounds on human health. Results of toxicological analyses suggest that e-cigarettes can be safer than conventional cigarettes, although harmful effects from short-term e-cigarette use have been described. Worryingly, the potential long-term effects of e-cigarette consumption have been scarcely investigated. In this review, we take stock of the main findings in this field and their consequences for human health including coronavirus disease 2019 (COVID-19).

Smoking and the patient with a complex lower limb injury

Smoking is known to increase the risk of peri-operative complications in Orthoplastic surgery by impairing bone and wound healing. The effects of nicotine replacement therapies (NRTs) and electronic cigarettes (e-cigarettes) has been less well established. Previous reviews have examined the relationship between smoking and bone and wound healing separately. This review provides surgeons with a comprehensive and contemporaneous account of how smoking in all forms interacts with all aspects of complex lower limb trauma. We provide a guide for surgeons to refer to during the consent process to enable them to tailor information towards smokers in such a way that the patient may understand the risks involved with their surgical treatment. We update the literature with recently discovered methods of monitoring and treating the troublesome complications that occur more commonly in smokers effected by trauma.

Electronic Cigarettes and Oral Health

Novel nicotine products, particularly electronic cigarettes (e-cigarettes), have become increasingly popular over the past decade. E-cigarettes are sometimes regarded as a less harmful alternative to tobacco smoking, and there is some evidence of their potential role as a smoking cessation aid. However, there are concerns about their health consequences, particularly in users who are not tobacco smokers, and also when used long term. Given the mode of delivery of these products, there is potential for oral health consequences. Over the past few years, there have been an increasing number of studies conducted to explore their oral health effects. In vitro studies have reported a range of cellular effects, but these are much less pronounced than those resulting from exposure to tobacco smoke. Microbiological studies have indicated that e-cigarette users have a distinct microbiome, and there is some indication this may be more pathogenic compared to nonusers. Evidence of oral health effects from clinical trials is still limited, and most studies to date have been small in scale and usually cross-sectional in design. Epidemiological studies highlight concerns over oral dryness, irritation, and gingival diseases. Interpreting data from e-cigarette studies is challenging, given the different populations that have been investigated and the continual emergence of new products. Overall, studies reveal potential oral health harms, underscoring the importance of efforts to reduce use in nonsmokers. However, in smokers who are using e-cigarettes as an aid to help them quit, the benefits of quitting tobacco smoking may outweigh any negative oral health impacts of e-cigarette use, particularly in the short term. Future research is needed to understand the clinical significance of some of the biological changes observed by following different cohorts of users longitudinally in carefully designed clinical studies and pragmatic trials supported by high-quality in vitro studies.

E-cigarette aerosol induced cytotoxicity, DNA damages and late apoptosis in dynamically exposed A549 cells

In this study, the acute toxicological impacts associated with electronic cigarettes consumption were determined using a novel dynamic exposure methodology. The methodology was deployed to test various e-cigarette generated aerosols in A549 cell cultures. The e-liquid chemical profiling was achieved using GC-MS analysis while toxicity of diluted e-liquids aerosols was reported using numerous cytotoxicity assays. The presented findings pointed to acute aerosol exposure (thirty puffs at 40 W of power and higher) inducing significant cytotoxic, genotoxic, and apoptotic induction in exposed cells. These findings highlighted the significant risks posed by e-cigarette usage. The proposed methodology proved to be a useful tool for future screening of e-liquids generated aerosols toxicity. Future research is needed to establish the chronic toxicity resulting from long-term e-cigarette consumption.

Comparative analysis of the impact of e-cigarette vapor and cigarette smoke on human gingival fibroblasts

Human gingival fibroblasts (HGF) play a vital role in wound healing, oral cancer, and are among the first cells being exposed to e-cigarette vapor (eCV) or cigarette smoke (CS) during inhalation. Although the cell-damaging effect of CS has been well studied, the effects of eCV on gingival cells are still unclear. The aim of this in vitro study was to compare the effects of eCV and CS on HGF in terms of proliferation, metabolic activity, cell death, and formation of reactive oxygen species (ROS). After 24 h cell numbers in CS-exposed cells in contrast to eCV-exposed cells were significantly decreased compared to the control. At later points in time, such differences could no longer be observed. Compared to the control, HGF stimulated with eCV showed a significantly higher metabolic activity 1 h, 24 h, and 48 h after exposure. 24 h after exposure, the metabolic activity was increased in both test groups. No caspase 3/7 activation nor significant differences in the amount of apoptosis/necrosis among the groups were seen. Only in CS-exposed cells ROS formation was increased at 1 h, 3 h, and 6 h after exposition. In conclusion, when compared to conventional CS, a less harmful effect of eCV on HGF can be assumed.

Effect of e-cigarettes on nasal epithelial cell growth, Ki67 expression, and pro-inflammatory cytokine secretion

OBJECTIVE

Upon use, e-cigarette aerosol comes in contact with various mucosal tissues, including the nasal epithelium, which may lead to nasal pathologies. We therefore assessed the effect of e-cigarettes on nasal epithelial cell and tissue behaviours.

METHODS

Human primary nasal epithelial cells and engineered 3D nasal mucosa tissues were exposed or not to either e-cigarette aerosol or standard cigarette smoke. We then evaluated cell viability and lactate dehydrogenase (LDH) activity. With the tissues analysed tissue structure, the expression of Ki67 proliferating marker, and the secretion of pro-inflammatory cytokines by the engineered nasal mucosa.

RESULTS

The nasal epithelial cells exposed to e-cigarettes displayed a larger cell size and a faint nucleus following exposure to e-cigarettes. This is supported by the increased levels of LDH activity following exposure to e-cigarettes, compared to that observed in the control. Tissues exposed to e-cigarette aerosol displayed a structural deregulation, with more large-sized cells, fewer Ki67-positive cells, and a reduced proliferation rate, compared to that observed in the non-exposed tissues. Cytokine measurements showed high levels of IL-6, IL-8, TNFα, and MCP-1, demonstrating that e-cigarettes activated pro-inflammatory cytokine responses.

CONCLUSION

E-cigarette aerosol showed adverse effects on nasal epithelial cells and nasal engineered mucosa tissue. These findings indicate that e-cigarettes could be a threat to nasal tissues and may impair the innate immune function of nasal epithelial cells.

Collecting e-cigarette aerosols for in vitro applications: A survey of the biomedical literature and opportunities to increase the value of submerged cell culture-based assessments

Electronic nicotine delivery systems (ENDS) are being developed as potentially reduced‐risk alternatives to the continued use of combustible tobacco products. Because of the widespread uptake of ENDS—in particular, e‐cigarettes—the biological effects, including the toxic potential, of their aerosols are under investigation. Preclinically, collection of such aerosols is a prerequisite for testing in submerged cell culture‐based in vitro assays; however, despite the growth in this research area, there is no apparent standardized collection method for this application. To this end, through an Institute for in vitro Sciences, Inc. workshop initiative, we surveyed the biomedical literature catalogued in PubMed® to map the types of methods hitherto used and reported publicly. From the 47 relevant publications retrieved, we identified seven distinct collection methods. Bubble‐through (with aqueous solvents) and Cambridge filter pad (CFP) (with polar solvents) collection were the most frequently cited methods (57% and 18%, respectively), while the five others (CFP + bubble‐through; condensation; cotton filters; settle‐upon; settle‐upon + dry) were cited less often (2–10%). Critically, the collected aerosol fractions were generally found to be only minimally characterized chemically, if at all. Furthermore, there was large heterogeneity among other experimental parameters (e.g., vaping regimen). Consequently, we recommend that more comprehensive research be conducted to identify the method(s) that produce the fraction(s) most representative of the native aerosol. We also endorse standardization of the aerosol generation process. These should be regarded as opportunities for increasing the value of in vitro assessments in relation to predicting effects on human health.

Collection of e‐cigarette aerosols is a prerequisite to enable testing in submerged culture‐based in vitro assays; however, there is no standardized method for this. Thus, we surveyed the biomedical literature to map the types of published methods. Bubble‐through and Cambridge filter pad methods were most common, although there was heterogeneity among other parameters, and moreover, the resulting fractions were only minimally characterized. Comprehensive research is required to identify the method(s) that produce the fraction(s) most representative of the native aerosol.

Interventions to prevent periodontal disease in tobacco-, alcohol-, and drug-dependent individuals

Substance abuse affects more than one sixth of the world's population. More importantly, the nature of the abuse and the type of addictive substances available to individuals is increasing exponentially. All substances with abusive potential impact both the human immuno-inflammatory system and oral microbial communities, and therefore play a critical role in the etiopathogenesis of periodontal diseases. Evidence strongly supports the efficacy of professionally delivered cessation counseling. Dentists, dental therapists, and hygienists are ideally placed to deliver this therapy, and to spearhead efforts to provide behavioral and pharmacologic support for cessation. The purpose of this review is to examine the biologic mechanisms underlying their role in disease causation, to understand the pharmacologic and behavioral basis for their habituation, and to investigate the efficacy of population-based and personalized interventions in prevention of periodontal disease.

The Evolving Landscape of e-Cigarettes: A Systematic Review of Recent Evidence

Smoking continues to be a burden to economies and health-care systems across the world. One proposed solution to the problem has been e-cigarettes; however, because they are a relatively new product in the market, little is known about their potential health impacts. Furthermore, e-cigarettes continue to evolve at a rapid rate, making it necessary to regularly review and summarize available studies. Although e-cigarettes are marketed as a smoking cessation tool by some manufacturers, the reality is that many nonsmokers, including youth, are using them. This review focuses on two major demographic groups (smokers and nonsmokers) and evaluates the most recent data (early 2017 to mid 2019) regarding the potential health effects of e-cigarettes. We assessed peer-reviewed studies on the health impacts of e-cigarettes, with a particular focus on common questions asked by policy makers, clinicians, and scientists: (1) What are the effects of e-cigarettes compared with air/not smoking?; (2) Is there any direct evidence of harm or benefit to humans?; (3) Is there a risk from secondhand exposure?; (4) What are the risks and/or benefits of e-cigarettes compared with tobacco cigarette use?; (5) Are there risks or benefits to specific populations (eg, people with COPD or asthma, pregnant women [and their offspring])?; (6) What are the effects of flavoring chemicals?; (7) What are the effects of including nicotine in e-liquids?; (8) How often is nicotine concentration labeling incorrect?; and (9) What are the risks when e-cigarettes explode?

Electronic Nicotine Delivery Systems (ENDS) and Their Relevance in Oral Health

The number and popularity of electronic nicotine delivery systems (ENDS) and especially e-cigarettes (e-cigs) have been increasing in the last decade. Although ENDS owe their popularity to excluding the harmful chemicals that are present in tobacco smoke, there is a debate whether they are safe, regulated, and as harmless as they are assumed to be and have potential unknown long-term effects. Involvement of cigarette smoking to the progression of periodontal diseases, other adverse oral health outcomes, and its detrimental effects to oral health are well-described. ENDS producer companies claim that these products can improve oral health by providing alternatives to smoking. However, the effect of e-cigs on oral health is not fully understood and is still debated among many scientists and clinicians. The number of studies addressing the potential toxic effect of ENDS or e-cig aerosol on oral cells is limited along with the clinical studies which are still preliminary, and their sample size is limited. The long-term effects of inhaled aerosols and the potential synergistic effect of the e-cigs components are not known. It is essential and of utmost importance to determine whether exposure to ENDS aerosol contributes to the progression of periodontal diseases and how it affects periodontal ligament and gingival cells which are believed to be its first targets. This review briefly summarizes the available evidence about the effects of e-cigs on periodontal health including several pathophysiological events, such as oxidative stress, DNA damage, inflammation, cellular senescence, dysregulated repair, and periodontal diseases.

Comparison of the subgingival temperature of smokers and nonsmokers in healthy and diseased sites of gingiva in association with sublingual body temperature

BACKGROUND

To compare the subgingival temperature in healthy and diseased sites of gingiva in smokers and non-smokers using a modified digital thermometer. To also find whether subgingival temperature measurements can be used as reliable indicator of periodontal disease activity.

MATERIALS AND METHODS

Participants for this study comprised 50 males, 25 smokers and 25 non-smokers with mild to moderate periodontitis, aged 25-40 years and had four maxillary incisor teeth (12, 11, 21, 22) intact. For each participant, six sites around each tooth were examined. Hence, a total of 24 sites for each participant were examined. The clinical parameters used were probing pocket depth and gingival bleeding index.

RESULTS

Sublingual and subgingival temperature was found to be warmer in smokers compared to non-smokers. Subgingival temperature was more in diseased sites than healthy sites in both smokers and non-smokers. The mean temperature differential of diseased sites in smokers was more compared to non-smokers. Mean probing pocket depth was higher in smokers, but bleeding sites were less.

CONCLUSION

Subgingival temperature measurement was found to be a good indicator of periodontal disease activity.

Immunological and pathological effects of electronic cigarettes

Electronic cigarettes (E-cigarettes) are considered a preferable alternative to conventional cigarettes due to the lack of combustion and the absence of tobacco-specific toxicants. E-cigarettes have rapidly gained in popularity in recent years amongst both existing smokers and previous non-smokers. However, a growing literature demonstrates that E-cigarettes are not as safe as generally believed. Here, we discuss the immunological, and other, deleterious effects of E-cigarettes on a variety of cell types and host defence mechanisms in humans and in murine models. We review not only the effects of complete E-cigarette liquids, but also each of the main components-nicotine, humectants and flavourings. This MiniReview thus highlights the possible role of E-cigarettes in the pathogenesis of disease and raises awareness of the potential harm that E-cigarettes may cause.

E-Cigarettes Increase Candida albicans Growth and Modulate its Interaction with Gingival Epithelial Cells

Electronic cigarette (e-cigarette) vapor comes in contact with the different constituents of the oral cavity, including such microorganisms as Candida albicans. We examined the impact of e-cigarettes on C. albicans growth and expression of different virulent genes, such as secreted aspartic proteases (SAPs), and the effect of e-cigarette vapor-exposed C. albicans on gingival epithelial cell morphology, growth, and lactate dehydrogenase (LDH) activity. An increase in C. albicans growth was observed with nicotine-rich e-cigarettes compared with non-exposed cultures. Following exposure to e-cigarette vapor, C. albicans produced high levels of chitin. E-cigarettes also increased C. albicans hyphal length and the expression of SAP2, SAP3, and SAP9 genes. When in contact with gingival epithelial cells, e-cigarette-exposed C. albicans adhered better to epithelial cells than the control. Indirect contact between e-cigarette-exposed C. albicans and gingival epithelial cells led to epithelial cell differentiation, reduced cell growth, and increased LDH activity. Overall, results indicate that e-cigarettes may interact with C. albicans to promote their pathogenesis, which may increase the risk of oral candidiasis in e-cigarette users.