It is proposed that a whole-cell optical fiber biosensor is used as an in situ first warning detector sensor for online monitoring of environmental pollution (e.g. waste water) in remote localities. The base requirement for this sensor is a very high sensitivity topollution. The work shows a simple way to increase sensor sensitivity, optimizing the shape of an optical fiber element (OFE) for more effective coupling of the low intensity light produced by bioluminescent bioreporters.
Theoretical calculations of coupling efficiency showed that only 3.5% of photons produced by one bacterium placed on the front end of polymer-clad silica (PCS) fiber is guided to the detector. Our designed tapered OFEs with immobilized bioluminescent bioreporters Pseudomonas fluorescens HK44, with maximal transmittance, led to a sixfold increase in detected bioluminescence compared to that of the PCS fiber with the same active layer. It is shown that the shape of the OFE determines its transmission. The influences of physical properties and OFE geometry, cell immobilization into silica gel or bacterial plaque, on the intensity of detected light, were evaluated.
Dead space after rectal resection in colorectal surgery is an area with a high risk of complications. In this study, our goal was to develop a novel 3D implant based on composite hydrogels enriched with fractionalized nanofibers. We employed, as a novel approach in abdominal surgery, the application of agarose gels functionalized with fractionalized nanofibers on pieces dozens of microns large with a well-preserved nano-substructure. This retained excellent cell accommodation and proliferation, while nanofiber structures in separated islets allowed cells a free migration throughout the gel. We found these low-concentrated fractionalized nanofibers to be a good tool for structural and biomechanical optimization of the 3D hydrogel implants. In addition, this nano-structuralized system can serve as a convenient drug delivery system for a controlled release of encapsulated bioactive substances from the nanofiber core. Thus, we present novel 3D nanofiber-based gels for controlled release, with a possibility to modify both their biomechanical properties and drug release intended for 3D lesions healing after a rectal extirpation, hysterectomy, or pelvic exenteration.
In this paper, we analysed the steady state fluorescence spectra of cell suspensions containing healthy and carcinoma fibroblast mouse cells, using a genetic-algorithm-spectra-decomposition software (GASpeD). In contrast to other deconvolution algorithms, such as polynomial or linear unmixing software, GASpeD takes into account light scatter. In cell suspensions, light scatter plays an important role as it depends on the number of cells, their size, shape, and coagulation. The measured fluorescence spectra were normalized, smoothed and deconvoluted into four peaks and background. The wavelengths of intensities’ maxima of lipopigments (LR), FAD, and free/bound NAD(P)H (AF/AB) of the deconvoluted spectra matched published data. In deconvoluted spectra at pH = 7, the fluorescence intensities of the AF/AB ratio in healthy cells was always higher in comparison to carcinoma cells. In addition, the AF/AB ratio in healthy and carcinoma cells were influenced differently by changes in pH. In mixtures of healthy and carcinoma cells, AF/AB decreases when more than 13% of carcinoma cells are present. Expensive instrumentation is not required, and the software is user friendly. Due to these attributes, we hope that this study will be a first step in the development of new cancer biosensors and treatments with the use of optical fibers.
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