Functional Groups Of Gelatin Research Articles

The Effects of Citric Acid Crosslinking on Fabrication and Characterization of Gelatin/Curcumin-Based Electrospun Antioxidant Nanofibers.

Nanofibers, produced through the novel method of electrospinning, have a high ratio of surface area to volume, which allows them to have different optical, electrical, thermal, and mechanical properties than macroscale materials. In this study, it was aimed to produce nanofibers with gelatin and curcumin. The effects of gelatin concentration and crosslinking with citric acid on the characteristics of electrospun nanofibers were studied. Gelatin film containing neither citric acid nor curcumin was used as control. Solutions were evaluated by solution conductivity, color analysis, and rheological properties. Obtained nanofibers were characterized by morphological analysis (SEM), antioxidant activity (AA), thermal properties (TGA, XRD, DSC), water vapor permeability (WVP), and Fourier transform infrared (FTIR) analysis. It was found that the functional groups of gelatin were not changed significantly but some degree of crosslinking was seen, as indicated by the changes in AA, crystallinity, etc. Improvement in antioxidant activities was seen, which was the highest for gelatin and curcumin films (32%). The highest melting temperature (78 °C) and WVP (2.365 × 10-10 gm-1 s-1 Pa-1) was seen for gelatin and curcumin films crosslinked with 0.5% citric acid. Gelatin with curcumin films crosslinked with 1% citric acid showed the lowest crystallinity (1.56%). It was concluded that even though citric acid might not prove to be a stable crosslinking agent for the protein (gelatin), it contributed to the antioxidant nature of the films, along with curcumin. These films are promising candidates to be applied on cut fruits, to reduce water loss and oxidation and hence extend their shelf lives.

Designing Viscoelastic Gelatin-PEG Macroporous Hybrid Hydrogel with Anisotropic Morphology and Mechanical Properties for Tissue Engineering Application

The mechanical properties of scaffolds play a vital role in regulating key cellular processes in tissue development and regeneration in the field of tissue engineering. Recently, scaffolding material design strategies leverage viscoelasticity to guide stem cells toward specific tissue regeneration. Herein, we designed and developed a viscoelastic Gel-PEG hybrid hydrogel with anisotropic morphology and mechanical properties using a gelatin and functionalized PEG (as a crosslinker) under a benign condition for tissue engineering application. The chemical crosslinking/grafting reaction was mainly involved between epoxide groups of PEG and available functional groups of gelatin. FTIR spectra revealed the hybrid nature of Gel-PEG hydrogel. The hybrid hydrogel showed good swelling behavior (water content > 600%), high porosity and pore interconnectivity suitable for tissue engineering application. Simple unidirectional freezing followed by a freeze-drying technique allowed the creation of structurally stable 3D anisotropic macroporous architecture that showed tissue-like elasticity and was capable of withstanding high deformation (50% strain) without being damaged. The tensile and compressive modulus of Gel-PEG hybrid hydrogel were found to be 0.863 MPa and 0.330 MPa, respectively, which are within the range of normal human articular cartilage. In-depth mechanical characterizations showed that the Gel-PEG hybrid hydrogel possessed natural-tissue-like mechanics such as non-linear and J-shaped stress-strain curves, stress softening effect, high fatigue resistance and stress relaxation response. A month-long hydrolytic degradation test revealed that the hydrogel gradually degraded in a homogeneous manner over time but maintained its structural stability and anisotropic mechanics. Overall, all these interesting features provide a potential opportunity for Gel-PEG hybrid hydrogel as a scaffold in a wide range of tissue engineering applications.

Effect of gelatinous spongy scaffold containing nano-hydroxyapatite on the induction of odontogenic activity of dental pulp stem cells

Tissue engineering methods may be applied for the repair or regeneration of damaged teeth by inducing cell proliferation and differentiation in endodontic regeneration. One of the main factors in tissue engineering is the scaffold used. An ideal scaffold should be able to facilitate predictable tissue development in endodontic regeneration. Thus, tissue engineering requires consideration for the composition and functionality of the scaffold suited for biological applications. The objective of this study was to assess the morphological, physico-chemical, and biological properties of a new gelatin (Gel)-nano-hydroxyapatite (nHA)-based scaffold to be applied in endodontic regeneration. The scaffold containing gelatin and nHA was prepared by a freeze-drying method. Conventional techniques, including scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FT-IR), X-ray diffraction analysis (XRD), and dynamic light scattering (DLS) analysis were used to evaluate the physico-chemical properties of the fabricated Gel-nHA sponge scaffold. Biological examination for cell survival and differentiation of dental pulp stem cells (DPSCs) was evaluated by the MTT assay and ALP activity techniques, respectively. The produced Gel-nHA scaffold had spongy properties that all functional groups of gelatin and hydroxyapatite were present in the sponge. In biological studies, the viability of the cells grown on Gel-nHA scaffold had no different change from the control group on days 2nd, 4th, and 6th. Besides, after 14 days of cells cultured on Gel-nHA, alkaline phosphatase (ALP) activity showed a significant increment. In summary, the Gel-nHA scaffold revealed favorable effects on odontogenic activity, implying a potential future for application in endodontic regeneration.

Facile Preparation of Antibacterial Gelatin-Kaolin Bionano- composite Membranes and Study of Water Sorption and Water Vapour Transmission Rate (WVTR)

Glutaraldehyde crosslinked gelatin kaolin bionanocomposite films were prepared by casting method and characterized by various techniques and water vapour transmission rates and water sorption studies were performed. The FTIR study revealed the interaction between functional groups of gelatin and kaolin evidenced by shifting of some spectral peaks. The grain size of bionanocomposite films was calculated to be 29 nm from XRD analysis and the crystallinity was 62 %. The SEM and AFM analysis suggested for heterogeneous surfaces having pores and pits. The glass transition temperature of gelatin film was found to increase from 70 to 100°C as revealed by DSC technique. The thermal properties increased with increasing kaolin. The addition of kaolin marked an increase in Young’s modulus and tensile strength. The bionanocomposite films showed a fall in water sorption capacity with increasing kaolin content. The water vapour transmission rate (WVTR) decreased with increasing addition of kaolin. The films were found to show antibacterial nature against Aureus.

Anti‐Bacterial Hydrogels: A Hydrogen‐Bonded Extracellular Matrix‐Mimicking Bactericidal Hydrogel with Radical Scavenging and Hemostatic Function for pH‐Responsive Wound Healing Acceleration (Adv. Healthcare Mater. 3/2021)

Extracellular matrix-mimicking hydrogels with antioxidant, hemostasis, and antibacterial properties offer translating avenues towards wound repair through the promotion of fibroblast proliferation. In article number 2001122 by Hélder A. Santos, Mohammad-Ali Shahbazi, and co-workers, hydrogen bonding among the functional groups of gelatin and tannic acid creates a biocompatible hydrogel, where the improvement of re-epithelialization and collagen deposition are its main features to treat full-thickness wounds.

A Hydrogen-Bonded Extracellular Matrix-Mimicking Bactericidal Hydrogel with Radical Scavenging and Hemostatic Function for pH-Responsive Wound Healing Acceleration.

Generation of reactive oxygen species, delayed blood clotting, prolonged inflammation, bacterial infection, and slow cell proliferation are the main challenges of effective wound repair. Herein, a multifunctional extracellular matrix-mimicking hydrogel is fabricated through abundant hydrogen bonding among the functional groups of gelatin and tannic acid (TA) as a green chemistry approach. The hydrogel shows adjustable physicochemical properties by altering the concentration of TA and it represents high safety features both in vitro and in vivo on fibroblasts, red blood cells, and mice organs. In addition to the merit of facile encapsulation of cell proliferation-inducing hydrophilic drugs, accelerated healing of skin injury is obtained through pH-dependent release of TA and its multifaceted mechanisms as an antibacterial, antioxidant, hemostatic, and anti-inflammatory moiety. The developed gelatin-TA (GelTA) hydrogel also shows an outstanding effect on the formation of extracellular matrix and wound closure in vivo via offered cell adhesion sites in the backbone of gelatin that provide increased re-epithelialization and better collagen deposition. These results suggest that the multifunctional GelTA hydrogel is a promising candidate for the clinical treatment of full-thickness wounds and further development of wound dressing materials that releases active agents in the neutral or slightly basic environment of infected nonhealing wounds.

Physical and Chemical Properties of Gelatin from Red Snapper Scales : Temperature Effects

The extent of applications in various fields makes the need for gelatin continue to increase in the global market. Fish gelatin is an alternative to mammalian gelatin and its use is more universal because it can be consumed by all religious followers. The high variability of fish gelatin properties is caused by the availability of many extraction methods to obtain it. This preliminary study was carried out to find the optimum range of gelatin extraction procedures using Red Snapper scales because it had not been widely studied, although it was reported that gelatin yield was not significantly different from the bone and skin part. The optimum condition of the extraction procedure was obtained by pre-treatment using 5 % CH3COOH with extraction temperature of 60 °C which produces 58.19% swelling of fish scales and yield of gelatin is 8.76% with the moisture quality of 6.68%, pH of 6.225, viscosity of 15.54 cP and the melting point of 60 °C. The functional groups of gelatin was also successfully confirmed by FT-IR spectra.

Rational Design and Development of Anisotropic and Mechanically Strong Gelatin-Based Stress Relaxing Hydrogels for Osteogenic/Chondrogenic Differentiation.

Rational design and development of tailorable simple synthesis process remains a centerpiece of investigational efforts toward engineering advanced hydrogels. In this study, a green and scalable synthesis approach is developed to formulate a set of gelatin-based macroporous hybrid hydrogels. This approach consists of four sequential steps starting from liquid-phase pre-crosslinking/grafting, unidirectional freezing, freeze-drying, and finally post-curing process. The chemical crosslinking mainly involves between epoxy groups of functionalized polyethylene glycol and functional groups of gelatin both in liquid and solid state. Importantly, this approach allows to accommodate different polymers, chitosan or hydroxyethyl cellulose, under identical benign condition. Structural and mechanical anisotropy can be tuned by the selection of polymer constituents. Overall, all hydrogels show suitable structural stability, good swellability, high porosity and pore interconnectivity, and maintenance of mechanical integrity during 3-week-long hydrolytic degradation. Under compression, hydrogels exhibit robust mechanical properties with nonlinear elasticity and stress-relaxation behavior and show no sign of mechanical failure under repeated compression at 50% deformation. Biological experiment with human bone marrow mesenchymal stromal cells (hMSCs) reveals that hydrogels are biocompatible, and their physicomechanical properties are suitable to support cells growth, and osteogenic/chondrogenic differentiation, demonstrating their potential application for bone and cartilage regenerative medicine toward clinically relevant endpoints.

Fabrication and preliminary in vitro evaluation of ultraviolet-crosslinked electrospun fish scale gelatin nanofibrous scaffolds.

This study aimed to explore a potential use of fish scale-derived gelatin nanofibrous scaffolds (GNS) in tissue engineering due to their biological and economical merits. Extraction of gelatin was achieved via decalcification, sonication and lyophilization of mixed fish scales. To fabricate nano-scale architecture of scaffolds analogous to natural extracellular matrix, gelatin was rendered into nanofibrous matrices through 6-h electrospinning, resulting in the average diameter of 48 ± 12 nm. In order to improve the water-resistant ability while retaining their biocompatibility, GNS were physically crosslinked with ultraviolet (UV) irradiation for 5 min (UGN5), 10 min (UGN10) and 20 min (UGN20). On average, the diameter of nanofibers increased by 3 folds after crosslinking, however, Fourier transform infrared spectroscopy analysis confirmed that no major alterations occurred in the functional groups of gelatin. A degradation assay showed that UGN5 and UGN10 scaffolds remained in minimum essential medium for 14 days, while UGN20 scaffolds degraded completely after 10 days. All UGN scaffolds promoted adhesion and proliferation of human keratinocytes, HaCaT, without causing an apparent cytotoxicity. UGN5 scaffolds were shown to stimulate a better growth of HaCaT cells compared to other scaffolds upon 1 day of incubation, whereas UGN20 had a long-term effect on cells exhibiting 25% higher cell proliferation than positive control after 7 days. In the wound scratch assay, UGN5 scaffolds induced a rapid cell migration closing up to 79% of an artificial wound within 24 h. The current findings provide a new insight of UGN scaffolds to serve as wound dressings in the future. In the wound scratch assay, UGN5 induced a rapid cell migration closing up to 79% of an artificial wound within 24 h.

EFFECT OF GARLIC POWDER ADDITION TO GELATIN BIOCOMPOSITE ON ITS ANTIBACTERIAL ACTIVITY

<p>The addition of garlic powder to gelatin from chicken claw waste was potentially developed as a natural preservative in food, especially for meat. Preparation of gelatin/garlic biocomposite was performed in three stages: synthesis of gelatin from chicken claw, garlic powder preparation as allicin source and preparation of biocomposite gelatin/garlic. The preparation of dry biocomposites was done by weighing the gelatin and garlic powder in weight ratio of 1 : 1 and 1 : 2 (w/w) in the total mass of 0.75 grams. For wet biocomposite preparation, the mixture of the powder was solved in 5 mL of lactic acid 2 %. Functional groups of gelatin, garlic and biocomposite were analyzed by <em>f</em><em>ourier transform infrared spectroscopy</em> (FTIR). The antibacterial activity of biocomposite against <em>Staphylococcus aureus</em> were tested using disc diffusion method. This test was performed on garlic powder, solvent and gelatin/garlic biocomposites powder in the ratio of 1 : 1 and 1 : 2 in 2 % lactic acid solvent. The biocomposite with a weight ratio of gelatin : garlic of 1 : 1 had the optimum diameter of inhibition zone. The effectiveness of biocomposite gelatin/garlic as natural preservative applied in meat was also physically studied by organoleptic analysis. Organoleptic analysis through the hedonic test was conducted on the parameters of color, smell, and texture of gelatin/garlic biocomposites-coated meat. The results showed that the addition of garlic can increase the effectiveness of gelatin as a natural preservative of meat for four days stored in closed packaging at room temperature.</p>

EFFECT OF GARLIC POWDER ADDITION TO GELATIN BIOCOMPOSITE ON ITS ANTIBACTERIAL ACTIVITY

<p>The addition of garlic powder to gelatin from chicken claw waste was potentially developed as a natural preservative in food, especially for meat. Preparation of gelatin/garlic biocomposite was performed in three stages: synthesis of gelatin from chicken claw, garlic powder preparation as allicin source and preparation of biocomposite gelatin/garlic. The preparation of dry biocomposites was done by weighing the gelatin and garlic powder in weight ratio of 1 : 1 and 1 : 2 (w/w) in the total mass of 0.75 grams. For wet biocomposite preparation, the mixture of the powder was solved in 5 mL of lactic acid 2 %. Functional groups of gelatin, garlic and biocomposite were analyzed by <em>f</em><em>ourier transform infrared spectroscopy</em> (FTIR). The antibacterial activity of biocomposite against <em>Staphylococcus aureus</em> were tested using disc diffusion method. This test was performed on garlic powder, solvent and gelatin/garlic biocomposites powder in the ratio of 1 : 1 and 1 : 2 in 2 % lactic acid solvent. The biocomposite with a weight ratio of gelatin : garlic of 1 : 1 had the optimum diameter of inhibition zone. The effectiveness of biocomposite gelatin/garlic as natural preservative applied in meat was also physically studied by organoleptic analysis. Organoleptic analysis through the hedonic test was conducted on the parameters of color, smell, and texture of gelatin/garlic biocomposites-coated meat. The results showed that the addition of garlic can increase the effectiveness of gelatin as a natural preservative of meat for four days stored in closed packaging at room temperature.</p>

EFFECT OF GARLIC POWDER ADDITION TO GELATIN BIOCOMPOSITE ON ITS ANTIBACTERIAL ACTIVITY

The addition of garlic powder to gelatin from chicken claw waste was potentially developed as a natural preservative in food, especially for meat. Preparation of gelatin/garlic biocomposite was performed in three stages: synthesis of gelatin from chicken claw, garlic powder preparation as allicin source and preparation of biocomposite gelatin/garlic. The preparation of dry biocomposites was done by weighing the gelatin and garlic powder in weight ratio of 1 : 1 and 1 : 2 (w/w) in the total mass of 0.75 grams. For wet biocomposite preparation, the mixture of the powder was solved in 5 mL of lactic acid 2 %. Functional groups of gelatin, garlic and biocomposite were analyzed by <em>f</em><em>ourier transform infrared spectroscopy</em> (FTIR). The antibacterial activity of biocomposite against <em>Staphylococcus aureus</em> were tested using disc diffusion method. This test was performed on garlic powder, solvent and gelatin/garlic biocomposites powder in the ratio of 1 : 1 and 1 : 2 in 2 % lactic acid solvent. The biocomposite with a weight ratio of gelatin : garlic of 1 : 1 had the optimum diameter of inhibition zone. The effectiveness of biocomposite gelatin/garlic as natural preservative applied in meat was also physically studied by organoleptic analysis. Organoleptic analysis through the hedonic test was conducted on the parameters of color, smell, and texture of gelatin/garlic biocomposites-coated meat. The results showed that the addition of garlic can increase the effectiveness of gelatin as a natural preservative of meat for four days stored in closed packaging at room temperature.

The Production of Gelatin-Calcium Carbonate Composite Films with Different Antioxidants

Gelatin-calcium carbonate films incorporated with different natural antioxidants (sodium ascorbate, d-sodium erythorbate, and tea polyphenols) were investigated in this study. The results indicated that all of the films with antioxidants displayed promoted tensile strength and higher thickness than that of the control (p < 0.05), and most films had higher values of elongation at break. Furthermore, the addition of antioxidants favored the reduction of water vapor permeability and water solubility in comparison with the control (p < 0.05). The alternations of light transmission could vary depending on the type and concentration of antioxidants. In addition, the surface properties of films were characterized by atomic force microscopy, indicating that antioxidants caused the formation of gelatin-calcium carbonate aggregates and clusters. Moreover, Fourier transform infrared spectroscopy spectra demonstrated that antioxidants facilitated the conformational changes of the secondary structure and functional groups of gelatin in films. Gelatin-calcium carbonate films containing different natural antioxidants exhibited improved 2, 2-diphenyl-1-picryl hydrazyl radical scavenging capacities, compared to the control (p < 0.05).

Fe(CN)6]4− decorated mesoporous gelatin thin films for colorimetric detection and as sorbents of heavy metal ions

[Fe(CN)6](4-) decorated mesoporous gelatin films, acting as colorimetric sensors and sorbents for heavy metal ions, were prepared by incorporating [Fe(CN)6](4-) ions into the mesoporous gelatin films through electrostatic interaction. Gelatin-Prussian blue (PB) and gelatin-PB analogue composite films were successfully synthesized by immersing the [Fe(CN)6](4-) decorated gelatin films into aqueous solutions of metal ions, such as Fe(3+), Cu(2+), Co(2+), Pb(2+) and Cd(2+) (all as nitrates). The in situ formation process of PB or its analogues in the films was investigated using quartz crystal microbalance (QCM) measurements. According to the different colors of the PB nanoparticles and its analogues, the [Fe(CN)6](4-) decorated mesoporous gelatin films demonstrated colorimetric sensor abilities for detecting the corresponding metal ions by the naked eye with sufficient sensitivity at 1 ppm level and a quite short response time of 5 minutes. Moreover, due to the [Fe(CN)6](4-) functionality and other functional groups of gelatin itself, this [Fe(CN)6](4-) decorated mesoporous gelatin film shows a tens times higher adsorption ability for heavy metal ions in water than that of activated carbon. Due to both the efficient detection and high adsorption ability for heavy metal ions, this film has wide potential applications for the detection and purification of heavy metal ions from polluted water.

Study of cross-linking of gelatin by ethylene glycol diglycidyl ether

Type-B gelatin prepared at 13 wt.% with respect to a buffer solution was cross-linked by using additions of 1–15 wt.% of ethylene glycol diglycidyl ether (EGDE) at pH levels ranging from 7.4 to 11. The cross-linking reaction was studied by measuring the swelling ratio, FT-IR, and 13C NMR analysis. The amine (NH 2) functional groups of gelatin were totally consumed by 10 wt.% EGDE. For 3 wt.% EGDE or more, the swelling ratio decreased when the pH was increased from 7.4 to 9. This tendency was inverted at pH > 9, possibly due to a denaturation of gelatin as well as a negative interference from an excessive amount of OH − ions in the cross-linking reaction.

A study of adsorption of a cyanine dye to cubic AgBr microcrystals suspended in a dried gelatin layer

The amount of a cyanine dye [3,3′-bis(4-sulfobutyl)-9-methylthiacarbocyanine] adsorbed to cubic AgBr microcrystals m suspended in dried gelatin (i.e., dried emulsion) was measured by preparing dried emulsion layers, which were smooth and thick enough for treatment by the Kubelka–Munk equation and gave useful information on the adsorption of the dye and materials of photographic interests to the microcrystals. The saturated amount of the adsorbed dye M in a dried emulsion layer was smaller than that in a liquid emulsion, since functional groups of gelatin and a stabilizer (4-hydroxy-6-methyl-1,3,3a,7-tetraazaindene) in the solution phase of the liquid emulsion were forced to be adsorbed to the microcrystals on drying. The dye adsorption increased the concentration of interstitial silver ions in the microcrystals by repelling silver ions at kink sites on the surface of the microcrystals into interstitial positions, especially when m approached M. The number of silver ions repelled into interstitial positions was less than 0.001 of that of the dye molecules adsorbed to the microcrystals.

An Investigation of the Role of the Functional Groups of Gelatin on Silver Halide Crystal Growth

AbstractThe increase in the mean panicle size of a dispersion of silver halide microcrystals can be governerd either by recrystallization processes or by coagulation. The properties of the crystal surfaces due to adsorption phenomena as well as the electrochemical properties of the protective colloid molecules determine which particular mechanism of crystal growth predominates, as has been found by turbidimetric investigations.