In Vitro Characterization of Canine Microfragmented Adipose Tissue Non-Enzymatically Extracted from the Thigh and Lumbar Regions

Abstract

Within the adult canine population, disabilities and symptoms including joint pain and functional impairment are commonly observed in articular cartilage lesions and present a challenging feat in the operating room. Clinical settings require less invasive and more minimally manipulated measures facilitated by innovative and advanced technology. Mesenchymal stem cells have recently been proposed and, furthermore, autologous adipose tissue administration via injection has emerged as a new albeit somewhat controversial therapeutic tool. The purpose of this study is to characterize canine autologous micro-fragmented adipose tissue (micrografts) by mechanical approach without substantial manipulations. Adipose tissue samples collected from six dogs were processed by a Rigenera device and by enzymatic digestion from two different body regions (lumbar and thigh region). Interestingly, the immunophenotypic analysis attested that cells from Rigenera® were highly positive for the mesenchymal stem cells markers CD73 and CD90, less positive for hematopoietic CD45 and CD34, and negative for MHC class II antibodies (which play a role in immune responses). Finally, the Rigenera® technology obtained micrografts with a 35% higher expression of the IL10 gene with relevant anti-inflammatory activities compared to the enzymatic digestion protocol. This evidence suggests a potential improved clinical outcome capable of modulating inflammation and immune responses.

Effects of Autologous Microfragmented Adipose Tissue on Healing of Tibial Plateau Levelling Osteotomies in Dogs: A Prospective Clinical Trial

“…Mechanical procedures for isolating SVF from adipose tissue represent a valid alternative to the enzymatic method, bypassing the ‘minimal manipulation’ limits strictly regulated by European laws [ 73 ]. In accordance with the human literature [ 74 ], in a recent study involving dogs [ 43 ], researchers sampled adipose tissue from the thigh. Subcutaneous adipose tissue is a more accessible and abundant source of stem cells than visceral adipose tissue [ 75 ].…”

“…Therefore, it can only be performed in specialised laboratories [ 41 , 42 ]. In this scenario, companies have developed automatic closed devices that allow the mechanical processing of adipose tissue [ 43 , 44 ]. The mechanical disaggregation of fat tissue results in microfragmented adipose tissue (MFAT), sometimes referred to as SVF from MFAT [ 37 , 44 ].…”

Effects of Intra-Articular Autologous Adipose Micrograft for the Treatment of Osteoarthritis in Dogs: A Prospective, Randomized, Controlled Study

“…Furthermore, the elastosonographic evaluation showed that the tendons treated with MFAT had a lower degree of stiffness than the untreated ones [ 64 ]. The in vitro validation of the Rigenera ® system for MFAT in the canine species was obtained previously, allowing the consequent prospective clinical evaluation in vivo [ 77 ].…”

Updates on mesenchymal stem cell therapies for articular cartilage regeneration in large animal models

“…However, bone marrow extraction is invasive and complicated by low bMSC density (∼7800 MSCs/ml in humans) ( Hernigou et al, 2021 ). Therefore, aMSCs (particularly from joint-associated adipose) are increasingly popular for cartilage regeneration due to highly-available and easily-accessible tissue, rapid procurement, and chondrogenic potential ( Zhang et al, 2019 ; De Francesco et al, 2021 ). Ovine aMSCs proliferated faster than bMSCs but expressed lower cartilage-specific gene levels for collagen II, SOX9, and aggrecan in vitro , despite both MSC types performing similarly in osteoarthritic ovine knees ( Ude et al, 2014 ).…”