Simple spectrophotometric method for determination of polyvinylalcohol in different types of wastewater

Procházková, Lenka; Rodríguez, Yadira; Procházka, Jindřich; Wanner, J.

doi:10.1080/03067319.2013.853761

Cited by 20 publications

(6 citation statements)

References 35 publications

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“…The residual amount of PVA present on the MS in suspension was quantified indirectly, by quantifying the residual amount of PVA in the suspension of 3 mg of PLGA MS using a colorimetric method based on the formation of a colored complex between the two adjacent hydroxyl groups of PVA and an iodine molecule. 52 Briefly, the supernatants obtained during the MS washing process were collected, and 0.4 mL of the solution was mixed with 1.5 mL of boric acid solution (0.65 M) and 0.3 mL of I 2 /KI solution (0.05/0.15 M). The samples were incubated for 20 min, and the absorbance was measured at 630 nm with the SPECTROstar Nano UV−vis spectrophotometer (BMG LABTECH, Ortenberg, Germany).…”

Section: Methodsmentioning

confidence: 99%

Monosized Polymeric Microspheres Designed for Passive Lung Targeting: Biodistribution and Pharmacokinetics after Intravenous Administration

et al. 2020

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Local as well as systemic therapy is often used to treat bacterial lung infections. Delivery of antibiotics to the vascular side of infected lung tissue using lung-targeting microspheres (MS) is a good alternative to conventional administration routes, allowing for localized high levels of antibiotics. This delivery route can also complement inhaled antibiotic therapy, especially in the case of compromised lung function. We prepared and characterized monodisperse poly(lactic-co-glycolic acid) (PLGA) MS loaded with levofloxacin using a flow-focusing glass microfluidic chip. In vitro characterization showed that the encapsulated LVX displayed a biphasic controlled release during 5 days and preserved its antibacterial activity. The MS degradation was investigated in vitro by cross-sectioning the MS using a focused ion beam scanning electron microscope and in vivo by histological examination of lung tissue from mice intravenously administered with the MS. The MS showed changes in the surface morphology and internal matrix, whereas the degradation in vivo was 3 times faster than that in vitro. No effect on the viability of endothelial and lung epithelial cells or hemolytic activity was observed. To evaluate the pharmacokinetics and biodistribution of the MS, complete quantitative imaging of the 111indium-labeled PLGA MS was performed in vivo with single-photon emission computed tomography imaging over 10 days. The PLGA MS distributed homogeneously in the lung capillaries. Overall, intravenous administration of 12 μm PLGA MS is suitable for passive lung targeting and pulmonary therapy.

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Section: Methodsmentioning

confidence: 99%

Monosized Polymeric Microspheres Designed for Passive Lung Targeting: Biodistribution and Pharmacokinetics after Intravenous Administration

et al. 2020

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“…Residual PVA content in PLGA preparations was determined using an iodine–PVA spectrophotometric method as previously reported [ 14 ]. Briefly, PLGA samples (1 mg) were dissolved in 0.1 M NaOH as well as standard PVA samples ranging from 31 μg/mL up to 1 mg/mL, and were added into a 96-well plate in triplicates.…”

Section: Methodsmentioning

confidence: 99%

Adjuvantation of an Influenza Hemagglutinin Antigen with TLR4 and NOD2 Agonists Encapsulated in Poly(D,L-Lactide-Co-Glycolide) Nanoparticles Enhances Immunogenicity and Protection against Lethal Influenza Virus Infection in Mice

Tukhvatulin¹,

Dzharullaeva²,

Erokhova³

et al. 2020

Vaccines

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Along with their excellent safety profiles, subunit vaccines are typically characterized by much weaker immunogenicity and protection efficacy compared to whole-pathogen vaccines. Here, we present an approach aimed at bridging this disadvantage that is based on synergistic collaboration between pattern-recognition receptors (PRRs) belonging to different families. We prepared a model subunit vaccine formulation using an influenza hemagglutinin antigen incorporated into poly-(D,L-lactic-co-glycolic acid) (PLGA) nanoparticles adjuvanted with monophosphoryl lipid A (TLR4 agonist) and muramyl dipeptide (NOD2 agonist). The efficacy studies were conducted in comparison to control vaccine formulations containing individual PRR agonists. We show that the complex adjuvant based on TLR4 and NOD2 agonists potentiates proinflammatory cell responses (measured by activity of transcription factors and cytokine production both in vitro and in vivo) and enhances the phagocytosis of vaccine particles up to comparable levels of influenza virus uptake. Finally, mice immunized with vaccine nanoparticles containing both PRR agonists exhibited enhanced humoral (IgG, hemagglutination-inhibition antibody titers) and cellular (percentage of proliferating CD4+ T-cells, production of IFNɣ) immunity, leading to increased resistance to lethal influenza challenge. These results support the idea that complex adjuvants stimulating different PRRs may present a better alternative to individual PAMP-based adjuvants and could further narrow the gap between the efficacy of subunit versus whole-pathogen vaccines.

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“…Beads were quantified by using the green fluorescence signal (525 nm band pass filter). Loss of PVA from the hydrogel beads during incubation was quantified using a previously described blue iodine assay, modified to microwell plate 56 . In brief, each well was filled with 36.4 µL of sample, 163.3 µL of 4% boric acid solution, and 27.3 µL of iodine solution.…”

Section: Methodsmentioning

confidence: 99%

Tailoring polyvinyl alcohol-sodium alginate (PVA-SA) hydrogel beads by controlling crosslinking pH and time

Candry

Godfrey

Wang

et al. 2022

Sci Rep

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Hydrogel-encapsulated catalysts are an attractive tool for low-cost intensification of (bio)-processes. Polyvinyl alcohol-sodium alginate hydrogels crosslinked with boric acid and post-cured with sulfate (PVA-SA-BS) have been applied in bioproduction and water treatment processes, but the low pH required for crosslinking may negatively affect biocatalyst functionality. Here, we investigate how crosslinking pH (3, 4, and 5) and time (1, 2, and 8 h) affect the physicochemical, elastic, and process properties of PVA-SA-BS beads. Overall, bead properties were most affected by crosslinking pH. Beads produced at pH 3 and 4 were smaller and contained larger internal cavities, while optical coherence tomography suggested polymer cross-linking density was higher. Optical coherence elastography revealed PVA-SA-BS beads produced at pH 3 and 4 were stiffer than pH 5 beads. Dextran Blue release showed that pH 3-produced beads enabled higher diffusion rates and were more porous. Last, over a 28-day incubation, pH 3 and 4 beads lost more microspheres (as cell proxies) than beads produced at pH 5, while the latter released more polymer material. Overall, this study provides a path forward to tailor PVA-SA-BS hydrogel bead properties towards a broad range of applications, such as chemical, enzymatic, and microbially catalyzed (bio)-processes.

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Simple spectrophotometric method for determination of polyvinylalcohol in different types of wastewater

Cited by 20 publications

References 35 publications

Monosized Polymeric Microspheres Designed for Passive Lung Targeting: Biodistribution and Pharmacokinetics after Intravenous Administration

Monosized Polymeric Microspheres Designed for Passive Lung Targeting: Biodistribution and Pharmacokinetics after Intravenous Administration

Adjuvantation of an Influenza Hemagglutinin Antigen with TLR4 and NOD2 Agonists Encapsulated in Poly(D,L-Lactide-Co-Glycolide) Nanoparticles Enhances Immunogenicity and Protection against Lethal Influenza Virus Infection in Mice

Tailoring polyvinyl alcohol-sodium alginate (PVA-SA) hydrogel beads by controlling crosslinking pH and time

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