New Gelatin-Based Hydrogels via Enzymatic Networking (original) (raw)

Synthesis and Characterization of Hybrid Hyaluronic Acid-Gelatin Hydrogels

Biomacromolecules, 2013

Biomimetic hybrid hydrogels have generated broad interest in tissue engineering and regenerative medicine. Hyaluronic acid (HA) and gelatin (hydrolyzed collagen) are naturally derived polymers and biodegradable under physiological conditions. Moreover, collagen and HA are major components of the extracellular matrix (ECM) in most of the tissues (e.g. cardiovascular, cartilage, neural). When used as a hybrid material, HA-gelatin hydrogels may enable mimicking the ECM of native tissues. Although HA-gelatin hybrid hydrogels are promising biomimetic substrates, their material properties have not been thoroughly characterized in the literature. Herein, we generated hybrid hydrogels with tunable physical and biological properties by using different concentrations of HA and gelatin. The physical properties of the fabricated hydrogels including swelling ratio, degradation, and mechanical properties were investigated. In addition, in vitro cellular responses in both two and three dimensional (2D and 3D) culture conditions were assessed. It was found that the addition of gelatin methacrylate (GelMA) into HA methacrylate (HAMA) promoted cell spreading in the hybrid hydogels. Moreover, the hybrid hydrogels showed significantly improved mechanical properties compared to their single component analogs. The HAMA-GelMA hydrogels exhibited remarkable tunability behavior and may be useful for cardiovascular tissue engineering applications.

New Hydrogels Based on Gelatin and Acrylamide

2013

The study presents the synthesis and characterization of bicomponent polymer systems based on modified gelatin and polyacrylamide in the aim of obtaining materials with superior properties with respect to the individual components. The synthesis of the hydrogels was carried out through the polymerization of C=C groups of the synthetic monomer and of the modified gelatin using photoinitiation. Five bicomponent systems with different ratios between the individual components have been obtained, using methacrylamide modified gelatin of two different substitution degrees. Subsequently, the materials have been characterized in order to establish the relationship composition-properties.

Rheological Properties of Cross-Linked Hyaluronan-Gelatin Hydrogels for Tissue Engineering

Macromolecular Bioscience, 2009

Hydrogels that mimic the natural extracellular matrix (ECM) are used in three-dimensional cell culture, cell therapy, and tissue engineering. A semi-synthetic ECM based on cross-linked hyaluronana offers experimental control of both composition and gel stiffness. The mechanical properties of the ECM in part determine the ultimate cell phenotype. We now describe a rheological study of synthetic ECM hydrogels with storage shear moduli that span three orders of magnitude, from 11 to 3 500 Pa, a range important for engineering of soft tissues. The concentration of the chemically modified HA and the cross-linking density were the main determinants of gel stiffness. Increase in the ratio of thiol-modified gelatin reduced gel stiffness by diluting the effective concentration of the HA component.

Hydrogels prepared by crosslinking of gelatin with dextran dialdehyde

Reactive and Functional Polymers, 1997

Hydrogels were prepared by reaction of gelatin with partial periodate oxidized dextran. It was found that the rate of gelation depends on the molecular weight and on the degree of oxidation of dextran, the type of gelatin and on the reaction conditions. Rheological measurements demonstrate that the gel strength is governed by two factors: chemical crosslinking by reaction with polyaldehyde and physical structuring of the gelatin. By proper selection of the reaction conditions, in particular storage temperature, the contribution of both processes to the final material strength can be varied. It was observed that short cryogenic treatment significantly enhances the chemical crosslinking.

Effect of Initiator's Concentration on Properties of Gelatin - Hema Hydrogels

2012

Acest studiu descrie sinteza de sisteme polimerice bicomponente, pe bază de gelatină şi polimeri 2-hidroxietil metacrilat. Sintezele s-au realizat prin procese combinate de polimerizare şi reticulare folosind fotoiniţierea. S-au sintetizat trei tipuri de hidrogeluri, folosind diferite concentraţii de fotoiniţiator. Succesul sintezei şi influenţa compoziţiei asupra proprietăţilor metarialelor au fost evaluate prin diferite metode de caracterizare; a fost determinată compoziţia optimă. Ulterior au fost realizate structuri poroase prin tratament criogenic şi liofilizare. S-a realizat o caracterizare morfologică a materialelor poroase, care a demonstrat faptul că arhitectura materialelor este puternic influenţată de compoziia lor. The present work describes the synthesis of bicomponent polymer systems based on gelatin and also on 2-hydroxyethyl methacrylate polymers. The syntheses were performed through a combined process of cross-linking polymerization while using photoinitiation. Three types of hydrogels have been synthesised using different photoinitiator concentrations. The success of the syntheses and the influence of the compositions on properties of the materials, were assessed through various characterization methods; optimal composition was determined. Subsequently, porous structures have been obtained by cryogenic treatment and freeze-drying. A morphological characterization of the scaffolds was subsequently performed, showing that the architecture of the scaffolds was strongly influenced by the composition of the materials.

Ionically and covalently crosslinked hydrogels based on gelatin and chitosan

Soft Materials, 2011

The formation of double cross-linked (ionic and covalent) gelatin (G) and chitosan (CS) hydrogels was studied. The covalent cross-linking consists in the reaction between the carbonyl groups of glutaraldehyde with the free amine groups from the two polymers; the ionic cross-linking is based on sulfate anions interaction with protonated amine groups of the polymers solubilized in acetic acid. The structural and morphological characterization of the obtained hydrogels was performed using FT-IR and scanning electron microscopy (SEM).The influence of different parameters on the cross-linking density (indirectly assessed by water swelling capacity) and the ability to include hydrosoluble active principles such as the ratio between polymers (G/CS), the amount of ionic cross-linker, and the cross-linking time were investigated.The morphological and structural characteristics, mechanical stability, elasticity of the network, the interaction with aqueous weak alkaline solutions, and the capacity to load and release a model drug were analyzed for the obtained hydrogels. Rheological tests were performed to study the mechanical stability of the hydrogels and the results show, generally, elastic and stable networks.

Hyaluronic Acid Hydrogels Formed in Situ by Transglutaminase-Catalyzed Reaction

Biomacromolecules, 2016

Enzymatically cross-linked hydrogels can be formed in situ and permit highly versatile and selective tethering of bioactive molecules, thereby allowing for a wealth of applications in cell biology and tissue engineering. While a number of studies have reported the bioconjugation of extracellular matrix (ECM) proteins and peptides into such matrices, the sitespecific incorporation of biologically highly relevant polysaccharides such as hyaluronic acid (HA) has thus far not been reported, limiting our ability to reconstruct this key feature of the in vivo ECM. Here we demonstrate a novel strategy for transglutaminase-mediated covalent linking of HA moieties to a synthetic poly(ethylene glycol) (PEG) macromer resulting in the formation of hybrid HA-PEG hydrogels. We characterize the ensuing matrix properties and demonstrate how these cytocompatible gels can serve to modulate the cellular phenotype of human mammary cancer epithelial cells as well as mouse myoblasts. The use of HA as a novel building block in the increasingly varied library of synthetic PEG-based artificial ECMs should have applications as a structural as well as a signaling component and offers significant potential as an injectable matrix for regenerative medicine.

Characterization of gelatin hydrogels derived from different animal sources

Materials Letters, 2020

Gelatin hydrogels are a valid alternative to produce scaffolds, wound dressings, and drug delivery systems. However, the animal source from which collagen is extracted to obtain gelatin and its treatment are often underestimated despite they can influence the properties of the obtained gelatin hydrogels. Here, three gelatin powders derived from different animal sources (i.e., porcine, bovine and cold water fish) are chemically crosslinked by two reactions and their physico-mechanical properties investigated. The noncytotoxic hydrogels swelled differently in water (i.e., porcine > fish > bovine), which in turn influenced the mechanical properties of the obtained hydrogels, highlighting the importance of properly selecting the gelatin source when preparing gelatin hydrogels.

A Comprehensive Review on Hydrogels

International Journal of Current Pharmaceutical Research, 2016

Polymers play a vital role in pharmaceutical development. Efforts have been continuously made to search a polymer that act in a controlled& desired way. Hydrogel development has solved many such issues. Hydrogels are hydrophilic, three-dimensional networks. Which are able to imbibe large amounts of water or biological fluids & thus resembles to a large extent, a biological tissue. They are insoluble due to the presence of physical or chemical crosslinks such as entanglements& crystallites. These materials can be synthesized to respond to a number of physiological stimuli present in the body, such as PH, ionic strength, temperature. The main aim of this article is to give a concise review on introduction, preparation methods, types, & various applications of hydrogels in the pharmaceutical field. Keywords: Hydrogels, Types of hydrogels, Preparation methods, Applications.