Optical spectroscopy is increasingly used for cancer diagnostics. Tumor detection feasibility in human kidney samples using mid- and near-infrared (NIR) spectroscopy, fluorescence spectroscopy, and Raman spectroscopy has been reported (Artyushenko et al., Spectral fiber sensors for cancer diagnostics in vitro. In Proceedings of the European Conference on Biomedical Optics, Munich, Germany, 21–25 June 2015). In the present work, a simplification of the NIR spectroscopic analysis for cancer diagnostics was studied. The conventional high-resolution NIR spectroscopic method of kidney tumor diagnostics was replaced by a compact optical sensing device constructively represented by a set of four light-emitting diodes (LEDs) at selected wavelengths and one detecting photodiode. Two sensor prototypes were tested using 14 in vitro clinical samples of 7 different patients. Statistical data evaluation using principal component analysis (PCA) and partial least-squares discriminant analysis (PLS-DA) confirmed the general applicability of the LED-based sensing approach to kidney tumor detection. An additional validation of the results was performed by means of sample permutation.

Matching pairs of tumor and non-tumor kidney tissue samples of four patients were investigated ex vivo using a combination of two methods, attenuated total reflection mid infrared spectroscopy and fluorescence spectroscopy, through respectively prepared and adjusted fiber probes. In order to increase the data information content, the measurements on tissue samples in both methods were performed in the same 31 preselected positions. Multivariate data analysis revealed a synergic effect of combining the two methods for the diagnostics of kidney tumor compared to individual techniques.

Cancers of the abdominal cavity comprise one of the most prevalent forms of cancers, with the highest contribution from colon and rectal cancers (12% of the human population), followed by stomach cancers (4%). Surgery, as the preferred choice of treatment, includes the selection of adequate resection margins to avoid local recurrences due to minimal residual disease. The presence of functionally vital structures can complicate the choice of resection margins. Spectral analysis of tissue samples in combination with chemometric models constitutes a promising approach for more efficient and precise tumour margin identification. Additionally, this technique provides a real-time tumour identification approach not only for intraoperative application but also during endoscopic diagnosis of tumours in hollow organs. The combination of near-infrared and mid-infrared spectroscopy has advantages compared to individual methods for the clinical implementation of this technique as a diagnostic tool.

Quickly developing precision medicine and patient-oriented treatment strategies urgently require novel technological solutions. The randomly cell-populated scaffolds usually used for tissue engineering often fail to mimic the highly anisotropic characteristics of native tissue. In this work, an ultrasound standing-wave-based tissue engineering acoustophoretic (TEA) set-up was developed to organize murine mesenchymal stromal cells (mMSCs) in an in situ polymerizing 3-D fibrin hydrogel. The resultant constructs, consisting of 17 cell layers spaced at 300 µm, were obtained by continuous wave ultrasound applied at a 2.5 MHz frequency. The patterned mMSCs preserved the structured behavior within 10 days of culturing in osteogenic conditions. Cell viability was moderately increased 1 day after the patterning; it subdued and evened out, with the cells randomly encapsulated in hydrogels, within 21 days of culturing. Cells in the structured hydrogels exhibited enhanced expression of certain osteogenic markers, i.e., Runt-related transcription factor 2 (RUNX2), osterix (Osx) transcription factor, collagen-1 alpha1 (COL1A1), osteopontin (OPN), osteocalcin (OCN), and osteonectin (ON), as well as of certain cell-cycle-progression-associated genes, i.e., Cyclin D1, cysteine-rich angiogenic inducer 61 (CYR61), and anillin (ANLN), when cultured with osteogenic supplements and, for ANLN, also in the expansion media. Additionally, OPN expression was also augmented on day 5 in the patterned gels cultured without the osteoinductive media, suggesting the pro-osteogenic influence of the patterned cell organization. The TEA set-up proposes a novel method for non-invasively organizing cells in a 3-D environment, potentially enhancing the regenerative properties of the designed anisotropic constructs for bone healing.

Image processing methods for the registration of scattered light pictures and X-ray radiographs can improve the diagnostic yield of rheumatoid joints as compared to a separate interpretation of radiographs and optical images. The image fusion described uses thin plate spline interpolation techniques. This article also describes the image pre-processing techniques necessary to identify intrinsic landmarks that are a prerequisite for a point-based registration technique.

Zusammenfassung Die Züchtung und Gestaltung biologischen Gewebes im Labor (Tissue Engineering) verspricht breite medizinische Anwendung. Die notwendige Strukturierung der künstlichen Gewebe kann mittels stehender Ultraschallwellen durch Levitation erfolgen. In diesem Beitrag wird eine Methode zur elektrischen Detektion der Levitation und Experimente zu ihrer Verifizierung vorgestellt. Die Ultraschallwellen werden mit piezoelektrischen Wandlern erzeugt. Die Kontrolle der Levitation beruht auf der Auswertung der Sendespannung. Optische Aufnahmen levitierter Kunststoffpartikel erlaubten die frequenzabhängige Ermittlung der Levitationsebenenabstände und eine Korrelation zu den Sendespannungen. Es zeigte sich, dass die Levitationsbedingung über einen relativ breiten Frequenzbereich erfüllt ist. Durch Berücksichtigung der frequenzabhängigen Sendeleistung kann mittels einer normierten Kurve ein gleichmäßiger Schalldruck über den gesamten für die Levitation relevanten Frequenzbereich eingestellt werden. Die gewonnenen Ergebnisse fließen in die Entwicklung eines Gerätes ein, mit dem parallel mehrere Proben für das Tissue Engineering per Levitation gezielt strukturiert werden können. Die Proben werden dabei nutzerfreundlich in Silikon- oder Teflon-Kammern prozessiert, indem ein Ultraschallsender und eine Reflektorplatte verwendet werden. Damit können Versuchsreihen zum Tissue-Engineering effizienter als bisher durchgeführt werden.