Liquid Gelatin Research Articles

Phase behaviour and structure formation of alginate-gelatin composite gels

Alginate-gelatin composite gels are widely used in food and biomedical applications. These composite gels are particularly interesting for their ability to establish complex functionalities, such as in bioinks for 3D bioprinting. In order to understand and optimise their techno-functionalities, it is crucial to study the structure formation, which is influenced by molecular interactions and phase behaviour.Therefore, the aim of this study was to characterise the effect of mixing ratio and temperature (21 and 40 °C) on the phase behaviour and structure formation of alginate-gelatin composite gels using internal alginate gelation with Ca-EDTA and D-glucono-δ-lactone. We compared pure alginate gels and composite gels using oscillatory rheology, pH measurements during gelation and microstructural analysis through confocal laser scanning microscopy.The temperature-dependent state of the gelatin - liquid or gelled - strongly influenced the gelation velocity of alginate. At 40 °C, liquid gelatin delayed the gelation process by buffering the pH decrease. This effect was most pronounced in the presence of excess gelatin, which had a strong antagonistic effect on gel strength. At 21 °C, gelled gelatin resulted in a faster alginate gelation and the formation of phase-separated networks at all mixing ratios. This was also accompanied by antagonistic effects on the gel strength. The phase-separated networks showed different microstructures with high-contrast regions depending on the mixing ratio, which correlated with variations in the turbidity of the gels. These insights into the structure-function relationship of alginate-gelatin composite gels may enable the customisation of specific network types for the use in 3D bioprinting.

Comparison of the effects of hydroxyethyl starch and succinylated gelatin infusion on the perfusion index in elective caesarean sections under spinal anaesthesia

Aim: This study is to compare the alterations of three different replacement fluids on Perfusion Index, Pleth Variability Index (PI, PVI) and hemodynamic data in cases planned to experience caesarean surgery under spinal anaesthesia. Material and Method: 94 ASAII class patients aged 18–40 that were planned to experience caesarean surgery were included in the study. The patients were divided into three groups according to the fluid replacement to be applied. Patients in Group H received 10 ml/kg of hydroxyethyl starch (HES) up to a maximum of 500 ml over 20 minutes. Patients in Group G got 10 ml/kg of modified liquid gelatin(GEL) up to a maximum of 500 ml over 20 minutes. Patients in Group I got 20 ml/kg of isotonic sodium chloride (0.9% NaCl) over 20 minutes. Routine monitoring and perfusion index, pleth variability index were recorded baseline and at the first, third and tenth min after spinal anaesthesia for all participants Results: A significant increase in the PI value over time was observed in Groups G and I (p=0.001*). According to the PVI results, the amount of decrease in Group G was statistically less than in the other two groups (p=0.015*). Conclusion: In conclusion, 0.9% NaCl and gelatine were more effective on PI in caesarean section under spinal anesthesia. Isotonic has a positive effect on both PI and PVI. We detected that PI increased compared to baseline values, and believe that this increase may a positive effect on tissue circulation in the patient.

Coaxial structured drug loaded dressing combined with induced stem cell differentiation for enhanced wound healing

Controllable drug-loaded dressings combined with induced stem cell differentiation have received considerable interest. In this study, a directional core-shell drug-loaded magnetocaloric response PCL/Gelatin-Antibiotics/Fe3O4 multifunctional dressing was developed. Due to the magnetothermal heating effect of magnetic nanoparticles and the contraction of elastic electrospun fibers, the fibers release antibiotics as needed to prevent drug-resistant infection. IV collagenase catalyzes the degradation of gelatin by achieving an optimum reaction temperature, the purpose of which is also to reduce the viscosity of liquid gelatin and promote the release of drugs. With the sacrifice of gelatin, the directional structure of scaffold and the internal steric hindrance promoted stem cell differentiation and wound healing. The expression of Vimentin, VEGF, bFGF, TGF-β, and THY1 was confirmed by fluorescence immunostaining and RT-PCR. Western blot was used to detect expression of Vimentin, collagen, CD34, and CD31 in the (5/5, v/v) PCL/gelatin scaffold incubated with mouse wound. Therefore, the functional fibers can significantly accelerate the healing process.

Methods for obtaining the enriched fraction of ram seminal vesicle proteins (RSVP14)

The objective of the present study was to develop a methodology to obtain the enriched fraction of ram seminal vesicle protein 14 (RSVP14). The study was developed using Morada Nova rams, from which semen samples were collected weekly. Seminal plasma proteins were precipitated with cold ethanol, and then 6.15 mg/mL of total proteins were subjected to liquid gelatin affinity chromatography using a Gelatin-Sepharose matrix coupled to an automated chromatographic system. Proteins were eluted into four fractions (A, B, C, [...]

Gelatin embedding and LED autofluorescence reduction for rodent spinal cord histology

We present two innovations in histological technique for rodent spinal cord: gelatin embedding and LED photobleaching. Gelatin embedding uses liquid gelatin solution to permeate delicate biological structures then solidify to provide mechanical support throughout dissection, vibratome sectioning, and staining. LED photobleaching uses high-intensity visible light during blocking and primary incubations to reduce autofluorescence in tissue sections before fluorescent secondaries are added. We found gelatin embedding improved mechanical stability without interfering with immunohistochemical staining. Gelatin embedding also preserved some spinal roots and provided an opportunity for dye-less and cut-less tracking of left/right orientation during free-floating staining, which is valuable for tissue samples that have no spare areas that can be marked. LED photobleaching greatly reduced autofluorescence and added essentially no extra time or labor to the process. Descriptions of the techniques and characterization data are provided.

Sustainable Preparation of Microcapsules with Desirable Stability and Bioactivity Using Phosphonium Ionic Liquid as a Functional Additive

A microcapsule is an ideal choice to realize effective utilization of a pesticide and reduce environmental pollution. A novel preparation method of a microcapsule was developed by complex coacervation of phosphonium ionic liquid (PIL) with gelatin. PIL was newly synthesized and used to dissolve and disperse avermectin (Ave) to form stabilized core–shell structure microcapsules by cross-linking with gelatin in a solution. The results demonstrated that avermectin–phosphonium ionic liquid–gelatin (Ave–PIL–Gel) microcapsules had a high Ave entrapment efficiency (approximately 98% w/w), and could effectively enhance the stability of Ave by reducing its degradation in the environment. The Ave release of synthesized Ave–PIL–Gel microcapsules was governed predominantly by non-Fickian diffusion, and the release rates showed positive correlation with the temperature and the base conditions. Compared with the Ave technical solution, the Ave–PIL–Gel microcapsules had better nematicidal activities against plant-parasitic nematodes and showed great potential for sustainable crop protection. The present study provides an improved controlled release formulation comprising a pesticide, which is sensitive to light and easily degradable in soil encapsulated in negatively charged protein, and also provides an environmentally friendly method for preparing the improved pesticide formulation so that the pesticide release rate and release period can be adjustable.

Effect Maltodextrin on Hedonic Attributes of Tray-Dried Fish Gelatin Powder from Bone of Pangasius sp.

Abstract—This research aims to drying liquid gelatin from bone of pangasius sp. through maltodexrtrin addition by using tray dehydrator. The stages of this study were including fish bone gelatin extraction and drying of liquid gelatin at 55 oC for 6 hours coupled with addition of maltodextrin (0%, 5%, 8%, 11%, and 14%). The analysis covering gelatin yield and organoleptic parameter i.e hedonic test toward color, aroma, texture, and overall preference. Then, proximate analysis was done also on the selected dried fish bone gelatin. The results shown that maltodextrin addition has significant effect to the hedonic attributes of resulting fish bone gelatin powder by tray drying process. The panelists preference toward fish bone gelatin powder with maltodextrin is like slightly whether to color, aroma, texture, and overall appearance. The yield of dried fish bone gelatin using tray dehydrator is about 16%. The moisture, ash, protein and fat compositions of dried fish bone gelatin in this study were 11.45%, 0.96%, 36.15%, and 0.045% respectively. 
 Keywords—drying; fish gelatin; halal gelatin; maltodextrin; organoleptic

Dike Channelization and Solidification: Time Scale Controls on the Geometry and Placement of Magma Migration Pathways

AbstractWe investigate the conditions under which magma prefers to migrate through the crust via a dike or a conduit geometry. We performed a series of analogue experiments, repeatedly injecting warm, liquid gelatin, into a cold, solid gelatin medium and allowing the structure to evolve with time. We varied the liquid flux and the time interval between discrete injections of gelatin. The time interval controls the geometry of the migration, in that long intervals allow the intrusions to solidify, favoring the propagation of new dikes. Short time intervals allow the magma to channelize into a conduit. These times are characterized by the Fourier number (Fo), a ratio of time and thermal diffusion to dike thickness, so that long times scales have Fo > 102 and short time scales have Fo < 100. Between these time scales, a transitional behavior exists, in which new dikes nest inside of previous dikes. The flux controls the distance a dike can propagate before solidifying, in that high fluxes favor continual propagation, whereas low fluxes favor dike arrest due to solidification. For vertically propagating dikes, this indicates whether or not a dike can erupt. A transitional behavior exist, in which dikes may erupt at the surface in an unstable, on‐and‐off fashion. We supplemented the experimental findings with a 2‐D numerical model of thermal conduction to characterize the temperature gradient in the crust as a function of intrusion recurrence frequency. For very infrequent intrusions (Fo > 104 to 105) all thermal energy is lost, while more frequent intrusions allow heat to build up nearby.

Modeling counterion partition in composite gels of BSA with gelatin following high pressure treatment

We examine the morphology of hydrogels made of bovine serum albumin and gelatin following high pressure processing at 300 MPa for 15 min at 10 and 80 °C. Emphasis is on the distribution of added calcium counterions between the polymeric phases seen in changes in the structural properties of the composite gel. Protocol includes thermal and HPP treatments, dynamic oscillation rheology, ESEM, and modeling from the “synthetic polymer approach” to rationalize results. Pressurization at 10 °C produced continuous gelatin networks with dispersed BSA inclusions whereas pressurization at 80 °C yielded an inverse dispersion of BSA as the continuous phase supporting liquid gelatin inclusions. Lewis and Nielsen equations were adapted to predict the counterion distribution between the polymeric phases that profoundly affected the structural properties of the pressurized gels. The concept of counterion partition (pc) is introduced to the literature to follow the phase behavior of the composites in the presence of added calcium counterions.

Optimization of a Gelatin–Potassium Phosphate Aqueous Two-Phase System for the Preparation of Hydrogel Microspheres

An aqueous two-phase system provides a simple route toward the preparation of gelatin emulsions. Here, we present a simple method to generate water-in-water (w/w) emulsions from an aqueous two-phase system: gelatin and potassium phosphate (K2HPO4) salt. Liquid gelatin forms as the dispersed phase of the two-phase emulsion system, and gelatin microspheres can be retrieved after a visible light-induced crosslinking reaction. We investigated the effect of the continuous phase volume ratio on the formation of the phase-separation and emulsification process. We also studied the influence of the polymerization method on the size and morphology of gelatin hydrogel particles. The results demonstrated that K2HPO4 is an appropriate phase-forming salt, where biodegradable gelatin particles obtained through this w/w emulsion system have potential for biomedical applications. In addition, sustained release of a model molecule, methylene blue, was observed for up to 5 days from gelatin particles. This system is advantageous because if provides an inexpensive emulsion platform that avoids the use of organic solvents or auxiliary polymers to form a continuous phase.

Modeling counterion partition in composite gels of BSA with gelatin following thermal treatment

This study deals with the distribution of added calcium ions and their effect on the phase behaviour of hydrogels made of bovine serum albumin and gelatin. Structural properties of single and mixed systems were identified using small-deformation dynamic oscillation in shear, microdifferential scanning calorimetry and scanning electron microscopy. The experimental procedure was designed to encourage formation of micro phase-separated materials, where i) a continuous gelatin matrix supported liquid BSA inclusions, ii) an inverted dispersion of gelled BSA was interspersed by liquid gelatin inclusions and iii) a rigid BSA phase supported softer filler particles of gelatin. The Lewis-Nielsen equations and a series of models developed by Takayanagi were adapted for predicting the phase behaviour of BSA/gelatin mixtures in the presence of added calcium chloride. As far as we are aware, this is the first attempt to model the partition of added counterions between polymeric phases in binary hydrogels based on classic blending law analysis.

Determining the Ibuprofen Concentration in Liquid-Filled Gelatin Capsules To Practice Collecting and Interpreting Experimental Data, and Evaluating the Methods and Accuracy of Quality Testing

A laboratory experiment to determine the concentration of the anti-inflammatory drug ibuprofen in liquid gelatin capsule dosage forms, suitable for undergraduate chemistry or pharmacy students, is described. Either individually, or in small teams, the students digest two 200 mg capsules in a KOH solution. While the capsules are digesting the students prepare a range of ibuprofen standards and determine their UV absorbance at 264 nm. Next, the students use the data to both determine the drug’s extinction coefficient using the Beer–Lambert equation and to plot a calibration graph. Using both the extinction coefficient and the calibration graph the students are then required to determine the amount of ibuprofen in each of their capsules. In undertaking the laboratory class, the students are required to complete a results data sheet, determine whether the capsules are within specification, and answer questions that prompt them to evaluate the different calculation methods and the accuracy of the tests. In the...

Modeling water partition in composite gels of BSA with gelatin following thermal treatment

A thorough experimental procedure of controlled cooling, isothermal at low temperature, heating, isothermal at high temperature and a second cooling run were carried out to record and rationalise the structural properties of BSA-gelatin mixtures over a wide range of temperature and polymer concentration. Research methodology included small-deformation dynamic oscillation in-shear, micro-differential scanning calorimetry, scanning electron microscopy and semi-theoretical modeling based on ideas of relating the elastic modulus of amorphous synthetic polymers to the topology of their binary blends. Cooling of solutions from ambient temperature produces gelatin continuous matrices supporting the BSA droplets, and modeling of the mechanical readings using an appropriate Lewis-Nielsen equation argues that the former is a highly hydrophilic molecule. Heating melts the gelatin network and leads to the formation of a continuous BSA structure, with dispersed inclusions of liquid gelatin, but produces a solvent partition factor in favour of the globular-protein gel. Subsequent cooling forms solid-like particles of gelatin within the interstices of the continuous BSA network. Modeling of steric exclusion phenomena in this filler composite using the isostrain blending law further supports the concept of increasing proportions of water being trapped within the continuous matrix of a biphasic gel.

Intraoperative Adductor Canal Block for Augmentation of Periarticular Injection in Total Knee Arthroplasty: A Cadaveric Study

BackgroundFunction is often sacrificed for pain control after total knee arthroplasty. Motor-sparing blocks, including adductor canal block (ACB) and periarticular injection (PAI), have gained interest to address this compromise. Our study evaluates the anatomic feasibility, accuracy, and safety of intraoperative ACB as an adjunct to PAI by analyzing 3 different injection orientations and needle configurations. MethodsEleven cadaveric knees underwent a standard medial parapatellar arthrotomy. Blunt dissection through the suprapatellar recess was performed. Using a 10-mL syringe, various colors of dyed liquid gelatin were injected toward the proximal and distal adductor canal (AC) using 3 needle configurations. Medial dissection of the knee for each specimen was performed. The position of each needle and location of injected dye was identified and described relative to the AC. ResultsAccuracy of each injection orientation and/or needle configuration was different: 86% for a blunt needle in the distal AC, 57% for blunt needle in the proximal AC, and 14% for a spinal needle in the proximal AC. Puncture of the femoral artery was observed with the spinal needle 43% of the time and had the closest average proximity to the femoral artery with a distance of 5.9 mm. There were no vascular punctures using blunt needles, and the average distance from the femoral artery with proximal and distal orientation was 10.2 mm and 15.4 mm, respectively. ConclusionIntraoperative ACB augmentation of PAI appears to be anatomically feasible and safe. There was decreased accuracy and increased risk of vascular puncture using a 3.5-inch spinal needle. A blunt 1.5-inch needle directed toward the distal AC had the highest accuracy while minimizing vascular injury.

An ex vivo liver training model continuously perfused to simulate bleeding for suture skills involved in laparoscopic liver resection: development and validity.

Suture skills are essential to laparoscopic liver resection. The current suture training models are not ideal enough. The aim of this study is to develop and verify a highly simulated-bleeding continuously perfused training model (CPTM) and to evaluate its training efficacy. CPTM was constructed using fresh lamb liver whose portal veins were perfused with red-dyed liquid gelatin. Construct validity of CPTMs was tested in 33 participants with three levels of laparoscopic experience (experts, intermediates, and novices) who were demanded to finish one superficial stitch and one deep stitch for suture hemostasis on CPTMs. The CPTMs were also evaluated by the experts. CPTMs were compared with dry box training models (DBTMs) regarding training efficacy among the novices who were assigned to DBTM and CPTM groups to, respectively, complete a 10-day training on CPTMs or DBTMs. Before and after their assignments, their superficial stitches were assessed by completion time, suture accuracy, and suture knot performance while their deep stitches by completion time and bleeding control. CPTM proved to be construct valid by both superficial and deep stitches. Significant differences were found regarding completion time (763, 271, 174s), suture accuracy (4.4, 1.8, 0.2mm), and suturing knot performance (12.1, 21.5, 22.0) for superficial stitches (p<0.001), as well as regarding completion time (807, 423, 277s) for deep stitches (p<0.001). Positive comments were given by all experts. CPTMs helped novices to acquire laparoscopic suture skills. Their training efficacy was significantly better than that of DBTMs (p<0.05). Learning curves of CPTM group plateaued at the sixth round for superficial stitches and at the seventh round for deep stitches. CPTM offers trainees a highly simulated-bleeding means to acquire advanced laparoscopic suture skills. The suture skills learned on CPTMs may improve significantly at the seventh round.

Endovascular embolization strategy for renal arteriovenous malformations

Renal arteriovenous malformations (AVMs) are rare vascular malformations that cause hematuria. Treatment for renal AVMs has evolved from open nephrectomy to transcatheter arterial embolization (TAE). To retrospectively evaluate efficacy and adverse events of TAE for renal AVMs. We examined 12 patients (three men, nine women; mean age, 56 years) with renal AVM with gross hematuria, who underwent 14 sessions of treatment, using various embolization materials (liquid embolization agents, gelatin sponge, and coils). Among the 12 patients, 10 had cirsoid AVMs, eight of which were high-flow lesions. The remaining two patients had aneurismal AVMs. We assessed technical and clinical success, and also complications. All patients were followed for 7-92 months (mean, 48 months). Technical success was obtained in all patients. Primary clinical success was obtained in all patients; however, recurrence was observed in two patients who were treated with coils alone. A second session of TAE led to the sustained relief of symptoms. Clinical success rate was significant better (P = 0.045) when coils combined with other agents or liquid agents were used, than when only coils were used. No major complications occurred in any of patients; post-embolization syndrome and deterioration of renal function were not observed. TAE treatment was safe, effective, and provided a good outcome, except when only coils were used as the embolization agent.

Development of novel flurbiprofen-loaded solid self-microemulsifying drug delivery system using gelatin as solid carrier

To develop a novel flurbiprofen-loaded solid self-microemulsifying drug delivery system (solid SMEDDS) with improved oral bioavailability using gelatin as a solid carrier, the solid SMEDDS formulation was prepared by spray-drying the solutions containing liquid SMEDDS and gelatin. The liquid SMEDDS, composed of Labrafil M 1944 CS/Labrasol/Transcutol HP (12.5/80/7.5%) with 2% w/v flurbiprofen, gave a z-average diameter of about 100 nm. The flurbiprofen-loaded solid SMEDDS formulation gave a larger emulsion droplet size compared to liquid SMEDDS. Unlike conventional solid SMEDDS, it produced a kind of microcapsule in which liquid SMEDDS was not absorbed onto the surfaces of carrier but formed together with carrier in it. However, the drug was in an amorphous state in it like conventional solid SMEDDS. It greatly improved the oral bioavailability of flurbiprofen in rats. Thus, gelatin could be used as a carrier in the development of solid SMEDDS with improved oral bioavailability of poorly water-soluble drug.

Preparation of microcapsules with self-microemulsifying core by a vibrating nozzle method

Incorporation of drugs in self-microemulsifying systems (SMES) offers several advantages for their delivery, the main one being faster drug dissolution and absorption. Formulation of SMES in solid dosage forms can be difficult and, to date, most SMES are applied in liquid dosage form or soft gelatin capsules. This study has explored the incorporation of SMES in microcapsules, which could then be used for formulation of solid dosage forms. An Inotech IE-50 R encapsulator equipped with a concentric nozzle was used to produce alginate microcapsules with a self-microemulsifying core. Retention of the core phase was improved by optimization of encapsulator parameters and modification of the shell forming phase and hardening solution. The mean encapsulation efficiency of final batches was more than 87%, which resulted in 0.07% drug loading. It was demonstrated that production of microcapsules with a self-microemulsifying core is possible and that the process is stable and reproducible.

인공재배한 흰돌기망태버섯(Dictyophora echinovolvata)의 형태적 특징

본 연구는 농업과학기술원 응용미생물과에 보존된 망태버섯속(Dictyophora sp.)에 대한 인공배양 자실체 및 균사체의 형태적 특징을 관찰하였다. 이 버섯의 알과 성숙한 자실체는 대, 치마, 갓, 대주머니로 이루어져 있다. 알은 타원형으로 내피막, 젤라틴층, 외피막으로 싸여 있으며, 표면에는 백색의 침상 균사돌기로 싸여 있다. 성숙한 자실체는 대주머니 안에 젤라틴층이 액화되어 남아 있으며, 포자는 갓 위에 짙은 녹색의 포자층을 형성하고 있다. 치마는 대주머니 위로 길게 내려오고, 그물망의 눈은 다각형이며, 밤꽃 냄새가 난다. 균사체에서 후막포자 모양의 팽대세포(swelling cell)가 확인되었으며, clamp connection도 존재하였다. 본 연구를 통하여 공시균주 KACC 50650은 Dictyophora echinovolvata로 동정되었으며, 한국명으로는 '흰돌기망태버섯'으로 명명하고자 한다. This study was conducted to investigate morphological characteristics of veiled lady mushroom (Dictyophora sp.). Morphological observation of mycelium showed the presence of chlamydospore-like swelling cells, and typical mycelial champ connections. Fruiting body of the veiled lady mushroom consists of cap, velum, stipe, and vulva. Oval-shaped eggs were surrounded by exodermis, gelatin layers and endodermis, and the fruiting bodies remained inside volva as liquid gelatin layer. Dark green spore layer was formed at the top of cap. The surface eggs in the cultivated veiled lady mushroom was covered with white needle-shaped mycelial projection that was oval in shape. The velum of fruiting body stretched down to the top of volva. The net was regularly shaped, and smelled like fragrance with chestnut flower. The strain KACC 50650 was identified as Dictyophora echinovolvata based on the morphology of eggs and fruiting bodies, and named as Huin-Dol-Gi-Mang-Tae mushroom in Korean.

Phase equilibria and mechanical properties of gel-like water–gelatin–locust bean gum systems

The establishment of phase equilibrium in aqueous gelatin–locust bean gum (LBG) systems in the process of cooling from 313 to 291 K in specific conditions, passes ahead of the gelation process . This allows the suggestion that macrostructure and mechanical properties of the system can be predicted on the basis of knowledge of its phase diagram, obtained for the liquid gelatin–LBG systems comprising gelatin molecular aggregates. Textural and rheological analysis of gel-like gelatin–LBG systems demonstrate the effect of two factors determining their mechanical properties and acting opposite each other when the concentration of LBG in the system increases: concentration of gelatin by LBG in the process of phase separation, and decrease in the density of the gel network.