IntroductionThe subject of the experiment was bacterial nanocellulose, a natural polymer produced by bacteria – Gluconacetobacter xylinus. Following a specific modification process a cartilage-like material for restoration of damaged tissues may be produced. The obtained implants with excellent biocompatibility, mouldability, biophysical and chemical properties perfectly fit the needs of reconstructive surgery. The goal of the experiment was to develop and analyze cellulosic guidance channels in vivo for the reconstruction of damaged peripheral nerves.Material and methodsThe experiments were conducted on Wistar rats, femoral nerve. Cellulose was produced according to a self-patented method. In the experimental group tubulization was applied, whereas in the control traditional end-to-end connection was used. Observation time was 30, 60, 90, and 180 days. Results evaluation included histological analysis and postoperative observation of motor recovery.ResultsThe overgrowth of connective tissue and disorganisation of neural structures was evident in 86.67% of control specimens, while for cellulosic group it was only 35% (p = 0.0022). Tubulization prevented the excessive proliferation of connective tissue and isolated from penetration with scar tissue. Autocannibalism, being probably an evidence of neurotrophic factors amassment, was observed in cellulosic group but not in the control one. Motor recovery did not differ significantly (p > 0.05). Biocompatibility of implants was affirmed by very small level of tissue response and susceptibility to vascularisation.ConclusionsCellulosic neurotubes effectively prevent the formation of neuromas. They are of very good biocompatibility and allow the accumulation of neurotrophic factors inside, thus facilitating the process of nerve regeneration.
A series of nine tetrahydroacridine derivatives with iodobenzoic moiety were synthesized and evaluated for their cytotoxic activity against cancer cell lines-A549 (human lung adenocarcinoma), HT-29 (human colorectal adenocarcinoma) and somatic cell line-EA.hy926 (human umbilical vein cell line). All compounds displayed high cytotoxicity activity against A549 (IC 50 59.12-14.87 µM) and HT-29 (IC 50 17.32-5.90 µM) cell lines, higher than control agents-etoposide and 5-fluorouracil. Structure-activity relationship showed that the position of iodine in the substituent in the para position and longer linker most strongly enhanced the cytotoxic effect. Among derivatives, 1i turned out to be the most cytotoxic and displayed IC 50 values of 14.87 µM against A549 and 5.90 µM against HT-29 cell lines. In hyaluronidase inhibition assay, all compounds presented anti-inflammatory activity, however, slightly lower than reference compound. ADMET prediction showed that almost all compounds had good pharmacokinetic profiles. 1b, 1c and 1f compounds turned out to act against chemoresistance in cisplatin-resistant 253J B-V cells. Compounds intercalated into DNA and inhibited cell cycle in G0/G1 phase-the strongest inhibition was observed for 1i in A549 and 1c in HT-29. Among compounds, the highest apoptotic effect in both cell lines was observed after treatment with 1i. Compounds caused DNA damage and H2AX phosphorylation, which was detected in A549 and HT-29 cells. All research confirmed anticancer properties of novel tetrahydroacridine derivatives and explained a few pathways of their mechanism of cytotoxic action.
Scientific achievements enabled tremendous progress of surgical minimally invasive methods in the 20 th century. Laparoscopy and endoscopy became everyday diagnostic and therapeutic tools of modern medicine. Despite its irrefutable opportunities and advantages, classical minimally invasive surgery still has substantial limitations. These include: two-dimensional visualization without depth, a small field of view, and the necessity of precise hand-eye coordination. That is why pressure is placed on manufacturers of endoscopic devices to surmount these technical obstacles. To write this paper we searched databases for articles on new means of visualization in laparoscopic surgery. We discuss augmented reality, three-dimensional vision and image-guided surgery.
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