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1.
Int J Pharm ; 661: 124409, 2024 Jun 30.
Artículo en Inglés | MEDLINE | ID: mdl-38955241

RESUMEN

Lipid-based nanocarriers have been extensively utilized for the solubilization and cutaneous delivery of water-insoluble active ingredients in skincare formulations. However, their practical application is often limited by structural instability, leading to premature release and degradation of actives. Here we present highly robust multilamellar nanovesicles, prepared by the polyionic self-assembly of unilamellar vesicles with hydrolyzed collagen peptides, to stabilize all-trans-retinol and enhance its cutaneous delivery. Our results reveal that the reinforced multilayer structure substantially enhances dispersion stability under extremely harsh conditions, like freeze-thaw cycles, and stabilizes the encapsulated retinol. Interestingly, these multilamellar vesicles exhibit significantly lower cytotoxicity to human dermal fibroblasts than their unilamellar counterparts, likely due to their smaller particle number per weight, minimizing potential disruptions to cellular membranes. In artificial skin models, retinol-loaded multilamellar vesicles effectively upregulate collagen-related gene expression while suppressing the synthesis of metalloproteinases. These findings suggest that the robust multilamellar vesicles can serve as effective nanocarriers for the efficient delivery and stabilization of bioactive compounds in cutaneous applications.

2.
Adv Sci (Weinh) ; : e2400111, 2024 Jul 12.
Artículo en Inglés | MEDLINE | ID: mdl-38995098

RESUMEN

Reconstructed epidermal equivalents (REEs) consist of two distinct cell layers - the stratum corneum (SC) and the keratinocyte layer (KL). The interplay of these layers is particularly crucial in pruritic inflammatory disorders, like psoriasis, where a defective SC barrier is associated with immune dysregulation. However, independent evaluation of the skin barrier function of the SC and KL in REEs is highly challenging because of the lack of quantitative methodologies that do not disrupt the counter layer. Here, a non-invasive impedance spectroscopy technique is introduced for dissecting the distinct contributions of the SC and KL to overall skin barrier function without disrupting the structure. These findings, inferred from the impedance spectra, highlight the individual barrier resistances and maturation levels of each layer. Using an equivalent circuit model, a correlation between impedance parameters and specific skin layers, offering insights beyond traditional impedance methods that address full-thickness skin only is established. This approach successfully detects subtle changes, such as increased paracellular permeability due to mild irritants and the characterization of an immature SC in psoriatic models. This research has significant implications, paving the way for detailed mechanistic investigations and fostering the development of therapies for skin irritation and inflammatory disorders.

3.
Adv Healthc Mater ; : e2401483, 2024 Jun 18.
Artículo en Inglés | MEDLINE | ID: mdl-38889395

RESUMEN

MicroRNAs (miRNAs) serve as emerging biomarkers for a range of diseases, and their quantitative analysis draws increasing attention. Yet, current invasive methods limit continuous tracking within living cells. To overcome this, a nonenzymatic DNA-based nanoprobe is developed for dynamic, noninvasive miRNA tracking via live-cell imaging. This probe features a unique hairpin DNA structure with five guanines that act as internal quenchers, suppressing fluorescence from an attached fluorophore via photoinduced electron transfer. Target miRNA initiates toehold-mediated strand displacement, restoring, and amplifying the fluorescence signal. Additionally, by introducing a single mismatch to the hairpin DNA, the nanoprobe's sensitivity is significantly enhanced, lowering the detection limit to about 60 pM without compromising specificity. To optimize intracellular delivery for prolonged monitoring, the nanoprobe is encapsulated within multilamellar lipid nanovesicles, fluorescently labeled for dual-wavelength ratiometric analysis. The proposed nanoprobe demonstrates a significant advance in live-cell miRNA detection, promising enhanced in situ analysis for a better understanding of miRNAs' pathophysiological function.

4.
Adv Healthc Mater ; 13(18): e2304109, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-38849130

RESUMEN

Lipid vesicles are widely used for drug and gene delivery, but their structural instability reduces in vivo efficacy and requires specialized handling. To address these limitations, strategies like lipid cross-linking and polymer-lipid conjugation are suggested to enhance stability and biological efficacy. However, the in vivo metabolism of these altered lipids remains unclear, necessitating further studies. A new stabilization technique without chemical modification is urgently needed. Here, a bio-mimetic approach for fabricating robust multilamellar lipid vesicles to enhance in vivo delivery and stabilization of protein antigens is presented. This method leverages 1-O-acylceramide, a natural skin lipid, to facilitate the self-assembly of lipid nanovesicles. Incorporating 1-O-acylceramide, anchoring lipid bilayers akin to its role in the stratum corneum, provides excellent stability under environmental stresses, including freeze-thaw cycles. Encapsulating ovalbumin as a model antigen and the adjuvant monophosphoryl lipid A demonstrates the vesicle's potential as a nanovaccine platform. In vitro studies show enhanced immune responses with both unilamellar and multilamellar vesicles, but in vivo analyses highlight the superior efficiency of multilamellar vesicles in inducing higher antibody and cytokine levels. This work suggests ceramide-induced multilamellar lipid vesicles as an effective nanovaccine platform for enhanced antigen delivery and stability.


Asunto(s)
Ovalbúmina , Animales , Ratones , Ovalbúmina/química , Ovalbúmina/inmunología , Materiales Biomiméticos/química , Materiales Biomiméticos/farmacología , Vacunación/métodos , Lípido A/química , Lípido A/análogos & derivados , Vacunas/química , Vacunas/inmunología , Ceramidas/química , Lípidos/química , Nanopartículas/química , Femenino , Ratones Endogámicos C57BL
5.
J Phys Chem B ; 128(22): 5378-5386, 2024 Jun 06.
Artículo en Inglés | MEDLINE | ID: mdl-38805566

RESUMEN

The extracellular lipid matrix in the stratum corneum (SC) plays a critical role in skin barrier functionality, comprising three primary components: ceramides, cholesterol, and free fatty acids. The diverse ceramides, differentiated by molecular structures such as hydroxylations and varying chain lengths, are essential for the lipid matrix's structural integrity. Recently, a new subclass of ceramide, 1-O-acylceramide NP (CerENP), has been identified; however, its precise role in the lipid matrix of the SC is still elusive. Herein, we investigate the role of CerENP on the structure and permeability of the SC using molecular dynamics simulations. Our findings indicate that CerENP contributes to a compact lipid matrix in the lateral dimension of our SC model with a repeat distance of about 13 nm. Additionally, ethanol permeability assessments show that CerENP effectively reduces molecular penetration through the lipid matrix. This study provides an insight into the role of a new subclass of ceramide in the SC, enhancing our understanding of skin structure and the mechanisms behind barrier dysfunction in skin diseases.


Asunto(s)
Ceramidas , Simulación de Dinámica Molecular , Ceramidas/química , Epidermis/metabolismo , Epidermis/química , Permeabilidad , Humanos , Piel/metabolismo , Piel/química , Lípidos/química , Etanol/química
6.
Artículo en Inglés | MEDLINE | ID: mdl-38514461

RESUMEN

BACKGROUND AND AIMS: Louse-borne Bartonella quintana infection and flea-borne murine typhus are two potentially serious vector-borne diseases that have led to periodic outbreaks among people experiencing homelessness in the United States. Little is known about louse- and flea-borne disease awareness and prevention among staff who provide services to the population. We surveyed staff in seven US states to identify gaps in knowledge and prevention practices for these diseases. METHODS AND RESULTS: Surveys were administered to 333 staff at 89 homeless shelters and outreach teams in California, Colorado, Georgia, Maryland, Minnesota, New York and Washington from August 2022 to April 2023. Most participants (>68%) agreed that body lice and fleas are a problem for people experiencing homelessness. About half were aware that diseases could be transmitted by these vectors; however, most could not accurately identify which diseases. Less than a quarter of staff could describe an appropriate protocol for managing body lice or fleas. Misconceptions included that clients must isolate or be denied services until they are medically cleared. CONCLUSIONS: Our findings reveal significant knowledge gaps among staff who provide services to people experiencing homelessness in the prevention and control of louse- and flea-borne diseases. This demonstrates an urgent need for staff training to both reduce disease and prevent unnecessary restrictions on services and housing.

7.
ACS Appl Mater Interfaces ; 16(13): 16086-16095, 2024 Apr 03.
Artículo en Inglés | MEDLINE | ID: mdl-38506502

RESUMEN

Solar water oxidation is a crucial process in light-driven reductive synthesis, providing electrons and protons for various chemical reductions. Despite advances in light-harvesting materials and cocatalysts, achieving high efficiency and stability remains challenging. In this study, we present a simple yet effective strategy for immobilizing natural photosystems (PS) made of abundant and inexpensive elements, using amine-rich polyethylenimine (PEI) hydrogels, to fabricate organic/inorganic hybrid photoanodes. Natural PS II extracted from spinach was successfully immobilized on inverse opal TiO2 photoanodes in the presence of PEI hydrogels, leading to greatly enhanced solar water oxidation activity. Photoelectrochemical (PEC) analyses reveal that PS II can be immobilized in specific orientations through electrostatic interactions between the positively charged amine groups of PEI and the negatively charged stromal side of PS II. This specific orientation ensures efficient photogenerated charge separation and suppresses undesired side reactions such as the production of reactive oxygen species. Our study provides an effective immobilization platform and sheds light on the potential utilization of PS II in PEC water oxidation.

8.
ACS Appl Mater Interfaces ; 16(13): 16767-16777, 2024 Apr 03.
Artículo en Inglés | MEDLINE | ID: mdl-38512769

RESUMEN

Titanium dioxide (TiO2) nanoparticles are extensively used as a sunscreen filter due to their long-active ultraviolet (UV)-blocking performance. However, their practical use is being challenged by high photochemical activities and limited absorption spectrum. Current solutions include the coating of TiO2 with synthetic polymers and formulating a sunscreen product with additional organic UV filters. Unfortunately, these approaches are no longer considered effective because of recent environmental and public health issues. Herein, TiO2-metal-phenolic network hybrid nanoparticles (TiO2-MPN NPs) are developed as the sole active ingredient for sunscreen products through photochemical suppression and absorption spectrum widening. The MPNs are generated by the complexation of tannic acid with multivalent metal ions, forming a robust coating shell. The TiO2-MPN hybridization extends the absorption region to the high-energy-visible (HEV) light range via a new ligand-to-metal charge transfer photoexcitation pathway, boosting both the sun protection factor and ultraviolet-A protection factor about 4-fold. The TiO2-MPN NPs suppressed the photoinduced reactive oxygen species by 99.9% for 6 h under simulated solar irradiation. Accordingly, they substantially alleviated UV- and HEV-induced cytotoxicity of fibroblasts. This work outlines a new tactic for the eco-friendly and biocompatible design of sunscreen agents by selectively inhibiting the photocatalytic activities of semiconductor nanoparticles while broadening their optical spectrum.

9.
ACS Nano ; 18(1): 451-460, 2024 Jan 09.
Artículo en Inglés | MEDLINE | ID: mdl-37971988

RESUMEN

Plasmonic catalysts have the potential to accelerate and control chemical reactions with light by exploiting localized surface plasmon resonances. However, the mechanisms governing plasmonic catalysis are not simple to decouple. Several plasmon-derived phenomena, such as electromagnetic field enhancements, temperature, or the generation of charge carriers, can affect the reactivity of the system. These effects are convoluted with the inherent (nonplasmonic) catalytic properties of the metal surface. Disentangling these coexisting effects is challenging but is the key to rationally controlling reaction pathways and enhancing reaction rates. This study utilizes super-resolution fluorescence microscopy to examine the mechanisms of plasmonic catalysis at the single-particle level. The reduction reaction of resazurin to resorufin in the presence of Au nanorods coated with a porous silica shell is investigated in situ. This allows the determination of reaction rates with a single-molecule sensitivity and subparticle resolution. By variation of the irradiation wavelength, it is possible to examine two different regimes: photoexcitation of the reactant molecules and photoexcitation of the nanoparticle's plasmon resonance. In addition, the measured spatial distribution of reactivity allows differentiation between superficial and far-field effects. Our results indicate that the reduction of resazurin can occur through more than one reaction pathway, being most efficient when the reactant is photoexcited and is in contact with the Au surface. In addition, it was found that the spatial distribution of enhancements varies, depending on the underlying mechanism. These findings contribute to the fundamental understanding of plasmonic catalysis and the rational design of future plasmonic nanocatalysts.

10.
Biomacromolecules ; 24(7): 3043-3050, 2023 07 10.
Artículo en Inglés | MEDLINE | ID: mdl-37283006

RESUMEN

Despite the well-known advantages of lipid vesicles for drug and gene delivery, structural instability limits their practical applications and requires strictly regulated conditions for transport and storage. Chemical crosslinking and in situ polymerization have been suggested to increase the membrane rigidity and dispersion stability of lipid vesicles. However, such chemically modified lipids sacrifice the dynamic nature of lipid vesicles and obfuscate their in vivo metabolic fates. Here, we present highly robust multilamellar lipid vesicles through the self-assembly of preformed, cationic large unilamellar vesicles (LUVs) with hydrolyzed collagen peptides (HCPs). The cationic LUVs undergo vesicle-to-vesicle attachment and structural reorganization through polyionic complexation with HCPs, resulting in the formation of multilamellar collagen-lipid vesicles (MCLVs). The resulting MCLVs exhibit excellent structural stability against variations in pH and ionic strength and the addition of surfactants. Particularly, the MCLVs maintain their structural stability against repeated freeze-thaw stresses, proving the unprecedented stabilization effect of biological macromolecules on lipid lamellar structures. This work provides a practically attractive technique for the simple and quick fabrication of structurally robust lipid nanovesicles without covalent crosslinkers, organic solvents, and specialized instruments.


Asunto(s)
Tensoactivos , Liposomas Unilamelares , Liposomas Unilamelares/química , Tensoactivos/química , Cationes , Lípidos/química , Péptidos , Liposomas/química
11.
Work ; 76(1): 243-249, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-36872817

RESUMEN

BACKGROUND: Oral and maxillofacial surgeons (OMS) are continually required to adjust position and posture to access the limited surgical field in and around the head and neck, oral cavity, and oropharynx. Very limited data exists that quantifies the burden of musculoskeletal disorders (MSD) among OMS. OBJECTIVE: This exploratory study seeks to address these literature gaps by assessing the prevalence of MSD among OMS. METHOD: A 12-question survey was designed to investigate the prevalence of MSD for OMS, including residents in training, actively practicing surgeons, and retired surgeons. Seventy-six surveys were distributed and completed in person by surgeons attending professional conferences from September 2018-September 2019. Survey questions included the Baker-Wong Faces pain scale, years in practice, number of hours worked per week, job tenure, pain attributable to work, and age. The Nordic scale identified and delineated anatomic site of musculoskeletal complaints, duration and treatment sought. RESULTS: The most frequently cited sources and locations of pain attributable to occupation were shoulders, neck, and lower back. The risk of MSD symptoms was relatively two-fold [PR = 2.54, 95% CI = 0.90, 7.22] among OMS in practice for more than ten years compared to those in practice less than ten years. After adjusting for age and hours worked per week as potential confounders, the risk of MSD symptoms was higher among OMS in practice for more than ten years compared to those with less than ten years of experience, despite no statistically significant association. CONCLUSION: OMS are impacted by a high prevalence of MSD. The neck, shoulder, and lower back are the most frequently affected with discomfort and pain. This study found that practicing oral and maxillofacial surgery for more than 10 years is a potential risk factor for experiencing MSD.


Asunto(s)
Enfermedades Musculoesqueléticas , Enfermedades Profesionales , Cirujanos , Humanos , Cirujanos Oromaxilofaciales , Enfermedades Profesionales/epidemiología , Enfermedades Profesionales/prevención & control , Enfermedades Profesionales/etiología , Enfermedades Musculoesqueléticas/epidemiología , Enfermedades Musculoesqueléticas/etiología , Enfermedades Musculoesqueléticas/prevención & control , Encuestas y Cuestionarios , Factores de Riesgo , Dolor , Prevalencia
12.
J Mater Chem B ; 11(13): 2904-2915, 2023 03 30.
Artículo en Inglés | MEDLINE | ID: mdl-36892061

RESUMEN

Polymer coatings containing both fouling-resistant and fouling-release components have been reported to show synergistic antifouling properties. However, it remains unclear how the polymer composition influences the antifouling performance, particularly regarding foulants of different sizes and biological natures. Herein, we prepare dual functionalized brush copolymers containing fouling-resistant poly(ethylene glycol) (PEG) and fouling-release polydimethylsiloxane (PDMS) and examine their antifouling performances against different biofoulants. We utilize poly(pentafluorophenyl acrylate) (PPFPA) as a reactive precursor polymer and graft amine-functionalized PEG and PDMS side chains to create PPFPA-g-PEG-g-PDMS brush copolymers of systematically varying compositions. The copolymer films spin-coated on silicon wafers exhibit surface heterogeneity that can be correlated well with the bulk composition of the copolymer. When the copolymer-coated surfaces are examined against protein (human serum albumin and bovine serum albumin) adsorption and cell (lung cancer cells and microalgae) adhesion, they are found to perform better than the homopolymers. The enhanced antifouling properties are attributed to the copolymers having a PEG-rich top layer and a PEG/PDMS mixed bottom layer that work synergistically to resist biofoulant attachment. Furthermore, the composition of the best-performing copolymer is different for different foulants, with PPFPA-g-PEG39-g-PDMS46 exhibiting the best antifouling properties against proteins and PPFPA-g-PEG54-g-PDMS30 exhibiting the best antifouling properties against cells. We explain this difference by considering the changes in the length scale of the surface heterogeneity in relation to the foulant sizes.


Asunto(s)
Incrustaciones Biológicas , Humanos , Incrustaciones Biológicas/prevención & control , Polímeros/farmacología , Polímeros/química , Polietilenglicoles/química , Albúmina Sérica Bovina/química , Adsorción
13.
J Mater Chem B ; 11(10): 2135-2144, 2023 03 08.
Artículo en Inglés | MEDLINE | ID: mdl-36762491

RESUMEN

This study introduces a multilamellar ceramide core-structured microvehicle platform for substantial skin barrier function recovery. Our approach essentially focused on fabricating bacterial cellulose nanofiber (BCNF)-enveloped ceramide-rich lipid microparticles (CerMPs) by solidifying BCNF-armored oil-in-water Pickering emulsions. The oil drops consisted of Ceramide NP (a phytosphingosine backbone N-acylated with a saturated stearic acid) and fatty alcohols (FAs) with a designated stoichiometry. The thin BCNF shell layer completely blocked the growth of ceramide molecular crystals from the CerMPs for a long time. The CerMP cores displayed a multilamellar structure wherein the interlayer distance and lateral packing could be manipulated using FAs with different alkyl chain lengths. The CerMPs remarkably lowered the trans-epidermal water loss while restoring the structural integrity of the epidermis in damaged skin. The results obtained herein highlight that the CerMP system provides a practical methodology for developing various types of skin-friendly formulations that can strengthen the skin barrier function.


Asunto(s)
Ceramidas , Piel , Ceramidas/química , Recuperación de la Función , Epidermis , Agua/química
14.
Adv Healthc Mater ; 12(9): e2202076, 2023 04.
Artículo en Inglés | MEDLINE | ID: mdl-36579651

RESUMEN

Rapid, sensitive, specific, and user-friendly microRNA (miRNA) assays are in high demand for point-of-care diagnosis. Target-catalyzed toehold-mediated strand displacement (TMSD) has received increasing attention as an enzyme-free molecular tool for DNA detection. However, the application of TMSD to miRNA targets is challenging because relatively weak DNA/RNA hybridization leads to failure in the subtle kinetic control of multiple hybridization steps. Here, a simple method is presented for miRNA assay based on the one-pot self-assembly of Y-shaped DNAs with streptavidin via an miRNA-catalyzed TMSD cascade reaction. A single miRNA catalyzes the opening cycle of DNA hairpin loops to generate multiple Y-shaped DNAs carrying biotin and a quencher at the end of their arms. Introducing a single base-pair mismatch near the toehold facilitates RNA-triggered strand displacement while barely disturbing nonspecific reactions. The Y-shaped DNAs are self-assembled with fluorescently labeled streptavidin (sAv), which produces nanoscale DNA-sAv nanogel particles mediating efficient Förster resonance energy transfer in their 3D network. The enhancing effect dramatically reduces the detection limit from the nanomolar level to the picomolar level. This work proves that TMSD-based DNA nanogel with a base-pair mismatch incorporated to a hairpin structure is a promising approach towards sensitive and accurate miRNA assay.


Asunto(s)
Técnicas Biosensibles , MicroARNs , MicroARNs/genética , Estreptavidina , Nanogeles , ADN/química , Catálisis , Técnicas Biosensibles/métodos
15.
J Photochem Photobiol B ; 235: 112565, 2022 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-36113261

RESUMEN

Photochemical instability and reactivity of organic ultraviolet (UV) filters not only degrade the performance of sunscreen formulations but also generate toxic photodegradation products and reactive oxygen species (ROS). Although the encapsulation of organic UV filters into synthetic polymer particles has been widely investigated, synthetic plastics were recently banned for personal care and cosmetic products due to marine and coastal pollution issues. Here we present a plastic-free, photochemically stable and inactive UV filter platform based on chitosan-coated mesoporous silica microparticles, denoted 'mSOCPs', incorporating octyl methoxycinnamate (OMC) as a sunscreen agent. Sunlight induced the degradation of ∼80% free OMC in artificial sweat in 1 h at room temperature, while only 20% of OMC degraded for 3 h when encapsulated within mSOCPs. Moreover, mSOCPs efficiently suppressed the photochemical generation of ROS by about 99% through the combined effects of the mesoporous silica structure and chitosan coating. Accordingly, mSOCPs substantially increased the cell viability of fibroblasts exposed to UV irradiation. This work demonstrates that the biopolymer coatings of mesoporous inorganic particles can be a promising approach to the plastic-free encapsulation of organic UV filters for suppressing their photochemical reactivity and degradation.


Asunto(s)
Quitosano , Protectores Solares , Estabilidad de Medicamentos , Especies Reactivas de Oxígeno , Dióxido de Silicio/química , Protectores Solares/química , Protectores Solares/farmacología , Rayos Ultravioleta
16.
J Occup Environ Med ; 64(11): e714-e721, 2022 11 01.
Artículo en Inglés | MEDLINE | ID: mdl-36069858

RESUMEN

BACKGROUND: Firefighters are at high-risk of mental health. This study qualitatively assessed the pathways toward mental health in firefighters. METHODS: A two-phased assessment was conducted incorporating in-depth interviews (n = 52) and 10 focus group discussions (n = 82) with firefighters. Thematic analysis was used to develop codes and themes that informed the development of a conceptual model. RESULTS: Firefighters recognized personalizing events by relating calls to their personal lives or prior life experiences as the main risk factor. Department debriefing with fire chiefs or leadership after traumatic events was reported as the primary coping strategy firefighters found most effective. Stigma and lack of medical professionals understanding the firefighter culture were identified as barriers for accessing mental health services or their effectiveness. DISCUSSION: Pathways toward mental health in firefighters were identified that could be used to improve current strategies to protect their well-being.


Asunto(s)
Bomberos , Servicios de Salud Mental , Humanos , Bomberos/psicología , Salud Mental , Adaptación Psicológica , Grupos Focales
17.
Adv Mater ; 34(35): e2200408, 2022 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-35799313

RESUMEN

Biological systems consist of hierarchical protein structures, each of which has unique 3D geometries optimized for specific functions. In the past decades, the growth of inorganic materials on specific proteins has attracted considerable attention. However, the use of specific proteins as templates has only been demonstrated in relatively simple organisms, such as viruses, limiting the range of structures that can be used as scaffolds. This study proposes a method for synthesizing metallic structures that resemble the 3D assemblies of specific proteins in mammalian cells and animal tissues. Using 1.4 nm nanogold-conjugated antibodies, specific proteins within cells and ex vivo tissues are labeled, and then the nanogold acts as nucleation sites for growth of metal particles. As proof of concept, various metal particles are grown using microtubules in cells as templates. The metal-containing cells are applied as catalysts and show catalytic stability in liquid-phase reactions due to the rigid support provided by the microtubules. Finally, this method is used to produce metal structures that replicate the specific protein assemblies of neurons in the mouse brain or the extracellular matrices in the mouse kidney and heart. This new biotemplating approach can facilitate the conversion of specific protein structures into metallic forms in ex vivo multicellular organisms.


Asunto(s)
Mamíferos , Metales , Animales , Catálisis , Metales/química , Ratones
18.
Biosens Bioelectron ; 210: 114288, 2022 Aug 15.
Artículo en Inglés | MEDLINE | ID: mdl-35460968

RESUMEN

Rapid, sensitive, and reliable nucleic acid assay is crucial for the molecular diagnosis of many diseases. For high sensitivity, conventional techniques require time-consuming, high-cost, and complicated procedures, such as enzymatic gene amplification, labeling, and purification, limiting their applications to point-of-care diagnostics. Herein we report a new DNA nanoprobe based on the dual effects of target-specific plasmon-enhanced fluorescence and off-target plasmonic quenching. Janus gold half-shell/polystyrene nanospheres (hsAu/PSs, ∼150 nm diameter) are tethered with capture single-stranded DNA (ssDNA), coupled with a fluorophore-conjugated reporter ssDNA through sandwich-type hybridization with target DNA, resulting in 5-fold increase through plasmon-enhanced fluorescence. Smaller gold nanoparticles (∼13 nm diameter) are subsequently introduced as quenchers to reduce background fluorescence from unhybridized reporter ssDNA, increasing the sensitivity about 103 times. The limit of detection of the dual-mode plasmonic DNA nanoprobe is 16 pM at room temperature in 1 h for the target gene of Klebsiella pneumoniae carbapenemase. The nanoprobe also exhibits a high selectivity enough to discriminate a single-base difference in the target gene. Our strategy harnesses both of the plasmon-mediated fluorescence enhancement and quenching effects through the sophisticated design of nanoscale colloids, which opens a promising avenue to the enzyme-free, simple, sensitive, and selective detection of pathogenic DNA.


Asunto(s)
Técnicas Biosensibles , Nanopartículas del Metal , Técnicas Biosensibles/métodos , ADN , ADN de Cadena Simple , Oro , Hibridación de Ácido Nucleico
19.
J Interpers Violence ; 37(17-18): NP15992-NP16012, 2022 09.
Artículo en Inglés | MEDLINE | ID: mdl-34144668

RESUMEN

Bias-based bullying (e.g., bullying related to race, weight, sexual orientation) is a common experience among youth, yet few school-based prevention programs explicitly address this type of bullying. This study explores whether schools that offer diversity education activities have lower rates of bias-based bullying among students compared to schools that do not offer these activities. Data came from two sources: the 2018 CDC School Profiles Survey (N = 216 schools) and the 2019 Minnesota Student Survey (N = 64,510 students). Multilevel logistic regression tested associations between diversity education activities (diversity clubs, lessons, or special events) and eight types of bias-based bullying among students, with attention to effect modification by relevant demographic characteristics. Students attending schools that offer a wider variety of diversity education opportunities had significantly lower odds of bullying about race, ethnicity, or national origin among boys of color (OR = 0.89, CI: 0.80, 1.00), about sexual orientation for gay, bisexual, and questioning boys (OR = 0.81, CI: 0.67, 0.97), and about disability for boys with a physical health problem (OR = 0.86, CI: 0.76, 0.99). Attending a school with more types of diversity education activities may protect vulnerable students against specific types of bias-based bullying and advance health equity. A diversity education is recommended as a key component of antibullying efforts and policy.


Asunto(s)
Acoso Escolar , Minorías Sexuales y de Género , Adolescente , Bisexualidad , Femenino , Humanos , Masculino , Instituciones Académicas , Estudiantes
20.
Adv Healthc Mater ; 10(22): e2101239, 2021 11.
Artículo en Inglés | MEDLINE | ID: mdl-34467659

RESUMEN

Various lipid-based nanocarriers have been developed for the co-delivery of protein antigens with immunological adjuvants. However, their in vivo potency in vaccine delivery is limited by structural instability, which causes off-target delivery and low cross-presentation efficacies. Recent works employ covalent cross-linking to stabilize the lipid nanostructures, though the immunogenicity and side effects of chemically modified protein antigens and lipids can cause a long-lasting safety issue. Here robust "conjugation-free" multilamellar protein antigen-lipid hybrid nanovesicles (MPLVs) are introduced through the antigen-mediated self-assembly of unilamellar lipid vesicles for the co-delivery of protein antigens and immunologic adjuvants. The nanocarriers coated with monophosphoryl lipid A and hyaluronic acids elicit highly increase antigen-specific immune responses in vitro and in vivo. The MPLVs increase the generation of immunological surface markers and cytokines in mouse-derived bone-marrow dendritic cells compared to soluble antigens with adjuvants. Besides, the vaccination of mice with the MPLVs significantly increase the production of anti-antigen antibody and interferon-gamma via the activation of CD4+ and CD8+ T cells, respectively. These findings suggest that MPLVs can serve as a promising nanovaccine delivery platform for efficient antigen cross-presentation through the efficient co-delivery of protein antigens with adjuvants.


Asunto(s)
Linfocitos T CD8-positivos , Nanopartículas , Adyuvantes Inmunológicos , Animales , Presentación de Antígeno , Antígenos , Células Dendríticas , Lípidos , Ratones , Ratones Endogámicos C57BL , Ovalbúmina
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