Combined therapy for critical limb ischaemia: Biomimetic PLGA microcarriers potentiates the pro-angiogenic effect of adipose tissue stromal vascular fraction cells.

We propose a regenerative solution in the treatment of critical limb ischaemia (CLI). Poly-lactic/glycolic acid microcarriers were prepared and coated with laminin to be sterilized through γ-irradiation of 25 kGy at low temperature. Stromal vascular fraction (SVF) cells were extracted through enzymatic digestion of adipose tissue. Streptozotocin-induced diabetic mice underwent arteriotomy and received an administration of SVF cells combined or not with biomimetic microcarriers. Functional evaluation of the ischaemic limb was then reported, and tissue reperfusion was evaluated through fluorescence molecular tomography. Microcarriers were stable and functional after γ-irradiation until at least 12 months of storage. Mice that received an injection of SVF cells in the ischaemic limb have 22% of supplementary blood supply within this limb 7 days after surgery compared with vehicle, whereas no difference was observed at Day 14. With the combined therapy, the improvement of blood flow is significantly higher compared with vehicle, of about 31% at Day 7 and of about 11% at Day 14. Injection of SVF cells induces a significant 27% decrease of necrosis compared with vehicle. This effect is more important when SVF cells were mixed with biomimetic microcarriers: -37% compared with control. Although SVF cells injection leads to a non-significant 22% proprioception recovery, the combined therapy induces a significant recovery of about 27% compared with vehicle. We show that the combination of SVF cells from adipose tissue with laminin-coated poly-lactic/glycolic acid microcarriers is efficient for critical limb ischaemia therapy in a diabetic mouse model.

Effect of Washes and Centrifugation on the Efficacy of Lipofilling With or Without Local Anesthetic.

BACKGROUND: Among the different parameters that influence fat graft survival and lipofilling success, the use of local anesthetic and the way to process the fat before injection have often been pointed out. Likewise, we evaluated different techniques for processing adipose tissue before its injection and analyzed the quality of the grafts. METHODS: Adipose tissue from the same patient was gently harvested from one side of the abdomen after infiltration of a tumescent solution without lidocaine and from the other side of the abdomen using a tumescent solution containing lidocaine 2%. Harvested tissue was prepared with different protocols, from simple decantation to advanced protocols including single or multiple washes and centrifugations. Each type of processed adipose tissue was then injected subcutaneously into immunodeficient mice. Adipose grafts were collected after 1 month and analyzed by histology with a detailed scoring method. RESULTS: After lidocaine use, decantation protocol led to adipose grafts of poor quality with high resorption rate and oil vacuole formation. Larger grafts were obtained after centrifugation, but centrifugation alone resulted in increased fibrosis and necrosis, with or without the use of lidocaine. Finally, multiple washes and centrifugations greatly improved the quality of the lipografts. CONCLUSIONS: Centrifugation alone is not sufficient and must be associated with multiple washes to improve graft quality. This article aims to provide further evidence of lidocaine and washing/centrifugation effects in fat grafting to provide easy tips aimed at ensuring graft efficiency with a long-term clinical outcome.