scholarly journals Effect of Relative Humidity on the Electrospinning Performance of Regenerated Silk Solution

Polymers ◽  
2021 ◽  
Vol 13 (15) ◽  
pp. 2479
Author(s):  
Bo Kyung Park ◽  
In Chul Um

Recently, the electrospun silk web has been intensively studied in terms of its biomedical applications, including tissue engineering scaffolds, due to its good biocompatibility, cytocompatibility, and biodegradability. In this study, the effect of relative humidity (RH) conditions on the morphology of electrospun silk fiber and the electrospinning production rate of silk solution was examined. In addition, the effect of RH on the molecular conformation of electrospun silk web was examined using Fourier transform infrared (FTIR) spectroscopy. As RH was increased, the maximum electrospinning rate of silk solution and fiber diameter of the resultant electrospun silk web were decreased. When RH was increased to 60%, some beads were observed, which showed that the electrospinnability of silk formic acid solution deteriorated with an increase in RH. The FTIR results showed that electrospun silk web was partially β-sheet crystallized and RH did not affect the molecular conformation of silk.

2021 ◽  
Vol 28 ◽  
Author(s):  
Wei Liu ◽  
Haishun Du ◽  
Ting Zheng ◽  
Chuanling Si

Background: Bacterial cellulose (BC) and its derivatives are a rich source of renewable natural ingredients, which are of great significance for biomedical and medical applications but have not yet been fully exploited. BC is a high-purity, biocompatible, and versatile biomaterial that can be used alone or in combination with other ingredients such as polymers and nanoparticles to provide different structural organization and function. This review briefly introduces the research status of BC hydrogels, focusing on the preparation of BC based composite hydrogels and their applications in the field of biomedicine, particularly the wound dressings, tissue engineering scaffolds, and drug delivery. Methods: By reviewing the most recent literature on this subject, we summarized recent advances in the preparation of BC based composite hydrogels and their advances in biomedical applications, including wound dressings, tissue engineering, and drug delivery. Results: BC composite hydrogels have broadened the field of application of BC and developed a variety of BC-based biomaterials with excellent properties. BC-based hydrogels have good biocompatibility and broad application prospects in the biomedical field. Conclusion: BC based composite hydrogels with the advantages of 3D structure, non-toxicity, high purity, and good biocompatibility, have great prospects in the development of sustainable and multifunctional biomaterials for biomedical applications.


Materials ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1269
Author(s):  
Gareth Sheppard ◽  
Karl Tassenberg ◽  
Bogdan Nenchev ◽  
Joel Strickland ◽  
Ramy Mesalam ◽  
...  

In tissue engineering, scaffolds are a key component that possess a highly elaborate pore structure. Careful characterisation of such porous structures enables the prediction of a variety of large-scale biological responses. In this work, a rapid, efficient, and accurate methodology for 2D bulk porous structure analysis is proposed. The algorithm, “GAKTpore”, creates a morphology map allowing quantification and visualisation of spatial feature variation. The software achieves 99.6% and 99.1% mean accuracy for pore diameter and shape factor identification, respectively. There are two main algorithm novelties within this work: (1) feature-dependant homogeneity map; (2) a new waviness function providing insights into the convexity/concavity of pores, important for understanding the influence on cell adhesion and proliferation. The algorithm is applied to foam structures, providing a full characterisation of a 10 mm diameter SEM micrograph (14,784 × 14,915 px) with 190,249 pores in ~9 min and has elucidated new insights into collagen scaffold formation by relating microstructural formation to the bulk formation environment. This novel porosity characterisation algorithm demonstrates its versatility, where accuracy, repeatability, and time are paramount. Thus, GAKTpore offers enormous potential to optimise and enhance scaffolds within tissue engineering.


2011 ◽  
Vol 493-494 ◽  
pp. 840-843
Author(s):  
Akiko Obata ◽  
Hiroki Ozasa ◽  
Julian R. Jones ◽  
Toshihiro Kasuga

Materials for bone defect filling should have 3D macroporous structure and be flexible to be packed into complex defects with limited entrance space. Tissue engineering scaffolds should also mimic the structure and morphology of the host tissue. Electrospinning is a versatile technique to produce materials with micro/nanofibrous structure, large surface area and high porosity. Electrospun materials are very promising for tissue engineering due to the possibility of mimicking the fibrous structure of natural extra cellular matrix (ECM). Siloxane-containing vaterite (SiV)/poly (L-lactic acid) (PLLA) hybrids (SiPVH) with controlled silicate and calcium ions releasing ability has been produced in our group. They have also demonstrated good cell infiltration into the electrospun hybrid materials that had fiber diameters greater than 10 μm. However, these electrospun hybrid materials were planar (2D) and are not suitable for large defect regeneration. In this work, the development of a fabrication technique for the production of 3D cotton wool-like structures with fiber diameter in the range of 10 μm was performed. SiPVH cotton wool-like structure containing 0, 30 and 60 wt % SiV were prepared by blowing air in the direction perpendicular to fiber spinning. Si-vaterite particles and small pores were found on the surface of the fibers. The fiber diameter of the samples were found to be in the range of 10 ~ 20 μm. Stretch tests showed more than 50 % extension for the SiPVH cotton wool-like material containing 30 wt % SiV (SiPVH30). This extension was similar to that observed for the PLLA cotton wool-like material. The results suggest that the SiPVH30 cotton wool-like material are good candidates for bone tissue engineering scaffolds.


2010 ◽  
Vol 19 (2) ◽  
pp. 096369351001900 ◽  
Author(s):  
M. Mozafari ◽  
F. Moztarzadeh ◽  
M. Rabiee ◽  
M. Azami ◽  
N. Nezafati ◽  
...  

In this research, macroporous, mechanically competent and bioactive nanocomposite scaffolds have been fabricated from cross-linked gelatine (Gel) and nano bioactive glass (nBG) through layer solvent casting combined with freeze-drying and lamination techniques. This study has developed a new composition to produce a new bioactive nanocomposite which is porous with interconnected microstructure, pore sizes are 200-500 μm, porosity are 72%-86%. Also, we have reported formation of chemical bonds between nBG and Gel for the first time. Finally, the in vitro cytocompatability of the scaffolds was assessed using MTT assay and cell attachment study. Results indicated no sign of toxicity and cells found to be attached to the pore walls offered by the scaffolds. These results suggested that the developed nanocomposite scaffold possess the prerequisites for bone tissue engineering scaffolds and it can be used for tissue engineering applications.


2020 ◽  
Vol 7 (10) ◽  
pp. 4032-4040
Author(s):  
Esam Bashir Yahya ◽  
Marwa Mohammed Alzalouk ◽  
Khalifa A. Alfallous ◽  
Abdullah F. Abogmaza

Aerogels have been steadily developed since its first invention to become one of the most promising materials for various medical and non-medical applications. It has been prepared from organic and inorganic materials, in pure forms or composites. Cellulose-based aerogels are considered one of the promising materials in biomedical applications due to their availability, degradability, biocompatibility and non-cytotoxicity compared to conventional silica or metal-based aerogels. The unique properties of such materials permit their utilization in drug delivery, biosensing, tissue engineering scaffolds, and wound dressing. This review presents a summary of aerogel development as well as the properties and applications of aerogels. Herein, we further discuss the recent works pertaining to utilization of cellulose-based aerogels for antibacterial delivery.


Author(s):  
JinGyu Ock ◽  
Wei Li

Selective laser foaming is a novel process that combines solid-state foaming and laser ablation to fabricate an array of microliter tissue engineering scaffolds on a polymeric chip for biomedical applications. In this study, a finite element analysis (FEA) model is developed to investigate the effect of laser processing parameters. Experimental results with biodegradable polylactic acid (PLA) were used for validation. It is found that foaming always occurs before ablation, and once it occurs, the temperature increases dramatically due to an enhanced laser absorption effect of the porous structure. The geometry of the fabricated scaffolds can be controlled by laser parameters. While the depth of scaffolds can be controlled by laser power and lasing time, the diameter is more effectively controlled by the laser power. The model developed in this study can be used to optimize and control the selective foaming process.


Biomaterials ◽  
2006 ◽  
Vol 27 (32) ◽  
pp. 5524-5534 ◽  
Author(s):  
Chantal Ayres ◽  
Gary L. Bowlin ◽  
Scott C. Henderson ◽  
Leander Taylor ◽  
Jackie Shultz ◽  
...  

2006 ◽  
Vol 128 (4) ◽  
pp. 610-622 ◽  
Author(s):  
George C. Engelmayr ◽  
Michael S. Sacks

The development of methods to predict the strength and stiffness of biomaterials used in tissue engineering is critical for load-bearing applications in which the essential functional requirements are primarily mechanical. We previously quantified changes in the effective stiffness (E) of needled nonwoven polyglycolic acid (PGA) and poly-L-lactic acid (PLLA) scaffolds due to tissue formation and scaffold degradation under three-point bending. Toward predicting these changes, we present a structural model for E of a needled nonwoven scaffold in flexure. The model accounted for the number and orientation of fibers within a representative volume element of the scaffold demarcated by the needling process. The spring-like effective stiffness of the curved fibers was calculated using the sinusoidal fiber shapes. Structural and mechanical properties of PGA and PLLA fibers and PGA, PLLA, and 50:50 PGA/PLLA scaffolds were measured and compared with model predictions. To verify the general predictive capability, the predicted dependence of E on fiber diameter was compared with experimental measurements. Needled nonwoven scaffolds were found to exhibit distinct preferred (PD) and cross-preferred (XD) fiber directions, with an E ratio (PD/XD) of ∼3:1. The good agreement between the predicted and experimental dependence of E on fiber diameter (R2=0.987) suggests that the structural model can be used to design scaffolds with E values more similar to native soft tissues. A comparison with previous results for cell-seeded scaffolds (Engelmayr, G. C., Jr., et al., 2005, Biomaterials, 26(2), pp. 175–187) suggests, for the first time, that the primary mechanical effect of collagen deposition is an increase in the number of fiber-fiber bond points yielding effectively stiffer scaffold fibers. This finding indicated that the effects of tissue deposition on needled nonwoven scaffold mechanics do not follow a rule-of-mixtures behavior. These important results underscore the need for structural approaches in modeling the effects of engineered tissue formation on nonwoven scaffolds, and their potential utility in scaffold design.


Crystals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 199
Author(s):  
Arputharaj Joseph Nathanael ◽  
Tae Hwan Oh

In the field of tissue engineering, electrospinning is a versatile technique that provides nanofibers with structure similar to that of the extracellular matrix owing to their flexible functionalization. Considerable developments in electrospinning have been made to produce engineered electrospun nanofibers for different biomedical applications. Various biopolymers possess good biocompatibility and biodegradability and are nontoxic in nature. Modification of these biopolymers can enhance or elicit certain properties. One technique of modification is the incorporation of certain inorganic ions or components that can enhance its specific functional characteristics such as mineralization, osseointegration, and bioactivity. Incidentally, calcium phosphate (CaP) materials have proven to be suitable and versatile for biopolymer incorporation and exploration because of their inherent bioactivity and being key mineral constituents of bone and teeth. The addition of CaP materials to polymers enhances cell infiltration, differentiation, and biomineralization. We aim to provide a broad overview of CaP material (particularly hydroxyapatite (HA))-incorporated electrospun nanocomposite fibers and their possible applications in tissue engineering. Some key polymer/HA composites were discussed in detail, and a brief discussion on other polymer/HA composites was also provided. Finally, we discussed the future perspectives of this interesting and emerging composite material fabricated via electrospinning.


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