Although conventional white light endoscopy (WLE) is currently the gold standard for diagnosing bladder tumors, rates of false negative results and residual tumors after transurethral resection are relatively high. The goal of the present clinical study is to investigate whether using new water soluble hypericin (PVP-hypericin) as a fluorescent dye improves bladder cancer detection and diagnosis. Following instillation of PVP-hypericin (total amount of 0.25 mg hypericin bound to 25 mg polyvinylpoyrrolidone [PVP], reconstituted in 50 mL phys. sodium chloride solution), WLE and fluorescence cystoscopy (photodynamic diagnosis; PDD) were performed on patients with suspected primary or recurrent bladder malignancies (n = 57). Incubation time was 1-2 h and biopsies (n = 163) were taken from fluorescing regions and/or from regions which were suspicious under WLE. Histological investigations of the biopsies provided the final proof of malignancy (or the counterevidence). Results indicated that overall sensitivity with PVP-hypericin and PDD is significantly higher (95%) than with WLE (85%). The sensitivity of PDD in the diagnosis of carcinoma in situ (n = 12) was 100% compared with 33% for WLE. In the diagnosis of dysplasia, the sensitivity of PDD was 85% compared with 31% for WLE. PDD has a positive predictive value (PPV) of 0.75% and a negative predictive value (NPV) of 0.86%, in comparison to WLE PPV = 0.66% NPV = 0.58%. Biopsies were not taken from healthy tissues, thus specificity was markedly lower in our study (53%) than that reported in other studies (98-100%). As a conclusion, PDD using PVP-hypericin is superior to WLE in terms of sensitivity in the diagnosis of malignancies of the bladder. Results suggest that PVP-hypericin is a promising formulation for various diagnostic and therapeutic applications.

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The aim of the present study is the investigation of lipid oxidation in protein based oleogels. For this purpose, oleogels are prepared by suspension of freeze dried whey protein isolate aggregates and small amounts of water (<10%) in purified oleic rich safflower oil. The formation of conjugated dienes positively correlates with the addition of water. In contrast, a lower concentration of aldehydes is measured by headspace gas chromatography in oleogels with higher water addition, indicating a water facilitated degradation of aldehydes reacting with proteins. Determination of water activity indicates the presence of water droplets at higher water addition to oleogels. Furthermore, changes in the surface appearance (greasy‐glossy to dull) and the texture (consistent gel vs. crumbly) structure are indicative of microstructural changes due to increased water addition. The study suggests that water droplet formation is responsible for the marked increase in lipid oxidation. However, cross reaction of aldehydes with proteins is suggested to result in lowering the levels of secondary lipid oxidation products hexanal and propanal in oleogel. Practical Applications: The practical applications of the present work are related to the fabrication, processing, storage and consumption of oleogels and other protein‐lipid‐matrices. The results clearly indicate oleogels are prone to oxidation and proteins are involved by cross‐reaction resulting in visible browning during storage. Oxidation products such as hexanal (marker for secondary lipid oxidation) may not reflect the level of oxidation due to degradation by cross‐reactions with proteins. The aim of the present study is the investigation of lipid oxidation in protein based oleogels. The formation of conjugated dienes positively correlates with the addition of water. In contrast, a lower concentration of aldehydes is measured in oleogels with higher water addition. Water activity indicates the presence of water droplets at higher water addition to oleogels, which are likely responsible for the marked increase in lipid oxidation. However, cross reaction of aldehydes with proteins is suggested to result in lowering the levels of secondary lipid oxidation products hexanal and propanal in oleogels.

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