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The Science of the Total Environment Jan 2023Plastic food packaging represents 40 % of the plastic production worldwide and belongs to the 10 most commonly found items in aquatic environments. They are...
Plastic food packaging represents 40 % of the plastic production worldwide and belongs to the 10 most commonly found items in aquatic environments. They are characterized by high additives contents with >4000 formulations available on the market. Thus they can release their constitutive chemicals (i.e. additives) into the surrounding environment, contributing to chemical pollution in aquatic systems and to contamination of marine organism up to the point of questioning the health of the consumer. In this context, the chemical and toxicological profiles of two types of polypropylene (PP) and polylactic acid (PLA) food packaging were investigated, using in vitro bioassays and target gas chromatography mass spectrometry analyses. Plastic additives quantification was performed both on the raw materials, and on the material leachates after 5 days of lixiviation in filtered natural seawater. The results showed that all samples (raw materials and leachates) contained additive compounds (e.g. phthalates plasticizers, phosphorous flame retardants, antioxidants and UV-stabilizers). Differences in the number and concentration of additives between polymers and suppliers were also pointed out, indicating that the chemical signature cannot be generalized to a polymer and is rather product dependent. Nevertheless, no significant toxic effects was observed upon exposure to the leachates in two short-term bioassays targeting baseline toxicity (Microtox® test) and Pacific oyster Crassostrea gigas fertilization success and embryo-larval development. Overall, this study demonstrates that both petrochemical and bio-based food containers contain harmful additives and that it is not possible to predict material toxicity solely based on chemical analysis. Additionally, it highlights the complexity to assess and comprehend the additive content of plastic packaging due to the variability of their composition, suggesting that more transparency in polymer formulations is required to properly address the risk associated with such materials during their use and end of life.
Topics: Polypropylenes; Food Packaging; Water Pollutants, Chemical; Plastics; Polyesters; Polymers; Biological Assay; Risk Assessment
PubMed: 36220465
DOI: 10.1016/j.scitotenv.2022.159318 -
Environmental Research May 2023Pyrolysis oil from oil palm biomass can be a sustainable alternative to fossil fuels and the precursor for synthesizing petrochemical products due to its carbon-neutral...
Pyrolysis oil from oil palm biomass can be a sustainable alternative to fossil fuels and the precursor for synthesizing petrochemical products due to its carbon-neutral properties and low sulfur and nitrogen content. This work investigated the effect of applying mesoporous acidic catalysts, Ni-Mo/TiO and Ni/AlO in a catalytic co-pyrolysis of oil palm trunk (OPT) and polypropylene (PP) from 500 to 700 °C. The obtained oil yields varied between 12.67 and 19.50 wt.% and 12.33-17.17 wt.% for Ni-Mo/TiO and Ni/AlO, respectively. The hydrocarbon content in oil significantly increased up to 54.07-58.18% and 37.28-68.77% after adding Ni-Mo/TiO and Ni/AlO, respectively. The phenolic compounds content was substantially reduced to 8.46-20.16% for Ni-Mo/TiO and 2.93-14.56% for Ni/AlO. Minor reduction in oxygenated compounds was noticed from catalytic co-pyrolysis, though the parametric effects of temperature and catalyst type remain unclear. The enhanced deoxygenation and cracking of phenolic and oxygenated compounds and the PP decomposition resulted in increased hydrocarbon production in oil during catalytic co-pyrolysis. Catalyst addition also promoted the isomerization and oligomerization reactions, enhancing the formation of cyclic relative to aliphatic hydrocarbon.
Topics: Polypropylenes; Pyrolysis; Titanium; Hydrocarbons; Catalysis; Biomass; Biofuels; Hot Temperature
PubMed: 36841526
DOI: 10.1016/j.envres.2023.115550 -
Microbiological Research Dec 2023The urgent need for better disposal and recycling of plastics has motivated a search for microbes with the ability to degrade synthetic polymers. While microbes capable...
The urgent need for better disposal and recycling of plastics has motivated a search for microbes with the ability to degrade synthetic polymers. While microbes capable of metabolizing polyurethane and polyethylene terephthalate have been discovered and even leveraged in enzymatic recycling approaches, microbial degradation of additive-free polypropylene (PP) remains elusive. Here we report the isolation and characterization of two fungal strains with the potential to degrade pure PP. Twenty-seven fungal strains, many isolated from hydrocarbon contaminated sites, were screened for degradation of commercially used textile plastic. Of the candidate strains, two identified as Coniochaeta hoffmannii and Pleurostoma richardsiae were found to colonize the plastic fibers using scanning electron microscopy (SEM). Further experiments probing degradation of pure PP films were performed using C. hoffmannii and P. richardsiae and analyzed using SEM, Raman spectroscopy and Fourier transform infrared spectroscopy with attenuated total reflectance (FTIR-ATR). The results showed that the selected fungi were active against pure PP, with distinct differences in the bonds targeted and the degree to which each was altered. Whole genome and transcriptome sequencing was conducted for both strains and the abundance of carbohydrate active enzymes, GC content, and codon usage bias were analyzed in predicted proteomes for each. Enzymatic assays were conducted to assess each strain's ability to degrade naturally occurring compounds as well as synthetic polymers. These investigations revealed potential adaptations to hydrocarbon-rich environments and provide a foundation for further investigation of PP degrading activity in C. hoffmannii and P. richardsiae.
Topics: Plastics; Polypropylenes; Ascomycota; Fungi; Biodegradation, Environmental
PubMed: 37793281
DOI: 10.1016/j.micres.2023.127507 -
Scientific Reports Aug 2017Marine debris is widely recognized as a global environmental problem. One of its main components, microplastics, has been found in several sea salt samples from...
Marine debris is widely recognized as a global environmental problem. One of its main components, microplastics, has been found in several sea salt samples from different countries, indicating that sea products are irremediably contaminated by microplastics. Previous studies show very confusing results, reporting amounts of microparticles (MPs) in salt ranging from zero to 680 MPs/kg, with no mention of the possible causes of such differences. Several errors in the experimental procedures used were found and are reported in the present work. Likewise, 21 different samples of commercial table salt from Spain have been analyzed for MPs content and nature. The samples comprise sea salts and well salts, before and after packing. The microplastic content found was of 50-280 MPs/kg salt, being polyethylene-terephthalate (PET) the most frequently found polymer, followed by polypropylene (PP) and polyethylene (PE), with no significant differences among all the samples. The results indicate that even though the micro-particles might originate from multiple sources, there is a background presence of microplastics in the environment.
Topics: Environmental Monitoring; Food Contamination; Phthalic Acids; Plastics; Polyethylene; Polyethylene Terephthalates; Polypropylenes; Sodium Chloride, Dietary; Spain; Water Pollutants, Chemical
PubMed: 28819264
DOI: 10.1038/s41598-017-09128-x -
Journal of the American Society For... Aug 2023Sample preparation for single-cell proteomics is generally performed in a one-pot workflow with multiple dispensing and incubation steps. These hours-long processes can...
Sample preparation for single-cell proteomics is generally performed in a one-pot workflow with multiple dispensing and incubation steps. These hours-long processes can be labor intensive and lead to long sample-to-answer times. Here we report a sample preparation method that achieves cell lysis, protein denaturation, and digestion in 1 h using commercially available high-temperature-stabilized proteases with a single reagent dispensing step. Four different one-step reagent compositions were evaluated, and the mixture providing the highest proteome coverage was compared to the previously employed multistep workflow. The one-step preparation increases proteome coverage relative to the previous multistep workflow while minimizing labor input and the possibility of human error. We also compared sample recovery between previously used microfabricated glass nanowell chips and injection-molded polypropylene chips and found the polypropylene provided improved proteome coverage. Combined, the one-step sample preparation and the polypropylene substrates enabled the identification of an average of nearly 2400 proteins per cell using a standard data-dependent workflow with Orbitrap mass spectrometers. These advances greatly simplify sample preparation for single-cell proteomics and broaden accessibility with no compromise in terms of proteome coverage.
Topics: Humans; Proteome; Proteomics; Polypropylenes; Mass Spectrometry; Specimen Handling
PubMed: 37410391
DOI: 10.1021/jasms.3c00159 -
Acta Cirurgica Brasileira Jun 2015To compare the inflammatory response of three different meshes on abdominal hernia repair in an experimental model of incisional hernia. (Comparative Study)
Comparative Study
PURPOSE
To compare the inflammatory response of three different meshes on abdominal hernia repair in an experimental model of incisional hernia.
METHODS
Median fascial incision and skin synthesis was performed on 30 Wistar rats. After 21 days, abdominal hernia developed was corrected as follows: 1) No mesh; 2) Polypropylene mesh; and, 3) Ultrapro(r) mesh. After 21 days, the mesh and surrounding tissue were submitted to macroscopic (presence of adhesions, mesh retraction), microscopic analysis to identify and quantify the inflammatory and fibrotic response using a score based on a predefined scale of 0-3 degrees, evaluating infiltration of macrophages, giant cells, neutrophils and lymphocytes.
RESULTS
No significant difference was seen among groups in adherences, fibrosis, giant cells, macrophages, neutrophils or lymphocytes (p>0.05). Mesh shrinkage was observed in all groups, but also no difference was observed between polypropylene and Ultrapro mesh (7.0±9.9 vs. 7.4±10.1, respectively, p=0.967). Post-operatory complications included fistula, abscess, dehiscence, serohematic collection and reherniation, but with no difference among groups (p=0.363).
CONCLUSION
There is no difference between polypropylene (high-density) and Ultrapro(r) (low-density) meshes at 21 days after surgery in extraperitoneal use in rats, comparing inflammatory response, mesh shortening, adhesions or complications.
Topics: Animals; Dioxanes; Hernia, Ventral; Herniorrhaphy; Male; Materials Testing; Polyesters; Polypropylenes; Rats, Wistar; Reproducibility of Results; Surgical Mesh; Time Factors; Tissue Adhesions; Treatment Outcome
PubMed: 26108024
DOI: 10.1590/S0102-865020150060000001 -
Microbiological Research Feb 2023Microorganisms degrade microplastics, but their potential is still not fully exploited, e.g., due to inadequate selection of microorganisms. We developed an effective...
Microorganisms degrade microplastics, but their potential is still not fully exploited, e.g., due to inadequate selection of microorganisms. We developed an effective selection method of microorganisms capable of polyethylene (PE) and polypropylene (PP) degradation and assessed the scale of polymer degradation by microbial populations. We isolated seven bacterial strains (three Priestia megaterium strains, Klebsiella pneumoniae, Pseudomonas fluorescens, Enterobacter ludwigii, Chryseobacterium sp.) and seven fungal strains (four Fusarium spp., two Lecanicillium spp. and Trichoderma sp.) with PE degradation potential, as well as seven bacterial strains (five Serratia marcescens and two Enterobacter spp.) and six fungal strains (four Aspergillus spp., Fusarium oxysporum and Penicillium granulatum) with PP degradation ability. Scanning electron microscopy (SEM) analysis confirmed the presence of a biofilm and revealed surface changes in both PE and PP pellets, but the greatest changes (microcracks and corrugations) were observed for PP incubated with bacteria. Fourier transform infrared (FTIR) spectroscopy confirmed the structural changes on the studied polymer surfaces. In conclusion, the isolation of plastic-degrading bacteria and fungi from waste landfills represents an effective strategy for the collection of microorganisms with high potential for PE and PP degradation. The bacteria and fungi revealed better potential for PP degradation and PE degradation, respectively.
Topics: Polyethylene; Polypropylenes; Plastics; Biodegradation, Environmental; Fungi
PubMed: 36423546
DOI: 10.1016/j.micres.2022.127251 -
Acta Cirurgica Brasileira 2021To compare tissue inflammatory response, foreign body reaction, fibroplasia, and proportion of type I/III collagen between closure of abdominal wall aponeurosis using...
Analysis of tissue inflammatory response, fibroplasia, and foreign body reaction between the polyglactin suture of abdominal aponeurosis in rats and the intraperitoneal implant of polypropylene, polypropylene/polyglecaprone and polyester/porcine collagen meshes.
PURPOSE
To compare tissue inflammatory response, foreign body reaction, fibroplasia, and proportion of type I/III collagen between closure of abdominal wall aponeurosis using polyglactin suture and intraperitoneal implant of polypropylene, polypropylene/polyglecaprone, and polyester/porcine collagen meshes to repair defects in the abdominal wall of rats.
METHODS
Forty Wistar rats were placed in four groups, ten animals each, for the intraperitoneal implant of polypropylene, polypropylene/polyglecaprone, and polyester/porcine collagen meshes or suture with polyglactin (sham) after creation of defect in the abdominal wall. Twenty-one days later, histological analysis was performed after staining with hematoxylin-eosin and picrosirius red.
RESULTS
The groups with meshes had a higher inflammation score (p < 0.05) and higher number of gigantocytes (p < 0.05) than the sham group, which had a better fibroplasia with a higher proportion of type I/III collagen than the tissue separating meshes (p < 0.05). There were no statistically significant differences between the three groups with meshes.
CONCLUSIONS
The intraperitoneal implant of polypropylene/polyglecaprone and polyester/porcine collagen meshes determined a more intense tissue inflammatory response with exuberant foreign body reaction, immature fibroplasia and low tissue proportion of type I/III collagen compared to suture with polyglactin of abdominal aponeurosis. However, there were no significant differences in relation to the polypropylene mesh group.
Topics: Abdominal Wall; Animals; Aponeurosis; Collagen; Foreign-Body Reaction; Materials Testing; Polyglactin 910; Polypropylenes; Rats; Rats, Wistar; Surgical Mesh; Sutures; Swine
PubMed: 34495141
DOI: 10.1590/ACB360706 -
European Journal of Hospital Pharmacy :... Mar 2023Clonidine is an alpha-2 adrenoreceptor agonist and is frequently combined with opioids (ie, morphine hydrochloride (HCl)) for the management of chronic pain. In...
OBJECTIVES
Clonidine is an alpha-2 adrenoreceptor agonist and is frequently combined with opioids (ie, morphine hydrochloride (HCl)) for the management of chronic pain. In palliative care, the administration of clonidine and morphine HCl is recommended in case of tolerance effect. This study aimed to evaluate the physical and chemical stability of this admixture at high and low concentrations in 14 and 48 mL polypropylene syringes.
METHODS
The stability of a low concentration admixture of clonidine (Catapressan 0.15 mg/mL, Boehringer Ingelheim, Germany) and morphine (morphine HCl 40 mg/mL, Sterop, Belgium) at 0.003 and 0.417 mg/mL, respectively, was evaluated by using five polypropylene syringes of 48 mL. The high concentration admixture consisted of 0.032 mg/mL clonidine and 4.286 mg/mL morphine HCl and was evaluated by using five polypropylene syringes of 14 mL. All syringes were stored for 30 days at 5°C±3°C. Periodic samples were visually and microscopically examined to observe any particle appearance or colour change. pH and absorbance at three wavelengths (350, 410 and 550 nm) were monitored. The concentrations were measured by ultra-high performance liquid chromatography-photodiode array detection.
RESULTS
During the 30 days, there was no change in colour or appearance of opacity, turbidity or precipitation, and pH remained stable. The low and high concentration admixtures were considered chemically stable since the lower limit of the 90% CI remained superior to 90% of the initial concentration. Concentration measurements showed that the degradation rate was less than 1% over 10 days for each component in both admixtures.
CONCLUSIONS
The admixture of clonidine and morphine HCl at low and high concentrations in polypropylene syringes appeared to be physically and chemically stable throughout the study period of 30 days at 5°C±3°C. In conclusion, the admixture can be prepared in advance under aseptic conditions by a centralised intravenous additive service in the pharmacy department.
Topics: Humans; Clonidine; Polypropylenes; Syringes; Analgesics, Opioid; Morphine Derivatives; Drug Stability
PubMed: 34758972
DOI: 10.1136/ejhpharm-2021-002940 -
Acta Cirurgica Brasileira Apr 2012To evaluate the healing process of a defect in the ventral abdominal wall of rats, comparing the polypropylene and polypropylene/poliglecaprone meshes on the 30(th) and... (Comparative Study)
Comparative Study
PURPOSE
To evaluate the healing process of a defect in the ventral abdominal wall of rats, comparing the polypropylene and polypropylene/poliglecaprone meshes on the 30(th) and 60(th) postoperative day.
METHODS
Thirty two Wistar rats were submitted to a ventral abdominal wall defect, with integrity of the parietal peritoneum. In the repair, were used polypropylene (group A) and polypropylene/poliglecaprone (group B) meshes. The groups were subdivided into four subgroups of eight animals euthanized on the 30(th) (A30 and B30) and 60(th) postoperative day (A60 and B60). Fragments of the abdominal wall of the animals were submitted to macroscopic, tensiometric and histological evaluations.
RESULTS
The tensiometry on subgroup A30 showed a mean average break point of 0.78 MPa and in A60, 0.66 Mpa. In subgroup B30 it was 0.84 MPa and in B60, 1.27 Mpa. The score of the inflammatory process showed subacute phase on A30 and B30 sub-groups and chronic inflammatory process in subgroups A30 and 60B.
CONCLUSIONS
The tensile strength was higher on the wall repaired by polypropylene/poliglecaprone mesh in the 60(th) post-operative day. Histology showed higher concentration of fibrosis on the surface of the polypropylene mesh with a tendency to encapsulation. In polypropylene/poliglecaprone subgroups the histology showed higher concentration of fibrosis on the surface of mesh filaments.
Topics: Abdominal Wall; Animals; Biocompatible Materials; Dioxanes; Male; Microscopy, Electron, Scanning; Polyesters; Polypropylenes; Rats; Rats, Wistar; Surgical Mesh; Time Factors
PubMed: 22534804
DOI: 10.1590/s0102-86502012000400004