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.
Zeugolis
D I
DI
Tissue Modulation Laboratory, National University of Singapore, Singapore.
Li
B
B
Lareu
R R
RR
Chan
C K
CK
Raghunath
M
M
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