Gelatin-Chitosan Hydrogel Biological, Antimicrobial and Mechanical Properties for Dental Applications.

Chitosan, a natural polysaccharide sourced from crustaceans and insects, is often used with hydrogels in wound care. Evaluating its cytotoxicity and antimicrobial properties is crucial for its potential use in dentistry. OBJECTIVE: To investigate the mechanical properties of gelatin hydrogels based on decaethylated chitosan and antimicrobial activity against Streptococcus mutans and their biological effects with stem cells from apical papilla (SCAPs). MATERIAL AND METHODS: Gelatin-chitosan hydrogels were synthesized at concentrations of 0%, 0.2% and 0.5%. Enzymatic and hydrolytic degradation, along with swelling capacity, was assessed. Fourier transform infrared spectroscopy (FTIR) analysis was employed to characterize the hydrogels. The interaction between hydrogels and SCAPs was examined through initial adhesion and cell proliferation at 24 and 48 h, using the Thiazolyl Blue Tetrazolium Bromide (MTT assay). The antimicrobial effect was evaluated using agar diffusion and a microdilution test against S. mutans. Uniaxial tensile strength (UTS) was also measured to assess the mechanical properties of the hydrogels. RESULTS: The hydrogels underwent hydrolytic and enzymatic degradation at 30, 220, 300 min and 15, 25, 30 min, respectively. Significantly, (p < 0.01) swelling capacity occurred at 20, 40, 30 min, respectively. Gelatin-chitosan hydrogels' functional groups were confirmed using vibrational pattern analysis. SCAPs proliferation corresponded to 24 h = 73 ± 2%, 82 ± 2%, 61 ± 6% and 48 h = 83 ± 11%, 86 ± 2%, 44 ± 2%, respectively. The bacterial survival of hydrogel interaction was found to be 96 ± 1%, 17 ± 1.5% (p < 0.01) and 1 ± 0.5% (p < 0.01), respectively. UTS showed enhanced (p < 0.05) mechanical properties with chitosan presence. CONCLUSION: Gelatin-chitosan hydrogels displayed favorable degradation, swelling capacity, mild dose-dependent cytotoxicity, significant proliferation with stem cells from apical papilla (SCAPs), substantial antimicrobial effects against S. mutans and enhanced mechanical properties. These findings highlight their potential applications as postoperative care dressings.

Cytotoxicity, Differentiation, and Biocompatibility of Root-End Filling: A Comprehensive Study.

Assessing the biocompatibility of endodontic root-end filling materials through cell line responses is both essential and of utmost importance. This study aimed to the cytotoxicity of the type of cell death through apoptosis and autophagy, and odontoblast cell-like differentiation effects of MTA, zinc oxide-eugenol, and two experimental Portland cements modified with bismuth (Portland Bi) and barium (Portland Ba) on primary cell cultures. Material and methods: The cells corresponded to human periodontal ligament and gingival fibroblasts (HPLF, HGF), human pulp cells (HPC), and human squamous carcinoma cells from three different patients (HSC-2, -3, -4). The cements were inoculcated in different concentrations for cytotoxicity evaluation, DNA fragmentation in electrophoresis, apoptosis caspase activation, and autophagy antigen reaction, odontoblast-like cells were differentiated and tested for mineral deposition. The data were subject to a non-parametric test. Results: All cements caused a dose-dependent reduction in cell viability. Contact with zinc oxide-eugenol induced neither DNA fragmentation nor apoptotic caspase-3 activation and autophagy inhibitors (3-methyladenine, bafilomycin). Portland Bi accelerated significantly (p < 0.05) the differentiation of odontoblast-like cells. Within the limitation of this study, it was concluded that Portland cement with bismuth exhibits cytocompatibility and promotes odontoblast-like cell differentiation. This research contributes valuable insights into biocompatibility, suggesting its potential use in endodontic repair and biomimetic remineralization.

Evaluation of the biological responses of silver nanoparticles synthesized using Pelargonium x hortorum extract.

Silver nanoparticles (AgNPs) are one of the widely studied nanomaterials for diverse biomedical applications, in particular, as antimicrobial agents to kill bacteria, fungi, and viruses. In this report, AgNPs were synthesized using a geranium (Pelargonium x hortorum) leaves extract and tested for their antimicrobial and cytotoxic activity and reactive oxygen species (ROS) production. Using green biosynthesis, the leaves extract was employed as a reducing and stabilizing agent. Synthesis parameters like reaction time and precursor (silver nitrate AgNO3) volume final were modified, and the products were tested against Streptococcus mutans. For the first time, the metabolomic analysis of extract, we have identified more than 50 metabolites. The UV-Vis analysis showed a peak ranging from 410-430 nm, and TEM confirmed their nearly spherical morphology for all NPs. The antimicrobial activity of the NPs revealed a minimum inhibitory concentration (MIC) of 10 µg mL-1. Concerning cytotoxicity, a dose-time-dependent effect was observed with a 50% cellular cytotoxicity concentration (CC50) of 4.51 µg mL-1 at 24 h. Interestingly, the cell nuclei were visualized using fluorescence microscopy, and no significant changes were observed. These results suggest that synthesized spherical AgNPs are promising potential candidates for medical applications.

Efficacy of Antineoplastic Nanocarriers on 3D Oral Cancer Spheroids.

BACKGROUND/AIM: Cancer is a leading cause of death worldwide. Conventional treatments as surgery, chemotherapy, radiotherapy, and combined therapies are commonly used. However, these therapies have several limitations and side effects. To address these issues, innovative research is being conducted on nanocarriers (NCs) functionalized with antineoplastic agents. These NCs aim to overcome limitations and improve patients' lives. However, before they can be used clinically, these NCs are primarily assessed on a lab scale to determine their efficacy. MATERIALS AND METHODS: A primary cell culture was established from a lymphoblastic neoplasm in the maxilla. After characterization, the cells were cultured in 2D to evaluate the dose-effect of nanoparticles (NPs), such as Zinc oxide (ZnO) and Magnesium oxide (MgO), as well as those of free drugs of 5-fluorouracil (5-FU) and cisplatin (Cis). Based on the results, a 3D spheroid culture was used for further study. Finally, the spheroids were histologically processed for immuno-morphological observation. RESULTS: To evaluate spheroid cell viability, we conducted an MTT assay. Treatment of cell spheroids with ZnONPs, 5-FU, and NPs conjugated with antitumor agents such as 5-FU-ZnO and Cis-ZnO decreased cell viability by >25%, >60% and >10% and <20% at a concentration of 0.06, 0.015 and 0.015 & 0.03 mg/ml, respectively. CONCLUSION: Nanoparticles conjugated with antitumor agents showed promising antineoplastic effects on both 2D and 3D cell cultures. However, the efficacy of the nanoparticles varied between the different models. This highlights the importance of selecting appropriate in vitro culture models for the evaluation of biomedical agents.

Decellularized Scaffolds of Nopal (Opuntia Ficus-indica) for Bioengineering in Regenerative Dentistry.

Opuntia Ficus-indica, or nopal, is traditionally used for its medicinal properties in Mexico. This study aims to decellularize and characterize nopal (Opuntia Ficus-indica) scaffolds, assess their degradation and the proliferation of hDPSC, and determine potential pro-inflammatory effects by assessing the expression of cyclooxygenase 1 and 2 (COX-1 and 2). The scaffolds were decellularized using a 0.5% sodium dodecyl sulfate (SDS) solution and confirmed by color, optical microscopy, and SEM. The degradation rates and mechanical properties of the scaffolds were determined by weight and solution absorbances using trypsin and PBS and tensile strength testing. Human dental pulp stem cells (hDPSCs) primary cells were used for scaffold-cell interaction and proliferation assays, as well as an MTT assay to determine proliferation. Proinflammatory protein expression of COX-I and -II was discovered by Western blot assay, and the cultures were induced into a pro-inflammatory state with interleukin 1-ß. The nopal scaffolds exhibited a porous structure with an average pore size of 252 ± 77 µm. The decellularized scaffolds showed a 57% reduction in weight loss during hydrolytic degradation and a 70% reduction during enzymatic degradation. There was no difference in tensile strengths between native and decellularized scaffolds (12.5 ± 1 and 11.8 ± 0.5 MPa). Furthermore, hDPSCs showed a significant increase in cell viability of 95% and 106% at 168 h for native and decellularized scaffolds, respectively. The combination of the scaffold and hDPSCs did not cause an increase in the expression of COX-1 and COX-2 proteins. However, when the combination was exposed to IL-1ß, there was an increase in the expression of COX-2. This study demonstrates the potential application of nopal scaffolds in tissue engineering and regenerative medicine or dentistry, owing to their structural characteristics, degradation properties, mechanical properties, ability to induce cell proliferation, and lack of enhancement of pro-inflammatory cytokines.

Effects of Nitrurized Titanium on Microhardness and Human Dental Pulp Stem Cell Adhesion and Differentiation.

To compare the Vickers microhardness, surface roughness, initial adhesion, and osteogenic differentiation on titanium (Ti) and nitrurized titanium (NTi) plates were treated by UV irradiation and chitosan. Each plate was subjected to Vickers hardness with a pressure of 2.9 N for 10 seconds and roughness evaluation by atomic force microscope (AFM) analysis. Three groups of each type of plates were tested: control (C), ultraviolet irradiation (UV), and chitosan (Q). The UV group was exposed to UV-irradiation for 20 min at 253.7 nm (52 µW/cm2). The Q group was coated with 1% chitosan, and the C group had no treatment. The osteoblasts (2 × 106 cells/mL) were inoculated in each group for 60 min and their viability was determined by the MTT bioassay. Osteogenic differentiation was performed over 4 weeks and determined by alizarin red staining. The mean was analyzed with the Shapiro-Wilks, Kruskall-Wallis, and Mann-Whitney U tests of normality (n = 9/gp). The NTi plates hardness (125.1 ± 4.01 HV) was higher (P = 0.026) than the Ti plates (121.3 ± 2.23 HV). The surface topography was: NTi (Ra = 0.098 µm) and Ti (Ra = 0.212 µm). The quantification of cell adhesion was: Ti + Q = 123 ± 4.9% (P < 0.05) < NTi + Q = 107 ± 3.3% < Ti = 100 ± 10.7% < NTi = 72 ± 6.8% < NTi + UV = 71 ± 4.4% < Ti + UV = 69 ± 3.5%, regardless the plates, the presence of chitosan induce a faster osteogenic differentiation. The Ti + Q plates tested the highest cell attachment and osteogenic adhesion suggesting their potential use of chitosan for cell-implant interaction.

Natural Bioactive Epigallocatechin-Gallate Promote Bond Strength and Differentiation of Odontoblast-like Cells.

The (-)-Epigallocatechin-gallate (EGCG) metabolite is a natural polyphenol derived from green tea and is associated with antioxidant, biocompatible, and anti-inflammatory effects. OBJECTIVE: To evaluate the effects of EGCG to promote the odontoblast-like cells differentiated from human dental pulp stem cells (hDPSCs); the antimicrobial effects on Escherichia coli, Streptococcus mutans, and Staphylococcus aureus; and improve the adhesion on enamel and dentin by shear bond strength (SBS) and the adhesive remnant index (ARI). MATERIAL AND METHODS: hDSPCs were isolated from pulp tissue and immunologically characterized. EEGC dose-response viability was calculated by MTT assay. Odontoblast-like cells were differentiated from hDPSCs and tested for mineral deposition activity by alizarin red, Von Kossa, and collagen/vimentin staining. Antimicrobial assays were performed in the microdilution test. Demineralization of enamel and dentin in teeth was performed, and the adhesion was conducted by incorporating EGCG in an adhesive system and testing with SBS-ARI. The data were analyzed with normalized Shapiro-Wilks test and ANOVA post hoc Tukey test. RESULTS: The hDPSCs were positive to CD105, CD90, and vimentin and negative to CD34. EGCG (3.12 µg/mL) accelerated the differentiation of odontoblast-like cells. Streptococcus mutans exhibited the highest susceptibility < Staphylococcus aureus < Escherichia coli. EGCG increased (p < 0.05) the dentin adhesion, and cohesive failure was the most frequent. CONCLUSION: (-)-Epigallocatechin-gallate is nontoxic, promotes differentiation into odontoblast-like cells, possesses an antibacterial effect, and increases dentin adhesion.

State-of-the-art: MXene structures in nano-oncology.

Cancer nanomedicine has been investigated widely and boomed in the last two decades, resulting in designing nanostructures with biofunctionalization, giving rise to an "All-in-One" multifunctional platform. The development of rational design technology with extended functionalities brought interdisciplinary researchers to work continuously, aiming to find a prevent or effectively treat the deadly disease of the century. Thus, it led to some Food and Drug Administration (FDA)-approving nano-based formulations for cancer treatment and opening a vast area of promising discoveries by exploiting different nanomaterials. Two-dimensional (2D) materials have recently gained tremendous interest among scientists because of their outstanding structural, optical, electronic, thermal, and mechanical characteristics. Among various 2D nanomaterials, MXenes are a widely studied nanosystem because of their close similarity to graphene analogs. So, it is synthesized using multiple approaches and exploits their inherited properties. But in most cases, surface functionalization techniques are carried out for targeting, site-specific drug clearance, renal clearance, and biocompatible with healthy cells. Thus, fabricating a multimodal agent for mono or combined therapies is also an image-guided diagnostic agent. This review will explain the recent and emerging advancements of MXenes-based composites as a multifunctional theragnostic agent and discuss the possibilities of transferring laboratory research to clinical translation.

Enhancement of fluoride release in glass ionomer cements modified with titanium dioxide nanoparticles.

BACKGROUND: Several efforts have been made to improve the glass ionomer cements (GICs) properties with nanotechnology. Fluoride release in once of most beneficial properties of GICs. The purpose of this study was to evaluate the fluoride release, recharge, and cytotoxicity in GICs reinforced with titanium dioxide nanoparticles (TiO2N). OBJECTIVE: Evaluate the fluoride release, recharge, and cytotoxicity in GICs reinforced with TiO2N. METHODS: Four GICs, FUJI IX EXTRA (G1c), KETAC MOLAR (G2c), IONOFILL MOLAR (G3c), and FUJI IX (G4c) were combined with TiO2N (G1e, G2e, G3e, and G4e) and divided into blocks of 5-mm width and 1-mm thickness 10 each. A total of 80 samples were arranged as follows: GICs alone as negative control (n = 40) and GICs + TiO2N as experimental groups (n = 40). The fluoride release was determined for periods of 1, 2, 6, 10, 31, 90, 180, 240, and 300 days. On days 30 and 179, samples were recharged by submerging in 1 mL of 20,000 ppm sodium fluoride gel. Cytotoxic activity was carried out with gingival fibroblasts, using 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide cell viability assay. RESULTS: The experimental groups obtained the highest and more constant fluoride released when compared to control groups. After the first recharge, experimental groups (G1e, G3e, and G4e) showed statistically significant results (P = .001, 0.010, and 0.001 respectively) enhancing their recharge ability regarding control groups. The second recharge showed better results in G1e concerning the rest of the groups. No cytotoxic activity was observed in all experimental groups, although significant differences were observed in G3e and G4e regarding control group. CONCLUSION: The incorporation of TiO2N enhance the fluoride release in glass ionomers with a noncytotoxic effect on human gingival fibroblasts.

Gel dressing based on type I collagen modified with oligourethane and silica for skin wound healing.

Cutaneous wound healing is a complex process that leads the skin reparation with the formation of scar tissue that typically lacks skin appendages. This fact drives us to find new strategies to improve regenerative healing of the skin. This study outlines, the contribution of colloidal silica particles and oligourethane crosslinking on the collagen material properties and the effect on skin wound healing in rats. We characterized the gel properties that are key forin-situgelation, which is accomplished by the latent reactivity of oligourethane bearing blocked isocyanate groups to crosslink collagen while entrapping silica particles. The swelling/degradation behavior and the elastic modulus of the composite gel were consistent with the modification of collagen type I with oligourethane and silica. On the other hand, these gels were characterized as scaffold for murine macrophages and human stem cells. The application of a composite gel dressing on cutaneous wounds showed a histological appearance of the recovered skin as intact skin; featured by the epidermis, hair follicles, sebaceous glands, subcutaneous adipose layer, and dermis. The results suggest that the collagen-based composite dressings are promising modulators in skin wound healing to achieve a regenerative skin closure with satisfactory functional and aesthetic scars.

Fracture Resistance of Endodontically Restored Teeth with Two System Root Post

ABSTRACT: The objective of this study was to determinate the fracture resistance of endodontically treated teeth and restored with two root post systems: i) resin post, ii) fiber post. A total of 60 teeth were freshly extracted, endodontic ally treated and randomly divided in two groups (n= 30/each group) for standardized restoration; Group 1 (Group R): Resin post and resin restoration, Group 2 (Group FP): Fiberglass post and resin restoration. Both groups' samples were mounted in a metallic base at 135º to allow them to be stabilized and held in the universal testing machine by applying a vertical force at cross speed of 1mm/min. Data were recorded in Newtons (N) Previous to test the fracture resistance; all samples were stored in distilled water at 37 ºC for 24 hours. Data were subject to the Saphiro-Wilk test for normality distribution and Student's t test. Significance was considered at 0.05 values. The values of fiber post group showed normal distribution compared to the resin group, demonstrating less variability among the values. The group FP displayed higher fracture resistance (299.77±100 N) than group R (205.57±86.40 N), with significant differences (p= 0.00002). The greatest fracture resistance was recorded for the group having fiber post reinforced and composite cores. It is suggested that fiberglass post restoration is the first option when endodontic treatment requires core restoration.

RESUMEN: El objetivo del estudio fue determinar la resistencia a la fractura de dientes tratados endodónticamente y restaurados con dos sistemas de endopostes radiculares: I) poste de resina, II) poste de fibra. Un total de 60 dientes recién extraídos fueron tratados endodónticamente y divididos al azar en dos grupos (n= 30/ cada grupo) para la restauración estandarizada; Grupo 1 (Grupo R): Pilares de resina y restauración, Grupo 2 (Grupo FP): Pilares de fibra de vidrio y restauración de resina. Las muestras de ambos grupos se montaron en una base metálica a 135º para permitir su estabilización y sujeción en la máquina universal de ensayos aplicando una fuerza vertical a velocidad transversal de 1 mm/min. Los datos se registraron en Newtons (N), para probar la resistencia a la fractura; todas las muestras se almacenaron en agua destilada a 37 ºC durante 24 horas. Los datos se sometieron a la prueba de normalidad de Saphiro-Wilk y la pruebas t de Student. La significancia se consideró con un valor de 0,05. Los valores del grupo de postes de fibra mostraron una distribución normal en comparación con el grupo de resinas, demostrando menor variabilidad entre los valores. El grupo FP mostró mayor resistencia a la fractura (299,77±100 N) que el grupo R (205,57±86,40 N) que el grupo con diferencias significativas (p= 0,00002). La mayor resistencia a la fractura se registró para el grupo que tenía núcleos compuestos y reforzados con postes de fibra. Se sugiere que la restauración posterior de fibra de vidrio es la primera opción cuando el tratamiento de endodoncia requiere una restauración del núcleo.

CRISPR/Cas gene-editing technology and its advances in dentistry.

A recent discovery of revolutionary Clustered regularly interspaced palindromic repeats (CRISPR) is a gene-editing tool that provides a type of adaptive immunity in prokaryotic organisms, which is currently used as a revolutionizing tool in biomedical research. It has a mechanism of correcting genome errors, turning on/off genes in cells and organisms. Most importantly playing a crucial function in bacterial defence by identifying and destroying Deoxyribonucleic acid (DNA) segments during bacteriophage invasions since the CRISPR-associated protein 9 (Cas9) enzyme recognizes and cleaves invasive DNA sequences complementary to CRISPR. Therefore, researchers employ this biological device to manipulate the genes to develop new therapies to combat systemic diseases. Currently, the most significant advance at the laboratory level is the generation of cell and animal models, functional genomic screens, live images of the cell genome, and defective DNA repairs to find the cure for genetic disorders. Even though this technology has enormous biomedical applications in various sectors, this review will summarize CRISPR/Cas emphasizing both the therapeutic and diagnostic mechanisms developed in the field of dentistry and the promising attempts to transfer this technology to clinical application. Finally, future developments are also described, which proposes to use CRISPR/Cas systems for prospective clinical dentistry applications.

[Cancer stem cells in oral squamous cell carcinoma. Literature review]. / Células troncales cancerígenas en carcinoma oral de células escamosas. Revisión de la literatura.

Objective: To perform a literature review on oral squamous cell carcinoma, the presence of cancer stem cells; their association with the course of the disease and therapeutic applications. Methods: : A search was performed in the PubMed database by entering the following algorithm: ((((neoplastic stem cells [MeSH Terms ]) OR (Cancer stem cells [Text Word ])) AND (Squamous Cell Carcinoma of Head and Neck [MeSH Terms])) AND (Oral squamous cell carcinoma [Text Word ]), to find articles in english published between 2012 and 2022. The PRISMA diagram was used to identify and select the articles. Results: A result of 49 articles was obtained; of which 27 were chosen according to the title and abstract in their association with the topic. In addition, 8 additional articles suggested by their relationship with the information previously searched were included. In total, 35 articles were evaluated. There has been found that tumoral cells in squamous oral carcinoma are heterogeneous since they include cancer stem cells wich possess characteristics of stem and neoplasic cells; which possess characteristics of stem cells as well as neoplastic cells; they have been associated with disease progression, recurrence, and metastasis and have been considered to be a key mechanism of therapy failure. Conclusions: The expression of stem cell markers in oral squamous cell carcinomas has been demonstrated and has contributed to their identification in oral squamous cell carcinomas and has been implicated in the behavior of cancer cells. New therapeutic measures aimed at eliminating cancer stem cells have been proposed and developed.

2D Nanosheets-A New Class of Therapeutic Formulations against Cancer.

Researchers in cancer nanomedicine are exploring a revolutionary multifaceted carrier for treatment and diagnosis, resulting in the proposal of various drug cargos or "magic bullets" in this past decade. Even though different nano-based complexes are registered for clinical trials, very few products enter the final stages each year because of various issues. This prevents the formulations from entering the market and being accessible to patients. In the search for novel materials, the exploitation of 2D nanosheets, including but not limited to the highly acclaimed graphene, has created extensive interest for biomedical applications. A unique set of properties often characterize 2D materials, including semiconductivity, high surface area, and their chemical nature, which allow simple decoration and functionalization procedures, structures with high stability and targeting properties, vectors for controlled and sustained release of drugs, and materials for thermal-based therapies. This review discusses the challenges and opportunities of recently discovered 2D nanosheets for cancer therapeutics, with special attention paid to the most promising design technologies and their potential for clinical translation in the future.

Cytotoxic and anti-inflammatory effects of chitosan and hemostatic gelatin in oral cell culture.

Chitosan is a biopolymer with bactericidal/bacteriostatic effect, biocompatible and biodegradable. It has been used in tissue engineering to replace tissues partially or completely by releasing bioactive materials or influencing cell growth, usually in regenerative medicine and dentistry. The aim of this study was to evaluate the cytotoxic and anti-inflammatory effect of chitosan alone or with hemostatic gelatin (Spongostand®) in cultures of human pulp cells (HPC), human gingival fibroblasts (HGF) and mouse pre-osteoblasts (MC3T3-E1, ATCC). HPC and HGF were isolated from patients. Cells were subcultured in DMEM. Chitosan was inoculated at different concentrations (0-0.5%) and hemostatic gelatins impregnated with chitosan (0.19%) were placed directly in the presence of cells and incubated for 24 hours. Cell viability was determined by MTT method and mean cytotoxic concentration (CC50) was calculated from the dose-response curve. Anti-inflammatory effect was calculated from the in vitro gingivitis model induced with interleukin 1beta (IL-1ß) in HGF and protein detection. The data were subjected to Shapiro-Wilk, Kruskal-Wallis and Mann-Whitney tests. Experiments were performed in triplicate of three independent assays. Cell viability of HPC, HGF and MC3T3-E1 in contact with chitosan decreased significantly (p<0.05). The HPC were the most sensitive (CC50= 0.18%), followed by HGF (CC50= 0.18%) and MC3T3-E1 (CC50= 0.19%). The cytotoxicity of gelatins impregnated with chitosan decreased cell viability of HGF and HPC by 11% and 5%, respectively. The proinflammatory effect was reduced significantly in the gingivitis model. To conclude, chitosan induces moderate cytotoxic effects alone or with hemostatic gelatin at 0.19%, in dose-dependent manner, with anti-inflammatory effects on human gingival fibroblasts. The use of chitosan as a biomaterial can be an excellent choice for use in regenerative dentistry.

El quitosano es un biopolímero con efecto bactericida/bacteriostático, biocompatible y biodegradable. Se ha utilizado en ingeniería de tejidos con el fin de reemplazar parcial o completamente los tejidos como material bioactivo o influyendo en el crecimiento celular, comúnmente, para medicina y odontología regenerativa. Evaluar el efecto citotóxico y antiinflamatorio del quitosano solo o con gelatina hemostática (Spongostand®) en cultivos con células pulpares humanas (HPC), fibroblastos gingivales humanos (HGF) y preosteoblastos de ratón (MC3T3-E1, ATCC). HPC, HGF se aislaron de pacientes. Las células se subcultivaron en DMEM. Se inoculó quitosano a diferentes concentraciones (0-0,5%) y se colocaron gelatinas hemostáticas impregnadas con quitosano (0,19%) directamente en presencia de células y se incubaron durante 24 horas. La viabilidad celular se determinó mediante el método MTT y se calculó la concentración citotóxica media (CC50) a partir de la curva dosis-respuesta. El efecto antiinflamatorio se calculó a partir del modelo de gingivitis in vitro inducido con interleucina 1ß (IL-1ß) en HGF. Los datos se sometieron a las pruebas de Shapiro-Wilk, Kruskal-Wallis y Mann-Whitney. Los experimentos se realizaron por triplicado de tres ensayos independientes. La viabilidad celular de HPC, HGF y MC3T3-E1 en contacto con el quitosano disminuyó significativamente la viabilidad celular (p<0.05). Las HPC fueron las más sensibles (CC50= 0,18%) seguido de HGF (CC50= 0,18%) y MC3T3-E1 (CC50= 0,19%). Las gelatinas impregnadas con quitosano mostraron una disminución en la viabilidad celular para HGF, HPC de 11% y 5% respectivamente y se redujo significativamente el efecto pro-inflamatorio en el modelo de gingivitis humano. El quitosano induce efectos citotóxicos moderados solo o con gelatina hemostática a 0,19% de forma dosis-dependiente con efectos antiinflamatorios en fibroblastos gingivales humanos. El uso de quitosano como biomaterial puede ser una excelente opción para su uso en odontología regenerativa.

Cytotoxic and Pro-Inflammatory Effects of Miniscrews Subject to Corrosion in Oral Cell Cultures.

Cytotoxic and pro-inflammatory effects of mini-screws subject to corrosion in oral cells culture. To analysis the products of corrosion of three different commercial orthodontic mini-screws and evaluate the cytotoxicity and pro-inflammatory effects in culture with human gingival fibroblast cells (HGFs) and human osteoblast-like bone surface cells (HBCs). An experimental in vitro study was carried out with 3 different type of mini-screws: Vector-Tas®, Forestadent ORTHOEasy®, Bio-Ray® (n = 30/gp). The samples were subjected to accelerated corrosion for 24, 48, 72 and 96 hours, which were observed with a stereomicroscope and scanning electron microscope. The corrosion products were analyzed by inductively coupled plasma with mass spectrometry. The direct and indirect cytotoxicity was tested in culture with HGFs and HBCs, cell viability was determined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. The pro-inflammatory effect was determined by the expression of prostaglandin E2 (PGE2) with the ELISA test. The data were subjected to Shapiro-Wilks normality tests, paired t-tests and Tukey's post hoc ANOVA. The mini-screw topography showed significant morphological changes after corrosion. The main ions after corrosion were Al, Ti, and Fe. Corrosion products by direct and indirect contact with cells slightly reduced (P < 0.05) cell viability, considered non-cytotoxic. The expression of PGE2 was not increased by the presence of the corrosion products even in a previous pro-inflammatory state. The corrosion products were not cytotoxic and did not induce a pro-inflammatory state in culture with HGFs and HBCs.

Silver Nanoparticles from Annona muricata Peel and Leaf Extracts as a Potential Potent, Biocompatible and Low Cost Antitumor Tool.

Cancer is one of the most prevalent diseases in the world and requires new therapies for its treatment. In this context, the biosynthesis of silver nanoparticles (AgNPs) has been developed to treat different types of tumors. The Annona muricata plant is known for having anticancer activity. Its main compounds present in the leaves, stems and skin, allowing for its use as reducing agents. In this manuscript, AgNPs with leaf extract (AgNPs-LE) and fruit peel extract (AgNPs-PE) of A. muricata were biosynthesized obtaining an average nanoparticle diameter sizes smaller than 50 nm, being 19.63 ± 3.7 nm and 16.56 ± 4.1 nm, and with a surface plasmonic resonance (SPR) at 447 and 448 nm, respectively. The lactone functional group present in the LE and PE extracts was identified by the FTIR technique. The behavior and antiproliferation activity of AgNPs-LE and AgNPs-PE were evaluated in breast, colon and melanoma cancer cell lines. Our results showed that Annona muricata fruit peel, which is a waste product, has an antitumor effect more potent than leaf extract. This difference is maintained with AgNPs where the destruction of cancer cells was, for the first time, achieved using concentrations that do not exceed 3 µg/mL with a better therapeutic index in the different tumor strains. In conclusion, we present a low-cost one-step experimental setup to generate AgNPs-PE whose in-vitro biocompatibility and powerful therapeutic effect make it a very attractive tool worth exploiting.

Cytotoxic and anti-inflammatory effects of chitosan and hemostatic gelatin in oral cell culture / Efectos citotóxicos y antiinflamatorios del quitosano y la gelatina hemostática en cultivo celular oral

ABSTRACT Chitosan is a biopolymer with bactericidal/bacteriostatic effect, biocompatible and biodegradable. It has been used in tissue engineering to replace tissues partially or completely by releasing bioactive materials or influencing cell growth, usually in regenerative medicine and dentistry. The aim of this study was to evaluate the cytotoxic and anti-inflammatory effect of chitosan alone or with hemostatic gelatin (Spongostand®) in cultures of human pulp cells (HPC), human gingival fibroblasts (HGF) and mouse pre-osteoblasts (MC3T3-E1, ATCC). HPC and HGF were isolated from patients. Cells were subcultured in DMEM. Chitosan was inoculated at different concentrations (0-0.5%) and hemostatic gelatins impregnated with chitosan (0.19%) were placed directly in the presence of cells and incubated for 24 hours. Cell viability was determined by MTT method and mean cytotoxic concentration (CC50) was calculated from the dose-response curve. Anti-inflammatory effect was calculated from the in vitro gingivitis model induced with interleukin 1beta (IL-1β) in HGF and protein detection. The data were subjected to Shapiro-Wilk, Kruskal-Wallis and Mann-Whitney tests. Experiments were performed in triplicate of three independent assays. Cell viability of HPC, HGF and MC3T3-E1 in contact with chitosan decreased significantly (p<0.05). The HPC were the most sensitive (CC50= 0.18%), followed by HGF (CC50= 0.18%) and MC3T3-E1 (CC50= 0.19%). The cytotoxicity of gelatins impregnated with chitosan decreased cell viability of HGF and HPC by 11% and 5%, respectively. The proinflammatory effect was reduced significantly in the gingivitis model. To conclude, chitosan induces moderate cytotoxic effects alone or with hemostatic gelatin at 0.19%, in dose-dependent manner, with anti-inflammatory effects on human gingival fibroblasts. The use of chitosan as a biomaterial can be an excellent choice for use in regenerative dentistry.

RESUMEN El quitosano es un biopolímero con efecto bactericida/bacteriostático, biocompatible y biodegradable. Se ha utilizado en ingeniería de tejidos con el fin de reemplazar parcial o completamente los tejidos como material bioactivo o influyendo en el crecimiento celular, comúnmente, para medicina y odontología regenerativa. Evaluar el efecto citotóxico y antiinflamatorio del quitosano solo o con gelatina hemostática (Spongostand®) en cultivos con células pulpares humanas (HPC), fibroblastos gingivales humanos (HGF) y preosteoblastos de ratón (MC3T3-E1, ATCC). HPC, HGF se aislaron de pacientes. Las células se subcultivaron en DMEM. Se inoculó quitosano a diferentes concentraciones (0-0,5%) y se colocaron gelatinas hemostáticas impregnadas con quitosano (0,19%) directamente en presencia de células y se incubaron durante 24 horas. La viabilidad celular se determinó mediante el método MTT y se calculó la concentración citotóxica media (CC50) a partir de la curva dosis-respuesta. El efecto antiinflamatorio se calculó a partir del modelo de gingivitis in vitro inducido con interleucina 1β (IL-1β) en HGF. Los datos se sometieron a las pruebas de Shapiro-Wilk, Kruskal-Wallis y Mann-Whitney. Los experimentos se realizaron por triplicado de tres ensayos independientes. La viabilidad celular de HPC, HGF y MC3T3-E1 en contacto con el quitosano disminuyó significativamente la viabilidad celular (p <0.05). Las HPC fueron las más sensibles (CC50= 0,18%) seguido de HGF (CC50= 0,18%) y MC3T3-E1 (CC50= 0,19%). Las gelatinas impregnadas con quitosano mostraron una disminución en la viabilidad celular para HGF, HPC de 11% y 5% respectivamente y se redujo significativamente el efecto pro-inflamatorio en el modelo de gingivitis humano. El quitosano induce efectos citotóxicos moderados solo o con gelatina hemostática a 0,19% de forma dosis-dependiente con efectos antiinflamatorios en fibroblastos gingivales humanos. El uso de quitosano como biomaterial puede ser una excelente opción para su uso en odontología regenerativa.

Biological and physico-mechanical properties of poly (methyl methacrylate) enriched with graphene oxide as a potential biomaterial / Propiedades físicas-mecánicas-biológicas del poli (metilmetacrilato) enriquecido con óxido de grafeno como potencial biomaterial

Objective: To determine the cytotoxicity and effects of graphene oxide (GO) on cellular proliferation of gingival-fibroblasts, pulp-dental cells and human osteoblasts in culture, and to determine the physical, mechanical and biological properties of poly (methyl methacrylate) (PMMA) enriched with GO. Material and Methods: The GO was characterized with SEM. Cytotoxicity and cell proliferation were determined by the MTT bioassay. The physical mechanical tests (flexural strength and elastic modulus) were carried out with a universal testing machine. Sorption and solubility were determined by weighing before and after drying and immersion in water. Porosity was evaluated by visual inspection. Data were analyzed with Student's t-test and Tukey's posthoc ANOVA. Results: The GO has a heterogeneous morphology and a particle size of 66.67±64.76 µm. GO has a slight to no-cytotoxicity (>50-75% viability) at 1-30 days, and at 24 hours incubation of PMMA with GO significantly stimulates osteoblasts (45±8%, p<0.01). The physical and mechanical properties of PMMA with GO increase considerably without altering sorption, solubility and porosity. Conclusion: GO alone or with PMMA has an acceptable biocompatibility, could contribute to cell proliferation, cell regeneration and improve the physical mechanical properties of PMMA.

Objective: To determine the cytotoxicity and effects of graphene oxide (GO) on cellular proliferation of gingival-fibroblasts, pulpdental cells and human osteoblasts in culture, and to determine the physical, mechanical and biological properties of poly (methyl methacrylate) (PMMA) enriched with GO. Material and Methods: T he G O w as c haracterized with SEM. Cytotoxicity and cell proliferation were determined by the MTT bioassay. The physical-mechanical tests (flexural strength and elastic modulus) were carried out with a universal testing machine. Sorption and solubility were determined by weighing before and after drying and immersion in water. Porosity was evaluated by visual inspection. Data were analyzed with Student's t-test and Tukey's post-hoc ANOVA. Results: The GO has a heterogeneous morphology and a particle size of 66.67±64.76 ?m. GO has a slight to no-cytotoxicity (>50-75% viability) at 1-30 days, and at 24 hours incubation of PMMA with GO significantly stimulates osteoblasts (45±8%, p<0.01). The physical and mechanical properties of PMMA with GO increase considerably without altering sorption, solubility and porosity. Conclusion: GO alone or with PMMA has an acceptable biocompatibility, could contribute to cell proliferation, cell regeneration and improve the physical-mechanical properties of PMMA.

Antifungal biomaterial for reducing infections caused by Candida albicans in edentulous patients.

INTRODUCTION: Polymethylmethacrylate (PMMA) acrylic resins are used to make dentures for edentulous patients. OBJECTIVE: To find out the prevalence of Candida species in patients with and without removable prostheses from a dental clinic in León, Guanajuato, as well as to assess the antifungal effect and biological behavior of an experimental PMMA with silver nanoparticles for its possible application in prostheses. METHOD: To identify Candida species, smear samples were obtained from the palatal mucosa of 140 patients aged ≥ 60 years. The experimental PMMA with silver nnoparticles was placed in Candida albicans cultures, which were stained with the Live/Dead® kit for analysis under confocal microscopy; subsequently, it was implanted in Wistar rats in order to know its behavior in the surrounding tissues. RESULTS: Candida albicans was the most prevalent species in the evaluated patients, followed by Candida tropicalis and Candida krusei. The acrylic resin with silver nanoparticles significantly decreased the presence of Candida albicans. In the animal model, a discrete and controlled inflammatory reaction was found, which indicated biocompatibility of the acrylic resin that was used. CONCLUSIONS: It is possible for the nanostructured material with antifungal effect to be used in order to promote the reduction of oral Candida infections in edentulous patients.

INTRODUCCIÓN: Las resinas acrílicas de polimetilmetacrilato (PMMA) son utilizadas para elaborar dentaduras para pacientes edéntulos. OBJETIVO: Conocer la prevalencia de las especies de Candida en pacientes con y sin prótesis removibles de una clínica de odontología en León, Guanajuato; así como valorar el efecto antifúngico y el comportamiento biológico de un PMMA experimental con nanopartículas de plata para su posible aplicación en prótesis. MÉTODO: Para identificar las especies de Candida se obtuvieron muestras para frotis de la mucosa palatina de 140 pacientes con edad ≥ 60 años. El PMMA experimental con nanopartículas de plata fue colocado en cultivos de Candida albicans, los cuales fueron teñidos con el kit Live/Dead® para su análisis bajo microscopia confocal; posteriormente, se implantó en ratas Wistar para conocer su comportamiento en los tejidos circundantes. RESULTADOS: Candida albicans fue la especie más prevalente en los pacientes valorados, seguida de Candida tropicalis y Candida krusei. La resina acrílica con nanopartículas de plata disminuyó significativamente la presencia de Candida albicans. En el modelo animal se encontró reacción inflamatoria discreta y controlada, lo cual indicó la biocompatibilidad de la resina acrílica utilizada. CONCLUSIONES: Es posible utilizar el material nanoestructurado con efecto antifúngico para promover la reducción de infecciones orales por Candida en pacientes edéntulos.