Gelatin Molecules Research Articles

Role and function of gelatin in the development of the food and non-food industry: A review

Gelatin is a product of the partial hydrolysis of collagen in livestock. Gelatin has been used extensively in the food and non-food industries. Gelatin has a hydrocolloid form and plays an important role in influencing the properties of industrial products. Global gelatin demands is increasing every year along with the increasing human need for food and non-food industrial products. The properties of gelatin are influenced by the properties of collagen. Collagen is a derivative of fibrous protein which has an enormous role and benefit in forming gelatin molecules. Collagen is a long polypeptide chain that makes up about 50 to 1000 amino acid chains. The amino acid chain is dominated by the amino acids glycine, proline and hydroxyproline. Various studies related to the properties of gelatin produced from livestock and fish tissues have developed rapidly. Currently researchers have developed livestock and fish waste as an alternative source of gelatin. Alternative sources of gelatin have been widely published as an effort to find halal and hygienic sources of gelatin.

Thermosensitive Chitosan-Gelatin-Glycerol Phosphate Hydrogels as Collagenase Carrier for Tendon-Bone Healing in a Rabbit Model.

Healing of an anterior cruciate ligament graft in bone tunnel yields weaker fibrous scar tissue, which may prolong an already prolonged healing process within the tendon–bone interface. In this study, gelatin molecules were added to thermosensitive chitosan/β-glycerol phosphate disodium salt hydrogels to form chitosan/gelatin/β-glycerol phosphate (C/G/GP) hydrogels, which were applied to 0.1 mg/mL collagenase carrier in the tendon–bone junction. New Zealand white rabbit’s long digital extensor tendon was detached and translated into a 2.5-mm diameter tibial plateau tunnel. Thirty-six rabbits underwent bilateral surgery and hydrogel injection treatment with and without collagenase. Histological analyses revealed early healing and more bone formation at the tendon–bone interface after collagenase partial digestion. The area of metachromasia significantly increased in both 4-week and 8-week groups after collagenase treatment (p < 0.01). Micro computed tomography showed a significant increase in total bone volume and bone volume/tissue volume in the 8 weeks after collagenase treatment, compared with the control group. Load-to-failure was significantly higher in the treated group at 8 weeks (23.8 ± 8.13 N vs 14.3 ± 3.9 N; p = 0.008). Treatment with collagenase digestion resulted in a 66% increase in pull-out strength. In conclusion, injection of C/G/GP hydrogel with collagenase improves tendon-to-bone healing in a rabbit model.

An Interpenetrating Alginate/Gelatin Network for Three-Dimensional (3D) Cell Cultures and Organ Bioprinting.

Crosslinking is an effective way to improve the physiochemical and biochemical properties of hydrogels. In this study, we describe an interpenetrating polymer network (IPN) of alginate/gelatin hydrogels (i.e., A-G-IPN) in which cells can be encapsulated for in vitro three-dimensional (3D) cultures and organ bioprinting. A double crosslinking model, i.e., using Ca2+ to crosslink alginate molecules and transglutaminase (TG) to crosslink gelatin molecules, is exploited to improve the physiochemical, such as water holding capacity, hardness and structural integrity, and biochemical properties, such as cytocompatibility, of the alginate/gelatin hydrogels. For the sake of convenience, the individual ionic (i.e., only treatment with Ca2+) or enzymatic (i.e., only treatment with TG) crosslinked alginate/gelatin hydrogels are referred as alginate-semi-IPN (i.e., A-semi-IPN) or gelatin-semi-IPN (i.e., G-semi-IPN), respectively. Tunable physiochemical and biochemical properties of the hydrogels have been obtained by changing the crosslinking sequences and polymer concentrations. Cytocompatibilities of the obtained hydrogels are evaluated through in vitro 3D cell cultures and bioprinting. The double crosslinked A-G-IPN hydrogel is a promising candidate for a wide range of biomedical applications, including bioartificial organ manufacturing, high-throughput drug screening, and pathological mechanism analyses.

Protein-Based Flexible Moisture-Induced Energy-Harvesting Devices As Self-Biased Electronic Sensors

Thin protein films of gelatin molecules grown on flexible substrates have been utilized to fabricate moisture-induced energy-harvesting devices, which work as self-biased sensors. Adsorbed water mo...

Hydrophobically-modified gelatin hydrogel as a carrier for charged hydrophilic drugs and hydrophobic drugs

Gelatin molecules have been chemically crosslinked using potentially cytotoxic reagents to prepare stable hydrogels. Hydrophobic interaction is a means of forming physical crosslinks that is a good candidate for enhancing the stability of gelatin hydrogels without using cytotoxic chemicals. In this study, we proposed a new method to fabricate hydrogels from hydrophobically-modified gelatin (HMG) with high content of hydrophobic segments. HMG was first dissolved in dimethyl sulfoxide and poured into a vial with the desired shape. After the solution was freeze-dried, the solid construct was hydrated. The HMG hydrogel containing basic fibroblast growth factor promoted angiogenesis in vivo, indicating that the positively charged hydrophilic growth factor formed an electrostatic complex with negatively charged HMG hydrogel and was gradually released in vivo with the degradation of the hydrogel. In addition, we showed that the hydrophobic segments of HMG enhanced the adsorption of fluorescein sodium, a model for hydrophobic therapeutic agents, to the hydrogel through hydrophobic interaction. Furthermore, in vitro experiments indicated that the hydrophobic agents would be released from the hydrogel in a controlled manner in vivo. These results show that the HMG hydrogel has significant potential as a carrier for both charged hydrophilic drugs and hydrophobic drugs.

Facile and scalable synthesis of nitrogen-doped ordered mesoporous carbon for high performance supercapacitors

Nitrogen-doped carbon has been receiving tremendous research interest due to its exotic electrochemical performance and catalyzing capability. Nevertheless, large-scale synthesis of ordered, mesoporous, nitrogen-doped carbon for supercapacitors is rarely reported due to the complexity and uncontrollable property of polymerization of carbon/nitrogen precursors. In this work, we report a facile and efficient approach for mass production of nitrogen-doped carbon, with a narrow pore size distribution and a sheet morphology, via a simple solution casting of biomass-based mixture. Upon drying, the gelatin molecules self-assemble into sheets, and guide the homogeneous loading of sacrificial silica nanospheres. Further carbonization and template removal procedures allow the low-cost production of nitrogen-doped carbon sheets in the absence of complex polymerization. As a result, nitrogen-doped carbon sheets possess a high nitrogen content and ordered, interconnected mesoporous channels, with porosity parameters being carbonization temperature and template size dependence. Additionally, nitrogen-doped, ordered carbon sheets exhibit high performance for supercapacitor application, including high specific capacitances and energy/power densities. This work demonstrates a unique route to synthesizing ordered mesoporous nitrogen-doped carbon sheets via a scalable, low-cost method, which may shed light on many other applications aside from energy storage, such as water splitting, catalysis and sensor.

Chemical and physical reinforcement of hydrophilic gelatin film with di-aldehyde nanocellulose

Gelatin is a representative hydrophilic protein material with remarkable biocompatibility and biodegradability. From the aspect of materials processing, gelatin also has the advantage that its entire fabrication process can be performed in an aqueous solution. However, practical application of various gelatin materials—in particular gelatin films—has thus far been limited because of their weak mechanical properties and vulnerability under aqueous environments. To overcome these disadvantages, both physical reinforcement approaches and chemical cross-linking agents have been tested. However, little research has been done to make these two roles work at the same time. In this study, cellulose nanocrystals containing aldehyde groups were prepared via a periodate oxidation process and used for cross-linkable reinforcement of gelatin-based bio-composite films. The results revealed that the di-aldehyde cellulose nanocrystal (D-CNC) could react and covalently cross-link with the amine group of the gelatin molecules via Schiff base formation and compared with neat CNC. The gelatin bio-composite film reinforced with the prepared D-CNC exhibited excellent tensile properties and water resistance, and its mechanical and hydrophilic properties could be easily controlled by adjusting the D-CNC content and was greater than addition of same amount in CNC. Therefore, D-CNC will facilitate the widespread use of existing water-soluble polymers, especially natural hydrophilic proteins and can be used in conventional application fields such as the food, pharmaceutical, and biomedical industries.

Development of surface functionalized hydroxyapatite nanoparticles for enhanced specificity towards tumor cells

Nanoparticles coupled with targeting moieties have attracted a great deal of attention for cancer therapy since they can facilitate site-specific delivery of drug and significantly limit the side effects of systemic chemotherapy. In this study, our aim is to develop surface functionalized hydroxyapatite nanoparticles, which could provide binding sites for a cancer cell targeting ligand, folic acid (FA) as well as an anticancer drug, doxorubicin hydrochloride (DOX). In order to attain dual functionalities, hydroxyapatite nanoparticles were functionalized with gelatin molecules. Gelatin, being a protein has both carboxyl and amine moieties, which makes it suitable for binding of DOX and FA. FA was chemically conjugated to the nanoparticles through an EDCNHS coupling reaction. The formation of single-phase hydroxyapatite nanostructure was ascertained by X-ray diffraction studies and the presence of organic moieties on the surface of nanoparticles was evident from Fourier transform infrared spectroscopy, thermogravimetric analysis and U.V.-visible spectroscopy. The FA-conjugated nanoparticles (FA-Gel-HANPs) showed high affinity towards DOX and pH-responsive sustained release of drug with higher release rate under acidic pH conditions, desired for cancer therapy. The FA-Gel-HANPs showed negligible cytotoxicity towards different cell lines (HepG2, WEHI-164, KB, WI-26 VA4 and WRL-68). However, DOX loaded nanoparticles (DOX-FA-Gel-HANPs) exhibited significant toxicity towards these cells, which was however highest in folate receptor (FR)-overexpressing, KB cells. These results were correlated with enhanced cellular uptake of DOX-FA-Gel-HANPs in KB cells in comparison to FR-deficient, WRL-68 cells studied by confocal laser scanning microscopy and flow cytometry. Moreover, cell cycle analysis in KB cells, showed higher sub-G1 population, indicating apoptosis as one of the cell death mechanisms. Overall, this study suggests that DOX-FA-Gel-HANPs could serve as a promising tumor-targeted drug delivery system.

Effects of γ-polyglutamic acid on the gelling properties and non-covalent interactions of fish gelatin.

The effects of γ-polyglutamic aid (γ-PGA) on the gelling properties and non-covalent interactions of fish gelatin were investigated. The gel strength and melting temperature of fish gelatin gradually increased, with increasing γ-PGA concentration, although there was no significant change when the γ-PGA concentration was greater than 0.04%. As the concentration of γ-PGA increased, the electrostatic interaction of fish gelatin increased and the hydrophobic interaction between gelatin molecules decreased. The fish gelatin system was comprised of γ-PGA concentrations of 0.04 and 0.06% showing a strong hydrogen bond. When the γ-PGA concentration increased from 0 to 0.04%, more phenolic hydroxyl groups in the tyrosine residue tended to form hydrogen bonds with the protein. However, an additional increase in γ-PGA concentration to 0.1% led to enhanced hydrogen bonding with water molecules. The results of this study showed that hydrogen bonds played an important role in improving the gelling properties of gelatin by γ-PGA.

Should intravenous gelatins have a role in contemporary peri-operative and critical care?

Should intravenous gelatins have a role in contemporary peri-operative and critical care?

Enhancing the biodegradability and surface protective performance of AZ31 Mg alloy using polypyrrole/gelatin composite coatings with anodized Mg surface

The intention of the current study is to improve the biodegradability and corrosion resistant performance of AZ31 Mg substrates by anodization and electrodeposition of polypyrrole/gelatin composite coatings. The effect of anodization time, and the concentration of gelatin on the biodegradability and corrosion protective performance of coated AZ31 Mg substrates were systematically evaluated using different characterization techniques. Surface topographical and morphological studies of anodized substrates indicated that the surface roughness, distribution of pores and pore size increased with increasing the anodization time. Water contact angle studies confirmed the improved surface wettability of AZ31 Mg substrates after anodization treatment. Surface characterization results of PPy/Ge composite coatings revealed the significant influence of gelatin addition on the surface morphology of PPy coatings. Structural characterization results confirmed that intermolecular chemical interaction exists between the polypyrrole moiety and gelatin molecules. It was also found that the anodized layer has enhanced the adhesion of PPy coatings from 3B to 5B. In vitro corrosion analysis indicated that the anodization layer efficiently improved the corrosion resistance behavior of coated AZ31 Mg substrates and this performance was increased with the addition of gelatin up to 1 wt% and then slightly reduced. Hydrogen evolution measurements corroborated that the amount of hydrogen evolved is significantly reduced in the presence of anodization layer and gelatin addition into PPy coating.

AuNPs composites of gelatin hydrogels crosslinked by ferrocene‐containing polymer as recyclable supported catalysts

ABSTRACTTo fabricate a recyclable supported catalyst based on gold nanoparticles (AuNPs) and gelatin hydrogel (HG) composites, a ferrocene (Fc)‐containing tetrablock copolymer [P(NCHO‐b‐NFc‐b‐NTEG‐b‐NCHO)] was used as both reducing and stabilizing agents for AuNPs and as a crosslinker for HG. First, the effects of Fc‐containing polymers, including homopolymer PNFc and copolymer P(NCHO‐b‐NFc‐b‐NTEG‐b‐NCHO), and different solvent systems on the morphology and aggregation of AuNPs were examined by using ultraviolet–visible spectroscopy, transmission electron microscopy, and dynamic light scattering. Second, two strategies (blending and soaking) were applied to prepare different AuNPs/HG composites (AuNPs‐HG), and their structure and properties were studied by using various techniques including scanning electron microscopy, X‐ray diffraction, and thermogravimetry. Finally, the catalytic performance and reusability of AuNPs‐HG‐1 (via blending) and AuNPs‐HG‐2 (via soaking) were evaluated utilizing the model catalytic reduction of 4‐nitrophenol to 4‐aminophenol by NaBH4. Results indicated that P(NCHO‐b‐NFc‐b‐NTEG‐b‐NCHO) dissolved in N,N‐dimethylformamide was the optimal reductant and stabilizer to prepare AuNPs. The in situ reduction of AuIII ions to Au0 particles was very essential for the fabrication of AuNPs‐HG in terms of hydrogel pore size, Au0 distribution and immobilization stability, and hydrogel thermal stability. Due to the stronger interactions among AuNPs, P(NCHO‐b‐NFc‐b‐NTEG‐b‐NCHO), and gelatin molecules in the blending strategy, AuNPs‐HG‐1 showed better mechanical stability and catalytic performance and more reusing cycles than AuNPs‐HG‐2. This work highlights the design and fabrication of robust recyclable supported AuNP catalyst by using eco‐friendly Fc‐containing HGs. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 137, 48653.

Physicochemical and Biological Properties of Gelatin Extracted from Marine Snail Rapana venosa.

In this study, we aimed to obtain gelatin from the marine snail Rapana venosa using acidic and enzymatic extraction methods and to characterize these natural products for cosmetic and pharmaceutical applications. Marine gelatins presented protein values and hydroxyproline content similar to those of commercial mammalian gelatin, but with higher melting temperatures. Their electrophoretic profile and Fourier transform infrared (FTIR) spectra revealed protein and absorption bands situated in the amide region, specific for gelatin molecule. Scanning electron microscopy (SEM) analysis showed significant differences in the structure of the lyophilized samples, depending on the type of gelatin. In vitro studies performed on human keratinocytes showed no cytotoxic effect of acid-extracted gelatin at all tested concentrations and moderate cytotoxicity of enzymatic extracted gelatin at concentrations higher than 0.5 mg/mL. Also, both marine gelatins favored keratinocyte cell adhesion. No irritant potential was recorded as the level of IL-1α and IL-6 proinflammatory cytokines released by HaCaT cells cultivated in the presence of marine gelatins was significantly reduced. Together, these data suggest that marine snails are an alternative source of gelatins with potential use in pharmaceutical and skincare products.

Pharmaceutical formulation analysis of a gelatin-based soft capsule film sheet containing phytic acid using near-infrared spectroscopy

In order to investigate the effect of phytic acid on the improvement of disintegration time (DT) of gelatin-based film sheets, gelatin film sheets and succinylated gelatin film sheets with various concentrations of phytic acid were dipped and stored in polyethylene glycol (PEG) 400 at 60 °C. The DT and near infrared (NIR) spectral changes were measured after storage. Gelatin showed a tendency to prolong DT caused by the formation of insoluble thin membranes due to the cross-linking of gelatin molecules, whereas succinylated gelatin did not show prolongation of DT. We also observed the preventive effect of phytic acid on the prolongation of DT of gelatin film sheets as the phytic acid concentration increased. From NIR measurements, it was considered that the –OH groups of phytic acid were coordinated with the hydrogen bonding position of gelatin molecules by replacing H2O or glycerin molecules. It was also thought that structural changes in the gelatin-water-glycerin complexes caused by phytic acid interfered with the access of peroxide or aldehyde generated from PEG 400 to the free ε–NH2 groups and prevented the cross-linking of gelatin molecules. On the other hand, because the free ε-NH2 groups of succinylated gelatin are protected by acid amidation, the cross-linking of succinylated gelatin was not observed.

Effect of squalene rich fraction from shark liver on mechanical, barrier and thermal properties of fish (Probarbus Jullieni) skin gelatin film

Golden carp skin gelatin films incorporated with squalene rich fraction from shark liver (SRF) at various levels (5, 10, 15, 20 and 25%, w/w) were characterized in comparison with palm oil (PO) incorporated film and control film (CON) (without oil addition). PO films exhibited lower tensile strength (TS) but higher elongation at break (EAB) as compared to that of CON film. SRF films added with 25% SRF showed higher EAB as well as TS, compared to both CON and PO films (p < 0.05). SRF films showed significantly lower water vapor permeability (WVP) and lower lightness (L*) value than CON and PO films (p < 0.05). Moreover, SRF films with negligible fishy odor had lower transparency and yellowness than CON and PO films. SEM images showed that CON and SRF films exhibited relatively smoother surface, compared to PO film. Additionally, SRF films had lower oil at the surface of the films than PO film. Moreover, DSC and FTIR spectra results revealed that incorporation of PO and SRF lowered interaction between gelatin molecules with coincidentally disordered structure. Besides, both SRF and PO films demonstrated lower degradation (Td), glass transition (Tg) and melting transition (Tm) temperatures than CON film. Thus, incorporation of SRF could render stronger films with higher TS and enhanced flexibility and also moisture barrier porperty of gelatin films.

Preparation and characterization of general-purpose gelatin-based co-loading flavonoids nano-core structure

Flavonoids (FLAs) possess anti-cancer, anti-viral, anti-bacterial, and anti-oxidant properties. In this study, gelatin nanoparticles (GNPs) with controllable surface potential and diameter was prepared through a modified two-step desolvation. Two well-known flavonoids, namely, low-molecular weight Genistein (GEN) and high-molecular weight Icariin (ICA), were adsorbed onto the surface of GNPs (FLA@GNPs). The characteristics of GNPs and the main parameters affecting flavonoid adsorption were studied to evaluate the adsorption capacity and structural stability of FLA@GNPs. Furthermore, co-adsorption of GEN and ICA was detected. The adsorption mechanism of GNPs with FLA was further discussed. Results showed that the low-molecular weight GEN could be effectively adsorbed by GNPs, and their entrapment efficiencies were over 90% under optimized conditions. The total drug loading of the co-adsorbed FLA@GNPs was significantly higher than that of the single drug loaded (GEN or ICA). GEN@GNPs could maintain its structural stability under acidic conditions (pH = 2) at room temperature (25 °C). This protective function enables both ICA and GEN to be bioactive at room temperature for at least 180 days. The characteristics of GNPs adsorption indicate that the hydrogen bonding theory of the combination of gelatin molecules with polyphenols cannot sufficiently explain the binding of GNPs with polyphenols. FLA@GNPs is a promising general-purpose gelatin-based co-loading preload structure with simplified operation and storage condition.

Infrared spectroscopic study of the coil-helix transition of highly concentrated gelatin formulations

The aim of this study was to investigate the applicability of ATR-FTIR spectroscopy as an analytical tool to monitor the gel formation of highly concentrated gelatin formulations. Spectral changes induced by the coil-helix transition have been studied and related to the elasticity parameter G′ obtained by oscillatory rheology in simultaneous measurements. A principal component analysis of the amide I band allowed the evaluation of triple helix formation kinetics. It was found that the key frequencies of the amide I band at 1657 and 1612 cm−1 represent the transition of the gelatin molecules from the random coil to the triple helical conformation in the emerging gel. A direct correlation between the conformation of the gelatin molecules and the gel elasticity was obtained for a commercially available pharmaceutical grade limed bone gelatin in concentrations between 20 and 40% w/w. The same was valid upon addition of small gelatin peptides or a helix inhibitor. No such correlation between triple helix content and G′ was found for limed bone gelatins of the same Bloom value but an asymmetric molecular weight distribution with extremely high fractions of high or low molecular weight components. This suggests that early gel elasticity is not solely linked to the triple helix nucleation. Hence, our results indicate that FTIR spectroscopy can be applied to gain a better understanding of the relationship between triple helix content and elastic gel properties of pharmaceutical gelatin capsule shell formulations.

Detection of Mast Cells Expressing c-Kit Using Antibody Covalently Bound to Gelatin Elongated from Surface of Immunosensor Based on Surface Plasmon Resonance.

An immunosensor based on surface plasmon resonance was applied to detect mast cells expressing c-Kit. Sufficient detection of the mast cells was achieved by covalent immobilization of gelatin firstly on the sensor surface and followed by covalent binding of the anti-c-Kit antibody to lysine residues in the gelatin molecules through bis(sulfosuccinimidyl)suberate (BS3) treatment. By using BS3, which is a homo-bifunctional reagent, the lysine residues of the anti-c-Kit antibody easily bound to the lysine residues of the gelatin in the physiological condition. The lower limit of detection was 104 cells/mL.

Study on facile designing, swelling properties and structural relationship of gelatin nanoparticles

In the present work glutaraldehyde crosslinked gelatin (Type-A and Type-B) nanoparticles were fabricated following a microemulsion crosslinking technique. The structural, morphological, and stability features of nanoparticles were investigated using the techniques like FTIR, TEM, XRD, DLS, and surface charge measurements. The spectral peaks appeared in the FTIR spectra of gelatin nanoparticles confirmed the crosslinking of gelatin molecules with glutaraldehyde. The SEM analysis of the nanoparticles suggested that the size of gelatin nanoparticles was nearly 300 nm whereas the TEM analysis revealed their size around 200 nm. The size of nanoparticles was found to increase with increasing amounts of gelatin while it showed a decrease when the concentration of crosslinker was increased. An increase in percent crystallinity was observed when gelatin was crosslinked with glutaraldehyde. The water uptake capacity of the gelatin nanoparticles was evaluated under varying experimental conditions like, pH, temperature, presence of simulated physiological fluids and varying composition of the gelatin nanoparticles. To study the cytotoxic behavior of gelatin nanoparticles in vitro cytotoxicity analysis were performed. The gelatin nanoparticles demonstrated good stability and biocompatibility which suggested that these particles can be used as drug carrier in fabricating a swelling controlled drug delivery system.

Effect of Carrageenan Addition to the Edible Characteristics of Tilapia Skin Gelatin Film (Oreochromis niloticus)

Gelatin of skin tilapia (Oreochromis niloticus) has the potential as an edible film but has weaknesses due to the hydrophilic so that the value of the water vapor transmission rate is high. The addition of carrageenan combined with palmitic acid is used to improve the characteristics of edible films modified bythe polymer network so that it can act as cross linking which is expected to reduce the rate of water vapor transmission rate edible film. indigo and get the best carrageenan concentration edible film seen from the value of the water vapor transmission rate. The ingredients used are tilapia skin gelatin, carrageenan and palmitic acid. The research method used was experimental laboratories with completely randomized design (CRD) experimental design. Parameters observed were thickness test, solubility, tensile strength, percent elongation and water vapor transmission rate. Data were analyzed using variance analysis (ANOVA). To find out the differences between treatments, the data was tested by HSD further tests. The results showed that the difference in carrageenan concentration significantly affected (P&lt;0,05) the thickness value, tensile strength, percent elongation, solubility and water vapor transmission rate. Addition of carrageenan 0.8% was the best result which has a tensile strength of 4.209 ± 0.241 MPa, elongation percent 16.332 ± 1.019%, solubility of 65.911 ± 2.930% and water vapor transmission rate of 7.792 ± 0.376 g / m2. Hour. Testing of tensile strength in 0,8% carrageenan film showed that the film matrix binds so that the film was not easily broken compared to the control. The low water vapor transmission rate in the 0.8% carrageenan addition edible film sample showed the formation of cross linking between gelatin and carrageenan protein molecules.