Table 1.

Fibril-forming properties of different types of collagen.

	Acid-soluble	Enzyme-treated	Alkali-treated
Molecular structure	intact	telopeptides cleaved	deamidized asparagine and glutamine amino acids and telopeptides cleaved
Gelation	Possible at low concentration of collagen	Possible at high concentration of collagen	at acidic pH with the appearance of non-banded filaments
Ability to form native banded fibrils	Yes	Yes, but less well organized	No
Adhesion of cells to substrata from this type of collagen	Good	Good	Good
Advantages	Ability to form native banded well-ordered collagen fibrils at optimal conditions Ability to form stable collagen gels at very low concentration of collagen	Ability to form collagen gels with a high concentration of collagen Obliquely banded fibrils, FLS and SLS can be obtained	Suitable for the production of non-fibrous collagen materials (films, sponge, etc.)