[Influence of ALA-PDT on fibroblast cells from hypertrophic scars].

OBJECTIVE: To determine the effect of ALA-PDT on fibroblast cells from hypertrophic scars in vitro, and to identify proper dosage of photosensitizer and energy level of laser light. METHODS: Fibroblast cells from hypertrophic scars were cultured in vitro. ALA (5-aminolevulnilic acid) was added into the culture fluid with different concentrations. Then the cultured cells were exposed to He-Ne laser light (PDT) with different energy levels. The cell inhibition rate was measured with CCK-8 method. The expression of PCNA in fibroblast cells was detected after cultured with ALA-PDT, which was selected according to the proper dosage of ALA and laser light from the result of CCK-8. RESULTS: No obvious inhibition effect was detected with laser light or photosensitizer alone on fibroblast cells from hypertrophic scars. The inhibition effect appeared when ALA and PDT applied simultaneously, and the inhibition rate increased with the dosage of photosensitizer and the energy level of laser light. Maximal inhibition effect reached with 20 J/cm2 laser light exposure and 0.5 mmol/L of ALA, the expression of PCNA of ALA-PDT group is lower than control group in this condition (30.33 +/- 2.08 vs. 78.33 +/- 3.79, P < 0.05). CONCLUSION: The inhibition effect of ALA-PDT on fibroblast cells from hypertrophic scars increases with the dosage of photosensitizer and the energy level of He-Ne laser light. The proper dosage of ALA is 0.5 mmol/L along with 20 J/cm2 laser light exposure.

[Study on the inhibitory effect of ALA-PDT on the proliferation of fibroblasts from keloid].

OBJECTIVE: To investigate the effects of ALA-PDT on the proliferation of fibroblasts from keloid in vitro, and to find the most efficient concentration of photosensitizer and the energy of He-Ne laser light. METHODS: The fibroblast cells from keloid cultured in vitro were divided into blank control group, laser light group (only with different dose energy of He-Ne laser light), photosensitizer group(only with different concentration of ALA) and ALA-PDT group (treated by photosensitizer and laser light). After the above treatments were finished, the inhibition rate of each group was measured with MTT method. RESULTS: There is no obvious inhibitory effect on the fibroblast cells from keloid in laser light group and photosensitizer group, In ALA-PDT groups, when the concentration of ALA and the dose of energy of He-Ne laser light reached some extent (>0.125 mmol/L and >10 J/cm2 respectively), the inhibitory effect of ALA-PDT kept rising with the increase of the concentration of ALA and the energy of He-Ne laser light. The most appropriate concentration for ALA is 0.25 mmol/L, while the energy for He-Ne laser light is 40 J/cm2. CONCLUSION: The inhibitory effect, of ALA-PDT on the proliferation of fibroblasts from keloid could be enhanced with the increase of photosensitizer concentration and laser light energy.

Characterization and photocatalytic property of Pd/TiO2 with the oxidation of gaseous benzene.

Increasing environmental pollution caused by the volatile organic compounds due to their toxicity is a matter of great concern. So it is crucial to develop processes which can destroy these compounds effectively. It has been found that the photocatalytic activity of TiO(2) towards the decomposition of gaseous benzene can be greatly enhanced by loading Pd on the surface of TiO(2). The results show that the optimum palladium loading is 0.25wt.%. The prepared photocatalysts were characterized by XRD, UV-vis diffuse reflectance and XPS. XRD results indicate that no peaks of Pd are detected in the 2theta region from 10 degrees to 90 degrees . Pd/TiO(2) absorbs much more light than TiO(2) in the visible light region. The XPS spectrum shows that there are Ti, O, C and Pd elements on the surface of the Pd/TiO(2), the binding energy values of Ti2p of 0.25%Pd/TiO(2) transfer to a lower value. In addition, the photocatalytic performance of 0.25%Pd/TiO(2) was investigated, the result illustrates that 0.25%Pd/TiO(2) demonstrates 2.32 times the photocatalytic activity of pure TiO(2). The reason of promotion of photocatalytic performance was discussed.

Remove cooking fume using catalytic combustion over Pt/La-Al2O3.

Five monolithic catalysts with low noble metal content were prepared by immerge method (Pt/gamma-Al2O3, Pt/La-Al2O3, Pt/YSZ-Al2O3, Pt+Pd/La-Al2O3 and Pd/La-Al2O3) and their activity measurements were carried out in a conventional fixed-bed flow reactor. The results show that La-Al2O3 can promote activity of the prepared catalysts and can decrease the complete conversion temperature of cooking fume. The Pt/La-Al2O3 catalyst has the highest activity and can be applied in wide range of gas hourly space velocity (GHSV). Some characterizations (XRD, TPR) were carried out with the objective to explain differences in catalytic behaviors. The prepared catalyst showed a great potential for application.