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1.
J Sci Food Agric ; 2024 Apr 04.
Artigo em Inglês | MEDLINE | ID: mdl-38572795

RESUMO

BACKGROUND: The present study aimed to investigate the effects of tremella polysaccharides on the gel properties and antioxidant activity of yak skin gelatin with a view to improving the quality of collagen jellies. The preparation of composite gels were performed by yak skin gelatin (66.7 mg mL-1) and tremella polysaccharides with different concentrations (0, 2, 4, 6, 8 mg mL-1), and finally the collagen jelly was prepared by composite gel (yak skin gelatin: 66.7 mg mL-1; tremella polysaccharides:6 mg mL-1) with the best performance. RESULTS: Tremella polysaccharides not only improved the hardness, springiness, gel strength, water holding capacity and melting temperature of yak skin gelatin, but also enhanced the composite gel's scavenging activity against ABTS radicals, DPPH radicals, O2 and OH radicals. The filling of tremella polysaccharides into the gelatin network increased the number of crosslinking sites inside the gel, which resulted in the gel network structure becoming dense and orderly. The gel particles became finer and more uniform, and the thermal stability was improved. Furthermore, the sensory score of commercially available gelatin jelly decreased more rapidly during storage compared to the composite gel jelly. CONCLUSION: The gel properties and antioxidant activity of yak skin gelatin were improved by adding tremella polysaccharides, and then the quality and storage properties of the jelly were improved, which also provided technical reference for the development of functional gel food. © 2024 Society of Chemical Industry.

2.
Macromol Biosci ; : e2400036, 2024 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-38621113

RESUMO

Dental implant surgery is a procedure that replaces damaged or missing teeth with an artificial implant. During this procedure, guided bone regeneration (GBR) membranes were commonly used to inhibit the migration of epithelium and guided bone regeneration at the surgical sites. Due to its biodegradability, good biocompatibility, and unique biological properties, gelatin (GT) was considered a suitable candidate for guiding periodontal tissue regeneration. However, GT-based membranes come with limitations, such as poor mechanical strength and mismatched degradation rates. To confront this challenge, we fabricated a series of GT/poly(4-hydroxybutyrate) (P4HB) composite membranes through electrospinning technology. The morphology, composition, wetting properties, mechanical properties, biocompatibility, and in vivo biodegradability of the as-prepared composite membranes were carefully characterized. The results demonstrated that all the membranes present excellent biocompatibility. Moreover, the in vivo degradation rate of the membranes can be manipulated by changing the ratio of GT and P4HB. The results indicated that the optimized GT/P4HB membranes with a high P4HB content (75%) may be suitable for periodontal tissue engineering because of their good mechanical properties and biodegradation rate compatible with tissue growth. This article is protected by copyright. All rights reserved.

3.
Int J Artif Organs ; : 3913988241244661, 2024 Apr 16.
Artigo em Inglês | MEDLINE | ID: mdl-38624101

RESUMO

The challenges in achieving optimal outcomes for wound healing have persisted for decades, prompting ongoing exploration of interventions and management strategies. This study focuses on assessing the potential benefits of implementing a nano-gelatin scaffold for wound healing. Using a rat skin defect model, full-thickness incisional wounds were created on each side of the thoracic-lumbar regions after anesthesia. The wounds were left un-sutured, with one side covered by a gelatin nano-fibrous membrane and the other left uncovered. Wound size changes were measured on days 1, 4, 7, and 14, and on day 14, rats were sacrificed for tissue sample excision, examined with hematoxylin and eosin, and Masson's trichrome stain. Statistical comparisons were performed. The gelatin nanofibers exhibited a smooth surface with a fiber diameter of 260 ± 40 nm and porous structures with proper interconnectivity. Throughout the 14-day experimental period, significant differences in the percentage of wound closure were observed between the groups. Histological scores were higher in the experiment group, indicating less inflammation but dense and well-aligned collagen fiber formation. A preliminary clinical trial on diabetic ulcers also demonstrated promising results. This study highlights the potential of the nano-collagen fibrous membrane to reduce inflammatory infiltration and enhance fibroblast differentiation into myofibroblasts during the early stages of cutaneous wound healing. The nano-fibrous collagen membrane emerges as a promising candidate for promoting wound healing, with considerable potential for future therapeutic applications.

4.
Polymers (Basel) ; 16(7)2024 Mar 25.
Artigo em Inglês | MEDLINE | ID: mdl-38611154

RESUMO

Fish gelatin (FG)-based wound dressings exhibit superior water absorption capacity, thermal stability, and gelation properties, which enhance the performance of these dressings. In this study, our objective was to investigate the conditions underlying the enzymatic hydrolysis of FG and subsequent cross-linking to prepare high-performance gels. A two-step enzymatic method of protease-catalyzed hydrolysis followed by glutamine transglutaminase (TGase)-catalyzed cross-linking was used to prepare novel high-performance fish gelatin derivatives with more stable dispersion characteristics than those of natural gelatin derivatives. Compared with conventional TGase cross-linked derivatives, the novel derivatives were characterized by an average pore size of 150 µm and increased water solubility (423.06% to 915.55%), water retention (by 3.6-fold to 43.89%), thermal stability (from 313 °C to 323 °C), and water vapor transmission rate, which reached 486.72 g·m-2·24 h-1. In addition, loading glucose oxidase onto the fish gelatin derivatives increased their antibacterial efficacy to >99% against Escherichia coli and Staphylococcus aureus.

5.
Polymers (Basel) ; 16(7)2024 Apr 05.
Artigo em Inglês | MEDLINE | ID: mdl-38611257

RESUMO

Gelatin-based hydrogels with excellent mechanical properties and conductivities are desirable, but their fabrication is challenging. In this work, an innovative approach for the preparation of gelatin-based conductive hydrogels is presented that improves the mechanical and conductive properties of hydrogels by integrating Z-Gln-Gly into gelatin polymers via enzymatic crosslinking. In these hydrogels (Gel-TG-ZQG), dynamic π-π stacking interactions are created by the introduction of carbobenzoxy groups, which can increase the elasticity and toughness of the hydrogel and improve the conductivity sensitivity by forming effective electronic pathways. Moreover, the mechanical properties and conductivity of the obtained hydrogel can be controlled by tuning the molar ratio of Z-Gln-Gly to the primary amino groups in gelatin. The hydrogel with the optimal mechanical properties (Gel-TG-ZQG (0.25)) exhibits a high storage modulus, compressive strength, tensile strength, and elongation at break of 7.8 MPa at 10 °C, 0.15 MPa at 80% strain, 0.343 MPa, and 218.30%, respectively. The obtained Gel-TG-ZQG (0.25) strain sensor exhibits a short response/recovery time (260.37 ms/130.02 ms) and high sensitivity (0.138 kPa-1) in small pressure ranges (0-2.3 kPa). The Gel-TG-ZQG (0.25) hydrogel-based sensors can detect full-range human activities, such as swallowing, fist clenching, knee bending and finger pressing, with high sensitivity and stability, yielding highly reproducible and repeatable sensor responses. Additionally, the Gel-TG-ZQG hydrogels are noncytotoxic. All the results demonstrate that the Gel-TG-ZQG hydrogel has potential as a biosensor for wearable devices and health-monitoring systems.

6.
Polymers (Basel) ; 16(7)2024 Apr 07.
Artigo em Inglês | MEDLINE | ID: mdl-38611267

RESUMO

The aim of this work was to develop edible films derived from gelatin and beef broth and to analyze the physical properties of the output products. The presented research is important from the point of view of searching for food packaging solutions that may replace traditionally used plastic packaging. This study's conceptual framework is in line with the trend of sustainable development and zero waste. This study was conducted to develop a recipe for edible films derived from beef gelatin with gelatin concentrations at 4%, 8%, and 12% enriched with additions of beef broth in amounts of 25, 50, 75, and 100%. Selected physical properties of the output edible films were examined in terms of thickness, swelling in water, opacity, water content, water solubility, structure, and mechanical properties. The conducted research made it plausible to conclude that the addition of broth has a positive effect on the extensibility of the edible films and the other physical properties under consideration, especially on decreasing the film thickness, which was found to vary between 50.2 and 191.6 µm. When gelatin and broth were added at low concentrations, the tensile strength of the films increased, and subsequently decreased; however, an opposite effect was observed for elongation at break. The increased broth concentration caused the film opacity to increase from 0.39 to 4.54 A/mm and from 0.18 to 1.04 A/mm with gelatin concentrations of 4% and 12%, respectively. The water solubility of the gelatin films decreased as a result of the broth addition. However, it was noticed that increasing the content of broth caused the water solubility to increase in the tested films. The mere presence of broth in the gelatin films changed the microstructure of the films and also made them thinner.

7.
Foods ; 13(7)2024 Apr 03.
Artigo em Inglês | MEDLINE | ID: mdl-38611406

RESUMO

In this work, a gelatin/chia mucilage (GN/CM) composite coating material doped with Lactococcus lactis (LS) was developed for strawberry preservation applications. The results of the scanning electron microscope and Fourier transform infrared spectroscopy stated that the enhanced molecular interaction between the CM and GN matrix strengthened the density and compactness of the GN film. Antifungal results indicated that the addition of LS significantly (p < 0.05) improved the ability of the GN coating to inhibit the growth of Botrytis cinerea (inhibition percentage = 62.0 ± 4.6%). Adding CM significantly (p < 0.05) decreased the water vapour permeability and oxygen permeability of the GN coating by 32.7 ± 4.0% and 15.76 ± 1.89%, respectively. In addition, the incorporated CM also significantly (p < 0.05) improved the LS viability and elongation at break of the film by 13.11 ± 2.05% and 42.58 ± 1.21%, respectively. The GN/CM/LS composite coating material also exhibited an excellent washability. The results of this study indicated that the developed GN/CM/LS coating could be used as a novel active material for strawberry preservation.

8.
ACS Appl Bio Mater ; 2024 Apr 11.
Artigo em Inglês | MEDLINE | ID: mdl-38602318

RESUMO

Three-dimensional (3D) bioprinting of hydrogels with a wide spectrum of compositions has been widely investigated. Despite such efforts, a comprehensive understanding of the correlation among the process science, buildability, and biophysical properties of the hydrogels for a targeted clinical application has not been developed in the scientific community. In particular, the quantitative analysis across the entire developmental path for 3D extrusion bioprinting of such scaffolds is not widely reported. In the present work, we addressed this gap by using widely investigated biomaterials, such as gelatin methacryloyl (GelMA), as a model system. Using extensive experiments and quantitative analysis, we analyzed how the individual components of methacrylated carboxymethyl cellulose (mCMC), needle-shaped nanohydroxyapatite (nHAp), and poly(ethylene glycol)diacrylate (PEGDA) with GelMA as baseline matrix of the multifunctional bioink can influence the biophysical properties, printability, and cellular functionality. The complex interplay among the biomaterial ink formulations, viscoelastic properties, and printability toward the large structure buildability (structurally stable cube scaffolds with 15 mm edge) has been explored. Intriguingly, the incorporation of PEGDA into the GelMA/mCMC matrix offered improved compressive modulus (∼40-fold), reduced swelling ratio (∼2-fold), and degradation rates (∼30-fold) compared to pristine GelMA. The correlation among microstructural pore architecture, biophysical properties, and cytocompatibility is also established for the biomaterial inks. These photopolymerizable bio(material)inks served as the platform for the growth and development of bone and cartilage matrix when human mesenchymal stem cells (hMSCs) are either seeded on two-dimensional (2D) substrates or encapsulated on 3D scaffolds. Taken together, this present study unequivocally establishes a significant step forward in the development of a broad spectrum of shape-fidelity compliant bioink for the 3D bioprinting of multifunctional scaffolds and emphasizes the need for invoking more quantitative analysis in establishing process-microstructure-property correlation.

9.
Nanomaterials (Basel) ; 14(7)2024 Mar 23.
Artigo em Inglês | MEDLINE | ID: mdl-38607098

RESUMO

Tympanic membrane (TM) perforations, primarily induced by middle ear infections, the introduction of foreign objects into the ear, and acoustic trauma, lead to hearing abnormalities and ear infections. We describe the design and fabrication of a novel composite patch containing photocrosslinkable gelatin methacryloyl (GelMA) and keratin methacryloyl (KerMA) hydrogels. GelMA-KerMA patches containing conical microneedles in their design were developed using the digital light processing (DLP) 3D printing approach. Following this, the patches were biofunctionalized by applying a coaxial coating with PVA nanoparticles loaded with gentamicin (GEN) and fibroblast growth factor (FGF-2) with the Electrohydrodynamic Atomization (EHDA) method. The developed nanoparticle-coated 3D-printed patches were evaluated in terms of their chemical, morphological, mechanical, swelling, and degradation behavior. In addition, the GEN and FGF-2 release profiles, antimicrobial properties, and biocompatibility of the patches were examined in vitro. The morphological assessment verified the successful fabrication and nanoparticle coating of the 3D-printed GelMA-KerMA patches. The outcomes of antibacterial tests demonstrated that GEN@PVA/GelMA-KerMA patches exhibited substantial antibacterial efficacy against Staphylococcus aureus, Pseudomonas aeruginosa, and Escherichia coli. Furthermore, cell culture studies revealed that GelMA-KerMA patches were biocompatible with human adipose-derived mesenchymal stem cells (hADMSC) and supported cell attachment and proliferation without any cytotoxicity. These findings indicated that biofunctional 3D-printed GelMA-KerMA patches have the potential to be a promising therapeutic approach for addressing TM perforations.

10.
Front Nutr ; 11: 1343394, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38571750

RESUMO

In this work, the effect of the addition of γ-polyglutamic acid (γ-PGA) on the rheology, physicochemical properties, and microstructure of fish gelatin (FG) emulsion gel was investigated. Samples of the emulsion gel were evaluated for rheological behavior and stability prior to gelation. The mechanical properties and water-holding capacity (WHC) of the emulsion were determined after gelation. The microstructure of the emulsion gel was further examined using confocal laser scanning microscopy (CLSM). The results indicated a gradual increase in the apparent viscosity and gelation temperature of the emulsion at a higher concentration of γ-PGA. Additionally, frequency scan results revealed that on the addition of γ-PGA, FG emulsion exhibited a stronger structure. The emulsion containing 0.1% γ-PGA exhibited higher stability than that of the control samples. The WHC and gel strength of the emulsion gel increased on increasing the γ-PGA concentration. CLSM images showed that the addition of γ-PGA modified the structure of the emulsion gel, and the droplets containing 0.1% γ-PGA were evenly distributed. Moreover, γ-PGA could regulate the droplet size of the FG emulsion and its size distribution. These findings suggest that the viscoelasticity and structure of FG emulsion gels could be regulated by adjusting the γ-PGA concentration. The γ-PGA-modified FG emulsion gel also exhibited improved rheology and physicochemical properties. The results showed that γ-PGA-modified FG emulsion gel may find potential applications in food, medicine, cosmetics, and other industries.

11.
Regen Biomater ; 11: rbae022, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38567105

RESUMO

Physiological repair of large-sized bone defects requires instructive scaffolds with appropriate mechanical properties, biocompatibility, biodegradability, vasculogenic ability and osteo-inductivity. The objective of this study was to fabricate in situ injectable hydrogels using platelet-rich plasma (PRP)-loaded gelatin methacrylate (GM) and employ them for the regeneration of large-sized bone defects. We performed various biological assays as well as assessed the mechanical properties of GM@PRP hydrogels alongside evaluating the release kinetics of growth factors (GFs) from hydrogels. The GM@PRP hydrogels manifested sufficient mechanical properties to support the filling of the tissue defects. For biofunction assay, the GM@PRP hydrogels significantly improved cell migration and angiogenesis. Especially, transcriptome RNA sequencing of human umbilical vein endothelial cells and bone marrow-derived stem cells were performed to delineate vascularization and biomineralization abilities of GM@PRP hydrogels. The GM@PRP hydrogels were subcutaneously implanted in rats for up to 4 weeks for preliminary biocompatibility followed by their transplantation into a tibial defect model for up to 8 weeks in rats. Tibial defects treated with GM@PRP hydrogels manifested significant bone regeneration as well as angiogenesis, biomineralization, and collagen deposition. Based on the biocompatibility and biological function of GM@PRP hydrogels, a new strategy is provided for the regenerative repair of large-size bone defects.

12.
J Biosci Bioeng ; 2024 Apr 02.
Artigo em Inglês | MEDLINE | ID: mdl-38570220

RESUMO

The choice of sterilization method for hydrogels used for cell culture influences the ease of preparing the gel. We prepared interpenetrating gelatin/calcium alginate hydrogels containing 1% (w/v) alginate and 1-16% (w/v) gelatin by molding with the mixture of gelatin/sodium alginate solution, followed by the addition of calcium ions by incubation in calcium chloride solution. It is the simplest method to prepare autoclavable gelatin/sodium hydrogel. We measured various properties of the hydrogels including volume, Young's modulus in the compression test, storage modulus, and loss modulus in the dynamic viscoelasticity measurement. The gelatin/alginate hydrogel can be easily fabricated into any shape by this method. After autoclave treatment, the hydrogel was shrunk to smaller than the original shape in similar figures. The shape of the gelatin/alginate hydrogel can be designed into any shape with the reduction ratio of the volume. Human osteosarcoma (HOS) cells adhered to the gelatin/alginate hydrogel and then proliferated. Gelatin/calcium alginate hydrogels with a high concentration are considered to be autoclavable culture substrates because of their low deformation and gelatin elution rate after autoclaving and the high amount of cells attached to the hydrogels.

13.
Food Chem ; 449: 139214, 2024 Apr 02.
Artigo em Inglês | MEDLINE | ID: mdl-38581790

RESUMO

This study investigated the effects of ultrasound-assisted phosphorylation on gelling properties of fish gelatin (FG). Ultrasound-assisted phosphorylation (UP) for 60, 90, and 120 min resulted in >6.54% increase of phosphorylation degree and decreased zeta potential of FG. Atomic force microscopy revealed that UP-FGs showed larger aggregates than P-FGs (normal phosphorylation FGs). Low frequent-NMR and microstructure analysis revealed that phosphorylation enhanced water-binding capability of FG and improved the gel networks. However, UP60 had the highest gel strength (340 g), gelling (17.96 °C) and melting (26.54 °C) temperature while UP90 and UP120 showed slightly lower of them. FTIR analysis indicated thatß-sheet and triple helix content increased but random coil content decreased in phosphorylated FGs. Mass spectrometry demonstrated phosphate groups mainly bound to serine, threonine and tyrosine residues of FG and UP-FG exhibited more phosphorylation sites. The study showed that mild phosphorylation (UP60) could be applied to improve FG gel properties.

14.
Food Chem X ; 22: 101327, 2024 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-38590633

RESUMO

To investigate the effect of gelatin peptide on the inhibition of quality deterioration in stored pudding, gelatin peptide with antioxidant properties was added to pudding products. For this purpose, a pudding recipe containing gelatin peptides was created. The gelatin peptides were characterized based on their antioxidant activity and protein structure. It was found that gelatin peptides had better antioxidant properties, lower thermal stability and crystallinity, higher hydrophobic amino acid content, and greater surface hydrogen bond exposure than commercially available peptides. Properties such as the pH, colony growth, and sensory characteristics of the pudding were characterized at 4 °C and 25 °C. The results showed that the addition of 0.5-1.0 % gelatin peptide to pudding was capable of significantly (P< 0.05) slowing down the decline in pH and sensory scores of the pudding and significantly inhibiting colony growth. It could prolong its storage life by five days at 4 °C and three days at 25 °C.

15.
Carbohydr Polym ; 335: 121920, 2024 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-38616070

RESUMO

Natural polymer-based hydrogels have been wildly used in electronic skin, health monitoring and human motion sensing. However, the construction of hydrogel with excellent mechanical strength and electrical conductivity totally using natural polymers still faces many challenges. In this paper, gelatin and oxidized sodium carboxymethylcellulose were used to synthesize a double-network hydrogel through the dynamic Schiff base bonds. Then, the mechanical strength of the hydrogel was further enhanced by immersing it in an ammonium sulfate solution based on the Hofmeister effect between gelatin and salt. Finally, the gelatin/oxidized sodium carboxymethylcellulose hydrogel exhibited high tensile properties (614 %), tensile fracture strength (2.6 MPa), excellent compressive fracture strength (64 MPa), and compressive toughness (4.28 MJ/m3). Also, the electrical conductivity reached 3.94 S/m. The hydrogel after salt soaked was fabricated as strain sensors, which could accurately monitor the movement of many joints in the human body, such as fingers, wrists, elbows, neck, and throat. Therefore, the designed hydrogel fully originated from natural polymers and has great application potential in motion detection and information recording.

16.
J Biophotonics ; : e202300536, 2024 Apr 14.
Artigo em Inglês | MEDLINE | ID: mdl-38616109

RESUMO

Information about tissue oxygen saturation (StO2) and other related important physiological parameters can be extracted from diffuse reflectance spectra measured through non-contact imaging. Three analytical optical reflectance models for homogeneous, semi-infinite, tissue have been proposed (Modified Beer-Lambert, Jacques 1999, Yudovsky 2009) but these have not been directly compared for tissue parameter extraction purposes. We compare these analytical models using Monte Carlo (MC) simulated diffuse reflectance spectra and controlled gelatin-based phantoms with measured diffuse reflectance spectra and known ground truth composition parameters. The Yudovsky model performed best against MC simulations and measured spectra of tissue phantoms in terms of goodness of fit and parameter extraction accuracy followed closely by Jacques' model. In this study, Yudovsky's model appeared most robust; however, our results demonstrated that both Yudovsky and Jacques models are suitable for modeling tissue that can be approximated as a single, homogeneous, semi-infinite slab.

17.
J Sci Food Agric ; 2024 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-38619109

RESUMO

BACKGROUND: Conventional petroleum-based packaging films cause severe environmental problems. In this work bio-edible film as a safe to replace petroleum-based polymers was introduced. A food application for edible sachets and a composite edible film (EF) from marine algae, Gracilaria fisheri (GF) extract were proposed. RESULTS: Carbohydrates were the most prevalent component in fresh GF fronds. Under neutral conditions at 90 °C for 40 min, the extract's structure was determined by FTIR to be a carrageenan-like polysaccharide. Glycerol was the best plasticizer for EF formation since it had the highest tensile strength (TS). The integration of gelatin into the algal composite film with gelatin (CFG) was validated by significant. The best casting temperatures for 2 h were 70 and 100 °C among the four tested temperatures (25, 60, 70, and 100 °C). Temperatures did not result in significant (p ≤ 0.05) differences in any character (color values, TS, water vapor permeability, oxygen transmission, thickness, and water activity), except elongation at break. Visually, the CFG had a slightly yellow appearance. The best-to-worst order of film stability in the three tested solvents was oil, distilled water (DW), and ethanol. Its stability in ethanol (0-100%), temperature of DW (30-100 °C), and pH (3-7 in DW) demonstrated inverse variations with the concentration or different conditions, except for pH 8-10 in DW. All treatments were significantly (p ≤ 0.05) different. CONCLUSION: The novel material made from polysaccharides from algae, G. fisheri, was used to improve EF. The edible sachet application was plausible from the EF. This article is protected by copyright. All rights reserved.

18.
Artigo em Inglês | MEDLINE | ID: mdl-38627235

RESUMO

A novel double-network conductive hydrogel based on lithium acetate/gelatin/polyacrylamide (PAAM) was synthesized by heating-cooling and subsequent γ-ray radiation-induced polymerization and cross-linking. Owing to the hydrogen bonding interaction between lithium acetate, physical cross-linked gelatin, and chemical cross-linked PAAM, the resultant hydrogel exhibited high tensile strength (1260 kPa), high ionic conductivity (35.2 mS cm-1), notch-insensitivity (tensile strength 415 kPa, elongation at break 872% with transverse notch), and extensive strain monitoring range (0.15-800%) under optimum conditions. The lithium acetate/gelatin/polyacrylamide hydrogel strain sensor attached to the skin can sensitively monitor the subtle movements of the human body. The strain sensor based on the resultant hydrogel with transverse notch can still work for 1200 cycles, due to that the covalent-cross-linked PAAm chain bridges the cracks and stabilizes the deformation, while the physical-cross-linked gelatin was unzipped to make the blunting of notch. The conductive hydrogel with high-sensitivity and high stability is expected to be used as materials for the preparation of flexible strain sensors in the future.

19.
J Dent Sci ; 19(2): 900-908, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38618111

RESUMO

Background/purpose: Porcine collagen is widely used in regenerative therapies to generate membranes for bone augmentation. However, porcine or bovine gelatin or collagen is often not appropriate for patients with creed and religious beliefs or for allergic reasons. In this study, we evaluated the potential of fish gelatin to generate membranes. Materials and methods: Fish gelatin and hydroxyapatite (HAp) were used at three different ratios (2:0, 2:1, 2:1.5, and 2:2) to prepare gelatin-hydroxyapatite (G-HAp) membranes via freeze-drying and heat-crosslinking. The surface morphology and cell attachment of G-HAp membranes were observed using scanning electron microscopy and confocal laser microscopy. G-HAp membrane was placed at the bottom of a well plate, and MC3T3-E1 cells were seeded on it. Cell viability and cytotoxicity were tested after 1 and 3 days of culture. Alkaline phosphatase (ALP) and alizarin red staining was performed at 10 and 21 days, respectively. Results: Viability of cells on G-HAp membrane with the gelatin:HAp ratio of 2:1.5 was significantly higher than that on membranes with other gelatin:HAp ratios. ALP and alizarin red staining showed that ALP-positive areas and calcium deposition were the highest on G-HAp membrane with the gelatin:HAp ratio of 2:1. These membranes showed negligible cytotoxicity. Conclusion: Fish-derived G-HAp membranes have the potential to promote osteogenic differentiation of MC3T3-E1 cells with negligible cytotoxicity.

20.
Bio Protoc ; 14(7): e4970, 2024 Apr 05.
Artigo em Inglês | MEDLINE | ID: mdl-38618176

RESUMO

Periodontal disease is characterized by the destruction of the hard and soft tissues comprising the periodontium. This destruction translates to a degradation of the extracellular matrices (ECM), mediated by bacterial proteases, host-derived matrix metalloproteinases (MMPs), and other proteases released by host tissues and immune cells. Bacterial pathogens interact with host tissue, triggering adverse cellular functions, including a heightened immune response, tissue destruction, and tissue migration. The oral spirochete Treponema denticola is highly associated with periodontal disease. Dentilisin, a T. denticola outer membrane protein complex, contributes to the chronic activation of pro-MMP-2 in periodontal ligament (PDL) cells and triggers increased expression levels of activators and effectors of active MMP-2 in PDL cells. Despite these advances, no mechanism for dentilisin-induced MMP-2 activation or PDL cytopathic behaviors leading to disease is known. Here, we describe a method for purification of large amounts of the dentilisin protease complex from T. denticola and demonstrate its ability to activate MMP-2, a key regulator of periodontal tissue homeostasis. The T. denticola dentilisin and MMP-2 activation model presented here may provide new insights into the dentilisin protein and identify potential therapeutic targets for further research. Key features • This protocol builds upon a method described by Cunningham et al. [1] for selective release of Treponema outer membrane proteins. • We adapted the protocol for the purification of biologically active, detergent-stable outer membrane protein complexes from large batch cultures of T. denticola. • The protocol involves large-scale preparative electrophoresis using a Model 491 Prep Cell. • We then use gelatin zymography to demonstrate the activity of the purified dentilisin complex by its ability to activate matrix metalloproteinase 2 (MMP-2).

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