Microstructure plays an essential role in the control of hydrogel properties. It is also important factor when cells or drugs are encapsulated inside hydrogel. In this work, microstructures hydrazone crosslinked hyaluronan-, alginate- and gellan gum-based hydrogels were evaluated thoroughly for first time by using rheology- diffusion (fluorescence recovery after photobleaching, FRAP)-based methods. The effect gel parameters on viscoelastic properties hydrogels, further their structural (mesh...

A microparticulate protein delivery system was developed using collagen, from the medusa Catostylus tagi, as a polymeric matrix. Collagen microparticles (CMPs) were produced by an emulsification-gelation-solvent extraction method and high loading efficiency found for entrapment of lysozyme α-lactalbumin. CMPs cross-linked with 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC). The uncross-linked spherical, rough-surfaced, presenting estimated median size 28 µm laser diffraction. Upon...

Age-related macular degeneration (AMD) is a leading cause of blindness in developed countries, characterised by the retinal pigment epithelium (RPE), pigmented cell monolayer that closely interacts with photoreceptors. RPE transplantation thus considered very promising therapeutic option to treat this disease. In work, porous honeycomb-like films are for first time investigated as scaffold materials human embryonic stem cell-derived (hESC-RPE). By changing conditions during film preparation,...

A preliminary biochemical approach to the study of collagen isolated from medusa Catostylus tagi is reported and results are discussed in view its use as a natural matrix for biomedical applications. Collagen jellyfish umbrella was by pepsin digestion purified dialysis salt precipitation. As expected, glycine represented almost one-third total amino acids. Aromatic amino-acid content very low imino acids were fewer than collagens fish mammalian sources. Results SDS-PAGE, ion-exchange...

The jellyfish Catostylus tagi was studied as a food source. C. is an abundant and unexplored resource of the Southwest Portuguese coast. umbrella oral arms were separately assayed. Inorganics, nitrogen, lipid content estimated, being identified major mineral, amino acid fatty (FA) components. scavenging capacity aqueous extracts for hydroxyl (HO•), superoxide anion (O2 •-) 1,1-diphenyl-2-picrylhydrazyl (DPPH) radicals investigated, well their ferric ion reducing antioxidant power (FRAP)....

ABSTRACT Several different polysaccharides have been added to pluronic F127 (poloxamer 407) gels test their ability stabilize the against dissolution in aqueous media over time. The studied include κ‐carrageenan, chitosan, hyaluronic acid, pectin, alginate, hydroxyethylcellulose, and ethyl(hydroxyethyl)cellulose. Although all considered slowed down time of gels, unmodified only had a modest stabilization effect. However, hydrophobic modification with sufficiently long hydrocarbon chain (C 16...

Gene knockdown has emerged as an important tool for cancer gene therapy well viral infections and dominantly inherited genetic disorders. The generation of suitable siRNA delivery systems poses some challenges, namely, to avoid nuclease degradation, surpass the cytoplasmic membrane, release nucleic acids into cytosol. Aiming at evaluating ability thermoresponsive block copolymers formed by units N-isopropylacrylamide (3-acrylamidopropyl)trimethylammonium chloride efficiently deliver siRNAs,...

In vitro cell culture models representing the physiological and pathological features of outer retina are urgently needed. Artificial tissue replacements for patients suffering from degenerative retinal diseases similarly in great demand. Here, we developed a co-culture system based solely on use human induced pluripotent stem (hiPSC)-derived cells. For first time, hiPSC-derived pigment epithelium (RPE) endothelial cells (EC) were cultured opposite sides porous polylactide substrates...

This study reports on the processing of three-dimensional (3D) chitosan/bioactive glass composite scaffolds. On one hand, chitosan, as a natural polymer, has suitable properties for tissue engineering applications but lacks bioactivity. other bioactive glasses are known to be and promote higher level bone formation than any biomaterial type. However, hard, brittle, cannot shaped easily. Therefore, in past years, researchers have focused new composites. Difficulties reaching materials made...

The development of innovative materials for bone tissue engineering to promote regeneration while avoiding fibrous infiltration is paramount importance. Here, we combined the known osteopromotive properties bioactive glasses (BaGs) with biodegradability, biocompatibility, and ease shape/handle poly-l-

ABSTRACT In this work, a hydrophobically modified (HM) chitosan derivative was prepared by covalent linkage of C 12 groups to the backbone. HM‐chitosan microparticles were according an emulsification‐solvent evaporation method and naltrexone (NTX) used as model drug. For comparison, unmodified poly lactic‐ co ‐glycolic acid (PLGA) also tested carriers for NTX. formed viscous semi‐dilute solutions, suggesting high level chain entanglements hydrophobic associations. generally showed higher...

Hydrophobically modified hydroxyethylcellulose (HM-HEC) of different hydrophobicity has been used to stabilize pluronic gels against dissolution in an aqueous environment. While by itself dissolves within 1–2 days, the addition HM-HEC can part from dissolving for a period at least six months. A larger fraction gel remains undissolved when utilizing high concentrations and degree hydrophobic modification is increased. The stabilization fast makes these systems interesting drug delivery...

Degenerative retinal diseases are a leading cause of visual loss and irreversible blindness, particularly in the developed world. Retinal pigment cell (RPE) transplantation is nowadays considered most promising therapeutic approach for certain diseases, presence supportive scaffold has been essential to ensure success implant. In this work, collagen IV was covalently immobilized surface polyimide membranes, with purpose developing materials RPE culture. The covalent modification method...

Abstract In this study, we developed microfabricated porous membranes aimed at facilitating innervation in 3D cell culture models. The aim of the paper is to introduce a fabrication method for with adjustable size, shape and location pores without obstructing imaging or connectivity cells. based on making patterned SU-8 layer sacrificial aluminium by UV lithography releasing it etching. With proposed method, were able produce single-layer self-supporting that used as interfaces...

Introduction Thermoresponsive polymers have been widely investigated in modern drug delivery and gene systems, due to their potential load release the payload by simply modifying local temperature [1 Calejo MT, Sande SA, Nyström B. as vectors: architecture mechanism of action. Expert Opin. Drug Deliv. 2014;10:1669–1686.[Taylor & Francis Online], [Web Science ®] , [Google Scholar]]. Previous work some us has shown that thermoresponsive copolymers...