Acceleration of diabetic wound healing by a cryopreserved living dermal substitute created by micronized amnion seeded with fibroblasts.

Bioengineered dermal substitutes have been used for the treatment of diabetic ulcers in clinics and achieved satisfactory results. However, constructing traditional tissue engineered dermal substitutes with two-step method is high-cost, time-consuming and greatly decreases fibroblast proliferative activity because of repeated trypsinization. Inthisstudy, we created a 3D micronized amniotic membrane (mAM) and used it as a natural microcarrier for ex vivo culture and amplification of human dermal fibroblasts (HDF) combined with the rotary cell culture system (RCCS). This one-step mAM-RCCS method couldamplify HDF quickly and construct a dermal substitute HDF-mAM simultaneously. To facilitate the clinical application of mAM-RCCS, anoptimized storage method was used.Post-thawing HDF-mAM retained high cell viability, intact cell morphology and active peptide secretion. When transplanted to the wounds of db/db mice, cryopreserved HDF-mAM promoted vascularization and diabetic wound healing significantly. These results demonstrate the potential application of cryopreserved HDF-mAM as a living dermal substitutefor treating diabetic ulcers and other chronic wounds in clinics.