Abstract: The invention relates to a medical device comprising non-sintered bioactive glass particles or fibres having a diameter in the range 5-100 ?m, bioactive glass comprising SiO2, Na2O, CaO, K2O, MgO, B2O3 and P2O5, wherein the amount of SiO2 is 50-65 wt-% of the final total weight, Na2O is 5-26 wt-% of the final total weight, CaO is 10-25 wt-% of the final total weight, K2O is 0-15 wt-% of the final total weight, MgO is 0-6 wt-% of the final total weight, B2O3 is 0-4 wt-% of the final total weight, and P2O5 is 0-4 wt-% of the final total weight, provided that the total amount of Na2O and K2O is 10-30 wt-% of the final total weight The device is essentially drug free. The invention also relates to the use of said composition for treating lesions associated with compromised or poor vascularisation and for preventing avascular fibrosis.