The apoptosis of cancer cells is associated with changes in the important cell properties including morphology, surface roughness and stiffness. Therefore, the changes in morphology and biophysical properties can be a good way of evaluating the anticancer activity of a drug. This study examined the effect of paclitaxel on the properties of Ishikawa and HeLa cells using atomic force microscopy (AFM), and the relationship between the changes in morphology and the biophysical properties and apoptosis was discussed. The viability and proliferation of the cells were analyzed using the methylthiazol tetrazolium (MTT) method and a TUNEL assay to confirm cellular apoptosis due to a paclitaxel treatment. AFM observations clearly showed the apoptotic morphological and biophysical changes in Ishikawa and HeLa cells. After the paclitaxel treatment, the cell membrane was torn and holed, the surface roughness was increased, and the stiffness was decreased. These changes were observed more apparently after a 24 h treatment and in Ishikawa cells compared to HeLa cells. The MTT and TUNEL assays results revealed the Ishikawa cells to be more sensitive to paclitaxel than HeLa cells and definite apoptosis occurred after a 24 h treatment. These results showed good agreement with the AFM results. Therefore, research on the morphological and biophysical changes by AFM in cancer cells will help to evaluate the anticancer activities of the drugs.
We introduce a novel, facile, rapid, low-cost, highly reproducible, and power-free synthesizable fabrication method of paper-based silver nanoparticle (AgNP) immersed surface-enhanced Raman scattering (SERS) platform, known as the successive ionic layer absorption and reaction (SILAR) method. The rough and porous properties of the paper led to direct synthesis of AgNPs on the surface as well as in the paper due to capillary effects, resulting in improved plasmon coupling with interparticles and interlayers. The proposed SERS platform showed an enhancement factor of 1.1 × 10(9), high reproducibility (relative standard deviation of 4.2%), and 10(-12) M rhodamine B highly sensitive detection limit by optimizing the SILAR conditions including the concentration of the reactive solution (20/20 mM/mM AgNO3/NaBH4) and the number of SILAR cycles (six). The applicability of the SERS platform was evaluated using two samples including human cervical fluid for clinical diagnosis of human papillomavirus (HPV) infection, associated with cervical cancer, and a malachite green (MG) solution for fungicide and parasiticide in aquaculture, associated with human carcinogenesis. The AgNP-immersed SERS-functionalized platform using the SILAR technique allowed for high chemical structure sensitivity without additional tagging or chemical modification, making it a good alternative for early clinical diagnosis of HPV infection and detection of MG-activated human carcinogenesis.
Cell culture and polymerase chain reaction are currently regarded as the gold standard for adenoviral conjunctivitis diagnosis. They maximize sensitivity and specificity but require several days to 3 weeks to get the results. The aim of this study is to determine the potential of Raman spectroscopy as a stand-alone analytical tool for clinical diagnosis of adenoviral conjunctivitis using human tear fluids. A drop-coating deposition surface enhanced Raman scattering (DCD-SERS) method was identified as the most effective method of proteomic analysis in tear biofluids. The proposed DCD-SERS method (using a 2-μL sample) led to Raman spectra with high reproducibility, noise-independence, and uniformity. Additionally, the spectra were independent of the volume of biofluids used and detection zones, including the ring, middle, and central zone, with the exception of the outer layer of the ring zone. Assessments with an intensity ratio of 1242-1342 cm(-1) achieved 100% sensitivity and 100% specificity in the central zone. Principal component analysis assessments achieved 0.9453 in the area under the receiver operating characteristic curve (AUC) as well as 93.3% sensitivity and 94.5% specificity in the central zone. Multi-Gaussian peak assessments showed that the differences between these two groups resulted from the reduction of the amide III α-helix structures of the proteins. The presence of adenovirus in tear fluids could be detected more accurately in the center of the sample than in the periphery. The DCD-SERS technique allowed for high chemical structure sensitivity without additional tagging or chemical modification, making it a good alternative for early clinical diagnosis of adenoviral conjunctivitis. Therefore, we are hopeful that the DCD-SERS method will be approved for use in ophthalmological clinics in the near future.
We found that bee venom acupuncture effectively protected dopaminergic neurons against 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine toxicity, possibly through inhibition of Jun activation. Our results suggest that bee venom acupuncture could be a potential preventive agent for Parkinson's disease.
Abstract:We investigate the mode of action and classification of antibiotic agents (ceftazidime, patulin, and epigallocatechin gallate; EGCG) on Pseudomonas aeruginosa (P. aeruginosa) biofilm using Raman spectroscopy with multivariate analysis, including support vector machine (SVM) and principal component analysis (PCA). This method allows for quantitative, label-free, non-invasive and rapid monitoring of biochemical changes in complex biofilm matrices with high sensitivity and specificity. In this study, the biofilms were grown and treated with various agents in the microfluidic device, and then transferred onto gold-coated substrates for Raman measurement. Here, we show changes in biochemical properties, and this technology can be used to distinguish between changes induced in P. aeruginosa biofilms using three antibiotic agents. The Raman band intensities associated with DNA and proteins were decreased, compared to control biofilms, when the biofilms were treated with antibiotics. Unlike with exposure to ceftazidime and patulin, the Raman spectrum of biofilms exposed to EGCG showed a shift in the spectral position of the CH deformation stretch band from 1313 cm −1 to 1333 cm −1 , and there was no difference in the band intensity at 1530 cm −1 (C = C stretching, carotenoids). The PCA-SVM analysis results show that antibiotic-treated biofilms can be detected with high sensitivity of 93.33%, a specificity of 100% and an accuracy of 98.33%. This method also discriminated the three antibiotic agents based on the cellular biochemical and structural changes induced by antibiotics with high sensitivity and specificity of 100%. This study suggests that Raman spectroscopy with PCA-SVM is potentially useful for the rapid identification and classification of clinically-relevant antibiotics of bacteria biofilm. Furthermore, this method could be a powerful approach for the development and screening of new antibiotics.
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