Gelatin Matrix Research Articles

Self‐Healable, Recyclable Anisotropic Conductive Films of Liquid Metal‐Gelatin Hybrids for Soft Electronics

AbstractThis paper reports an unconventional approach for the formation of self‐healable and recyclable anisotropic conductive films (ACFs) using soft composites of gelatin hydrogels and liquid metals (LMs). The capsules of LMs dispersed inside the gelatin matrix can present satisfactory anisotropic conductance for electrical connections of vertically aligned, fine electrodes at room temperature by applying compressive pressures. The minimization of the capsule size as well as the softness of these LM‐gelatin hybrid ACFs enables high‐resolution integrations of deformable electronic systems, which can increase the integrity of freeform devices. In addition, the good fluidity of LMs and strong hydrogen bonding in gelatin enable these ACFs to be self‐healable at ambient conditions and even recyclable with no significant degradations in either their original electrical or mechanical properties. The utilization of these ACFs to integrate multiple interconnections of micro‐light‐emitting diode arrays on a soft elastomeric substrate demonstrates a stretchable display with its reliable operations during mechanical deformations, suggesting a promising strategy for next‐generation freeform and eco‐friendly green electronics.

Performance of Gelatin Films Reinforced with Cloisite Na+ and Black Pepper Essential Oil Loaded Nanoemulsion.

The concern about consuming eco-friendly products has motivated research in the development of new materials. Therefore, films based on natural polymers have been used to replace traditional polymers. This study consists of a production of films based on gelatin reinforced with black pepper essential oil-loaded nanoemulsions and Cloisite Na+. The films were characterized by water vapor permeability, mechanical and thermal properties, surface contact angle, X-ray diffraction and scanning electron microscopy. It was observed that the films containing the nanoemulsion have higher permeability values and an increase in their mechanical resistance. The addition of nanoclay contributed to an increase in the surface hydrophobicity of the film and an increase in the tensile strength, at break, by about 150%. The addition of essential oil nanoemulsions led to an increase in thermal stability. The presence of clay dispersion contributed to the formation of a surface that was slightly rougher and grainier. The addition of the black pepper essential oil nanoemulsion resulted in an increase in porosity of the gelatin matrix. Through X-ray diffraction analysis, it was possible to conclude that both the polymeric gelatin matrix and the essential oils nanoemulsion are intercalated with the clay dispersion.

Active and Robust Composite Films Based on Gelatin and Gallic Acid Integrated with Microfibrillated Cellulose.

Background: Gelatin is a renewable, biodegradable, and inexpensive food polymer. The insufficient mechanical and functional properties of gelatin-based films (GBF) restrict their commercial application in food packaging. This work proposed a facile strategy to prepare an active and robust GBF that has the potential to be used in food packaging. Methods: A strong and active GBF was prepared based on the principle of supramolecular chemistry via the incorporation of gallic acid (GA) as an active crosslinking agent and of microfibrillated cellulose (MFC) as a reinforcing agent. Results: Under the appropriate concentration (1.0 wt%), MFC was evenly dispersed in a gelatin matrix to endow the film with low surface roughness and compact structure. Compared with the GF, the tensile strength and elongation at break of the resultant film reached 6.09 MPa and 213.4%, respectively, representing the corresponding improvement of 12.8% and 27.6%. Besides, a significantly improved water vapor barrier (from 3.985 × 10−8 to 3.894 × 10−8 g·m−1·Pa−1·s−1) and antioxidant activity (from 54.6% to 86.4% for ABTS radical scavenging activity; from 6.0% to 89.1% for DPPH radical scavenging activity) of GBFs were also observed after introducing the aromatic structure of GA and nano-/microfibrils in MFC. Moreover, the UV blocking performance and thermal stability of GGF and GGCFs were also enhanced. Conclusions: this work paves a promising way toward facile preparation of multifunctional GBFs that have great potential to be used in fabricating active and safe food packaging materials for food preservation.

Reinforcement of Alginate-Gelatin Hydrogels with Bioceramics for Biomedical Applications: A Comparative Study.

This study states the preparation of novel ink with potential use for bone and cartilage tissue restoration. 3Dprint manufacturing allows customizing prostheses and complex morphologies of any traumatism. The quest for bioinks that increase the restoration rate based on printable polymers is a need. This study is focused on main steps, the synthesis of two bioceramic materials as WO3 and Na2Ti6O13, its integration into a biopolymeric-base matrix of Alginate and Gelatin to support the particles in a complete scaffold to trigger the potential nucleation of crystals of calcium phosphates, and its comparative study with independent systems of formulations with bioceramic particles as Al2O3, TiO2, and ZrO2. FT-IR and SEM studies result in hydroxyapatite’s potential nucleation, which can generate bone or cartilage tissue regeneration systems with low or null cytotoxicity. These composites were tested by cell culture techniques to assess their biocompatibility. Moreover, the reinforcement was compared individually by mechanical tests with higher results on synthesized materials Na2Ti6O13 with 35 kPa and WO3 with 63 kPa. Finally, the integration of these composite materials formulated by Alginate/Gelatin and bioceramic has been characterized as functional for further manufacturing with the aid of novel biofabrication techniques such as 3D printing.

Dual-functional intelligent gelatin based packaging film for maintaining and monitoring the shrimp freshness

Dual-functional intelligent food packaging film for maintaining and monitoring food freshness has gained a growing number of attentions in food field. Herein, we introduced a smart gelatin-based packaging film integrating real-time monitoring and maintaining food freshness. In detail, through a two-step de-solvation method, gelatin particles were fabricated and further used for preparing oil-in-water (O/W) lavender essential oil Pickering emulsions (LEOPs). LEOPs and Alizarin (ALI) were integrated into the gelatin matrix of the three-dimensional (3D) network via intermolecular hydrogen bonding and dehydration condensation, respectively, to develop intelligent active packaging films (GL-ALI-LEOPs). GL-ALI-LEOPs exhibited excellent antibacterial and antioxidant properties and a sensitive, reversible, and rapid response to pH/NH3. Benefiting from good mechanical properties, light barrier properties and hydrophobicity of modified gelatin-based films, GL-ALI-LEOPs are readily processed into food packaging bags and smart tags. GL-ALI-LEOPs were successfully employed as an eco-friendly, low-cost, bacteriostatic and pH/NH3 quick-responsive smart trademark for real-timely monitoring and maintaining the freshness of shrimp.

Isolation of thermostable cellulose II nanocrystals and their molecular bridging for electroresponsive and pH-sensitive bio-nanocomposite

Sustainable, economical, and green extraction of cellulose Ⅱ nanocrystals from lignocellulose under mild conditions is still challenging since the highly recalcitrant nature of lignocellulose. Herein, a sustainable system using ammonium persulfate (APS)-catalyzed deep eutectic solvent (ADES) was developed to produce functional cellulose Ⅱ nanocrystals (CNCs) with a high yield of 82.3 %. The obtained CNCs had excellent thermal stability (>350 ℃), high crystallinity of 76.6 % with surface carboxyl groups, and superior dispersion stability. CNCs played a role of both molecular bridging and nano-sized effect in gelatin matrix, which combined with gelatin tightly through multiple hydrogen bonds to prepare bio-nanocomposite films with outstanding electric-responsiveness and pH-sensitivity. It was proved that CNCs had remarkable reinforcing potential and effective stress transfer capacity, contributing to a 187 % enhancement in tensile strength and an approximately 110 % increase in Young’s modulus of the formed CNCs/gelatin nanocomposite films when 0.5 wt % CNCs was loaded. Therefore, the study may open the door for developing a green and sustainable avenue to produce functional CNCs, and is of great significance for the building of CNCs-based functional nanocomposites.

369 An Adipose-derived Stem Cell-engineered matrix represents a promising treatment for chronic wounds

Mesenchymal stem cell-based therapies are emerging as promising approach to promote cutaneous regeneration of chronic wounds. We assessed here the regenerative potential of a patch concentrating mesenchymal stem cells extracted from the human fat, i.e. adipose-derived stem cells (ASC), in a gelatin matrix. ASC cultures were derived from the subcutaneous abdominal fat of four patients. Principal component analysis on microarray data revealed that ASC grown within the patch upregulate the transcription of genes important for wound healing, including VEGF, CXCL12 and FGF7.

The sole and combined effects of gelatin-thrombin matrix and freeze-dried bone allograft on early bone healing.

Gelatin-thrombin matrix (GTM) is a hemostatic agent with applications in maxillofacial surgery consisting of human-derived thrombin and bovine-derived gelatin matrix. The aim of this study was to evaluate the efficacy of GTM alone or with freeze-dried bone allograft (FDBA) in improving early bone healing. Forty-six adult male Sprague-Dawley rats were used. All animals were randomly assigned to a control group (n = 4) and three study groups (n = 14). Each group was divided into two subgroups for histomorphometric and histological analyses at weeks 1 and 4. The new bone formation, inflammation, fibrosis, necrosis, foreign body reaction, and bone healing scores were evaluated based on the histopathological findings. Multiple comparisons were performed using the Kruskal-Wallis test. Variables that were not normally distributed were evaluated using the Mann-Whitney U test. At 1 week, the GTM + FDBA group showed less bone formation (mean ± SD: 0.08 ± 0.03 mm2), compared with the study and control groups (FDBA: 0.15 ± 0.06 mm2; GTM: 0.13 ± 0.06 mm2). At 4 weeks, the GTM group (0.48 ± 0.1 mm2) showed more bone formation than the GTM + FDBA group (0.33 ± 0.17 mm2). Foreign body reactions were observed at weeks 1 and 4 in all GTM-containing groups. Within the limitations of this study, GTM group did not show a significant difference in bone formation compared with the control group. GTM did not inhibit bone healing at 1 and 4 weeks, and no significant difference was observed compared with the control groups. GTM was more effective for bone healing when administered without FDBA. GTM is considered safe when bone hemorrhage is encountered.

Sensitized fluorescence and superluminescence of a dye in a functional chitosan–gelatin matrix

A method for the formation of a functional biopolymer matrix based on specific mixing of chitosan and gelatin is proposed. It makes it possible to obtain the binding complexes of organic dyes such as eosin (energy donor) and rhodamine C (acceptor) with chitosan that are advantageous for the realization of inductive-resonant electron excitation energy transfer between these dyes. An efficient sensitized steady-state fluorescence of rhodamine C and superluminescence of this dye under pulsed excitation were observed in this system. The obtained results can be used for the development of two-component solid-state dye lasers.

Hemostatic efficacy of two topical adjunctive hemostats in a porcine spleen biopsy punch model of moderate bleeding

Topical hemostatic agents have become essential tools to aid in preventing excessive bleeding in surgical or emergency settings and to mitigate the associated risks of serious complications. In the present study, we compared the hemostatic efficacy of SURGIFLO® Hemostatic Matrix Kit with Thrombin (Surgiflo—flowable gelatin matrix plus human thrombin) to HEMOBLAST™ Bellows Hemostatic Agent (Hemoblast—a combination product consisting of collagen, chondroitin sulfate, and human thrombin). Surgiflo and Hemoblast were randomly tested in experimentally induced bleeding lesions on the spleens of four pigs. Primary endpoints included hemostatic efficacy measured by absolute time to hemostasis (TTH) within 5 min. Secondary endpoints included the number of product applications and the percent of product needed from each device to achieve hemostasis. Surgiflo demonstrated significantly higher hemostatic efficacy and lower TTH (p < 0.01) than Hemoblast. Surgiflo-treated lesion sites achieved hemostasis in 77.4% of cases following a single product application vs. 3.3% of Hemoblast-treated sites. On average, Surgiflo-treated sites required 63% less product applications than Hemoblast-treated sites (1.26 ± 0.0.51 vs. 3.37 ± 1.16). Surgiflo provided more effective and faster hemostasis than Hemoblast. Since both products contain thrombin to activate endogenous fibrinogen and accelerate clot formation, the superior hemostatic efficacy of Surgiflo in the porcine spleen punch biopsy model seems to be due to Surgiflo’s property as a malleable barrier able to adjust to defect topography and to provide an environment for platelets to adhere and aggregate. Surgiflo combines a flowable gelatin matrix and a delivery system well-suited for precise application to bleeding sites where other methods of hemostasis may be impractical or ineffective.

Stem Cell Microarrays for Assessing Growth Factor Signaling in Engineered Glycan Microenvironments.

Extracellular glycans, such as glycosaminoglycans (GAGs), provide an essential regulatory component during the development and maintenance of tissues. GAGs, which harbor binding sites for a range of growth factors (GFs) and other morphogens, help establish gradients of these molecules in the extracellular matrix (ECM) and promote the formation of active signaling complexes when presented at the cell surface. As such, GAGs have been pursued as biologically active components for the development of biomaterials for cell-based regenerative therapies. However, their structural complexity and compositional heterogeneity make establishing structure-function relationships for this class of glycans difficult. Here, a stem cell array platform is described, in which chemically modified heparan sulfate (HS) GAG polysaccharides are conjugated to a gelatin matrix and introduced into a polyacrylamide hydrogel network. This array allowed for direct analysis of HS contributions to the signaling via the FGF2-dependent mitogen activated protein kinase (MAPK) pathway in mouse embryonic stem cells. With the recent emergence of powerful synthetic and recombinant technologies to produce well-defined GAG structures, a platform for analyzing both growth factor binding and signaling in response to the presence of these biomolecules will provide a powerful tool for integrating glycans into biomaterials to advance their biological properties and applications.

Regeneration of rat periodontium by cementum protein 1-derived peptide.

Cementum protein 1 (CEMP1) has the capacity to promote differentiation of periodontal ligament (PDL) cells toward a cementoblastic phenotype in vitro and bone regeneration in vivo. In this study, we tested the capabilities of a synthetic cementum protein 1-derived peptide, MGTSSTDSQQAGHRRCSTSN (CEMP1-p1), to promote regeneration of periodontal structures in a periodontal fenestration defect in rats. Fenestration defects were created using an extra-oral approach in the buccal aspect of the mandibular first molar roots. Eighteen male Wistar rats were divided into three groups. Two controls (defects non-treated or defects treated with a gelatin matrix scaffold [GMS] only) and the experimental group treated with 5µg/dose of CEMP1-p1 embedded in GMS. After 28days, the animals were sacrificed, and the mandibles processed for histopathological examination. Expression of cementum proteins, cementum attachment protein (CAP), CEMP1, integrin binding sialoprotein (IBSP), and osteocalcin (OCN), was assessed using immunofluorescence. The formation of new cementum, bone, and PDL fibers were compared between control and experimental groups. The histological analysis revealed that the control group without any treatment new cementum or oriented PDL fibers were not observed. However, the presence of newly bone was detected. In the control group treated with GMS, new cementum formation was not detectable, the PDL fibers were oriented parallel to the longitudinal root axis, and new bone formation was observed. The experimental group showed deposit of acellular extrinsic fiber cementum (AEFC) in a lamellae-like feature with inserted Sharpey's fibers, formation of cellular mixed stratified cementum (CMSC) with the presence of cementocytes, and newly formed bone close to the cementum-enamel junction. Cementoblast cells adjacent to new cementum expressed CAP, CEMP1, IBSP, and OCN. These studies show that CEMP1-p1 promotes the formation of AEFC, CMSC, new PDL with Sharpey's fibers inserted in cementum and bone, thus providing strong evidence that the synthetic peptide CEMP1-p1 promotes periodontal regeneration in a rat fenestration model.

Silver-sepiolite (Ag-Sep) hybrid reinforced active gelatin/date waste extract (DSWE) blend composite films for food packaging application

In this study, date syrup waste extract (DSWE) (15 wt%) and different content of silver doped sepiolite hybrid (Ag-Sep, 0.25–3 wt%) were incorporated into gelatin matrix to develop a series of active composite packaging films. Incorporating 2 wt% of Ag-Sep increased the modulus of blend film by 98% compared to unmodified gelatin/DSWE blend film. The active gelatin composite film exhibited superior active compounds migration to aqueous food simulants. Besides, Ag-Sep provided a tortuous pathway to the composite film, resulting in high 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical inhibition efficiency (91%) and slow-release kinetics of active compounds to the food simulant. The Ag-Sep hybrid was improved the antimicrobial property of the gelatin/DSWE blend film against both gram-negative and gram-positive microbes. Thus, this study demonstrated that the Ag-Sep hybrid exhibits significant properties in the active gelatin composite films, implying that this hybrid could be an effective additive for various active packaging films.

Preparation and Characterization of Gelatin-Based Films Cross-Linked by Two Essential Oils at Different Concentrations and Plasticized with Glycerol

Gelatin cross-linking has recently been discovered to be a very appealing method of producing gelatin-based films. The current research looks at various commercial gelatin (type B) films to improve their physical qualities. Bunium alpinum and bunium incrassatum essential oils (EOs) in two quantities (5% and 25%) were added to the films, which showed substantial biological activity (antibacterial, antioxidant, antihemolytic, and anti-inflammatory). According to electronic scanning microscopy, the basic gelatin matrix had changed and there were multiple dense spots on the cross-linked films. The particles appear to be more bonded in an isotropic form. Infrared spectroscopy cannot provide substantial accuracy on the new characteristics and chemical interactions formed due to the complex system of both gelatin and EOs. According to the UV transmission test results, adding EOs to gelatin films improves the barrier properties against UV rays and prevents UV light transmission. Finally, the swelling water test revealed that included EOs in the film composition reduce the film's swelling.

Prospective study examining the use of thrombin–gelatin matrix (Floseal) to prevent post dental extraction haemorrhage in patients with inherited bleeding disorders

The bleeding risk in individuals with inherited bleeding disorders (IBDs) during exodontia is traditionally managed with perioperative coagulation factors and/or desmopressin, in conjunction with systemic and topical perioperative tranexamic acid and meticulous primary closure. Factor replacement is costly, requires specialist input, and carries a risk of developing factor VIII (FVIII) inhibitors. This prospective study was performed to determine whether the use of a standardized Floseal and anti-fibrinolytic protocol could reduce postoperative bleeding in patients with IBDs undergoing dental extraction, as compared to factor replacement. All patients >18 years old attending Queensland Haemophilia Centre between November 2014 and July 2019 who required dental extractions were referred to the Oral and Maxillofacial Unit. Patients were consented for intraoperative Floseal administration instead of factor replacement. All other operative measures remained the same. The bleed rate was assessed against a historical control cohort. There were 34 extraction events in 32 patients. Four of the patients reported postoperative bleeding requiring factor supplementation or desmopressin; the bleeding rate was 11.8%. While not statistically significant, this was a reduction in the bleed rate compared to the traditional protocol (P = 0.35). Third molar extractions were 10.33 times more likely to cause postoperative bleeding (P = 0.018). The Floseal protocol was equipotent to the traditional perioperative factor replacement protocol. Floseal use is more economical, eliminates the risk of peri-procedural FVIII inhibitor development, and provides a haemostatic option for patients with very rare factor deficiencies, pre-existing clotting factor inhibitors, and those with anaphylaxis to clotting concentrates.

Novel emulsion film based on gelatin/polydextrose/camellia oil incorporated with Lactobacillus pentosus: Physical, structural, and antibacterial properties

Edible films incorporated with probiotics and prebiotics have been presented an efficient strategy for food preservation. In this study, novel bioactive emulsion films fabricated from gelatin (GEL), camellia oil (CO, 50% and 100%, based on GEL), polydextrose (PD, 10% and 20%, based on GEL), and L. pentosus (109 CFU/mL) were evaluated by SEM, FTIR, DSC, mechanical, barrier, antioxidant and antibacterial properties analyses. Results suggested that the viability of L. pentosus was not affected by the addition of 50% CO, while significantly decreased by 100% CO (P < 0.05). The CO, PD and their combination significantly decreased the tensile strength and enhanced the elongation at break (P < 0.05). The water vapor barrier and UV-resistance properties of the films were improved with the incorporation of CO (P < 0.05). The FTIR and SEM suggested that CO was successfully distributed in GEL-based films through emulsification. The L. pentosus was also observed to be embedded in the GEL matrix by SEM. The GEL/CO50/PD20 film exhibited the highest DPPH free radical scavenging activity (46.18 ± 1.36%) and the largest inhibition zones against S. aureus (33.84 ± 0.31 mm) and E. coli (34.25 ± 0.69 mm). In conclusion, the novel probiotic emulsion film could provide a new method to develop active food packaging.

Anisotropic diffusion of Fe ions in Fricke-XO-Pluronic F-127 and Fricke-XO-gelatine 3D radiotherapy dosimeters

A new radiochromic dosimeter was examined with Raman spectroscopy and an optical approach for assessment of 3D dose distribution integrity. The acronym of the dosimeter is Fricke-XO-Pluronic F-127, where XO denotes xylenol orange; Pluronic F-127 is a copolymer matrix of poly(ethylene oxide)-block-poly(propylene oxide)-block-poly(ethylene oxide), and the dosimeter contains the components of a Fricke dosimetric solution. Two dosimeter samples in cuvettes were partially irradiated such that a radiation dose was absorbed at the bottom of the cuvettes. After irradiation, one sample was stored upside down such that the irradiated part was at the top and another one was stored with the irradiated part at the bottom. Two diffusion coefficients of ferric ion complexes with XO ([XO-Fe]+3) were calculated. They were compared with those for similar dosimeter, however with gelatine matrix instead of Pluronic F-127. The results obtained indicate an impact of the gravitational force on the diffusion of [XO-Fe]+3 ions over time after irradiation and thus a possibility of severely undermining the integrity of a dose distribution in irradiated dosimeter. The conclusions drawn suggest the necessity of examination of different 3D Fricke dosimeter compositions for anisotropic diffusion of ferric ions.

Characteristic Comparison of an Intraoral Thin Film Containing Astaxanthin Nanoemulsion Using Sodium Alginate and Gelatin Polymers

The present study was conducted to compare the characteristics of a thin film containing an astaxanthin-loaded nanoemulsion (TFANE) using two kinds of natural polymers, namely sodium alginate and gelatin. An astaxanthin nanoemulsion was prepared by using the self-nanoemulsifying method, followed by incorporation into a polymer matrix system by the solvent casting method to form TFANE. A characteristic comparison between the sodium alginate and gelatin matrix systems was carried out by comparing the physical and mechanical film properties. At the end of the study, in vitro dissolution tests were also assessed. An intraoral film with good physical and mechanical properties containing an astaxanthin-loaded nanoemulsion was developed successfully using a natural polymer matrix system. The film, made from a gelatin matrix system containing an astaxanthin nanoemulsion, was more flexible and harder than films made from a sodium alginate matrix system, where all of the films have ideal characteristics for intraoral delivery. The dissolution test results showed that, with both sodium alginate and gelatin, more than 90% of the drug was released at 15 minutes. Gelatin as a natural polymer appears to be promising for the preparation of an intraoral thin film delivery system.

Evaluating the addition of xylooligosaccharides into alginate-gelatin hydrogels

Xylooligosaccharides (XOS) are emerging prebiotic that may improve structural features of biopolymer blends. The investigation around the conformation of XOS into the matrix of alginate and gelatin clarifies the potential applications of this formulation in the food industry as texture modifiers or encapsulation systems. Structural properties verified by flow behavior, SEM, XRD, and FT-IR demonstrated that the add up to 3% XOS into the alginate-gelatin blend formed a cohesive matrix, with smaller pores and crystalline structure, confirming the potential of xylooligosaccharides hydrogels for the development of functional and synbiotic foods.

Self-healable and flexible supramolecular gelatin/MoS2 hydrogels with molecular recognition properties

Two-dimensional MoS2 is emerging as a unique platform for a wide range of biomedical applications including extracellular matrix mimics, drug delivery systems and antimicrobial agents. However, low processability and nonspecific interactions at biointerfaces are serious challenges that hamper the biomedical applications of this nanomaterial. Herein, we show how specific interactions between MoS2 and a gelatin matrix results in a biomimetic hydrogel with the self-healing and molecular recognition properties. β-Cyclodextrin was conjugated to the surface of freshly exfoliated MoS2 through a one pot nucleophilic substitution reaction and the obtained cyclodextrin-functionalized MoS2 was used to construct an injectable, self-healable and flexible supramolecular hydrogel upon host-guest interactions with adamantane-modified gelatin matrix. Incorporation of almost 1 wt% of CDMoS2 into gelatin matrix with 1cm2 cross-section resulted in a hydrogel that was able to tolerate one hundred grams. Also, storage modulus (G′), loss modulus (G″) of the obtained hydrogel was 10 and 25 times higher than that for the neat gelatin, respectively.Due to its self-healing, molecular recognition and mechanical properties as well as its flexibility, injectability, and processability, MoS2gel is a promising candidate for a wide range of future biomedical applications including extracellular matrix mimics and tissue engineering.