Patent ID: 7943764

Claim:
A method for extraction of sulphated glycosaminoglycans (sGAG) from a biological tissue containing proteoglycans comprising the steps of: (a) mechanically cleaning and washing said tissue, and then reducing said tissue either to small particles or a thin plate, thereby to form a mechanically treated tissue; (b) washing said treated tissue twice with 0.1 N phosphate buffer heated to a temperature of at least about 65° C. and having a pH in the range of 5.8 to 6.0; thereafter (c) holding the washed, treated tissue in a 0.1 N phosphate buffer for a period of at least 15 minutes; then (d) incubating the washed, treated tissue in a 0.1-0.4% solution of activated paipan, heated to a temperature of at least about 65° C., for a period of 6-24 hours, thereby obtaining a tissue digest; (e) thereafter cooling the digest to precipitate tissue and solidify lipids; (f) filtering the digest to remove the precipitated tissue and lipids to form a cleaned digest solution; (g) contacting the cleaned digest solution with a hard collagen carrier, with particle size between 0.01 and 0.35 cm 3 , for a period between 6-24 hours, in order to bind sGAG to said carrier; thereafter (h) washing said collagen carrier with water, then a weak acid solution, and then distilled water; (i) removing sGAG from said collagen carrier using 0.6-1.5 N mineral salt solution in 0.8 acetic acid or using 0.01 to 0.025 N alkali solution to form an eluate containing sGAG; (j) precipitating sGAG from the eluate using ethanol; and (k) separating the sGAG from the eluate using a centrifuge; and (l) washing the sGAG sediment with ethanol or acetone, and then drying and sterilizing the sGAG material thus obtained.