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Scientific Reports Oct 2023Poly(lactic acid) (PLA) is gaining popularity in manufacturing due to environmental concerns. When comparing to poly(methyl methacrylate) (PMMA), PLA exhibits low...
Poly(lactic acid) (PLA) is gaining popularity in manufacturing due to environmental concerns. When comparing to poly(methyl methacrylate) (PMMA), PLA exhibits low melting and glass transition temperature (T). To enhance the properties of these polymers, a PMMA/PLA blend has been introduced. This study aimed to investigate the optimal ratio of PMMA/PLA blends for potential dental applications based on their mechanical properties, physical properties, and biocompatibility. The PMMA/PLA blends were manufactured by melting and mixing using twin screw extruder and prepared into thermoplastic polymer beads. The specimens of neat PMMA (M100), three different ratios of PMMA/PLA blends (M75, M50, and M25), and neat PLA (M0) were fabricated with injection molding technique. The neat polymers and polymer blends were investigated in terms of flexural properties, T, miscibility, residual monomer, water sorption, water solubility, degradation, and biocompatibility. The data was statistically analyzed. The results indicated that T of PMMA/PLA blends was increased with increasing PMMA content. PMMA/PLA blends were miscible in all composition ratios. The flexural properties of polymer blends were superior to those of neat PMMA and neat PLA. The biocompatibility was not different among different composition ratios. Additionally, the other parameters of PMMA/PLA blends were improved as the PMMA ratio decreased. Thus, the optimum ratio of PMMA/PLA blends have the potential to serve as novel sustainable biomaterial for extensive dental applications.
Topics: Polymethyl Methacrylate; Biocompatible Materials; Polyesters; Polymers; Water
PubMed: 37803035
DOI: 10.1038/s41598-023-44150-2 -
Tailoring Polymerization Controllability and Dispersity Through a Photoswitchable Catalyst Strategy.Macromolecular Rapid Communications Sep 2023Modulating on-demand polymerization is a challenge in synthetic macromolecules. Herein, tailoring polymerization controllability and dispersity during single-electron...
Modulating on-demand polymerization is a challenge in synthetic macromolecules. Herein, tailoring polymerization controllability and dispersity during single-electron transfer mediated living radical polymerization (SET-LRP) of methyl methacrylate (MMA) is achieved. Hexaarylbiimidazole (HABI) is employed as a photoswitchable catalyst, allowing reversible control of catalytic activity between an active and inactive state. In the presence of HABI and with the light on (active state), control SET-LRP of MMA follows first-order kinetics, resulting in polymers with a narrow molecular weight distribution. In contrast, polymerization responds to light and reverts to their original uncontrolled state with light off (inactive state). Therefore, repeatable resetting polymerization can be easily performed. The key to photomodulating dispersity is to use an efficient molecular switch to tailor the breadths of dispersity. Besides, the mechanism of HABI-mediated SET-LRP with switchable ability is proposed.
Topics: Polymerization; Polymers; Macromolecular Substances; Methylmethacrylate
PubMed: 37231589
DOI: 10.1002/marc.202300198 -
The Journal of Prosthetic Dentistry Nov 2023Which disinfection protocol provides optimal water contact angle and microhardness for computer-aided design and computer-aided manufacturing (CAD-CAM) polymethyl...
STATEMENT OF PROBLEM
Which disinfection protocol provides optimal water contact angle and microhardness for computer-aided design and computer-aided manufacturing (CAD-CAM) polymethyl methacrylate (PMMA) materials is unclear.
PURPOSE
The purpose of this in vitro study was to evaluate the effect of different disinfection protocols (1% sodium hypochlorite, denture cleanser gel, and effervescent tablet) on the water contact angle and microhardness of different CAD-CAM PMMA denture base materials by comparing them with a heat-polymerized PMMA.
MATERIAL AND METHODS
Disk-shaped specimens (Ø10×2 mm) were fabricated from 3 different CAD-CAM PMMAs-AvaDent (AV), Merz M-PM (M-PM), and Polident (Poli)-and a heat-polymerized PMMA (Vynacron) (CV) (n=21). Three disinfection protocols (1% sodium hypochlorite [HC], denture cleanser gel [GEL], an effervescent tablet [TAB]) were applied to simulate 180 days of cleansing. The water contact angle and microhardness of specimens were measured before and after disinfection and compared by using a 2-way ANOVA (α=.05).
RESULTS
For water contact angle, material (P=.010) and disinfection protocol (P=.002) had a significant effect. The material (P<.001), disinfection protocol (P=.001), and their interaction (P<.001) significantly affected the microhardness after disinfection. When the condition after disinfection was compared with that before disinfection, the water contact angle increased significantly in all material-disinfection protocol pairs (P≤.025), and microhardness increased significantly in all material-disinfection protocol pairs (P≤.040), except for GEL- (P=.689) or TAB-applied (P=.307) AV, HC-applied M-PM (P=.219), and TAB-applied Poli (P=.159).
CONCLUSIONS
The material and disinfection protocol affected the water contact angle of all tested PMMAs after disinfection, resulting in more hydrophobic surfaces for heat-polymerized or CAD-CAM PMMAs. The microhardness of heat-polymerized PMMA was less than that of all CAD-CAM PMMAs after disinfection, regardless of the protocol.
Topics: Polymethyl Methacrylate; Materials Testing; Denture Bases; Denture Cleansers; Disinfection; Sodium Hypochlorite; Computer-Aided Design; Surface Properties; Tablets; Water
PubMed: 35148889
DOI: 10.1016/j.prosdent.2021.12.007 -
Journal of the Mechanical Behavior of... Oct 2023Poly (methyl methacrylate) (PMMA) is a synthetic polymer commonly used for medical implants in cranioplasty and orthopedic surgery owing to its excellent mechanical...
Poly (methyl methacrylate) (PMMA) is a synthetic polymer commonly used for medical implants in cranioplasty and orthopedic surgery owing to its excellent mechanical properties, optical transparency, and minimal inflammatory responses. Recently, the development of 3D printing opens new avenues in the fabrication of patient-specific PMMA implants for personalized medicine. However, challenges are confronted when adapting medical-grade PMMA to the 3D printing process due to its dynamic viscosity and nonself-supporting characteristics before cured. In addition, the intrinsically exothermic polymerization of MMA brings about bubble generation issues that reduce its mechanical performance harshly. Therefore, in this study, an embedded 3D printing methodology followed by pressurized thermo-curing is proposed and developed: a granular alginate microgel is designed for serving as a supporting matrix when jamming formed between the granules to structurally support the extruded precursor filaments of PMMA-MMA ink during both 3D printing and post-curing; moreover, the autoclave reactor enclosing the alginate matrix and as-sculpted PMMA structures is utilized to generate temperature-dependent pressure, which serves for suppressing the bubbles and solidifying the polymerized MMA during the post-curing process. The 3D printed PMMA is comparably matchable to traditional PMMA castings in terms of their microstructures, density, thermal properties, mechanical performance and biocompatibility. In the future, the proposed embedded 3D printing platform combined with the special post-curing method has great potential for a customized and cost-effective fabrication of patient-specific, complex and functional PMMA implants.
Topics: Humans; Polymethyl Methacrylate; Polymers; Alginates; Cytoskeleton; Printing, Three-Dimensional
PubMed: 37678106
DOI: 10.1016/j.jmbbm.2023.106083 -
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 -
Journal of Biomedical Materials... Nov 2023Poly(methyl methacrylate) (PMMA) is considered an attractive substrate material for fabricating wearable skin sensors such as fitness bands and microfluidic devices....
Poly(methyl methacrylate) (PMMA) is considered an attractive substrate material for fabricating wearable skin sensors such as fitness bands and microfluidic devices. Despite its widespread use, inflammatory and allergic responses have been attributed to the use of this material. Therefore, the main objective of this study was to obtain a comprehensive understanding of potential biological effects triggered by PMMA at non-cytotoxic concentrations using in vitro models of NIH3T3 fibroblasts and reconstructed human epidermis (RhE). It was hypothesized that concentrations that do not reduce cell viability are sufficient to activate pathways of inflammatory processes in the skin. The study included cytotoxicity, cell metabolism, cytokine quantification, histopathological, and gene expression analyses. The NIH3T3 cell line was used as a testbed for screening cell toxicity levels associated with the concentration of PMMA with different molecular weights (MWs) (i.e., MW ~5,000 and ~15,000 g/mol). The lower MW of PMMA had a half-maximal inhibitory concentration (IC ) value of 5.7 mg/cm , indicating greater detrimental effects than the higher MW (IC = 14.0 mg/cm ). Non-cytotoxic concentrations of 3.0 mg/cm for MW ~15,000 g/mol and 0.9 mg/cm for MW ~5,000 g/mol) induced negative metabolic changes in NIH3T3 cells. Cell viability was severely reduced to 7% after the exposure to degradation by-products generated after thermal and photodegradation degradation of PMMA. PMMA at non-cytotoxic concentrations still induced overexpression of pro-inflammatory cytokines, chemokines, and growth factors (IL1B, CXCL10, CCL5, IL1R1, IL7, IL17A, VEGFA, FGF2, IFNG, IL15) on the RhE model. The inflammatory response was also supported by histopathological and gene expression analyses of PMMA-treated RhE, indicating tissue damage and gene overexpression. Results suggested that non-cytotoxic concentrations of PMMA (3.0 to 5.6 mg/cm for MW ~15,000 g/mol and 0.9 to 2.1 mg/cm for MW ~5,000 g/mol) were sufficient to negatively alter NIH3T3 cells metabolism and activate inflammatory events in the RhE skin.
Topics: Humans; Mice; Animals; Polymethyl Methacrylate; NIH 3T3 Cells; Skin; Epidermis; Epidermal Cells; Cytokines
PubMed: 37589190
DOI: 10.1002/jbm.a.37591 -
Scientific Reports Jul 2023All types of cranioplasty techniques restore the morphology of the skull and affect patient aesthetics. Safe and easy techniques are required to enhance patients'...
All types of cranioplasty techniques restore the morphology of the skull and affect patient aesthetics. Safe and easy techniques are required to enhance patients' recovery and the rehabilitation process. We propose a new method of cranioplasty. The 3-dimensional (3D) reconstruction of a thin-layer computed tomography (CT) scan of the skull was used to reflect the intact side onto the defect and subtract the overlapping points from one another. In this way, a 3D model of the planned implant can be built in the required shape and size. The precise fit of the implant can be checked by printing the defective part of the skull in case it can be modified. A sterilisable silicone mould based on the finalized model was created afterwards. Polymethyl methacrylate implants were prepared directly in an aseptic environment in the operating room during surgery. Between 2005 and 2020, we performed 54 cranioplasties on 52 patients whose craniotomies were performed previously for indications of traumatic brain injury, stroke or tumour surgeries. No technical problems were noted during the operations. In 2 cases, septic complications that occurred were not connected to the technique itself, and the implants were removed and later replaced. Our proposed technique based on 3D-printed individual silicone moulds is a reliable, safe, easily reproducible and low-cost method to repair different skull defects.
Topics: Humans; Polymethyl Methacrylate; Silicones; Plastic Surgery Procedures; Skull; Prostheses and Implants; Printing, Three-Dimensional
PubMed: 37491550
DOI: 10.1038/s41598-023-38772-9 -
International Journal of Biological... Dec 2023In order to reduce the harmful effects of synthetic non-biodegradable hydrogel, biopolymers have attracted attention, particularly for use in slow-release fertilizers....
Preparation and characterization of slow-release fertilizers loaded guar gum-g-poly methylmethacrylate-cl-polylactic acid (Gg-g-PMMA-cl-PLA) hydrogel and its effect on wheat growth.
In order to reduce the harmful effects of synthetic non-biodegradable hydrogel, biopolymers have attracted attention, particularly for use in slow-release fertilizers. The current attempt intends to develop a hydrogel from biopolymers for sustainable release of water and nutrients in soil. Here, guar gum is used as a polysaccharide, MMA as a monomer, KPS as an initiator, and Polylactic acid as a cross-linker. Further investigation is done to study synthesized hydrogel in the development of wheat crop. Biodegradation study shows that it's environmentally favorable and degradable, contributing nutrients to the soil as it decomposes. Fertilizer release studies in soil and water show that the timing of the nutrient release is delayed, improving soil water holding capacity and retention studies. The agronomic parameters show that fertilizers-loaded hydrogel has a positive effect on physiological, morphological characteristics like shoot length, root length, number of shoots and roots, shoot weight and root weight, chlorophyll content, and most notably, fruiting efficiency is enhanced as compared with commercially available hydrogel. ATR-FTIR, SEM-EDX, TGA-DTA, and XRD analysis used to confirm successful loading of fertilizers and biodegradation of hydrogel. The encouraging findings suggested that this hydrogel could be used as a multifunctional, fertilizers-loaded hydrogel in crop production.
Topics: Hydrogels; Fertilizers; Triticum; Soil; Polyesters; Water; Biopolymers; Methylmethacrylates
PubMed: 37739290
DOI: 10.1016/j.ijbiomac.2023.126979 -
PloS One 2023This study aims to observe the accelerated aging effect of 60Co gamma (γ) irradiation on poly (methyl methacrylate) (PMMA) under extreme conditions and determine the...
This study aims to observe the accelerated aging effect of 60Co gamma (γ) irradiation on poly (methyl methacrylate) (PMMA) under extreme conditions and determine the influence of different media states on aging. PMMA samples were prepared at room temperature under varying media conditions, including air and deionized water immersion. Then, the samples were irradiated with different doses (50, 250, 500, and 1000 KGy) of 60Co γ-rays. The compositional changes of the PMMA samples exposed to the rays at different periods were determined via Fourier transform infrared spectroscopy. The light transmission of the samples was characterized through ultraviolet-visible spectrophotometry, and the surface wettability of the samples was assessed via water contact angle measurements. Surface and microscopic changes in material morphology were analyzed using optical microscopy, ImageJ software, and scanning electron microscopy. Relative molecular mass and glass transition temperature were analyzed via gel permeation chromatography and differential scanning calorimetry. Thus, a comprehensive analysis of the effect of 60Co γ irradiation on the aging properties of PMMA was performed.
Topics: Polymethyl Methacrylate; Cobalt Radioisotopes; Biocompatible Materials; Microscopy, Electron, Scanning
PubMed: 37713447
DOI: 10.1371/journal.pone.0291344 -
Nanomedicine (London, England) May 2024To investigate whether medical devices coated with a synthesized nanocomposite of poly(methylmethacrylate-co-dimethyl acrylamide) (PMMDMA) and silver nanoparticles...
To investigate whether medical devices coated with a synthesized nanocomposite of poly(methylmethacrylate-co-dimethyl acrylamide) (PMMDMA) and silver nanoparticles (AgNPs) could improve their antibiofilm and antimicrobial activities. We also investigated the nanocomposite's safety. The nanocomposite was synthesized and characterized using analytical techniques. Medical devices coated with the nanocomposite were evaluated for bacterial adhesion and hemolytic activity . The nanocomposite formation was demonstrated with the incorporation of AgNPs into the polymer matrix. The nanocomposite proved to be nonhemolytic and significantly inhibited bacterial biofilm formation. The PMMDMA-AgNPs nanocomposite was more effective in preventing biofilm formation than PMMDMA alone and is a promising strategy for coating medical devices and reducing mortality due to hospital-acquired infections.
PubMed: 38722243
DOI: 10.1080/17435889.2024.2345044