Highly Aligned Bacterial Nanocellulose Films Obtained During Static Biosynthesis in a Reproducible and Straightforward Approach

Bacterial nanocellulose (BNC) is usually produced as randomly-organized highly pure cellulose nanofibers films. Its high water-holding capacity, porosity, mechanical strength, and biocompatibility make it unique. Ordered structures are found in nature and the properties appearing upon aligning polymers fibers inspire everyone to achieve highly aligned BNC (A-BNC) films. This work takes advantage of natural bacteria biosynthesis in a reproducible and straightforward approach. Bacteria confined and statically incubated biosynthesized BNC nanofibers in a single direction without entanglement. The obtained film is highly oriented within the total volume confirmed by polarization-resolved second-harmonic generation signal and Small Angle X-ray Scattering. The biosynthesis approach is improved by reusing the bacterial substrates to obtain A-BNC reproducibly and repeatedly. The suitability of A-BNC as cell carriers is confirmed by adhering to and growing fibroblasts in the substrate. Finally, the thermal conductivity is evaluated by two independent approaches, i.e., using the well-known 3 ω -method and a recently developed contactless thermoreflectance approach, confirming a thermal conductivity of 1.63 W mK −1 in the direction of the aligned fibers versus 0.3 W mK −1 perpendicularly. The fivefold increase in thermal conductivity of BNC in the alignment direction forecasts the potential of BNC-based devices outperforming some other natural polymer and synthetic materials. Bacteria confined and statically incubated for a few days biosynthesized bacterial nanocellulose (BNC) nanofibers in a single direction without entanglement. The obtained film is highly oriented within the total volume of the film, and it shows a five-fold increase in thermal conductivity in the parallel direction forecasting the potential of BNC-based devices outperforming some other natural polymer and synthetic materials

Enzymically attaching oligosaccharide-linked ‘cargoes’ to cellulose and other commercial polysaccharides via stable covalent bonds

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Predictors of complications and mortality following left colectomy with primary stapled anastomosis for cancer: results of a multicentric study with 1111 patients

Aim: Reports detailing the morbidity–mortality after left colectomy are sparse and do not allow definitive conclusions to be drawn. We aimed to identify risk factors for anastomotic leakage, perioperative mortality and complications following left colectomy for colonic malignancies. Method: We undertook a STROBE-compliant analysis of left colectomies included in a national prospective online database. Forty-two variables were analysed as potential independent risk factors for anastomotic leakage, postoperative morbidity and mortality. Variables were selected using the ‘least absolute shrinkage and selection operator’ (LASSO) method. Results: We analysed 1111 patients. Eight per cent of patients had a leakage and in 80% of them reoperation or surgical drainage was needed. A quarter of patients (24.9%) experienced at least one minor complication. Perioperative mortality was 2%, leakage being responsible for 47.6% of deaths. Obesity (OR 2.8, 95% CI 1.00–7.05, P = 0.04) and total parenteral nutrition (TPN) (OR 3.7, 95% CI 1.58–8.51, P = 0.002) were associated with increased risk of leakage, whereas female patients had a lower risk (OR 0.36, 95% CI 0.18–0.67, P = 0.002). Corticosteroids (P = 0.03) and oral anticoagulants (P = 0.01) doubled the risk of complications, which was lower with hyperlipidaemia (OR 0.3, P = 0.02). Patients on TPN had more complications (OR 4.02, 95% CI 2.03–8.07, P = 0.04) and higher mortality (OR 8.7, 95% CI 1.8–40.9, P = 0.006). Liver disease and advanced age impaired survival, corticosteroids being the strongest predictor of mortality (OR 21.5, P = 0.001). Conclusion: Requirement for TPN was associated with more leaks, complications and mortality. Leakage was presumably responsible for almost half of deaths. Hyperlipidaemia and female gender were associated with lower rates of complications. These findings warrant a better understanding of metabolic status on perioperative outcome after left colectomy