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"Infrared microscopic imaging of granulation tissue of diabetic foot ulcers healing" by Deema Jaber "The effect of Iberin against Pseudomonas aeruginosa biofilms in cystic fibrosis artificial sputum medium and on ex vivo skin explant model seminar" by Nisreen Dahshan
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Infrared microscopic imaging of granulation tissue of diabetic foot ulcers healing by D. Jaber
Diabetic patients are at high risk to develop chronic and recurrent diabetic foot infections (DFIs) because of neuropathy, vascular insufficiency, and neutrophil dysfunction. Chronic DFIs they are associated with increased frequency and length of hospitalization and risk of lower extremity amputation, so early detection will reduce and prevent future amputations. In Jordan about 5.3% of diabetic patients had foot ulcers, 1.7% had undergone amputations.
Diabetic foot wound healing process is divided into three sequential and overlapping phases: inflammation, new tissue formation (which includes re-epithelialization, granulation and angiogenesis), and remodeling
Sodium hypochlorite bactericidal action is directly related to its concentration and duration of exposure. It is fundamental to use the optimum concentration which has both adequate bactericidal capabilities as well as minimal toxicity. In vitro, it has been shown that sodium hypochlorite solution is cytotoxic to fibroblasts at concentrations of 0.025% and has a narrow margin of safety on neutrophil, fibroblast and endothelial cell viability.
Granulation tissue as any biological system is a heterogenous sample and accordingly the traditional IR spectrometer is not enough to give a representative conclusion of any changes happened to the tissue during the treatment. So we need to use Fourier transform infrared (FTIR) synchrotron as a rapid, accurate, non-destructive and cost-effective molecular method to detect and correlate changes happened to the granulation tissue. The results of FTIR will be compared with results that will be obtained from the conventional histological imaging method.
This work is a part of my PhD thesis of pharmaceutical science. In our study we will use 0.1% sodium hypochlorite, so the goal in this study is to establish a comprehensive diagnostic method using FTIR imaging of granulation tissue samples. FTIR will be used to study cytotoxicity imposed by sodium hypochlorite to the granulation tissue during the healing process of diabetic foot ulcers and infections.
The effect of Iberin against Pseudomonas aeruginosa biofilms in cystic fibrosis artificial sputum medium and on ex vivo skin explant model by N. Dahshan
Bacterial infections found in cystic fibrosis and chronic wounds share the aspect that chronicity is due to bacterial biofilms and the main player is Pseudomonas aeruginosa. Iberin is an isothiocyanate that has quorum sensing inhibitory effect and Nrf2 modulated activity on phase II detoxification enzymes. The ability of Iberin (30 - 80 µg/mL) to enhance the antibacterial activity of Tobramycin (1000 µg/mL) against Pseudomonas aeruginosa mature biofilms (48 h) was evaluated using artificial sputum medium resembling the conditions in cystic fibrosis lungs and measured as log reduction in bacterial load (CFU/ml). The results confirm the advantage of prophylactic treatment of Iberin to enhance the antibacterial activity of Tobramycin. Ex vivo skin explant model was developed to enhance the expression of bacterial virulence factors of pyocyanin and pyoverdin. This model was used to assess the effect of Iberin in combination with photodynamic antimicrobial chemotherapy (PACT) against Pseudomonas aeruginosa mature (72 h) biofilms. Iberin (60 - 80 µg/mL) enhanced the photoinactivation by Riboflavin (0.1 mg/mL) mediated PACT and 5,10,15,20-Tetrakis(1-methyl-4-pyridinio) porphyrintetra p-toluenesulfonate(TMP) (750 µg/mL) mediated PACT when it was introduced. The collateral damage exerted by the two regimens towards fibroblasts was exploited using MTT assay. Screening of subcytotoxic levels of Iberin showed that it has cytoprotective activity against Riboflavin mediated PACT while not affecting the viability of fibroblasts treated with TMP mediated PACT. Fourier transform infrared micro-spectroscopy was utilized to explore the cellular biochemical changes exerted by collateral photodamage. Multivariate analysis of the spectra using principal component analysis revealed differences in photoinduced biochemical modifications in fibroblasts between the two photodynamic regimens. Biochemical signatures of Iberin activity on fibroblasts were also explored.