Bioinspired Thermosensitive Hydrogel as a Vitreous Substitute: Synthesis, Properties, and Progress of Animal Studies

In many vitreal diseases, the surgeon removes the natural vitreous and replaces it with silicone oils, gases, or balanced salt solutions to fill the eyeball and hold the retina in position. However, these materials are often associated with complications and have properties that differ from natural vitreous. Herein, we report an extension of our previous work on the synthesis of a biomimetic hydrogel that is composed of thiolated gellan as an analogue of type II collagen and poly(methacrylamide-co-methacrylate-co-bis(methacryloyl)cystamine), a polyelectrolyte, as an analogue of hyaluronic acid. This thermosensitive hydrogel can be injected into the eye as a viscous solution at 45 °C. It then forms a physical gel in situ when it reaches body temperature, and later forms disulfide covalent crosslinks. In this article, we evaluated two different formulations of the biomimetic hydrogels for their physical, mechanical, and optical properties, and we determined their biocompatibility with several cell lines. Finally, we report on the progress of the four-month preclinical evaluation of our bio-inspired vitreous substitute in comparison to silicone oil or a balanced salt solution. We assessed the eyes with a slit-lamp examination, intraocular pressure measurements, electroretinography, and optical coherence tomography. Preliminary results are very encouraging for the continuing evaluation of our bio-inspired hydrogel in clinical trials.

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Thermo-Responsive Hydrogels Based on Methylcellulose/Persian Gum Loaded With Taxifolin Enhance Bone Regeneration: An in Vitro / in Vivo Study

10.21203/rs.3.rs-736612/v1 ◽

2021 ◽

Author(s):

Zahra Sadat Sajadi-Javan ◽

Jaleh Varshosaz ◽

Mina Mirian ◽

Maziar Manshaei ◽

Atousa Aminzadeh

Keyword(s):

Animal Studies ◽

Bone Defects ◽

Halloysite Nanotubes ◽

Thermosensitive Hydrogel ◽

Alizarin Red ◽

The Impact ◽

Responsive Hydrogels

Abstract In-situ forming hydrogels have gained noticeable attention to encapsulate osteogenic agents and regenerate irregular-shape bone defects. In this study, a novel thermosensitive hydrogel based on blended methylcellulose (MC) with Persian gum (PG) was fabricated and enriched with taxifolin (TAX) loaded halloysite nanotubes (HNTs) to enhance mechanical and biological characteristics of the hydrogel in bone tissue engineering. The injectability, mechanical and rheological tests were performed for different hydrogel formulations containing 0.25-1.5 w/v% PG and 1-7 w/v% HNTs. Also, to evaluate the impact of PG and HNTs on hydrogel behavior, the degradation rate and swelling degree of hydrogels were assessed. The optimized MC/PG/HNTs hydrogel containing 1% PG and 3% HNTs (MC/PG-1/HNTs 3%) was easily injectable and gelled rapidly at physiological temperature, while it had the highest mechanical strength due to the existence of PG and HNTs. In vitro release study of TAX from this system also revealed more sustained release compared to HNTs-TAX nanoparticles. Furthermore, the interaction of cells with hydrogel and osteo-conductivity was studied using osteoblast-like cells (MG-63). Results showed higher cell adhesion, proliferation, and gene expression for MC/PG-1/HNTs-TAX hydrogel compared to MC/PG-1 and MC/PG-1/HNTs 3% possibly due to the synergic effect of HNTs and TAX. In addition, Alizarin Red S staining and alkaline phosphatase measurements indicated that the existence of HNTs-TAX promoted osteogenic differentiation. Eventually, animal studies on the femoral defects indicated improved remedy when using the MC/PG-1/HNTs-TAX hydrogel carrying MG-63 cells.

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Drill fluid selection for the SUBGLACIOR probe: a review of silicone oil as a drill fluid

Annals of Glaciology ◽

10.3189/2014aog68a028 ◽

2014 ◽

Vol 55 (68) ◽

pp. 311-321 ◽

Cited By ~ 8

Author(s):

J. Triest ◽

O. Alemany

Keyword(s):

Silicone Oil ◽

Ice Core ◽

Environmental Evaluation ◽

Core Drilling ◽

Drill Fluid ◽

Silicone Oils ◽

Selection For ◽

Analytical System ◽

Selection Of

AbstractAs part of the ICE&LASER/SUBGLACIOR projects, an innovative probe called SUBGLACIOR is developed with the aim of perforating the ice sheet down to depths of 3500 m in a single season and continuously measuring in situ the isotopic composition of the meltwater and the methane concentration in trapped gases. Ice chips generated by the electromechanical drilling will be removed from the borehole by circulating a drill fluid. The selection of this drill fluid is important as it will have a major impact on the performance and the environmental evaluation. A literature review of drilling liquids is carried out to select potential fluids for further detailed testing. The selected fluids are varying grades of silicone oils, known as linear polydimethylsiloxanes, and ESTISOL™ 140, an aliphatic ester. The requirements for this project are similar to those for other deep ice-core drilling projects but, due to the embedded analytical system and the speed of drilling, there are some specific considerations. Following extensive testing, we conclude that a silicone fluid with a kinematic viscosity of 3 mm2 s−1 (3 cSt) is ideally suitable and affordable. This evaluation provides new insights into the use of silicone oils as a drill fluid that are of use to the wider ice-core drilling community.

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Acoustic and elastic properties of silicone oil under high pressure

RSC Advances ◽

10.1039/c5ra03817k ◽

2015 ◽

Vol 5 (48) ◽

pp. 38056-38060 ◽

Cited By ~ 4

Author(s):

Xiaoxia Wang ◽

Chen Chen ◽

Xiaoli Huang ◽

Jiayu Wang ◽

Mingguang Yao ◽

...

Keyword(s):

High Pressure ◽

Elastic Properties ◽

Silicone Oil ◽

Brillouin Scattering ◽

Silicone Oils ◽

Scattering Spectra

Brillouin scattering spectra of three silicone oils with different viscosity, including two polydimethylsiloxanes (PDMS) and one polyphenylmethylsiloxane (PPMS), have been studied under high pressure.

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Polymorphous Al-MOFs Based on V-Shaped Linker Molecules: Synthesis, Properties, and in Situ Investigation of Their Crystallization

Inorganic Chemistry ◽

10.1021/acs.inorgchem.7b00202 ◽

2017 ◽

Vol 56 (10) ◽

pp. 5851-5862 ◽

Cited By ~ 12

Author(s):

Martin Krüger ◽

A. Ken Inge ◽

Helge Reinsch ◽

Yuan-Han Li ◽

Mohammad Wahiduzzaman ◽

...

Keyword(s):

In Situ Investigation ◽

Synthesis Properties ◽

Linker Molecules

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In situ hybridization reveals differential spatial distribution of mRNAs for type I and type II collagen in the chick limb bud

Development ◽

10.1242/dev.103.1.111 ◽

1988 ◽

Vol 103 (1) ◽

pp. 111-118 ◽

Cited By ~ 1

Author(s):

C.J. Devlin ◽

P.M. Brickell ◽

E.R. Taylor ◽

A. Hornbruch ◽

R.K. Craig ◽

...

Keyword(s):

In Situ Hybridization ◽

Limb Development ◽

Type I Collagen ◽

Type Ii Collagen ◽

Limb Bud ◽

Type I ◽

Type Ii ◽

Mrna Accumulation ◽

Rna Probes

During limb development, type I collagen disappears from the region where cartilage develops and synthesis of type II collagen, which is characteristic of cartilage, begins. In situ hybridization using antisense RNA probes was used to investigate the spatial localization of type I and type II collagen mRNAs. The distribution of the mRNA for type II collagen corresponded well with the pattern of type II collagen synthesis, suggesting control at the level of transcription and mRNA accumulation. In contrast, the pattern of mRNA for type I collagen remained more or less uniform and did not correspond with the synthesis of the protein, suggesting control primarily at the level of translation or of RNA processing.

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Silicone Oils and their Properties used in Rhegmatogenous Retinal Detachment Surgery

Güncel Retina Dergisi (Current Retina Journal) ◽

10.37783/crj-0161 ◽

2019 ◽

pp. 176-180

Keyword(s):

Retinal Detachment ◽

Rhegmatogenous Retinal Detachment ◽

Silicone Oil ◽

Chemical Properties ◽

Retinal Tear ◽

Giant Retinal Tear ◽

Silicone Oils ◽

Medical Indications ◽

Physical And Chemical ◽

And Chemical Properties

Silicone oils are polymer structures including siloxane repeats in the center. Copolymers formed by combining these polymers at different ratios constitute different silicone structures with different physical and chemical properties. The presence of several factors such as trauma, giant retinal tear, proliferative vitreoretinopathy and retinal tear in posterior localization is the main medical indications for the use of silicone oils in the surgery of rhegmatogenous retinal detachment. Problems associated with the need for a second surgical intervention to remove silicone oil, the emulsification of silicone oil with the problem this emulsification, and the presence of foreign structure in eye globe are the most important conditions limiting the use of silicone oil.

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Natural-Convection Heat Transfer in Liquids Confined by Two Horizontal Plates and Heated From Below

Journal of Heat Transfer ◽

10.1115/1.4008124 ◽

1959 ◽

Vol 81 (1) ◽

pp. 24-28 ◽

Cited By ~ 192

Author(s):

Samuel Globe ◽

David Dropkin

Keyword(s):

Heat Transfer ◽

Silicone Oil ◽

Convection Heat Transfer ◽

Test Results ◽

Transfer Coefficients ◽

Heat Transfer Coefficients ◽

Silicone Oils ◽

Prandtl Numbers ◽

The Relationship ◽

Rayleigh Numbers

This paper presents results of an experimental investigation of convective heat transfer in liquids placed between two horizontal plates and heated from below. The liquids used were water, silicone oils of 1.5, 50, and 1000 centistoke kinematic viscosities, and mercury. The experiments covered a range of Rayleigh numbers between 1.51(10)5 and 6.76(10)8. and Prandtl numbers between 0.02 and 8750. Tests were made in cylindrical containers having copper tops and bottoms and insulating walls. For water and silicone oils the container was 5 in. in diam and 2 in. high. For mercury, two containers were used, both 5.28 in. in diameter, but one 1.39 in. high and another 2.62 in. high. In all cases the bottom plates were heated by electric heaters. The top plates were air-cooled for the water and silicone-oil experiments and water-cooled for the mercury tests. To prevent amalgamation, the copper plates of the mercury container were chromium plated. Surface temperatures were measured by thermocouples embedded in the plates. The test results indicate that the heat-transfer coefficients for all liquids investigated may be determined from the relationship Nu=0.069Ra13Pr0.074 In this equation the Nusselt and Rayleigh numbers are based on the distance between the copper plates. The results of this experiment are in reasonable agreement with the data reported by others who used larger containers and different fluids.

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Effect of H2O on the Pressure-Induced Amorphization of Hydrated AlPO4-17

Molecules ◽

10.3390/molecules24162864 ◽

2019 ◽

Vol 24 (16) ◽

pp. 2864 ◽

Cited By ~ 1

Author(s):

Frederico G. Alabarse ◽

Boby Joseph ◽

Andrea Lausi ◽

Julien Haines

Keyword(s):

Pressure Range ◽

Silicone Oil ◽

Structural Response ◽

Microporous Material ◽

X Ray ◽

Guest Species ◽

Order Of Magnitude ◽

Diamond Anvil ◽

The Stability

The incorporation of guest species in zeolites has been found to strongly modify their mechanical behavior and their stability with respect to amorphization at high pressure (HP). Here we report the strong effect of H2O on the pressure-induced amorphization (PIA) in hydrated AlPO4-17. The material was investigated in-situ at HP by synchrotron X-ray powder diffraction in diamond anvil cells by using non- and penetrating pressure transmitting media (PTM), respectively, silicone oil and H2O. Surprisingly, in non-penetrating PTM, its structural response to pressure was similar to its anhydrous phase at lower pressures up to ~1.4 GPa, when the amorphization was observed to start. Compression of the structure of AlPO4-17 is reduced by an order of magnitude when the material is compressed in H2O, in which amorphization begins in a similar pressure range as in non-penetrating PTM. The complete and irreversible amorphization was observed at ~9.0 and ~18.7 GPa, respectively, in non- and penetrating PTM. The present results show that the insertion of guest species can be used to strongly modify the stability of microporous material with respect to PIA, by up to an order of magnitude.

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An ROS-sensitive tegafur-PpIX-heterodimer-loaded in situ injectable thermosensitive hydrogel for photodynamic therapy combined with chemotherapy to enhance the tegafur-based treatment of breast cancer

Biomaterials Science ◽

10.1039/d0bm01519a ◽

2021 ◽

Vol 9 (1) ◽

pp. 221-237

Author(s):

Zhiqiang Zhang ◽

Anning Li ◽

Xingqi Min ◽

Qunqun Zhang ◽

Jun Yang ◽

...

Keyword(s):

Breast Cancer ◽

Photodynamic Therapy ◽

Protoporphyrin Ix ◽

Temperature Sensitive ◽

Thermosensitive Hydrogel ◽

Temperature Sensitive Hydrogel

A temperature-sensitive hydrogel encapsulating tegafur and protoporphyrin IX dimers could be delivered intratumorally for synergetic chemotherapy and photodynamic therapy.

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