Search results for "hydrogels"
showing 10 items of 299 documents
Tension Causes Unfolding of Intracellular Vimentin Intermediate Filaments
2020
Intermediate filament (IF) proteins are a class of proteins that constitute different filamentous structures in mammalian cells. As such, IF proteins are part of the load-bearing cytoskeleton and support the nuclear envelope. Molecular dynamics simulations show that IF proteins undergo secondary structural changes to compensate mechanical loads, which is confirmed by experimental in vitro studies on IF hydrogels. However, the structural response of intracellular IF to mechanical load is yet to be elucidated in cellulo. Here, in situ nonlinear Raman imaging combined with multivariate data analysis is used to quantify the intracellular secondary structure of the IF cytoskeletal protein viment…
Biocompatible Hydrogelators Based on Bile Acid Ethyl Amides
2016
Four novel bile acid ethyl amides were synthetized using a well-known method. All the four compounds were characterized by IR, SEM, and X-ray crystal analyses. In addition, the cytotoxicity of the compounds was tested. Two of the prepared compounds formed organogels. Lithocholic acid derivative 1 formed hydrogels as 1% and 2% (w/v) in four different aqueous solutions. This is very intriguing regarding possible uses in biomedicine. peerReviewed
Cationic Nanohydrogel Particles as Potential siRNA Carriers for Cellular Delivery
2012
Oligonucleotides such as short, double-stranded RNA (siRNA) or plasmid DNA (pDNA) promise high potential in gene therapy. For pharmaceutical application, however, adequate drug carriers are required. Among various concepts progressing in the market or final development, nanosized hydrogel particles may serve as novel transport media especially for siRNA. In this work, a new concept of synthesizing polymeric cationic nanohydrogels was developed, which offers a promising strategy to complex and transport siRNA into cells. For this purpose, amphiphilic reactive ester block copolymers were synthesized by RAFT polymerization of pentafluorophenyl methacrylate as reactive ester monomer together wi…
Tension causes structural unfolding of intracellular intermediate filaments
2020
AbstractIntermediate filament (IF) proteins are a class of proteins that constitute different filamentous structures in mammalian cells. As such, IF proteins are part of the load-bearing cytoskeleton and support the nuclear envelope. Molecular dynamics simulations have shown that IF proteins undergo secondary structural changes to compensate mechanical loads, which has been confirmed by experimental in vitro studies on IF hydrogels. However, the structural response of intracellular IF to mechanical load has yet to be elucidated in cellulo. Here, we use in situ nonlinear Raman imaging combined with multivariate data analysis to quantify the intracellular secondary structure of the IF cytoske…
Chemical modification of halloysite nanotubes for controlled loading and release.
2020
Clay minerals have been used for medical purposes from ancient times. Among them, the halloysite nanotube, an aluminosilicate of the kaolin group, is an emerging nanomaterial which possesses peculiar chemical characteristics. By means of suitable modifications, such as supramolecular functionalization or covalent modifications, it is possible to obtain novel nanomaterials with tunable properties for several applications. In this context the covalent grafting of suitable organic moieties on the external surface or in the halloysite lumen has been exploited to improve the loading and release of several biologically active molecules. The resulting hybrid nanomaterials have been applied as drug…
Printable Hydrogels Based on Alginate and Halloysite Nanotubes.
2022
The design of hydrogels for the controlled release of active species is an attractive challenge. In this work, we prepared hybrid hydrogels composed of halloysite nanotubes as the inorganic component, and alginate as the organic counterpart. The reported procedure allowed us to provide the resulting materials with a peculiar wire-like shape. Both optical and scanning electron microscopy were used to characterize the morphological properties of the hydrogel wires, whose diameters were ca. 0.19 and 0.47 mm, respectively. The possibility to be exploited as drug delivery systems was carried out by loading the nanoclay with salicylic acid and by studying the release profiles. Thermogravimetric e…
Keratin/alginate hybrid hydrogels filled with halloysite clay nanotubes for protective treatment of human hair
2022
Keratin/alginate hydrogels filled with halloysite nanotubes (HNTs) have been tested for the protective coating of human hair. Preliminary studies have been conducted on the aqueous colloidal systems and the corresponding hydrogels obtained by using Ca2+ ions as crosslinkers. Firstly, we have investigated the colloidal properties of keratin/alginate/HNTs dispersions to explore the specific interactions occurring between the biomacromolecules and the nanotubes. Then, the rheological properties of the hydrogels have been studied highlighting that the keratin/alginate interactions and the subsequent addition of HNTs facilitate the biopolymer crosslinking. Finally, human hair samples have been t…
Gellan gum-based delivery systems of therapeutic agents and cells.
2020
The purpose of this review is to make a summary of high quality research trends using gellan gum (GG) as a polymeric constituent for the design of innovative drug delivery systems and devices for biomedical applications, such as cell therapy and regenerative medicine. The use of gellan gum is described both in its native form and as chemically functionalized derivatives or physically mixed with natural or synthetic materials. Starting from a systematic study of recent research works, the main properties of the native polysaccharide have been highlighted and therefore some improvements have been focused thanks to the design of chemically functionalized derivatives and the use of composite ma…
Optical sensors for ethanol vapor based on polystyrene opals infiltrated with hydrogel
2013
This paper deals with a novel class of optical sensors for ethanol vapor, based on polystyrene opals infiltrated with a hydrogel sensitive to ethanol. Optical characterization of such opals has been performed, proving their effectiveness as sensors
Oxygen permeability of hydrogel contact lenses with organosilicon moieties
2002
Oxygen transport through two extended wear (day and night) hydrogel contact lenses that contain organosilicon moieties (balafilcon A and lotrafilcon A) was studied in the hydrate (hydrogel) and dry (xerogel) states. The water uptake increased the oxygen permeability [(Dk)app] and transmissibility [Dk/L(av)] coefficients of the dry materials by about 70%. The (Dk)app for the hydrated lenses was determined following the so-called stack procedure. The values obtained were 107 +/- 4 barrer for balafilcon A and 141 +/- 5 barrer for lotrafilcon A, about 5-10 times larger than those previously reported for conventional (without organosilicon moieties) extended wear hydrogels contact lenses. The Dk…