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1.
J Mater Chem B ; 12(29): 7076-7089, 2024 Jul 24.
Article in English | MEDLINE | ID: mdl-38817163

ABSTRACT

A series of amphiphilic block copolymer (BCP) micelles based on poly(dimethylsiloxane) (PDMS) and poly(ethylene glycol) (PEG) were synthesized by a one-step reaction in the presence of tris(pentafluorophenyl)borane (BCF) as a catalyst. The structural composition of PDMS-b-PEG (PR11) and PEG-b-PDMS-b-PEG (PR12) was corroborated by FTIR, 29Si NMR, and TGA. The BCPs were assembled in an aqueous solution, obtaining micelles between 57 and 87 nm in size. PR11 exhibited a higher (2.0 g L-1) critical micelle concentration (CMC) than PR12 (1.5 g L-1) due to the short chain length. The synthesized nano micelles were used to encapsulate curcumin, which is one of three compounds of turmeric plant 'Curcuma longa' with significant biological activities, including antioxidant, chemoprotective, antibacterial, anti-inflammatory, antiviral, and anti-depressant properties. The encapsulation efficiency of curcumin was 60% for PR11 and 45% for PR12. Regarding the release study, PR11 delivered 53% curcumin after five days under acidic conditions (pH of 1.2) compared to 43% at a pH of 7.4. The degradation products of curcumin were observed under basic conditions and were more stable at acidic pH. In both situations, the release process is carried out by breaking the silyl-ether bond, allowing the release of curcumin. PR11 showed prolonged release times, so it could be used to reduce ingestion times and simultaneously work as a nanocarrier for other hydrophobic drugs.


Subject(s)
Curcumin , Dimethylpolysiloxanes , Micelles , Polyethylene Glycols , Curcumin/chemistry , Curcumin/pharmacology , Dimethylpolysiloxanes/chemistry , Polyethylene Glycols/chemistry , Particle Size , Boranes/chemistry , Drug Liberation , Drug Carriers/chemistry , Drug Carriers/chemical synthesis , Surface-Active Agents/chemistry , Surface-Active Agents/chemical synthesis
2.
Curr Microbiol ; 80(8): 256, 2023 Jun 25.
Article in English | MEDLINE | ID: mdl-37357232

ABSTRACT

Different strategies were tested to reduce biofilm formation of the model marine bacteria Cobetia marina and Marinobacter hydrocarbonoclasticus on cross-linked polydimethylsiloxane (PDMS) coated aluminum and cellulose acetate surfaces modified by addition of multi-walled carbon nanotubes (MWCNT) or exposure of the surfaces to bromine vapors in the presence and absence of UV irradiation. The three surface modifications explored led to important reductions in biofilm formation for the two marine bacteria, up to 30% in the case of exposure to Br2(g). Biofouling reduction could be correlated to surface properties in all cases through the introduction of a quantitative theoretical model based on an effective roughness parameter, Raeff, that accounted for the different morphological changes observed. The model considers the possibility of bacterial inclusion into large surface wells, as observed by AFM in the case of Br2(g) + UV light treatment. In addition, a linear relationship was observed between biofouling reduction and the Raeff effective roughness parameter.


Subject(s)
Biofouling , Nanotubes, Carbon , Biofilms , Dimethylpolysiloxanes , Bacteria
3.
J Chromatogr A ; 1699: 463998, 2023 Jun 21.
Article in English | MEDLINE | ID: mdl-37116299

ABSTRACT

Terpenes and terpenoids are the principal responsible for the aroma of Cannabis, playing an important role in the interaction with the environment. Analytical determination of these compounds can be done by headspace coupled to solid phase micro-extraction (HS-SPME) and then injected in a gas chromatograph. In the present study, we determined distribution constants between gas and polydimetylsiloxane (PDMS), a conventional SPME liquid phase, at three temperatures between 303.15 and 343.15 K for major Cannabis terpenes and terpenoids employing a method based in gas chromatography using four capillary columns for monoterpenes and five columns for sesquiterpenes. In addition, van't Hoff regressions (logKfg vs T-1) were obtained in order to estimate logKfg at 298.15 K aiming to compare with bibliographic values (experimental or estimated ones). An excellent agreement was found between them. The method, based on chromatographic theory is robust and relatively simple. It is expected that the herein obtained data could be useful for selecting SPME fiber type and dimensions, estimating extraction efficiencies, as well as to develop prediction models and validate them.


Subject(s)
Cannabis , Terpenes , Terpenes/analysis , Gas Chromatography-Mass Spectrometry/methods , Solid Phase Microextraction/methods , Chromatography, Gas , Dimethylpolysiloxanes/chemistry
4.
Sensors (Basel) ; 23(2)2023 Jan 15.
Article in English | MEDLINE | ID: mdl-36679789

ABSTRACT

This paper presents the development and application of a multiplexed intensity variation-based sensor system for multiplane shape reconstruction. The sensor is based on a polymer optical fiber (POF) with sequential lateral sections coupled with a flexible light-emitting diode (LED) belt. The optical source modulation enables the development of 30 independent sensors using one photodetector, where the sensor system is embedded in polydimethylsiloxane (PDMS) resin in two configurations. Configuration 1 is a continuous PDMS layer applied in the interface between the flexible LED belt and the POF, whereas Configuration 2 comprises a 20 mm length PDMS layer only on each lateral section and LED region. The finite element method (FEM) is employed for the strain distribution evaluation in different conditions, including the strain distribution on the sensor system subjected to momentums in roll, pitch and yaw conditions. The experimental results of pressure application at 30 regions for each configuration indicated a higher sensitivity of Configuration 1 (83.58 a.u./kPa) when compared with Configuration 2 (40.06 a.u./kPa). However, Configuration 2 presented the smallest cross-sensitivity between sequential sensors (0.94 a.u./kPa against 45.5 a.u./kPa of Configuration 1). Then, the possibility of real-time loading condition monitoring and shape reconstruction is evaluated using Configuration 1 subjected to momentums in roll, pitch and yaw, as well as mechanical waves applied on the sensor structure. The strain distribution on the sensor presented the same pattern as the one obtained in the simulations, and the real-time response of each sensor was obtained for each case. In addition, the possibility of real-time loading condition estimation is analyzed using the k-means algorithm (an unsupervised machine learning approach) for the clusterization of data regarding the loading condition. The comparison between the predicted results and the real ones shows a 90.55% success rate. Thus, the proposed sensor device is a feasible alternative for integrated sensing in movement analysis, structural health monitoring submitted to dynamic loading and robotics for the assessment of the robot structure.


Subject(s)
Optical Fibers , Robotics , Elastomers , Polymers , Dimethylpolysiloxanes/chemistry
5.
Cells ; 11(19)2022 10 01.
Article in English | MEDLINE | ID: mdl-36231063

ABSTRACT

This systematic review aimed to analyze the development and functionality of microfluidic concentration gradient generators (CGGs) for toxicological evaluation of different biological organisms. We searched articles using the keywords: concentration gradient generator, toxicity, and microfluidic device. Only 33 of the 352 articles found were included and examined regarding the fabrication of the microdevices, the characteristics of the CGG, the biological model, and the desired results. The main fabrication method was soft lithography, using polydimethylsiloxane (PDMS) material (91%) and SU-8 as the mold (58.3%). New technologies were applied to minimize shear and bubble problems, reduce costs, and accelerate prototyping. The Christmas tree CGG design and its variations were the most reported in the studies, as well as the convective method of generation (61%). Biological models included bacteria and nematodes for antibiotic screening, microalgae for pollutant toxicity, tumor and normal cells for, primarily, chemotherapy screening, and Zebrafish embryos for drug and metal developmental toxicity. The toxic effects of each concentration generated were evaluated mostly with imaging and microscopy techniques. This study showed an advantage of CGGs over other techniques and their applicability for several biological models. Even with soft lithography, PDMS, and Christmas tree being more popular in their respective categories, current studies aim to apply new technologies and intricate architectures to improve testing effectiveness and reduce common microfluidics problems, allowing for high applicability of toxicity tests in different medical and environmental models.


Subject(s)
Environmental Pollutants , Lab-On-A-Chip Devices , Animals , Anti-Bacterial Agents , Dimethylpolysiloxanes , Zebrafish
6.
Cochrane Database Syst Rev ; 9: CD011642, 2022 09 26.
Article in English | MEDLINE | ID: mdl-36161591

ABSTRACT

BACKGROUND: Hypertrophic and keloid scars are common skin conditions resulting from abnormal wound healing. They can cause itching, pain and have a negative physical and psychological impact on patients' lives. Different approaches are used aiming to improve these scars, including intralesional corticosteroids, surgery and more recently, laser therapy. Since laser therapy is expensive and may have adverse effects, it is critical to evaluate the potential benefits and harms of this therapy for treating hypertrophic and keloid scars. OBJECTIVES: To assess the effects of laser therapy for treating hypertrophic and keloid scars. SEARCH METHODS: In March 2021 we searched the Cochrane Wounds Specialised Register, CENTRAL, MEDLINE, Embase, CINAHL EBSCO Plus and LILACS. To identify additional studies, we also searched clinical trials registries for ongoing and unpublished studies, and scanned reference lists of relevant included studies as well as reviews, meta-analyses, and health technology reports. There were no restrictions with respect to language, date of publication, or study setting. SELECTION CRITERIA: We included randomised controlled trials (RCTs) for treating hypertrophic or keloid scars (or both), comparing laser therapy with placebo, no intervention or another intervention. DATA COLLECTION AND ANALYSIS: Two review authors independently selected studies, extracted the data, assessed the risk of bias of included studies and carried out GRADE assessments to assess the certainty of evidence. A third review author arbitrated if there were disagreements. MAIN RESULTS: We included 15 RCTs, involving 604 participants (children and adults) with study sample sizes ranging from 10 to 120 participants (mean 40.27). Where studies randomised different parts of the same scar, each scar segment was the unit of analysis (906 scar segments). The length of participant follow-up varied from 12 weeks to 12 months. All included trials had a high risk of bias for at least one domain: all studies were deemed at high risk of bias due to lack of blinding of participants and personnel. The variability of intervention types, controls, follow-up periods and limitations with report data meant we pooled data for one comparison (and only two outcomes within this). Several review secondary outcomes - cosmesis, tolerance, preference for different modes of treatment, adherence, and change in quality of life - were not reported in any of the included studies. Laser versus no treatment: We found low-certainty evidence suggesting there may be more hypertrophic and keloid scar improvement (that is scars are less severe) in 585-nm pulsed-dye laser (PDL) -treated scars compared with no treatment (risk ratio (RR) 1.96; 95% confidence interval (CI): 1.11 to 3.45; two studies, 60 scar segments). It is unclear whether non-ablative fractional laser (NAFL) impacts on hypertrophic scar severity when compared with no treatment (very low-certainty evidence). It is unclear whether fractional carbon dioxide (CO2) laser impacts on hypertrophic and keloid scar severity compared with no treatment (very low-certainty evidence). Eight studies reported treatment-related adverse effects but did not provide enough data for further analyses. Laser versus other treatments: We are uncertain whether treatment with 585-nm PDL impacts on hypertrophic and keloid scar severity compared with intralesional corticosteroid triamcinolone acetonide (TAC), intralesional Fluorouracil (5-FU) or combined use of TAC plus 5-FU (very low-certainty evidence). It is also uncertain whether erbium laser impacts on hypertrophic scar severity when compared with TAC (very low-certainty evidence). Other comparisons included 585-nm PDL versus silicone gel sheeting, fractional CO2 laser versus TAC and fractional CO2 laser versus verapamil. However, the authors did not report enough data regarding the severity of scars to compare the interventions. As only very low-certainty evidence is available on treatment-related adverse effects, including pain, charring (skin burning so that the surface becomes blackened), telangiectasia (a condition in which tiny blood vessels cause thread-like red lines on the skin), skin atrophy (skin thinning), purpuric discolorations, hypopigmentation (skin colour becomes lighter), and erosion (loss of part of the top layer of skin, leaving a denuded surface) secondary to blistering, we are not able to draw conclusions as to how these treatments compare. Laser plus other treatment versus other treatment: It is unclear whether 585-nm PDL plus TAC plus 5-FU leads to a higher percentage of good to excellent improvement in hypertrophic and keloid scar severity compared with TAC plus 5-FU, as the certainty of evidence has been assessed as very low. Due to very low-certainty evidence, it is also uncertain whether CO2 laser plus TAC impacts on keloid scar severity compared with cryosurgery plus TAC. The evidence is also very uncertain about the effect of neodymium-doped yttrium aluminium garnet (Nd:YAG) laser plus intralesional corticosteroid diprospan plus 5-FU on scar severity compared with diprospan plus 5-FU and about the effect of helium-neon (He-Ne) laser plus decamethyltetrasiloxane, polydimethylsiloxane and cyclopentasiloxane cream on scar severity compared with decamethyltetrasiloxane, polydimethylsiloxane and cyclopentasiloxane cream. Only very low-certainty evidence is available on treatment-related adverse effects, including pain, atrophy, erythema, telangiectasia, hypopigmentation, regrowth, hyperpigmentation (skin colour becomes darker), and depigmentation (loss of colour from the skin). Therefore, we are not able to draw conclusions as to how these treatments compare.  AUTHORS' CONCLUSIONS: There is insufficient evidence to support or refute the effectiveness of laser therapy for treating hypertrophic and keloid scars. The available information is also insufficient to perform a more accurate analysis on treatment-related adverse effects related to laser therapy. Due to the heterogeneity of the studies, conflicting results, study design issues and small sample sizes, further high-quality trials, with validated scales and core outcome sets should be developed. These trials should take into consideration the consumers' opinion and values, the need for long-term follow-up and the necessity of reporting the rate of recurrence of scars to determine whether lasers may achieve superior results when compared with other therapies for treating hypertrophic and keloid scars.


Subject(s)
Cicatrix, Hypertrophic , Hypopigmentation , Keloid , Laser Therapy , Telangiectasis , Adrenal Cortex Hormones/therapeutic use , Adult , Aluminum , Atrophy , Carbon Dioxide , Child , Cicatrix, Hypertrophic/etiology , Cicatrix, Hypertrophic/radiotherapy , Dimethylpolysiloxanes , Erbium , Fluorouracil , Helium , Humans , Hypertrophy , Hypopigmentation/etiology , Keloid/etiology , Keloid/radiotherapy , Laser Therapy/adverse effects , Neodymium , Neon , Pain/etiology , Silicone Gels , Telangiectasis/etiology , Triamcinolone Acetonide , Verapamil , Wound Healing , Yttrium
7.
Molecules ; 27(15)2022 Aug 04.
Article in English | MEDLINE | ID: mdl-35956905

ABSTRACT

Grumixama (Eugenia brasiliensis Lam.) is a native fruit of the Brazilian Atlantic Forest, belonging to the Myrtaceae family, which designatesthe most significant number of species with food potential. It stands out due to its phytochemical characteristics because of the presence of polyphenols and volatile organic compounds. Volatile compounds are substances released by foods that give off an aroma and influence flavor. Solid-phase microextraction is a technique that allows for low-cost, fast, and solvent-free extraction, has an affinity for numerous analytes, and is easily coupled to gas chromatography. The objectives of this work were to evaluate the efficiency of different fibers of SPME (solid-phase microextraction) in the extraction of volatile organic compounds from grumixama pulp; optimize a method for extraction time, temperature, and sample weight; and to determine the characteristic volatile profile of this fruit. For the extraction of volatile compounds, three fibers of different polarities were used: polar polyacrylate (PA) fibers, divinylbenzene/carboxyne/polydimethylsiloxane (DVB/CAR/PDMS) semipolar fibers, and polydimethylsiloxane/divinylbenzene (PDMS/DVB). Fourteen volatile organic compounds (VOCs) were identified by DVB/CAR/PDMS, six by PA, and seven by PDMS/DVB through solid-phase microextraction in the headspace mode (SPME-HS). Considering the total number of compounds identified, regardless of the fiber used, and the optimization of the method, Eugenia brasiliensis presented sesquiterpene fractions (85.7%, 83.3%, and 85.7% of total VOCs) higher than the monoterpene fractions (14.3%, 16.7%, and 14.3%) for DVB/CAR/PDMS, PA, and PDMS/DVB, respectively in its composition. In addition, it was possible to verify that the fiber DVB/CAR/PDMS presented a better efficiency due to the larger chromatographic area observed when the grumixama pulp was subjected to conditions of 75 °C, 2.0 g, and an adsorption time of 20 min.


Subject(s)
Eugenia , Volatile Organic Compounds , Dimethylpolysiloxanes/chemistry , Fruit/chemistry , Gas Chromatography-Mass Spectrometry/methods , Solid Phase Microextraction/methods , Volatile Organic Compounds/analysis
8.
Molecules ; 26(17)2021 Sep 04.
Article in English | MEDLINE | ID: mdl-34500809

ABSTRACT

We demonstrate a novel structure based on smart carbon nanocomposites intended for fabricating laser-triggered drug delivery devices (DDDs). The performance of the devices relies on nanocomposites' photothermal effects that are based on polydimethylsiloxane (PDMS) with carbon nanoparticles (CNPs). Upon evaluating the main features of the nanocomposites through physicochemical and photomechanical characterizations, we identified the main photomechanical features to be considered for selecting a nanocomposite for the DDDs. The capabilities of the PDMS/CNPs prototypes for drug delivery were tested using rhodamine-B (Rh-B) as a marker solution, allowing for visualizing and quantifying the release of the marker contained within the device. Our results showed that the DDDs readily expel the Rh-B from the reservoir upon laser irradiation and the amount of released Rh-B depends on the exposure time. Additionally, we identified two main Rh-B release mechanisms, the first one is based on the device elastic deformation and the second one is based on bubble generation and its expansion into the device. Both mechanisms were further elucidated through numerical simulations and compared with the experimental results. These promising results demonstrate that an inexpensive nanocomposite such as PDMS/CNPs can serve as a foundation for novel DDDs with spatial and temporal release control through laser irradiation.


Subject(s)
Drug Carriers/chemistry , Nanocomposites/chemistry , Smart Materials/chemistry , Carbon/chemistry , Dimethylpolysiloxanes/chemistry , Drug Carriers/radiation effects , Elasticity , Lasers , Light , Mechanical Phenomena , Nanocomposites/radiation effects , Rhodamines/chemistry , Smart Materials/radiation effects
9.
Talanta ; 233: 122514, 2021 Oct 01.
Article in English | MEDLINE | ID: mdl-34215129

ABSTRACT

Channel-based microfluidic devices integrating the separation step and detection system are key factors to expand microanalysis application. However, these devices still depend on macroscale external equipment for pre-treatment of the sample, separation, or detection. The integration of all steps in only one stage is critical to improving feasibility. Herein, we use a low-cost protocol to solve part of the challenge by designing a dual-mode system onto single polydimethylsiloxane (PDMS)-based platform - overall dimensions of 65 mm length × 20 mm width × 14 mm height and the inner diameter of 297±10 µm height × 605±19 µm width - for column-free separation and simultaneous detection. As a proof-of-concept, we used this all-in-one PDMS platform to separate - without the packet-based phase - and determine salicylic acid (SA) and caffeine (CAF) with a detection limit of 0.20 and 0.18 µmol L-1 and quantification limit of 0.70 and 0.60 µmol L-1 for SA and CAF, respectively. We separated the mixture using forced convection into a chemically treated microchannel while detecting the analytes in amperometric mode. Here, we report new insights into how integrating analytes separation and further electroanalysis into a single miniaturized device.


Subject(s)
Dimethylpolysiloxanes , Lab-On-A-Chip Devices
10.
Ultrason Sonochem ; 74: 105556, 2021 Jun.
Article in English | MEDLINE | ID: mdl-33915482

ABSTRACT

The use of ultrasound to generate mini-emulsions (50 nm to 1 µm in diameter) and nanoemulsions (mean droplet diameter < 200 nm) is of great relevance in drug delivery, particle synthesis and cosmetic and food industries. Therefore, it is desirable to develop new strategies to obtain new formulations faster and with less reagent consumption. Here, we present a polydimethylsiloxane (PDMS)-based microfluidic device that generates oil-in-water or water-in-oil mini-emulsions in continuous flow employing ultrasound as the driving force. A Langevin piezoelectric attached to the same glass slide as the microdevice provides enough power to create mini-emulsions in a single cycle and without reagents pre-homogenization. By introducing independently four different fluids into the microfluidic platform, it is possible to gradually modify the composition of oil, water and two different surfactants, to determine the most favorable formulation for minimizing droplet diameter and polydispersity, employing less than 500 µL of reagents. It was found that cavitation bubbles are the most important mechanism underlying emulsions formation in the microchannels and that degassing of the aqueous phase before its introduction to the device can be an important factor for reduction of droplet polydispersity. This idea is demonstrated by synthetizing solid polymeric particles with a narrow size distribution starting from a mini-emulsion produced by the device.


Subject(s)
Hydrodynamics , Lab-On-A-Chip Devices , Ultrasonic Waves , Dimethylpolysiloxanes/chemistry , Emulsions , Nylons/chemistry , Oils/chemistry , Surface-Active Agents/chemistry , Water/chemistry
11.
J Biomater Appl ; 36(2): 252-263, 2021 08.
Article in English | MEDLINE | ID: mdl-33906516

ABSTRACT

Given the global panorama of demands in the health area, the development of biomaterials becomes irreducible for the maintenance and/or improvement in the quality of life of the human being. Aiming to reduce the impacts related to infections in the healing processes of the dermal structure, the present work proposes the development of polydimethylsiloxane (PDMS) based membranes with the incorporated polyhexamethylenebiguanide (PHMB) antimicrobial agent. In the present study, the antimicrobial and antibiofilm properties of polydimethylsiloxane (PDMS) films incorporated with 0.1, 0.3, and 0.5% (w/w) of polyhexamethylene biguanide (PHMB) were evaluated, aiming the development of a protective biomaterial that avoids cutaneous infections from the autochthonous and allochthonous microbiota. The disk diffusion of PHMB-loaded PDMS has shown the growth inhibition of Escherichia coli (ATCC 9637), Pseudomonas aeruginosa (ATCC 27953), Acinetobacter baumannii (ATCC 19606), Staphylococcus aureus (ATCC 6538), Staphylococcus epidermidis (ATCC 12228), Streptococcus pyogenes (ATCC 19615), Bacillus subtilis (ATCC 6633) and also yeast-like fungi Candida albicans, all microorganisms found on the epidermal surface. Likewise, the present study demonstrated low cytotoxicity of the PHMB-loaded PDMS on HaCaT and L929 cells at lower concentrations (0.1% w/w), indicating the possibility of using the developed material as a dressing for wounds, burns, and post-surgical procedures.


Subject(s)
Anti-Infective Agents/chemistry , Dimethylpolysiloxanes/chemistry , Guanidines/chemistry , Animals , Anti-Infective Agents/metabolism , Anti-Infective Agents/pharmacology , Biocompatible Materials/chemistry , Biocompatible Materials/pharmacology , Biofilms/drug effects , Candida albicans/drug effects , Candida albicans/physiology , Cell Line , Cell Survival/drug effects , Escherichia coli/drug effects , Escherichia coli/physiology , Guanidines/metabolism , Guanidines/pharmacology , Humans , Mice , Microbial Sensitivity Tests , Staphylococcus aureus/drug effects , Staphylococcus aureus/physiology
12.
Acta Biomater ; 121: 339-348, 2021 02.
Article in English | MEDLINE | ID: mdl-33271355

ABSTRACT

Silicones (i.e. crosslinked poly(dimethylsiloxane), PDMS) are commonly used material for microfluidic device fabrication. Nonetheless, due to the uncontrollable absorption of small hydrophobic molecules (<1 kDa) into the bulk, its applicability to cell-based drug assays and sensing applications has been limited. Here, we demonstrate the use of substrates made of silicones bulk modified with a poly(ethylene oxide) silane amphiphile (PEO-SA) to reduce hydrophobic small molecule sequestration for cell-based assays. Modified silicone substrates were generated with concentrations of 2 wt.%, 9 wt.% and, 14 wt.% PEO-SA. Incorporation of PEO-SA into the silicone bulk was assessed by FTIR analysis in addition to water contact angle analysis to evaluate surface hydrophobicity. Cell toxicity, absorption of small hydrophobic drugs, and cell response to hydrophobic molecules were also evaluated. Results showed that the incorporation of the PEO-SA into the silicone led to a reduction in water contact angle from 114° to as low as 16° that was stable for at least three months. The modified silicones showed viability values above 85% for NIH-3T3, MCF7, MDA-MB-468, and MDA-MB-231 cell lines. A drug response assay using tamoxifen and the MCF7 cell line showed full recovery of cell toxicity response when exposed to PDMS modified with 9 wt.% or 14 wt.% PEO-SA compared to tissue culture plastic. Therefore, our study supports the use of PEO-SA at concentrations of 9 wt.% or higher for enhanced surface wettability and reduced absorption of small hydrophobic molecules in PDMS-based platforms.


Subject(s)
Dimethylpolysiloxanes , Silicones , Hydrophobic and Hydrophilic Interactions , Polyethylene Glycols , Water , Wettability
13.
Food Chem ; 328: 127109, 2020 Oct 30.
Article in English | MEDLINE | ID: mdl-32454261

ABSTRACT

Feijoa is a subtropical bush of the Myrtaceae family. It has unique fruit with organoleptic properties that make it an exotic fruit. Head space solid phase microextraction (HS-SPME) with a 65 µm divinylbenzene/polydimethylsiloxane (DVB/PDMS) fiber and gas chromatography coupled to mass spectrophotometry (GC-MS) was used to study the volatile fraction of feijoa fruit cultured in Caldas, Colombia. The profile analyzed included 134 volatile organic compounds (VOCs). 127 VOCs were classified based on the functional group using the spectral and structural networks correlation analysis. Methyl, ethyl and (Z)-3-hexenyl benzoate with 50% of the volatile composition, were the main compounds. Biosynthesis of the volatilome of feijoa fruit was associated with five main metabolic pathways. This study represents the first analysis of feijoa fruit commercialized in the region. This is an innovator view in elucidation of metabolic pathways that represent the biochemistry of the aroma of this fruit.


Subject(s)
Feijoa/chemistry , Gas Chromatography-Mass Spectrometry/methods , Solid Phase Microextraction/methods , Volatile Organic Compounds/analysis , Colombia , Dimethylpolysiloxanes/chemistry , Feijoa/metabolism , Food Analysis/methods , Fruit/chemistry , Fruit/metabolism , Odorants/analysis , Polyvinyls/chemistry
14.
Sci Rep ; 10(1): 7173, 2020 04 28.
Article in English | MEDLINE | ID: mdl-32346066

ABSTRACT

To evaluate the effect of GuttaFlow bioseal (GFB) and MTA Fillapex (MTAF) in comparison with Endofill (EF) in the subcutaneous tissue. Polyethylene tubes with GFB, MTAF, EF or empty tubes (control group; CG) were implanted into subcutaneous of rats. After 7, 15, 30 and 60 days, the capsule thickness, inflammatory reaction, interleukin-6 (IL-6), vascular endothelial growth factor (VEGF), caspase-3, TUNEL-positive cells, von Kossa and ultrastructural features were evaluated. The data were statistically analyzed (p ≤ 0.05). At all periods, the number of IL-6- and VEGF-immunolabelled cells, and capsule thickness were lower in GFB than MTAF, which was lower than EF (p < 0.0001). At 60 days, the number of inflammatory cells was similar in GFB and MTAF (p = 0.58). Significant differences in the number of TUNEL- and caspase-3-positive cells were not observed among GFB, MTAF and CG whereas the highest values were found in EF specimens. The EF specimens exhibited several cells with condensed chromatin, typical of apoptosis. von Kossa-positive and birefringent structures were only observed in GFB and MTAF, suggesting the presence of calcite crystals. Taken together, these results show that cellular and structural damage induced by GFB and MTAF sealers were recovery over time. Moreover, these sealers express bioactive potential in subcutaneous tissue.


Subject(s)
Apoptosis/drug effects , Dimethylpolysiloxanes/pharmacology , Gutta-Percha/pharmacology , Root Canal Filling Materials/pharmacology , Subcutaneous Tissue/immunology , Animals , Apoptosis/immunology , Caspase 3/immunology , Drug Combinations , Inflammation/immunology , Inflammation/pathology , Interleukin-6/immunology , Male , Rats , Rats, Sprague-Dawley , Subcutaneous Tissue/pathology , Vascular Endothelial Growth Factor A/immunology
15.
Braz. j. infect. dis ; Braz. j. infect. dis;24(2): 170-177, Mar.-Apr. 2020. graf
Article in English | LILACS, Coleciona SUS | ID: biblio-1132432

ABSTRACT

ABSTRACT Epidermal parasitic skin diseases encompass scabies, pediculosis, cutaneous larva migrans, myiasis, and tungiasis. Tungiasis is probably the most neglected of all Neglected Tropical Diseases (NTD). It occurs in South America, the Caribbean and Sub-Saharan Africa and affects marginalized populations where people live in extreme poverty. In endemic communities the prevalence can be up to 30% in general population and 85% in children. Over time, chronic pathology develops characterized by hyperkeratosis, edema around the nail rim, fissures, ulcers, deformation and loss of nails. This leads to a pattern of disabilities, eventually resulting in impairment of mobility.Dimeticones are a family of silicon oils with a potential to kill parasites located on top or inside the epidermis by a physical mode of action. They are considered the treatment of choice for pediculosis capitis and pediculosis pubis. With regard to tungiasis, the so called rear abdominal cone of the parasites has been identified as a target for treatment with dimeticones. NYDA®, a mixture of two dimeticones with different viscosity, is the only dimeticone product for which data on the mode of action, efficacy and safety with regard to tungiasis exists. The product has been shown highly effective against embedded sand fleas, even in very intense infection with more than 500 parasites situated on top of each other. A randomized controlled trial showed that seven days after a targeted application of NYDA® 97% (95% CI 94-99%) of the embedded sand fleas had lost all signs of viability.Comprehensive toxicological investigations on the dimeticones contained in NYDA® showed that there is practically no risk of embryotoxicity, fetotoxicity, teratogenicity, and other toxicity. The safety of dimeticones was also demonstrated in clinical trials with a total of 106 participants with tungiasis, in which not a single adverse event was observed.


Subject(s)
Animals , Child , Female , Humans , Male , Dimethylpolysiloxanes/therapeutic use , Tungiasis/drug therapy , Neglected Diseases/drug therapy , Skin Diseases, Parasitic/parasitology , Skin Diseases, Parasitic/drug therapy , Clinical Trials as Topic , Neglected Diseases/parasitology
16.
Braz J Infect Dis ; 24(2): 170-177, 2020.
Article in English | MEDLINE | ID: mdl-32105621

ABSTRACT

Epidermal parasitic skin diseases encompass scabies, pediculosis, cutaneous larva migrans, myiasis, and tungiasis. Tungiasis is probably the most neglected of all Neglected Tropical Diseases (NTD). It occurs in South America, the Caribbean and Sub-Saharan Africa and affects marginalized populations where people live in extreme poverty. In endemic communities the prevalence can be up to 30% in general population and 85% in children. Over time, chronic pathology develops characterized by hyperkeratosis, edema around the nail rim, fissures, ulcers, deformation and loss of nails. This leads to a pattern of disabilities, eventually resulting in impairment of mobility. Dimeticones are a family of silicon oils with a potential to kill parasites located on top or inside the epidermis by a physical mode of action. They are considered the treatment of choice for pediculosis capitis and pediculosis pubis. With regard to tungiasis, the so called rear abdominal cone of the parasites has been identified as a target for treatment with dimeticones. NYDA®, a mixture of two dimeticones with different viscosity, is the only dimeticone product for which data on the mode of action, efficacy and safety with regard to tungiasis exists. The product has been shown highly effective against embedded sand fleas, even in very intense infection with more than 500 parasites situated on top of each other. A randomized controlled trial showed that seven days after a targeted application of NYDA® 97% (95% CI 94-99%) of the embedded sand fleas had lost all signs of viability. Comprehensive toxicological investigations on the dimeticones contained in NYDA® showed that there is practically no risk of embryotoxicity, fetotoxicity, teratogenicity, and other toxicity. The safety of dimeticones was also demonstrated in clinical trials with a total of 106 participants with tungiasis, in which not a single adverse event was observed.


Subject(s)
Dimethylpolysiloxanes/therapeutic use , Neglected Diseases/drug therapy , Tungiasis/drug therapy , Animals , Child , Clinical Trials as Topic , Female , Humans , Male , Neglected Diseases/parasitology , Skin Diseases, Parasitic/drug therapy , Skin Diseases, Parasitic/parasitology
17.
Int Braz J Urol ; 45(5): 989-998, 2019.
Article in English | MEDLINE | ID: mdl-31626522

ABSTRACT

OBJECTIVE: To evaluate the subjective and objective outcomes of MacroplastiqueR (MPQ) in women with stress urinary incontinence (SUI) secondary to intrinsic sphincter deficiency (ISD). MATERIALS AND METHODS: Following Institutional Review Board (IRB) approval, charts of non-neurogenic women with SUI secondary to ISD who underwent MPQ injection and had 6 months minimum follow-up were reviewed from a prospectively maintained database. Patients were divided into 3 groups: Naive (Group I), Prior Anti-Incontinence Surgery (Group II), and combined Prior Bulking Agent and Anti-Incontinence Surgery (Group III). Data collected included SUI self-report, Urogenital Distress Inventory (UDI-6) Question 3, and VAS Quality of Life (QoL) Questionnaire scores at baseline and in follow-up. Three-dimensional ultrasound (3DUS) evaluated volume/confi guration of MPQ. Success was defi ned after the last MPQ injection as a UDI-6 Question 3 score of 0 (dry) or 1, and no reoperation for SUI. RESULTS: From 2011-2017, 106 of 142 women met study criteria. At a median follow-up of 20 months (mean=26 months; range: 6-71), success rate was 41% for Group I, 40% for Group II, and 65% for Group III (p = 0.22). QoL scores were signifi cantly improved over baseline in all groups. There was no signifi cant difference in clinical outcome between the asymmetrical and symmetrical group on 3DUS. The completely dry rate was highest in Group III at 29%, compared to 4% for Group I and 15% for Group II (p = 0.05). CONCLUSION: MacroplastiqueR improved subjective and objective outcome measures for SUI secondary to ISD as both a primary and secondary treatment option in women.


Subject(s)
Dimethylpolysiloxanes/therapeutic use , Urethral Diseases/complications , Urinary Incontinence, Stress/etiology , Urinary Incontinence, Stress/surgery , Adult , Aged , Aged, 80 and over , Collagen/therapeutic use , Female , Humans , Injections , Middle Aged , Prospective Studies , Quality of Life , Reoperation , Reproducibility of Results , Surveys and Questionnaires , Time Factors , Treatment Outcome
18.
BMC Dermatol ; 19(1): 14, 2019 10 18.
Article in English | MEDLINE | ID: mdl-31647007

ABSTRACT

BACKGROUND: Increasing resistance of head lice against neurotoxic agents and safety concerns have led to the search for treatment alternatives. Dimeticones with a physical mode of action are safe, and bear a reduced risk for the development of resistance. METHODS: We performed in vitro bioassays to assess pediculicidal and ovicidal activities of a new dimeticone-based product, and a randomized controlled clinical trial to assess efficacy, following 10 min application. Of 153 individuals screened, 100 participants with active head louse infestations were randomly assigned to treatment with either a dimeticone-based test product, or a 0.5% permethrin-based reference product (50 participants per group). Participants received two topical applications of either the test (10 min) or reference products (45 min) at days 0 and 7 or 8. Outcome measures included the efficacies of treatment and their safety, as well as global and local tolerability at baseline, and days 1, 7, and 10. RESULTS: After 10 min exposure, all lice treated with the dimeticone test product were classified as non-viable in the in vitro assay. Ovicidal activity after treatment of eggs with the dimeticone test product was 96.8%. In the clinical trial, 96 patients completed all study visits. In the full analysis set (FAS) population, on day 1 after one application, 98% of patients were cured in the test group, as compared to 84% cured in the reference group. All participants in both groups were free of head lice on day 10, following two applications (100% cure rate). In total, 42 adverse events (AEs) in 23 patients of both treatment groups were recorded, with the majority of AEs classified as mild. CONCLUSIONS: We have shown a high level of pediculicidal and ovicidal activity, and clinical efficacy and safety, of a brief application of a new dimeticone-based product. The short application time and reduced risk for the development of resistance are key drivers for improved patients' compliance. TRIAL REGISTRATION: EU Clinical Trials Register EudraCT  2016-004635-20 . Registered 14 November 2016.


Subject(s)
Dimethylpolysiloxanes/therapeutic use , Insecticides/therapeutic use , Lice Infestations/drug therapy , Pediculus/drug effects , Permethrin/therapeutic use , Scalp Dermatoses/drug therapy , Administration, Topical , Adolescent , Adult , Animals , Child , Child, Preschool , Dimethylpolysiloxanes/adverse effects , Dimethylpolysiloxanes/pharmacology , Female , Humans , In Vitro Techniques , Insecticides/adverse effects , Insecticides/pharmacology , Male , Permethrin/pharmacology , Single-Blind Method
19.
J Appl Oral Sci ; 27: e20180556, 2019 Sep 09.
Article in English | MEDLINE | ID: mdl-31508791

ABSTRACT

OBJECTIVE: To evaluate the effect of ultrasonic and sonic activation on physicochemical properties of AH Plus, MTA Fillapex, ADSeal, GuttaFlow Bioseal, and GuttaFlow 2 sealers. METHODOLOGY: Three experimental groups were formed: no activation (NA), ultrasonic activation (UA), and sonic activation (SA). The sealers were manipulated according to the manufacturers' instructions. A 3-mL syringe was adapted to receive 1 mL of sealer. Activation was performed with a 20/.01 ultrasonic insert (20 s/1W) in the UA group. A size 35.04 sonic tip was used (20 s/10,000 cycles/min-1) in the SA group. The molds for physicochemical analysis were filled and evaluated according to ANSI/ADA specification no. 57: setting time (ST), flow (FL), dimensional change (DC), solubility (SB), and radiopacity (RD). Statistical analysis was performed by Kruskal-Wallis, one-way ANOVA, and Tukey's tests (P<0.05). RESULTS: Regarding ST, only AH Plus and GuttaFlow 2 in the NA group met the ANSI/ADA standards. All FL values were greater than 20 mm in diameter, as determined by ANSI/ADA. The tested sealers and protocols did not comply with the ANSI/ADA standards for DC. As for SB, only MTA Fillapex, regardless of the activation protocol, did not follow the ANSI/ADA standards. All of the investigated sealers, regardless of the activation protocol, presented radiographic density higher than 3 mm Al, as proposed by ANSI/ADA. CONCLUSIONS: UA and SA promoted changes in the physicochemical properties of the evaluated root canal sealers, mainly in ST and F. Thus, it is important to evaluate the physicochemical properties of endodontic sealers associated with activation techniques prior to clinical application in order to determine whether the properties follow the parameters set by ANSI/ADA, ensuring safety and quality of root canal filling.


Subject(s)
Aluminum Compounds/chemistry , Calcium Compounds/chemistry , Dimethylpolysiloxanes/chemistry , Epoxy Resins/chemistry , Gutta-Percha/chemistry , Oxides/chemistry , Root Canal Filling Materials/chemistry , Silicates/chemistry , Ultrasonic Waves , Analysis of Variance , Drug Combinations , Materials Testing , Reference Values , Reproducibility of Results , Solubility , Statistics, Nonparametric , Surface Properties , Time Factors
20.
Int. braz. j. urol ; 45(5): 989-998, Sept.-Dec. 2019. tab, graf
Article in English | LILACS | ID: biblio-1040081

ABSTRACT

ABSTRACT Objective To evaluate the subjective and objective outcomes of Macroplastique® (MPQ) in women with stress urinary incontinence (SUI) secondary to intrinsic sphincter deficiency (ISD). Materials and Methods Following Institutional Review Board (IRB) approval, charts of non-neurogenic women with SUI secondary to ISD who underwent MPQ injection and had 6 months minimum follow-up were reviewed from a prospectively maintained database. Patients were divided into 3 groups: Naïve (Group I), Prior Anti-Incontinence Surgery (Group II), and combined Prior Bulking Agent and Anti-Incontinence Surgery (Group III). Data collected included SUI self-report, Urogenital Distress Inventory (UDI-6) Question 3, and VAS Quality of Life (QoL) Questionnaire scores at baseline and in follow-up. Three-dimensional ultrasound (3DUS) evaluated volume/configuration of MPQ. Success was defined after the last MPQ injection as a UDI-6 Question 3 score of 0 (dry) or 1, and no reoperation for SUI. Results From 2011-2017, 106 of 142 women met study criteria. At a median follow-up of 20 months (mean=26 months; range: 6-71), success rate was 41% for Group I, 40% for Group II, and 65% for Group III (p = 0.22). QoL scores were significantly improved over baseline in all groups. There was no significant difference in clinical outcome between the asymmetrical and symmetrical group on 3DUS. The completely dry rate was highest in Group III at 29%, compared to 4% for Group I and 15% for Group II (p = 0.05). Conclusion Macroplastique® improved subjective and objective outcome measures for SUI secondary to ISD as both a primary and secondary treatment option in women.


Subject(s)
Humans , Female , Adult , Aged , Aged, 80 and over , Urethral Diseases/complications , Urinary Incontinence, Stress/surgery , Urinary Incontinence, Stress/etiology , Dimethylpolysiloxanes/therapeutic use , Quality of Life , Reoperation , Time Factors , Prospective Studies , Surveys and Questionnaires , Reproducibility of Results , Collagen/therapeutic use , Treatment Outcome , Injections , Middle Aged
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