Novel biomimetic fiber incorporated scaffolds for tissue engineering

Abstract

From a structural perspective, an ideal scaffold ought to possess interconnected macro pores with sizes from 10 to 100 μm to facilitate cell infiltration and tissue formation, as well as similar topography to the natural extracellular matrix (ECM) which would have an impact on cell behavior such as cell adhesion and gene expression. For that purpose, here we developed a fabrication process to incorporate electrospun short fibers within freeze‐dried scaffolds for tissue engineering applications. Briefly, PCL short fibers were first produced from electrospun fibers with ultrasonication method. They were then evenly dispersed in gelatin solution and freeze‐dried to obtain fiber incorporated scaffolds. The resulting scaffolds exhibited hierarchical structure including major pores with sizes ranging from 50 to 150 μm and the short fibers dispersed in the thin walls of major pores, mimicking the fibrous feature of natural ECM. The short fibers were proven to modify the mechanical properties of scaffold and to facilitate cell adhesion and proliferation on the scaffold. As a promising scaffold for tissue engineering and regenerative medicine, the fiber incorporated scaffold may have further biomedical applications, in which the short fibers can act as drug release vehicles for growth factors or other biomolecules to promote vascularization.

Development of biodegradable webs of PLA/PCL blends prepared via electrospinning: Morphological, chemical, and thermal characterization

“…Although chloroform is the most preferred solvent for electrospinning of PCL with relatively less toxicity, unstable Taylor cone formation, resulting in irregular fiber formation limits its usage 29 . For this purpose, researchers tend to use the less toxic solvent systems with solvents such as acetone, acetic acid, formic acid, methanol, and ethanol together with chloroform 4,23,30‐33 . Although many tissue‐engineering surfaces have been studied in the literature on these polymers, most of the studies involve high‐damage solvent systems.…”

Engineering a Highly Biomimetic Chitosan-Based Cartilage Scaffold by Using Short Fibers and a Cartilage-Decellularized Matrix

“…Unlike previous fiber fragmentation methods (e.g., milling, cutting, ultrasonication and aminolysis), for the sake of better dispersing, in our case, short fibers were prepared by having the electrospun aligned PLGA fibers (diameter, 911 ± 140 nm) cut into segments and homogenized with a homogenizer (Figure A). These randomly dispersed short fibers had an average length of 26 ± 21 μm (Figure B).…”

“…51 unloading cycles gave rise to a declining trend, likely due to ionic bond breaking, 46,49,52 in energy dissipation, the engineered highly biomimetic CDM-Fib/CC scaffolds still outperformed. Overall, in spite of the mechanical competency of the CDM-Fib/CC scaffold for implantation in vivo, it is believed that even better mechanical performance could be achieved after conducting a systematic optimization process by taking some critical determinant factors, such as the fiber length, 53,54 mass percentage of the loaded fiber reinforcement, 19,42 and interface bonding strength, 55 into consideration. Both the in vitro and in vivo results indicate that the engineered scaffold of CDM-Fib/CC was highly effective for chondrogenic induction and cartilage regeneration.…”

Controlling Structure with Injectable Biomaterials to Better Mimic Tissue Heterogeneity and Anisotropy

“…Polymer nanofibers can be electrospun onto a collector in an aligned manner, fixed inside a cryo-gel, and then sectioned into desired lengths [147] or simply subjected to ultrasonication. [171] These short fibers can also be made to be magneto-responsive. [172] Similar to this approach, solventassisted spinning has been used without an electric field to produce short fibers with variable surface topographies, such as smooth, porous, or grooved nano and microstructures by modifying the solvent compositions and process parameters (Figure 5G,H).…”