Production and in vitro evaluation of macroporous, cell-encapsulating alginate fibres for nerve repair.
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 fibres were produced by extraction of gelatin particle porogens from wet spun fibres 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 fibres of 16, 21, and 24% w/w respectively. Between 45 and 60% of the gelatin content of hydrated fibres was released in 1h 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 (48-69μm), 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 150μm 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.
The University of Queensland, Pharmacy Australia Centre of Excellence, 20 Cornwall Street, Woolloongabba, Brisbane QLD 4102, Australia. Electronic address: sharonlin114@gmail.com.
Sharon Chien-Yu
SC
Lin
The University of Queensland, Pharmacy Australia Centre of Excellence, 20 Cornwall Street, Woolloongabba, Brisbane QLD 4102, Australia. Electronic address: yiweiwang@anzac.edu.au.
Yiwei
Y
Wang
Faculty of Science, Engineering and Computing, Kingston University, Kingston upon Thames, Surrey KT1 2EE, UK. Electronic address: d.wertheim@kingston.ac.uk.
David F
DF
Wertheim
Faculty of Pharmaceutical Sciences, Prince of Songkla University, Hat Yai, Songkhla 90112, Thailand. Electronic address: allancoombes@pharmacy.psu.ac.th.
Allan G A
AGA
Coombes
D000464:Alginates / Q000494:pharmacology*; D000818:Animals; D018914:Cells, Immobilized / Q000166:cytology / Q000187:drug effects; D005727:Ganglia, Spinal / Q000166:cytology* / Q000187:drug effects; D005780:Gelatin / Q000648:ultrastructure; D020723:Glucuronic Acid / Q000494:pharmacology; D006603:Hexuronic Acids / Q000494:pharmacology; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate / Q000494:pharmacology*; D021621:Imaging, Three-Dimensional; D018613:Microscopy, Confocal; D009416:Nerve Regeneration / Q000187:drug effects*; D010316:Particle Size; D016062:Porosity; D051381:Rats; D034421:Sus scrofa
D000464:Alginates; D006603:Hexuronic Acids; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate; D020723:Glucuronic Acid; D005780:Gelatin
3D image analysis; Alginate fibre; Dorsal root ganglion; Macropores; Nerve regeneration