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1.
J Photochem Photobiol B ; 202: 111680, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31810038

RESUMO

Tissue engineering and stem cell rehabilitation are the hopeful aspects that are being investigated for the management of Myocardial Infarction (MI); cardiac patches have been used to start myocardial rejuvenation. In this study, we engineered p-phenylenediamine surface functionalized (modif-CQD) into the Silk fibroin/PLA (SF/PLA) nanofibrous bioactive scaffolds with improved physico-chemical abilities, mechanical and cytocompatibility to cardiomyocytes. The micrograph results visualized the morphological improved spherical modif-CQD have been equivalently spread throughout the SF/PLA bioactive cardiac scaffolds. The fabricated CQD@SF/PLA nanofibrous bioactive scaffolds were highly porous with fully consistent pores; effectively improved young modulus and swelling asset for the suitability and effective implantation efficacy. The scaffolds were prepared with rat cardiomyocytes and cultured for up to 7 days, without electrical incentive. After 7 days of culture, the scaffold pores all over the construct volume were overflowing with cardiomyocytes. The metabolic activity and viability of the cardiomyocytes in CQD@SF/PLA scaffolds were significantly higher than cardiomyocytes in Silk fibroin /PLA scaffolds. The integration of CQD also influenced greatly and increases the expression of cardiac-marker genes. The results of the present investigations evidently recommended that well-organized cardiac nanofibrous scaffold with greater cardiac related mechanical abilities and biocompatibilities for cardiac tissue engineering and nursing care applications.


Assuntos
Fibroínas/química , Nanofibras/química , Pontos Quânticos/química , Engenharia Tecidual , Tecidos Suporte/química , Animais , Materiais Biocompatíveis/química , Materiais Biocompatíveis/farmacologia , Carbono/química , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Raios Infravermelhos , Miócitos Cardíacos/citologia , Miócitos Cardíacos/metabolismo , Nanofibras/toxicidade , Poliésteres/química , RNA Mensageiro/metabolismo , Ratos , Troponina C/genética , Troponina C/metabolismo
2.
Carbohydr Polym ; 227: 115335, 2020 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-31590851

RESUMO

Thiolated chitosan (CS-NAC) was synthesized and the selected CS-NAC was used together with silk fibroin (SF) to produce dual network CS-NAC/SF hydrogels. The CS-NAC/SF solutions with formulated compositions were able to form hydrogels at physiological temperature and pH. Rheological measurements showed that elastic modulus of some CS-NAC/SF gels could reach around 3 kPa or higher and was much higher than their respective viscous modulus, indicating that they behaved like strong gels. Deformation measurements verified that CS-NAC/SF gels had well-defined elasticity. The optimized CS-NAC/SF gels exhibited jointly enhanced properties in terms of strength, stiffness and elasticity when compared to the gels resulted from either CS-NAC or SF. Examinations of dry CS-NAC/SF gels revealed that they were highly porous with well-interconnected pore features. Cell culture demonstrated that CS-NAC/SF gels supported the growth of chondrocytes while effectively maintaining their phenotype. Results suggest that these dual network gels have promising potential in cartilage repair.


Assuntos
Cartilagem Articular , Quitosana/química , Fibroínas/química , Hidrogéis/química , Compostos de Sulfidrila/química , Engenharia Tecidual , Animais , Proliferação de Células , Sobrevivência Celular , Células Cultivadas , Condrócitos , Coelhos , Tecidos Suporte
3.
J Surg Res ; 245: 31-44, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31400575

RESUMO

Treatment of full-thickness skin wounds with minimal scarring and complete restoration of native tissue properties still exists as a clinical challenge. A bilayer skin substitute was fabricated by coating human amniotic membrane (AM) with electrospun silk fibroin nanofibers, and its in vivo biological behavior was studied using murine full-thickness skin wound model. Donut-shaped silicon splints were utilized to prevent wound contraction in mouse skin and simulate re-epithelialization, which is the normal path of human wound healing. Skin regeneration using the bilayer scaffold was compared with AM and untreated defect after 30 d. Tissue samples were taken from healed wound areas and investigated through histopathological and immunohistochemical staining to visualize involucrin (IVL), P63, collagen I, CD31, and vascular endothelial growth factor. In addition, mRNA expression of IVL, P63, interleukin-6, and cyclooxygenase-2 was studied. The application of bilayer scaffold resulted in the best epidermal and dermal regeneration, demonstrated by histopathological examination and molecular analysis. In regenerated wounds of the bilayer scaffold group, the mRNA expression levels of inflammatory markers (interleukin-6 and cyclooxygenase-2) were downregulated, and the expression pattern of keratinocyte markers (IVL and P63) at both mRNA and protein levels was more similar to native tissue in comparison with AM and no-treatment groups. There was no significant difference in the expression level of collagen I, CD31, and vascular endothelial growth factor among different groups. Conclusively, these promising results serve as a supporting evidence for proceeding to clinical phase to examine the capacity of this bilayer scaffold for human skin regeneration.


Assuntos
Cicatriz/prevenção & controle , Reepitelização , Pele Artificial , Pele/lesões , Ferimentos e Lesões/terapia , Animais , Cicatriz/etiologia , Modelos Animais de Doenças , Feminino , Fibroínas/química , Humanos , Camundongos , Nanofibras/química , Tecidos Suporte/química , Ferimentos e Lesões/complicações
4.
Int J Nanomedicine ; 14: 9745-9761, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31849466

RESUMO

Introduction: Cancer gene therapy requires both effective tumor suppressor genes and safe vectors that express target genes efficiently. Inhibitor of growth 4 (ING4) inhibits tumor growth via multiple pathways. Interleukin-24 (IL-24) also has tumor-suppressive activity against a broad spectrum of human cancers. Adenovirus (Ad) vectors exhibit high infection efficiency, but potential toxicity related to high doses of adenovirus has led to careful reconsideration of their use in human clinical trials. Antheraea pernyi silk fibroin (ASF) is a cytocompatible and biodegradable natural polymer, and it possesses Arg-Gly-Asp sequences exhibiting a high binding affinity and selectivity for αvß3 and αvß5 integrin receptors, which are overexpressed in tumor vessels and most tumor cells. Methods: In this study, an Arg-Gly-Asp peptide-modified Ad vector coexpressing ING4 and IL-24 was constructed by homologous recombination of the dual gene coexpression transfer plasmid and RGD-modified pAdEasy-1 adenoviral backbone plasmid. The cationic ASF (CASF) was prepared by modifying ASF with low-molecular-weight PEI. The negatively charged Ad vector was modified with CASF to form a CASF/Ad complex. Results: Human hepatoma carcinoma SMMC-7721 cells and normal hepatic L-02 cells were infected with the CASF/Ad complex, which showed significantly higher infection efficiency than the naked Ad. The CASF/Ad complex could effectively mediate the expression of the target gene ING4 in SMMC-7721 cells and the secretion of the target gene IL-24 from SMMC-7721 cells, thus inducing apoptosis of hepatoma carcinoma SMMC-7721 cells. The viability of SMMC-7721 and L-02 cells infected with the CASF/Ad complex was further assessed, and it was found that the growth of SMMC-7721 cells was significantly inhibited but that the growth and proliferation of L-02 cells were not affected. Conclusion: The CASF/Ad complex constructed in this study, showing improved infection efficiency and enhanced suppressive effects on human hepatoma carcinoma SMMC-7721 cells, has the potential to reduce the dose of adenovirus and still maintain high infection efficiency and tumor inhibition.


Assuntos
Carcinoma Hepatocelular/terapia , Proteínas de Ciclo Celular/genética , Vetores Genéticos/genética , Proteínas de Homeodomínio/genética , Interleucinas/genética , Neoplasias Hepáticas/terapia , Mariposas/química , Proteínas Supressoras de Tumor/genética , Adenoviridae/genética , Animais , Apoptose/genética , Carcinoma Hepatocelular/genética , Carcinoma Hepatocelular/patologia , Cátions , Linhagem Celular Tumoral , Fibroínas/química , Fibroínas/genética , Genes Supressores de Tumor , Terapia Genética/métodos , Humanos , Neoplasias Hepáticas/genética , Neoplasias Hepáticas/patologia
5.
Nat Commun ; 10(1): 4378, 2019 09 26.
Artigo em Inglês | MEDLINE | ID: mdl-31558722

RESUMO

Web spiders connect silk proteins, so-called spidroins, into fibers of extraordinary toughness. The spidroin N-terminal domain (NTD) plays a pivotal role in this process: it polymerizes spidroins through a complex mechanism of dimerization. Here we analyze sequences of spidroin NTDs and find an unusually high content of the amino acid methionine. We simultaneously mutate all methionines present in the hydrophobic core of a spidroin NTD from a nursery web spider's dragline silk to leucine. The mutated NTD is strongly stabilized and folds at the theoretical speed limit. The structure of the mutant is preserved, yet its ability to dimerize is substantially impaired. We find that side chains of core methionines serve to mobilize the fold, which can thereby access various conformations and adapt the association interface for tight binding. Methionine in a hydrophobic core equips a protein with the capacity to dynamically change shape and thus to optimize its function.


Assuntos
Fibroínas/metabolismo , Metionina/metabolismo , Seda/metabolismo , Aranhas/metabolismo , Algoritmos , Sequência de Aminoácidos , Animais , Fibroínas/química , Fibroínas/genética , Interações Hidrofóbicas e Hidrofílicas , Metionina/genética , Mutação , Conformação Proteica , Dobramento de Proteína , Multimerização Proteica , Homologia de Sequência de Aminoácidos , Seda/química , Espectrometria de Fluorescência , Aranhas/genética , Termodinâmica
6.
Mater Sci Eng C Mater Biol Appl ; 105: 110018, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31546346

RESUMO

Osteoarthritis is caused by injuries and cartilage degeneration. Cartilage tissue engineering provides new ideas for the treatment of osteoarthritis. Herein, the different ratios composite membranes of silk fibroin/collagen type II were constructed (SF50-50:50, SF70-70:30, SF90-90:10). The surface properties of the composite membranes and chondrocyte morphology were observed by SEM (scanning electron microscopy). Physical functionality as well as stability of composite membranes was evaluated from tensile mechanical properties, the percentage of swelling and degradation. The tensile mechanical behavior of SF70 composite membranes was also predicted based on the constitutive model established in this study, and it is found that the experimental results and predictions were in good agreement. Biocompatibility was evaluated using chondrocytes (ADTC-5) culture. Cell proliferation was analyzed and the treatment of live/dead double staining was performed to assess the viability on chondrocytes. To sum up, SF70 showed the suitable morphology, physical stability, and biological functionality to promote proliferation of chondrocytes. This indicates that the mixing ratio of SF70 shows promise in the future as a scaffold material for cartilage repair.


Assuntos
Materiais Biocompatíveis/química , Colágeno Tipo II/química , Fibroínas/química , Teste de Materiais , Fenômenos Mecânicos , Membranas Artificiais , Animais , Bovinos , Adesão Celular , Linhagem Celular , Proliferação de Células , Forma Celular , Condrócitos/citologia , Condrócitos/ultraestrutura , Humanos , Resistência à Tração
7.
Mater Sci Eng C Mater Biol Appl ; 105: 110093, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31546364

RESUMO

Millions of people worldwide suffer from vision impairing conditions resulting from corneal injury or disease. Silk fibroin (SF) is an emerging biopolymer that has been used for several applications including the fabrication of bioengineered corneas and ocular prostheses. To improve the cell response to SF, riboflavin (RF) and all-trans retinoic acid (RA) were coupled onto SF matrices. RF is a photo-initiator that has previously been combined with ultraviolet light to crosslink corneal collagen while RA has been used to regulate the phenotype of corneal stromal cells and their extracellular matrix deposition. Different concentrations of RF and RA were respectively photo-crosslinked and covalently bound through carbodiimide coupling onto 2% SF matrices. The effect of incorporating these molecules on the physical, chemical and mechanical properties of the matrices was evaluated. The biological response of human corneal stromal cells to the matrices was examined using cellular adhesion assays, proliferation assays, cytoskeleton staining, gene expression analysis and immunocytochemical staining. RF and RA both led to changes in the surface nanostructure and hydrophilicity while just RF increased the material stiffness. Cells cultured on the matrices containing both biomolecules displayed improved cellular proliferation, increased GAG deposition and increased expression of keratocyte genes that are normally associated with healthy corneal stromal tissue. These in vitro studies serve as a starting point for the optimization of loading bioactive molecules on SF based matrices for formulating clinically relevant ocular implants.


Assuntos
Córnea/metabolismo , Ceratócitos da Córnea/metabolismo , Fibroínas/química , Riboflavina/química , Engenharia Tecidual , Tecidos Suporte/química , Tretinoína/química , Córnea/citologia , Ceratócitos da Córnea/citologia , Humanos
8.
Mater Sci Eng C Mater Biol Appl ; 105: 110131, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31546376

RESUMO

Silk fibroin membrane displays potential for ocular tissue reconstruction as demonstrated by its ability to support a functioning retinal pigment epithelium (RPE) in vitro. Nevertheless, translation of these findings to the clinic will require the use of membranes that can be readily handled and implanted into diseased retinas, with minimal impact on the surrounding healthy tissue. To this end, we optimized the physical properties of fibroin membranes to enable surgical handling during implantation into the retina, without compromising biocompatibility or permeability. Our central hypothesis is that optimal strength and permeability can be achieved by combining the porogenic properties of poly(ethylene glycol) (PEG) with the crosslinking properties of horseradish peroxidase (HRP). Our study reveals that PEG used in conjunction with HRP enables the production of fibroin membranes with superior handling properties to conventional fibroin membranes. More specifically, the modified membranes could be more easily implanted into the retinas of rats and displayed good evidence of biocompatibility. Moreover, the modified membranes retained the ability to support construction of functional RPE derived from pluripotent stem cells. These findings pave the way for preclinical studies of RPE-implantation using the optimized fibroin membranes.


Assuntos
Fibroínas/química , Membranas Artificiais , Próteses Visuais , Animais , Bombyx , Células-Tronco Embrionárias Humanas/citologia , Humanos , Peptídeos e Proteínas de Sinalização Intercelular/metabolismo , Permeabilidade , Fagocitose , Ratos , Epitélio Pigmentado da Retina/citologia , Soluções , Espectroscopia de Infravermelho com Transformada de Fourier , Resistência à Tração
9.
Mater Sci Eng C Mater Biol Appl ; 104: 109986, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31499995

RESUMO

Mesenchymal stem cells (MSCs) or epidermal stem cells (ESCs) may be used as a source of cells for skin wound repair in order to preserve the patient's remaining autologous skin and reduce the wound area and pain. Many studies use MSCs as therapeutic cells for wound healing, but treatment with ESCs instead can speed up wound repair. In additional to therapeutic cells, the biomechanical properties and surface topography of the dressing also affect the speed of wound healing. Silk fibroin (SF) has the property of promoting collagen regeneration to accelerate wound healing. It has made into nanofibers as a wound healing dressing with hydrophilic polyvinyl alcohol (PVA). Methanol-treated PVA-SF dressing (PFSM) is a beadless nanofiber that can mimic the structure of endogenous extracellular matrix. In this study, SHED was first differentiated into ESCs and then effects of SHED and ESCs on wound closure were compared. Differentiation of SHED into ESCs was shown to induce growth factors that reached a maximum on the third day. In vivo, PFSM/ESC showed regeneration of granulation tissue on the third day, and the wound closure percent was 53.49%, which was 1.18-fold higher than PFSM/SHED. Therefore, the differentiation of stem cells into ESCs in advance combined with PFSM dressing can effectively accelerate wound healing in vivo. These findings can be applied to clinical treatment in the future.


Assuntos
Diferenciação Celular/fisiologia , Células Epidérmicas/citologia , Fibroínas/química , Nanofibras/química , Álcool de Polivinil/química , Células-Tronco/citologia , Dente Decíduo/citologia , Cicatrização/efeitos dos fármacos , Animais , Bandagens , Colágeno/metabolismo , Matriz Extracelular/metabolismo , Humanos , Masculino , Ratos , Ratos Sprague-Dawley , Pele/efeitos dos fármacos , Pele/metabolismo
10.
Mater Sci Eng C Mater Biol Appl ; 104: 110003, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31500012

RESUMO

Hemostatic materials could reduce avertible death from bleeding during surgery and emergency treatment. To this end, silk fibroin (SF) loaded with Ca2+ (1.8, 3.6 5.4, or 7.2%, w:w) was tested as a new hemostatic material (designated as SF1.8, SF3.6, SF5.4, or SF7.2), and the Ca2+ release rate, platelet adhesion, blood coagulation, cytocompatibility, and antimicrobial properties were investigated. Platelet adhesion on SF1.8 was improved significantly compared with pure SF porous material, and increased with increasing Ca2+ concentration. For SF3.6, platelet adhesion was greater than observed for gelatin and calcium alginate porous materials, clotting occurred earlier, and the complete coagulation time was shorter. Additionally, rabbit ear wound studies revealed that the hemostatic time for SF3.6 was significantly shorter than for gelatin, and similar to that for calcium alginate. The shed blood weight was lowest when SF was loaded with 7.2% Ca2+. The SF3.6 porous material displayed no obvious cytotoxicity, and exhibited satisfactory antibacterial activity against Escherichia coli and Staphylococcus aureus.


Assuntos
Alginatos/química , Materiais Biocompatíveis/química , Cálcio/metabolismo , Fibroínas/química , Seda/química , Animais , Antibacterianos/química , Plaquetas/efeitos dos fármacos , Escherichia coli/efeitos dos fármacos , Gelatina/metabolismo , Hemostáticos/metabolismo , Porosidade/efeitos dos fármacos , Coelhos , Staphylococcus aureus/efeitos dos fármacos , Tecidos Suporte
11.
Mater Sci Eng C Mater Biol Appl ; 104: 109890, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31500018

RESUMO

A protein-polymer blend system based on silkworm silk fibroin (SF) and polylactic acid (PLA) was systematically investigated to understand the interaction and miscibility of proteins and synthetic biocompatible polymers in the macro- and micro-meter scales, which can dramatically control the cell responses and enzyme biodegradation on the biomaterial interface. Silk fibroin, a semicrystalline protein with beta-sheet crystals, provides controllable crystal content and biodegradability; while noncrystallizable PDLLA provides hydrophobicity and thermal stability in the system. Differential scanning calorimetry (DSC) combined with scanning electron microscope (SEM) showed that the morphology of the blend films was uniform on a macroscopic scale, yet with tunable micro-phase patterns at different mixing ratios. Fourier transform infrared analysis (FTIR) revealed that structures of the blend system, such as beta-sheet crystal content, gradually changed with the mixing ratios. All blended samples have better stability than pure SF and PLA samples as evidenced by thermogravimetric analysis. Protease XIV enzymatic study showed that the biodegradability of the blend samples varied with their blending ratios and microscale morphologies. Significantly, the topology of the micro-phase patterns on the blends can promote cell attachment and manipulate the cell growth and proliferation. This study provided a useful platform for understanding the fabrication strategies of protein-synthetic polymer composites that have direct biomedical and green chemistry applications.


Assuntos
Fibroínas/química , Poliésteres/química , Polímeros/química , Seda/química , Animais , Materiais Biocompatíveis/química , Bombyx/química , Varredura Diferencial de Calorimetria/métodos , Microscopia Eletrônica de Varredura/métodos , Espectroscopia de Infravermelho com Transformada de Fourier/métodos
12.
Molecules ; 24(18)2019 Sep 08.
Artigo em Inglês | MEDLINE | ID: mdl-31500392

RESUMO

Celastrol (CL), a bioactive compound isolated from Tripterygium wilfordii, has demonstrated bioactivities against a variety of diseases including cancer and obesity. However, its poor water solubility and rapid in vivo clearance limit its clinical applications. To overcome these limitations, nanotechnology has been employed to improve its pharmacokinetic properties. Nanoparticles made of biological materials offer minimal adverse effects while maintaining the efficacy of encapsulated therapeutics. Silk fibroin (SF) solution was prepared successfully by extraction from the cocoons of silkworms, and a final concentration of 2 mg/mL SF solution was used for the preparation of CL-loaded SF nanoparticles (CL-SFNP) by the desolvation method. A stirring speed of 750 rpm and storage time of 20 h at -20 °C resulted in optimized product yield. A high-performance liquid chromatography (HPLC) method was developed and validated for the analysis of CL in rat plasma in terms of selectivity, linearity, intra-/inter-day precision and accuracy, and recovery. No interference was observed in rat plasma. Linearity in the concentration range of 0.05-5 µg/mL was observed with R2 of 0.999. Precision and accuracy values were below the limit of acceptance criteria, i.e., 15% for quality control (QC) samples and 20% for lower limit of quantification (LLOQ) samples. Rats were given intravenous (IV) administration of 1 mg/kg of pure CL in PEG 300 solution or CL-SFNP. The pharmacokinetic profile was improved with CL-SFNP compared to pure CL. Pure CL resulted in a maximum concentration (Cmax) value of 0.17 µg mL-1 at 5 min following administration, whereas that for CL-SFNP was 0.87 µg mL-1 and the extrapolated initial concentrations (C0) were 0.25 and 1.09 µg mL-1, respectively, for pure CL and CL-SFNP. A 2.4-fold increase in total area under the curve (AUC0-inf) (µg h mL-1) was observed with CL-SFNP when compared with pure CL. CL-SFNP demonstrated longer mean residence time (MRT; 0.67 h) than pure CL (0.26 h). In conclusion, the preparation of CL-SFNP was optimized and the formulation demonstrated improved pharmacokinetic properties compared to CL in solution following IV administration.


Assuntos
Fibroínas/química , Triterpenos/administração & dosagem , Triterpenos/farmacocinética , Administração Intravenosa , Animais , Área Sob a Curva , Disponibilidade Biológica , Cromatografia Líquida de Alta Pressão , Masculino , Nanopartículas , Tamanho da Partícula , Ratos , Ratos Sprague-Dawley , Triterpenos/química
13.
Adv Mater ; 31(48): e1904311, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31490597

RESUMO

Spider silks are tougher than almost all other materials in the world and thus are considered ideal materials by scientists and the industry. Although there have been tremendous attempts to prepare fibers from genetically engineered spider-silk proteins, it is still a very large challenge to artificially produce materials with a very high fracture energy, not to mention the high scaling-up requirements because of the extremely low productivity and high cost levels. Here, a facile spider-silk-mimicking strategy is first reported for preparing scalable supertough fibers using the chemical synthesis route. Supertoughness (≈387 MJ m-3 ), more than twice the reported value of common spider dragline silk and comparable to the value of the toughest spider silk, the aciniform silk of Argiope trifasciata, is achieved by introducing ß-sheet crystals and α-helical peptides simultaneously in a pseudoprotein polymer. The process opens up a very promising avenue for obtaining excellent spider fibers.


Assuntos
Fibroínas/química , Ácido Poliglutâmico/análogos & derivados , Seda/química , Animais , Cristalização , Peptídeos/química , Ácido Poliglutâmico/química , Conformação Proteica , Engenharia de Proteínas/métodos , Aranhas , Resistência à Tração
14.
Adv Mater ; 31(44): e1904720, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31532880

RESUMO

There is great interest in developing conductive biomaterials for the manufacturing of sensors or flexible electronics with applications in healthcare, tracking human motion, or in situ strain measurements. These biomaterials aim to overcome the mismatch in mechanical properties at the interface between typical rigid semiconductor sensors and soft, often uneven biological surfaces or tissues for in vivo and ex vivo applications. Here, the use of biobased carbons to fabricate conductive, highly stretchable, flexible, and biocompatible silk-based composite biomaterials is demonstrated. Biobased carbons are synthesized via hydrothermal processing, an aqueous thermochemical method that converts biomass into a carbonaceous material that can be applied upon activation as conductive filler in composite biomaterials. Experimental synthesis and full-atomistic molecular dynamics modeling are combined to synthesize and characterize these conductive composite biomaterials, made entirely from renewable sources and with promising applications in fields like biomedicine, energy, and electronics.


Assuntos
Materiais Biocompatíveis/química , Fibroínas/química , Grafite/química , Linhagem Celular , Quitina/química , Condutividade Elétrica , Fibroblastos/citologia , Temperatura Alta , Fenômenos Mecânicos , Simulação de Dinâmica Molecular , Impressão Tridimensional , Propriedades de Superfície , Madeira/química
15.
AAPS PharmSciTech ; 20(7): 279, 2019 Aug 09.
Artigo em Inglês | MEDLINE | ID: mdl-31399868

RESUMO

Concomitant intake of alcoholic beverages with sustained-release oral formulations may potentially lead to dose dumping. Alcohol-resistance testing is currently a requirement for the manufacturers by regulatory authorities. Silk fibroin produced by silkworm Bombyx mori is suggested in this work as a potential alternative to a narrow spectrum of alcohol-resistant excipients. Oxycodone HCl, tramadol HCl, and flurbiprofen were selected as model drugs and formulated with regenerated silk fibroin either in the form of an amorphous solid dispersion or as a physical mixture and compressed into tablets. Preliminary compactability and tampering-resistance studies were performed. The ethanol-resistance was tested in media containing 5%, 10%, 20%, or 40% (v/v) ethanol concentration. Drug release profiles were compared using f2 similarity factor. Good mechanical tampering-resistance (tensile strength of 14.6 MPa at 400 MPa compression pressure) was obtained for tablets compressed from physical mixture. Tablets compressed from amorphous solid dispersion had lower tensile strength (2.2 MPa) but showed chemical tampering-resistance to extraction by pure ethanol (7.1% of oxycodone HCl after 24 h). Drug release is controlled predominantly by swelling and diffusion. With an increasing ethanol concentration in release medium, the tablets swelled less, resulting in a slower release. This trend was similar for all tested drugs and for both physical states formulations. No dose dumping occurred in the presence of ethanol; therefore, silk fibroin could be considered as an alternative alcohol-resistant excipient for sustained release application.


Assuntos
Preparações de Ação Retardada , Excipientes , Fibroínas/química , Comprimidos
16.
Nanoscale ; 11(34): 15794-15803, 2019 Aug 29.
Artigo em Inglês | MEDLINE | ID: mdl-31432854

RESUMO

Biomimetic scaffolds have been extensively studied for guiding osteogenesis through structural cues. Inspired by the natural bone growth process, we have employed a hierarchical outer-inner dual reinforcing strategy, which relies on the interfacial ionic bond interaction between amine/calcium and carboxyl groups, to build a nanofiber/particle dual strengthened hierarchical silk fibroin scaffold. This scaffold can provide an applicable form of osteogenic structural cue and mimic the natural bone forming process. Owing to the active interaction between compositions located in the outer pore space and the inner pore wall, the scaffold has over 4 times improvement in the mechanical properties, followed by a significant alteration of the cell-scaffold interaction pattern, demonstrated by over 2 times elevation in the spreading area and enhanced osteogenic activity potentially involving the activities of integrin, vinculin and Yes-associated protein (YAP). The in vivo performance of the scaffold identified the inherent osteogenic effect of the structural cue, which promotes rapid and uniform regeneration. Overall, the hierarchical scaffold is promising in promoting uniform bone regeneration through its specific structural cue endowed by its micro-nano construction.


Assuntos
Materiais Biomiméticos/química , Regeneração Óssea , Fibroínas/química , Nanofibras/química , Osteogênese , Tecidos Suporte/química , Animais , Ratos , Ratos Sprague-Dawley
17.
ACS Appl Mater Interfaces ; 11(37): 33684-33696, 2019 Sep 18.
Artigo em Inglês | MEDLINE | ID: mdl-31453678

RESUMO

Cartilage tissue is deprived of intrinsic self-regeneration capability; hence, its damage often progresses to a chronic condition which reduces the quality of life. Toward the fabrication of functional tissue substitutes, three-dimensional (3D) bioprinting has progressed vastly over the last few decades. However, this progress is challenged by the difficulty in developing suitable bioink materials as most of them require toxic chemical cross-linking. In this study, our goal was to develop a cross-linker-free bioink with optimal rheology for polymer extrusion, aqueous, and nontoxic processing and offers structural support for cartilage regeneration. Toward this, we use the self-gelling ability of silk fibroin blends (Bombyx mori and Philosamia ricini) along with gelatin as a bulking agent. Silk and gelatin interact with each other through entanglement and physical cross-linking. The ink was rheologically and structurally optimized for printing efficiency in printing grid-like structures. The printed 3D constructs show optimal swelling capability, degradability, and compressive strength. Further, the construct supports the growth and proliferation of encapsulated chondrocytes and formation of the cartilaginous extracellular matrix as indicated by the increased sulfated glycosaminoglycan and collagen contents. This was further corroborated by the upregulation of chondrogenic gene expression with minimal hypertrophy of chondrocytes. Additionally, the construct demonstrates in vitro and in vivo biocompatibility. Notably, the ink demonstrates good print fidelity for printing anatomical structures such as the human ear enabled by optimized extrudability at adequate resolution. Altogether, the results indicate that the developed cross-linker-free silk-gelatin polymer-based bioink demonstrated high potential for its 3D bioprintability and application in cartilage tissue engineering.


Assuntos
Cartilagem , Condrócitos , Fibroínas/química , Gelatina/química , Impressão Tridimensional , Engenharia Tecidual , Tecidos Suporte/química , Animais , Cartilagem/química , Cartilagem/citologia , Cartilagem/metabolismo , Condrócitos/citologia , Condrócitos/metabolismo , Suínos
18.
Biosens Bioelectron ; 142: 111595, 2019 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-31425973

RESUMO

The present work reports cocoon silk fibroin (SF)as a unique precursor for the in-situ fabrication of well-engineered, stable and leach free gold nanoparticle doped carbonaceous materials (AuNPs@NSC). In principle, at the molecular level, SF has a singular structure that can be converted to a N-doped aromatic carbon structure by heat treatment. The electrochemical properties of the prepared nanocomposite were examined by cyclic voltammetry and differential pulse voltammetry. A flexible three electrode sensor system with AuNPs@NSC-modified working electrodes has been developed, to achieve easy operation and quick and accurate responses. The electrochemical results showed that the sensor made by the AuNPs@NSC-modified working electrode demonstrated high sensitivity for the detection of rutin, which is attributed to the good distribution of the AuNPs on the carbon matrix. Using differential pulse voltammetry (DPV), the AuNPs@NSC electrode was found to have a linear response in the range of 0.11-250 µM and a comparably low limit of detection of 0.02 µM (S/N = 3). To ensure the accuracy and applicability of the sensors, the concentration of rutin in the commodity (rutin capsule, 10 mg/capsule) was examined, and the sensor provided high precision with a minimum relative error (RE) of 3.3%. These findings suggest that AuNPs@NSC can be considered to be a potential electrode material for the development of electrochemical devices and has great potential in extending their application to the flexible sensor field.


Assuntos
Técnicas Biossensoriais/instrumentação , Carbono/química , Fibroínas/química , Ouro/química , Nanocompostos/química , Rutina/análise , Animais , Bombyx/química , Cápsulas , Técnicas Eletroquímicas/instrumentação , Eletrodos , Desenho de Equipamento , Limite de Detecção , Nanopartículas Metálicas/química
19.
Biosensors (Basel) ; 9(3)2019 Aug 28.
Artigo em Inglês | MEDLINE | ID: mdl-31466277

RESUMO

Conductive polymers, owing to their tunable mechanical and electrochemical properties, are viable candidates to replace metallic components for the development of biosensors and bioelectronics. However, conducting fibers/wires fabricated from these intrinsically conductive and mechanically flexible polymers are typically produced without protective coatings for physiological environments. Providing sheathed conductive fibers/wires can open numerous opportunities for fully organic biodevices. In this work, we report on a facile method to fabricate core-sheath poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) PEDOT:PSS-silk fibroin conductive wires. The conductive wires are formed through a wet-spinning process, and then coated with an optically transparent, photocrosslinkable silk fibroin sheath for insulation and protection in a facile and scalable process. The sheathed fibers were evaluated for their mechanical and electrical characteristics and overall stability. These wires can serve as flexible connectors to an organic electrode biosensor. The entire, fully organic, biodegradable, and free-standing flexible biosensor demonstrated a high sensitivity and rapid response for the detection of ascorbic acid as a model analyte. The entire system can be proteolytically biodegraded in a few weeks. Such organic systems can therefore provide promising solutions to address challenges in transient devices and environmental sustainability.


Assuntos
Técnicas Biossensoriais/instrumentação , Técnicas Eletroquímicas/métodos , Fibroínas/química , Polímeros/química
20.
Int J Nanomedicine ; 14: 4261-4276, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31289441

RESUMO

Purpose: In the field of small-caliber vascular scaffold research, excellent vascular remodeling is the key to ensuring anticoagulant function. We prepared an off-the-shelf bi-layered vascular scaffold with a dense inner layer and a loose outer layer and evaluated its remodeling capabilities by in vivo transplantation. Materials and Methods: Based on poly(L-lactide-co-ε-caprolactone) (PLCL), silk fibroin(SF), and heparin (Hep), PLCL/SF/Hep bi-layered scaffolds and PLCL/Hep bi-layered scaffolds were prepared by electrospinning. The inner layer was a PLCL/SF/Hep or PLCL/Hep nanofiber membrane, and the outer layer was PLCL/SF nano yarn. The in vitro tests included a hydrophilicity test, mechanical properties test, and blood and cell compatibility evaluation. The in vivo evaluation was conducted via single rabbit carotid artery replacement and subsequent examinations, including ultrasound imaging, immunoglobulin assays, and tissue section staining. Results: Compared to the PLCL/Hep nanofiber membrane, the hydrophilicity of the PLCL/SF/Hep nanofiber membrane was significantly improved. The mechanical strength met application requirements. Both the blood and cell compatibility were optimal. Most importantly, the PLCL/SF/Hep scaffolds maintained lumen patency for 3 months after carotid artery transplantation in live rabbits. At the same time, CD31 and α-SMA immunofluorescence staining confirmed bionic endothelial and smooth muscle layers remodeling. Conclusion: Using this hybrid strategy, PLCL and SF were combined to manufacture bi-layered small-caliber vascular scaffolds; these PLCL/SF/Hep scaffolds showed satisfactory vascular remodeling.


Assuntos
Fibroínas/química , Heparina/farmacocinética , Poliésteres/química , Engenharia Tecidual/métodos , Tecidos Suporte/química , Animais , Artérias Carótidas , Proliferação de Células , Liberação Controlada de Fármacos , Heparina/química , Células Endoteliais da Veia Umbilical Humana , Humanos , Interações Hidrofóbicas e Hidrofílicas , Teste de Materiais , Nanofibras/química , Adesividade Plaquetária , Próteses e Implantes , Coelhos
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