Enhanced Release of Molecules upon Ultraviolet (UV) Light Irradiation from Photoresponsive Hydrogels Prepared from Bifunctional Azobenzene and Four-Arm Poly(ethylene glycol)

2017 ◽  
Vol 10 (36) ◽  
pp. 30071-30080 ◽  
Author(s):  
Shiva K. Rastogi ◽  
Hailee E. Anderson ◽  
Joseph Lamas ◽  
Scott Barret ◽  
Travis Cantu ◽  
...  
2013 ◽  
Vol 634-638 ◽  
pp. 2272-2275
Author(s):  
Chang Wang Shao ◽  
Guo Wei Zhou ◽  
De Lan Xu ◽  
Bin Sun

Rod-shaped TiO2 was synthesized via homogeneous precipitation by using PEG and urea as the structure directing agent and precipitation agent, respectively. The prepared samples were characterized by XRD, TEM, and FESEM. The XRD patterns of the samples indicated that the crystalline phase was anatase. TEM and FESEM images revealed the morphology of prepared TiO2 samples were rod-shaped, and densely packed with plenty of spherical-shaped units. RTS3 exhibited the highest photocatalytic activity for degradation of papermaking wastewater under UV light irradiation. CODCr percent degradation was about 75% under UV light irradiation in 12 h for RTS3.


2021 ◽  
Author(s):  
Tae Woong Kang ◽  
Atsushi Tamura ◽  
Yoshinori Arisaka ◽  
Nobuhiko Yui

Visible light-degradable supramolecular gels were designed using polyrotaxanes (PRXs) containing a bulky trithiocarbonate group as stopper molecules that are cleaved by visible light irradiation. The visible-light-degradable PRXs comprise poly(ethylene glycol)...


Micromachines ◽  
2021 ◽  
Vol 12 (9) ◽  
pp. 1111
Author(s):  
Min-Jae Lee ◽  
Seon-Young Park ◽  
A-Young Sung

The functional hydrogel lens containing 2-hydroxyethylmethacrylate (HEMA) was manufactured by thermal polymerization. The physical properties of the produced hydrogel lens were measured and analyzed. In this study, HEMA, ethylene glycol dimethacrylate (EGDMA), and azobisisobutyronitrile (AIBN) were used for thermal copolymerization. Additionally, poly (ethylene glycol) methyl ether methacrylate (PEGMEMA), 3-(Triethoxysilyl) propyl isocyanate (TEPI), and cerium(Ⅳ) oxide nanoparticles were used as additives to make a functional hydrogel lens. The mixture was heated at 100 °C for 90 min to produce the hydrogel ophthalmic lens by the cast mold method. The resulting physical properties showed that the water content and refractive index of the sample were in the ranges of 38.06~42.11% and 1.426~1.436, respectively. The addition of cerium oxide nanoparticles lowered the contact angle and allowed the hydrogel lens to block UV light. The tensile strength was also improved by 52.13% through cerium oxide nanoparticles, and up to 123.4% by using TEPI. Based on the results of this study, the produced ophthalmic lens is suitable for durable, UV-blocking high-performance lenses.


MRS Advances ◽  
2018 ◽  
Vol 3 (30) ◽  
pp. 1697-1702 ◽  
Author(s):  
Kerolos Hanna ◽  
Ozgul Yasar-Inceoglu ◽  
Ozlem Yasar

AbstractTissue Engineering has been studied to develop tissues as an alternative approach to the organ regeneration. Successful artificial tissue growth in regenerative medicine depends on the precise scaffold fabrication as well as the cell-cell and cell-scaffold interaction. Scaffolds are extracellular matrices that guide cells to grow in 3D to regenerate the tissues. Cell-seeded scaffolds must be implanted to the damaged tissues to do the tissue regeneration. Scaffolds’ mechanical properties and porosities are the two main scaffold fabrication parameters as the scaffolds must be able to hold the pressure due to the surrounding tissues after the implantation process. In this research, scaffolds were fabricated by photolithography and Poly(ethylene glycol) Diacrylate (PEGDA) which is a biocompatible and biodegradable material was used as a fabrication material. In order to compare the compressive properties of PEGDA only with the compressive properties of drug delivered PEGDA, firstly, PEGDA only solutions were prepared. Then, PEGDA was mixed with Meloxicam 15 mg, Hydrochlorothiazide 12.5 mg, Cyclobenzaprine 10 mg and Spironolactone-hctz 25-25 mg respectively and they were placed under the UV light for about 15 minutes to solidify the cylindrical shaped hydrogels. 5 samples from each group were fabricated under the same conditions. Laboratory temperature, photoinitiator concentration and UV light intensity was kept constant during the fabrication process. After the fabrication was completed, Instron 3369 universal mechanical testing machine with the 5 mm/min compression rate was used to do the compression tests to compare the drug effects on PEGDA hydrogels. Our results indicate that average ultimate strength of PEGDA only samples was 3.820 MPa. Also, due to the fact that Meloxicam 15 mg and PEGDA mixture did not solidify under the UV light at all, compression test could not be performed for PEGDA- Meloxicam 15 mg mixture. However, Hydrochlorothiazide 12.5 mg, Cyclobenzaprine 10 mg and Spironolactone-hctz 25-25 mg dissolved within the PEGDA completely and our compression results show that average ultimate strengths were 3.372 MPa, 1.602 MPa, 1.999 MPa respectively. This preliminary research showcases that compressive properties of the PEGDA-based photopolymerized scaffolds can be altered with the control of the drug type and drug concentration.


2020 ◽  
Vol 6 (3) ◽  
pp. 189-192
Author(s):  
Jennifer Huling ◽  
Beate Lyko ◽  
Sabine Illner ◽  
Nicklas Fiedler ◽  
Niels Grabow ◽  
...  

AbstractElectrospinning is a popular method for creating nonwoven fiber materials for a wide variety of applications. In the field of biomaterials, electrospun materials are favoured because of a high surface-to-volume ratio which can be useful for drug loading and release, and because nanoscale fibers mimic native tissue structures, improving cell interactions. However limitations exist with regards to traditional solvent evaporation-based electrospinning techniques. A new area of research into reactive electrospinning is investigating methods of electrospinning that rely on in situ crosslinking rather than solvent evaporation to stabilize fibers. These techniques can potentially reduce the waste of excess solvents and make it easier to electrospin water soluble polymers. In this work, UV photocrosslinked PEGDA is evaluated as a material for reactive electrospinning. To facilitate the electrospinning process poly(ethylene glycol) diacrylate (PEGDA) is combined with polyvinyl alcohol (PVA). PEGDA/PVA solutions can be successfully electrospun under constant UV light exposure to initiate the crosslinking of the PEGDA. Reactive electrospun fibers appear more stable immediately after spinning and after washing with water, indicating successful photo crosslinking.


2019 ◽  
Vol 890 ◽  
pp. 290-300 ◽  
Author(s):  
João Lopes ◽  
Rita Fonseca ◽  
Tânia Viana ◽  
Cristiana Fernandes ◽  
Pedro Morouço ◽  
...  

Tissue Engineering depends on broadly techniques to regenerate tissues and/or organ functions. To do so, tailored polymeric and/or hydrogel scaffolds may be used to ensure the appropriate regeneration. Hydrogels are suitable materials for constructing cell-laden matrices as they can be produced with incorporation of cells and rapidly cross-linkedin situthrough photopolymerisation reactions. Measurement of the polymerization degree, as well as resistance to compression and water retention are fundamental tests to evaluate the characteristics of hydrogels. In this work, free-radical polymerisation of poly (ethylene glycol)-dimethacrylate (PEGDMA) in UV light was assessed. Several hydrogels with different photoinitiator and water contents were produced to evaluate their influence on hydrogels behaviour. Experiments showed that variations on water and photoinitiator content induce changes in the physical and chemical behaviour of hydrogels. As it was found, water content prevents polymerisation to occur and reduces the mechanical properties of hydrogels weakening them. Furthermore, differences were found in varying water content from 15 to 30%, since this increase turned hydrogels more fragile and increase their stabilization time for water retention.


2012 ◽  
Vol 531 ◽  
pp. 580-583
Author(s):  
Lin Juan Yu ◽  
Ren Gui Peng ◽  
Yuan Zhen Wang ◽  
Yue E Liu ◽  
Ying Kui Yang

A liquid crystalline polyurethane elastomer (LCPUE) film has been successfully fabricated by thermal polycondensation of azobenzene mesogenic monomer containing bishydroxyl groups with tolylene 2,4-diisocyanate, linear poly(ethylene glycol) and star pentaerythritol ethoxylate as a cross-linker. The thermotropic film of LCPUE was found to show reversible photoisomerism behavior and could be bent towards the direction of UV-light irradiation. The mechanical force generated in the LCPUE film upon photoirradiation was calculated to be 260–285 kPa according to the dynamic mechanical analysis. Thus this material may promise potential applications in remote light-controlled actuators.


2019 ◽  
Vol 10 (10) ◽  
Author(s):  
Anton Bonartsev ◽  
Vera Voinova ◽  
Elizaveta Akoulina ◽  
Andrey Dudun ◽  
Irina Zharkova ◽  
...  

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