scholarly journals Preparation and characterization of electrospun graphene/silk fibroin conductive fibrous scaffolds

RSC Advances ◽  
2017 ◽  
Vol 7 (13) ◽  
pp. 7954-7963 ◽  
Author(s):  
Yi Yang ◽  
Xili Ding ◽  
Tongqiang Zou ◽  
Ge Peng ◽  
Haifeng Liu ◽  
...  

A conductive fibrous scaffold made of silk fibroin and graphene was developed using electrospinning technique. The 3% G/SF scaffolds showed improved electroactivity and mechanical properties. Moreover, they could support the cell growth in vitro.

Biomolecules ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 1456
Author(s):  
Isabel Matos Oliveira ◽  
Cristiana Gonçalves ◽  
Myeong Eun Shin ◽  
Sumi Lee ◽  
Rui Luis Reis ◽  
...  

Rheumatoid arthritis is a rheumatic disease for which a healing treatment does not presently exist. Silk fibroin has been extensively studied for use in drug delivery systems due to its uniqueness, versatility and strong clinical track record in medicine. However, in general, natural polymeric materials are not mechanically stable enough, and have high rates of biodegradation. Thus, synthetic materials such as gellan gum can be used to produce composite structures with biological signals to promote tissue-specific interactions while providing the desired mechanical properties. In this work, we aimed to produce hydrogels of tyramine-modified gellan gum with silk fibroin (Ty–GG/SF) via horseradish peroxidase (HRP), with encapsulated betamethasone, to improve the biocompatibility and mechanical properties, and further increase therapeutic efficacy to treat rheumatoid arthritis (RA). The Ty–GG/SF hydrogels presented a β-sheet secondary structure, with gelation time around 2–5 min, good resistance to enzymatic degradation, a suitable injectability profile, viscoelastic capacity with a significant solid component and a betamethasone-controlled release profile over time. In vitro studies showed that Ty–GG/SF hydrogels did not produce a deleterious effect on cellular metabolic activity, morphology or proliferation. Furthermore, Ty–GG/SF hydrogels with encapsulated betamethasone revealed greater therapeutic efficacy than the drug applied alone. Therefore, this strategy can provide an improvement in therapeutic efficacy when compared to the traditional use of drugs for the treatment of rheumatoid arthritis.


Molecules ◽  
2021 ◽  
Vol 26 (20) ◽  
pp. 6317
Author(s):  
Masaaki Aoki ◽  
Yu Masuda ◽  
Kota Ishikawa ◽  
Yasushi Tamada

The molecular weight (MW) of regenerated silk fibroin (RSF) decreases during degumming and dissolving processes. Although MW and the MW distribution generally affect polymer material processability and properties, few reports have described studies examining the influences of MW and the distribution on silk fibroin (SF) material. To prepare different MW SF fractions, the appropriate conditions for fractionation of RSF by ammonium sulfate (AS) precipitation process were investigated. The MW and the distribution of each fraction were found using gel permeation chromatography (GPC) and SDS-polyacrylamide electrophoresis (SDS-PAGE). After films of the fractionated SFs formed, the secondary structure, surface properties, and cell proliferation of films were evaluated. Nanofiber nonwoven mats and 3D porous sponges were fabricated using the fractionated SF aqueous solution. Then, their structures and mechanical properties were analyzed. The results showed AS precipitation using a dialysis membrane at low temperature to be a suitable fractionation method for RSF. Moreover, MW affects the nanofiber and sponge morphology and mechanical properties, although no influence of MW was observed on the secondary structure or crystallinity of the fabricated materials.


Molecules ◽  
2020 ◽  
Vol 25 (5) ◽  
pp. 1110
Author(s):  
Nanyak Galam ◽  
Pinar Tulay ◽  
Terin Adali

Breast cancer ranks as the fifth leading cause of death worldwide. Chemotherapy is commonly used directly or as neo-adjuvant therapy for the management of breast cancer with its attendant adverse effects, underscoring the need to develop biocompatible bioactive compounds for pharmacological applications. The aim of this study is to encapsulate carboplatin (CP) with silk fibroin protein (SF) by using an ionic gelation method as a drug carrier system and assess the apoptotic effect on MCF-7 breast cancer cells during in vitro studies. The characterization of silk fibroin encapsulated carboplatin (SFCP) microparticles was analyzed by FTIR spectrophotometer, SEM, Mastersizer, and biodegradation methods. The encapsulation efficiency and release profile of SFCP microparticles were analyzed by an indirect UV–Vis spectrophotometric method. An apoptotic screening of MCF-7 cells was carried out with 10–200 µg/mL CP loaded SFCP, which were cultured for 24, 48, and 72 h. Data were analyzed using the Student’s t test and analysis of variance. FTIR and drug release studies confirmed an interaction of silk fibroin with the carboplatin moiety. SFCP showed successful encapsulation of the carboplatin moiety. Apoptotic screening showed a dose dependent increase in absorbance, indicating significant cell death (p < 0.05). Thus, the direct apoptotic effect of SFCP microparticles on MCF-7 was confirmed.


2014 ◽  
Vol 900 ◽  
pp. 306-311 ◽  
Author(s):  
Xiu Lin Shu ◽  
Qing Shan Shi ◽  
Xiao Bao Xie ◽  
Xiao Mo Huang ◽  
Yi Ben Chen

In order to improvedβ-TCP biocompatibility and cell growth, was chosen to modify β-TCP matrices to produce a γ-PGA/β-TCP composite biomaterial. Then, the morphology, water uptake and retention abilities,in vitrodegradation property in the simulated medium, cytotoxicity of this novel γ-PGA/β-TCP composite is investigated. SEM shows that the γ-PGA/β-TCP composite has a porous structure. By increasing the percentage ofγ-PGA from 0% to 50%, the swelling ratio of the composite s was enhanced from 9.0%to 297%. These data suggested that the surface hydrophilicity, water absorption rate, and swelling ratio were improved by adding γ-PGA to the composite. In the cytocompatibility test, the density of MC3T3-E1 preosteoblasts cells on the PTCP1:1 leachates was almost 110% higher than that on the controls on day 3. Therefore, the γ-PGA/β-TCP composite scaffolds, due to their better hydrophilicity, cytocompatibility, and porous structure, are very promising biomaterials for tissure engineering applications.


2017 ◽  
Vol 32 (3) ◽  
pp. 399-409 ◽  
Author(s):  
Zhenyu Zhong ◽  
Jun Ma

Zinc substituted hydroxyapatite/silk fibroin composite coatings were deposited on titanium substrates at room temperature by electrophoretic deposition. Microscopic characterization of the synthesized composite nanoparticles revealed that the particle size ranged 50–200 nm, which increased a little after zinc substitution. The obtained coatings maintained the phase of hydroxyapatite and they could induce fast apatite formation in simulated body fluid, indicating high bone activity. The cell culturing results showed that the biomimetic hydroxyapatite coatings could regulate adhesion, spreading, and proliferation of osteoblastic cells. Furthermore, the biological behavior of the zinc substituted hydroxyapatite coatings was found to be better than the bare titanium without coatings and hydroxyapatite coatings without zinc, increasing MC3T1-E1 cell differentiation in alkaline phosphatase expression.


2008 ◽  
Vol 396-398 ◽  
pp. 187-190 ◽  
Author(s):  
Raquel Farias Weska ◽  
Grínia M. Nogueira ◽  
Wellington C. Vieira ◽  
Marisa Masumi Beppu

The requirements for scaffolds for bone tissue engineering include appropriate chemistry, morphology and structure to promote cell adhesion and synthesis of new bone matrix. Silk fibroin (SF) represents an important biomaterial for biomedical application, due to its suitable mechanical properties, biodegradability, biocompatibility, and versatility in processing. Our group has developed a new method to obtain a porous SF membrane, and the study of its potential for use as a scaffold for bone regeneration was the aim of this study. Porous membranes were obtained from SF solution, through the compression of a material generated by phase separation. For in vitro calcification experiments, porous SF membrane samples were immersed in SBF at pH 7.4 placed in polyethylene flasks. The experiments were carried out for seven days, at 36.5±0.5 °C. After 48 and 96h, the solutions were changed for fresh SBF with the ion concentration 1.5-fold higher than that of the standard one, to accelerate the calcification process. The characterization of morphology and composition of samples was performed by using scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS), respectively. The SEM micrographs indicated that the porous SF membranes presented calcium phosphate deposits after undergoing in vitro calcification. These results were confirmed by EDS spectra, which showed a stoichiometric molar Ca/P ratio ranging from 1.27 to 1.52. This fact may suggest that calcification deposits consisted of mixtures of HAP (Ca/P ratio = 1.67) and transient HAP precursor phases, such as octacalcium phosphate (Ca/P = 1.33) and dicalcium phosphate dehydrate (Ca/P = 1), indicating early stage mineralization. The porous silk fibroin membrane analysed in the current study is a promising material to be used as scaffolds for bone regeneration.


2006 ◽  
Vol 49 ◽  
pp. 197-202
Author(s):  
Chih Ling Huang ◽  
Ying Yi Lin ◽  
Jiunn Der Liao

Nerve bridging is to suture a biomaterial-made conduit and to overpass the damaged nerve end to end with microsurgery. Poly L-lactide (PLLA) is an excellent biomaterial that has biocompatible, biodegradable and good mechanical properties; it is thus potential to be engineered as nerve conduits and manufactured as scaffolds for nerve tissue replacement. On the other hand, chitosan provides cell affinity and considerably promotes nerves regeneration. This study is to apply plasma processing for PLLA film modification, graft the plasma-modified film with vaporized acrylic acid (AAc) monomers and then immobilize chitosan by amide bonding on the pAAc-grafted surface. This work using plasma-activation and subsequent evaporation of AAc greatly avoids PLLA thermal cracking and remaining the PLLA film in good mechanical properties. Surface morphologies are evaluated by Nano Focus. Electron Spectroscopy for Chemical Analysis (ESCA) and Attenuated Total Reflectance Fourier-Transform Infrared Spectroscopy (ATR-FTIR) are respectively employed for determining elements’ functionalities and chemical structures. Moreover, biological functionalities of the chitosan-immobilized PLLA films are thereafter assessed by antibacterial test and in vitro fibroblastic cell growth assay. The result exhibits that chitosan is immobilized on the modified PLLA films, which is plasma-activated subsequent to the evaporation of AAc. The process does not induce thermal cracking. In vitro fibroblastic cell growth assay on the chitosan-immobilized PLLA films has demonstrated that fibroblast cells on the surface become circular in shape. It decreases cell growth rate and the development of scar tissues, which may thereafter promote the effect of nerve repairing.


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