Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 13.217
Filtrar
1.
Food Chem ; 393: 133348, 2022 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-35661603

RESUMO

In this study, fish skin gelatin (FG) obtained from sea bream (Sparus aurata) was evaluated as an alternative to mammalian gelatin. Improvement in rheological properties of FG was attempted with addition of grape pomace (GP), pomegranate peel (PP), and green tea (GT) extracts, all of which are agricultural wastes rich in phenolic components. These additives were added at ratios of 20%, 13.3%, 10%, and 6.7% to determine the best formulation. Melting and gelling temperatures, kgel, gel strength, and tmodel values of samples were measured. 20% GP added fish gelatin (OG) had optimum rheological properties. Melting temperatures of BG, OG, and FG were 31.64 ± 0.28, 33.80 ± 0.54, 25.78 ± 0.24 °C, respectively. The addition of GP caused a 14% increase in Tg by increasing the intermolecular interactions of FG. GP is important in that it provides functional properties and structural improvement of FG, making it an alternative to BG and facilitating its use in confectionery industry.


Assuntos
Gelatina , Dourada , Animais , Coloides , Gelatina/química , Géis/química , Mamíferos , Extratos Vegetais , Reologia
2.
ACS Appl Mater Interfaces ; 14(24): 27575-27588, 2022 Jun 22.
Artigo em Inglês | MEDLINE | ID: mdl-35674114

RESUMO

Bioprinting is a biofabrication technology which allows efficient and large-scale manufacture of 3D cell culture systems. However, the available biomaterials for bioinks used in bioprinting are limited by their printability and biological functionality. Fabricated constructs are often homogeneous and have limited complexity in terms of current 3D cell culture systems comprising multiple cell types. Inspired by the phenomenon that hydrogels can exchange liquids under the infiltration action, infiltration-induced suspension bioprinting (IISBP), a novel printing technique based on a hyaluronic acid (HA) suspension system to modulate the properties of the printed scaffolds by infiltration action, was described in this study. HA served as a suspension system due to its shear-thinning and self-healing rheological properties, simplicity of preparation, reusability, and ease of adjustment to osmotic pressure. Changes in osmotic pressure were able to direct the swelling or shrinkage of 3D printed gelatin methacryloyl (GelMA)-based bioinks, enabling the regulation of physical properties such as fiber diameter, micromorphology, mechanical strength, and water absorption of 3D printed scaffolds. Human umbilical vein endothelial cells (HUVEC) were applied as a cell culture model and printed within cell-laden scaffolds at high resolution and cell viability with the IISBP technique. Herein, the IISBP technique had been realized as a reliable hydrogel-based bioprinting technique, which enabled facile modulation of 3D printed hydrogel scaffolds properties, being expected to meet the scaffolds requirements of a wide range of cell culture conditions to be utilized in bioprinting applications.


Assuntos
Bioimpressão , Bioimpressão/métodos , Gelatina , Células Endoteliais da Veia Umbilical Humana , Humanos , Hidrogéis , Metacrilatos , Impressão Tridimensional , Engenharia Tecidual/métodos , Tecidos Suporte
3.
Sci Rep ; 12(1): 10497, 2022 Jun 21.
Artigo em Inglês | MEDLINE | ID: mdl-35729201

RESUMO

The objective of this work was to develop biodegradable films by mixing gelatin/carboxymethylcellulose (FG/CMC) and gelatin/polyvinyl alcohol (FG/PVOH) and to evaluate the effect of adding these polymers on the properties of fish gelatin films. The films FG/CMC and FG/PVOH were produced in the proportions 90/10, 80/20 and 70/30 and characterized their physical, chemical and functional properties. The addition of CMC and PVOH improved the mechanical strength, barrier property and water solubility of gelatin films. FG/CMC films showed greater tensile strength and greater solubility than FG/PVOH. The maximum concentration of CMC promoted the highest mechanical resistance, while the highest PVOH content produced the film with the lowest solubility. The proposed mixing systems proved to be adequate to improve the properties of fish gelatin films, with potential for application in the packaging sector.


Assuntos
Gelatina , Álcool de Polivinil , Animais , Carboximetilcelulose Sódica/química , Peixes , Gelatina/química , Álcool de Polivinil/química , Resistência à Tração
4.
Biomed Pharmacother ; 152: 113275, 2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-35714510

RESUMO

There is no effective treatment for acute lung injury (ALI) at present. Some studies have reported the anti-inflammatory effect of Ejiao, but no study has addressed the underlying action mechanism. In this study, the CCK8 assay displayed Ejiao had a protective effect against LPS-elicited inflammatory lung epithelial Beas 2B cells (LILEB 2B cells). Beas 2B cells treated with LPS and Ejiao were challenged with NFκB inhibitor Bay11-7082 and ROS scavenger N-acetyl cysteine (NAC) alone and in combination. The results of qRT-PCR, Western blotting and fluorescence labeling experiments using Bay11-7082 and NAC demonstrated Ejiao could significantly decrease the expression of p-p65 and p-IκBα in NFκB signaling pathway and its downstream NLRP3, ASC, Caspase-1 and IL-1ß related to pyroptosis of LILEB 2B cells. Moreover, Ejiao reduced the production of mitochondrial ROS and reversed the change of mitochondrial membrane potential of LILEB 2B cells. Then, HE staining demonstrated Ejiao had a protective effect against the LPS-elicited ALI mouse model (LAMM). Ejiao also dramatically decreased the cell amount and the overall protein concentration of bronchoalveolar lavage fluid in LAMM. Immunohistochemical staining showed Ejiao remarkably reduced the expression of p-p65 and p-IκBα in NFκB signaling pathway and its downstream NLRP3, ASC, Caspase-1 and IL-1ß. The ELISA of IL-1ß revealed Ejiao could dose-dependably decrease the concentration of IL-1ß in lung tissues, serum and BALF of LAMM. Finally, fluorescence labeling demonstrated Ejiao significantly reduced the mitochondrial ROS generation in the lung tissue of LAMM. This finding may afford a novel strategy for the precaution and therapy of ALI.


Assuntos
Lesão Pulmonar Aguda , Pneumonia , Lesão Pulmonar Aguda/induzido quimicamente , Lesão Pulmonar Aguda/tratamento farmacológico , Lesão Pulmonar Aguda/metabolismo , Animais , Caspase 1/metabolismo , Gelatina , Inflamassomos/metabolismo , Lipopolissacarídeos/farmacologia , Camundongos , Inibidor de NF-kappaB alfa , NF-kappa B , Proteína 3 que Contém Domínio de Pirina da Família NLR/metabolismo , Pneumonia/induzido quimicamente , Pneumonia/tratamento farmacológico , Pneumonia/metabolismo , Espécies Reativas de Oxigênio/metabolismo
5.
Biomed Mater ; 17(5)2022 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-35654031

RESUMO

Three-dimensional bioprinting continues to advance as an attractive biofabrication technique to employ cell-laden hydrogel scaffolds in the creation of precise, user-defined constructs that can recapitulate the native tissue environment. Development and characterisation of new bioinks to expand the existing library helps to open avenues that can support a diversity of tissue engineering purposes and fulfil requirements in terms of both printability and supporting cell attachment. In this paper, we report the development and characterisation of agarose-gelatin (AG-Gel) hydrogel blends as a bioink for extrusion-based bioprinting. Four different AG-Gel hydrogel blend formulations with varying gelatin concentration were systematically characterised to evaluate suitability as a potential bioink for extrusion-based bioprinting. Additionally, autoclave and filter sterilisation methods were compared to evaluate their effect on bioink properties. Finally, the ability of the AG-Gel bioink to support cell viability and culture after printing was evaluated using SH-SY5Y cells encapsulated in bioprinted droplets of the AG-Gel. All bioink formulations demonstrate rheological, mechanical and swelling properties suitable for bioprinting and cell encapsulation. Autoclave sterilisation significantly affected the rheological properties of the AG-Gel bioinks compared to filter sterilisation. SH-SY5Y cells printed and differentiated into neuronal-like cells using the developed AG-Gel bioinks demonstrated high viability (>90%) after 23 d in culture. This study demonstrates the properties of AG-Gel as a printable and biocompatible material applicable for use as a bioink.


Assuntos
Bioimpressão , Neuroblastoma , Bioimpressão/métodos , Encapsulamento de Células , Gelatina , Humanos , Hidrogéis , Impressão Tridimensional , Sefarose , Engenharia Tecidual/métodos , Tecidos Suporte
6.
Carbohydr Polym ; 291: 119483, 2022 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-35698322

RESUMO

In this work, we studied the development of a biocomposite formulated with alginate and gelatin, crosslinked with genipin for application as support for ß-galactosidase immobilization. Also, the biocomposites with the immobilized enzyme were characterized by thermal analyses and SAXS (size, density, and interconnectivity of alginate rods) for a detailed analysis of the microstructure, as well as the thermal and operational stabilities of the enzyme. The structural modifications of the biocomposite determined by SAXS demonstrate that the addition of both genipin and enzyme produced a significant reduction in size and density of the Ca(II)-alginate rods. Immobilized ß-galactosidase could be stored for 175 days under refrigeration maintaining 80% of its initial activity. Moreover, 90% of its relative activity was kept after 11 reuses in a batch process of lactose hydrolysis. Thus, the biocomposite proved to be effective as support for enzyme immobilization.


Assuntos
Alginatos , Aspergillus oryzae , Aspergillus oryzae/metabolismo , Estabilidade Enzimática , Enzimas Imobilizadas/química , Gelatina , Hidrólise , Iridoides , Lactose/química , Espalhamento a Baixo Ângulo , Difração de Raios X , beta-Galactosidase/metabolismo
7.
Carbohydr Polym ; 291: 119575, 2022 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-35698339

RESUMO

Nacre, exhibiting excellent mechanical strengths due to its hierarchical structures, becomes a potential model to design bone implants. Herein, we firstly fabricated nacre-mimetic hydroxyapatite/chitosan/gelatin (HA/CS/Gel) layered scaffolds and incorporated substance P (SP) peptides. The CS scaffolds with a layered architecture could regulate the deposition of HA nanoplates on the interlamellar CS sheets by using CaCO3 as precursors. The HA/CS/Gel layered scaffolds exhibited a great flexure strength of 11.42 MPa due to a brick-and-mortar structure. The biocompatible components, layered macropores and SP peptides in the HA/CS/Gel therapeutic scaffolds facilitated the spreading and proliferation mesenchymal stem cells (MSCs). Notably, the incorporation of SP peptides induced MSC osteogenic differentiation and extracellular matrix mineralization. Rabbit knee subchondral defect models further proved that the HA/CS/Gel-SP layered scaffolds promoted in vivo subchondral bone regeneration. Hence, the combination of nacre-mimetic bone implants and therapeutic drugs may become an attractive strategy for subchondral bone regeneration.


Assuntos
Quitosana , Nácar , Animais , Materiais Biocompatíveis/química , Regeneração Óssea , Células Cultivadas , Quitosana/química , Durapatita/química , Gelatina/química , Osteogênese , Coelhos , Substância P/farmacologia , Engenharia Tecidual , Tecidos Suporte/química
8.
Carbohydr Polym ; 291: 119581, 2022 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-35698340

RESUMO

The effect of wheat bran arabinoxylan (WBAX) with different molecular characteristics on the gelatinization and long-term retrogradation behavior of wheat starch (WS) have been evaluated. WBAXs with Mw of 280-754 kDa and Ara/Xyl of 0.45-0.62 were obtained through alkaline extraction with graded ethanol precipitation. WBAXs with larger Mw and branching degree could impede gelatinization process of wheat starch by effectively decreasing the water availability for starch gelatinization. The hydrogen-bonding interactions between WS and WBAX could enhance the gel strength of WS-WBAX mixed pastes. WBAXs with lower branching degree could inhibit the long-term retrogradation of starch through hindering the rearrangement of amylopectin and double-helical associations of amylose during long-term storage, due to hydrogen-bonding interaction between WBAX and starch. Low-field nuclear magnetic resonance (LF-NMR) relaxometry analysis confirmed that the addition of WBAXs could improve the water holding properties of retrograded starch gels.


Assuntos
Fibras na Dieta , Gelatina , Amilopectina/química , Gelatina/química , Géis/química , Hidrogênio , Amido/química , Água/química , Xilanos
9.
Carbohydr Polym ; 291: 119603, 2022 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-35698406

RESUMO

In this work, the alginate-gelatin conjugates were developed by Maillard reaction. The aerogel templates were obtained by freeze-drying the conjugates, and they were transformed into oleogels by being immersed in camellia oil. Degree of graft and browning index revealed the occurrence of Maillard reaction. Compared with pure alginate/gelatin samples, the rheology and mechanical properties of mixing samples were improved, indicating the interaction of alginate and gelatin. Aerogel templates formed by Maillard reaction presented the micromorphology of lamellar aggregation, obvious changes of peak intensity in infrared spectrum and better thermal stability. The materials reached a considerable oil adsorption capacity of 23.31 g/g and oil holding capacity of 84.75%. Through Maillard reaction, oleogels showed good in vitro digestion properties. This work suggested that oleogels could be constructed from alginate-gelatin conjugates that formed the aerogel templates for oil adsorption, and Maillard reaction significantly affected the physical structures and oil capacities of alginate-gelatin compound systems.


Assuntos
Alginatos , Gelatina , Alginatos/química , Digestão , Compostos Orgânicos/química
10.
ACS Biomater Sci Eng ; 8(6): 2598-2609, 2022 Jun 13.
Artigo em Inglês | MEDLINE | ID: mdl-35649235

RESUMO

Iongels are soft ionic conducting materials, usually composed of polymer networks swollen with ionic liquids (ILs), which are being investigated for applications ranging from energy to bioelectronics. The employment of iongels in bioelectronic devices such as bioelectrodes or body sensors has been limited by the lack of biocompatibility of the ILs and/or polymer matrices. In this work, we present iongels prepared from solely biocompatible materials: (i) a biobased polymer network containing tannic acid as a cross-linker in a gelatin matrix and (ii) three different biocompatible cholinium carboxylate ionic liquids. The resulting iongels are flexible and elastic with Young's modulus between 11.3 and 28.9 kPa. The morphology of the iongels is based on a dual polymer network system formed by both chemical bonding due to the reaction of the gelatin's amines with the polyphenol units and physical interactions between the tannic acid and the gelatin. These biocompatible iongels presented high ionic conductivity values, from 0.003 and up to 0.015 S·cm-1 at room temperature. Furthermore, they showed excellent performance as a conducting gel in electrodes for electromyography and electrocardiogram recording as well as muscle stimulation.


Assuntos
Gelatina , Líquidos Iônicos , Eletrodos , Gelatina/farmacologia , Músculos , Polímeros , Taninos/farmacologia
11.
Theranostics ; 12(9): 4051-4066, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35673575

RESUMO

Bioengineering scaffolds have been improved to achieve efficient regeneration of various damaged tissues. In this study, we attempted to fabricate mechanically and biologically activated 3D printed scaffold in which porous gelatin/hydroxyapatite (G/H) as a matrix material provided outstanding mechanical properties with recoverable behavior, and human placental extracts (hPE) embedded in the scaffold were used as bioactive components. Methods: Various cell types (human adipose-derived stem cells; hASCs, pre-osteoblast; MC3T3-E1, human endothelial cell line; EA.hy926, and human dermal fibroblast; hDFs) were used to assess the effect of the hPE on cellular responses. High weight fraction (~ 70 wt%) of hydroxyapatite (HA) in a gelatin solution supplemented with glycerol was used for the G/H scaffold fabrication, and the scaffolds were immersed in hPE for the embedding (G/H/hPE scaffold). The osteogenic abilities of the scaffolds were investigated in cultured cells (hASCs) assaying for ALP activity and expression of osteogenic genes. For the in vivo test, the G/H and G/H/hPE scaffolds were implanted in the rat mastoid obliteration model. Results: The G/H/hPE scaffold presented unique elastic recoverable properties, which are important for efficient usage of implantable scaffolds. The effects of G/H and G/H/hPE scaffold on various in vitro cell-activities including non-toxicity, biocompatibility, and cell proliferation were investigated. The in vitro results indicated that proliferation (G/H = 351.1 ± 13.3%, G/H/hPE = 430.9 ± 8.7% at day 14) and expression of osteogenic markers (ALP: 3.4-fold, Runx2: 3.9-fold, BMP2: 1.7-fold, OPN: 2.4-fold, and OCN: 4.8-fold at day 21) of hASCs grown in the G/H/hPE scaffold were significantly enhanced compared with that in cells grown in the G/H scaffold. In addition, bone formation was also observed in an in vivo model using rat mastoid obliteration. Conclusion: In vitro and in vivo results suggested that the G/H/hPE scaffold is a potential candidate for use in bone tissue engineering.


Assuntos
Gelatina , Extratos Placentários , Animais , Diferenciação Celular , Proliferação de Células , Durapatita , Feminino , Osteogênese , Placenta , Extratos Placentários/farmacologia , Extratos Vegetais/farmacologia , Gravidez , Impressão Tridimensional , Ratos , Engenharia Tecidual/métodos , Tecidos Suporte
12.
Nat Commun ; 13(1): 3317, 2022 Jun 09.
Artigo em Inglês | MEDLINE | ID: mdl-35680907

RESUMO

Digital light processing bioprinting favors biofabrication of tissues with improved structural complexity. However, soft-tissue fabrication with this method remains a challenge to balance the physical performances of the bioinks for high-fidelity bioprinting and suitable microenvironments for the encapsulated cells to thrive. Here, we propose a molecular cleavage approach, where hyaluronic acid methacrylate (HAMA) is mixed with gelatin methacryloyl to achieve high-performance bioprinting, followed by selectively enzymatic digestion of HAMA, resulting in tissue-matching mechanical properties without losing the structural complexity and fidelity. Our method allows cellular morphological and functional improvements across multiple bioprinted tissue types featuring a wide range of mechanical stiffness, from the muscles to the brain, the softest organ of the human body. This platform endows us to biofabricate mechanically precisely tunable constructs to meet the biological function requirements of target tissues, potentially paving the way for broad applications in tissue and tissue model engineering.


Assuntos
Bioimpressão , Bioimpressão/métodos , Gelatina/química , Humanos , Ácido Hialurônico , Hidrogéis/química , Metacrilatos/química , Impressão Tridimensional , Engenharia Tecidual/métodos , Tecidos Suporte/química
13.
Int J Mol Sci ; 23(11)2022 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-35683001

RESUMO

The reconstruction of bone defects remains challenging. The utilization of bone autografts, although quite promising, is limited by several drawbacks, especially substantial donor site complications. Recently, strontium (Sr), a bioactive trace element with excellent osteoinductive, osteoconductive, and pro-angiogenic properties, has emerged as a potential therapeutic agent for bone repair. Herein, a strontium peroxide (SrO2)-loaded poly(lactic-co-glycolic acid) (PLGA)-gelatin scaffold system was developed as an implantable bone substitute. Gelatin sponges serve as porous osteoconductive scaffolds, while PLGA not only reinforces the mechanical strength of the gelatin but also controls the rate of water infiltration. The encapsulated SrO2 can release Sr2+ in a sustained manner upon exposure to water, thus effectively stimulating the proliferation of osteoblasts and suppressing the formation of osteoclasts. Moreover, SrO2 can generate hydrogen peroxide and subsequent oxygen molecules to increase local oxygen tension, an essential niche factor for osteogenesis. Collectively, the developed SrO2-loaded composite scaffold shows promise as a multifunctional bioactive bone graft for bone tissue engineering.


Assuntos
Estrôncio , Tecidos Suporte , Materiais Biocompatíveis , Regeneração Óssea , Gelatina/farmacologia , Osteoblastos , Osteoclastos , Osteogênese , Oxigênio , Peróxidos/farmacologia , Estrôncio/farmacologia , Engenharia Tecidual , Água
14.
AAPS PharmSciTech ; 23(5): 166, 2022 Jun 16.
Artigo em Inglês | MEDLINE | ID: mdl-35705726

RESUMO

The demand for personalized medicine has received extensive attention, especially in pediatric preparations. An emerging technology, extrusion-based 3D printing, is highly attractive in the field of personalized medicine. In this study, we prepared propranolol hydrochloride (PR) gummy chewable tablets tailored for children by semisolid extrusion (SSE) 3D printing technology to meet personalized medicine needs in pediatrics. In this study, the effects of critical formulation variables on the rheological properties and printability of gum materials were investigated by constructing a full-factorial design. In addition, the masticatory properties, thermal stability, and disintegration time of the preparations were evaluated. Bitterness inhibitors were used to mask the bitterness of the preparations. The results of the full-factorial design showed that the amount of gelatin and carrageenan were the key factors in the formulation. Gelatin can improve printability and masticatory properties, carrageenan can improve thermal stability, and accelerate the disintegration of preparations; therefore, a reasonable combination of both could satisfactorily meet the demand for high-quality 3D printing. γ-Aminobutyric acid can reduce the bitterness of gummy chewable tablets to improve medication compliance and the determined formulation (F7) met the quality requirements. In conclusion, the gum material has excellent potential as an extrusion material for 3D printing. The dosage can be adjusted flexibly by the model shape and size. 3D printing has broad prospects in pediatric preparations.


Assuntos
Pediatria , Propranolol , Carragenina , Criança , Liberação Controlada de Fármacos , Excipientes , Gelatina , Géis , Humanos , Medicina de Precisão , Impressão Tridimensional , Comprimidos , Tecnologia Farmacêutica/métodos
15.
Nanoscale ; 14(23): 8525-8533, 2022 Jun 16.
Artigo em Inglês | MEDLINE | ID: mdl-35660804

RESUMO

Over the last decade, three-dimensional (3D) printing technologies have attracted the interest of researchers due to the possibility of fabricating tissue- and organ-like structures with similarities to the organ of interest. One of the most widely used materials for the fabrication of bioinks is gelatin (Gel) due to its excellent biocompatibility properties. However, in order to fabricate stable scaffolds under physiological conditions, the most common approach is to use gelatin methacrylate (GelMA) that allows the crosslinking and therefore the stabilization of the hydrogel through UV crosslinking. The crosslinking process can be harmful to cells thus decreasing total cell viability. To overcome the need for post-printing crosslinking, a new approach of bioink formulation was studied, incorporating the Fluorenylmethoxycarbonyl diphenylalanine (Fmoc-FF) peptide into the Gel bioink. However, although Fmoc-FF possesses excellent mechanical properties, the lack of elasticity and viscosity makes it unsuitable for 3D-printing. Here, we demonstrate that covalent conjugation of two different ethylene glycol (EG) motifs to the Fmoc-FF peptide increases the hydrophilicity and elasticity properties, which are essential for 3D-printing. This new approach for bioink formulation avoids the need for any post-printing manufacturing processes, such as chemical or UV crosslinking.


Assuntos
Etilenoglicol , Gelatina , Dipeptídeos , Etilenos , Fluorenos , Hidrogéis/química , Peptídeos , Fenilalanina , Impressão Tridimensional , Engenharia Tecidual/métodos , Tecidos Suporte/química
16.
Small ; 18(25): e2107888, 2022 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-35607749

RESUMO

A great deal of research has focused on small-scale robots for biomedical applications and minimally invasive delivery of therapeutics (e.g., cells, drugs, and genes) to a target area. Conventional fabrication methods, such as two-photon polymerization, can be used to build sophisticated micro- and nanorobots, but the long fabrication cycle for a single microrobot has limited its practical use. This study proposes a biodegradable spherical gelatin methacrylate (GelMA) microrobot for mass production in a microfluidic channel. The proposed microrobot is fabricated in a flow-focusing droplet generator by shearing a mixture of GelMA, photoinitiator, and superparamagnetic iron oxide nanoparticles (SPIONs) with a mixture of oil and surfactant. Human nasal turbinate stem cells (hNTSCs) are loaded on the GelMA microrobot, and the hNTSC-loaded microrobot shows precise rolling motion in response to an external rotating magnetic field. The microrobot is enzymatically degraded by collagenase, and released hNTSCs are proliferated and differentiated into neuronal cells. In addition, the feasibility of the GelMA microrobot as a cell therapeutic delivery system is investigated by measuring electrophysiological activity on a multielectrode array. Such a versatile and fully biodegradable microrobot has the potential for targeted stem cell delivery, proliferation, and differentiation for stem cell-based therapy.


Assuntos
Gelatina , Metacrilatos , Sistemas de Liberação de Medicamentos/métodos , Humanos , Campos Magnéticos , Células-Tronco
17.
Small ; 18(25): e2106357, 2022 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-35607752

RESUMO

It is well-known that tissue engineering scaffolds that feature highly interconnected and size-adjustable micropores are oftentimes desired to promote cellular viability, motility, and functions. Unfortunately, the ability of precise control over the microporous structures within bioinks in a cytocompatible manner for applications in 3D bioprinting is generally lacking, until a method of micropore-forming bioink based on gelatin methacryloyl (GelMA) was reported recently. This bioink took advantage of the unique aqueous two-phase emulsion (ATPE) system, where poly(ethylene oxide) (PEO) droplets are utilized as the porogen. Considering the limitations associated with this very initial demonstration, this article has furthered the understanding of the micropore-forming GelMA bioinks by conducting a systematic investigation into the additional GelMA types (porcine and fish, different methacryloyl-modification degrees) and porogen types (PEO, poly(vinyl alcohol), and dextran), as well as the effects of the porogen concentrations and molecular weights on the properties of the GelMA-based ATPE bioink system. This article exemplifies not only the significantly wider range of micropore sizes achievable and better emulsion stability, but also the improved suitability for both extrusion and digital light processing bioprinting with favorable cellular responses.


Assuntos
Bioimpressão , Animais , Emulsões , Gelatina/química , Hidrogéis/química , Metacrilatos , Impressão Tridimensional , Suínos , Engenharia Tecidual , Tecidos Suporte/química
18.
Biomed Mater ; 17(4)2022 05 18.
Artigo em Inglês | MEDLINE | ID: mdl-35504270

RESUMO

The influence of coconut oil (CO) on a gelatin-based film was investigated when used as a potential wound dressing material. There is limited study on CO in protein-based wound dressing materials. Therefore, in this study a self-supporting, continuous and homogenous CO incorporated gelatin-based film was formulated and obtained by solution casting method. The influence of CO on physicochemical and thermal properties of gelatin-based film was also determined. Moreover, the effect CO in gelatin films on cell viability and cell migration was analysed with a preliminary cell culture study. Homogenous dispersion of 10% (w/w) CO was obtained in films when 3% (v/w) Tween 80, a surfactant, was incorporated to 20% (w/w) plasticized gelatin film forming solution. Effect of CO on gelatin-based film was observed via phase separation by scanning electron microscopy analysis. Water uptake of gelatin film with no CO, GE film; and 10% (w/w) CO incorporated GE film, GE-CO, were 320% and 210%, respectively, after 3 h in water. Fourier transform infrared spectroscopy analysis showed triglyceride component of CO and increased hydrogen bonding between NH groups of gelatin in GE-CO films. Differential scanning calorimetry results suggested a more ordered structure of GE-CO film due to an increase in melt-like transition temperature and melting enthalpy of GE-CO film. CO content also increased cell viability, assessed by XTT assay since cell viability was approximately 100% when L929 cell culture was incubated with GE-CO of 5-100 µg ml-1. Moreover, GE-CO samples within 5-25 µg ml-1concentration range, increased proliferation of L929 cells since cell viability was significantly higher than the 100% viable cell culture control (P< 0.05) which is also an indication of efficient healing. However, GE decreased viability of L929 cells significantly at 100-10 µg ml-1concentration range (P< 0.05) and were toxic at concentrations of 100, 75 and 50 µg ml-1which decreased ∼50% of the viability of the cells. Scratch Assay to assessin vitrowound healing showed cell migration towards scratch after 24 h as an indication of wound healing only in GE-CO samples. This study showed that, CO could efficiently be added to gelatin-based films for preparation of a primary wound dressing biomaterial which is also demonstrated to have a promising wound healing effect for minor wounds.


Assuntos
Bandagens , Gelatina , Óleo de Coco , Gelatina/química , Água/química
19.
ACS Appl Bio Mater ; 5(6): 2786-2794, 2022 Jun 20.
Artigo em Inglês | MEDLINE | ID: mdl-35576622

RESUMO

Injectable hydrogels have previously demonstrated potential as a temporary scaffold for tissue regeneration or as a delivery vehicle for cells, growth factors, or drugs. However, most injectable hydrogel systems lack a microporous structure, preventing host cell migration into the hydrogel interior and limiting spreading and proliferation of encapsulated cells. Herein, an injectable microporous hydrogel assembled from gelatin/gelatin methacryloyl (GelMA) composite microgels is described. Microgels are produced by a water-in-oil emulsion using a gelatin/GelMA aqueous mixture. These microgels show improved thermal stability compared to GelMA-only microgels and benefit from combined photopolymerization using UV irradiation (365 nm) in the presence of a photoinitiator (PI) and enzymatic reaction by microbial transglutaminase (mTG), which together enable fast curing and tissue adhesion of the hydrogel. The dual-crosslinking approach also allows for the reduction of PI concentration and minimizes cytotoxicity during photopolymerization. When applied for in situ cell encapsulation, encapsulated human dermal fibroblasts and human mesenchymal stem cells (hMSCs) are able to rapidly spread and proliferate in the pore space of the hydrogel. This hydrogel has the potential to enhance hMSC anti-inflammatory behavior through the demonstrated secretion of prostaglandin E2 (PGE2) and interleukin-6 (IL-6) by encapsulated cells. Altogether, this injectable formulation has the potential to be used as a cell delivery vehicle for various applications in regenerative medicine.


Assuntos
Células-Tronco Mesenquimais , Microgéis , Encapsulamento de Células , Gelatina/química , Humanos , Hidrogéis/química , Metacrilatos , Engenharia Tecidual
20.
ACS Appl Bio Mater ; 5(6): 2965-2975, 2022 Jun 20.
Artigo em Inglês | MEDLINE | ID: mdl-35609115

RESUMO

The objective of this research is to develop an imaging method with cationized gelatin nanospheres incorporating molecular beacon (cGNSMB) to visualize an autophagy activity in living cells. Cationized gelatin nanospheres (cGNS) were prepared by the conventional coacervation method, and then molecular beacon (MB) was incorporated into them. The cGNSMB prepared were internalized into cells at a high efficiency. In this study, a starvation medium of serum and amino acids-free was used to induce autophagy. The autophagy activity was confirmed by an immunofluorescence staining for microtubule-associated proteins light chain 3B (LC3B) of an autophagy specific protein. With the autophagy induction time, the number of LC3 fluorescent dots increased, which indicated an increased autophagy activity. As the autophagy-related genes, sequestosome 1 (SQSTM1) and cathepsin F (CTSF), which up-regulate after autophagy induction, were chosen as the targets of cGNSMB. The fluorescence intensity of cGNSMB targeting to SQSTM1 and CTSF increased with the starvation treatment time, which well corresponded with the gene expression results. When applied to cells in different autophagy conditions, the cGNSMB visualized the autophagy activity corresponding with the autophagy condition of cells. From the results obtained, it was concluded that the cGNSMB provide a promising method to visualize the autophagy of cells. The advantage of cGNSMB visualization is to obtain the temporal and spatial information without destroying sample cells.


Assuntos
Nanosferas , Inanição , Autofagia , Gelatina/metabolismo , Humanos , Proteínas Associadas aos Microtúbulos/genética , Proteína Sequestossoma-1/metabolismo
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...