Noriaki Shirahama

Development of Watertight and Bioabsorbable Synthetic Dural Substitutes

We have developed novel watertight and bioabsorbable synthetic dural substitutes. The substitutes were designed such that they had a three-layered structure, and each layer comprised a bioabsorbable copolymer prepared from L-lactide, glycolide, and epsilon-caprolactone. Various copolymers were synthesized, and appropriate compositions were selected for preparing the substitutes based on the results of leakage tests. Experimental substitutes that prevented the leakage of saline through the suture lines between the substitutes and dura mater were prepared. An in vitro study was performed in which the substitutes were sutured to porcine dura mater, and the amount of saline leakage was measured. It was demonstrated that leakage through the suture line could be completely suppressed by using the substitutes we developed along with favorable suturing techniques.

Development of Bioabsorbable DURA MATER

Regeneration of dura mater of the brain is one of the most urgent tasks in the fields of regeneration medicine, considering the facts that we have many patients infected with fatal Creutzfeldt-Jakob disease following transplant of dried dura mater in the brain operations. Hence we designed the artificial dura mater made from poly(L-lactic acid-co-glycolic acid-co-ε-caprolactone). The sutured substitutes have the ability to prevent the leakage of cerebral fluid, would be absorbed in several months and the patient might be free from the possible side effects caused by the implanted materials. The leakage-proof tests for the developed substitutes were carried out and it was demonstrated that the sutured substitutes and dura mater support the pressure of saline as large as 400mmAq without leakage. The dural regeneration experiments were carried out with rabbits and successful regenerations of dura mater were observed. No inflammations were observed around the substitutes throughout the experimental period till the complete absorption of the materials.