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International Journal of Molecular... Sep 2022Polymers remain an integral part of denture fabrication materials, specifically polymethylmetacrylate (PMMA). PMMA has been extensively used, particularly in... (Review)
Review
Polymers remain an integral part of denture fabrication materials, specifically polymethylmetacrylate (PMMA). PMMA has been extensively used, particularly in construction as a denture base material. Nonetheless, various challenges, including microbial threats in the form of candidiasis occurrence, still remain a biological challenge to denture wearers. The present article comprehensively reviews the biomodifications introduced to denture components, in particular denture base material, to improve the overall biological properties, together with physical, mechanical, structural integrity, and optical properties. In addition, fundamental information specifically to PMMA as a conventional denture base material and the causative aetiological microbial agents for biological threat to dentures are explored.
Topics: Denture Bases; Dentures; Materials Testing; Polymers; Polymethyl Methacrylate; Surface Properties
PubMed: 36142344
DOI: 10.3390/ijms231810426 -
NPJ Biofilms and Microbiomes Oct 2022Proteomic studies on cyanobacterial biofilms can be an effective approach to unravel metabolic pathways involved in biofilm formation and, consequently, obtain more...
Proteomic studies on cyanobacterial biofilms can be an effective approach to unravel metabolic pathways involved in biofilm formation and, consequently, obtain more efficient biofouling control strategies. Biofilm development by the filamentous cyanobacterium Toxifilum sp. LEGE 06021 was evaluated on different surfaces, glass and perspex, and at two significant shear rates for marine environments (4 s and 40 s). Higher biofilm development was observed at 4 s. Overall, about 1877 proteins were identified, and differences in proteome were more noticeable between hydrodynamic conditions than those found between surfaces. Twenty Differentially Expressed Proteins (DEPs) were found between 4 s vs. 40 s. On glass, some of these DEPs include phage tail proteins, a carotenoid protein, cyanophynase glutathione-dependent formaldehyde dehydrogenase, and the MoaD/ThiS family protein, while on perspex, DEPs include transketolase, dihydroxy-acid dehydratase, iron ABC transporter substrate-binding protein and protein NusG. This study contributes to developing a standardized protocol for proteomic analysis of filamentous cyanobacterial biofilms. This kind of proteomic analysis can also be useful for different research fields, given the broad spectrum of promising secondary metabolites and added-value compounds produced by cyanobacteria, as well as for the development of new antibiofilm strategies.
Topics: ATP-Binding Cassette Transporters; Biofilms; Carotenoids; Cyanobacteria; Glutathione; Hydro-Lyases; Hydrodynamics; Iron; Polymethyl Methacrylate; Proteome; Proteomics; Transketolase
PubMed: 36253388
DOI: 10.1038/s41522-022-00340-w -
Environmental Science and Pollution... Jun 2023In this study, the spatiotemporal distribution of microplastic deposition was investigated through ordinary Kriging interpolation, and the potential sources of...
In this study, the spatiotemporal distribution of microplastic deposition was investigated through ordinary Kriging interpolation, and the potential sources of microplastic deposition were identified by using Hybrid Single-Particle Lagrangian Integrated Trajectory model. The results showed that the total deposition flux of microplastics ranged from 79.5 to 810.0 p/(m·d). The shapes of microplastics could be divided into 4 shapes: fiber, fragment, film, and pellet. Seven polymer types of microplastics were identified, including polyamide (PA), polyethylene (PE), polyethylene terephthalate (PET), polymethyl methacrylate (PMMA), polypropylene (PP), polystyrene (PS), and polyvinyl chloride (PVC). Most microplastics were tiny and small sizes (≤ 500 μm) and colorless. Through model analysis and survey, microplastic deposition came from the study region, and the potential sources might be plastic products and wastes. The seasons with the highest and lowest total deposition flux were summer (535.5 p/(m·d)) and winter (197.5 p/(m·d)), respectively. The months of the highest and lowest total deposition flux were June 2021 (681.4 p/(m·d)) and January 2022 (112.2 p/(m·d)), respectively. Most fibers (PET, PA, PP) and fragments (PP) were distributed in populous areas such as commercial centers and residential areas. Abundant fragments (PET, PS, PE) and films (PE, PVC) were distributed around salvage stations. Almost all of the pellets (PE, PMMA) were found in the factory. Our results suggested that the temporal distribution of microplastic deposition was influenced by precipitation and mean temperature of air, and the spatial distribution of microplastic deposition was influenced by sources and population density.
Topics: Microplastics; Plastics; Polymethyl Methacrylate; Water Pollutants, Chemical; Environmental Monitoring; Polypropylenes; Polystyrenes; Polyethylene; Nylons; China; Polyethylene Terephthalates
PubMed: 37208508
DOI: 10.1007/s11356-023-27581-2 -
Nature Communications Feb 2020Bio-hybrid light-emitting diodes (Bio-HLEDs) based on color down-converting filters with fluorescent proteins (FPs) have achieved moderate efficiencies (50 lm/W) and...
Bio-hybrid light-emitting diodes (Bio-HLEDs) based on color down-converting filters with fluorescent proteins (FPs) have achieved moderate efficiencies (50 lm/W) and stabilities (300 h) due to both thermal- and photo-degradation. Here, we present a significant enhancement in efficiency (~130 lm/W) and stability (>150 days) using a zero-thermal-quenching bio-phosphor design. This is achieved shielding the FP surface with a hydrophilic polymer allowing their homogenous integration into the network of a light-guiding and hydrophobic host polymer. We rationalize how the control of the mechanical and optical features of this bio-phosphor is paramount towards highly stable and efficient Bio-HLEDs, regardless of the operation conditions. This is validated by the relationships between the stiffness of the FP-polymer phosphor and the maximum temperature reached under device operation as well as the transmittance of the filters and device efficiency.
Topics: Bioengineering; Circular Dichroism; Color; Equipment Design; Green Fluorescent Proteins; Light; Mutation; Organophosphates; Polymethyl Methacrylate; Protein Structure, Secondary; Protein Structure, Tertiary; Recombinant Proteins; Semiconductors; Temperature
PubMed: 32054851
DOI: 10.1038/s41467-020-14559-8 -
Journal of Orthopaedic Research :... Oct 2022The diagnosis of fracture nonunion following plate osteosynthesis is subjective and frequently ambiguous. Initially following osteosynthesis, loads applied to the bone...
The diagnosis of fracture nonunion following plate osteosynthesis is subjective and frequently ambiguous. Initially following osteosynthesis, loads applied to the bone are primarily transmitted through the plate. However, as callus stiffness increases, the callus is able to bear load proportional to its stiffness while forces through the plate decrease. The purpose of this study was to use a "smart" fracture plate to distinguish between phases of fracture healing by measuring forces transmitted through the plate. A wireless force sensor and small adapter were placed on the outside of a distal femoral locking plate. The adapter converts the slight bending of the plate under axial load into a transverse force which is measurable by the sensor. An osteotomy was created and then plated in the distal femur of biomechanical Sawbones. Specimens were loaded to simulate single-leg stance first with the osteotomy defect empty (acute healing), then sequentially filled with silicone (early callus) and then polymethyl methacrylate (hard callus). There was a strong correlation between applied axial load and force measured by the "smart" plate. Data demonstrate statistically significant differences between each phase of healing with as little as 150 N of axial load applied to the femur. Forces measured in the plate were significantly different between acute (100%), early callus (66.4%), and hard callus (29.5%). This study demonstrates the potential of a "smart" fracture plate to distinguish between phases of healing. These objective data may enable early diagnosis of nonunion and enhance outcomes for patients.
Topics: Biomechanical Phenomena; Bone Plates; Femoral Fractures; Fracture Fixation, Internal; Fracture Healing; Humans; Polymethyl Methacrylate; Silicones
PubMed: 34989023
DOI: 10.1002/jor.25254 -
Medicina (Kaunas, Lithuania) Jun 2022Background and Objectives: The surface condition of the materials that are used for temporary prostheses influences their microbial colonization, with a direct impact on...
Background and Objectives: The surface condition of the materials that are used for temporary prostheses influences their microbial colonization, with a direct impact on the oral tissues. This study aims at a comparative analysis of three types of resins for temporary bridges using conventional and digital technologies. The attention was focused on the analysis of the surface characteristics and mechanical strength of these materials. Materials and Methods: The surface condition was assessed for three distinct materials both before and after polishing- heat-curing resin Superpont C + B (SpofaDental, Jicin, Czech Republic) used unconventional technology, Zotion dental milling polymethyl methacrylate (PMMA) block (Zotion, Chongqing, China) for provisional crowns/bridges used in digital subtractive technologies and Freeprint Temp (Detax GmbH & Co. KG, Ettlingen, Germany) resin for temporary crowns and bridges that are used in 3D printing technologies. The two-way ANOVA analysis indicated that polishing leads to a statistically significant increase in roughness coefficients for all the three resins that were tested (p < 0.001). While the highest roughness coefficients were displayed in the 3D cured sample, the largest decrease was reported by the milled sample Results: The results revealed that surface roughness was significantly influenced by both the type of resin that was used (p < 0.001) and the treatment that was induced by finishing and polishing (p < 0.001). Similar p-values were obtained for each of the three resins. Conclusions: The results demonstrated a significant optimization of the surfaces after finishing and polishing and statistically significant differences between the surface parameters and the mechanical properties of the samples. The low values of the roughness and the acceptable values of the mechanical resistance for the conventional samples indicate these materials for the long-term temporary bridge’s realization, allowing the correct restoration of the functions and the rehabilitation at the oral level.
Topics: Composite Resins; Humans; Interdisciplinary Studies; Materials Testing; Polymethyl Methacrylate; Surface Properties
PubMed: 35744074
DOI: 10.3390/medicina58060811 -
Frontiers in Bioscience (Scholar... Jul 2022Mesial roots and isthmuses of mandibular molars are difficult areas to obtain adequate disinfection of root canal walls, and consequently microorganisms can survive... (Randomized Controlled Trial)
Randomized Controlled Trial
Mesial roots and isthmuses of mandibular molars are difficult areas to obtain adequate disinfection of root canal walls, and consequently microorganisms can survive treatment. The present study compared, through real-time polymerase chain reaction (qPCR), the effectiveness of TRUShape (TS) (Dentsply Tulsa Dental Specialties, Tulsa, OK) and Vortex Blue (VB) (Dentsply Tulsa Dental Specialties, Tulsa, OK) in removing () from the mesial canals and isthmuses of mandibular molars. Fifty extracted human lower molars were inoculated with OG1RF for 14 days, and then an initial bacterial sample was collected with paper points from mesiobuccal and mesiolingual canals and isthmuses. The specimens were randomly divided into four groups (n = 10 teeth; 20 canals each), according to instrumentation system: TS 25/0.06, TS 30/0.06, VB 25/0.06 and VB 30/0.06. The remaining 10 teeth were divided between positive control, inoculated teeth without instrumentation or irrigation, and negative controls, teeth without inoculation. After instrumentation, the final sample was taken using paper points and DNA was isolated. Primers specific for were used for qPCR. The bacterial reduction between pre- and post-instrumentation was calculated. One-way analysis of variance (ANOVA) with Bonferroni's multiple-comparisons tests were for statistical analysis with significance of ( < 0.05). All file systems were able to reduce the load of from the prepared root canals, however, TS size 30 removed significantly more bacteria than size 25. Interestingly, regardless of the size, TS files removed significantly more biofilm ( < 0.05) than did VB files (63.7% vs 50.8% for size 25, and 69.5% vs 56% for size 30). In conclusion, when combined with irrigation, TS file system is more effective than VB in reducing biofilms from mesiobuccal and mesiolingual canals and the isthmuses of mandibular molars.
Topics: Biofilms; Dental Pulp Cavity; Enterococcus faecalis; Humans; Molar; Polymethyl Methacrylate; Root Canal Preparation
PubMed: 36137981
DOI: 10.31083/j.fbs1403018 -
International Journal of Molecular... Nov 2023Polymer nanoparticles continue to be of high interest in life science applications. Still, adsorption processes occurring in protein-containing media and their...
Polymer nanoparticles continue to be of high interest in life science applications. Still, adsorption processes occurring in protein-containing media and their implications for biological responses are not generally predictable. Here, the effect of nanoparticle composition on the adsorption of bovine serum albumin (BSA), fibronectin (FN) and immunoglobulin G (IgG) as structurally and functionally different model proteins was explored by systematically altering the composition of poly(methyl methacrylate--styrene) nanoparticles with sizes in a range of about 550 nm. As determined by protein depletion from the suspension medium via a colorimetric assay, BSA and IgG adsorbed at similar quantities, while FN reached larger masses of adsorbed protein (up to 0.4 ± 0.06 µg·cm BSA, 0.42 ± 0.09 µg·cm IgG, 0.72 ± 0.04 µg·cm FN). A higher content of styrene as the more hydrophobic polymer component enhanced protein binding, which suggests a contribution of hydrophobic interactions despite the particles exhibiting strongly negatively charged surfaces with zeta potentials of -44 to -52 mV. The quantities of adsorbed proteins were estimated to correspond to a confluent surface coverage. Overall, this study illustrated how protein binding can be controlled by systematically varying the nanoparticle bulk composition and may serve as a basis for establishing interfaces with a targeted level of protein retention and/or presentation.
Topics: Styrene; Polymethyl Methacrylate; Nanoparticles; Serum Albumin, Bovine; Immunoglobulin G; Methacrylates; Adsorption; Surface Properties
PubMed: 38003579
DOI: 10.3390/ijms242216390 -
Molecules (Basel, Switzerland) Jul 2022The wetting properties of the rhamnolipid and surfactin mixtures with Triton X-165 were considered based on the contact angle measurements of their aqueous solution on...
The wetting properties of the rhamnolipid and surfactin mixtures with Triton X-165 were considered based on the contact angle measurements of their aqueous solution on the polytetrafluoroethylene (PTFE), polymethyl methacrylate (PMMA) and quartz (Q) surfaces. The obtained contact angle isotherms were described by the exponential function of the second order as well as by Szyszkowski equation in some cases. Using the contact angle isotherms of individual biosurfactants and TX165 as well as the earlier obtained isotherms of their surface tension the contact angle isotherms of the biosurfactants mixtures with TX165 were deduced. As follows the presence of the maxima on the contact angle isotherms of the biosurfactants mixtures with TX165 is justified. They do not prove negative adsorption of the biosurfactant and TX165 at the interfaces. However, the mutual exchange of the biosurfactant and TX165 molecules is observed in the layers at the interfaces. The concentration of the studied mixtures at the PTFE-solution interface was established to be close to that at the solution-air one but that at the PTFE-air is equal to zero. However, the concentration of the studied mixtures at the PMMA-solution and quartz-solution is greater than zero. The concentration at the PMMA(quartz)-air and PMMA(quartz)-solution interfaces is smaller than that at the solution-air one.
Topics: Benzene Derivatives; Glycolipids; Polyethylene Glycols; Polymethyl Methacrylate; Polytetrafluoroethylene; Quartz; Surface-Active Agents
PubMed: 35897880
DOI: 10.3390/molecules27154706 -
Journal of Orthopaedic Surgery and... Feb 2021This study aimed to prepare the polymethylmethacrylate (PMMA) bone cement release system with different concentrations of enoxaparin sodium (ES) and to investigate the...
BACKGROUND
This study aimed to prepare the polymethylmethacrylate (PMMA) bone cement release system with different concentrations of enoxaparin sodium (ES) and to investigate the release characteristics of ES after loading into the PMMA bone cement.
METHODS
In the experimental group, 40 g Palacos®R PMMA bone cement was loaded with various amount of ES 4000, 8000, 12,000, 16,000, 20,000, and 24,000 AXaIU, respectively. The control group was not loaded with ES. Scanning electron microscopy (SEM) was used to observe the surface microstructure of the bone cement in the two groups. In the experiment group, the mold was extracted continuously with pH7.4 Tris-HCL buffer for 10 days. The extract solution was collected every day and the anti-FXa potency was measured. The experiment design and statistical analysis were conducted using a quantitative response parallel line method.
RESULTS
Under the SEM, it was observed that ES was filled in the pores of PMMA bone cement polymer structure and released from the pores after extraction. There was a burst effect of the release. The release amount of ES on the first day was 0.415, 0.858, 1.110, 1.564, 1.952, and 2.513, respectively, from the six groups with various ES loading amount of 4000, 8000, 12,000, 16,000, 20,000, and 24,000 AXaIU, all reaching the peak of release on the first day. The release decreased rapidly on the next day and entered the plateau phase on the fourth day.
CONCLUSION
The prepared ES-PMMA bone cement has high application potential in orthopedic surgery. ES-PMMA bone cement shows good drug release characteristics. The released enoxaparin sodium has a local anti-coagulant effect within 24 h after application, but it will not be released for a long time, which is complementary to postoperative anti-coagulation therapy.
Topics: Anticoagulants; Bone Cements; Drug Liberation; Enoxaparin; Polymethyl Methacrylate; Porosity; Tromethamine
PubMed: 33541384
DOI: 10.1186/s13018-021-02223-w