Laser Irradiation Group Research Articles

Photobiomodulation Improves Histological Parameters of Testis and Spermatogenesis in Adult Mice Exposed to Scrotal Hyperthermia in the Prepubertal Phase.

Introduction: Heat stress is one of the environmental causes of damage to the testis, whose effects are less known before puberty. The aim of the present study was to investigate the impact of photobiomodulation (PBM) on the testis of prepubertal mice subjected to hyperthermia. Methods: Twenty-four three-week-old prepubertal male mice were allocated to the following groups: I) control, II) scrotal hyperthermia (Hyp), and III) Hyp+PBM (n=8/each group). In order to induce hyperthermia, the scrotum was placed in water at 43 °C for 20 minutes every other day for a total duration of 10 days. In the Hyp+PBM group, after hyperthermia induction, the testis of the mice was subjected to laser irradiation at a wavelength of 890 nm (0.03 J/cm2 for 30 seconds) for 35 days. After the mice were sacrificed, the testis and epididymis were removed for testing. Results: Compared with those of the Hyp group, the sperm parameters of the laser irradiation group improved notably. In addition, histological examinations revealed that the final number of testis cells and the volume of tissue in the Hyp+PBM group were dramatically greater than those in the Hyp group. The analysis of molecular data revealed an increase in the expression of mitotic genes and testosterone levels and a decrease in the formation of reactive oxygen species (ROS) and the expression of the apoptotic gene in the testis subjected to PBM. Conclusion: Based on the present findings, laser therapy can reduce complications caused by scrotal hyperthermia during prepuberty and ameliorate spermatogenesis during puberty.

In Vitro Effect of Photodynamic Therapy With Curcumin in Combination With Photobiomodulation Therapy by 660 nm on the Viability of Human Gingival Fibroblasts.

Introduction: This study aimed to assess the effect of repeated irradiations of 660 nm photobiomodulation therapy (PBMT) after photodynamic therapy (PDT) with curcumin on the viability of human gingival fibroblasts (HGFs). Methods: In this in vitro, experimental study, HGFs were cultured and assigned to five groups: One control group with no intervention and four experimental groups of PDT with curcumin, PBMT (660 nm laser irradiation) immediately after PDT, PBMT immediately and 24 hours after PDT and PBMT immediately and 24 hours and 48 hours after PDT. Cell viability was assessed after 1, 4, and 7 days using the methyl thiazolyl tetrazolium (MTT) assay. Data were analyzed by one-way ANOVA. Results: On day 1, the control group had no significant difference with one-time (P=1.00), two-time (P=1.00), and three-time (P=0.88) laser irradiation groups. On day 4, the difference between the control and one-time (P<0.001), two-time (P<0.001) and three-time (P=0.02) laser irradiation groups was statistically significant, suggesting more cell viability in test groups. On day 7, the three-time laser irradiation group showed significant cell viability compared to the other two test groups but not with the control group (P=0.98). Conclusion: PBMT with 660 nm laser irradiation after PDT with curcumin would increase the viability of HGFs by increasing the frequency of irradiation.

High-frequency low-intensity semiconductor laser irradiation enhances osteogenic differentiation of human cementoblast lineage cells

PurposeLaser irradiation activates a range of cellular processes in the periodontal components and promotes tissue repair. However, its effect on osteogenic differentiation of human cementoblast lineage cells remains unclear. This study aimed to examine the effects of high-frequency semiconductor laser irradiation on the osteogenic differentiation of human cementoblast lineage (HCEM) cells.MethodsHCEM cells were cultured to reach 80% confluence and irradiated with a gallium-aluminum-arsenide (Ga-Al-As) semiconductor laser with a pulse width of 200 ns and wavelength of 910 at a dose of 0–2.0 J/cm2. The outcomes were assessed by analyzing the mRNA levels of alkaline phosphatase (ALP), runt-related transcription factor 2 (RUNX2), and type I collagen (COLL1) using real-time polymerase chain reaction (PCR) analysis 24 h after laser irradiation. Cell mineralization was evaluated using ALP activity, calcium deposition, and Alizarin Red staining.ResultsThe laser-irradiated HCEM cells showed significantly enhanced gene expression levels of ALP, RUNX2, and COLL1 as well as ALP activity and calcium concentration in the culture medium compared with the non-irradiated cells. In addition, enhanced calcification deposits were confirmed in the laser-irradiated group compared with the non-irradiated group at 21 and 28 days after the induction of osteogenic differentiation.ConclusionHigh-frequency semiconductor laser irradiation enhances the osteogenic differentiation potential of cultured HCEM cells, underscoring its potential utility for periodontal tissue regeneration.

Dentin Collagen versus Er:YAG Laser as Surface Biomodifiers for Intact Root Slices Simulating Delayed Replanted Roots.

Objective: To evaluate effects of dentin collagen versus Er:YAG laser application through enhancing human periodontal ligament fibroblast (PDLF) cells to attach to intact root surfaces imitating delayed replanted roots. Background Data: Accidental traumatic injuries with teeth avulsion are managed by replantation. Root resorption, poor conditioning, and non-viable fibroblasts are factors responsible for failure. Methods: Thirty six human healthy single-rooted premolars were collected. Six teeth were used for PDLF, six teeth used for dentin collagen, whereas the remaining 24 teeth (48 root slices) were used for PDLF cell density and morphology. Each root was soaked in 5.25% NaOCl. Three groups (n = 16 slices/each) were planned as follows: I: Control (untreated); II: dentin collagen application; III: Er:YAG laser irradiation (4 mm distance, 40 mJ/pulse, under coolant). Following incubation, cell density and morphology of PDLF were investigated under SEM. Statistical analysis was performed using analysis of variance with Scheffé's test, and p < 0.05 was considered significant. Results: All groups showed increased cultured PDLF following incubation. Regarding cell density, attached PDLFs were significantly lower in untreated controls (36.5 ± 6.36) (p < 0.00001 i.e., <0.05) in negative empty and/or light cellular areas, compared with dentin collagen (65 ± 6) and laser-irradiated (66.75 ± 5.77) groups that did not show significant differences (p = 0.940 i.e., >0.05) and showed intermediate and/or heavy cellular areas. Regarding cell morphology, controls showed round and/or oval appearance with less lamellipodia, whereas dentin collagen and laser groups showed flat morphology with cytoplasmic processes. Conclusions: Both dentin collagen and Er:YAG laser showed comparable effectiveness as biomodification tools with good biocompatibility for human PDLF cell attachment on intact root slices imitating delayed replantation. Dentin collagen as a natural bioactive material is considered an alternative to Er:YAG laser to enhance the regenerative effects.

Effect of low-level laser therapy on proliferation and cytotoxicity of mouse fibroblasts and human fibroblasts: An in vitro study

Abstract: Background: Diode laser is known for its biostimulatory effects on various cell populations such as osteoblasts and fibroblasts. The usage of low-level laser therapy for photobiomodulation depends on its type, emission wavelength, and energy selected. Previously performed in vitro studies have determined its effect on cell proliferation and cytotoxicity; however, the results were inconsistent. Objectives: The objectives of this study were to evaluate and compare diode laser effect on mouse embryonic fibroblasts (MEFs) and human gingival fibroblasts (HGFs) for proliferation and cytotoxicity. Materials and Methods: 32 samples, 16 wells of MEF cells (Group I) and HGF cells (Group II) each with 8 subgroups containing control (no laser irradiation) and experimental (laser irradiated) groups were cultured after being seeded at 4000 cells/ well with 4cm inter-well distance. Experimental group cell cultures were irradiated with a single dose of 810 nm diode laser (energy 1J/cm2, 12.5 mW, 80 s/well) using continuous wave mode after 1 day of incubation. Spectrophotometric analysis was done after 24 h of laser irradiation for cell proliferation and cell cytotoxicity on the 2nd, 3rd, and 7th days on all groups. Results: Human and mouse fibroblast groups showed positive results when irradiated with an 810 nm laser. A hundred percent proliferation was seen for MEF in 7 days and HGF in 2 days. Two percent cytotoxicity was seen on the 2nd and 3rd day in MEF. Increased cell proliferation and minimal cytotoxic effects were seen with diode laser usage. Conclusion: Low-level laser irradiation indicates an increase in cell proliferation with less cytotoxicity on mouse and human fibroblasts.

The effect of pulsed Er,Cr:YSGG laser scanning on the adhesion strength of lithium disilicate to tooth dentin

This study examined how Er,Cr:YSGG laser surface conditioning affected the adhesion of lithium disilicate ceramic to the dentin tooth structure. Forty samples were divided into four groups (n=10). The first group was untreated, whereas the second was etched with hydrofluoric acid. The third group was treated for 2 minutes with a 7 W, 25 Hz Er,Cr:YSGG laser. The fourth group received the same Er,Cr:YSGG laser treatment at 5 W. The untreated group had the lowest shear bond scores. Laser-irradiated Group 3 at 7 W had a higher maximum shear bond strength than the hydrofluoric acid-etched group. The laser-irradiated groups also had a more uniform, non-invasive surface roughness pattern. The samples were tested by atomic force microscopy, scanning electron microscopy, and a universal shear bond testing machine. Surface treatment with the Er,Cr:YSSG laser at 7 W improves lithium disilicate ceramic adhesion to dentin. The laser outperforms hydrofluoric acid as the gold standard.

Remineralization effect of Er;Cr:YSGG laser irradiation with or without acidulated phosphate fluoride application on deciduous teeth enamel surface with induced white spot lesion. An in vitro study.

This study aims to assess the efficacy of Er; Cr: YSGG laser operating under sub-ablative settings for the remineralization of artificially induced white spot lesions on the enamel of primary teeth, both as a standalone treatment and in conjunction with 1.23% acidulated phosphate fluoride (APF) gel. Eighty primary posterior teeth were used to induce white spot lesions and were randomly divided into eight groups. The groups consisted of a negative control group (G1), a 0.75W laser irradiation group (G2), a 0.5W laser irradiation group (G3), a 0.25W laser irradiation group (G4), a positive control group with APF gel application (G5), and three groups that received laser irradiation of 0.75W, 0.5W, and 0.25W followed by APF gel application (G6, G7, and G8) respectively. Surface microhardness, SEM, and X-RD were used to evaluate the remineralization effect. There was a notable enhancement in surface microhardness post-treatment with the laser, APF gel, and their combination compared to the negative control group. The most pronounced increase in surface microhardness was observed in the combination treatment groups (G6, G7, and G8). SEM analysis showed increased surface roughness in groups treated with 0.75W and 0.5W laser power. X-RD assessments indicated an augmentation in crystal intensity within groups G6 and G8. The combined application of Er; Cr: YSGG laser under sub-ablative parameters and APF gel demonstrated a superior potential for remineralizing primary teeth enamel affected by white spot lesions. Key words:Er;Cr:YSGG laser. Sub-ablative irradiation. Remineralization. White spot lesion. APF gel. SEM. X-RD.

Construction of methylene blue embedded core–shell-satellite structured Au@Ag nanorods@SiO2@Au nanocomposites for synergistic therapy of cancer

Integration of multimodal therapies into one nanoplatform holds great promise to overcome the drawbacks of conventional single-modal therapy. Herein, we designed and constructed an ultrafine gold nanoparticle (Au NPs) decorated and methylene blue (MB) embedded core–shell-satellites structured Au@Ag nanorods@SiO2 nanocomposites (CSSNs) using a wet-chemical method. It can be found that excellent photothermal conversion performance and outstanding reactive oxygen species (ROS) production capacity were integrated on this one nonocomposites. In vitro experiments, all cancer cells were killed in nanocomposites with two laser irradiation group, which is better than that of nanocomposites without laser irradiation (12 % cancer cells were killed) and nanocomposites with one laser irradiation (660 nm laser, 84 % cancer cells were killed or 808 nm laser, 95 % cancer cells were killed). It is obviously that the synergistic effect was achieved between chemodynamic therapy (CDT), photodynamic therapy (PDT) and photothermal therapy (PTT). The vivo results further confirmed that the as-prepared nanocomposites can suppress the tumor growth without obvious systemic toxicity. This work will pave a new avenue for the construction of multifunctional nanocomposites and their multimodal therapy application for cancers.

Effects of low level laser on periodontal tissue remodeling in hPDLCs under tensile stress

This study aimed to investigate the effect of Low-Level Laser Therapy (LLLT) on human Periodontal Ligament Cells (hPDLCs) under tension stress. Primary hPDLCs were obtained using the tissue culture method, and P3 cells were utilized for the subsequent experiments. The study comprised four groups: a blank control group (Group B), a laser irradiation group (Group L), a tension stress group (Group T), and a laser + tension stress group (Group LT). Mechanical loading was applied using an in-vitro cell stress loading device at a frequency of 0.5 Hz and deformation of 2% for two hours per day for two days. Laser irradiation at 808 nm GaAlAs laser was administered 1 h after force loading. Cell samples were collected after the experiment. Bone and fiber remodeling factors were analyzed using PCR and Western blot. Flow cytometry was employed to assess the cell cycle, while ROS and Ca2+ levels were measured using a multifunctional enzyme labeling instrument. The results revealed that laser intervention under tension stress inhibited the expression of osteogenic differentiation factors, promoted the expression of osteoclast differentiation factors, and significantly increased the production of collagen factors, MMPs, and TIMPs. The LT group exhibited the most active cell cycle (P < 0.05). LLLT not only enhanced Ca2+ expression in hPDLCs under tension stress, but also stimulated the production of ROS. Overall, our findings demonstrate that LLLT effectively accelerated the proliferation of hPDLCs and the remodeling of periodontal tissue, possibly through the regulation of ROS and Ca2+ levels in hPDLCs.

Effect of Dentin and Zirconia Surface Treatments with Laser Irradiation Versus Sandblasting on the Bonding Ability of Zirconia.

Objective: This study aimed to investigate the effects of laser irradiation applied to zirconia and tooth surfaces on shear bond strength (SBS) compared with acid etching and sandblasting. Background: The effect of laser irradiation on the bond strength between zirconia and adhesives is a controversial issue for dentin surface treatments. In addition, the effects of different combinations of surface treatments to increase adhesion on both the zirconia and dentin surfaces remain unclear. Materials and methods: A total of 90 tooth samples were assigned into groups according to various pretreatments: control group was left untreated, acid etching, and Erbium, Chromium:Yttrium Scandium Gallium Garnet (Er,Cr:YSGG) laser irradiation group (15 Hz, 2 W). In addition, the zirconia specimens were separated into three groups (n = 10) according to the different surface treatments performed: sandblasting (120 μm Al2O3), Er,Cr:YSGG laser (15 Hz, 2 W), and as untreated surface. The zirconia samples were cemented to the dentin surface using dual-cure resin cement and subjected to an SBS test at a speed of 0.5 mm/min under a universal testing machine until fractures occurred in the bonding surface. Results: The highest SBS values were observed in Group tooth acid (TA)-zirconia Er,Cr:YSGG laser (ZL), followed by Group tooth Er,Cr:YSGG laser (TL)-zirconia sandblasting (ZS) and Group TA-zirconia control (ZC). The lowest SBS values were found in Group TA-ZS. Significant intergroup difference was noted between Group TA-ZL, Group tooth control (TC)-ZC, Group TL-ZS, and Group TC-ZC. However, no significant difference was noted between Group TA-ZL, Group TL-ZS, and Group TA-ZC. Conclusions: Acid etching and laser treatments applied to the dentin and zirconia surfaces were found to be effective techniques for improving the zirconia-dentin bond, respectively. Clinical Trial Registration number: 33216249-604.01.02-E.24308.

He-Ne laser irradiation in brinjal leads to metabolic rewiring and accumulation of bioactive components in fruits

Seed germination, seedling growth and healthy, virtue-based, uniform crop establishment are essential for considerable agricultural productivity. Physical and chemical techniques are widely utilized to promote and speed up seed germination. Due to their low cost, lack of side effects, environmental friendliness, non-destructive and low-power irradiation techniques such as laser, magnetic energy, and ultrasound are utilized successfully in various crops. The most well-known and well-studied laser in the agriculture sector is the Helium-Neon laser. The current study aimed to examine potential interactions between plants and laser rays and the possible use of the He-Ne laser to alter and enhance fruit metabolites. Fruits from field-grown brinjal (Solanum melongena L.) plants were collected at various developmental stages, such as 15, 30, 45, and 60 days post-anthesis (DPA), from the un-irradiated control and laser-irradiated plants for fruit metabolite profiling. Principal component analysis (PCA) and orthogonal partial least squares-discriminant analysis (OPLS-DA) indicated that the 15 DPA groups showed the highest variation compared to the other developmental stages. The observed metabolites were primarily divided into primary and secondary metabolites and are related to amino acids and derivatives, alkaloids and glycoalkaloids, fatty acids, organic acids, sugars, sugar alcohol, and terpenoids. Furthermore, the secondary metabolites were identified and classified into pigments, alkaloids, terpenoids, flavonoids, and glycoalkaloids. In the fruit tissues of the laser-irradiated groups, it was observed that the shikimate-derived phenolic pathway was not altered. On the other hand, the mevalonate route (MVP) and methylerythritol 4-phosphate (MEP) pathways were changed in the fruit tissues from the laser irradiation groups, according to the characterization of sterols, terpenoids, and alkaloids. Based on our previous reports and the current analysis, the biostimulatory role of the He-Ne laser was revealed with significant alterations in the abundance of bioactive molecules and their associated pathways in the developmental stages of brinjal fruits.

Effect of an low-energy Nd: YAG laser on periodontal ligament stem cell homing through the SDF-1/CXCR4 signaling pathway

BackgroundThe key to the success of endogenous regeneration is to improve the homing rate of stem cells, and low-energy laser is an effective auxiliary means to promote cell migration and proliferation. The purpose of this study was to observe whether low-energy neodymium (Nd: YAG) laser with appropriate parameters can affect the proliferation and migration of periodontal ligament stem cells (PDLSCs) through SDF-1/CXCR4 pathway.Methodsh PDLSCs were cultured and identified. CCK8 assay was used to detect the proliferation of h PDLSCs after different power (0, 0.25, 0.5, 1, and 1.5 W) Nd: YAG laser (MSP, 10 Hz, 30 s, 300 μ m) irradiation at 2th, 3rd,5th, and 7th days, and the optimal laser irradiation parameters were selected for subsequent experiments. Then, the cells were categorized into five groups: control group (C), SDF-1 group (S), AMD3100 group (A), Nd: YAG laser irradiation group (N), and Nd: YAG laser irradiation + AMD3100 group (N + A). the migration of h PDLSCs was observed using Transwell, and the SDF-1 expression was evaluated using ELISA andRT-PCR. The SPSS Statistics 21.0 software was used for statistical analysis.ResultsThe fibroblasts cultured were identified as h PDLSCs. Compared with the C, when the power was 1 W, the proliferation rate of h PDLSCs was accelerated (P < 0.05). When the power was 1.5 W, the proliferation rate decreased (P < 0.05). When the power was 0.25 and 0.5 W, no statistically significant difference in the proliferation rate was observed (P > 0.05). The number of cell perforations values as follows: C (956.5 ± 51.74), A (981.5 ± 21.15), S (1253 ± 87.21), N (1336 ± 48.54), and N + A (1044 ± 22.13), that increased significantly in group N (P < 0.05), but decreased in group N + A (P < 0.05). The level of SDF-1 and the expression level of SDF-1 mRNA in groups N and N + A was higher than that in group C (P < 0.05) but lower than that in group A (P < 0.05).ConclusionsNd: YAG laser irradiation with appropriate parameters provides a new method for endogenous regeneration of periodontal tissue. SDF-1/CXCR4 signaling pathway may be the mechanism of LLLT promoting periodontal regeneration.

Evaluation of dentinal tubule occlusion and pulp tissue response after using 980-nm diode laser for dentin hypersensitivity treatment.

To evaluate the effectiveness of the 980-nm diode laser for dentinal tubule occlusion, measure the intrapulpal temperature, and investigate the dental pulp response. The dentinal samples were randomly divided into G1-G7 groups: control; 980-nm laser irradiation (0.5 W, 10s; 0.5 W, 10s × 2; 0.8 W, 10s; 0.8 W, 10s × 2; 1.0 W, 10s; 1.0 W, 10s × 2). The dentin discs were applied for laser irradiation and analyzed by scanning electron microscopy (SEM). The intrapulpal temperature was measured on the 1.0-mm and 2.0-mm thickness samples, and then divided into G2-G7 groups according to laser irradiation. Moreover, forty Sprague Dawley rats were randomly divided into the laser-irradiated group (euthanized at 1, 7, and 14days after irradiation) and the control group (non-irradiated). qRT-PCR, histomorphology, and immunohistochemistry analysis were employed to evaluate the response of dental pulp. SEM indicated the occluding ratio of dentinal tubules in the G5 (0.8 W, 10s × 2) and G7 (1.0 W, 10s × 2) were significantly higher than the other groups (p < 0.05). The maximum intrapulpal temperature rises in the G5 were lower than the standard line (5.5 ℃). qRT-PCR showed that the mRNA expression level of TNF-α and HSP-70 upregulated significantly at 1day (p < 0.05). Histomorphology and immunohistochemistry analysis showed that, compared with the control group, the inflammatory reaction was slightly higher at the 1 and 7days (p < 0.05) and decreased to the normal levels at 14days (p > 0.05). A 980-nm laser at a power of 0.8 W with 10s × 2 defines the best treatment for dentin hypersensitivity in terms of compromise between the efficacy of the treatment and the safety of the pulp. The 980-nm laser is an effective option for treating dentin sensitivity. However, we need to ensure the safety of the pulp during laser irradiation.

Debonding of LDSVs utilising Er,Cr:YSGG laser irradiation with fractional technique: an in vitro study.

The removal of porcelain laminate veneers with rotary instruments could be accompanied by microfractures because differentiation of the veneer from the dental structure and resin cement is not a highly selective procedure. This can lead to scratches and overheating of the enamel and patient discomfort. Therefore, this in vitro research aimed to examine the effectiveness of the 2790 nm Er,Cr:YSGG laser utilizing a fractional technique to debond lithium disilicate veneer. Six groups of 30 extracted permanent bovine mandibular incisors were selected. Twenty-five samples, G1-5, (n = 5) laser-irradiated groups, and the last five samples (C) were considered the control group. The tested groups were irradiated with 3-5 W output power of Er,Cr:YSGG laser for time intervals of 50 s. During irradiation, the temperature in the pulp chamber was monitored using a thermocouple connected to a digital multilogger thermometer inside the sample's pulp chamber. Subsequently, the shear bond strength was measured for all groups. Furthermore, the remaining adhesive index was measured using a stereomicroscope, the area was analysed, and then transformed into scores. Finally, one untreated sample and two samples of the highest power value from laser-treated groups were examined using a scanning electron microscope (SEM) for their surface morphology. All debonding protocols were safe regarding intrapulpal temperature increment. The highest temperature elevation was recorded at 5 W, which increased by 1.7 °C. Considering the shear bond strength measurement, there was a significant reduction after laser irradiation for G1-5 compared with group C. Er,Cr:YSGG laser with a fractional technique can be used successfully for veneer removal. Besides safe temperature rising, veneers can be reused because there was neither a fractured specimen during the whole study nor major irregularities or cracks shown in SEM pictures analysis for the veneer surfaces; thus, they can be removed quickly, safely, and comfortably using Er,Cr:YSGG. © 2023 Australian Dental Association.

Evaluation and Comparison of Effect of Chlorhexidine Mouthwash and Laser on Survival of Human Gingival Fibroblasts - an In-Vitro Study

Introduction: Fibroblasts are the most important cells in wound healing. Chlorhexidine is the most widely used and investigated chemical plaque control agent after periodontal surgeries and Low-level laser therapy (LLLT), or photo biomodulation (PBM), refers to using photons to modulate biological activity. Since literature have shown promising results on fibroblasts viability following LASER irradiation, we aimed to evaluate and compare the effect of chlorhexidine mouthwash and LASER on survival of human gingival fibroblasts. Material and Methods: The experimental and control groups are as follows: Group I - Control, Group II - Fibroblasts treated with Chlorhexidine (Peridex), Group III - Fibroblasts irradiated with diode LASER. The cells in group II were treated with Chlorhexidine (Peridex-0.12%) whereas the cells in group III were irradiated diode LASER 5 seconds and cell viability was assessed using MTT Assay. Statistical Analysis: Comparison between all three groups was done by Kruskall Wallis ANOVA Inter group comparison (&gt;2 groups) was done using Kruskall Wallis ANOVA followed by pair wise comparison using Mann Whitney U test. Results: No change in the viability of cells in the control group, whereas the viability decreased to 50.4 % in group 2, which was statistically significant when compared with the control group (p&lt;0.01) and increased to 101.86 % in grp 3, but statistically insignificant when compared to control group (p&gt;0.01). Also, there was a statistically significant difference observed between group 2 and group 3 (p&lt;0.01). Conclusion: Chlorhexidine treatment to fibroblasts resulted in the decreased viability of the fibroblasts, and LASER irradiated cells, neither showed a significant reduction nor a significant increase in viability of fibroblasts. And when the two test groups, chlorhexidine treated and LASER irradiated groups, were compared there was a statistically significant difference observed.

Cellular, histological, and behavioral pathological alterations associated with the mouse model of photothrombotic ischemic stroke

BackgroundPhotothrombotic (PT) stroke model is a reliable method to induce ischemic stroke in the target site using the excitation of photosensitive agents such as Rose Bengal (RB) dye after light illumination. Here, we performed a PT-induced brain ischemic model using a green laser and photosensitive agent RB and confirmed its efficiency through cellular, histological, and neurobehavioral approaches. MethodsMice were randomly allocated into RB; Laser irradiation; and RB + Laser irradiation groups. Mice were exposed to a green laser at a wavelength of 532 nm and intensity of 150 mW in a mouse model after injection of RB under stereotactic surgery. The pattern of Hemorrhagic and ischemic changes were evaluated throughout the study. The volume of the lesion site was calculated using unbiased stereological methods. For investigation of neurogenesis, we performed double - (BrdU/NeuN) immunofluorescence (IF) staining on day 28 following the last- BrdU injection. To assess the effect and quality of ischemic stroke on neurological behavior, the Modified neurological severity score (mNSS) test was done on days 1, 7, 14, and 28 days after stroke induction. ResultsLaser irradiation plus RB induced hemorrhagic tissue and pale ischemic changes over the 5 days. In the next few days, microscopic staining revealed neural tissue degeneration, demarcated necrotic site, and neuronal injury. BrdU staining showed a significant number of proliferating cells in the periphery of the lesion site in the Laser irradiation plus RB group compared to the group (p < 0.05) while the percent of NeuN+ cells per BrdU- positive cells was reduced. Also, prominent astrogliosis was observed in the periphery of irradiated sites on day 28. Neurological deficits were detected in mice from Laser irradiation plus the RB group. No histological or functional deficits were detected in RB and Laser irradiation groups. ConclusionsTaken together, our study showed cellular and histologic pathological changes which are associated with the PT induction model. Our findings indicated that the undesirable microenvironment and inflammatory conditions could affect neurogenesis concomitantly with functional deficits. Moreover, this research showed that this model is a focal, reproducible, noninvasive and accessible stroke model with a distinctive demarcation similar to human stroke conditions.

Ex-vivo effects of propolis quantum dots-nisin-nanoquercetin-mediated photodynamic therapy on Streptococcus mutans biofilms and white spot lesions.

White spot lesions (WSLs) remain one of the most critical adverse sequelae of fixed orthodontic treatment, despite materials and techniques advances in orthodontics. WSLs seem to be a multi-factorial interaction including increased microbial plaque due to intrabuccal appliances that limit the oral-cleansing mechanism and change in the oral microbiome during fixed appliance wear. The aim of this study was to investigate the synergistic effect of propolis quantum dots (PQD), nisin (Nis), and quercetin nanoparticles (nQCT)-mediated photodynamic therapy (PQD-Nis-nQCT-mediated aPDT) in the eradication of Streptococcus mutans biofilms and the remineralization of WSLs ex-vivo. The cytotoxicity of PQD-Nis-nQCT composite on human gingival fibroblasts was evaluated using neutral red. Intracellular reactive oxygen species (ROS) generation following PQD-Nis-nQCT-mediated aPDT was measured. Enamel slabs were prepared and demineralized using a demineralization solution containing S. mutans. Demineralized enamel slabs were divided into 9 groups (n=10) and treated in the following groups: 1) Artificial saliva (negative control), 2) 2% neutral sodium fluoride gel (NSF; positive control or treatment control, 3) PQD, 4) Nis, 5) nQCT, 6) Nis-nQCT, 7) PQD-Nis-nQCT 8) Blue laser irradiation (light), 9) PQD-Nis-nQCT with irradiation (PQD-Nis-nQCT-mediated aPDT). Then, the surface changes, microhardness, and surface topography of the demineralized slabs were examined following each treatment using DIAGNOdent Pen reading, digital hardness tester, and SEM, respectively. After the determination of minimum biofilm eradication concentration (MBEC) of PQD, Nis, and nQCT by microtiter plate assay, the synergistic antimicrobial effects of PQD and Nis-nQCT were determined via evaluation of fractional biofilm eradication concentration (FBEC) index. The anti-biofilm effects of each treatment on S. mutans were assessed using a colorimetric assay. Thevirulence‑associated gtfB gene expression was assessed following PQD-Nis-nQCT-mediated aPDT byquantitative real‑time PCR. PQD-Nis-nQCT at 2048µg/mL had no significant cell cytotoxicity on human gingival fibroblasts compared to the control group (P > 0.05). A significantly increased (7.6 fold) in intracellular ROS was observed following PQD-Nis-nQCT-mediated aPDT (13.9 ± 1.41) when compared to the control (1.83 ± 0.13). Following each treatment, the microhardness of the demineralized enamel surface significantly increased except for the artificial saliva (negative) and blue laser irradiation groups. The highest change in microhardness improvement was detected in the PQD-Nis-nQCT-mediated aPDT group (P < 0.05). Also, DIAGNODent Pen reading revealed the highest significant improved change in the level of mineralization degree in the PQD-Nis-nQCT-mediated aPDT group. Nis and blue light irradiation groups, like the artificial saliva-treated demineralized enamel slabs (control group), did not lead to remineralization (P > 0.05). Also, the PQD-Nis-nQCT-mediated aPDT treatment results obtained from SEM revealed that remineralization of demineralized enamel slabs in that group has significantly improved compared to the others. Light-activated nQCT, PQD, Nis-nQCT, and PQD-Nis-nQCT composite significantly reduced pre-formed biofilms of S. mutans compared with unactivated forms of test materials. The relative expression level of the virulence gtfB gene was significantly decreased (7.53-fold) in the presence of PQD-Nis-nQCT-mediated aPDT (P < 0.05). PQD-Nis-nQCT-mediated aPDT can be used for the eradication of S. mutans biofilms and remineralization of WSLs. The found in vitro efficacy should be tested further through clinical studies.

Fabricating Aptamer-functionalized Ti3C2 therapeutic nanoplatform for targeted chemo-photothermal therapy of cancer

Aptamer (Apt) is a kind of recognition molecule with excellent affinity and high specificity. Transmembrane glycoprotein mucin (MUC1) is an important tumor biomarker overexpressed in MCF-7 tumor cells. MUC1 Apt (Apt-M) could specifically target MCF-7 tumor cells. Ti3C2 nanosheets with high photothermal conversion efficiency were considered as a promising therapeutic nanoplatform for tumor therapy. Doxorubicin (DOX) is a common anti-tumor drug. Herein, a novel DOX/Ti3C2/Apt-M therapeutic nanoplatform was successfully fabricated, which could specifically target MCF-7 tumor cells. As expected, the temperature of DOX/Ti3C2/Apt-M therapeutic nanoplatform raised rapidly under laser irradiation. Meanwhile, chemotherapy was triggered through multimodal stimuli-responsive drug release from the DOX/Ti3C2/Apt-M therapeutic nanoplatform under acidic environment and laser-induced local high temperature. Encouragingly, the MCF-7 cell viability of DOX/Ti3C2/Apt-M with laser irradiation was only 26.9%. The tumor surface temperature of MCF-7 xenograft mice in the DOX/Ti3C2/Apt-M + Laser group rose to about 58.3 °C, which was significantly higher than other laser irradiation groups. The experiments in vitro and in vivo indicated that the DOX/Ti3C2/Apt-M therapeutic nanoplatform can rapidly accumulate in MCF-7 tumors with excellent active targeting properties, and display superior tumor suppressive ability through combination therapy. This work provides a new idea of targeted tumor therapy based on Ti3C2 nanosheets.

Effects of Irradiation by Carbon Dioxide Laser Equipped With a Water Spray Function on Bone Formation in Rat Tibiae.

Irradiation of tissue with carbon dioxide (CO2) laser shows a characteristic thermal effect that causes vaporization of tissue in the target region. However, the thermal effect in places other than the target region induces tissue damage. Two methods are used: high reactive-level laser therapy (HLLT), aimed at surgical treatment, and low reactive-level laser therapy (LLLT), aimed at cell and tissue activation. In both, vaporization of tissue is induced by thermal damage. A water spray function may ameliorate thermal damage from CO2 laser irradiation. In this study, we irradiated CO2 laser on rat tibiae with or without a water spray function and examined the effects of this technique on bone metabolism. Bone defects were created in rat tibiae by dental bur in a Bur group and by laser in laser irradiation groups with (Spray group) and without (Air group) water spray function. At 1 week postoperatively, histological analyses of tibiae were performed using hematoxylin and eosin staining, immunohistochemical staining (IHC) with anti-sclerostin antibody, and 3-dimensional (3D) observation using micro-computed tomography. Histological findings and 3D observation confirmed induction of new bone formation following laser irradiation in both the Air and Spray groups. No bone formation was seen in the Bur group. IHC revealed that the activity of osteocytes in the region of irradiated cortical bone was markedly impaired in the Air group, but osteocyte impairment was ameliorated in the Spray group and absent in the Bur group. The water spray function appears effective in reducing thermal damage to tissues irradiated by CO2 laser. CO2 lasers with water spray function may be useful in bone regeneration therapy.

Çeşitli Kompozit Rezinlere Uygulanan Farklı Yüzey Pürüzlendirme Yöntemlerinin Porselen Bağlanma Dayanımına Etkisi: İn Vitro Çalışma

Objective: This study compares different surface conditioning methods applied to various composite surfaces in order to investigate the possible effects on composite-ceramic bond strength. It was aimed to increase the bond strength between flowable composite which is frequently used in the immediate dentin sealing procedure and ceramic surfaces. Material and Methods: Eighty flowable composite and eighty conventional composite discs were prepared with five different surface conditioning methods applied to the discs. The folllowing treatments were applied to the discs: orthophosphoric acid, air-flow, bur conditioning, Er:YAG laser irradition and an unconditioned control group. The composite disc surface roughness was measured with a profilometer. Composite and ceramic (Glass-ceramic blocks, e.max CAD, Ivoclar Vivadent AG, Liechtenstein) discs were then bonded with an adhesive resin cement. The shear bonding test was performed with an universal tester. Results: There was no statistical difference between the conditioning methods applied to flowable composites in terms of bond strength (p>0.05). However, a statistically significant difference was found between the conditioning methods applied to conventional composites regarding bond strength (p<0.05). The highest mean bond strength value was observed with ER:YAG laser conditioned conventional composites and was significantly higher than laser irradiated flowable composite groups. Conclusion: Our data shows that similar bond strength values are obtained when using either flowable or conventional composite resins. In addition, both conventional and flowable composite resins require surface conditioning to achieve reliable adhesion to porcelain material.