Pectin nanocoating reduces proinflammatory fibroblast response to bacteria.

Implant failures are primarily related to bacterial infections and inflammation. Nanocoating of implant devices with organic molecules is a method used for improving their integration into host tissues and limiting inflammation. Bioengineered plant-derived rhamnogalacturonan-Is (RG-Is) from pectins improve tissue regeneration and exhibit anti-inflammatory properties. Therefore, the aim of this study is to evaluate the in vitro effect of RG-I nanocoating on human gingival primary fibroblast (HGF) activity and proinflammatory response following Porphyromonas gingivalis (P. gingivalis) infection. Infected HGFs were incubated on tissue culture polystyrene (TCPS) plates coated with unmodified RG-I isolated from potato pectin (PU) and dearabinanated RG-I (PA). HGF morphology, proliferation, metabolic activity, and expression of genes responsible for extracellular matrix (ECM) turnover and proinflammatory response were examined. Following the P. gingivalis infection, PU and PA significantly promoted HGF proliferation and metabolic activity. Moreover, gene expression levels of IL1B, IL8, TNFA, and MMP2 decreased in the infected cells cultured on PU and PA, whereas the expression of COL1A1, FN1, and FGFR1 was upregulated. The results indicate that RG-Is are promising candidates for nanocoating of an implant surface, can reduce inflammation, and enhance implant integration, particularly in medically compromised patients with chronic inflammatory diseases such as periodontitis and rheumatoid arthritis. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 3475-3481, 2017.

Nanocoating with plant-derived pectins activates osteoblast response in vitro.

A new strategy to improve osseointegration of implants is to stimulate adhesion of bone cells, bone matrix formation, and mineralization at the implant surface by modifying surface coating on the nanoscale level. Plant-derived pectins have been proposed as potential candidates for surface nanocoating of orthopedic and dental titanium implants due to 1) their osteogenic stimulation of osteoblasts to mineralize and 2) their ability to control pectin structural changes. The aim of this study was to evaluate in vitro the impact of the nanoscale plant-derived pectin Rhamnogalacturonan-I (RG-I) from potato on the osteogenic response of murine osteoblasts. RG-I from potato pulps was isolated, structurally modified, or left unmodified. Tissue culture plates were either coated with modified RG-I or unmodified RG-I or - as a control - left uncoated. The effect of nanocoating on mice osteoblast-like cells MC3T3-E1 and primary murine osteoblast with regard to proliferation, osteogenic response in terms of mineralization, and gene expression of Runt-related transcription factor 2 (Runx2), alkaline phosphate (Alpl), osteocalcin (Bglap), α-1 type I collagen (Col1a1), and receptor activator of NF-κB ligand (Rankl) were analyzed after 3, 7, 14, and 21 days, respectively. Nanocoating with pectin RG-Is increased proliferation and mineralization of MC3T3-E1 and primary osteoblast as compared to osteoblasts cultured without nanocoating. Moreover, osteogenic transcriptional response of osteoblasts was induced by nanocoating in terms of gene induction of Runx2, Alpl, Bglap, and Col1a1 in a time-dependent manner - of note - to the highest extent under the PA-coating condition. In contrast, Rankl expression was initially reduced by nanocoating in MC3T3-E1 or remained unaltered in primary osteoblast as compared to the uncoated controls. Our results showed that nanocoating of implants with modified RG-I beneficially 1) supports osteogenesis, 2) has the capacity to improve osseointegration of implants, and is therefore 3) a potential candidate for nanocoating of bone implants.

Nonylphenols degradation in the UV, UV/H2O2, O3and UV/O3processes - comparison of the methods and kinetic study.

This paper describes the results of experiments on the decomposition of selected nonylphenols (NPs) in aqueous solutions using the UV, UV/H2O2, O3and UV/O3processes. The goal of the research was to determine the kinetic parameters of the above-mentioned processes, and to estimate their effectiveness. These substances were selected because of their ubiquitous occurrence in the aquatic environment, resistance to biodegradation and environmental significance. As a result of the experiments, the quantum yields of the 4-n-nonylphenol (4NP) and NP (technical mixture) photodegradation in aqueous solution were calculated to be 0.15 and 0.17, respectively. The values of the second-order rate constants of the investigated compounds with hydroxyl radical and NP with ozone were also determined. The estimated second-order rate constants of 4NP and NP with hydroxyl radicals were equal to 7.6 × 108-1.3 × 109 mol⁻¹ L s⁻¹. For NP, the determined rate constant with ozone was equal to 2.01 × 106 mol⁻¹ L s⁻¹. The performed experiments showed that NP was slightly more susceptible to degradation by the UV radiation and hydroxyl radicals than 4NP. The study demonstrated also that the polychromatic UV-light alone and also in combination with selected oxidizers (i.e. hydrogen peroxide, ozone) may be successfully used for the removal of selected NPs from the aqueous medium.

Comparison of ammonia-oxidizing bacterial community structure in membrane-assisted bioreactors using PCR-DGGE and FISH.

The ammonia-oxidizing bacterial (AOB) communities in three membrane bioreactors (MBRs) were monitored for 2 months after an acclimation period in order to investigate the influence of sludge age and medium type on AOB changeability and its connection with nitrification effectiveness. One MBR with a sludge age of 4 days was fed with a synthetic medium, whereas the other two with sludge ages of 8 and 32 days were fed with landfill leachate. The research revealed that landfill leachate can be effectively treated in an MBR with a higher sludge age for longer periods of time and that this improvement in performance was correlated with an increase in AOB biodiversity. Interestingly, the medium type has a stronger influence on AOB biocenosis formation than the sludge age.

Photochemical degradation of naproxen in the aquatic environment.

Naproxen belongs to the group of non-steroidal anti-inflammatory drugs. It is often used to treat pain of rheumatic and non-rheumatic diseases. The photochemical experiments of naproxen degradation were performed in the wastewater effluents from wastewater treatment plant (WWTP) Kloten/Switzerland at its real concentrations (without standard addition) and in drinking water containing naproxen standard, adjusted to pH = 7 and pH = 6. All performed experiments showed that within 5 min of photochemical oxidation, the disappearance of naproxen exceeded 90%. The first-order rate constants of naproxen degradation were determined. The maximal value of rate constant was observed by UV/H2O2 process in water samples at pH = 6 (k = 0.997 min(-1)).

Leachate detoxification by combination of biological and TiO2-photocatalytic processes.

Landfill leachates are a problematic wastewater due to their variable concentration, volume changing in time and presence of refractory and hazardous components. In this paper, the results of a new approach to photocatalysis assisted by biological process for the detoxification of stabilised landfill leachate are presented. The biologically pre-treated leachate still contained a significant amount of non-biodegradable COD and TOC amounting to 500 and 200 mg/L, respectively. The 300 min of photocatalytic treatment (UVC/TiO2) brought about a significant decrease in more than 80% refractory organics remaining in leachate. The effect of pH and catalyst loading on mineralisation, colour removal rate and biodegradability (BOD/COD) improvement in the photoreactor were discussed. The bio-accessibility of formed photocatalytic oxidation intermediates was confirmed by oxygen uptake rate (OUR) measurements. Consequently, a part of COD was successfully removed in post-biological treatment.

Nitrification of ammonia nitrogen high concentration in membrane assisted bioreactor.

Use of the membrane-assisted bioreactors (MBR) in wastewater treatment can bring a lot of advantages. Usually COD removal achieves level 90% and nitrification of ammonia nitrogen concentrations typical for municipal wastewater performs without any disturbances, what was confirmed by large number of experiments. However, inhibition of nitrification of the high ammonia nitrogen concentration was noticed. In this study, the performance of ammonia-rich wastewater nitrification in membrane-assisted bioreactor (MBR) was examined. With SRT of 40, 32, 24 and 16 days any nitrification inhibition effect wasn't noticed. Ammonia nitrogen removal was around 98% and full nitrification was observed. At the sludge age equal to 12 d the first stage of nitrification was full, but the second stage of nitrification was incomplete. The variation in number and presence of the higher organisms were noticed at the all examined sludge ages. With SRT of 40, 32, 24 and 16 days the free ciliates were prominent organisms. At the sludge age of 12 days the domination of flagellates was observed The kinetic constants of the high-ammonia wastewater nitrification were calculated The average value of Vmax at the sludge age 12, 16 and 24 days was constant (4.7 mg NH4(+)-N/g MLSS h, 4.8 mg NH4(+)-N/g MLSS h and 4.8 mg NH4(+)-N/g MLSS, respectively), but the value of Km rose, when the sludge age increased (6.8 mg NH4(+)-N/L for 12 days, 11.3 mg NH4(+)-N/L for 16 days, 21.6 mg NH4(+)-N/L for 24 days). At the sludge age 32 and 40 days the increase of Vmax was observed (7.2 mg NH4(+)-N/g MLSS h and 12.5 mg NH4(+)-N/g MLSS h, respectively) and, also, changes of Km (6.8 mg NH4(+)-N/L and 44 mg NH4(+)-N/L, respectively. Concerning the second stage of nitrification value of Vmax decreased with the increase of the sludge age and the average Km varied from 20.3 to 31.3 mg NO2(-)-N/L.