scholarly journals Silk Protein Composite Bioinks and Their 3D Scaffolds and In Vitro Characterization

2022 ◽  
Vol 23 (2) ◽  
pp. 910
Author(s):  
Ji-Xin Li ◽  
Shu-Xiang Zhao ◽  
Yu-Qing Zhang

This paper describes the use of silk protein, including fibroin and sericin, from an alkaline solution of Ca(OH)2 for the clean degumming of silk, which is neutralized by sulfuric acid to create calcium salt precipitation. The whole sericin (WS) can not only be recycled, but completely degummed silk fibroin (SF) is also obtained in this process. The inner layers of sericin (ILS) were also prepared from the degummed silk in boiling water by 120 °C water treatment. When the three silk proteins (SPs) were individually grafted with glycidyl methacrylate (GMA), three grafted silk proteins (G-SF, G-WS, G-ILS) were obtained. After adding I2959 (a photoinitiator), the SP bioinks were prepared with phosphate buffer (PBS) and subsequently bioprinted into various SP scaffolds with a 3D network structure. The compressive strength of the SF/ILS (20%) scaffold added to G-ILS was 45% higher than that of the SF scaffold alone. The thermal decomposition temperatures of the SF/WS (10%) and SF/ILS (20%) scaffolds, mainly composed of a β-sheet structures, were 3 °C and 2 °C higher than that of the SF scaffold alone, respectively. The swelling properties and resistance to protease hydrolysis of the SP scaffolds containing sericin were improved. The bovine insulin release rates reached 61% and 56% after 5 days. The L929 cells adhered, stretched, and proliferated well on the SP composite scaffold. Thus, the SP bioinks obtained could be used to print different types of SP composite scaffolds adapted to a variety of applications, including cells, drugs, tissues, etc. The techniques described here provide potential new applications for the recycling and utilization of sericin, which is a waste product of silk processing.

2014 ◽  
Vol 4 (1) ◽  
pp. 20130049 ◽  
Author(s):  
R. N. Oliveira ◽  
R. Rouzé ◽  
B. Quilty ◽  
G. G. Alves ◽  
G. D. A. Soares ◽  
...  

Polyvinyl alcohol (PVA) hydrogels are materials for potential use in burn healing. Silver nanoparticles can be synthesized within PVA hydrogels giving antimicrobial hydrogels. Hydrogels have to be swollen prior to their application, and the common medium available for that in hospitals is saline solution, but the hydrogel could also take up some of the wound's fluid. This work developed gamma-irradiated PVA/nano-Ag hydrogels for potential use in burn dressing applications. Silver nitrate (AgNO 3 ) was used as nano-Ag precursor agent. Saline solution, phosphate-buffered solution (PBS) pH 7.4 and solution pH 4.0 were used as swelling media. Microstructural evaluation revealed an effect of the nanoparticles on PVA crystallization. The swelling of the PVA-Ag samples in solution pH 4.0 was low, as was their silver delivery, compared with the equivalent samples swollen in the other media. The highest swelling and silver delivery were related to samples prepared with 0.50% AgNO 3 , and they also presented lower strength in PBS pH 7.4 and solution pH 4.0. Both PVA-Ag samples were also non-toxic and presented antimicrobial activity, confirming that 0.25% AgNO 3 concentration is sufficient to establish an antimicrobial effect. Both PVA-Ag samples presented suitable mechanical and swelling properties in all media, representative of potential burn site conditions.


2020 ◽  
Vol 35 (1) ◽  
pp. 135-145 ◽  
Author(s):  
Ali Sadeghianmaryan ◽  
Hamed Alizadeh Sardroud ◽  
Sanaz Allafasghari ◽  
Zahra Yazdanpanah ◽  
Saman Naghieh ◽  
...  

Electrospinning polyurethane has been utilized as skin wound dressing for protecting skin wounds from infection and thus facilitating their healings, but also limited by its imperfect biocompatibility, mechanical and antibacterial properties. This paper presents our study on the addition of graphene oxide to electrospinning polyurethane for improved properties, as well as its in vitro characterization. Polyurethane/graphene oxide wound dressing was electrospun with varying amount of graphene oxide (from 0.0% to 2.0%); and in vitro tests was carried out to characterize the wound dressing properties and performance from the structural, mechanical, and biological perspectives. Scanning electron microscopy and Fourier-transform infrared spectroscopy were used to confirm the interaction between graphene oxide particles and polyurethane fibers, while the scanning electron microscopy images further illustrated that the wound dressing was of a porous structure with fibre diameters depending on the amount of graphene oxide added; specifically, 20 to 180 nm were for composite polyurethane/graphene oxide fibers and 600 to 900 nm for pure polyurethane. Our results also revealed that the hydrophilicity and swelling properties of the wound dressing could be regulated by the amount of graphene oxide added to the polyurethane/graphene oxide composites. Mechanical, antibacterial, and cytotoxicity properties of the composite polyurethane/graphene oxide wound dressing were examined with the results illustrating that the addition of graphene oxide could improve the properties of the electrospun wound dressing. Combined together, our study illustrates that electrospinning polyurethane/graphene oxide composite is promising as skin wound dressing.


2018 ◽  
Vol 8 (3) ◽  
pp. 36-41
Author(s):  
Diep Do Thi Hong ◽  
Duong Le Phuoc ◽  
Hoai Nguyen Thi ◽  
Serra Pier Andrea ◽  
Rocchitta Gaia

Background: The first biosensor was constructed more than fifty years ago. It was composed of the biorecognition element and transducer. The first-generation enzyme biosensors play important role in monitoring neurotransmitter and determine small quantities of substances in complex matrices of the samples Glutamate is important biochemicals involved in energetic metabolism and neurotransmission. Therefore, biosensors requires the development a new approach exhibiting high sensibility, good reproducibility and longterm stability. The first-generation enzyme biosensors play important role in monitoring neurotransmitter and determine small quantities of substances in complex matrices of the samples. The aims of this work: To find out which concentration of polyethylenimine (PEI) exhibiting the most high sensibility, good reproducibility and long-term stability. Methods: We designed and developed glutamate biosensor using different concentration of PEI ranging from 0% to 5% at Day 1 and Day 8. Results: After Glutamate biosensors in-vitro characterization, several PEI concentrations, ranging from 0.5% to 1% seem to be the best in terms of VMAX, the KM; while PEI content ranging from 0.5% to 1% resulted stable, PEI 1% displayed an excellent stability. Conclusions: In the result, PEI 1% perfomed high sensibility, good stability and blocking interference. Furthermore, we expect to develop and characterize an implantable biosensor capable of detecting glutamate, glucose in vivo. Key words: Glutamate biosensors, PEi (Polyethylenimine) enhances glutamate oxidase, glutamate oxidase biosensors


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