hydrogel

Driving water cavitation into a hydrogel cavity

We study the dynamics of the dehydration process of a hydrogel with a cavity filled with water. We identify two transient phases: the first one dominated by an inflatable-balloon deformation mode, and the second by a suction effect, determining highly not homogeneous deformation modes of the hydrogel walls. This last phase triggers negative pressures into the cavity up to the typical values of water cavitation. An analysis of the factors allowing cavitation pressure to form inside the cavity is proposed, to allow for precise tuning of the key geometrical and material parameters.

Biosynthesis of innovative calcium phosphate/hydrogel composites. Physicochemical and biological characterisation

The goal of supporting and directing tissue regeneration requires the design of new, advanced materials, with features like biocompatibility, biodegradability and adequate mechanical properties. Our work was focused on developing a new injectable biomimetic composite material, based on a peptidic hydrogel and calcium phosphates with the aim of mimicking the chemical composition of natural bone tissue. Arg-Gly-Asp-grafted chitosan was used to promote cell adhesion.

Pre-medicated gauze with hydrogel and hydrolat of Citrus aurantium var amara (flowers) for the prevention of microbial infections of the damaged skin

As known, one of the major problems linked to the wound care is the highest probability of infection. Until now, many studies have been developed to modify gauzes made with hydrogel, with the only function to make the wound moist, giving it also an antimicrobial action. However, articles published to date show gauzes modified with the addition of antibiotics or chemical compounds with antimicrobial action or at most essential oils like Melaleuca alternifolia (Tea Tree Oil).

Design of hybrid gels based on gellan-cholesterol derivative and P90G liposomes for drug depot applications

Gels are extensively studied in the drug delivery field because of their potential benefits in therapeutics. Depot gel systems fall in this area, and the interest in their development has been focused on long-lasting, biocompatible, and resorbable delivery devices. The present work describes a new class of hybrid gels that stem from the interaction between liposomes based on P90G phospholipid and the cholesterol derivative of the polysaccharide gellan.

C-12 vs C-3 substituted bile salts: an example of the effects of substituent position and orientation on the self-assembly of steroid surfactant isomers

Biomolecule derivatives are transversally used in nanotechnology. Deciphering their aggregation behavior is a crucial issue for the rational design of functional materials. To this end, it is necessary to build libraries of selectively functionalized analogues and infer general rules. In this work we enrich the highly applicative oriented collection of steroid derivatives, by reporting a rare example of C-12 selectively modified bile salt. While nature often exploits such position to encode functions, it is unusual and not trivial to prepare similar analogues in the laboratory.

Polymorphic self-organization of Lauroyl peptide in response to pH and concentration

Amphipathic peptides are attractive building blocks for the preparation of self-assembling, bio-inspired, and stimuli responsive nanomaterials with pharmaceutical interest. The bioavailability of these materials can be improved with the insertion of d amino acid residues to avoid fast proteolysis in vivo. With this knowledge, a new lauroyl peptide consisting of a sequence of glycine, glycine, d-serine, and d-lysine was designed. In spite of its simple sequence, this lipopeptide self-assembles into spherical micelles at acid pH, when the peptide moiety adopts disordered conformations.

A physico-chemical approach to the study of genipin crosslinking of biofabricated peptide hydrogels

Peptide-based hydrogels have been widely used for both tissue engineering approaches and therapeutic drug delivery mainly thanks to their tissue-like water content and tunable physicochemical properties. In particular, the modulation of the hydrogel chemical structure influences hydrogel properties. The most common approach for tuning hydrogel properties in terms of cell adhesion or release efficiency of entrapped compounds is chemical crosslinking.

Hydration of hydrogels studied by near-infrared hyperspectral imaging

Hydrogels are an important class of biomaterials that can absorb large quantities of water. In this study, changes in hydration of natural hydrogels (agar, chitosan, gelatin, starch, and blends of each with chitosan) during storage and rehydration were studied by using near-infrared hyperspectral imaging (NIR-HSI). Moisture content was calculated based on changes in sample weight during hydration. The NIR-HSI data were acquired by using a push-broom system operating in diffuse reflectance in the wavelength range 943 to 1650 nm.

Biosynthesis and characterization of a novel Fmoc-tetrapeptide based hydrogel for biotechnological applications

The applications of peptide-based materials are currently expanding, especially in the biomedical field. The biocompatibility and biodegradability of peptide materials, as well as their ability to assemble into ordered secondary structures, are indeed ideal for biotechnological applications. However, their full potential will be exploited once novel synthetic procedures are developed for advanced applications. In this work, we explored the ability of Pseudomonas fluorescens lipase to biosynthesize the self-assembled tetrapeptide FmocPheGlyPhe2 for tissue regeneration.

FBG multifunctional pH sensor - Monitoring the pH rain in cultural heritage

A new era of pollution requires an important focus on the conservation of archaeological sites and monuments. In the last years great efforts were required to develop various sensors for different tasks. The fiber Bragg grating (FBG) was one of the most studied thanks to the multitude of applications and the surprising performances. An original fiber optic sensor that combines the fiber Bragg gratings with a pH-responsive polymer coating for monitoring the pH of the rains on critical and prestigious monuments is proposed.

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