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Effects of Thermal Cycling on Surface Hardness, Diametral Tensile Strength and Porosity of an Organically Modified Ceramic (ORMOCER)-Based Visible Light Cure Dental Restorative Resin
Published in P. Mereena Luke, K. R. Dhanya, Didier Rouxel, Nandakumar Kalarikkal, Sabu Thomas, Advanced Studies in Experimental and Clinical Medicine, 2021
ORMOCERS are very promising materials. Although ORMOCERS are very promising, few investigations [6] have confirmed the potential of ORMOCERS as biomaterials or low-contraction materials applied to teeth restoration. The two composites (Definite® (Degussa AG, Hanau, Germany) or Admira® (Voco GmbH, Cuxhaven, Germany) available in the market based on ORMOCER technology. Admira composite contained 78% inorganic particles (barium and aluminum silicate) with an average size of 0.7 μ and the organic fraction composed of 65.5%, conventional organic dimethacrylates such as BisGMA, and UDMA along with 34.5% of triethylene glycol dimethacrylate (TEGDMA). The concept of ORMOCER [7] is to combine properties of organic polymers with glass-like materials to generate new/synergistic properties. The processing steps are based on sol-gel type reaction. Our previous studies reported [8–12] the development of a noncytotoxic and biocompatible organically modified ceramic composite with lower polymerization shrinkage compared to a composite containing BisGMA.
Application of Bioresponsive Polymers in Drug Delivery
Published in Deepa H. Patel, Bioresponsive Polymers, 2020
Manisha Lalan, Deepti Jani, Pratiksha Trivedi, Deepa H. Patel
Ding et al. designed injectable hydrogels based on glycol CS and benz-aldehyde-capped poly(ethylene glycol)-block-poly(propylene glycol)-block-poly(ethylene glycol) (PEO-PPO-PEO). In vivo tests using a rat model demonstrated that the hydrogel underwent a sol-gel transition at physiological conditions. These hydrogels have the ability to encapsulate both hydrophilic and hydrophobic drugs and can control the release profile by varying temperature or pH [145].
Scintillating quantum dots
Published in Sam Beddar, Luc Beaulieu, Scintillation Dosimetry, 2018
Claudine Nì. Allen, Marie-Ève Lecavalier, Sébastien Lamarre, Dominic Larivière
In recent years, the sol–gel process has been recognized as an extremely useful strategy to encapsulate scintillant in a glassy matrix, providing an alternative to the porous glass diffusion method used by Létant and Wang (2006). The term sol–gel refers to a process in which solid nanoparticles dispersed in a liquid (a sol) agglomerate together to form a continuous 3D network extending throughout the liquid (a gel). The method used to prepare the sol-gel uses a scintillant that cannot typically be introduced into a high-temperature glass melt.
Current advances in cell therapeutics: a biomacromolecules application perspective
Published in Expert Opinion on Drug Delivery, 2022
Samson A. Adeyemi, Yahya E. Choonara
Gellan gum forms stable hydrogels when cations are present in solution to prevent anionic carboxyl side groups from repelling and aggregating the helices. Monovalent cations provide an electric shield for the carboxyl group for more compact aggregation while divalent cations enable the binding of two carboxyl groups to yield stronger hydrogels [59]. These features enhance the sol-gel transition and are adaptable to facilitate stable therapeutic cell encapsulation. In addition, the in vivo mechanical properties of gellan gum can be enhanced through chemical modification of the carboxyl groups. For instance, a photo-crosslinked hydrogel was produced when the carboxyl group was crosslinked with methacrylates and revealed superior stability due to covalent bonding between the polymeric chains [60]. Studies have shown that increasing the elasticity of gellan gum by crosslinking reduced its cell adherence property [61,62]. As such, optimizing the elastic modulus of gellan gum hydrogels at lower concentrations (polymer and crosslinkers) enhances its cell adhesion potential on L-929 mouse fibroblasts cells. Similarly, improved biodegradation of gellan gum hydrogels can be achieved by increasing the number of acyl groups and to improve its cell adhesion efficiency for cell therapeutics [63,64].
Biofilm inhibition and antifouling evaluation of sol-gel coated silicone implants with prolonged release of eugenol against Pseudomonas aeruginosa
Published in Biofouling, 2021
Prasanth Rathinam, Bhasker Mohan Murari, Pragasam Viswanathan
Room temperature-processed acid-base catalyzed sol–gels have been used for various biomedical applications due to their widely accepted bioresorbable and biocompatible properties, tailorable composition and microstructure, excellent prolonged release properties, the ease of introducing multiple functional groups or elements, and the possibility of depositing them on any substrata by using inexpensive and straightforward techniques (Brinker and Scherer 2013). The sol–gel process involves the transition of a solution system from a liquid ‘sol’ (mostly colloidal) into a solid ‘gel’ phase through gelation, condensation and drying processes (Dehghanghadikolaei et al. 2018). Large quantities of biological molecules can be added into the porous solution system and uniformly distributed in the concrete matrix. Thus, sol–gels are prepared as thin films, coatings and hydrogels for fire-retardant, anti-static, water/oil repellent, insect-repellent, antimicrobial and catalytic applications, as well as for the encapsulation of enzymes, proteins, growth factors and antimicrobial agents (Brinker and Scherer 2013).
Magnetic carbon nanotubes: preparation, physical properties, and applications in biomedicine
Published in Artificial Cells, Nanomedicine, and Biotechnology, 2018
Mehrdad Samadishadlou, Masoud Farshbaf, Nasim Annabi, Taras Kavetskyy, Rovshan Khalilov, Siamak Saghfi, Abolfazl Akbarzadeh, Sepideh Mousavi
In addition to synthesis of high-grade metal or metal oxides/silica nanocomposites, sol–gel process can be employed for synthesis of metal nanocrystals and oxides/carbon hybrid composites. Hydrolysis and condensation of precursor in solution are fundamentals of this process. The quality, shape, structure, size, and properties of the product could be fully governed regulating the parameters including solvent, temperature, concentration of the precursors, the pH, agitation, and so on [61]. MCNTs also can be prepared by the sol–gel process. In a research by Modugno et al. [62], Fe2O3-MWCNTs nanocomposites were synthesized using a modified sol–gel process. As the first step in this method, the MWCNTs surface was activated with carboxylic acid groups and subsequently, using sol–gel process in which the g-Fe2O3 NPs was attached to the MWCNTs surface, at the same time with their synthesis. The main advantages of sol–gel process are low temperature operation which prevents oxidation of precursors and low cost. However, the nature of this process increases the possibility of product contamination which is the major drawback of sol–gel process.