Poly(hydroxybutyrate)/chitosan Aligned Electrospun Scaffold as a Novel Substrate for Nerve Tissue Engineering

Abstract

Background:Reconstruction of nervous system is a great challenge in the therapeutic medical field. Nerve tissue engineering is a novel method to regenerate nervous system in human health care. Tissue engineering has introduced novel approaches to promote and guide peripheral nerve regeneration using submicron and nanoscale fibrous scaffolds.Materials and Methods:In this study, 9 wt% poly(3-hydroxybutyrate) (PHB) solutions with two different ratios of chitosan (CTS) (15%, and 20%) were mixed in trifluoroacetic acid as a cosolvent. Thereafter, random and aligned PHB/CTS scaffolds were fabricated by electrospinning method in an appropriate condition.Results:Average diameters for aligned PHB, PHB/CTS 85:15 and PHB/CTS 80:20 were obtained as 675 nm, 740.3 nm, and 870.74 nm, which was lesser than random fibers. The solution components entity authenticity was approved by Fourier transform infrared. The addition of CTS decreased both water droplet contact angle from 124.79° to 43.14° in random and 110.87° to 33.49° in aligned PHB/CTS fibrous scaffold. Moreover, alignment of fibers causes tremendous increase in hydrophilicity of fibrous PHB/CTS substrate. Tensile strength increased from 6.41 MPa for random to 8.73 MPa for aligned PHB/CTS 85:15.Conclusions:Our results indicated that aligned PHB/CTS 85:15 nanofibers are the desired scaffold than the random PHB/CTS nanofibers for application in nerve tissue regeneration.

Review of Hybrid Materials Based on Polyhydroxyalkanoates for Tissue Engineering Applications

“…Contact angle measurements carried out on aligned and random electrospun PHB/CTS revealed that the fibrous scaffolds containing CTS were more hydrophilic than the pure fibers and that the aligned fibers had a lower WCA than random scaffolds. The WCAs of PHB, PHB/15 wt% CTS and PHB/20 wt% CTS are 124°, 62°, 43° for random fibers and 110°, 54°, 43° for aligned electrospun fibers, respectively [ 52 ]. Other works have reported that the addition of CTS improves the hydrophilicity of PHAs [ 53 , 54 , 55 ].…”

Topographical and Biomechanical Guidance of Electrospun Fibers for Biomedical Applications

“…Other studies indicated that hMSCs were able to preferentially differentiate in the presence of aligned fiber patterns, with effects on cell-cell communication through gap junctions [27]. A key aspect concerns cell interaction of cells with aligned fibers and the contribution of mechanical properties of aligned fiber pattern on cell response in comparison with random fibers [35]. Several studies have not surprisingly reported about the improvement of mechanical response (i.e., tensile, flexural) of aligned fibers with respect to random ones, due to the macroscopic (i.e., higher physical interactions and fiber packing) and microscopic (i.e, higher crystallinity) properties induced by the basic principle of electrospinning process.…”

“…Several studies have not surprisingly reported about the improvement of mechanical response (i.e., tensile, flexural) of aligned fibers with respect to random ones, due to the macroscopic (i.e., higher physical interactions and fiber packing) and microscopic (i.e., higher crystallinity) properties induced by the basic principle of electrospinning process. Aligned fibers can be variously assembled to form anisotropic structures with heterogeneous tensile properties along different ways, i.e., differences of over one order of magnitude in the elastic modulus from 0 • to 90 • orientation angles with respect to the applied load direction, thus providing a selective transfer of biomechanical stimuli to cells as required for the repair of tissues as tendon, nerve, skin, and bone, as well as cartilage [35][36][37]. It is well known that the actin cytoskeleton of cells follows the aligned pattern of fibers and helps cells to recover from stretch during mechanical loading [38].…”

Using Humidity to Control the Morphology and Properties of Electrospun BioPEGylated Polyhydroxybutyrate Scaffolds

“…Consequently, electrospun biomaterials have found applications in various fields including tissue engineering and regenerative medicine. 25 A variety of biomaterial scaffolds fabricated by electrospinning PHB with various blends have been reported, and their potential for applications in engineering of bone, 26 , 27 cartilage, 28 nerve, 29 retinal, 30 and muscle tissues 31 among others have been explored. While PHB scaffold morphology and function are influenced by copolymerizing and blending, Wang et al have reported that fiber diameter and pore size in electrospun PHB matrices can also be significantly altered by changes to fabrication parameters, including temperature, voltage, polymer concentration, and distance from the collector plate.…”