Hierarchic micro-patterned porous scaffolds via electrochemical replica-deposition enhance neo-vascularization.
Neo-vascularization is a key factor in tissue regeneration within porous scaffolds. Here, we tested the hypothesis that micro-patterned scaffolds, with precisely-designed, open micro-channels, might help endothelial cells to produce intra-scaffold vascular networks. Three series of micro-patterned scaffolds were produced via electrochemical replica-deposition of chitosan and cross-linking. All had regularly-oriented micro-channels (ϕ 500 μm), which differed for the inter-channel spacing, at 600, 700, or 900 μm, respectively. Random-pore scaffolds, using the same technique, were taken as controls. Physical-mechanical characterization revealed high water uptake and favorable elastic mechanical behavior for all scaffolds, slightly reduced in the presence of cross-linking and enhanced with the 700 μm-spaced micro-pattern. At MTT assay, mouse endothelial cell viability was >90% at day 1, 3 and 7, confirmed by visual examination with scanning electron microscopy (SEM). Intra-scaffold cell density, at fluorescence analysis, was higher for the 600 μm-spaced and the 700 μm-spaced micro-patterns over the others. The 700 μm-spaced scaffold was selected for the in vivo testing, to be compared to the random-pore one. Neither type produced an inflammatory reaction; both showed excellent tissue ingrowth. Micro-patterned scaffolds enhanced neo-vascularization, demonstrated by immunofluorescent, semi-quantitative analyses. These findings support the use of micro-patterned porous scaffolds, with adequately spaced micro-channels, to promote neo-vascularization.
Department of Biomedical, Surgical and Dental Sciences, Università degli Studi di Milano, Milano (MI), Via Beldiletto 1, Italy.
Elena Maria
EM
Varoni
Lina
L
Altomare
Andrea
A
Cochis
Arash
A
GhalayaniEsfahani
Alberto
A
Cigada
Lia
L
Rimondini
Luigi
L
De Nardo
D000818:Animals; D001672:Biocompatible Materials / Q000009:adverse effects / Q000737:chemistry; D002452:Cell Count; D049109:Cell Proliferation; D002470:Cell Survival; D048271:Chitosan / Q000009:adverse effects / Q000737:chemistry / Q000276:immunology; D003432:Cross-Linking Reagents; D055664:Electrochemical Techniques / Q000379:methods; D042783:Endothelial Cells / Q000166:cytology / Q000502:physiology; D005260:Female; D008297:Male; D008422:Materials Testing; D051379:Mice; D008810:Mice, Inbred C57BL; D008855:Microscopy, Electron, Scanning; D055616:Microtechnology / Q000379:methods; D018919:Neovascularization, Physiologic; D016062:Porosity; D012038:Regeneration / Q000502:physiology; D054457:Tissue Scaffolds / Q000009:adverse effects / Q000737:chemistry*
D001672:Biocompatible Materials; D003432:Cross-Linking Reagents; D048271:Chitosan