Browsing by Author "Nickelsen, J."

Now showing 1 - 3 of 3
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    In vitro and in vivo detection of microbial gene expression in bioactivated scaffolds seeded with cyanobacteria
    (WILEY, 2022) Leibrock, L. B.; Hofmann, D. M.; Fuchs, B.; Birt, A.; Reinholz, M.; Guertler, A.; Frank, K.; Giunta, R. E.; Egaña Erazo Jose Tomas; Nickelsen, J.; Schenck, T. L.; Moellhoff, N.
    Dermal replacement materials bioactivated with cyanobacteria have shown promising potential for wound regeneration. To date, extraction of cyanobacteria RNA from seeded scaffolds has not been described. The aim of this study was to develop a method to isolate total RNA from bioactivated scaffolds and to propose a new approach in determining living bacteria based on real-time PCR. Transgenic Synechococcus sp. PCC 7002 (tSyn7002) were seeded in liquid cultures or scaffolds for dermal regeneration in vitro and in vivo for 7 days. RNA was extracted with a 260/280 ratio of >= 2. The small subunit of the 30S ribosome in prokaryotes (16S) and RNAse P protein (rnpA) were validated as reference transcripts for PCR analysis. Gene expression patterns differed in vitro and in vivo. Expression of 16S was significantly upregulated in scaffolds in vitro, as compared to liquid cultures, whilst rnpA expression was comparable. In vivo, both 16S and rnpA showed reduced expression compared to in vitro (16S: in vivo Ct value 13.21 +/- 0.32, in vitro 12.44 +/- 0.42; rnpA in vivo Ct value 19.87 +/- 0.41, in vitro 17.75 +/- 1.41). Overall, the results demonstrate rnpA and 16S expression after 7 days of implantation in vitro and in vivo, proving the presence of living bacteria embedded in scaffolds using qPCR.
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    Photosymbiosis for Biomedical Applications.
    (2020) Chávez, Myra N.; Moellhoff, Nichola; Schenck, T.; Egaña, José Tomás; Nickelsen, J.
    Without the sustained provision of adequate levels of oxygen by the cardiovascular system, the tissues of higher animals are incapable of maintaining normal metabolic activity, and hence cannot survive. The consequence of this evolutionarily suboptimal design is that humans are dependent on cardiovascular perfusion, and therefore highly susceptible to alterations in its normal function. However, hope may be at hand. “Photosynthetic strategies,” based on the recognition that photosynthesis is the source of all oxygen, offer a revolutionary and promising solution to pathologies related to tissue hypoxia. These approaches, which have been under development over the past 20 years, seek to harness photosynthetic microorganisms as a local and controllable source of oxygen to circumvent the need for blood perfusion to sustain tissue survival. To date, their applications extend from the in vitro creation of artificial human tissues to the photosynthetic maintenance of oxygen-deprived organs both in vivo and ex vivo, while their potential use in other medical approaches has just begun to be explored. This review provides an overview of the state of the art of photosynthetic technologies and its innovative applications, as well as an expert assessment of the major challenges and how they can be addressed.
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    Towards autotrophic tissue engineering : Photosynthetic gene therapy for regeneration
    (2016) Chavez, M.; Schenck, T.; Hopfner, U.; Centeno, C.; Somlai, I.; Schwarz, C.; Machens, H.; Heikenwalder, M.; Bono, M.; Egaña, José T.; Allende, M.; Nickelsen, J.