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Prague Medical Report 2023During the fabrication of a complete denture, functional impression is taken. Literature studies show that polydimethylsiloxane (condensation silicone) has not been... (Review)
Review
During the fabrication of a complete denture, functional impression is taken. Literature studies show that polydimethylsiloxane (condensation silicone) has not been reported by United States dental schools to perform border molding. Thus, the purpose of this article is to review the functional impression technique when border molding is performed with a laboratory condensation silicone putty.
Topics: Humans; Silicones; Denture, Complete
PubMed: 38069643
DOI: 10.14712/23362936.2023.28 -
Cancer Immunology Research Mar 2020Near-infrared photoimmunotherapy (NIR-PIT) is a newly developed and selective cancer treatment that induces necrotic and immunogenic cell death and utilizes a mAb...
Near-infrared photoimmunotherapy (NIR-PIT) is a newly developed and selective cancer treatment that induces necrotic and immunogenic cell death and utilizes a mAb conjugated to a photo-absorber dye, IR700DX, activated by NIR light. Although CD44 is a surface cancer marker associated with drug resistance, anti-CD44-IR700 NIR-PIT results in inhibited cell growth and prolonged survival in multiple tumor types. Meanwhile, CD25-targeted NIR-PIT has been reported to achieve selective and local depletion of FOXP3CD25CD4 regulatory T cells (Treg), which are primary immunosuppressive cells in the tumor microenvironment (TME), resulting in activation of local antitumor immunity. Combined NIR-PIT with CD44- and CD25-targeted agents has the potential to directly eliminate tumor cells and also amplify the immune response by removing FOXP3CD25CD4 Tregs from the TME. We investigated the difference in therapeutic effects of CD44-targeted NIR-PIT alone, CD25-targeted NIR-PIT alone, and the combination of CD44- and CD25-targeted NIR-PIT in several syngeneic tumor models, including MC38-luc, LL/2, and MOC1. The combined NIR-PIT showed significant tumor growth inhibition and prolonged survival compared with CD44-targeted NIR-PIT alone in all tumor models and showed prolonged survival compared with CD25-targeted NIR-PIT alone in MC38-luc and LL/2 tumors. Combined CD44- and CD25-targeted NIR-PIT also resulted in some complete remissions. Therefore, combined NIR-PIT simultaneously targeting cancer antigens and immunosuppressive cells in the TME may be more effective than either type of NIR-PIT alone and may have potential to induce prolonged immune responses in treated tumors.
Topics: Animals; Antineoplastic Agents, Immunological; Carcinoma, Lewis Lung; Cell Line, Tumor; Colonic Neoplasms; Disease Models, Animal; Female; Hyaluronan Receptors; Immunotherapy; Indoles; Infrared Rays; Interleukin-2 Receptor alpha Subunit; Isoindoles; Mice; Mice, Inbred C57BL; Molecular Targeted Therapy; Organosilicon Compounds; Phototherapy; T-Lymphocytes, Regulatory
PubMed: 31953245
DOI: 10.1158/2326-6066.CIR-19-0517 -
Nature Communications Apr 2020Carbon-11 (C) is one of the most ideal positron emitters for labeling bioactive molecules for molecular imaging studies. The lack of convenient and fast incorporation...
Carbon-11 (C) is one of the most ideal positron emitters for labeling bioactive molecules for molecular imaging studies. The lack of convenient and fast incorporation methods to introduce C into organic molecules often hampers the use of this radioisotope. Here, a fluoride-mediated desilylation (FMDS) C-labeling approach is reported. This method relies on thermodynamically favored Si-F bond formation to generate a carbanion, therefore enabling the highly efficient and speedy incorporation of [C]CO and [C]CHI into molecules with diversified structures. It provides facile and rapid access to C-labeled compounds with carbon-11 attached at various hybridized carbons as well as oxygen, sulfur and nitrogen atoms with broad functional group tolerance. The exemplified syntheses of several biologically and clinically important radiotracers illustrates the potentials of this methodology.
Topics: Acetoacetates; Carbon Radioisotopes; Fluorides; Methylation; Organosilicon Compounds; Raclopride; Radiopharmaceuticals
PubMed: 32269227
DOI: 10.1038/s41467-020-15556-7 -
Journal of Hazardous Materials Mar 2024Quaternary ammonium compounds (QACs) are commonly used as disinfectants for industrial, medical, and residential applications. However, adverse health outcomes have been...
Alcohol-free synthesis, biological assessment, in vivo toxicological evaluation, and in silico analysis of novel silane quaternary ammonium compounds differing in structure and chain length as promising disinfectants.
Quaternary ammonium compounds (QACs) are commonly used as disinfectants for industrial, medical, and residential applications. However, adverse health outcomes have been reported. Therefore, biocompatible disinfectants must be developed to reduce these adverse effects. In this context, QACs with various alkyl chain lengths (C12-C18) were synthesized by reacting QACs with the counterion silane. The antimicrobial activities of the novel compounds against four strains of microorganisms were assessed. Several in vivo assays were conducted on Drosophila melanogaster to determine the toxicological outcomes of Si-QACs, followed by computational analyses (molecular docking, simulation, and prediction of skin sensitization). The in vivo results were combined using a cheminformatics approach to understand the descriptors responsible for the safety of Si-QAC. Si-QAC-2 was active against all tested bacteria, with minimal inhibitory concentrations ranging from 13.65 to 436.74 ppm. Drosophila exposed to Si-QAC-2 have moderate-to-low toxicological outcomes. The molecular weight, hydrophobicity/lipophilicity, and electron diffraction properties were identified as crucial descriptors for ensuring the safety of the Si-QACs. Furthermore, Si-QAC-2 exhibited good stability and notable antiviral potential with no signs of skin sensitization. Overall, Si-QAC-2 (C14) has the potential to be a novel disinfectant.
Topics: Animals; Quaternary Ammonium Compounds; Silanes; Disinfectants; Drosophila melanogaster; Molecular Docking Simulation; Organosilicon Compounds
PubMed: 38246053
DOI: 10.1016/j.jhazmat.2024.133470 -
Cell Reports Jul 2021The immunological synapse is a complex structure that decodes stimulatory signals into adapted lymphocyte responses. It is a unique window to monitor lymphocyte activity...
The immunological synapse is a complex structure that decodes stimulatory signals into adapted lymphocyte responses. It is a unique window to monitor lymphocyte activity because of development of systematic quantitative approaches. Here we demonstrate the applicability of high-content imaging to human T and natural killer (NK) cells and develop a pipeline for unbiased analysis of high-definition morphological profiles. Our approach reveals how distinct facets of actin cytoskeleton remodeling shape immunological synapse architecture and affect lytic granule positioning. Morphological profiling of CD8 T cells from immunodeficient individuals allows discrimination of the roles of the ARP2/3 subunit ARPC1B and the ARP2/3 activator Wiskott-Aldrich syndrome protein (WASP) in immunological synapse assembly. Single-cell analysis further identifies uncoupling of lytic granules and F-actin radial distribution in ARPC1B-deficient lymphocytes. Our study provides a foundation for development of morphological profiling as a scalable approach to monitor primary lymphocyte responsiveness and to identify complex aspects of lymphocyte micro-architecture.
Topics: Actin-Related Protein 2-3 Complex; Adolescent; CD8-Positive T-Lymphocytes; Cell Line; Cell Shape; Cytoskeleton; Exocytosis; Humans; Imaging, Three-Dimensional; Immunological Synapses; Killer Cells, Natural; Male; Organoselenium Compounds; Organosilicon Compounds; Single-Cell Analysis; T-Lymphocytes; Thiones; Uracil; Wiskott-Aldrich Syndrome Protein
PubMed: 34233185
DOI: 10.1016/j.celrep.2021.109318 -
BMC Ophthalmology Jul 2023To report a case in which silicone oil accidentally entered Berger's space (BS) after vitrectomy and to explore the effective treatments and possible etiological...
BACKGROUND
To report a case in which silicone oil accidentally entered Berger's space (BS) after vitrectomy and to explore the effective treatments and possible etiological mechanisms.
CASE PRESENTATION
A 68-year-old male underwent vitrectomy and silicone oil injection for the treatment of retinal detachment (RD) in the right eye. Six months later, we noticed an unexpected lens-like round translucent substance located behind the posterior lens capsule and diagnosed it as BS filled by silicone oil. Subsequently, we conducted vitrectomy and the drainage of the silicone oil in BS in the second surgery. A 3-month follow-up showed significant anatomic recovery and visual recovery.
CONCLUSIONS
Our case report presents a patient with silicone oil entering BS after vitrectomy and provides photographs of BS from a relatively unique perspective. Furthermore, we illustrate the surgical treatment procedure and reveal the possible etiology and prevention method of silicon oil entering BS, which will provide good insights for clinical diagnosis and treatment.
Topics: Male; Humans; Aged; Silicone Oils; Silicones; Drainage; Eye; Lens, Crystalline
PubMed: 37430200
DOI: 10.1186/s12886-023-03035-8 -
BMC Oral Health Sep 2022This study aimed to compare the dimensional accuracy, hydrophilicity and detail reproduction of the hybrid vinylsiloxnether with polyether and polyvinylsiloxane parent...
BACKGROUND
This study aimed to compare the dimensional accuracy, hydrophilicity and detail reproduction of the hybrid vinylsiloxnether with polyether and polyvinylsiloxane parent elastomers using modified digital techniques and software. This was done in an attempt to aid in solving the conflict between the different studies published by competitive manufacturers using different common manual approaches.
METHODS
A polyether, polyvinylsiloxanes and vinyl polyether silicone hybrid elastomeric impression materials were used in the study. Dimensional accuracy was evaluated through taking impressions of a metallic mold with four posts representing a partially edentulous maxillary arch, that were then poured with stone. Accuracy was calculated from the mean of measurements taken between fixed points on the casts using digital single-lens reflex camera to produce high-resolution digital pictures for all the casts with magnification up to 35×. Hydrophilicity was assessed by contact angle measurements using AutoCAD software. The detail reproduction was measured under dry conditions according to ANSI/ADA Standard No. 19 and under wet conditions as per ISO 4823. A metallic mold was used with three V shaped grooves of 20, 50, and 75 µm width. Specimens were prepared and examination was made immediately after setting using digital images at a magnification of 16×.
RESULTS
The hybrid impression (0.035 mm) material showed significantly higher dimensional accuracy compared to the polyether (0.051 mm) but was not as accurate as the polyvinyl siloxane impression material (0.024 mm). The contact angles of the hybrid material before and after setting was significantly lower than the parent materials. With regard to the detail reproduction, the three tested materials were able precisely to reproduce the three grooves of the mold under dry conditions. Whereas, under wet conditions, the hybrid material showed higher prevalence of well-defined reproduction of details same as polyether but higher than polyvinylsiloxane that showed prevalence of details with loss of sharpness and continuity.
CONCLUSIONS
The digital technique used could be a more reliable and an easier method for assessment of impression materials properties. The hybridization of polyvinyl siloxane and polyether yielded a promising material that combines the good merits of both materials and overcomes some of their drawbacks.
Topics: Dental Impression Materials; Dental Impression Technique; Elastomers; Humans; Materials Testing; Polyvinyls; Silicones; Siloxanes; Surface Properties
PubMed: 36064393
DOI: 10.1186/s12903-022-02419-4 -
Molecules (Basel, Switzerland) Oct 2022Barium titanate (BT) recently gained new interest in the preparation of dielectric and piezoelectric lead-free materials for applications in sensors, electronics, energy...
Barium titanate (BT) recently gained new interest in the preparation of dielectric and piezoelectric lead-free materials for applications in sensors, electronics, energy harvesting and storage fields. Barium titanate nanocomposites can achieve attractive performance, provided that the compatibility between ceramic particles and polymeric matrices is enhanced to the benefit of the physical properties of the final composite. Tuning the particle-matrix interface through particle functionalization represents a viable solution. In this work, surface functionalization of BT nanoparticles (NPs), obtained by hydrothermal synthesis, with 3-glycidyloxypropyltrimethoxysilane, 2-[(acetoxy(polyethyleneoxy)propyl]triethoxysilane and triethoxysilylpropoxy(polyethyleneoxy)dodecanoate, was performed after optimizing the hydroxylation process of the NPs to improve their surface reactivity and increase the yield of grafting. Solid-state nuclear magnetic resonance and thermogravimetric analysis were used to quantify the molecules grafted onto the ceramic nanoparticles. Both bare and functionalized particles were employed in the realization of epoxy- and polydimethylsiloxane (PDMS)-based nanocomposites. Functionalization was proven to be beneficial for particle dispersibility and effective for particle alignment in the PDMS matrix. Moreover, the dielectric constant measurements revealed the potential of PDMS-based nanocomposites for applications in the field of dielectric elastomers.
Topics: Barium; Dimethylpolysiloxanes; Elastomers; Laurates; Nanocomposites; Organosilicon Compounds; Titanium
PubMed: 36235034
DOI: 10.3390/molecules27196499 -
Materials Science & Engineering. C,... Nov 2018Cancer, disease and trauma to the larynx and their treatment can lead to permanent loss of structures critical to voice, breathing and swallowing. Engineered partial or...
Cancer, disease and trauma to the larynx and their treatment can lead to permanent loss of structures critical to voice, breathing and swallowing. Engineered partial or total laryngeal replacements would need to match the ambitious specifications of replicating functionality, outer biocompatibility, and permissiveness for an inner mucosal lining. Here we present porous polyhedral oligomeric silsesquioxane-poly(carbonate urea) urethane (POSS-PCUU) as a potential scaffold for engineering laryngeal tissue. Specifically, we employ a precipitation and porogen leaching technique for manufacturing the polymer. The polymer is chemically consistent across all sample types and produces a foam-like scaffold with two distinct topographies and an internal structure composed of nano- and micro-pores. While the highly porous internal structure of the scaffold contributes to the complex tensile behaviour of the polymer, the surface of the scaffold remains largely non-porous. The low number of pores minimise access for cells, although primary fibroblasts and epithelial cells do attach and proliferate on the polymer surface. Our data show that with a change in manufacturing protocol to produce porous polymer surfaces, POSS-PCUU may be a potential candidate for overcoming some of the limitations associated with laryngeal reconstruction and regeneration.
Topics: Animals; Cells, Cultured; Epithelial Cells; Fibroblasts; Larynx; Organosilicon Compounds; Polyurethanes; Swine; Tissue Engineering; Tissue Scaffolds
PubMed: 30184783
DOI: 10.1016/j.msec.2018.07.003 -
Journal of Pharmaceutical Sciences Nov 2021Protein aggregate formation in prefilled syringes (PFSs) can be influenced by protein adsorption and desorption at the solid-liquid interface. Although inhibition of...
Protein aggregate formation in prefilled syringes (PFSs) can be influenced by protein adsorption and desorption at the solid-liquid interface. Although inhibition of protein adsorption on the PFS surface can lead to a decrease in the amount of aggregation, the mechanism underlying protein adsorption-mediated aggregation in PFSs is unclear. This study investigated protein aggregation caused by protein adsorption on silicone oil-free PFS surfaces [borosilicate glass (GLS) and cycloolefin polymer (COP)] and the factors affecting the protein adsorption on the PFS surfaces. The adsorbed proteins formed multilayered structures that consisted of two distinct types of layers: proteins adsorbed on the surface of the material and proteins adsorbed on top of the proteins on the surface. A pH-dependent electrostatic interaction was the dominant force for protein adsorption on the GLS surface, while hydrophobic effects were dominant for protein adsorption on the COP surface. When the repulsion force between proteins was weak, protein adsorption on the adsorbed protein layer was increased for both materials and as a result, protein aggregation increased. Therefore, a formulation with high colloidal stability can minimize protein adsorption on the COP surface, leading to reduced protein aggregation.
Topics: Adsorption; Hydrophobic and Hydrophilic Interactions; Proteins; Silicone Oils; Surface Properties; Syringes
PubMed: 34310973
DOI: 10.1016/j.xphs.2021.07.007