Characterization and In Vivo Assay of Allantoin-Enriched Pectin Hydrogel for the Treatment of Skin Wounds.

This work describes a liquid allantoin-enriched pectin hydrogel with hydrophilic behavior that is supported by the presence of functional groups related to healing efficacy. A topical study shows the effect of the hydrogel application on surgically induced skin wound healing in a rat model. Contact angle measurements confirm hydrophilic behavior (11.37°), while Fourier-transform infrared spectroscopy indicates the presence of functional groups related to the healing effectiveness (carboxylic acid and amine groups). Allantoin is distributed on the surface and inside the amorphous pectin hydrogel surrounded by a heterogeneous distribution of pores. This promotes wound drying with better interaction between the hydrogel and cells involved in the wound healing process. An experimental study with female Wistar rats indicates that the hydrogel improves wound contraction, reducing around 71.43% of the total healing time and reaching total wound closure in 15 days.

Anti-Adherence and Antimicrobial Activities of Silver Nanoparticles against Serotypes C and K of Streptococcus mutans on Orthodontic Appliances.

Background and Objectives: Streptococcus mutans (S. mutans) is the main microorganism associated with the presence of dental caries and specific serotypes of this bacteria have been related to several systemic diseases limiting general health. In orthodontics, white spot lesions (WSL), represent a great challenge for clinicians due to the great fluctuation of their prevalence and incidence during conventional orthodontic treatments. Although silver nanoparticles (AgNP) have been demonstrated to have great antimicrobial properties in several microorganisms, including S. mutans bacteria, there is no available information about anti adherence and antimicrobial properties of AgNP exposed to two of the most relevant serotypes of S. mutans adhered on orthodontic materials used for conventional therapeutics. The objective of this study was to determine anti-adherence and antimicrobial levels of AgNP against serotypes c and k of S. mutans on conventional orthodontic appliances. Materials and Methods: An AgNP solution was prepared and characterized using dispersion light scattering (DLS) and transmission electron microscopy (TEM). Antimicrobial and anti-adherence activities of AgNP were determined using minimal inhibitory concentrations (MIC) and bacterial adherence testing against serotypes c and k of S. mutans clinically isolated and confirmed by PCR assay. Results: The prepared AgNP had spherical shapes with a good size distribution (29.3 ± 0.7 nm) with negative and well-defined electrical charges (−36.5 ± 5.7 mV). AgNP had good bacterial growth (55.7 ± 19.3 µg/mL for serotype c, and 111.4 ± 38.6 µg/mL for serotype k) and adherence inhibitions for all bacterial strains and orthodontic wires (p < 0.05). The serotype k showed statistically the highest microbial adherence (p < 0.05). The SS wires promoted more bacterial adhesion (149.0 ± 253.6 UFC/mL × 104) than CuNiTi (3.3 ± 6.0 UFC/mL × 104) and NiTi (101.1 ± 108.5 UFC/mL × 104) arches. SEM analysis suggests CuNiTi wires demonstrated better topographical conditions for bacterial adherence while AFM evaluation determined cell wall irregularities in bacterial cells exposed to AgNP. Conclusions: This study suggests the widespread use of AgNP as a potential anti-adherent and antimicrobial agent for the prevention of WSL during conventional orthodontic therapies and, collaterally, other systemic diseases.

Apoptosis and apoptotic pathway in actinic prurigo by immunohistochemistry.

BACKGROUND: Actinic prurigo (AP) is an idiopathic photodermatosis, this entity requires exposure to UV-B and -A to develop lesions. Apoptosis is a physiological death program that can be initiated by a permanently active mechanism (extrinsic pathway) or irreparable damage (intrinsic pathway). MATERIAL AND METHODS: Descriptive study, the sample size comprised 64 paraffin blocks of tissue with a diagnosis of AP. In H&E-stained slides, the diagnosis of AP was corroborated, and 1-µm-thick sections were processed for immunohistochemistry (IHC). A database was constructed with SPSS version 20, Inc., Chicago, IL, USA, and descriptive statistics were analyzed by X2 test and comparison of means. RESULTS: A total of 64 cases were processed, of which 40 (62.5%) were cheilitis AP and 24 (37.5%) were AP in the skin. Of the 40 cheilitis samples, 27 were positive for Bcl-2 and caspase 3 (67.5%), p53 was expressed in 30 (75%). Of the skin lesions, p53 and caspase 3 were expressed in 18 of 24 cases (75%), and 13 were positive for Bcl-2 (54%). CONCLUSIONS: We propose that apoptosis is the last step in the type IV subtype a-b hypersensitivity response-activation of the intrinsic pathway indicates that external factors, such as UV-A and -B are the trigger.

Basal Cell Carcinoma in a Patient With Brooke-Spiegler Syndrome.

A 46-year-old woman was diagnosed with Brooke-Spiegler syndrome (BSS) with lesions on her head, predominantly on the center of her face, auricles, and scalp. The facial lesions were polymorphic, pale, confluent, skin-colored, and papular, whereas the scalpel lesions appeared as erythematous and violet lumps that varied in size (Figure 1A, B).

Actinic Prurigo.

Actinic prurigo is an idiopathic photodermatosis that affects the skin, as well as the labial and conjunctival mucosa in indigenous and mestizo populations of Latin America. It starts predominantly in childhood, has a chronic course, and is exacerbated with solar exposure. Little is known of its pathophysiology, including the known mechanisms of the participation of HLA-DR4 and an abnormal immunologic response with increase of T CD4+ lymphocytes. The presence of IgE, eosinophils, and mast cells suggests that it is a hypersensitivity reaction (likely type IVa or b). The diagnosis is clinical, and the presence of lymphoid follicles in the mucosal histopathologic study of mucosa is pathognomonic. The best available treatment to date is thalidomide, despite its secondary effects.

Life Satisfaction and Dental Visits in Adults Aged ≥50 Years and Living with Diabetes Mellitus: A Comparison between Urban and Rural Mexican.

Objective: To examine the association between low life satisfaction with past-year dental visits in a rural-urban national sample of 50-year-old Mexican adults with diabetes mellitus (DM). Methods: Data are drawn from the Mexican Health and Aging Study (MHAS), a cross-sectional study conducted in 2018 involving 3,592 older adults aged 50 years and older and living in urban and rural areas in Mexico. Life satisfaction was measured using the Satisfaction with Life Scale (SWLS) and past-year dental visits dichotomized as none and ≥1 dental visits. The Poisson regression analyses were used to assess the association, adjusting for confounders. Results: 62.9% were women, mean age was 65.5 (±9.6), and 16.5% lived in a rural area, while the female subjects continue to present a higher probability of visiting a dentist (PR = 1.28 (95% CI 1.08-1.51)). In terms of age, the ≥70-year group presented 28% lower possibility of visiting a dentist (PR = 0.72 (95% CI 0.60-0.86)). The interaction showed that adults ≥50 years who reside in a rural area and have low life satisfaction were 40% less likely to have visited a dentist in the last year (PR = 0.60 (95% CI 0.37-0.98)) than adults ≥50 years who reside in an urban area and have high life satisfaction. Conclusions: The present study highlights the association between low life satisfaction and past-year dental visits in rural populations. Therefore, rurality should be considered a possible confounder in analysis of life satisfaction in the older adult population.

Use or abuse of antibiotics as prophylactic therapy in oral surgery: A systematic review.

BACKGROUD: Antibiotics are a type of medication routinely prescribed by dental professionals; however, it is very common that the administration is not justified. Around 15% of dentists admit that they have administered antibiotics unnecessarily more than once a week. The objective of this project is to identify the effectiveness of the use of antibiotics as prophylactic therapy in oral surgery, and to carry out an analysis of the alternatives to pharmacological therapy. METHODS: The search strategy was carried out in the PubMed, Scopus, and ScienceDirect databases. For study selection, a first filter was carried out by title and abstract, which mentioned the use of prophylactic antibiotics in some type of oral surgery. To establish the risk of bias, the JBI Critical Appraisal Checklist for Randomized Controlled Trials was utilized. RESULTS: The type of antibiotics most prescribed as prophylactic therapy were beta-lactams, which were indicated in 100% of the studies. Penicillins predominated, observing amoxicillin as the most indicated drug in 54.1% of the studies (n = 13) followed by the use of amoxicillin in conjunction with clavulanic acid in 33.3% of the studies (n = 8). Of the 21 studies included, 17 mention that there is insufficient evidence to support the use of antibiotics as prophylactic therapy in patients who will undergo some type of oral surgery. CONCLUSIONS: Without a doubt, the biggest challenge is to develop academic update strategies aimed at dentists with active clinical practice and dental students from educational and government institutions to provide updated information about the correct use of prescription drugs.

Bactericidal Activity of Silver Nanoparticles on Oral Biofilms Related to Patients with and without Periodontal Disease.

BACKGROUND AND OBJECTIVES: Periodontal disease (PD) is a multifactorial oral disease regularly caused by bacterial biofilms. Silver nanoparticles (AgNP) have offered good antimicrobial activity; moreover, there is no available scientific information related to their antimicrobial effects in biofilms from patients with PD. This study reports the bactericidal activity of AgNP against oral biofilms related to PD. MATERIALS AND METHODS: AgNP of two average particle sizes were prepared and characterized. Sixty biofilms were collected from patients with (30 subjects) and without PD (30 subjects). Minimal inhibitory concentrations of AgNP were calculated and the distribution of bacterial species was defined by polymerase chain reaction. RESULTS: Well-dispersed sizes of AgNP were obtained (5.4 ± 1.3 and 17.5 ± 3.4 nm) with an adequate electrical stability (-38.2 ± 5.8 and -32.6 ± 5.4 mV, respectively). AgNP showed antimicrobial activities for all oral samples; however, the smaller AgNP had significantly the most increased bactericidal effects (71.7 ± 39.1 µg/mL). The most resistant bacteria were found in biofilms from PD subjects (p < 0.05). P. gingivalis, T. denticola, and T. forsythia were present in all PD biofilms (100%). CONCLUSIONS: The AgNP showed efficient bactericidal properties as an alternative therapy for the control or progression of PD.

Stem cells as an option for the treatment of COVID-19.

The application of stem cells is among the many strategies currently available for the treatment of multiple diseases. Stem cells are characterized as undifferentiated cells that have the ability to differentiate towards multiple lineages and self-renewal, among other attributes. Since the first umbilical cord stem cell transplant for the treatment of Fanconi anemia, the use of stem cells for the treatment of multiple diseases, including coronavirus disease 2019, has increased, showing promising results that require evaluation through research studies that include a longer follow-up time. Therefore, the main objective of this Letter is to provide an update on the use of stem cells in the treatment of severe acute respiratory syndrome coronavirus 2, as well as identify the main challenges and limitations presented by this type of therapy.

Tumor invasion front in oral squamous cell carcinoma.

Oral squamous cell carcinoma is a neoplasm that originates from the epithelial mucosa. It is usually more frequent between the fifth and sixth decades of life, and more than 90% of carcinomas of the oral cavity are squamous cell carcinoma. It is an invasive neoplasia with a significant recurrence rate; 40% of patients present with metastases in the cervical lymph nodes at the time of diagnosis. The tumor invasion front is a characteristic of tumor growth, which can be infiltrative or noninvasive. The histopathological parameters examined include the number of mitoses, depth of the tumor, invasion pattern, degree of keratinization, and nuclear pleomorphism. For the pathologist, these parameters are routinely evaluated but are not reported to the treating physician in all cases, which we consider to be useful information when determining the therapeutic route.

Antimicrobial resistance in odontogenic infections: A protocol for systematic review.

BACKGROUND: It is estimated that up to 90% of head and neck infections have an odontogenic origin, which are considered among the most common in the oral cavity and maxillofacial region. Bacterial resistance has been 1 of the main problems related to the treatment of this type of infection in recent years. The frequency of this resistance is increasing, which is mainly due to patient self-medication and the mutations that bacteria present. Therefore, the objective of this study is to analyze the antimicrobial resistance of antibiotics commonly administered for the treatment of odontogenic infections. METHOD: To carry out the study, PubMed, ScienceDirect, and Scopus databases were reviewed using the keywords "odontogenic infection", "pharmacological treatment", and "microbial resistance. Studies whose main objective was the pharmacological treatment of odontogenic infections were selected. Exclusions were review-type studies, systematic reviews, or in vitro or animal model studies. For the analysis of risk of bias, the Checklist for Analytical Cross-Sectional Studies of the Joanna Briggs Institute was used. The search and analysis of the studies was carried out by 2 researchers independently. RESULTS: A total of 13 studies were included in this review. The mean age was 39.6 years; the location of the infection in the study subjects was in the submandibular and vestibular spaces; there were periodontal, periapical, and dentoalveolar lesions; the main microorganisms identified were Streptococcus, Staphylococcus, Prevotella, Peptostreptococcus, Clostridium, and Klebsiella; and finally, the main microorganisms identified for bacterial resistance were penicillin, clindamycin and amoxicillin. CONCLUSION: The health professional is obliged to update their knowledge to avoid such antibiotic resistance and thus provide better patient care.

General Labor Well-Being in Latin American Dentists during the COVID-19 Pandemic.

This study aimed to determine the general labor well-being of Latin American dentists according to sociodemographic characteristics during the COVID-19 pandemic. A cross-sectional study was conducted in a final sample of 2214 participants from 11 countries. A validated online questionnaire on general work well-being was used (data collection period from 1 June to 10 July 2021), containing two dimensions: psychosocial well-being and collateral effects. The sociodemographic characteristics of the dentists and their perception of the economic impact of the pandemic were also recorded. A multivariate linear regression analysis was performed (hierarchical regression model) to evaluate the joint effect of the explanatory variables on labor well-being and the changes in the variance between each model. A score of psychosocial well-being of 233.6 + 40.2 and collateral effects of 45 + 20.1 was found. Psychosocial well-being was associated with sex, country of origin, academic training achieved, type of dental activity, and perceived impact during the pandemic (p < 0.05). Somatization was frequently manifested through back pain (88.2%) and muscular tensions (87.2%). Women, those who worked 41 or more hours and had between 1 to 15 years of professional experience presented a greater collateral effect (p < 0.001). The impact of the COVID-19 pandemic a year and a half after it began on the labor well-being of Latin American dentists was evidenced with important interactions with social characteristics.

Value of the toluidine blue test as an aid to determine the biopsy site in actinic prurigo cheilitis.

Actinic prurigo (AP) is a type of photodermatosis that primarily affects the Latin American mestizo population. Histologically, AP cheilitis exhibits acanthosis with spongiosis and vacuolation of the basal cell layer overlying a dense lymphocytic inflammatory infiltrate that forms well-defined lymphoid follicles. Toluidine blue is a thiazide, acidophilic, and metachromatic dye used in vivo to selectively stain the acidic components of tissues such as sulfates, carboxylates, and phosphate radicals that are incorporated into DNA and RNA. It is necessary to develop a method that allows detecting, on clinical grounds the area of the lesion in which it is more feasible to find such structures. Thus to increase the sensitivity of the biopsy, in AP cheilitis to accurately identify where the lymphoid follicles reside, based on the higher concentration of DNA in such structures and thus confirm the diagnosis. In this study, staining was positive in 85% of patients with AP cheilitis, in 14 of whom 82% lymphoid follicles were observed by histopathology. One of the pathologist's problems in establishing the diagnosis of AP is that the main histopathological characteristics are not always identified in the submitted samples because it is not easy to clinically identify the most representative site of the lesion selected for performing a biopsy. Based on our results, we propose using toluidine blue as an auxiliary method to choose a tissue sample to facilitate the diagnosis and allow clinicians to make clinical correlations between the histopathological and therapeutic findings.

Stem Cells as a Model of Study of SARS-CoV-2 and COVID-19: A Systematic Review of the Literature.

BACKGROUND: The SARS-CoV-2 virus is the cause of the latest pandemic of the 21st century; it is responsible for the development of COVID-19. Within the multiple study models for both the biology and the treatment of SARS-CoV-2, the use of stem cells has been proposed because of their ability to increase the immune response and to repair tissue. Therefore, the objective of this review is to evaluate the role of stem cells against SARS-CoV-2 and COVID-19 in order to identify their potential as a study model and as a possible therapeutic source against tissue damage caused by this virus. Therefore, the following research question was established: What is the role of stem cells in the study of SARS-CoV-2 and the treatment of COVID-19? MATERIALS AND METHODS: A search was carried out in the electronic databases of PUBMED, Scopus, and ScienceDirect. The following keywords were used: "SARS-CoV-2," "COVID-19," and "STEM CELL," plus independent search strategies with the Boolean operators "OR" and "AND." The identified reports were those whose main objective was the study of stem cells in relation to SARS-CoV-2 or COVID-19. For the development of this study, the following inclusion criteria were taken into account: studies whose main objective was the study of stem cells in relation to SARS-CoV-2 or COVID-19 and clinical case studies, case reports, clinical trials, pilot studies, in vitro, or in vivo studies. For assessment of the risk of bias for in vitro studies, the SciRAP tool was used. The data collected for each type of study, clinical or in vitro, were analyzed with descriptive statistics using the SPSS V.22 program. RESULTS: Of the total of studies included (n = 39), 22 corresponded to in vitro investigations and 17 to human studies (clinical cases (n = 9), case series (n = 2), pilot clinical trials (n = 5), clinical trials (n = 1)). In vitro studies that induced pluripotent stem cells were the most used (n = 12), and in clinical studies, the umbilical stem cells derived were the most reported (n = 11). The mean age of the study subjects was 58.3 years. After the application of stem cell therapy, the follow-up period was 8 days minimum and 90 days maximum. Discussion. The mechanism by which the virus enters the cell is through protein "S," located on the surface of the membrane, by recognizing the ACE2 receptor located on the target cell. The evidence that the expression of ACE2 and TMPRSS2 in stem cells indicates that stem cells from bone marrow and amniotic fluid have very little expression. This shows that stem cell has a low risk of infection with SARS-CoV-2. CONCLUSION: The use of stem cells is a highly relevant therapeutic option. It has been shown in both in vitro studies and clinical trials that it counteracts the excessive secretion of cytokines. There are even more studies that focus on long-term follow-up; thus, the potential for major side effects can be analyzed more clearly. Finally, the ethical use of stem cells from fetal or infant origin needs to be regulated. The study was registered in PROSPERO (no. CRD42021229038). The limitations of the study were because of the methodology employed, the sample was not very large, and the follow-up period of the clinical studies was relatively short.

Association between sociodemographic factors and noncavitated and cavitated caries lesions in 8- to 12-year-old Mexican schoolchildren.

ABSTRACT: The aim of this study was to evaluate the association between sociodemographic factors and noncavitated and cavitated caries lesions in Mexican schoolchildren.This cross-sectional study was conducted in 2020 on 8-to-12-year-old schoolchildren of different socioeconomic status (SES). The caries was evaluated using ICDAS II, SES was evaluated using three categories---a high, middle, or low-income level---of the CONAPO. Multinomial logistic regression analyses were performed in order to ascertain the associations between socioeconomic factors and noncavitated and cavitated caries lesions.The prevalence of noncavitated lesions was 38.0% and cavitated lesions was 43.4% in permanent dentition. In all the samples, 50.6% of schoolchildren had poor oral hygiene. About 52.5% of the mothers and 64.7% of the fathers had less than 9 years of education. Schoolchildren with a low-income level have more cavitated lesions (ICDAS II 4-6) than schoolchildren with high-income level (56.3% vs 15.8%, P = .009). The multinomial logistic regression models showed that mother's level of education <9 years and low-income level were significantly associated with cavitated caries lesions (ICDAS II 4-6), [odds ratio = 1.79 (1.17 - 2.75); P = .007], [OR = 2.21 (1.23 - 3.97); P = .008], respectively. The socioeconomic level was not associated with noncavitated caries lesions (ICDAS II 1-3).An association was found between the presence of cavitated caries lesions and the subject's mother's level of education and a low-income level. Socioeconomic factors were found to be associated with inequalities in caries distribution in the age group studied.

Characterization and Topical Study of Aloe Vera Hydrogel on Wound-Healing Process.

Wound healing is fundamental to restore the tissue integrity. A topical study of the influence of Aloe vera hydrogel, formulated with 1,2-propanediol (propanediol) and triethanolamine (TEA), on the skin wound-healing process was investigated in female Wistar rats. FTIR spectroscopy confirms the presence of carboxylic acid and methyl ester carboxylate groups related with important compounds that confer the hydrogel a good interaction with proteins and growth factors. SEM images show a microstructure and micro-roughness that promote a good adhesion to the wound. Therefore, the swelling kinetics and the contact angle response contribute to the understanding of the in vivo results of the animal test. The results indicated that the Aloe vera hydrogel, prepared with propanediol and TEA, together with its superficial characteristics, improve its rapid penetration without drying out the treated tissue. This produced a positive influence on inflammation, angiogenesis, and wound contraction, reducing 29% the total healing time, reaching the total closure of the wound in 15 days.

COVID-19 and its manifestations in the oral cavity: A systematic review.

BACKGROUND: SARS-CoV-2 is the virus responsible for coronavirus disease-19 (COVID-19) disease, which has been shown to trigger multiple affectations. One of the first tissue areas to come into contact with the virus is the oral cavity, which develops various alterations. Hence, the objective of this systematic review was to identify the main signs and symptoms of this disease in the oral cavity, and the following research question was established: What are the main oral signs and symptoms in COVID-19-positive persons? METHODS: The electronic databases of PUBMED, SCOPUS, and SCIENCE DIRECT were analyzed, the keywords "ORAL DISEASES," "ORAL MANIFESTACTIONS," and "COVID-19" were used taking into account the following inclusion criteria: studies whose main objective was oral manifestations secondary to the confirmation of COVID-19, plus clinical cases, case series, and retrospective or prospective studies. For the assessment of the risk of bias the JBI Critical Appraisal Checklist for Case Series tool was used. RESULTS: A total of 18 studies were included, the most common initial signs/symptoms after contagion of SARS-CoV-2 were dysgeusia, dry mouth, and burning mouth, and the main signs/symptoms were the presence of ulcerative lesions, dysgeusia, and Candida albicans infections. CONCLUSIONS: It is very important to detect any alteration in the mucosa in patients with COVID-19 and to provide assertive treatment to avoid complications, and try to maintain adequate oral hygiene throughout the course of the disease to avoid the colonization of opportunistic microorganisms and to avoid complications both orally and systemically.

Preliminary Biocompatibility Tests of Poly-ε-Caprolactone/Silver Nanofibers in Wistar Rats.

Currently, nanotechnology is perceived as a promising science that produces materials with diverse unique properties at a nanometric scale. Biocompatibility tests of poly-ε-caprolactone nanofibers, embedded with silver nanoparticles manufactured by means of the electrospinning technique, were carried out in Wistar rats to be used as oral dressings for the eradication of bacteria. Solutions of 12.5, 25, 50 and 100 mM of silver nitrate were made using N-dimethylformamide (DMF) and tetrahydrofuran (THF) as reducing solvents with 8% of poly-ε-caprolactone (PCL) polymer. The solutions were electrospun, and the nanofibers obtained in the process were characterized by infrared spectroscopy, Raman spectroscopy, dark field optical microscopy, scanning electron microscopy and X-ray scattering spectroscopy. The nanofibers had an average diameter of 400 ± 100 nm. Once the characterization of the material was done, three implants of each concentration of the nanofibers were formed and placed in the subcutaneous tissue of the rats. Three experimental subjects were used, leaving the material in them for a length of two, four and six weeks, respectively. The rats showed good healing, with the lesions completely healed at four weeks after implantation. After that time, biopsies were taken, and histopathological sections were made to evaluate the inflammatory infiltrate. The tissues of the rats presented chronic inflammatory infiltrate composed mainly of lymphocytes and giant multinucleated cells. The material was rejected by the rats when a layer of collagen and fibroblasts was produced, coating the material, a process characteristic of a foreign body reaction.

Expression of MicroRNAs in Periodontal Disease: A Systematic Review.

INTRODUCTION: Periodontal disease (PD) is a chronic inflammation of the soft tissues that support the structure of the tooth, and miRNAs are highly dynamic molecules that participate in the regulation of gene expression interfering with multiple genetic targets. The dysregulation of the expression of miRNAs has been associated with different types of pathologies; therefore, they are excellent molecules to be studied as biomarkers. Material and Methods. A search was made in the electronic databases of PubMed, Scopus, and Science Direct. The following key words were used: "microRNAs," "miRNAs," "periodontal disease," "periodontitis," and "biomarker"; employee independent search strategies with the Boolean operators "OR" and "AND"; a further search of the references of the selected studies was performed to detect potential studies that met the selection criteria. The data recollected from each article were author, country, year of publication, sample size, type of sample used to identify miRNAs, methodology used to identify miRNAs, type of periodontal disease, and miRNAs identified. RESULTS: Of the 13 selected studies, 6 used gingival tissue as a sample for the identification of miRNAs, 3 used gingival fluid, 2 used saliva, 1 used serum, and another used periodontal tissue. Chronic periodontitis was the most studied periodontal disease in 9 of the 13 selected articles; 7 used microarrays as the main technique for the identification of miRNAs. qRT-PCR was the assay choice to validate the identified miRNAs. CONCLUSION: The main type of periodontal disease on which most studies are focused is chronic periodontitis, with the main miRNAs being hsa-miR-146a, hsa-miR-146b, hsa-miR-155, and hsa-miR-200. This systematic review is one of the first to carry out an analysis of the current role of miRNAs in PD as biomarkers.

Natural Film Based on Pectin and Allantoin for Wound Healing: Obtaining, Characterization, and Rat Model.

INTRODUCTION: In our days, several approaches reported the use of natural compounds in medical applications. Among them, pectin and allantoin are nontoxic, biocompatible, and biodegradable; however, its use for possible wound healing therapeutics is still limited. Pectin and allantoin have been applied in pharmaceutical industry and beauty cosmetic and could be also applied as scaffolds for tissue regeneration, wound healing, and so on. The aim of this study was to combine by the first time two natural ingredients to develop a new biomaterial to treat skin injuries in a rat model. METHODS: For the hydrogel development, new synthesis parameters were established for the obtaining of the film such as temperature, mixing velocity and time, and drying temperatures as well. To enrich the film, the allantoin concentrations were set at 90 wt% and 100 wt% of pectin used. By in vivo assay, films were tested in wound healing in female Wistar rats, 190 ± 10 g in weight and 2 months aged. RESULTS: The obtained films comprise 2 well-differentiated layers, one layer rich in allantoin, which will be the regenerative layer, and one rich in pectin, which will work as an antimicrobial and protective layer to the wound. These were characterized by swelling kinetics, Fourier transform of the infrared spectrum of absorption (FTIR) spectroscopy, and contact angle. The morphology and topography were determined by scanning electron microscopy (SEM) and confocal laser scanning microscopy (CLSM). In vivo assay showed remarkable reduce in a time period in a wound healing process when the film was used. The results show that the use of PA (Pectin-Allantoin) hydrogel reduces the total healing time by 25% approximately. CONCLUSIONS: Pectin-Allantoin (PA) film has potential use in medical applications as wound healing material promoting healthy tissue renewal.