 2. Efficacy test of allogenic ASCs injection In the second year, the investigators will assess the efficacy of the ALLO-ASC injection comparing the ALLO-ASC injection group and the placebo group 0.9 normal saline injection by a randomized, open-label, single-blind design. Each group is composed of six patients. Both the clinical assessment and follow-up period are identical with the first-year protocol. 