Thermo‐responsive hydrogels from cellulose‐based polyelectrolytes and catanionic vesicles for biomedical application

Abstract

In this study, negatively charged catanionic vesicles/hydrophobically modified hydroxyethylcellulose polymers thermo-responsive hydrogels have been fabricated. Vesicular aggregates were found to act as multifunctional junctions for networking of modified-cellulose water solutions. The contributions of the electrostatic and hydrophobic interactions were evaluated by changing either vesicles composition or the polymer hydrophobic substitution. Thermal-induced size and lamellarity of hydrogel-enclosed vesicles were detected, with further polygonal shape changes induced by cellulose-based polymer addition. The thermal transition was also found to tune hydrogel mechanical behaviour. The network formation was further assessed through molecular insights, which allow to determine the arrangement of the polymer chains on the vesicles' surface. The examined systems exhibited interesting thermo-responsive characteristics. Thus, vesicularly cross-linked hydrogels herein presented can offer a wide variety of applications, i.e. in biomedical field, as multi-drug delivery systems, thanks to their ability to provide for different environments to guest molecules, comprising bulk water, vesicles' interior and bilayers, sites on polymeric chains. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 104A: 1668-1679, 2016.

Protease and DNase Activities of a Very Stable High-Molecular-Mass Multiprotein Complex from Sea Cucumber Eupentacta fraudatrix

“…Protease activity of the holothurian complex was measured by the simple standard method using azocasein as a substrate [ 15 ]. The reaction mixture (300 μL) contained 3.3 mg/mL azocasein and 20 mM Tris-HCl (pH 7.5) or other buffers with pH in the range of 5.5 to 10.0 and 0.025 mg/mL protein complex.…”

“…It was shown that the sea cucumber complex accumulates various elements, including those contained in very low concentrations in seawater. Some studies have shown that various metal ions can significantly affect the stability of complexes of very different nature, consisting of charged, hydrophobic and hydrophilic molecules [ 15 , 16 ], as well as proteins and nucleic acids [ 17 , 18 , 19 , 20 , 21 ]. The data indicate that metal-dependent interactions are formed, in addition to hydrogen bonds between the complex components [ 14 ].…”

Recent advances in smart biotechnology: Hydrogels and nanocarriers for tailored bioactive molecules depot

“…Thus, network meshes configure as a dynamic equilibrium, due to chains segments size and related Brownian motions, being the average mesh number and dimension constant [4,7]. Ordered zones formation is favored/hindered by environmental conditions such as temperature and ionic strength [8]. For instance, agarose undergoes a thermo-reversible gelation process occurring when hot solutions are cooled below~40°C.…”

Theoretical Evaluation of the Interactions between Metal-Phthalocyanines and Various Fullerenes as Delivery Systems

“…Drug delivery systems with adjustable properties have the ability to host a variety of molecules. For example, vesicularly cross-linked hydrogels are able to provide different environments for pharmaceuticals comprising bulk water, sites on polymeric chains, the interior of vesicles, and bilayers [14]. Most phthalocyanines are hydrophobic compounds that require association with other drug delivery systems.…”