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1.
Skin Res Technol ; 30(4): e13714, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38650371

RESUMEN

OBJECTIVE: Platelet-rich plasma (PRP) is recognized as a safe and effective therapy for regenerative skin healing and rejuvenation, utilizing autologous blood enriched with various growth factors. This review aims to assess the efficacy of PRP treatments for skin rejuvenation. METHODS: Keywords such as "platelet-rich plasma," "rejuvenation," "skin aging," and "wrinkles" were queried on Ovid, PubMed, and MEDLINE to identify pertinent studies on PRP treatment for skin rejuvenation. RESULTS: Analysis revealed that PRP treatment led to significant enhancements in multiple facial parameters after one to three sessions. Improvements were noted in skin pore size, texture, wrinkle reduction, pigmented spots, collagen density, hyaluronic acid levels, and protection against ultraviolet damage. Combining PRP with hyaluronic acid demonstrated a synergistic effect, particularly enhancing skin elasticity in patients with lower body mass index and firmness in individuals aged 50s and 60s. Incorporating both physical and biometric data for assessment proved superior to relying solely on physical observations for evaluating subtle skin quality and structural changes. CONCLUSION: This study underscores the efficacy of PRP monotherapy for skin rejuvenation and emphasizes the necessity of standardizing PRP preparation protocols in future investigations. Heightened awareness and advancements in technology have contributed to the emergence of higher-quality, less biased studies supporting PRP as a reliable and safe therapeutic option for skin rejuvenation.


Asunto(s)
Plasma Rico en Plaquetas , Rejuvenecimiento , Envejecimiento de la Piel , Humanos , Rejuvenecimiento/fisiología , Envejecimiento de la Piel/efectos de los fármacos , Envejecimiento de la Piel/fisiología , Ácido Hialurónico , Piel/efectos de la radiación , Técnicas Cosméticas , Persona de Mediana Edad
2.
Skin Res Technol ; 30(6): e13793, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38899793

RESUMEN

BACKGROUND: To evaluate the efficacy and safety of stromal vascular fraction (SVF), platelet rich plasma (PRP), and 1064-nm Q-switched Nd:YAG laser in reducing nanofat treated dark circles and wrinkles under the eyes. METHOD: This study was a single-blinded randomized clinical trial conducted on patients with suborbital darkening under the eyes that randomly divided into control and case groups. In the control group, 15 patients were treated with one session of nanofat injection only, and five patients of each intervention groups received one session of nanofat+SVF injection, nanofat+PRP injection, and nanofat injection+Nd:YAG laser, respectively. Assessments methods were (1) evaluation of the degree of darkness and repair under the eyes by a blinded dermatologist based on clinical photographs, (2) investigating patient satisfaction, (3) using biometric variables for color, thickness, and density of the skin (only 3 months after the treatment), and (4) recording the possible adverse effects. CONCLUSION: In terms of the extent of reduction in the intensity of darkness under the eyes, the combined treatment of nanofat injection together with SVF, PRP, and Nd:YAG laser had a much greater therapeutic effect than nanofat injection alone. In all three groups of combined treatments, patients were 100% satisfied. In terms of biometric variables, amount of changes in colorimeter, complete and dermal thickness, complete and dermal density, between the different groups was statistically significant. The use of combined treatments including nanofat with SVF injection, PRP, and 1064 Q-switched Nd:YAG laser may be more effective than nanofat alone, in reducing infraorbital dark circles and wrinkles.


Asunto(s)
Técnicas Cosméticas , Láseres de Estado Sólido , Plasma Rico en Plaquetas , Envejecimiento de la Piel , Humanos , Femenino , Láseres de Estado Sólido/uso terapéutico , Persona de Mediana Edad , Método Simple Ciego , Adulto , Técnicas Cosméticas/instrumentación , Resultado del Tratamiento , Masculino , Satisfacción del Paciente
3.
Proc Natl Acad Sci U S A ; 117(14): 7622-7632, 2020 04 07.
Artículo en Inglés | MEDLINE | ID: mdl-32193350

RESUMEN

During development, organisms acquire three-dimensional (3D) shapes with important physiological consequences. While basic mechanisms underlying morphogenesis are known in eukaryotes, it is often difficult to manipulate them in vivo. To circumvent this issue, here we present a study of developing Vibrio cholerae biofilms grown on agar substrates in which the spatiotemporal morphological patterns were altered by varying the agar concentration. Expanding biofilms are initially flat but later undergo a mechanical instability and become wrinkled. To gain mechanistic insights into this dynamic pattern-formation process, we developed a model that considers diffusion of nutrients and their uptake by bacteria, bacterial growth/biofilm matrix production, mechanical deformation of both the biofilm and the substrate, and the friction between them. Our model shows quantitative agreement with experimental measurements of biofilm expansion dynamics, and it accurately predicts two distinct spatiotemporal patterns observed in the experiments-the wrinkles initially appear either in the peripheral region and propagate inward (soft substrate/low friction) or in the central region and propagate outward (stiff substrate/high friction). Our results, which establish that nonuniform growth and friction are fundamental determinants of stress anisotropy and hence biofilm morphology, are broadly applicable to bacterial biofilms with similar morphologies and also provide insight into how other bacterial biofilms form distinct wrinkle patterns. We discuss the implications of forming undulated biofilm morphologies, which may enhance the availability of nutrients and signaling molecules and serve as a "bet hedging" strategy.


Asunto(s)
Agar/farmacología , Biopelículas/crecimiento & desarrollo , Vibrio cholerae/fisiología , Anisotropía , Fenómenos Biomecánicos , Fricción , Estrés Mecánico , Propiedades de Superficie
4.
Nano Lett ; 22(6): 2261-2269, 2022 Mar 23.
Artículo en Inglés | MEDLINE | ID: mdl-35234042

RESUMEN

Mechanochromic structural-colored materials have promising applications in various domains. In this Letter, we report three types of reversible mechanochromisms in simple material systems by harnessing mechano-responsive wrinkling dynamics including (i) brightness mechanochromism (BM), (ii) hue change mechanochromism (HCM), and (iii) viewable angle mechanochromism (VAM). Upon stretching, the BM device exhibits almost a constant hue but reduces light brightness due to the postbuckling mechanics-controlled deformation, while the HCM device can change the hue from blue to red with almost constant intensity because of the linear elastic mechanics-controlled deformation. The VAM device shows a constant hue because of the thin film interference effect. However, the viewable angles decrease with increasing applied strain owing to the light scattering of wrinkles. All of the mechanochromic behaviors exhibit good reversibility and durability. We clearly elucidated the underlying mechanisms for different mechanochromisms and demonstrated their potential applications in smart displays, stretchable strain sensors, and antipeeping/anticounterfeiting devices.

5.
Int J Mol Sci ; 24(6)2023 Mar 08.
Artículo en Inglés | MEDLINE | ID: mdl-36982279

RESUMEN

Malignant pleural mesothelioma (MPM) is a rare and aggressive cancer affecting the pleural lining of the lungs. Celastrol (Cela), a pentacyclic triterpenoid, has demonstrated promising therapeutic potential as an antioxidant, anti-inflammatory, neuroprotective agent, and anti-cancer agent. In this study, we developed inhaled surface-modified Cela-loaded poly(lactic-co-glycolic) acid (PLGA) microparticles (Cela MPs) for the treatment of MPM using a double emulsion solvent evaporation method. The optimized Cela MPs exhibited high entrapment efficiency (72.8 ± 6.1%) and possessed a wrinkled surface with a mean geometric diameter of ~2 µm and an aerodynamic diameter of 4.5 ± 0.1 µm, suggesting them to be suitable for pulmonary delivery. A subsequent release study showed an initial burst release up to 59.9 ± 2.9%, followed by sustained release. The therapeutic efficacy of Cela MPs was evaluated against four mesothelioma cell lines, where Cela MP exhibited significant reduction in IC50 values, and blank MPs produced no toxicity to normal cells. Additionally, a 3D-spheroid study was performed where a single dose of Cela MP at 1.0 µM significantly inhibited spheroid growth. Cela MP was also able to retain the antioxidant activity of Cela only while mechanistic studies revealed triggered autophagy and an induction of apoptosis. Therefore, these studies highlight the anti-mesothelioma activity of Cela and demonstrate that Cela MPs are a promising inhalable medicine for MPM treatment.


Asunto(s)
Mesotelioma Maligno , Mesotelioma , Neoplasias Pleurales , Humanos , Copolímero de Ácido Poliláctico-Ácido Poliglicólico , Mesotelioma/tratamiento farmacológico , Mesotelioma/patología , Triterpenos Pentacíclicos/uso terapéutico , Línea Celular Tumoral , Neoplasias Pleurales/patología
6.
Molecules ; 28(4)2023 Feb 10.
Artículo en Inglés | MEDLINE | ID: mdl-36838698

RESUMEN

We investigate the combined effects of surface diffraction and total internal reflection (TIR) in the design of 3-dimensional materials exhibiting distinct structural colour on various facets. We employ mechanical wrinkling to introduce surface diffraction gratings (from the nano to the micron scales) on one face of an elastomeric rectangular parallelepiped-shaped slab and explore the roles, in the perceived colours, of wrinkling pattern, wavelength, the directionality of incident light and observation angles. We propose a simple model that satisfactorily accounts for all experimental observations. Employing polydimethylsiloxane (PDMS), which readily swells in the presence of various liquids and gases, we demonstrate that such multifaceted colours can respond to their environment. By coupling a right angle triangular prism with a surface grating, we demonstrate the straightforward fabrication of a so-called GRISM (GRating + prISM). Finally, using a range of examples, we outline possibilities for a predictive material design using multi-axial wrinkling patterns and more complex polyhedra.


Asunto(s)
Gases , Elasticidad
7.
Small ; 18(42): e2203491, 2022 10.
Artículo en Inglés | MEDLINE | ID: mdl-36047645

RESUMEN

Recent advances in nanolithography, miniaturization, and material science, along with developments in wearable electronics, are pushing the frontiers of sensor technology into the large-scale fabrication of highly sensitive, flexible, stretchable, and multimodal detection systems. Various strategies, including surface engineering, have been developed to control the electrical and mechanical characteristics of sensors. In particular, surface wrinkling provides an effective alternative for improving both the sensing performance and mechanical deformability of flexible and stretchable sensors by releasing interfacial stress, preventing electrical failure, and enlarging surface areas. In this study, recent developments in the fabrication strategies of wrinkling structures for sensor applications are discussed. The fundamental mechanics, geometry control strategies, and various fabricating methods for wrinkling patterns are summarized. Furthermore, the current state of wrinkling approaches and their impacts on the development of various types of sensors, including strain, pressure, temperature, chemical, photodetectors, and multimodal sensors, are reviewed. Finally, existing wrinkling approaches, designs, and sensing strategies are extrapolated into future applications.


Asunto(s)
Dispositivos Electrónicos Vestibles , Electrónica , Temperatura
8.
Planta ; 256(4): 75, 2022 Sep 10.
Artículo en Inglés | MEDLINE | ID: mdl-36087126

RESUMEN

MAIN CONCLUSION: TEM and AFM imaging reveal radial orientations and whorl-like arrangements of cellulose microfibrils near the S1/S2 interface. These are explained by wrinkling during lamellar cell growth. In the most widely accepted model of the ultrastructure of wood cell walls, the cellulose microfibrils are arranged in helical patterns on concentric layers. However, this model is contradicted by a number of transmission electron microscopy (TEM) studies which reveal a radial component to the microfibril orientations in the cell wall. The idea of a radial component of the microfibril directions is not widely accepted, since it cannot easily be explained within the current understanding of lamellar cell growth. To help clarify the microfibril arrangements in wood cell walls, we have investigated various wood cell wall sections using both transmission electron microscopy and atomic force microscopy, and using various imaging and specimen preparation methods. Our investigations confirm that the microfibrils have a radial component near the interface between the S1 and S2 cell wall layers, and also reveal a whorl-like microfibril arrangement at the S1/S2 interface. These whorl-like structures are consistent with cell wall wrinkling during growth, allowing the radial microfibril component to be reconciled with the established models for lamellar cell growth.


Asunto(s)
Microfibrillas , Madera , Pared Celular/ultraestructura , Celulosa/análisis , Microscopía de Fuerza Atómica , Madera/ultraestructura
9.
Lasers Surg Med ; 54(1): 46-53, 2022 01.
Artículo en Inglés | MEDLINE | ID: mdl-34787919

RESUMEN

BACKGROUND: Non-ablative fractional laser is an effective modality for the treatment of periorbital wrinkling, one of the earliest signs of skin aging. Thermo-mechanical fractional injury (TMFI) therapy (Tixel®, Novoxel®, Israel) is an innovative technology that is now being used for facial skin rejuvenation. Our study compares the clinical results, side effects, and downtime profile between TMFI treatment and non-ablative fractional 1565 nm laser (ResurFX®, Lumenis, Israel). METHODS: This was a prospective study of 68 patients (64 women, 4 men) with skin types I-VI in two medical centers (34 from Israel, 34 from the USA) that were randomized to receive either TMFI or NAFL treatment for periorbital wrinkling. Patients received 3-5 treatments, 3-5 weeks apart. Six months after the last treatment, the change in Fitzpatrick Wrinkling Classification System (FWCS) was calculated by three non-involved physicians and compared to pretreatment results. Side effects and downtime profiles were assessed in each group (including VAS pain assessment, time required to refrain from work and social activity, and time required for the resolution of redness, edema, and crusts.) RESULTS: A moderate improvement in periorbital wrinkling was demonstrated in both groups, with an average improvement of 1.6 ± 0.6 in FWCS in the TMFI group and an average improvement of 1.7 ± 0.8 in the NAFL group (p < 0.001). Postprocedural VAS score was 5.86 ± 2.3 in the NAFL group and 4.01 ± 2.6 in the Tixel® group. Approximately 80% of subjects returned to both work and social activities two days postprocedure. Crusts were reported by 52% of patients in the TMFI group, compared to 16% of patients in the NAFL group more than 48 hours postprocedure (p < 0.05). There were no statistically significant differences in the other parameters between the two groups. CONCLUSION: TMFI is an effective and safe modality for the treatment of periorbital wrinkling, with comparable results to the 1565 nm NAFL.


Asunto(s)
Terapia por Láser , Láseres de Estado Sólido , Envejecimiento de la Piel , Femenino , Humanos , Láseres de Estado Sólido/uso terapéutico , Masculino , Estudios Prospectivos , Rejuvenecimiento , Resultado del Tratamiento
10.
Proc Natl Acad Sci U S A ; 116(42): 20875-20880, 2019 10 15.
Artículo en Inglés | MEDLINE | ID: mdl-31570627

RESUMEN

The wrinkling of thin elastic objects provides a means of generating regular patterning at small scales in applications ranging from photovoltaics to microfluidic devices. Static wrinkle patterns are known to be governed by an energetic balance between the object's bending stiffness and an effective substrate stiffness, which may originate from a true substrate stiffness or from tension and curvature along the wrinkles. Here, we investigate dynamic wrinkling induced by the impact of a solid sphere onto an ultrathin polymer sheet floating on water. The vertical deflection of the sheet's center induced by impact draws material radially inward, resulting in an azimuthal compression that is relieved by the wrinkling of the entire sheet. We show that this wrinkling is truly dynamic, exhibiting features that are qualitatively different to those seen in quasistatic wrinkling experiments. Moreover, we show that the wrinkles coarsen dynamically because of the inhibiting effect of the fluid inertia. This dynamic coarsening can be understood heuristically as the result of a dynamic stiffness, which dominates the static stiffnesses reported thus far, and allows control of wrinkle wavelength.

11.
Proc Natl Acad Sci U S A ; 116(34): 16692-16696, 2019 08 20.
Artículo en Inglés | MEDLINE | ID: mdl-31391311

RESUMEN

Inflatable structures offer a path for light deployable structures in medicine, architecture, and aerospace. In this study, we address the challenge of programming the shape of thin sheets of high-stretching modulus cut and sealed along their edges. Internal pressure induces the inflation of the structure into a deployed shape that maximizes its volume. We focus on the shape and nonlinear mechanics of inflated rings and more generally, of any sealed curvilinear path. We rationalize the stress state of the sheet and infer the counterintuitive increase of curvature observed on inflation. In addition to the change of curvature, wrinkles patterns are observed in the region under compression in agreement with our minimal model. We finally develop a simple numerical tool to solve the inverse problem of programming any 2-dimensional (2D) curve on inflation and illustrate the application potential by moving an object along an intricate target path with a simple pressure input.

12.
Nano Lett ; 21(17): 7116-7122, 2021 09 08.
Artículo en Inglés | MEDLINE | ID: mdl-34448588

RESUMEN

Fine control over the mechanical properties of thin sheets underpins transcytosis, cell shape, and morphogenesis. Applying these principles to artificial, liquid-based systems has led to reconfigurable materials for soft robotics, actuation, and chemical synthesis. However, progress is limited by a lack of synthetic two-dimensional membranes that exhibit tunable mechanical properties over a comparable range to that seen in nature. Here, we show that the bending modulus, B, of thin assemblies of nanoparticle surfactants (NPSs) at the oil-water interface can be varied continuously from sub-kBT to 106kBT, by varying the ligands and particles that comprise the NPS. We find extensive departure from continuum behavior, including enormous mechanical anisotropy and a power law relation between B and the buckling spectrum width. Our findings provide a platform for shape-changing liquid devices and motivate new theories for the description of thin-film wrinkling.


Asunto(s)
Nanopartículas , Tensoactivos , Anisotropía
13.
Nano Lett ; 21(3): 1274-1281, 2021 Feb 10.
Artículo en Inglés | MEDLINE | ID: mdl-33523666

RESUMEN

Surface-textured polymer nanocomposite (PNC) films are utilized in many device applications, and therefore understanding the relaxation behavior of such films is important. By extending an in situ wrinkle relaxation method, we observed that the thermal stability of wrinkled PNC films, both above and below the glass transition temperature (Tg), is proportional to a film's nanoparticle (polymer grafted and bare) concentration, with a slope that changes sign at a compensation temperature (Tcomp) that is determined to be in the vicinity of the film's Tg. This provides unambiguous confirmation of entropy-enthalpy compensation (EEC) as a general feature of PNC films, implying that the stability of PNC films changes from being enhanced to becoming diminished by simply passing through this characteristic temperature, a phenomenon having evident practical ramifications. We suggest EEC will also arise in films where residual stresses are associated with the film fabrication process, which is relevant to nanotech device applications.

14.
Angew Chem Int Ed Engl ; 61(31): e202203715, 2022 Aug 01.
Artículo en Inglés | MEDLINE | ID: mdl-35611598

RESUMEN

Ubiquitous surface wrinkling has been well-studied theoretically and experimentally. How to modulate the stress state of a liquid-supported system for the unexploited wrinkling capabilities remains a challenge. Here we report a simple linearly-polarized-light illumination to spatiotemporally trigger ultrasensitive in situ dynamic wrinkling on a floating azo-film. The smart combination of the liquid substrate with photoresponsive azo-moieties leads to the light-induced ultrafast wrinkling evolution, accompanied by unprecedented sequential wrinkling orientation conversion (from polarization-parallel to polarization-perpendicular). The involved different polarization-dependent sequential photo-orientation for azo side chains and azo-grafted main chains of azopolymers is disclosed experimentally for the first time. Meanwhile, programmable dynamic wrinkling with all-optical switchable surface topographies is available, which has wide application potentials in photoresponsive soft photonics.

15.
Macromol Rapid Commun ; 42(7): e2000704, 2021 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-33448071

RESUMEN

As an intriguing characteristic of azobenzene-containing materials (azo-materials), photoinduced changes in mechanical properties (e.g., photosoftening) have stimulated many efforts both theoretically and experimentally. Here a simple yet powerful tool (i.e., a light-associated surface wrinkling-based method) to study the photosoftening effect in azobenzene-polymer (azo-polymer) supramolecular complexes is reported. The photo-induced modulus decrease of supramolecular complex films is deduced by analyzing the change of critical wrinkle wavelength of strain-induced surface wrinkling, in the case of varying experiment parameters. In particular, thanks to the facile modular tunability of the supramolecular system, the photosoftening effect has been systematically investigated as a function of azo-moiety content and the molecular weight of the host polymer. Notably, a photosoftening coefficient that is related to the chemical composition/structure of azo-polymers is introduced, and a simple formula that can quantify the connection of the photosoftening with external irradiation conditions and internal chemical factors of azo-polymers is derived for the first time. The obtained results are of great importance not only to enhance understanding of the photosoftening mechanism, but also to thoroughly apply it in diverse smart fields.


Asunto(s)
Compuestos Azo , Polímeros , Peso Molecular
16.
Nano Lett ; 20(6): 4129-4135, 2020 Jun 10.
Artículo en Inglés | MEDLINE | ID: mdl-32437167

RESUMEN

Reversible and switchable wrinkling surfaces in response to various external stimuli have extensive potential applications. In this Letter, we prepared the reversible wrinkling on poly(dimethylsiloxane) (PDMS) surfaces, responsive to the solvents, by ultraviolet-ozone (UVO) treatment with/without mechanical prestrain. Based on the solvent-responsive wrinkling, three types of optical transparency dynamics were achieved easily in a single and simple film-substrate system, including (I) completely reversible transparency with controlled relaxation time and isotropic light scattering; (II) completely reversible transparency with anisotropic light scattering and tunable diffusion degree; and (III) incompletely reversible transparency. The reversibility and stability of wrinkles can be controlled by tailoring the solvent type, UVO exposure time, and mechanical prestrain. The underlying mechanisms for the three wrinkling dynamics have been clearly elucidated. The extremely simple material system and the facile but efficient technique pave a novel way for realizing versatile optical dynamics for smart displays.

17.
Aesthetic Plast Surg ; 45(2): 690-709, 2021 04.
Artículo en Inglés | MEDLINE | ID: mdl-32445044

RESUMEN

BACKGROUND: Patients often seek aesthetic correction of facial deficiencies (e.g., lines and folds) that are rarely the underlying cause of dissatisfaction with their appearance. Use of a more holistic approach focused on improving the emotional messages of the face (e.g., looking less sad) may improve patient satisfaction with treatment outcomes. The MD Codes™ system was developed to increase clinician success rates by reducing variability in the technical aspects of hyaluronic acid (HA) filler treatment and focusing on addressing unfavorable emotional attributes of the face. METHODS: The MD Codes, or medical codes, represent specific anatomical subunits for injection of HA fillers. Each MD Code includes information regarding the target depth of injection, the proper delivery tool (needle or cannula) and delivery technique (e.g., aliquot, bolus, fanning), and the minimum product volume recommended to achieve visible, reproducible results (active number). During treatment planning, the appropriate MD Codes are selected using algorithms focused on lessening unfavorable facial attributes (a saggy, tired, sad, or angry look) and enhancing positive attributes (an attractive, younger, more contoured, or feminine [soft] or masculine look). RESULTS: Three case studies are presented to illustrate how the MD Codes and their algorithms were used to address sagginess, tiredness, and sadness in two women and one man. CONCLUSIONS: MD Codes provide a universal symbolic language for reducing variability in injection technique. The platform provides user-friendly algorithms to help clinicians increase patient satisfaction by going beyond treatment of lines and folds and to focus on reducing unfavorable facial attributes. LEVEL OF EVIDENCE IV: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .


Asunto(s)
Técnicas Cosméticas , Rellenos Dérmicos , Estética , Femenino , Humanos , Ácido Hialurónico , Masculino , Rejuvenecimiento
18.
Int J Mol Sci ; 22(21)2021 Oct 29.
Artículo en Inglés | MEDLINE | ID: mdl-34769167

RESUMEN

Ultrathin molecular films deposited on a substrate are ubiquitously used in electronics, photonics, and additive manufacturing methods. The nanoscale surface instability of these systems under uniaxial compression is investigated here by molecular dynamics simulations. We focus on deviations from the homogeneous macroscopic behavior due to the discrete, disordered nature of the deformed system, which might have critical importance for applications. The instability, which develops in the elastoplastic regime above a finite critical strain, leads to the growth of unidimensional wrinkling up to strains as large as 0.5. We highlight both the dominant wavelength and the amplitude of the wavy structure. The wavelength is found to scale geometrically with the film length, λ∝L, up to a compressive strain of ε≃0.4 at least, depending on the film length. The onset and growth of the wrinkling under small compression are quite well described by an extended version of the familiar square-root law in the strain ε observed in macroscopic systems. Under large compression (ε≳0.25), we find that the wrinkling amplitude increases while leaving the cross section nearly constant, offering a novel interpretation of the instability with a large amplitude. The contour length of the film topography is not constant under compression, which is in disagreement with the simple accordion model. These findings might be highly relevant for the design of novel and effective wrinkling and buckling patterns and architectures in flexible platforms for electronics and photonics.


Asunto(s)
Nanoestructuras/química , Fuerza Compresiva , Membranas Artificiales , Electricidad Estática , Estrés Mecánico , Propiedades de Superficie
19.
Molecules ; 26(23)2021 Dec 05.
Artículo en Inglés | MEDLINE | ID: mdl-34885963

RESUMEN

Sargassum thunbergii has been traditionally used as an edible and medicinal material in oriental countries. However, the skin-whitening and anti-wrinkling effects of S. thunbergii have not yet been investigated. This study was conducted to establish optimal extraction conditions for the production of bioactive compounds with antioxidant activity as well as skin-whitening and anti-wrinkle effects using ultrasound-assisted extraction (UAE) in S. thunbergii. The extraction time (5.30~18.7 min), extraction temperature (22.4~79.6 °C), and ethanol concentration (0.0~99.5%), which are the main variables of the UAE, were optimized using a central composite design. Quadratic regression equations were derived based on experimental data and showed a high coefficient of determination (R2 > 0.85), demonstrating suitability for prediction. The optimal UAE condition for maximizing all dependent variables, including radical scavenging activity (RSA), tyrosinase inhibitory activity (TIA), and collagenase inhibitory activity (CIA), was identified as an extraction time of 12.0 min, an extraction temperature of 65.2 °C, and ethanol of 53.5%. Under these conditions, the RSA, TIA, and CIA of S. thunbergii extract were 86.5%, 88.3%, and 91.4%, respectively. We also confirmed S. thunbergii extract had inhibitory effects on the mRNA expression of tyrosinase-related protein-1, matrix metalloproteinase-1, and matrix metalloproteinase-9, which are the main genes of melanin synthesis and collagen hydrolysis. Liquid chromatography-tandem mass spectrometry was used to identify the main phenolic compounds in S. thunbergii extract, and caffeic acid was identified as a major peak, demonstrating that high value-added ingredients with skin-whitening and anti-wrinkling effects can be produced from S. thunbergii and used for developing cosmetic materials.


Asunto(s)
Antioxidantes/farmacología , Inhibidores de la Metaloproteinasa de la Matriz/farmacología , Oxidorreductasas/antagonistas & inhibidores , Sargassum/química , Envejecimiento de la Piel/efectos de los fármacos , Animales , Antioxidantes/química , Línea Celular Tumoral , Cosméticos/química , Cosméticos/farmacología , Inhibidores de la Metaloproteinasa de la Matriz/química , Ratones
20.
Proc Natl Acad Sci U S A ; 114(24): 6233-6237, 2017 06 13.
Artículo en Inglés | MEDLINE | ID: mdl-28559335

RESUMEN

Although DNA nanowires have proven useful as a template for fabricating functional nanomaterials and a platform for genetic analysis, their widespread use is still hindered because of limited control over the size, geometry, and alignment of the nanowires. Here, we document the capillarity-induced folding of an initially wrinkled surface and present an approach to the spontaneous formation of aligned DNA nanowires using a template whose surface morphology dynamically changes in response to liquid. In particular, we exploit the familiar wrinkling phenomenon that results from compression of a thin skin on a soft substrate. Once a droplet of liquid solution containing DNA molecules is placed on the wrinkled surface, the liquid from the droplet enters certain wrinkled channels. The capillary forces deform wrinkles containing liquid into sharp folds, whereas the neighboring empty wrinkles are stretched out. In this way, we obtain a periodic array of folded channels that contain liquid solution with DNA molecules. Such an approach serves as a template for the fabrication of arrays of straight or wrinkled DNA nanowires, where their characteristic scales are robustly tunable with the physical properties of liquid and the mechanical and geometrical properties of the elastic system.

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