METHOD OF PRODUCING XENOGRAFT WITH MODIFIABLE STIFFNESS PARAMETERS FOR OPHTHALMOSURGERY Russian patent published in 2019 - IPC A61F2/00 

FIELD: medicine.

SUBSTANCE: invention refers to medicine, namely to ophthalmology and can be used to produce transplant-collagen material of required stiffness for performing scleroplastic surgical interventions. Mechanical cleaning and biomaterial fragmentation are performed. Further treatment is performed twice: 10 % ammonia solution for 4 hours, flushed with treated water, treated with 15 % formic acid solution for 1.5 hours, washing with purified water, freezing and thawing the biomaterial, treatment with 6 % hydrogen peroxide solution, sonication, additional fragmentation of the biomaterial. That is followed by ultraviolet cross-linking of the biomaterial collagen by treating it with riboflavin mononucleotide solution and ultraviolet irradiation, dehydration in upward concentration alcohol 30 to 70 vol. %. Package is packed in bottles with 70 % ethyl alcohol and sterilization by ionizing radiation in dose 1.5 Mrad. One of three modes of processing the biomaterial with riboflavin mononucleotide and ultraviolet irradiation is used. Either processing biomaterial with 0.5 % riboflavin mononucleotide solution for 20 minutes and exposing ultraviolet light at wave length 370 nm for 20 minutes with power 9 mWt/cm². Either processing biomaterial with 0.1 % riboflavin mononucleotide solution for 30 minutes and subsequent ultraviolet irradiation with power of 3 mWt/cm² duration of 30 minutes. Either processing biomaterial with 0.25% riboflavin mononucleotide solution for 20 minutes and ultraviolet irradiation with power of 6 mWt/cm for 20 minutes. Ultraviolet cross-linking of the collagen of the biomaterial is carried out on both sides.

EFFECT: method provides higher biocompatibility of the graft and shorter duration of the sclera-fastening operation by obtaining graft material with low, medium and high stiffness.

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