Production and in vitro evaluation of macroporous, cell-encapsulating alginate fibres for nerve repair

Abstract

The prospects for successful peripheral nerve repair using fibre guides are considered to be enhanced by the use of a scaffold material, which promotes attachment and proliferation of glial cells and axonal regeneration. Macroporous alginate fibers were produced by extraction of gelatin particle porogens from wet spun fibers produced using a suspension of gelatin particles in 1.5% w/v alginate solution. Gelatin loading of the starting suspension of 40.0, 57.0, and 62.5% w/w resulted in gelatin loading of the dried alginate fibers of 16, 21, and 24% w/w respectively. Between 45 and 60% of the gelatin content of hydrated fibers was released in 1 h in distilled water at 37°C, leading to rapid formation of a macroporous structure. Confocal laser scanning microscopy (CLSM) and image processing provided qualitative and quantitative analysis of mean equivalent macropore diameter (48-69 µm), pore size distribution, estimates of maximum porosity (14.6%) and pore connectivity.CLSM also revealed that gelatin residues lined the macropore cavities and infiltrated into the body of the alginate scaffolds, thus, providing cell adhesion molecules, which are potentially advantageous for promoting growth of glial cells and axonal extension. Macroporous alginate fibres encapsulating nerve cells [primary rat dorsal root ganglia (DRGs)] were produced by wet spinning alginate solution containing dispersed gelatin particles and DRGs. Marked outgrowth was evident over a distance of 150 µm at day 11 in cell culture, indicating that pores and channels created within the alginate hydrogel were providing a favourable environment for neurite development. These findings indicate that macroporous alginate fibres encapsulating nerve cells may provide the basis of a useful strategy for nerve repair.

Fundamentals and Current Strategies for Peripheral Nerve Repair and Regeneration

“…5 shows some promising results obtained with natural-origin biomaterials, in particular using silk fibroin, chitosan and alginate polymers. The significant works considering the use of natural-origin biomaterials in PNR are summarized in Table 5 [118][119][120][121][122][123][124][125][126][127][128][129].…”

Phenolic acids, cinnamic acid, and ergosterol as cosmeceutical ingredients: Stabilization by microencapsulation to ensure sustained bioactivity

“…The use of these compounds in cosmeceutical formulations still face constraints related with instability, sensitivity to pH and temperature, easy degradation and low efficacy. To overcome these issues, recent trends pointed out the use of polymeric carriers such as chitosan, alginate and polylactic acids to protect (encapsulate) bioactive compounds [3,13]. Comparatively with ergosterol, and despite the fact that phenolic acids potential as cosmetic ingredients are well reported, very few studies were conducted to describe the incorporation of these molecules into cosmetics (e.g.…”

Polymeric Guide Conduits for Peripheral Nerve Tissue Engineering

“…Silk fibroin (SF) is a non-toxic and non-immunogenic structural protein (Tang et al, 2012;Kundu et al, 2013). SF has superior mechanical properties compared to other natural polymers (Chien-Yu et al, 2016). Jiao et al (2017) fabricated SF/Alg composite scaffolds loaded with NGF, which significantly improved the motor function of rats, via a freeze-drying method.…”