Immobilization of hUC-MSCs conditioned medium on 3D PLLA collagen-coated matrix enhances diabetic wound healing progression

Conditioned medium(CM)derived from human umbilical cord-mesenchymal stem cells(hUC-MSCs)which con-tains numerous amounts of growth factors,has demonstrated potential in treatment of diabetic wounds.However,for practical application,a biodegradable supporting material is needed to hold the CM and fill in the injury site,where deep cavity wounds are often present in diabetic patients.Poly-l-lactic acid matrix coated with collagen(PLLA/CC)is a suitable carrier due to its biodegradability and biocompatibility.Thus,we present a method to immobilize the hUC-MSCs CM on PLLA/CC through freeze-drying process(PLLA/CC CM FD).When seeded on PLLA/CC CM FD,fibroblasts had an increased cellular function in producing collagen;although no enhancement in cell viability was observed.Moreover,implantation of PLLA/CC CM FD on the wound of diabetic rats showed improvement in wound closure and collagen deposition in the wound area.Altogether,this study exhibits the potential of PLLA/CC CM FD as a therapy for diabetic deep cavity wound.