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1.
J Environ Manage ; 365: 121638, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38959766

RESUMO

In the sludge dewatering process, a formidable challenge arises due to the robust interactions between extracellular polymeric substances (EPS) and bound water. This study introduces a novel, synergistic conditioning method that combines iron (Fe2+)/peroxymonosulfate (PMS) and polyacrylamide (PAM) to significantly enhance sludge dewatering efficiency. The application of the Fe2+/PMS-PAM conditioning method led to a substantial reduction in specific filtration resistance (SFR) by 82.75% and capillary suction time (CST) by 80.44%, marking a considerable improvement in dewatering performance. Comprehensive analyses revealed that pre-oxidation with Fe2+/PMS in the Fe2+/PMS-PAM process effectively degraded EPS, facilitating the release of bound water. Subsequently, PAM enhanced the flocculation of fine sludge particles resulting from the advanced oxidation processes (AOPs). Furthermore, analysis based on the Extended Derjaguin-Landau-Verwey-Overbeek (XDLVO) theory demonstrated shifts in interaction energies, highlighting the breakdown of energy barriers within the sludge and a transition in surface characteristics from hydrophilic (3.79 mJ m-2) to hydrophobic (-61.86 mJ m-2). This shift promoted the spontaneous aggregation of sludge particles. The innovative use of the Flory-Huggins theory provided insights into the sludge filtration mechanism from a chemical potential perspective, linking these changes to SFR. The introduction of Fe2+/PMS-PAM conditioning disrupted the uniformity of the EPS-formed gel layer, significantly reducing the chemical potential difference between the permeate and the water in the gel layer, leading to a lower SFR and enhanced dewatering performance. This thermodynamic approach significantly enhances our understanding of sludge dewatering and conditioning. These findings represent a paradigm shift, offering innovative strategies for sludge treatment and expanding our comprehension of dewatering and conditioning techniques.


Assuntos
Resinas Acrílicas , Ferro , Esgotos , Eliminação de Resíduos Líquidos , Esgotos/química , Ferro/química , Resinas Acrílicas/química , Eliminação de Resíduos Líquidos/métodos , Floculação , Peróxidos/química , Oxirredução , Filtração
2.
AAPS PharmSciTech ; 25(6): 162, 2024 Jul 12.
Artigo em Inglês | MEDLINE | ID: mdl-38997615

RESUMO

In 1987, Won invented the solid-phase porous microsphere (MS), which stores bioactive compounds in many interconnected voids. Spherical particles (5-300 µm), MS, may form clusters of smaller spheres, resulting in many benefits. The current investigation focussed on gel-encased formulation, which can be suitable for dermal usage. First, quasi-emulsion (w/o/w) solvent evaporation was used to prepare 5-fluorouracil (5 FU) MS particles. The final product was characterized (SEM shows porous structure, FTIR and DSC showed drug compatibility with excipients, and gel formulation is shear-thinning) and further scaled up using the 8-fold method. Furthermore, CCD (Central Composite Design) was implemented to obtain the optimized results. After optimizing the conditions, including the polymer (600 mg, ethyl cellulose (EC), eudragit RS 100 (ERS)), stirring speed (1197 rpm), and surfactant concentration (2% w/v), we achieved the following results: optimal yield (63%), mean particle size (152 µm), drug entrapment efficiency (76%), and cumulative drug release (74.24% within 8 h). These findings are promising for industrial applications and align with the objectives outlined in UN Sustainable Development Goals 3, 9, and 17, as well as the goals of the G20 initiative.


Assuntos
Sistemas de Liberação de Medicamentos , Liberação Controlada de Fármacos , Fluoruracila , Microesferas , Tamanho da Partícula , Fluoruracila/administração & dosagem , Fluoruracila/química , Sistemas de Liberação de Medicamentos/métodos , Porosidade , Emulsões/química , Celulose/química , Celulose/análogos & derivados , Química Farmacêutica/métodos , Polímeros/química , Excipientes/química , Solventes/química , Tensoativos/química , Resinas Acrílicas/química , Portadores de Fármacos/química , Géis/química
3.
Sci Rep ; 14(1): 15695, 2024 Jul 08.
Artigo em Inglês | MEDLINE | ID: mdl-38977824

RESUMO

Hydrogels are extensively explored as biomaterials for tissue scaffolds, and their controlled fabrication has been the subject of wide investigation. However, the tedious mechanical property adjusting process through formula control hindered their application for diverse tissue scaffolds. To overcome this limitation, we proposed a two-step process to realize simple adjustment of mechanical modulus over a broad range, by combining digital light processing (DLP) and post-processing steps. UV-curable hydrogels (polyacrylamide-alginate) are 3D printed via DLP, with the ability to create complex 3D patterns. Subsequent post-processing with Fe3+ ions bath induces secondary crosslinking of hydrogel scaffolds, tuning the modulus as required through soaking in solutions with different Fe3+ concentrations. This innovative two-step process offers high-precision (10 µm) and broad modulus adjusting capability (15.8-345 kPa), covering a broad range of tissues in the human body. As a practical demonstration, hydrogel scaffolds with tissue-mimicking patterns were printed for cultivating cardiac tissue and vascular scaffolds, which can effectively support tissue growth and induce tissue morphologies.


Assuntos
Hidrogéis , Impressão Tridimensional , Engenharia Tecidual , Alicerces Teciduais , Alicerces Teciduais/química , Hidrogéis/química , Engenharia Tecidual/métodos , Humanos , Alginatos/química , Materiais Biocompatíveis/química , Resinas Acrílicas/química , Módulo de Elasticidade , Luz
4.
BMC Oral Health ; 24(1): 775, 2024 Jul 10.
Artigo em Inglês | MEDLINE | ID: mdl-38987748

RESUMO

Acrylic resins are widely used as the main components in removable orthodontic appliances. However, poor oral hygiene and maintenance of orthodontic appliances provide a suitable environment for the growth of pathogenic microorganisms. In this study, strontium-modified phosphate-based glass (Sr-PBG) was added to orthodontic acrylic resin at 0% (control), 3.75%, 7.5%, and 15% by weight to evaluate the surface and physicochemical properties of the novel material and its in vitro antifungal effect against Candida albicans (C. albicans). Surface microhardness and contact angle did not vary between the control and 3.75% Sr-PBG groups (p > 0.05), and the flexural strength was lower in the experimental groups than in the control group (p < 0.05), but no difference was found with Sr-PBG content (p > 0.05). All experimental groups showed an antifungal effect at 24 and 48 h compared to that in the control group (p < 0.05). This study demonstrated that 3.75% Sr-PBG exhibits antifungal effects against C. albicans along with suitable physicochemical properties, which may help to minimize the risk of adverse effects associated with harmful microbial living on removable orthodontic appliances and promote the use of various materials.


Assuntos
Resinas Acrílicas , Antifúngicos , Candida albicans , Vidro , Teste de Materiais , Fosfatos , Estrôncio , Propriedades de Superfície , Candida albicans/efeitos dos fármacos , Resinas Acrílicas/química , Estrôncio/farmacologia , Estrôncio/química , Antifúngicos/farmacologia , Vidro/química , Fosfatos/farmacologia , Polimerização , Dureza , Resistência à Flexão , Humanos , Técnicas In Vitro
5.
ACS Nano ; 18(28): 18211-18229, 2024 Jul 16.
Artigo em Inglês | MEDLINE | ID: mdl-38946122

RESUMO

Transarterial chemoembolization (TACE), the mainstay treatment of unresectable primary liver cancer that primarily employs nondegradable drug-loaded embolic agents to achieve synergistic vascular embolization and locoregional chemotherapy effects, suffers from an inferior drug burst behavior lacking long-term drug release controllability that severely limits the TACE efficacy. Here we developed gelatin-based drug-eluting microembolics grafted with nanosized poly(acrylic acid) serving as a biodegradable ion-exchange platform that leverages a counterion condensation effect to achieve high-efficiency electrostatic drug loading with electropositive drugs such as doxorubicin (i.e., drug loading capacity >34 mg/mL, encapsulation efficiency >98%, and loading time <10 min) and an enzymatic surface-erosion degradation pattern (∼2 months) to offer sustained locoregional pharmacokinetics with long-lasting deep-tumor retention capability for TACE treatment. The microembolics demonstrated facile microcatheter deliverability in a healthy porcine liver embolization model, superior tumor-killing capacity in a rabbit VX2 liver cancer embolization model, and stabilized extravascular drug penetration depth (>3 mm for 3 months) in a rabbit ear embolization model. Importantly, the microembolics finally exhibited vessel remodeling-induced permanent embolization with minimal inflammation responses after complete degradation. Such a biodegradable ion-exchange drug carrier provides an effective and versatile strategy for enhancing long-term therapeutic responses of various local chemotherapy treatments.


Assuntos
Quimioembolização Terapêutica , Doxorrubicina , Animais , Quimioembolização Terapêutica/métodos , Doxorrubicina/química , Doxorrubicina/farmacologia , Doxorrubicina/administração & dosagem , Doxorrubicina/farmacocinética , Coelhos , Neoplasias Hepáticas/terapia , Neoplasias Hepáticas/patologia , Neoplasias Hepáticas/tratamento farmacológico , Suínos , Resinas Acrílicas/química , Polieletrólitos/química , Portadores de Fármacos/química , Antibióticos Antineoplásicos/administração & dosagem , Antibióticos Antineoplásicos/química , Antibióticos Antineoplásicos/farmacologia , Antibióticos Antineoplásicos/farmacocinética , Gelatina/química , Nanopartículas/química , Humanos , Liberação Controlada de Fármacos , Antineoplásicos/química , Antineoplásicos/farmacologia , Antineoplásicos/administração & dosagem
6.
AAPS PharmSciTech ; 25(6): 166, 2024 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-39009861

RESUMO

Cancer has been an enormous pain point for patients and regulatory bodies across the globe. In Dec. 2023, the US FDA released guidance on benzene-grade carbomer formulations, which triggered pharmaceutical manufacturers to assess risk, test finished products, and reformulate drug products with benzene-grade carbomer. The immediate implementation of the stoppage of finished products with benzene-grade carbomers has threatened pharmaceutical excipients and finished product manufacturers. The gravity of this situation prompted the US Pharmacopeia to extend the deadline for discontinuation from August 1, 2025, to August 1, 2026, allowing manufacturers ample time for reformulation and regulatory compliance.There is an immediate need to understand the guidance and to learn how manufacturers should do the risk assessment and approach reformulation. This review provides an in-depth analysis of the risk assessment and reformulation processes involved in various dosage forms utilizing benzene-grade carbomer, supported by specific case studies.This review offers insights into navigating the USFDA guidelines to ensure formulation safety and compliance, thus enabling pharmaceutical practitioners to uphold the highest standards of patient care and tackle life cycle management challenges.The decision of the USFDA to restrict the usage of high benzene content of carbomer in the formulation is a welcome move. This article has shown a way for researchers to see opportunities in the path and provide best-in-class medicines to patients with a better formulation safety profile.


Assuntos
Benzeno , United States Food and Drug Administration , Medição de Risco/métodos , Estados Unidos , Benzeno/química , United States Food and Drug Administration/normas , Humanos , Química Farmacêutica/métodos , Excipientes/química , Composição de Medicamentos/métodos , Indústria Farmacêutica/métodos , Indústria Farmacêutica/normas , Resinas Acrílicas/química
7.
Environ Geochem Health ; 46(9): 329, 2024 Jul 16.
Artigo em Inglês | MEDLINE | ID: mdl-39012551

RESUMO

Tailings dust can negatively affect the surrounding environment and communities because the tailings are vulnerable to wind erosion. In this study, the effects of halides (sodium chloride [NaCl], calcium chloride [CaCl2], and magnesium chloride hexahydrate [MgCl2·6H2O]), and polymer materials (polyacrylamide [PAM], polyvinyl alcohol [PVA], and calcium lignosulfonate [LS]) were investigated for the stabilization of tailings for dust control. Erect milkvetch (Astragalus adsurgens), ryegrass (Lolium perenne L.), and Bermuda grass (Cynodon dactylon) were planted in the tailings and sprayed with chemical dust suppressants. The growth status of the plants and their effects on the mechanical properties of tailings were also studied. The results show that the weight loss of tailings was stabilized by halides and polymers, and decreased with increasing concentration and spraying amount of the solutions. The penetration resistance of tailings stabilized by halides and polymers increased with increasing concentration and spraying amount of the solutions. Among the halides and polymers tested, the use of CaCl2 and PAM resulted in the best control of tailings dust, respectively. CaCl2 solution reduces the adaptability of plants and therefore makes it difficult for grass seeds to germinate normally. PAM solutions are beneficial for the development of herbaceous plants. Among the three herbaceous species, ryegrass exhibited the best degree of development and was more suitable for growth in the tailings. The ryegrass plants planted in the tailings sprayed with PAM grew the best, and the root-soil complex that formed increased the shear strength of the tailings.


Assuntos
Poeira , Lolium , Lolium/efeitos dos fármacos , Cynodon , Astrágalo , Cloreto de Cálcio , Cloreto de Magnésio/farmacologia , Cloreto de Sódio/química , Resinas Acrílicas/química , Resíduos Industriais , Polímeros , Poaceae , Lignina/análogos & derivados
8.
Nat Commun ; 15(1): 5902, 2024 Jul 13.
Artigo em Inglês | MEDLINE | ID: mdl-39003266

RESUMO

Analogous of pixels to two-dimensional pictures, voxels-in the form of either small cubes or spheres-are the basic building blocks of three-dimensional objects. However, precise manipulation of viscoelastic bio-ink voxels in three-dimensional space represents a grand challenge in both soft matter science and biomanufacturing. Here, we present a voxelated bioprinting technology that enables the digital assembly of interpenetrating double-network hydrogel droplets made of polyacrylamide/alginate-based or hyaluronic acid/alginate-based polymers. The hydrogels are crosslinked via additive-free and biofriendly click reaction between a pair of stoichiometrically matched polymers carrying norbornene and tetrazine groups, respectively. We develop theoretical frameworks to describe the crosslinking kinetics and stiffness of the hydrogels, and construct a diagram-of-state to delineate their mechanical properties. Multi-channel print nozzles are developed to allow on-demand mixing of highly viscoelastic bio-inks without significantly impairing cell viability. Further, we showcase the distinctive capability of voxelated bioprinting by creating highly complex three-dimensional structures such as a hollow sphere composed of interconnected yet distinguishable hydrogel particles. Finally, we validate the cytocompatibility and in vivo stability of the printed double-network scaffolds through cell encapsulation and animal transplantation.


Assuntos
Resinas Acrílicas , Alginatos , Bioimpressão , Ácido Hialurônico , Hidrogéis , Bioimpressão/métodos , Hidrogéis/química , Alginatos/química , Animais , Ácido Hialurônico/química , Resinas Acrílicas/química , Camundongos , Tinta , Impressão Tridimensional , Humanos , Engenharia Tecidual/métodos , Sobrevivência Celular , Materiais Biocompatíveis/química
9.
Methods Mol Biol ; 2805: 31-50, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-39008173

RESUMO

Cell patterning for 3D culture has increased our understanding of how cells interact among themselves and with their environment during tissue morphogenesis. Building cell communities from the bottom up with size and compositional control is invaluable for studies of morphological transitions. Here, we detail Photolithographic DNA-programmed Assembly of Cells (pDPAC). pDPAC uses a photoactive polyacrylamide gel substrate to capture single-stranded DNA on a 2D surface in large-scale, highly resolved patterns using the photomask technology. Cells are then functionalized with a complementary DNA strand, enabling cells to be temporarily adhered to distinct locations only where their complementary strand is patterned. These temporary 2D patterns can be transferred to extracellular matrix hydrogels for 3D culture of cells in biomimetic microenvironments. Use of a polyacrylamide substrate has advantages, including a simpler photolithography workflow, lower non-specific cell adhesion, and lower stiction to ECM hydrogels during release of patterned hydrogels. The protocol is equally applicable to large (cm)-scale patterns and repetitive arrays of smaller-scale cell interaction or migration experiments.


Assuntos
Hidrogéis , Engenharia Tecidual , Hidrogéis/química , Humanos , Engenharia Tecidual/métodos , Resinas Acrílicas/química , Adesão Celular , Matriz Extracelular/metabolismo , Matriz Extracelular/química , Técnicas de Cultura de Células/métodos , Animais , Técnicas de Cultura de Células em Três Dimensões/métodos
10.
Eur J Obstet Gynecol Reprod Biol ; 299: 303-308, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38950453

RESUMO

OBJECTIVES: This TRIPLE study was aimed to evaluate the efficacy of polycarbophil vaginal gel (PCV) in treating symptoms of vaginal atrophy (VA) of peri- and post-menopausal women. MATERIALS AND METHODS: Sexually active women in peri- (n = 29) and post-menopause (n = 54) suffering from VA, were progressively enrolled and treated for 30 days with PCV. Those wishing to continue (n = 73) were treated for additional 180 days. PCV was administered as one application twice a week. The vaginal health index (VHI; range 5 to 25) and the visual analogue score (VAS range for 0 to 100 mm for each item) for vaginal dryness, irritation, and pain at intercourse, along with the global symptoms score (GSS; range 1 to 15) and treatment safety, were evaluated at baseline and after 30 days. In those continuing the treatment an evaluation was performed after additional 180 days. RESULTS: Women in peri and post-menopause were of 48.7 ± 3.3 years and 57.5 ± 5.7 years old., respectively. At baseline all outcomes were significantly worse (p<0.002) in postmenopausal group, except the VHI (p < 0.056). After 30 days VHI increased (p < 0.001) of 4.1 ± 0.5 (mean ± SE), and 5.1 ± 0.4 in peri- and post-menopausal women respectively. VAS of vaginal dryness decreased (p < 0.001) of -24.4 ± 3.6, and -52.7 ± 2.6 (p < 0.001), VAS of irritation decreased (p<0.001) of -18.6 ± 4.4 and -47.8 ± 3.2, VAS of pain decreased (p < 0.001) of -26.2 ± 4.3 and -55.6 ± 3.1 and the GSS decreased (p < 0.001) of -3.9 ± 0.3, and -4.9 ± 0.2, in peri and post-menopausal women, respectively. All the modifications were significantly greater (p < 0.001)(p < 0.032 for GSS) in postmenopausal women, and after 30 days all outcomes were similar in the two groups of women. In comparison to baseline, after 210 days of treatment VHI increased of 7.7 ± 0.3 (p < 0.001), VAS of vaginal dryness decreased of -53.6 ± 1.9 (p < 0.001) VAS of irritation of -42.6 ± 1.4 (p < 0.001) VAS of pain of -46.7 ± 2.3 (p < 0.001) and the GSS of -6.5 ± 0.2 ± 0.2 (p < 0.001). All outcomes improved (p < 0.001) over the values observed after 30 days of treatment (p < 0.001). No side effect was reported. CONCLUSIONS: In peri- and post-menopausal women PCV administration rapidly improves VA symptoms, and its prolongation up to 6 months further increases its efficacy.


Assuntos
Resinas Acrílicas , Atrofia , Pós-Menopausa , Vagina , Cremes, Espumas e Géis Vaginais , Doenças Vaginais , Humanos , Feminino , Atrofia/tratamento farmacológico , Cremes, Espumas e Géis Vaginais/administração & dosagem , Pessoa de Meia-Idade , Vagina/patologia , Vagina/efeitos dos fármacos , Resinas Acrílicas/administração & dosagem , Resinas Acrílicas/uso terapêutico , Doenças Vaginais/tratamento farmacológico , Doenças Vaginais/patologia , Perimenopausa , Administração Intravaginal , Resultado do Tratamento , Adulto
11.
Proc Natl Acad Sci U S A ; 121(28): e2317711121, 2024 Jul 09.
Artigo em Inglês | MEDLINE | ID: mdl-38968101

RESUMO

Adult neural stem cells (NSCs) reside in the dentate gyrus of the hippocampus, and their capacity to generate neurons and glia plays a role in learning and memory. In addition, neurodegenerative diseases are known to be caused by a loss of neurons and glial cells, resulting in a need to better understand stem cell fate commitment processes. We previously showed that NSC fate commitment toward a neuronal or glial lineage is strongly influenced by extracellular matrix stiffness, a property of elastic materials. However, tissues in vivo are not purely elastic and have varying degrees of viscous character. Relatively little is known about how the viscoelastic properties of the substrate impact NSC fate commitment. Here, we introduce a polyacrylamide-based cell culture platform that incorporates mismatched DNA oligonucleotide-based cross-links as well as covalent cross-links. This platform allows for tunable viscous stress relaxation properties via variation in the number of mismatched base pairs. We find that NSCs exhibit increased astrocytic differentiation as the degree of stress relaxation is increased. Furthermore, culturing NSCs on increasingly stress-relaxing substrates impacts cytoskeletal dynamics by decreasing intracellular actin flow rates and stimulating cyclic activation of the mechanosensitive protein RhoA. Additionally, inhibition of motor-clutch model components such as myosin II and focal adhesion kinase partially or completely reverts cells to lineage distributions observed on elastic substrates. Collectively, our results introduce a unique system for controlling matrix stress relaxation properties and offer insight into how NSCs integrate viscoelastic cues to direct fate commitment.


Assuntos
Diferenciação Celular , Células-Tronco Neurais , Células-Tronco Neurais/citologia , Células-Tronco Neurais/metabolismo , Células-Tronco Neurais/fisiologia , Animais , Astrócitos/citologia , Astrócitos/metabolismo , Astrócitos/fisiologia , Camundongos , Resinas Acrílicas/química , Proteína rhoA de Ligação ao GTP/metabolismo , Células Cultivadas , Neurônios/metabolismo , Neurônios/fisiologia , Neurônios/citologia , Matriz Extracelular/metabolismo , Estresse Mecânico
12.
Biomed Phys Eng Express ; 10(5)2024 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-38959871

RESUMO

Biocompatible polymer-based scaffolds hold great promise for neural repair, especially when they are coupled with electrostimulation to induce neural differentiation. In this study, a combination of polyacrylonitrile/polyaniline (PAN/PANI) and Carbon Nanotubes (CNTs) were used to fabricate three different biomimetic electrospun scaffolds (samples 1, 2 and 3 containing 0.26 wt%, 1 wt% and 2 wt% of CNTs, respectively). These scaffolds underwent thorough characterization for assessing electroconductivity, tensile strength, wettability, degradability, swelling, XRD, and FTIR data. Notably, scanning electron microscopy (SEM) images revealed a three-dimensional scaffold morphology with aligned fibers ranging from 60 nm to 292 nm in diameter. To comprehensively investigate the impact of electrical stimulation on the nervous differentiation of the stem cells seeded on these scaffolds, cell morphology and adhesion were assessed based on SEM images. Additionally, scaffold biocompatibility was studied through MTT assay. Importantly, Real-Time PCR results indicated the expression of neural markers-Nestin,ß-tubulin III, and MAP2-by the cells cultured on these samples. In comparison with the control group, samples 1 and 2 exhibited significant increases in Nestin marker expression, indicating early stages of neuronal differentiation, whileß-tubulin III expression was significantly reduced and MAP2 expression remained statistically unchanged. In contrast, sample 3 did not display a statistically significant upturn in Nestin maker expression, while showcasing remarkable increases in the expression of both MAP2 andß-tubulin III, as markers of the end stages of differentiation, leading to postmitotic neurons. These results could be attributed to the higher electroconductivity of S3 compared to other samples. Our findings highlight the biomimetic potential of the prepared scaffolds for neural repair, illustrating their effectiveness in guiding stem cell differentiation toward a neural lineage.


Assuntos
Resinas Acrílicas , Compostos de Anilina , Diferenciação Celular , Nanotubos de Carbono , Regeneração Nervosa , Engenharia Tecidual , Alicerces Teciduais , Alicerces Teciduais/química , Nanotubos de Carbono/química , Compostos de Anilina/química , Resinas Acrílicas/química , Engenharia Tecidual/métodos , Materiais Biocompatíveis/química , Estimulação Elétrica , Humanos , Adesão Celular , Microscopia Eletrônica de Varredura , Células-Tronco/citologia , Resistência à Tração , Neurônios/metabolismo , Neurônios/citologia , Animais , Nestina/metabolismo
13.
J Vis Exp ; (208)2024 Jun 28.
Artigo em Inglês | MEDLINE | ID: mdl-39007608

RESUMO

Viscoelastic behavior can be beneficial in enhancing the unprecedented dynamics of polymer metamaterials or, in contrast, negatively impacting their wave control mechanisms. It is, therefore, crucial to properly characterize the viscoelastic properties of a polymer metamaterial at its working frequencies to understand viscoelastic effects. However, the viscoelasticity of polymers is a complex phenomenon, and the data on storage and loss moduli at ultrasonic frequencies are extremely limited, especially for additively manufactured polymers. This work presents a protocol to experimentally characterize the viscoelastic properties of additively manufactured polymers and to use them in the numerical analysis of polymer metamaterials. Specifically, the protocol includes the description of the manufacturing process, experimental procedures to measure the thermal, viscoelastic, and mechanical properties of additively manufactured polymers, and an approach to use these properties in finite-element simulations of the metamaterial dynamics. The numerical results are validated in ultrasonic transmission tests. To exemplify the protocol, the analysis is focused on acrylonitrile butadiene styrene (ABS) and aims at characterizing the dynamic behavior of a simple metamaterial made from it by using fused deposition modeling (FDM) three-dimensional (3D) printing. The proposed protocol will be helpful for many researchers to estimate viscous losses in 3D-printed polymer elastic metamaterials that will improve the understanding of material-property relations for viscoelastic metamaterials and eventually stimulate the use of 3D-printed polymer metamaterial parts in various applications.


Assuntos
Elasticidade , Viscosidade , Impressão Tridimensional , Butadienos/química , Polímeros/química , Resinas Acrílicas/química , Análise de Elementos Finitos , Manufaturas , Poliestirenos
14.
PLoS One ; 19(7): e0306862, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38990802

RESUMO

To evaluate the effect of antiseptic soap on single and dual-species biofilms of Candida albicans and Streptococcus mutans on denture base and reline resins. Samples of the resins were distributed into groups (n = 9) according to the prevention or disinfection protocols. In the prevention protocol, samples were immersed in the solutions (Lifebuoy, 0.5% sodium hypochlorite solution and PBS) for 7, 14 and 28 days before the single and dual-species biofilms formation. Overnight denture disinfection was simulated. In the disinfection protocol, samples were immersed in the same solutions during 8 hours after the single and dual-species biofilms formation. Antimicrobial activity was analyzed by counting colony-forming units (CFU/mL) and evaluating cell metabolism. Cell viability and protein components of the biofilm matrix were evaluated using confocal laser scanning microscopy (CLSM). Data were submitted to ANOVA, followed by Tukey's post-test (α = 0.05) or Dunnett's T3 multiple comparisons test. In the prevention protocol, Lifebuoy solution effectively reduced the number of CFU/mL of both species. In addition, the solution decreased the cell metabolism of the microorganisms. Regarding disinfection protocol, the Lifebuoy solution was able of reduce approximately of 2-3 logs for all the biofilms on the denture base and reline resin. Cellular metabolism was also reduced. The images obtained with CLSM corroborate these results. Lifebuoy solution was effective in reducing single and dual-species biofilms on denture base and reline resins.


Assuntos
Resinas Acrílicas , Biofilmes , Candida albicans , Bases de Dentadura , Streptococcus mutans , Biofilmes/efeitos dos fármacos , Biofilmes/crescimento & desenvolvimento , Streptococcus mutans/efeitos dos fármacos , Streptococcus mutans/fisiologia , Candida albicans/efeitos dos fármacos , Candida albicans/fisiologia , Bases de Dentadura/microbiologia , Resinas Acrílicas/química , Resinas Acrílicas/farmacologia , Anti-Infecciosos Locais/farmacologia , Desinfecção/métodos , Humanos
15.
Curr Protoc ; 4(7): e1089, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-39034855

RESUMO

Optical imaging technologies and cell targeting have played a major role in detecting and treating diseases such as cancer. Bioharmonophores are optical imaging nanoprobes composed of biodegradable polymer-encapsulated, self-assembling triphenylalanine peptides. They produce a strong second harmonic generation (SHG) signal, a non-linear optical process in which two photons directed at a non-centrosymmetric medium combine to form a new photon with twice the energy. Bioharmonophores demonstrate superior optical properties compared to fluorescent probes and, unlike previously developed inorganic SHG nanoprobes, are both biocompatible and biodegradable. Here, we present a protocol providing five detailed procedures that describe (1) synthesis of bioharmonophores; (2) embedding and imaging of the synthesized SHG nanoprobes in polyacrylamide gel; (3) functionalization of bioharmonophores with thiol-containing polyethyleneglycol; (4) subsequent click chemistry to target cancer cells; and (5) imaging of functionalized bioharmonophores endocytosed by cancer cells using two-photon microscopy. Bioharmonophores hold great potential as clinical contrast agents due to their optical features and could be used in the future as an innovative approach to cancer treatment using targeted high-resolution optical imaging. © 2024 The Author(s). Current Protocols published by Wiley Periodicals LLC. Basic Protocol 1: Synthesis of bioharmonophores Basic Protocol 2: Imaging of bioharmonophores in polyacrylamide gel Basic Protocol 3: Functionalization of bioharmonophores with thiol-PEG Basic Protocol 4: Functionalization of thiol-PEGylated bioharmonophores with peptides Basic Protocol 5: Targeting of cancer cells with functionalized bioharmonophores.


Assuntos
Imagem Óptica , Humanos , Nanopartículas/química , Resinas Acrílicas/química , Resinas Acrílicas/síntese química , Peptídeos/química , Peptídeos/síntese química , Neoplasias/patologia , Corantes Fluorescentes/química , Corantes Fluorescentes/síntese química , Linhagem Celular Tumoral , Química Click/métodos
16.
J Sep Sci ; 47(14): e2400314, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-39034893

RESUMO

In this work, a novel electrospun nanofiber (PAN/TpBD; 2,4,6-triformylphloroglucinol [Tp] and benzidine [BD]; polyacrylonitrile [PAN]) was fabricated via a facile electrospinning method and utilized as adsorbent in thin film microextraction (TFME) of phthalate esters (PAEs) (dimethyl phthalate, diethyl phthalate, diallyl phthalate, dibutyl phthalate, and dioctyl phthalate) in biodegradable plastics. The prepared PAN/TpBD combines the strong stability of nanofibers with increased exposure sites for covalent organic frameworks and enhanced interactions with the target, thus improving the enrichment effect on the target. The extraction efficiency of PAN/TpBD reached above 80%. Based on PAN/TpBD, a TFME-high-performance liquid chromatography method was established, and the experimental parameters were optimized. Under the optimal extraction conditions, the PAEs of this method varied linearly in the range of 10-10 000 µg/L with low detection limits (0.69-2.72 µg/L). The intra-day and inter-day relative standard deviation values of the PAEs were less than 8.04% and 8.73%, respectively. The adsorbent can achieve more than 80% recovery of the five targets after six times reuse. The developed method was successfully applied for the determination of trace PAEs in biodegradable plastics with recoveries ranging from 80.1% to 113.4% and relative standard deviations were less than 9.45%. The as-synthesized PAN/TpBD adsorbent exhibited great potential in PAE analysis.


Assuntos
Ésteres , Nanofibras , Ácidos Ftálicos , Nanofibras/química , Ácidos Ftálicos/isolamento & purificação , Ácidos Ftálicos/química , Ácidos Ftálicos/análise , Ésteres/química , Ésteres/isolamento & purificação , Ésteres/análise , Plásticos/química , Cromatografia Líquida de Alta Pressão , Tamanho da Partícula , Adsorção , Microextração em Fase Sólida/métodos , Propriedades de Superfície , Resinas Acrílicas
17.
J Mater Chem B ; 12(25): 6164-6174, 2024 Jun 27.
Artigo em Inglês | MEDLINE | ID: mdl-38828762

RESUMO

Catalytic therapy based on nanozymes is promising for the treatment of bacterial infections. However, its therapeutic efficacy is usually restricted by the limited amount of hydrogen peroxide and the weak acidic environment in infected tissues. To solve these issues, we prepared polyvinyl alcohol (PVA)-polyacrylic acid (PAA)-iron oxide (Fe3O4)/polyvinyl alcohol (PVA)-zinc peroxide (ZnO2) double-layer electrospun nanofibers (PPF/PZ NFs). In this design, PVA serves as the carrier for ZnO2 nanoparticles (NPs), Fe3O4 NPs, and PAA. The double-layer structure of nanofibers can spatially separate the PAA and ZnO2 to avoid their reaction with each other during preparation and storage, while in the wet wound bed, PVA can dissolve and PAA can provide H+ ions to promote the generation of hydrogen peroxide and subsequent conversion to hydroxyl radicals for bacteria killing. In vitro experimental results demonstrated that PPF/PZ NFs can reduce the methicillin-resistant Staphylococcus aureus by 3.1 log (99.92%). Moreover, PPF/PZ NFs can efficiently treat the bacterial infection in a mouse wound model and promote wound healing with negligible toxicity to animals, indicating their potential use as "plug-and-play" antibacterial wound dressings. This work provides a novel strategy for the construction of double-layer electrospun nanofibers as catalytic wound dressings with hydrogen peroxide/acid self-supplying properties for the efficient treatment of bacterial infections.


Assuntos
Antibacterianos , Peróxido de Hidrogênio , Staphylococcus aureus Resistente à Meticilina , Nanofibras , Infecção dos Ferimentos , Óxido de Zinco , Nanofibras/química , Animais , Camundongos , Peróxido de Hidrogênio/química , Peróxido de Hidrogênio/farmacologia , Catálise , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Antibacterianos/química , Antibacterianos/farmacologia , Infecção dos Ferimentos/tratamento farmacológico , Óxido de Zinco/química , Óxido de Zinco/farmacologia , Álcool de Polivinil/química , Resinas Acrílicas/química , Resinas Acrílicas/farmacologia , Cicatrização/efeitos dos fármacos , Testes de Sensibilidade Microbiana , Infecções Estafilocócicas/tratamento farmacológico , Tamanho da Partícula
18.
ACS Sens ; 9(6): 3085-3095, 2024 Jun 28.
Artigo em Inglês | MEDLINE | ID: mdl-38840550

RESUMO

Wearable gas sensors have drawn great attention for potential applications in health monitoring, minienvironment detection, and advanced soft electronic noses. However, it still remains a great challenge to simultaneously achieve excellent flexibility, high sensitivity, robustness, and gas permeability, because of the inherent limitation of widely used traditional organic flexible substrates. Herein, an electrospinning polyacrylonitrile (PAN) nanofiber network was designed as a flexible substrate, on which an ultraflexible wearable gas sensor was prepared with in situ assembled polyaniline (PANI) and multiwalled carbon nanotubes (MWCNTs) as a sensitive layer. The unique nanofiber network and strong binding force between substrate and sensing materials endow the wearable gas sensor with excellent robustness, flexibility, and gas permeability. The wearable sensor can maintain stable NH3 sensing performance while sustaining extreme bending and stretching (50% of strain). The Young's modulus of wearable PAN/MWCNTs/PANI sensor is as low as 18.9 MPa, which is several orders of magnitude smaller than those of reported flexible sensors. The water vapor transmission rate of the sensor is 0.38 g/(cm2 24 h), which enables the wearing comfort of the sensor. Most importantly, due to the effective exposure of sensing sites as well as the heterostructure effect between MWCNTs and PANI, the sensor shows high sensitivity to NH3 at room temperature, and the theoretical limit of detection is as low as 300 ppb. This work provides a new avenue for the realization of reliable and high-performance wearable gas sensors.


Assuntos
Resinas Acrílicas , Amônia , Compostos de Anilina , Nanofibras , Nanotubos de Carbono , Dispositivos Eletrônicos Vestíveis , Nanofibras/química , Nanotubos de Carbono/química , Compostos de Anilina/química , Resinas Acrílicas/química , Amônia/análise , Humanos , Gases/análise , Gases/química
19.
Am J Dent ; 37(3): 126-130, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38899991

RESUMO

PURPOSE: To evaluate the antimicrobial activity of dentifrices based on Malva sylvestris and propolis and the effect on the acrylic resin. METHODS: The inhibitory effect against Candida albicans, Enterococcus faecalis and Streptococcus mutans was determined. The specimens of resin were divided into groups: Control (brushing with distilled water); brushing with Colgate; brushing with Protex; brushing with Malvatricin, brushing with Proporalcare Dental Gel and brushing with Green Propolis Dental Gel. Brushing was carried out in a brushing machine. Roughness and color were assessed. The data were analyzed by ANOVA, followed by the Bonferroni post test (α= 0.05). RESULTS: The products evaluated showed antimicrobial activity against all microorganisms (P< 0.05), except Proporalcare Dental Gel, which was not effective against E. faecalis. Greater roughness (P< 0.05) was observed in the samples treated with Colgate. The samples from control and Protex groups showed the lowest color variation and the highest luminosity, with a difference in relation to the others (P< 0.05), which showed higher values, although clinically acceptable. CLINICAL SIGNIFICANCE: The dentifrices based on natural products can be indicated for cleaning prostheses, since they showed antimicrobial activity and did not cause perceptible color changes of the resin tested. The dentifrices did not produce adverse effects on the surface of the resin or did so less than the conventional dentifrice.


Assuntos
Resinas Acrílicas , Candida albicans , Dentifrícios , Bases de Dentadura , Streptococcus mutans , Dentifrícios/farmacologia , Streptococcus mutans/efeitos dos fármacos , Candida albicans/efeitos dos fármacos , Enterococcus faecalis/efeitos dos fármacos , Própole/farmacologia , Propriedades de Superfície , Teste de Materiais , Cor , Humanos , Anti-Infecciosos/farmacologia , Escovação Dentária , Cremes Dentais/farmacologia , Cremes Dentais/química , Ácido Silícico
20.
BMC Oral Health ; 24(1): 672, 2024 Jun 08.
Artigo em Inglês | MEDLINE | ID: mdl-38851676

RESUMO

BACKGROUND: This crossover clinical study aimed to evaluate and compare masticatory performance and patient satisfaction for patients rehabilitated with conventional heat-cured acrylic resin and 3D-printed mandibular implant overdentures retained with bar attachment. MATERIALS AND METHODS: Sixteen completely edentulous healthy participants received new conventional dentures. In the mandible, four interforaminal implants were inserted. Following the stage of osseointegration, the bar was constructed in a trapezoidal configuration. Each patient randomly received the following overdentures using a crossover design: (1) conventional heat-cured acrylic resin overdenture and (2) 3D-printed overdenture (developed by scanning of mandibular conventional overdenture). The masticatory performance was assessed by conducting a two-colour mixing ability test at 5, 10, 20, 30, and 50 masticatory cycles. Moreover, the McGill Denture Satisfaction Questionnaire (MDSQ) was employed to assess patient satisfaction. Evaluation was performed after 3 months of using each overdenture. Paired sample t tests were used to compare the masticatory performance and MDSQ scores of patients for both prostheses. RESULTS: No significant difference in masticatory performance was reported between the two types of overdentures. Regarding patient satisfaction, only the esthetic aspect was significantly better for conventionally processed overdentures than for printed overdentures. Insignificant differences were observed regarding other MDSQ items between the two overdentures. CONCLUSION: Within this clinical study, 3D-printed implant overdentures showed promising results in terms of chewing efficiency and patient satisfaction compared to conventionally fabricated implant overdentures. TRIAL REGISTRATION: Retrospectively registered at www. CLINICALTRIALS: gov : NCT06148727.(28/11/2023).


Assuntos
Estudos Cross-Over , Prótese Dentária Fixada por Implante , Revestimento de Dentadura , Mastigação , Satisfação do Paciente , Impressão Tridimensional , Humanos , Mastigação/fisiologia , Masculino , Feminino , Pessoa de Meia-Idade , Idoso , Mandíbula , Resinas Acrílicas
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