Cultured Human Fibroblast Biostimulation Using a 940 nm Diode Laser

Antiproliferative effect of low-level laser/ photobiomodulation on gingival fibroblasts derived from calcium channel blocker-induced gingival overgrowth

The aim of this study was to evaluate the antiproliferative properties of low-level laser therapy (LLLT) on gingival fibroblasts obtained from calcium channel blocker-induced gingival overgrowth (GO). Gingival fibroblasts of patients with GO were compared to healthy gingival fibroblasts (H). Both cells were exposed to LLLT (685 nm wavelength, 25mW power, diode laser) and compared to those not treated with LLLT. Cell proliferation and viability were measured with MTT assay at baseline and after 24 and 72 h. TGF-β1, CTGF, and collagen Type 1 levels were evaluated with Enzyme-Linked Immunosorbent Assay (ELISA). LLLT significantly decreased the proliferation of GO fibroblasts (p < 0.05) while leading to a significantly higher proliferation in H fibroblasts compared to the untreated cells (p < 0.05). GO cells showed significantly higher CTGF, TGF-β, and collagen Type 1 expression than the H cells (p < 0.05). LLLT significantly reduced CTGF levels in GO cells compared to the control group (p < 0.05). In H cells, CTGF and TGF-β levels were also significantly decreased in response to LLLT compared to the control group (p < 0.05). While LLLT significantly reduced collagen expression in the H group (p < 0.05), it did not significantly impact the GO cells. LLLT significantly reduced the synthesis of the growth factors and collagen in both groups with an antiproliferative effect on the gingival fibroblasts from calcium channel blocker-induced GO, suggesting that it can offer a therapeutic approach in the clinical management of drug-induced GO, reversing the fibrotic changes.

Photobiomodulation effects of pulsed and continuous wave near-infrared laser on the proliferation and migration of human gingival fibroblasts: An in vitro study

There are limited data on comparison of pulsed and continuous wave in photobiomodulation therapy (PBM). This study aimed to investigate the effect of PBM with 980 nm laser in pulsed and continuous wave on the proliferation and migration of human gingival fibroblasts (HGF) cells. Cultured HGF were divided into three main groups: (1) irradiated in pulsed mode (frequencies of 50 and 25 KHz; energy densities of 3 and 5 J/cm2 ), (2) irradiated in continuous mode (energy densities of 3.2 and 5.2 J/cm2 ), and (3) no irradiation as control group. HGF proliferation rate was measured by MTT assay at 24, 48, and 72 h post irradiation. In addition, HGF migration rate was measured by scratch test at 24 h post PBM. At 24 h, the group received continuous irradiation at 5.2 J/cm2 showed significantly higher proliferation compared with the control group (p = 0.012). At 48 and 72 h, the groups received continuous, and 50 Hz pulsed irradiation at energy densities of 5.2 and 5 J/cm2 respectively, had significantly higher HGF proliferation rates compared to the control (p < 0.05). Only the continuous irradiations were effective in significant increase of the cell migration. In conclusion, continuous PBM at energy density of 5.2 J/cm2 showed promising effect on HGF proliferation and migration.

The Benefits of Olive Oil for Skin Health: Study on the Effect of Hydroxytyrosol, Tyrosol, and Oleocanthal on Human Fibroblasts

Fibroblasts contribute to maintaining tissue integrity and homeostasis and are a key cell population in wound healing. This cell population can be stimulated by some bioactive compounds such as extra virgin olive oil (EVOO) polyphenols. The aim of this study was to determine the effects of hydroxytyrosol (htyr), tyrosol (tyr), and oleocanthal (ole) phenolic compounds present in EVOO on the proliferation, migration, cell cycle, and antigenic profile of cultured human fibroblasts. CCD-1064Sk human fibroblast cells were treated for 24 h with each polyphenol at doses ranging 10^-5 to 10^-9 M. Cell proliferation was evaluated using the MTT spectrophotometric technique, migration capacity by culture insert assay, and cell cycle and antigenic profile with flow cytometry. Cell proliferation was significantly increased by treatment with all compounds. The highest increases followed treatments with htyr or tyr at doses of 10^-5 or 10^-6 M and with ole at 10^-6 and 10^-7 M, and these compounds and doses were used for assays of antigenic profile, cell cycle, and migration. During the first few hours after treatment, increased fibronectin and α-actin expressions and greater cell migration were observed, with no cell cycle changes. In conclusion, these in vitro results suggest that phenolic compounds in EVOO might contribute to wound healing through action on fibroblasts related to tissue regeneration.

Cutaneous Photorejuvenation of Light Emitting Diodes via the Melatonin Membrane Receptor Pathway

BACKGROUND

Melatonin receptors are present in the human skin and retina. These receptors can be stimulated by light emitting diodes (LEDs) at specific wavelengths, thereby inducing cutaneous photorejuvenation. However, the underlying mechanism remains unclear.

OBJECTIVE

To evaluate the influence of LEDs at specific wavelengths on melatonin membrane receptor (MT1) and cutaneous photorejuvenation via the MT1 pathway in vitro.

METHODS

Normal human dermal fibroblasts (HDFs) were irradiated using LEDs at different wavelengths (410~940 nm) at a dose of 1 J/cm². MT1 activity was evaluated after melatonin stimulation and LED irradiation. Thereafter, the expressions of collagen (COL) and matrix metalloproteinases (MMPs), with and without luzindole (MT1/2 receptor antagonist), were investigated via semi-quantitative reverse transcription polymerase chain reaction (PCR), real-time PCR, western blotting, and enzyme-linked immunosorbent assay.

RESULTS

In HDFs, the MT1 mRNA and protein levels increased significantly in response to melatonin (dose, 50 nM) (p<0.01) and LED irradiation at 595, 630, 850, and 940 nm (p<0.01). LED irradiation up-regulated COL type I and down-regulated MMP-1. Compared to LED irradiation without luzindole, LED irradiation with luzindole produced no significant increase in COL type I mRNA and protein levels (p<0.01).

CONCLUSION

We found that LED irradiation induces collagen synthesis and MMP-1 inhibition in HDFs via MT1 activation. Additionally, multiple LED wavelengths (595, 630, 850, and 940 nm) stimulated MT1 in HDFs, unlike in the eyes, where only blue light induced plasma melatonin suppression. This suggests the possibility of the melatoninergic pathway in photorejuvenation.

Comparison of Pulsed and Continuous Wave Diode Laser at 940 nm on the Viability and Migration of Gingival Fibroblasts

Gingival fibroblasts have critical roles in oral wound healing. Photobiomodulation (PBM) has been shown to promote mucosal healing and is now recommended for managing oncotherapy-associated oral mucositis. This study examined the effects of the emission mode of a 940 nm diode laser on the viability and migration of human gingival fibroblasts. Cells were cultured in a routine growth media and treated with PBM (average power 0.1 W/cm² , average fluence 3 J/cm² , every 12h for 6 sessions) in one continuous wave (CW) and two pulsing settings with 20 % and 50 % duty cycles. Cell viability was assessed using MTT, and digital imaging quantified cell migration. After 48 and 72 hours, all treatment groups had significantly higher viability (n = 6, p < 0.05) compared to the control. The highest viability was seen in the pulsed (20% duty cycle) group at the 72-hour time point. PBM improved fibroblast migration in all PBM-treated groups, but differences were not statistically significant (n = 2, p > 0.05). PBM treatments can promote cell viability in both continuous and pulsed modes. Further studies are needed to elucidate the optimal setting for PBM-evoked responses for its rationalized use in promoting specific phases of oral wound healing.

940 nm diode laser induced differentiation of human adipose derived stem cells to temporomandibular joint disc cells

Background

Temporomandibular disorder (TMD) refers to a group of disorders that affect temporomandibular joint (TMJ) and its associated muscles with very limited treatment options. Stem cell research is emerging as one of the promising fields in the treatment of degenerative diseases. The ability of human adipose derived stem cells to differentiate into many cell types is driving special interest in several disease management strategies. Photobiomodulation has enhanced the role of these stem cells through their ability to promote cell proliferation and differentiation. Hence, this study examined the differentiation potential of human adipose derived stem cells (ADSCs) into fibroblasts and chondrocytes using a 940 nm diode laser for possible TMD therapy.

Materials and methods

ADSCs were cultured at different seeding densities and for different time intervals. After irradiation at 24, 48, 72 h, 1, 2 and 3 weeks, ADSC viability and morphological changes were assessed in groups with and without basic fibroblast growth factor. Additionally, the level of adenosine triphosphate (ATP) in the cells was also recorded. The differentiated fibroblasts and chondrocytes were characterized with flow cytometry and immunofluorescence techniques, at 1- and 2-weeks post-irradiation.

Results

Increased ATP proliferation and cell viability above 90% were observed in all post-irradiation experimental groups. Post irradiation results from flow cytometry and immunofluorescence at 1- and 2‐weeks confirmed the expression of chondrogenic and fibroblastic cell surface markers.

Conclusion

This study describes stimulatory techniques utilized to differentiate ADSCs into fibroblastic and chondrogenic phenotypes using diode lasers at 940 nm. The study proposes a new treatment model for patients with degenerative disc diseases of the TMJ. The study will offer new possibilities in tissue engineering and TMJ disc management through photobiomodulation of ADSCs using a 940 nm diode laser.

Repercussions of Bisphenol A on the Physiology of Human Osteoblasts

(1) Background: Bisphenol A (BPA) is an endocrine disruptor that is widely present in the environment and exerts adverse effects on various body tissues. The objective of this study was to determine its repercussions on bone tissue by examining its impact on selected functional parameters of human osteoblasts. (2) Methods: Three human osteoblast lines were treated with BPA at doses of 10^-5, 10^-6, or 10^-7 M. At 24 h post-treatment, a dose-dependent inhibition of cell growth, alkaline phosphatase activity, and mineralization was observed. (4) Results: The expression of CD54 and CD80 antigens was increased at doses of 10^-5 and 10^-6 M, while the phagocytic capacity and the expression of osteogenic genes (ALP, COL-1, OSC, RUNX2, OSX, BMP-2, and BMP-7) were significantly and dose-dependently reduced in the presence of BPA. (5) Conclusions: According to these findings, BPA exerts adverse effects on osteoblasts by altering their differentiation/maturation and their proliferative and functional capacity, potentially affecting bone health. Given the widespread exposure to this contaminant, further human studies are warranted to determine the long-term risk to bone health posed by BPA.

In Vitro Effect of 810 nm and 940 nm Diode Laser Irradiation on Proliferation of Human Gingival Fibroblasts and Expression of Procollagen Gene

Factors promoting fibroblast proliferation and collagen synthesis can subsequently enhance wound healing. This study aimed to assess the effect of 810 and 940 nm diode laser on fibroblast proliferation and procollagen gene expression. In this study, human gingival fibroblasts were cultured in Dulbecco's modified Eagle's medium and underwent 810 and 940 nm diode laser irradiation once, twice, thrice and four times at 1, 3, 5 and 7 days after culture. The methyl thiazolyl tetrazolium assay was performed to assess the proliferation while the real-time polymerase chain reaction was performed to assess the expression of procollagen gene at the mRNA level. We applied Two-way ANOVA and Tukey's test for analysis. Wavelength had no significant effect on proliferation of gingival fibroblasts, but increasing the number of irradiation sessions of both wavelengths increased the proliferation of human gingival fibroblasts. Significant differences were noted in the number of human gingival fibroblasts between groups irradiated 1 and 4 and also 2 and 4 times. Procollagen gene was well expressed in all groups but its expression was significantly higher in 940 nm laser group after 4 irradiation cycles. 4 times radiation of 940 nm laser seems to be more effective than all others.

Transmission of 940 nm diode laser to the radicular area during its application as root canal disinfectant

To measure the transmitted laser power in the coronal, middle and apical root thirds during vertical and horizontal irradiation of laser. 14 mm length whole roots and longitudinal root sections were irradiated using a 940 nm diode laser with 0.5 W in continuous mode for 5 s. A power detector was placed in front of the root apex for the vertical transmitted power measurement and placed laterally to root surface for the horizontal transmission experiment. The transmitted power from the root apex vertically was 53% of the irradiated power, while for the horizontal transmission experiment for the coronal, middle and apical root thirds were 25.6%, 40.4% and 41.3%, respectively. Irradiation of root canals with 940 nm laser power can be transmitted during vertical irradiation in more than 50% of the samples, whereas less transmission happens with horizontal irradiation at apical and middle root third than coronal.

Antimicrobial properties of olive oil phenolic compounds and their regenerative capacity towards fibroblast cells

Some micronutrients of vegetable origin are considered potentially useful as wound-healing agents because they can increase fibroblast proliferation and differentiation.

THE AIM OF THIS STUDY

was to evaluate the regenerative effects of selected olive oil phenolic compounds on cultured human fibroblasts and explore their antimicrobial properties.

MATERIAL AND METHODS

The CCD-1064Sk fibroblast line was treated for 24 h with 10^-6M luteolin, apigenin, ferulic, coumaric acid or caffeic acid, evaluating the effects on cell proliferation by using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) spectrophotometric assay; the migratory capacity by the scratch assay and determining the expression of Fibroblast Growth Factor (FGF), Vascular Endothelial Growth Factor (VEGF), Transforming Growth Factor- β1 (TGFβ1), Platelet Derived Growth Factor (PDGF), and Collagen Type I (COL-I) genes by real-time polymerase chain reaction. The antimicrobial capacity of the polyphenols was evaluated by the disc diffusion method.

RESULTS

All compounds except for ferulic acid significantly stimulated the proliferative capacity of fibroblasts, increasing their migration and their expression of the aforementioned genes. With respect to their antimicrobial properties, treatment with the studied compounds inhibited the growth of Staphylococcus aureus, Staphylococcus epidermidis, Escherichia coli, Proteus spp., and Candida Albicans.

CONCLUSIONS

The phenolic compounds in olive oil have a biostimulatory effect on the regeneration capacity, differentiation, and migration of fibroblasts and exert major antibacterial activity. According to the present findings, these compounds may have a strong therapeutic effect on wound recovery.

Assessment of Human Gingival Fibroblast Proliferation after Laser Stimulation In Vitro Using Different Laser Types and Wavelengths (1064, 980, 635, 450, and 405 nm)-Preliminary Report

PURPOSE

to assess the effect of photobiomodulation (PBM) on human gingival fibroblast proliferation.

METHODS

The study was conducted using the primary cell cultures of human fibroblasts collected from systemically healthy donors. Three different laser types, Nd:YAG (1064 nm), infrared diode laser (980 nm), and prototype led laser emitting 405, 450, and 635 nm were used to irradiate the fibroblasts. Due to the patented structure of that laser, it was possible to irradiate fibroblasts with a beam combining two or three wavelengths. The energy density was 3 J/cm2, 25 J/cm2, 64 J/cm2. The viability and proliferation of cells were determined using the (Thiazolyl Blue Tetrazolium Blue) (MTT) test conducted 24, 48, and 72 h after laser irradiation.

RESULTS

The highest percentage of mitochondrial activity (MA = 122.1%) was observed in the group irradiated with the 635 nm laser, with an energy density of 64 J/cm2 after 48 h. The lowest percentage of MA (94.0%) was observed in the group simultaneously irradiated with three wavelengths (405 + 450 + 635 nm). The use of the 405 nm laser at 25 J/cm2 gave similar results to the 635 nm laser.

CONCLUSIONS

The application of the 635 nm and 405 nm irradiation caused a statistically significant increase in the proliferation of gingival fibroblasts.

Effect of Photobiomodulation on Secretion of IL-6 and IL-8 by Human Gingival Fibroblasts In Vitro

Objective: The aim of this study was to evaluate the effects of 940-nm diode laser irradiation on proinflammatory cytokine secretions [interleukin (IL)-6 and IL-8] by human gingival fibroblasts in vitro. Background: Photobiomodulation has been routinely used in many dental procedures; however, the exact biological action mechanism of photobiomodulation and its therapeutic benefits have not been established. Methods: Cells derived from systemically healthy individuals were treated with three different laser parameters-6 J for 20 sec [0.84 J/cm² (0.04 W/cm²)], 10 J for 20 sec [1.4 J/cm² (0.07 W/cm²)], and 14 J for 20 sec [1.97 J/cm² (0.09 W/cm²)]-in the presence and absence of 1 μg/mL lipopolysaccharide (LPS) stimulation. Laser irradiations were carried out by a 940-nm diode laser device in continuous pain therapy mode with a deep tissue handpiece. Changes in cell viability, cytokine secretions, and mitogen-activated protein kinase pathway expressions were investigated, and results were compared with negative (medium) and positive control (1 μg/mL LPS) groups. The data obtained were statistically analyzed by the Mann-Whitney U test for pairwise comparisons among groups at the 0.05 level of significance. Results: Laser therapy with 0.84-1.4 J/cm² amplified IL-6 and IL-8 secretions, whereas 1.97 J/cm² suppressed IL-6 and IL-8 release in LPS-stimulated cells. Cell viability did not show a variation with photobiomodulation. Conclusions: These results demonstrate that photobiomodulation can alter IL-6 and IL-8 release, with cytokine suppression potency at a relatively high dose, as demonstrated previously. However, in contrast, we found that a low level of stimulation (6 J) in the presence of inflammation (LPS stimulation) may further enhance IL-6 and IL-8 release. We also found that p38 and ERK1/2 pathways are activated by LPS as well as by photobiomodulation.

Effects of Therapeutic Doses of Celecoxib on Several Physiological Parameters of Cultured Human Osteoblasts

Non-steroidal anti-inflammatory drugs (NSAIDs), including cyclooxygenase-2 (COX-2)-selective NSAIDs, are associated with adverse effects on bone tissue. These drugs are frequently the treatment of choice but are the least studied with respect to their repercussion on bone. The objective of this study was to determine the effects of celecoxib on cultured human osteoblasts. Human osteoblasts obtained by primary culture from bone samples were treated with celecoxib at doses of 0.75, 2, or 5μM for 24 h. The MTT technique was used to determine the effect on proliferation; flow cytometry to establish the effect on cell cycle, cell viability, and antigenic profile; and real-time polymerase chain reaction to measure the effect on gene expressions of the differentiation markers RUNX2, alkaline phosphatase (ALP), osteocalcin (OSC), and osterix (OSX). Therapeutic doses of celecoxib had no effect on osteoblast cell growth or antigen expression but had a negative impact on the gene expression of RUNX2 and OSC, although there was no significant change in the expression of ALP and OSX. Celecoxib at therapeutic doses has no apparent adverse effects on cultured human osteoblasts and only inhibits the expression of some differentiation markers. These characteristics may place this drug in a preferential position among NSAIDs used for analgesic and anti-inflammatory therapy during bone tissue repair.

Human Fibroblast Gene Expression Modulation Using 940 NM Diode Laser

Low-Level Laser Therapy is used as regenerative therapy in different clinical fields. This is due to its photobiomodulation effect via cell signaling on different cell populations, Including fibroblasts, cells involved in tissue regeneration and healing. The aim was to analyze the effect of 940 nm diode laser on the gene expression of different markers involved in fibroblast growth, differentiation, and migration. Real-time polymerase chain reaction (q-RT-PCR) was used to quantify the expression of fibroblast growth factor (FGF), connective tissue growth factor (CTGF), vascular-endothelial growth factor (VEGF), transforming growth factor β1 (TGF-β1), TGFβ-receptors (TGFβR1, TGFβR2, and TGFβR3), discoidin-domain receptor-2 (DDR2), matrix metalloproteinase-2 (MMP2), α-actin, fibronectin, decorin, and elastin on human fibroblast, treated with single dose (T1) or two doses (T2) of diode laser at 0.5 Watts and 4 J/cm². A significant increase in the expression of FGF, TGF-β1, TGFβR1, TGFβR2, α-actin, fibronectin, decorin, DDR2 and MMP2 was observed after both treatments. A decrease was observed in expression of elastin (T1 and T2), and CTGF (T2). These changes underlie the biostimulatory effect of laser on fibroblasts, which translates into an increase in short-term proliferation and in long-term differentiation to myofibroblasts. These data support the therapeutic potential of diode laser for wound repair.

Impact of bisphosphonates on the proliferation and gene expression of human fibroblasts

The aim of this study was to elucidate the role of fibroblasts in bisphosphonate-related osteonecrosis of the jaw (BRONJ), evaluating the effect of zoledronate, alendronate, and ibandronate on the proliferation of fibroblasts and on their expression of genes essential for fibroblast physiology. Human CCD-1064Sk epithelial fibroblast cells were incubated in culture medium with 10^-5, 10^-7, or 10^-9 M zoledronate, alendronate, or ibandronate. The proliferative capacity of fibroblasts was determined by spectrophotometry (MTT) at 24 of culture. Real-time polymerase chain reaction (RT-PCR) was used to study the effects of BPs at a dose of 10^-9 M on the expression of FGF, CTGF, TGF-β1, TGFβR1, TGFβR2, TGFβR3, DDR2, α-actin, fibronectin, decorin, and elastin. Fibroblasts proliferation was significantly increased at the lowest dose (10^-9M) of each BP but was not affected at the higher doses (10^-5 and 10^-7M). The proliferation increase may be related to the rise in TGF-β1 and TGFβR1 expression detected after the treatment of cells with 10^-9M of zoledronate, alendronate, or ibandronate. However, the expression of CTGF, DDR2, α-actin, fibronectin, and decorin decreased versus controls. The results of this in vitro study indicate that a very low BP dose (10^-9 M) can significantly affect the physiology of fibroblasts, increasing their proliferative capacity and modulating the expression of multiple genes involved in their growth and differentiation.