Gelatin Gel Research Articles

Effect of carbohydrates on protein hydrolysis in anaerobic digestion.

This study aimed to assess the effect of carbohydrates on protein hydrolysis and potential implications for the design of anaerobic reactors for treatment of protein-rich wastewaters. Batch experiments were carried out with dissolved starch (Sta) and gelatine (Gel) at different chemical oxygen demand (COD) ratios ranging from 0 to 5.5 under methanogenic conditions for methane production and up to 3.8 under non-methanogenic conditions for volatile fatty acids (VFA), both at 35 °C. The Sta/Gel did not have a direct effect on the gelatine hydrolysis rate constants under methanogenic (0.51 ± 0.05 L g VSS-1 day-1) and non-methanogenic conditions (0.48 ± 0.05 L g VSS-1 day-1). However, under non-methanogenic conditions, gelatine hydrolysis was inhibited by 64% when a spectrum of VFA was added at a VFA/Gel (COD) ratio of 5.9. This was not caused by the ionic strength exerted by VFA but by the VFA itself. These results imply that methanogenesis dictates the reactor design for methane production but hydrolysis does for VFA production from wastewater proteins.

Transglutaminase modified type A gelatin gel: The influence of intra-molecular and inter-molecular cross-linking on structure-properties

In this work, the structure–property differences and mechanisms of gelatin induced by transglutaminase (TGase) covalent cross-linking were investigated. The results showed that higher hardness was obtained with a cross-linking degree of 13.55%, attributing to an active intra-molecular cross-linking and a tight network structure under a certain amount of triple helix-like structure. The inter-molecular cross-linking played a positive role in the transition from random coil to left-handed single helix chains, while triple helix-like structure could not been formed owing to the steric hindrance and hydrogen bond reduction, showing the decrease of hardness and increase of viscosity. Additionally, the ε-(γ-Glu)-Lys isopeptide bond significantly increased the initial degradation temperature. Macromolecular polymers with a cross-linking degree of 37.48% allowed sol state of gelatin gel could be maintained even heating at 100 ℃ for 10 min. This study might provide an innovative reference for the regulation and application of gelatin gel structure-properties.

3D Printed gelatin film with Garcinia atroviridis extract.

Active packaging, such as edible film with antibacterial properties, can help extend the shelf life of food. The research aimed to develop a 3D printed gelatin edible film by using glycerol and Garcinia atroviridis extract (GAE). Mechanical properties of gelatin gel, physical, mechanical, and antimicrobial properties of edible film with glycerol and GAE were determined. Water solubility, total colour difference, and elongation of break of gelatin edible film increased as glycerol concentration increased (0-25% w/w), whereas tensile strength and Young's modulus value decreased from 26.5 to 4.64MPa and 3.04 to 0.13MPa, respectively. On the other hand, increasing GAE from 1 to 4% (w/w) increases elongation at break from 40.83 to 98.27%, while decreasing edible film tensile strength and gelatin gel hardness value from 8.94 to 6.21MPa and 1848.67 to 999.67g, respectively. Using 20% (w/w) glycerol and 4% (w/w) GAE, the best 3D printed film with low tensile strength (6.21MPa), high elongation at break (98.27%), and antibacterial activity against S. aureus with 7.23mm zone of inhibition was developed. It seems to have a great potentiality as an active packaging material for 3D printed gelatin edible film.

Socket preservation using gelatin hydrogel: A case report with radiographic analysis

The case report aims to evaluate radiographically a new bone formation in extraction sockets augmented with gelatin gel.16 was extracted atraumatically and then gelatin gel was grafted in the extraction socket. The margins were closed with periosteal releasing incision (closed-membrane technique). The implant was placed after 4 months of healing. Wound healing was unremarkable. radiographically, the bone reformation was observed in relation to 16. Immediate graft after extraction using gelatin gel is recommended for socket preservation.

Co(DTPA)]3− complex in gelatin gel as a highly sensitive shifting NMR/MRI temperature probe

Co(DTPA)]3− complex in gelatin gel as a highly sensitive shifting NMR/MRI temperature probe

Gelatin hydrogel reinforced by graphene oxide grafted chitosan for cartilage tissue engineering application

Various methods, such as cross-linking and incorporation of nanoparticles, enhance hydrogels’ physical and mechanical properties. Therefore, in the present research, gelatin (Gel) hydrogels cross-linked with an optimum amount of Genipin and then reinforced by the graphene oxide (GO)-grafted chitosan (CS). Gel is a derivative of collagen which can be found in cartilage tissue abundantly and shows relatively low antigenicity, GO has high tensile strength, GO raises the surface area for more interaction between cell and scaffold, CS is similar to glycosaminoglycan that can be found in the tissue ECM. For this purpose, at the first step, graphene oxide grafted chitosan (CS-g-GO) was synthesized successfully and identified by scanning electron microscope and Fourier Transform Infrared. Afterward, gelatin hydrogels with different percentages of the CS-g-GO were prepared and characterized. Results confirmed that structural and mechanical properties improved with increasing the GO concentration. Pore size increased from 244 to 287 µm with increasing CS-g-GO content; and swelling degree increased from 800% to 1200%, however, the compressive stress rose from 40 to 65 kPa, more like healthy articular cartilage. The degradation rate also declined from 70% to 50% during 28 days. Cell viability remains more than 90% in 5 days, which indicates the biocompatibility of the samples. To conclude, hydrogels synthesized in this research are promising for cartilage tissue engineering.

A Multicomponent Butyrylcholinesterase Preparation for Enzyme Inhibition-Based Assay of Organophosphorus Pesticides

A new method of producing butyrylcholinesterase (BChE) preparations, stable in storage and use, has been proposed. The BChE preparation is the enzyme co-immobilized with 0.2 M 5-5′-dithiobis (2-nitrobenzoic acid) in starch or gelatin gel. All experimental preparations retain enzyme activity for at least 300 d. The preparations based on gelatin gel show higher activity but lower sensitivity to the toxicants tested in this study compared to the starch gel-based preparations. A method has been proposed for integrated detection of anti-cholinesterase substances in aqueous solutions using the experimental preparation with immobilized BChE. After the additional incubation of the preparation with the immobilized enzyme in the solution of the analyte, the detection limits of malathion and pirimiphos-methyl determined using the IC20 values were below their maximum allowable concentrations—0.005 µM and 0.03 µM, respectively.

Electrospinning of Poly(Caprolactone)/Gelatin/Clindamycin Nanocomposites as an Antibacterial Wound Dressing

These days, nanofibers are used in the medical sector, such as drug delivery and wound dressing structures, because of their excellent characteristics, high permeability, and important surface area. Natural and synthetic polymers may be electrospun in the form of a blend. Besides, the antibiotics such as linezolid, enrofloxacin, and vancomycin are used in wound dressing due to their antibacterial properties. In this research, the blend nanofibrous structures made of PCL and gelatin (Gel) with a 25:75 ratio were produced for wound dressing applications. Clindamycin HCL as a drug was added to Gel and PCL polymeric solutions. Surface morphology, functional groups, and hydrophilicity of nanofibers were examined using SEM, FT-IR spectroscopy, and contact angle measurement, respectively. In addition, the antibacterial properties of nanofibers were evaluated quantitatively. The drug release mechanism of samples was investigated which the best-fitted model was recognized Korsmeyer-Peppas model. SEM images of scaffolds demonstrated uniform and bead-free morphology that, with incorporating the 6% of the drug, the diameters of mats were decreased from 398 nm to 303 nm. Moreover, the samples showed proper hydrophilicity and antibacterial properties against a gram-positive (89%) and a gram-negative (98%) bacterium. Finally, the nanofibers are capable of releasing the clindamycin gradually for 6 days.

Gelatin Nanoparticles for Targeted Dual Drug Release out of Alginate-di-Aldehyde-Gelatin Gels.

The aim of the present work was to develop a dual staged drug release of an antibiotic (clindamycin) and a growth factor: bone morphogenetic protein-2 (BMP-2) from a biodegradable system consisting of hydrogel and gelatin nanoparticles (GNP). Two-step de-solvation allowed us to prepare GNPs (~100 nm) as drug carriers. Fluorescein isothiocyanate (FITC)-conjugated protein A was used as a model substance for BMP-2. A 28-day release experiment was performed to determine the release kinetics from GNP for both FITC-protein A and BMP-2, and for clindamycin (CLI) from the hydrogel. The size, structure, and overall morphology of GNP samples (empty, loaded with FITC-protein A and BMP-2) were examined using an environmental scanning electron microscope (ESEM). Cell culture assays (Live/dead; cell proliferation; cytotoxicity) were performed with MG-63 cells and BMP-2-loaded GNPs. Drug release experiments using clindamycin-loaded alginate-di-aldehyde (ADA) gelatin gels containing the drug-loaded GNPs were performed for 28 days. The resulting GNPs showed an empty size of 117 ± 29 nm, 176 ± 15 nm and 216 ± 36 nm when containing 2% FITC-protein A and 1% BMP-2, respectively. No negative effects of BMP-2-loaded GNPs on MG-63 cells were observed in live/dead staining. In the proliferation assay, an increase in cell proliferation was observed for both GNPs (GNP + BMP-2 and controls). The cytotoxicity assay continuously showed very low cytotoxicity for GNPs (empty; loaded). Clindamycin release showed a concentration of 25-fold higher than the minimum inhibitory concentration (MIC) against Staphylococcus aureus throughout the 28 day period. BMP-2 showed a reduced burst release and a steady release (~2 µg/mL) over a 28 day period.

Maturation of induced pluripotent stem cell-derived cardiomyocytes and its therapeutic effect on myocardial infarction in mouse.

Induced pluripotent stem cell-derived cardiomyocytes (iPSC-CMs) have an irreplaceable role in the treatment of myocardial infarction (MI), which can be injected into the transplanted area with new cardiomyocytes (Cardiomyocytes, CMs), and improve myocardial function. However, the immaturity of the structure and function of iPSC-CMs is the main bottleneck at present. Since collagen participates in the formation of extracellular matrix (ECM), we synthesized nano colloidal gelatin (Gel) with collagen as the main component, and confirmed that the biomaterial has good biocompatibility and is suitable for cellular in vitro growth. Subsequently, we combined the PI3K/AKT/mTOR pathway inhibitor BEZ-235 with Gel and found that the two combined increased the sarcomere length and action potential amplitude (APA) of iPSC-CMs, and improved the Ca2+ processing ability, the maturation of mitochondrial morphological structure and metabolic function. Not only that, Gel can also prolong the retention rate of iPSC-CMs in the myocardium and increase the expression of Cx43 and angiogenesis in the transplanted area of mature iPSC-CMs, which also provides a reliable basis for the subsequent treatment of mature iPSC-CMs.

반응표면분석을 이용한 카파 카라기난과 염화칼슘 첨가 고령친화형 젤라틴 젤의 최적 배합비율 확립

The objective of this study was to determine the optimal mixing ratios of pork skin gelatin, κ-carrageenan, and calcium chloride for manufacturing senior-friendly gelatin gels with hardness for tongue or gum intake, as well as fulfilling protein, dietary fiber, and calcium contents of the Korean industry standard (KS) for senior-friendly foods. The optimal mixing ratio of the ingredients was determined within 6.60~33.3% (w/v) pork skin gelatin, 2.50~6.25% (w/v) κ-carrageenan, and 0.235~2.351% (w/v) calcium chloride using response surface methodology. The mixing ratios for the senior-friendly gelatin having the hardness of 2 to 5 N/cm2 were predicted as 6.605~11.331% (w/v) pork skin gelatin, 2.74~6.25% (w/v) κ-carrageenan, and 0.235% (w/v) calcium chloride. The amounts of nutrients (proximate composition, calcium, and dietary fiber contents) in the senior-friendly gelatin gels were significantly affected by changing the mixing ratio of the three ingredients. In conclusion, thereby mixing 6.605~11.331% (w/v) pork skin gelatin, 2.74~6.25% (w/v) κ-carrageenan, and 0.235% (w/v) calcium chloride, it could be confirmed to control the hardness corresponding to 2nd to 3rd hardness grades of senior-friendly gelatin gels, with fulfilling the nutrients standards for 6 g of protein, 80 mg of calcium, and 2.5 g of dietary fiber per 100 g of product.

Protein and polysaccharide-based asymmetric mat with tuned bilayer configuration for enhanced wound healing efficiency

In this research we focused on the fabrication of an asymmetric bilayer membrane with core-shell/simple layer configuration providing the functions of needed hierarchically hydrophilicity and porosity, anti-infectious, tissue adhesion as well as degradation and integration with tissue, cells proliferation, and enhanced promotion of tissue regeneration. The bilayer membrane composed of collagen (Col), chitosan (CS), aloe vera (AV) and gelatin (Gel), not only simulates the features of the epidermis and dermis layer of a natural skin but also benefits from the materials necessary for the regeneration of injured skin tissue during the healing process. The results of full-thickness skin wound evaluation revealed that the fabricated asymmetric membrane could facilitate wound healing within 10 days mainly through enhancing cellular activities, enhancing collagen deposition, and promoting proliferation. Results of histopathological analysis and immunohistochemistry after 10 days of treatment, demonstrated more re-epithelialization and collagen density for the treated groups compared to the control group.

Gelatin-lecithin-F127 gel mediated self-assembly of curcumin vesicles for enhanced wound healing

Curcumin, a principal component of Curcuma longa, has a long history of being used topically for wound healing. However, poor aqueous solubility of curcumin leads to poor topical absorption. Recently, gelatin based gel has been reported to overcome this issue. However, the release of curcumin from gelatin gel in the bioavailable or easily absorbable form is still a challenge. The present study reports the development of a composite gel prepared from gelatin, F127 and lecithin using temperature dependant gelation and loading of curcumin within it. Notably, the composite gel facilitated the release of curcumin entrapped within vesicles of ~400 nm size. Further, the composite gel exhibited increase in the storage modulus or gel strength, stability, pore size and hydrophobicity as compared to only gelatin gel. Finally, wound healing assay in murine model indicated that curcumin delivered through composite gel showed a significantly faster healing as compared to that delivered through organic solvent. This was also validated by histopathological and biochemical analysis showing better epithelization and collagen synthesis in the group dressed with curcumin containing composite gel. In conclusion, composite gel facilitated the release of bioavailable or easily absorbable curcumin which in turn enhanced the wound healing.

Effect of Sugars on Gelation Kinetics of Gelatin Gels

We investigate the rheological behavior of aqueous solutions containing animal gelatin, sugars and polyols. The aim is to study how the gelation kinetics, transition temperatures and gel strengths of an aqueous gelatin solution can be affected by the progressive addition of co-solutes. Aqueous solutions with a fixed mass percentage of gelatin of 6.8 wt% were prepared at various concentrations of sugars and polyols. Through Dynamic Temperature Ramp tests, performed at various ramp rates, and Dynamic Time Sweep and Dynamic Frequency Sweep tests, carried out at different temperatures, it was possible both to evaluate the transition temperatures and to monitor the gelation kinetics of the samples. It was found that the contribution of co-solutes positively affects both the gelation process and the thermal stability of the aqueous gelatin solution by reducing the gelation time and improving the mechanical properties of the gel in terms of network elasticity.

Development of Cancer‐on‐a‐chip Technology for the Study of Tumor Microenvironment and Metabolism

Cancer metabolism has become an area of intense interest. In the 1920s, Otto Warburg showed that cancer cells metabolize glucose to produce lactate and ATP in the presence of oxygen, i.e. aerobic glycolysis, also known as the Warburg Effect. It is now appreciated that cancer cells display a complex metabolic phenotype. Metabolic reprogramming by oncogenes and tumor suppressor genes has been linked to the altered metabolic function of cancer cells. However, the tumor microenvironment (TME), which has different nutrient gradients for glucose, oxygen, and amino acids, has a dramatic effect on cancer cell growth and proliferation. In vivo studies have demonstrated a heterogeneous metabolic phenotype that is difficult to characterize. In addition, the exchange of nutrients and metabolites between the TME, vasculature, and tumor cells has been difficult to fully recapitulate. As a tumor grows, nutrients diffuse from the blood vessels to the cancer cells, in a process partially described by A. Krogh in 1919 through a reaction‐diffusion differential equation. Krogh’s work showed that for typical tissues the oxygen decay radius is around 150μm and we find approximately the same ‘Krogh radius’ for high glucose consumption cancer cells (e.g. MDA‐MB‐231). Thus, around 150μm from a blood vessel exists an oxygen deprived environment that imposes tremendous competitive stresses on the cancer cells for survival. There is rising evidence that this selection pressure favors the transformation to metastasis and causes invasive tumor cell lines to exhibit high glycolytic rates and overall metabolic reprogramming. However, most studies focused on defining the metabolic function of tumor cells have been conducted in vitro, under conditions that do not represent the physiological conditions accurately.Here, we present a cancer‐on‐a‐chip technology that produces a well‐defined 3D TME that can be exposed to precise nutrient stresses such as varying oxygen or other nutrient gradients. In addition, we can determine the metabolic phenotype of cancer cells with varying oncogenic changes and degrees of aggressiveness. Our technology should be able to address the question of the role of the TME on metabolic reprogramming and in particular glycolysis. Our design is based on growing tumor microenvironments inside 360µm ID capillary tubing that can be accessed by 360µm PEEK tubing. To allow/control perfusion through the microenvironment we embed a 70µm nylon fiber into a photocross‐linkable gelatin gel in which the cells are dispersed (MDA‐MB‐231/GFP). After exposing the gel to UV‐light for a few seconds, the nylon fiber is pulled, leaving a perfusable microchannel. Using this technique, we have successfully perfused cell‐laden hydrogels over weeks while observing cell‐growth in a fluorescence microscope.

Gel-sol and colorimetric dual-modal sensor for highly selective and sensitive detection of iodide ions based on gelatin fabricated AuNPs

Excessive intake or lack of iodide ions (I-) will have serious impact on human growth and health. Therefore, the highly selective and sensitive detection of I- is particularly urgent. Herein, a dual-modal sensor based on colorimetric and gel-sol signal responses has been developed for the visual detection of I-. Visual sensing based on I- triggered dual-signal simultaneous response can reduce the interference of false positive signals and improve detection accuracy. This dual-modal sensor (Gel-AuNPs) is constructed by the in situ reduction of chloroauric acid using gelatin (Gel) with unique topological structure and reduction properties to prepare gold nanoparticles (AuNPs). The presence of I- can induce a noticeable color change from red to yellow (attributed to the occurrence of redox reaction), and the selective visual detection of I- was realized in a wide concentration range with a linear fitting coefficient of 0.9983 and a limit of detection (LOD) of 30.1 μM. Simultaneously, based on the change in viscosity in the gel-sol phase transformation process (attributed to the salting-in effect of I-), the quantitative relationship of I- detection (R2 = 0.9937) was then established. Furthermore, the Gel-AuNPs hydrogel exhibited high sensitivity for detecting I- in actual water samples such as seawater and tap water. More importantly, the in situ synthesized Gel-AuNPs showed good solid-state stability and strong salt tolerance, implying the potential scope of their practical application in different harsh conditions. As such, this visual sensing system with dual signal responses will have prospective applications in detection and analysis in due course.

How a Gel Can Protect an Egg: A Flexible Hydrogel with Embedded Starch Particles Shields Fragile Objects Against Impact.

Hydrogels are networks of polymer chains that are swollen in water. In recent years, several routes have been devised to make hydrogels that are flexible and bendable. This work investigates whether such flexible gels can be wrapped around brittle or fragile objects (such as an egg or a fruit) and protect the objects against impact. We study gels made by either physical cross-linking (e.g., gelatin) or chemical cross-linking (e.g., acrylamide) and the same gels with various particulate additives. None of the bare gels are protective, and nanoparticles like iron oxide or silica do not help. However, the addition of starch granules to the above gels greatly enhances their protective abilities. When a load strikes a gelatin gel containing 20% starch, the peak impact force is reduced by 25% when compared to a bare gel without the starch. Correspondingly, the coefficient of restitution (COR) is also lowered by the presence of starch (i.e., a ball bounces less on a starch-bearing gel). We correlate the impact-absorbing effects of starch granules to their ability to shear-thicken water. When starch granules are gelatinized by heat, they no longer give rise to shear-thickening, and in turn, their protective ability in a gel is also eliminated. Our research can guide the rational design of protective coatings or armor for fragile objects, which could be applied in the sports, defense, and consumer sectors.

Orsellinic acid-loaded chitosan nanoparticles in gelatin/nanohydroxyapatite scaffolds for bone formation in vitro

AimOrsellinic acid (2,4-Dimethoxy-6-methylbenzoic acid) (OA) is a hydrophobic polyphenolic compound with therapeutic potential, but its impact on actuating osteogenesis remains unknown. The bioavailability of OA is hampered by its hydrophobic nature. This study aimed to fabricate nano-drug delivery system-based scaffolds for OA and test its potential for osteogenesis in vitro. Materials and methodsOA was loaded into chitosan nanoparticles (nCS + OA) using the ionic gelation technique at different concentrations. nCS + OA were incorporated onto the scaffolds containing gelatin (Gel) and nanohydroxyapatite (nHAp) by the lyophilization method. Biocomposite scaffolds were examined for their physicochemical and material characteristic properties. The effect of OA in the scaffolds for osteoblast differentiation was determined by alizarin red and von Kossa staining at the cellular level and by reverse transcriptase-qPCR and western blot analysis at the molecular level. Key findingsThe scaffolds showed excellent physiochemical and material characteristics and remained cyto-friendly to mouse mesenchymal stem cells (mMSCs, C3H10T1/2). The release of OA from Gel/nHAp/nCS scaffolds enhanced the differentiation of mMSCs towards osteoblasts, as observed through cellular and molecular studies. Moreover, the osteogenic potential of OA was mediated by the activation of FAK and ERK signaling pathways through integrins. SignificanceThe inclusion of OA into Gel/nHAp/nCS biocomposite scaffolds at 80 μM concentration promoted osteoblast differentiation via cell adhesion mediated signaling, compared with that shown by Gel/nHAp/nCS alone. Overall, this study identified the potential therapeutic OA containing Gel/nHAp/nCS scaffolds, accelerating its potential for clinical application towards bone regeneration.

Magnetic Nanofibrous Scaffolds Accelerate the Regeneration of Muscle Tissue in Combination with Extra Magnetic Fields.

The reversal of loss of the critical size of skeletal muscle is urgently required using biomaterial scaffolds to guide tissue regeneration. In this work, coaxial electrospun magnetic nanofibrous scaffolds were fabricated, with gelatin (Gel) as the shell of the fiber and polyurethane (PU) as the core. Iron oxide nanoparticles (Mag) of 10 nm diameter were added to the shell and core layer. Myoblast cells (C2C12) were cultured on the magnetic scaffolds and exposed to the applied magnetic fields. A mouse model of skeletal muscle injury was used to evaluate the repair guided by the scaffolds under the magnetic fields. It was shown that VEGF secretion and MyoG expression for the myoblast cells grown on the magnetic scaffolds under the magnetic fields were significantly increased, while, the gene expression of Myh4 was up-regulated. Results from an in vivo study indicated that the process of skeletal muscle regeneration in the mouse muscle injury model was accelerated by using the magnetic actuated strategy, which was verified by histochemical analysis, immunofluorescence staining of CD31, electrophysiological measurement and ultrasound imaging. In conclusion, the integration of a magnetic scaffold combined with the extra magnetic fields enhanced myoblast differentiation and VEGF secretion and accelerated the defect repair of skeletal muscle in situ.

High efficient crosslinking of gelatin and preparation of its excellent flexible composite film using deep eutectic solvent

To overcome the gelation of gelatin at low temperatures, solve the brittleness of gelatin-based films and improve the reaction efficiency between the components, a facile design strategy is proposed for preparing gelatin/polyvinyl alcohol composite films (Gel-PVAs) with excellent flexibility. During the preparation process, sodium acetate trihydrate/urea deep eutectic solvent (SAT/U-DES) was introduced to dissolve the gelatin, which not only exhibited the higher crosslinking efficiency but also induced the plasticizing effect to the composite film. When the DES mass fraction was 60%, the solubility of the gelatin was up to 25%, and gelation did not occur at room temperature. In addition, the elongation at break of the Gel-PVA60 film reached up to 654%, which was a 631% increase when compared with that of the Gel-PVA0 film. These remarkable properties were due to the formation of new H-bonds with the groups in gelatin molecules induced by SAT/U-DES, which limited the reformation of the gelatin structures after cooling and improved the flexibility and ductility of the film. Moreover, the destruction of interchain interactions between the gelatin molecules allowed more carboxyl groups to react with PVA in the crosslinking modification system, which resulted in an improvement of the reaction efficiency without external catalysts.