Collagen solubility testing, a quality assurance step for reproducible electro-spun nano-fibre fabrication. A technical note.
Collagen is the main component of the extra-cellular matrix and has been utilised for numerous clinical applications in many forms and products. However, since collagen remains a natural animal-derived biopolymer, variation between batches should be addressed and minimised to ensure reproducibility of the fabrication process. Recently, electro-spinning of collagen has been introduced as a leading technique for the production of bio-mimetic nano-scale scaffolds for tissue-engineering applications. However, no protocols are available that would allow comparisons of the quality of different collagen raw materials prior to the electro-spinning process. In order to bridge this gap we assessed the solubility of various freeze-dried collagens in 0.5 M acetic acid and analysed the solved collagen by gel electrophoresis. We show that raw material of limited solubility in acetic acid will not render high quality electro-spun nano-fibres using hexafluoropropanol. In particular, insoluble collagen directly failed to produce nano-fibres, collagen of reduced solubility produced fused nano-fibres with limited inter-nano-fibre space, whilst purified type-I collagen of high solubility produced smooth, reproducible nano-fibres. Gel electrophoresis confirmed the amount of solubility, as well as qualitative differences in terms of collagen cross-links and collagen types. We recommend this simple and fast step to save costs and to enhance control over the electro-spinning process of collagen. Furthermore, we believe that the solubility test should be introduced prior to any collagenous matrix preparation in order to ensure reproducibility and accuracy.
Tissue Modulation Laboratory, National University of Singapore, Singapore.
D I
DI
Zeugolis
B
B
Li
R R
RR
Lareu
C K
CK
Chan
M
M
Raghunath
D019342:Acetic Acid / Q000737:chemistry; D000818:Animals; D002417:Cattle; D003094:Collagen / Q000737:chemistry* / Q000302:isolation & purification; D003365:Costs and Cost Analysis; D004560:Electricity; D004591:Electrophoresis, Polyacrylamide Gel; D005615:Freezing; D049329:Nanostructures / Q000737:chemistry*; D011786:Quality Control; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012995:Solubility; D013997:Time Factors
D003094:Collagen; D019342:Acetic Acid