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Objective:To investigate the effect of different incubation time of aminolevulinic acid (ALA) on photodynamic inhibition of Propionibacterium acnes biofilms. Methods:Propionibacterium acnes biofilms were formed in 24-well plates with pre-placed cell slides and 96-well plates. The formation of the biofilm structure was observed by confocal laser scanning microscopy (CLSM) , and the growth activity of the biofilm was assessed by the tetrazolium salt XTT assay. The in vitro successfully constructed biofilm models were divided into 6 groups: negative control group receiving neither ALA treatment nor LED radiation, ALA group incubated with ALA alone for 30 minutes, LED group receiving LED radiation alone, ALA-PDT1 group, ALA-PDT2 group and ALA-PDT3 group incubated with ALA for 15, 30 and 60 minutes respectively followed by LED radiation. After the treatment, CLSM was performed to observe the biofilm structure, as well as to determine the dead/living bacteria ratio, and XTT assay to assess the growth activity of the biofilm. Differences among groups were analyzed using one-way analysis of variance and least significant difference- t test. Results:CLSM showed that the Propionibacterium acnes biofilm model was successfully constructed in vitro. The dead/living bacteria ratios were 0.90 ± 0.16, 1.75 ± 0.19, and 2.57 ± 0.32 in the ALA-PDT1 group, ALA-PDT2 group and ALA-PDT3 group respectively, which were significantly higher than the dead/living bacteria ratio in the negative control group (0.31 ± 0.01; t= 55.56, 138.62, 74.64, respectively, all P<0.001) ; the biofilm viability value was significantly lower in the ALA-PDT1 group, ALA-PDT2 group and ALA-PDT3 group (0.35 ± 0.02, 0.26 ± 0.02, 0.18 ± 0.01, respectively) than in the negative control group (0.43 ± 0.00; t= 35.66, 2.64, 110.96, respectively, all P < 0.001) . CLSM showed that the structure of the Propionibacterium acnes biofilm was destroyed under the action of ALA-PDT, and the destruction was aggravated with the prolongation of incubation time of ALA. Conclusion:The prolongation of incubation time of ALA can enhance the inhibitory effect of ALA-PDT on Propionibacterium acnes biofilms.
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To investigate the effect of 5-aminolevulinic acid photodynamic therapy (ALA-PDT) on () biofilm. biofilms were constructed on a cell slide and treated with ALA-PDT.According to different light doses,the biofilms were divided into six groups:ALA-PDT group [ALA-PDT1 (50 J/cm),ALA-PDT2 group (100 J/cm),ALA-PDT3 group (200 J/cm)],ALA-only group (ALA group),light-only group (LED),and a negative control group (ALA-PDT-group).The biofilm structure and the ratio of the dead bacteria/live bacteria were observed using a laser confocal microscope (CLSM).Biofilm viability was measured using the XTT assay. CLSM showed that the biofilm structures of ALA group and LED group were not significantly different from that of ALA-PDT-group,whereas the biofilm structure was more seriously damaged in ALA-PDT1 group,ALA-PDT2 group,and ALA-PDT3 group than in the ALA-PDT-group.The ratios of the dead/live bacteria in ALA-PDT-group,ALA group,LED group,ALA-PDT1 group,ALA-PDT2 group,and ALA-PDT3 group were 0.350±0.033, 0.305±0.046, 0.330±0.032, 1.525±0.439, 2.293±0.148 and 3.092±0.189,respectively.ALA group(=0.003, =1.000)and LED group(=-0.025, =1.000)did not significantly differ from the ALA-PDT-group.However,the ratio of dead/live bacteria in ALA-PDT-group was significantly lower than those in ALA-PDT1 group (=-0.162, <0.001),ALA-PDT2 group (=-0.254, <0.001),and ALA-PDT3 group (=-0.352, <0.001).The values of the XTT assay were were 0.462±0.028,0.465±0.044,0.437±0.047,0.301±0.040,0.207±0.001,and 0.110±0.007,respectively,in ALA-PDT-group,ALA group,LED group,ALA-PDT1 group,ALA-PDT2 group,and ALA-PDT3 group.Although the values of XTT assay in ALA(=-0.044, =1.000)and LED groups (=-0.020, =1.000)did not significantly differ from that in ALA-PDT-group,it was significantly higher in ALA-PDT-group than in ALA-PDT1 group (=1.175, <0.001),ALA-PDT2 group (=1.942, <0.001),and ALA-PDT3 group (=-0.352, =2.742, <0.001). ALA-PDT has an inhibitory effect on biofilm.ALA-PDT destroys biofilm structure and inhibits biofilm viability.
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Aminolevulinic Acid , Biofilms , Photochemotherapy , Photosensitizing Agents , Propionibacterium acnesABSTRACT
Objective:To compare the efficacy and safety of picosecond alexandrite laser and ultrapulsed fractional CO 2 laser for the treatment of facial atrophic acne scars in a prospective, split-face clinical trial. Methods:From October 2015 to October 2017, patients with facial symmetrical atrophic acne scars were enrolled from Department of Cosmetic Laser Surgery, Hospital for Skin Diseases, Chinese Academy of Medical Sciences and Peking Union Medical College. The left side of the face of the patients was treated with ultrapulsed fractional CO 2 laser, and the right side of the face was treated with a 755-nm picosecond alexandrite laser with a diffractive lens array. All patients received 3 sessions of laser treatment at a 2-month interval. The severity of scars was evaluated by 2 dermatologists before and after the treatment according to the ECCA grading scale (échelle d′évaluation clinique des cicatrices d′acné) , and clinical efficacy was self-assessed by the patients according to a 4-point scale. Pain scores and adverse reactions were recorded. Paired t test was used to compare ECCA scores and pain scores between the 2 sides of the face, as well as between pre- and post-treatment values, and Wilcoxon rank sum test was used to compare the 4-point scores between the 2 groups. Results:There was no significant difference in the ECCA score between the picosecond laser side and the fractional laser side before the treatment ( t = 1.06, P = 0.300) , while the ECCA score was significantly higher in the picosecond laser side than in the fractional laser side after 3 sessions of treatment (70.98 ± 21.48 vs. 58.04 ± 17.63, t = 3.76, P = 0.001) . Compared with the pre-treatment severity score of scars, the improvement in severity score was significantly less in the picosecond laser side than in the fractional laser side (2.21 ± 1.09 vs. 2.83 ± 1.11, z = 2.70, P = 0.007) . Compared with the fractional laser side, the picosecond laser side showed significantly lower pain scores (3.71 ± 0.62 vs. 6.23 ± 1.06, t = 11.93, P < 0.001) and less adverse reactions, which mainly manifested as transient erythema and edema. Conclusions:Both picosecond alexandrite laser and fractional CO 2 laser can effectively improve atrophic acne scars. Fractional CO 2 laser is more effective, but picosecond alexandrite laser has less adverse effects.
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Objective To evaluate the efficacy and safety of a 755 nm picosecond Alexandrite la-ser with a diffractive lens array in the treatment of facial photoaged skin .Methods Twenty-six pa-tients with facial photoaging were recruited and received 3 treatments at 4-week intervals .Laser energy was applied over the entire face at a fixed spot size of 6 mm ,with a fluence of 0 .71 J/cm2 and 5Hz . Blinded clinical assessment was performed by 2 independent dermatologists on a 5-point global pho-toaging scale (GPS) .Patients were also questioned on the extent of improvement of rhytides ,skin tightening ,and complexion with a 4-point global aesthetic improvement scale (GAIS) and satisfaction . Adverse events were also evaluated .Results Twenty-six patients completed the treatment .Compared with the baseline ,there was a significant improvement in facial photoaged skin after 3 treatments ,and these positive outcomes were maintained up to the 3-month follow-up ,according to the GPS and GAIS scores .Moderate pain and transient erythema were observed as the two main discomforts associated with the treatment .Most patients were satisfied with the treatment .Conclusions This 755 nm pico-second Alexandrite laser with a diffractive lens array optic is effective in the treatment offacial pho -toaged skin ,and the therapy also seems safe and well tolerated .
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Objective To compare the clinical efficacy and adverse effects of photodynamic therapy (PDT) versus pulsed dye laser(PDL)for the treatment of port wine stains(PWS). Methods Forty?five patients with PWS were enrolled in this study. The PWS lesions in each patient were randomly divided into PDT and PDL areas. Hematoporphyrin monomethyl ether of 5 mg/kg was injected intravenously into the PDT area protected from light, followed by 20?minute irradiation with a 532?nm, solid?state, continuous?wave laser(power density:80-100 mw/cm2;spot diameter: 7 cm)10 minutes later. The PDL area was treated with a single session of 595?nm pulsed dye laser radiation(spot diameter:7 mm;pulse width:10 ms;energy density:10-12 J/cm2). The interval between PDT and PDL treatment was no shorter than two months. Follow up visits were scheduled on day 4 and week 8 after each treatment. Adverse reactions were recorded, and photographs were taken before and 8 weeks after the treatment for evaluation of lesion regression. Results In the case of PDT area, 10 cases(22.22%)were nearly cured, 22(48.89%)achieved marked improvement, 9(20.00%)improvement, 4(8.89%)no improvement. As far as the PDL area is concerned, 6 cases(13.33%)were nearly cured, 16(35.56%)achieved marked improvement, 18(40.00%)improvement, and 5 (11.11%)no improvement. The response rate was significantly higher in the PDT area than in the PDL area(Z=2.48, P0.05). Conclusion For the treatment of PWS, both PDT and PDL are effective and safe, and single?session PDT appears to be superior to single?session PDL.
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Objective To investigate the effect of adenovirus-mediated IL-24 (Ad-IL-24)gene expression on the apoptosis in a human squamous cell carcinoma cell line COLO 16, and to explore the underlying molecular mechanism. Methods Cultured COLO 16 cells were divided into two groups to be transfected with an adenovirus vector carrying the IL-24 gene (Ad-IL-24 group)or green fluorescent protein (Ad-GFP group), while those receiving no treatment served as the control group. After culture for different durations, qPCR was performed to quantify IL-24 gene expression, methyl thiazolyl tetrazolium (MTT) assay to evaluate the proliferative activity of COLO 16 cells, flow cytometry to detect the apoptosis of COLO 16 cells, laser scanning confocal microscopy (LSCM) to observe the morphological changes of COLO 16 cells, Western blot to determine the levels of Bax and Bcl-2 proteins and to evaluate the activation of caspase-3, qPCR to determine the levels of Bax and Bcl-2 mRNAs, an immunofluorescence assay to observe the expression of Bax and Bcl-2 proteins. Statistical analysis was carried out by a two-sample t-test with the SPSS 19.0 software. Results MTT assay showed that the proliferation of COLO 16 cells in the Ad-IL-24 group was significantly inhibited as early as 4 days after the transfection; thereafter, the inhibitory effect increased in a time-dependent manner, and peaked on day 6(P0.05). Flow cytometry revealed that the apoptosis rate was significantly higher in the Ad-IL-24 group(13.10%± 0.92%)than in the control group(3.69%± 0.36%, P0.05). LSCM demonstrated that the apoptosis of COLO 16 cells was accelerated in the Ad-IL-24 group. The immunofluorescence assay, Western blot and qPCR all showed that the mRNA and protein expressions of Bax were increased, but those of Bcl-2 were decreased in the Ad-IL-24 group compared with the Ad-GFP group and control group. Moreover, Western blot showed a protein band that could specifically bind to the anti-cleaved caspase-3 antibody in the Ad-IL-24 group, but not in the Ad-GFP group or control group. Conclusions Ad-IL-24 can induce apoptosis in human COLO 16 squamous cell carcinoma cells, probably by up-regulating Bax expression, down-regulating Bcl-2 expression, and activating caspase 3.
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Objective To evaluate the efficacy and safety of AlumaTM functional aspiration controlled electrothermal stimulation (FACES) radiofrequency in the treatment of skin wrinkles and laxity on the face and neck. Methods A total of 30 volunteers with aging skin were recruited in the study. All volunteers were treated with AlumaTM FACES radiofrequency for 6 times at 2-week interval. Photographs were taken for volunteers before every treatment and 1 month after the last treatment. Improvement in lesions was objectively assessed by two separate physicians based on the photographs of volunteers taken before the first,fourth and sixth treatment, and 1 month after the last treatment. Patient satisfaction was measured by ques-tionnaire. Adverse effects were recorded. Results Totally, 24 volunteers completed the treatment. Improve-ment of lesions was achieved in 66.7% of the volunteers after 3 treatments, 90.5% after 5 treatments, and 94.4% one month after the last treatment. About 50% of the volunteers were satisfied with the effect after 3 treatments, 90.5% after 5 treatments, and 100% one month after the last treatment. Slight purpura was the most common side effect. Conehusion Radiofrequency therapy is effective for skin wrinkles and laxity on the face and neck, without obvious side effect.
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Objective To evaluate the long-term effects and safety of diode laser in hair removal.Methods A retrospective study was conducted.In this study,350 patients with hypertrichosis were treated by an 800-nm diode laser with a pulse duration of 30 ms for various sessions.Two groups were divided based on the treatment sessions:group A receiving 6(≥4 for axillae)or more treatments,group B less than 6(＜4 for axillae)treatments.Patients were followed up for 8 months to 3 years(mean 22.5 months)by return visit or telephone.Evaluation of efficacy and side effects were performed.Results Follow-up and evaluation were completed in 235 patients,and a total of 375 sites treated.After 2-18 treatments,a total effective rate of 80.53%(302/375)was achieved.Significant higher effective rates were observed in group B compared with group A at all sites 86.84%(33/38)vs 35.00%(7/20)on the lips,68.42%(26/38)vs 30.77%(4/13)on the face and neck,92.00%(46/50)vs 55.56%(5/9)in lower extremities,86.96%(20/23)vs 50.00%(4/5)on the trunk.93.81%(91/97)vs 55.56%(5/9)at the axillae,92.16%(47/51)vs 73.68%(14/19)in the upper extremities(all P＜0.05),Side effects were noted in only 6 cases,including hyperpigmentation,itching,and development of follicular papules,blisters and white hair.Neither hypopigmentation nor scarring was observed.Conclusions Diode laser system is effective and safe for hair removal.The effect varies with lesional sites and treatment sessions.
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Objective To investigate the skin reactions induced by to pical 0.1% tretinoin and its vehicle in mice.Methods 0.1% tretinoin and its v ehicle were applied separately on mice backs,once a day for 30 days.The skin r eactions,including erythema and scaling,were observed macroscopically and meas ured by biological instruments.Results Macroscopically the skin reactions of erythema and scaling induced by topical tretinoin occurred on day 3 after applic ation,reached its peak on day 6 and disappeared on day 12,and neither erythema nor abnormal scaling appeared in spite of continuing application until day 30.The erythema value measured was enhanced significantly on day 1 after applicatio n,reached its peak on day 6,maintained until day 9 and became normal on day 11.From then to day 30,it maintained at the normal level.The scaling value measu red enhanced significantly on day 3 after application,reached its peak on day 9 and became normal on day 27.Topical application of the vehicle induced neither skin reaction nor any change of erythema and scaling value.Conclusions Topic al application of 0.1% tretinoin induces skin reaction characterized by erythema and scaling.The reaction,transient but not related to the vehicle,experience s a process of "occurrence-peak-disappearance".