Alginate hydrogel has a negative impact on in vitro collagen 1 deposition by fibroblasts.
Hydrogels have been widely investigated as 3D culture substrates because of their reported structural similarity to the extracellular matrix (ECM). Limited ECM deposition, however, occurs within these materials, so the resulting "tissues" bear little resemblance to those found in the body. Here matrix deposition by fibroblasts encapsulated within a calcium alginate (Ca-alg) hydrogel was investigated. Although the cells transcribed mRNA for coll Iα over a period of 3 weeks, very little collagen protein deposition was observed within the gel by histology or immunohistochemistry (IHC). Although molecular diffusion demonstrated charge dependency, this did not prevent the flux of both positively and negative charged amino acids through the gel, suggesting that the absence of ECM could not be attributed to substrate limitation. The flux of protein, however, was charge-dependent as proteins with a net negative charge passed quickly through the Ca-alg into the medium. The minimal collagen deposition within the Ca-alg was attributed to a combination of rapid movement of negatively charged procollagen through the gel and steric hindrance of fibril formation.
School of Chemical Engineering, University of Birmingham, Edgbaston, Birmingham, B15 2TT, United Kingdom. a.m.smith@hud.ac.uk
Alan M
AM
Smith
Nicola C
NC
Hunt
Richard M
RM
Shelton
Gurpreet
G
Birdi
Liam M
LM
Grover
D000464:Alginates / Q000378:metabolism*; D000596:Amino Acids / Q000302:isolation & purification; D000818:Animals; D001205:Ascorbic Acid / Q000378:metabolism; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D024042:Collagen Type I / Q000378:metabolism*; D005109:Extracellular Matrix / Q000378:metabolism; D005347:Fibroblasts / Q000166:cytology* / Q000378:metabolism; D020723:Glucuronic Acid / Q000378:metabolism; D006454:Hemoglobins / Q000378:metabolism; D006603:Hexuronic Acids / Q000378:metabolism; D020100:Hydrogels / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D007150:Immunohistochemistry / Q000379:methods; D051379:Mice; D041681:NIH 3T3 Cells; D023822:Tissue Engineering / Q000379:methods
D000464:Alginates; D000596:Amino Acids; D024042:Collagen Type I; D006454:Hemoglobins; D006603:Hexuronic Acids; D020100:Hydrogels; D020723:Glucuronic Acid; D001205:Ascorbic Acid