Gelatin-based Materials Research Articles

Design of gelatin-based bionic device for neural computing applications

This study introduces an approach to the development of resistive random-access memory (RRAM) devices by utilizing gelatin-based materials and incorporating an ultrathin Al2O3 interface layer fabricated using atomic layer deposition (ALD). The integration of the ALD technology for Al2O3 deposition ensures precise control over the layer thickness and quality, contributing to enhanced device uniformity and stability. The AGAI device can withstand more than 200 switching cycles while maintaining a high ON/OFF ratio exceeding 103, and it also successfully emulates synaptic plasticity characteristics, including long-term synaptic plasticity and short-term synaptic plasticity, as demonstrated by their responses to paired-pulse facilitation and paired-pulse depression, respectively, thereby validating their potential for neural computing applications. Additionally, the hybrid conduction mechanism in the AGAI device, involving aluminum and oxygen vacancy filaments, provides remarkable control over the switching process, leading to repeatability in synaptic characteristics and resistance states. These capabilities introduce new possibilities for the development of neuromorphic computing systems, which aim to mimic the functionality of the human brain in processing and storing information.

Flexible, self-healing, and degradable polymeric dielectrics cross-linked through metal–ligand for resistive memory device

The ability to self-heal is a crucial feature in nature, where living organisms can repair themselves when subjected to minor injuries. With an increasing emphasis on environmental sustainability, the concept of biomimetic self-healing polymeric materials has emerged as a prominent trend, promising to significantly extend the lifespan and reliability of products. Studies have shown that one-third of proteins in living organisms require metal cofactors to function properly. It is known that protein-metal interactions can enhance the performance of certain biomaterials, and different choices of metals and ligands can create diverse material properties, influencing characteristics such as hardness, toughness, adhesion, and self-healing abilities. Gelatin is a natural polymer derived from the hydrolysis of collagen, and its unique amino acid structure has led to a wide range of applications. In this research, by introducing aluminum ions that form metal coordination complexes with the carboxyl groups in gelatin, an elastic network with self-healing properties was constructed. This gelatin-based material was utilized as an insulating layer in resistive switching devices. Furthermore, by employing a gelatin substrate of the same composition, the device demonstrated strong interfacial adhesion. The device based on the self-healing gelatin film exhibited excellent electrical performance and mechanical properties. Even after self-healing, it maintained a high ON/OFF ratio of up to 105 and a concentrated distribution of switching parameters. Supported by compelling physical and electrical evidence, this study showcases significant development opportunities for biomimetic materials in green electronic devices.

Acoustic velocity and stability of tissue-mimicking echogenic materials for ultrasound training phantoms

Purpose. High-fidelity mannequins are increasingly used to train the medical staff on many medical procedures. Lately, a new challenge regarding echogenic materials to build ultrasound-responding phantoms has emerged. The challenge is to find materials with a suitable combination of ultrasound velocity and consistency to the touch. Methods. Bibliographic research was performed to identify materials with promising stiffness, shape retention, and ultrasound velocity combinations. As-standardized-as-possible specimens were realized and tested using an A-mode ultrasound machine to evaluate the US velocity through them. Four differently doped silicones, five gelatin-based materials, five synthetic gelatins, and a 3D printable resin were included in the study. After being tested, the materials were monitored for 12 days to assess their durability and shape retention and tested again to evaluate the ultrasound velocity’s stability. In the paper, the results of the characterization and follow-up of the materials are presented. Results. Outcomes show that gelatins are exceptional soft tissue-mimicking materials in terms of ultrasound velocity and consistency to the touch, but are poor in terms of overtime stability and therefore suitable for disposable short-term phantoms only. Doped silicones present lower ultrasound velocity compared to the reference value of 1540 m/s found in the literature, but excellent overtime stability, and shape retention properties. Values close to biological ones were also given by the Elastic 50A and by polyvinyl chloride plastisol. Conclusion. The paper gives a quantitative overview of the fidelity of both already-in-use and non-conventional materials, focusing on the ultrasound velocity value through them and their longevity in terms of macroscopically observed dehydration, shape retention, and bacterial onset.

Bioprinting of gelatin-based materials for orthopedic application.

Bio-printed hydrogels have evolved as one of the best regenerative medicine and tissue engineering platforms due to their outstanding cell-friendly microenvironment. A correct hydrogel ink formulation is critical for creating desired scaffolds that have better fidelity after printing. Gelatin and its derivatives have sparked intense interest in various biomedical sectors because of their biocompatibility, biodegradability, ease of functionalization, and rapid gelling tendency. As a result, this report emphasizes the relevance of gelatin-based hydrogel in fabricating bio-printed scaffolds for orthopedic applications. Starting with what hydrogels and bio-printing are all about. We further summarized the different gelatin-based bio-printing techniques explored for orthopedic applications, including a few recent studies. We also discussed the suitability of gelatin as a biopolymer for both 3D and 4D printing materials. As extrusion is one of the most widely used techniques for bio-printing gelatin-based, we summarize the rheological features of gelatin-based bio-ink. Lastly, we also elaborate on the recent bio-printed gelatin-based studies for orthopedics applications, the potential clinical translation issues, and research possibilities.

Effect of Gelatin-Based Hemostats on Fibroblasts and Relevant Growth Factors in Wound Healing.

Gelatin-based hemostats have been used in various surgical fields and showed advantageous effects on central aspects of wound healing when compared to cellulose-based hemostats. Nevertheless, the influence of gelatin-based hemostats on wound healing has not been fully explored yet. Hemostats were applied to fibroblast cell cultures for 5, 30, 60 min, 24 h, 7 and 14 days and measurements were taken at 3, 6, 12, 24 h and 7 or 14 days, respectively. Cell proliferation was quantified after different exposure times and a contraction assay was conducted to measure the extent of the extracellular matrix over time. We further assessed quantitative levels of vascular endothelial growth factor and basic fibroblast growth factor using enzyme-linked immunosorbent assay. Fibroblast counts decreased significantly at 7 and 14 days independent of the application duration (p < 0.001 for 5 min application). The gelatin-based hemostat did not have a negative impact on cell matrix contraction. After application of gelatin-based hemostat, the basic fibroblast growth factor did not change; yet, the vascular endothelial growth factor significantly increased after a prolonged 24 h application time when compared to controls or to a 6 h exposure (p < 0.05). Gelatin-based hemostats did not impair contraction of the extracellular matrix or growth factor production (vascular endothelial growth factor and basic fibroblast growth factor), while cell proliferation diminished at late time points. In conclusion, the gelatin-based material seems to be compatible with central aspects of wound healing. For further clinical assessment, future animal and human studies are necessary.

Gelatin-based anticancer drug delivery nanosystems: A mini review.

Drug delivery nanosystems (DDnS) is widely developed recently. Gelatin is a high-potential biomaterial originated from natural resources for anticancer DDnS, which can effectively improve the utilization of anticancer drugs and reduce side effects. The hydrophilic, amphoteric behavior and sol-gel transition of gelatin can be used to fulfill various requirements of anticancer DDnS. Additionally, the high number of multifunctional groups on the surface of gelatin provides the possibility of crosslinking and further modifications. In this review, we focus on the properties of gelatin and briefly elaborate the correlation between the properties and anticancer DDnS. Furthermore, we discuss the applications of gelatin-based DDnS in various cancer treatments. Overall, we have summarized the excellent properties of gelatin and correlated with DDnS to provide a manual for the design of gelatin-based materials for DDnS.

Cross-linking of Gelatin with Epichlorohydrin in a Sodium-Acetate-Trihydrate/Urea Deep Eutectic Solvent System

To improve the cross-linking efficiency of gelatin molecules, sodium acetate trihydrate/urea deep eutectic solvent with 30% water (SAT/U-DES30W, based on DES weight) was proposed as the solvent of gelatin in this paper. The system could overcome the gelation effect of gelatin at low temperature and expose more active groups of gelatin molecules, resulting in better cross-linking effect. Firstly, the optimal reaction concentration of epichlorohydrin (ECH) was determined by boiling water solubility of cross-linking products, and the cross-linking efficiency of gelatin under two systems was judged together with the Glass transition temperature method. Secondly, the water resistance of the cross-linked product was investigated by swelling capacity and water contact angle. The water absorption rate of GEW and GEDES decreased from 4614% to 1500% and 929% at 12 h, respectively, and the water contact angle also obviously decreased, indicating that the cross-linking efficiency of gelatin under DES system was higher. Finally, the cross-linking mechanism of gelatin and ECH were discussed and it was found the thermal stability of GEDES was significantly improved, which would provide a theoretical basis for gelatin-based materials.

Gelatin-based films and mats as electro-sensoactive layers for monitoring volatile compounds related to meat spoilage

Gas sensors are an emerging technology that contributes to the quality and freshness assessment in the food sector. Among the possible techniques to prepare gas sensors, film casting and electrospinning are considered easy and relatively simple methods. The present study aims at investigating the effect of processing on structural, morphological, thermal, and sensitivity properties of gelatin (GEL) based films and mats incorporated or not with anthocyanin (ATH) as a function of the presence of volatile compounds associated with meat spoilage. Both electrospinning process and ATH incorporation induced structural changes in gelatin-based materials, such as decreasing crystallinity as a function of the intermolecular interactions and consequent changes in materials' thermal properties. The sensitivity values of Gel and Gel-ATH mats were respectively, 54% and 45% higher in comparison with their corresponding drop-casting layers. Sensor response showed a prominent correlation with total volatile basic nitrogen. The results suggest the development of a new responsive and biocompatible material for meat quality assessment.

Analysis of gelatin secondary structure in gelatin/keratin-based biomaterials

The possibility of using protein-based materials as cellular scaffold strongly depends on protein conformation, and several attempts have been made by researchers to obtain scaffold with morphology miming the extracellular matrix. It is widely recognized that the secondary structure of proteins affects the mechanical and biological properties of protein-based scaffolds. However, few studies have been published, and an exhaustive explanation is still missing. In this work the study of the gelatin structure in gelatin-based materials and the investigation of the possible correlations between structure, mechanical and biological features is reported.We have examined how the secondary structure of gelatin is affected (i) by the process used to obtain the biomaterials (solvent casting vs. electrospinning), (ii) by the concentration of cross linker (3-(Glycidyloxypropyl)trimethoxysilane) (GPTMS), and (iii) by the raw keratin extract added. Gelatin electrospun materials have shown a content of ordered structure higher than gelatin casted films, likely due to the random coil – α-helix transition occuring during electrospinning. GPTMS gives a decrease of ordered structures in gelatin casted films (random structure increasing from 20% to 60%), while it does not affect the percentage of ordered structure in electrospun samples. In the gelatin/keratin electrospun biomaterials, the presence of keratin produces a decrease of α-helix content from 31% to 2–15% and an increase of β-structures, promoting the conversion from antiparallel to parallel β-sheet. The structure of gelatin affects the mechanical performances of biomaterials. In gelatin/keratin electrospun biomaterials we have found a positive correlation between failure strain and helix conformation and a negative correlation with β-structures. Elastic modulus has opposite correlations. All gelatin-based biomaterials have been tested as scaffold for pre-osteoblastic cells showing good biocompatibility for both casted films and electrospun biomaterials.

Central composite design optimization of active and physical properties of food packaging films based on chitosan/gelatin/pomegranate peel extract

Chitosan and gelatin-based materials containing pomegranate peel extract were prepared for potential application as food packaging materials. An optimized composition of 0.8% chitosan, 0.2% gelatin and 1 mg g-1 of extract was chosen with the aid of a central composite design, presenting low viscosity (8.36 ± 0.20 Pa s) and solubility (26.00 ± 5.50%), as well as an expressive inhibition halo against Botrytis cinerea (6.17 ± 0.36 mm). The interaction between the polymeric matrix and the extract was confirmed by spectroscopic and morphological analysis. Rheologically, the optimized formulation was more resistant to deformation and shear (activation energy increased by almost 5 kJ mol-1) than the formulation without the extract. The use of pomegranate peel extract changed the film color, reduced its solubility (by more than 5%), increased mechanical resistance (tensile strength increased by 15 mPa), and improved light barrier properties by 30%. The extract also imparted antioxidant activity to the film, which was able to inhibit 20% of DPPH (2,2-diphenyl-1-picrylhydrazyl) radical at 38 mg mL-1. The optimized composition also showed inhibitory bacterial properties (31.2 and 125 µg mL-1) against S. aureus and S. enteritidis, respectively. Thus, the optimized film exhibited interesting characteristics for food packaging applications, many of them brought by the use of pomegranate peel extract, which highlights the valuable contribution of this agro-industrial waste to the properties of the polymeric films.

Novel Gelatin-based Bioplastic Materials Designed to Replace Polystyrene and Polypropylene in Single-use Hard Plastics

Novel Gelatin-based Bioplastic Materials Designed to Replace Polystyrene and Polypropylene in Single-use Hard Plastics

Gelatin-based cellular solids: Fabrication, structure and properties

Although most cellular polymers are made from thermoplastics using different foaming technologies, gelatin and many other natural polymers can form hydrogels and convert them to cellular solids using various techniques, many of which differ from traditional plastic foaming, and so does their resulting structures. Cellular solids from natural hydrogels are porous materials that often exhibit a combination of desirable properties, including high specific surface area, biochemical activity, as well as thermal and acoustic insulation properties. Among natural hydrogels, gelatin-based porous materials are widely explored due to their availability, biocompatibility, biodegradability and relatively low cost. In addition, gelatin-based cellular solids have outstanding properties and are currently subject to increasing scientific research due to their potential in many applications, such as biocompatible cellular materials or biofoams to facilitate waste treatment. This article aims at providing a comprehensive review of gelatin cellular solids processing and their processing-properties-structure relationship. The fabrication techniques covered include aerogels production, mechanical foaming, blowing agents use, 3D printing, electrospinning and particle leaching methods. It is hoped that the assessment of their characteristics provides compiled information and guidance for selecting techniques and optimization of processing conditions to control material structure and properties to meet the needs of the finished products.

Composite Materials Based on Gelatin and Iron Oxide Nanoparticles for MRI Accuracy.

The majority of recent studies have focused on obtaining MRI materials for internal use. However, this study focuses on a straightforward method for preparing gelatin-based materials with iron oxide nanoparticles (G–Fe2O3 and G–Fe3O4) for external use. The newly obtained materials must be precisely tuned to match the requirements and usage situation because they will be in close touch with human/animal skin. The biocompatible structures formed by gelatin, tannic acid, and iron oxide nanoparticles were investigated by using FTIR spectroscopy, SEM-EDAX analysis, and contact angle methods. The physico-chemical properties were obtained by using mechanical investigations, dynamic vapor sorption analysis, and bulk magnetic determination. The size and shape of iron oxide nanoparticles dictates the magnetic behavior of the gelatin-based samples. The magnetization curves revealed a typical S-shaped superparamagnetic behavior which is evidence of improved MRI image accuracy. In addition, the MTT assay was used to demonstrate the non-toxicity of the samples, and the antibacterial test confirmed satisfactory findings for all G-based materials.

Green Robotics: Toward Realization of Environmentally Friendly Soft Robots

An important research direction in soft robotics could be the realization of environmentally friendly “green” soft robots that are biodegradable, sustainable, and recyclable. We present recent findings from our ongoing research on biodegradable robotic devices made of gelatin-based materials and discuss future directions in this contribution.

Gelatin-based packaging material incorporated with potato skins carbon dots as functional filler

Carbon dots (CD) were developed via hydrothermal synthesis using potato peel as functional fillers for food packaging films. The CD showed strong antioxidant and antimicrobial activity with low cytotoxicity as more than 80% of mouse fibroblast L929 cells survived even when exposed to 500 μg/mL for 72 h. The CD was used as a functional filler for preparing a gelatin-based functional film, and it was uniformly dispersed in biopolymer, indicating a compatible packaging film. The FTIR result showed no change in the chemical structure, but an H-bond was apparent between the CD and gelatin. The addition of CD produced a highly transparent film with significant improvement in the water vapor permeability (by 28%) and hydrophobicity (by 9% and 13%) properties of the gelatin film without much changing of the mechanical properties. The CD-added gelatin films indicated UV-barrier property and strong antioxidant activity. Moreover, the antibacterial efficacy increased significantly. Therefore, the CD-added gelatin films have great potential as a value-added, low-cost, safe, and functional nanofiller for the preparation of packaging applications.

Single-Chain Mechanical Properties of Gelatin: A Single-Molecule Study.

Gelatin is an important natural biological resource with a wide range of applications in the pharmaceutical, industrial and food industries. We investigated the single-chain behaviors of gelatin by atomic force microscopy (AFM)-based single-molecule force spectroscopy (SMFS), and found that gelatin exists as long chains by fitting with the M-FJC model. By comparing the single-chain elasticity in a nonpolar organic solvent (nonane) and DI water, it was surprising to find that there was almost no difference in the single-chain elasticity of gelatin in nonane and DI water. Considering the specificity of gelatin solubility and the solvent size effect of nonane molecules, when a single gelatin chain is pulled into loose nonane, dehydration does not occur due to strong binding water interactions. Gelatin chains can only interact with water molecules at high temperatures; therefore, no further interaction of single gelatin chains with water molecules occurred at the experimental temperature. This eventually led to almost no difference in the single-chain F–E curves under the two conditions. It is expected that our study will enable the deep exploration of the interaction between water molecules and gelatin and provide a theoretical basis and experimental foundation for the design of gelatin-based materials with more functionalities.

A Long-Lasting Textile-Based Anatomically Realistic Head Phantom for Validation of EEG Electrodes.

During the development of new electroencephalography electrodes, it is important to surpass the validation process. However, maintaining the human mind in a constant state is impossible which in turn makes the validation process very difficult. Besides, it is also extremely difficult to identify noise and signals as the input signals are not known. For that reason, many researchers have developed head phantoms predominantly from ballistic gelatin. Gelatin-based material can be used in phantom applications, but unfortunately, this type of phantom has a short lifespan and is relatively heavyweight. Therefore, this article explores a long-lasting and lightweight (−91.17%) textile-based anatomically realistic head phantom that provides comparable functional performance to a gelatin-based head phantom. The result proved that the textile-based head phantom can accurately mimic body-electrode frequency responses which make it suitable for the controlled validation of new electrodes. The signal-to-noise ratio (SNR) of the textile-based head phantom was found to be significantly better than the ballistic gelatin-based head providing a 15.95 dB ± 1.666 (±10.45%) SNR at a 95% confidence interval.

New algorithm for the elucidation of functional properties of gelatin-based materials

In the present work, fish gelatin was employed to develop renewable and biodegradable materials, reducing environmental problems associated with conventional petroleum-based materials. Glycerol was used as plasticizer and gallic acid was added in order to enhance the functional properties of the material. L-fuzzy concept analysis was applied for modelling the formulations and properties of the films. These new methodology is used in the design of the material avoiding the traditional inefficient trial an error approach usually employed. Two applications of the developed bio-based material were analyzed: fatty food packaging application in food area and wound healing in the biomedical field. The functional properties requirements of water contact angle (CA), water vapour transmission rate (WVTR), colour L* and b* values, tensile strength (TS), elongation at break (EB) and gloss values were specified for both applications. Applying the proposed algorithm, the required formulations were estimated and the experimental results showed a high accordance with the predicted values of the final properties, as well as with the requirements. This analysis allowed finding the required formulations in a highly cost-effective way.

Toward Adipose Tissue Engineering Using Thiol-Norbornene Photo-Crosslinkable Gelatin Hydrogels.

Nowadays, breast implants, lipofilling, and microsurgical free tissue transfer are the most often applied procedures to repair soft tissue defects resulting from mastectomies/lumpectomies following breast cancer. Due to the drawbacks and limitations associated with these conventional clinical practices, there is a need for alternative reconstructive strategies. The development of biomimetic materials able to promote cell proliferation and adipogenic differentiation has gained increasing attention in the context of adipose reconstructive purposes. Herein, thiol-norbornene crosslinkable gelatin-based materials were developed and benchmarked to the current commonly applied methacryloyl-modified gelatin (GelMA) with different degrees of substitutions focussing on bottom-up tissue engineering. The developed hydrogels resulted in similar gel fractions, swelling, and in vitro biodegradation properties compared to the benchmark materials. Furthermore, the thiol-ene hydrogels exhibited mechanical properties closer to those of native fatty tissue compared to GelMA. The mechanical cues of the equimolar GelNB DS55% + GelSH DS75% composition resulted not only in similar biocompatibility but also, more importantly, in superior differentiation of the encapsulated cells into the adipogenic lineage, as compared to GelMA. It can be concluded that the photo-crosslinkable thiol-ene systems offer a promising strategy toward adipose tissue engineering through cell encapsulation compared to the benchmark GelMA.

Gelatin–Poly (γ-Glutamic Acid) Hydrogel as a Potential Adhesive for Repair of Intervertebral Disc Annulus Fibrosus

Study Design. An in vitro experimental study testing a Gelatin–poly (γ-glutamic acid) hydrogel for disc repair. Objective. To evaluate the cytocompatibility and degradability of the above mentioned hydrogel for intervertebral disc annular fibrosis (AF) repair. Summary of Background Data. No repair strategies for correcting annular defects in lumbar discectomy have been clinically well recognized. Exogenous supplementation of regenerative materials to fill defects is a minimally invasive way to restore compromised mechanical properties. The injected materials, most commonly gelatin-based materials with cross-linking agents, serve as sealants and as a scaffold for incorporating biomaterials for augmentation. However, cytotoxicity of hydrogel crosslinking agents is of concern in developing viable materials. Methods. This in vitro experimental study evaluated a newly developed gelatin-based hydrogel for intervertebral disc AF repair. Mechanical strength was augmented by γ-PGA, and 1-(3-dimethylaminopropyl)-3-ethyl-carbodiimide hydrochloride (EDC) was used for material crosslinking. Isolated bovine tail intervertebral discs (IVDs) were used to test the hydrogel, and hydrogel surface monolayer AF cell culture was used to investigate efficacy in hydrogel constructs of different EDC concentrations. Cell metabolic activity was evaluated with Alamar blue assay, cell viability assay with live/dead stain, and sulfated glycosaminoglycan (GAG) and double strain DNA were quantified to evaluate proliferation of implanted cells and synthesis of extracellular matrix (ECM) proteins. Results. EDC concentrations from 10 to 40 mM resulted in significant decreases in AF cell proliferation without obvious influence on cell viability. Higher EDC concentrations resulted in decreased percentage of Alamar blue reduction and GAG and DNA concentration, but did not affect GAG/DNA and live–dead ratios. Degradation tests revealed that higher EDC concentrations decreased the hydrogel degradation rate. Conclusion. The developed gelatin–poly (γ-PGA) hydrogel with 20 mM EDC concentration provides an effective gap-filling biomaterial with good cytocompatibility, suggesting substantial promise for use as a sealant for small AF defects. Level of Evidence: N/A