The Impact of Harvesting Systems and Donor Characteristics on Viability of Nucleated Cells in Adipose Tissue: A First Step Towards a Manufacturing Process

Autologous Adipose-Derived Tissue Stromal Vascular Fraction (AD-tSVF) for Knee Osteoarthritis

Adipose tissue contains adult mesenchymal stem cells that may modulate the metabolism when applied to other tissues. Stromal vascular fraction (SVF) can be isolated from adipose tissue mechanically and/or enzymatically. SVF was recently used to decrease the pain and improve the function of knee osteoarthritis (OA) patients. Primary and/or secondary OA causes inflammation and degeneration in joints, and regenerative approaches that may modify the natural course of the disease are limited. SVF may modulate inflammation and initiate regeneration in joint tissues by initiating a paracrine effect. Chemokines released from SVF may slow down degeneration and stimulate regeneration in joints. In this review, we overviewed articular joint cartilage structures and functions, OA, and macro-, micro-, and nano-fat isolation techniques. Mechanic and enzymatic SVF processing techniques were summarized. Clinical outcomes of adipose tissue derived tissue SVF (AD-tSVF) were evaluated. Medical devices that can mechanically isolate AD-tSVF were listed, and publications referring to such devices were summarized. Recent review manuscripts were also systematically evaluated and included. Transferring adipose tissues and cells has its roots in plastic, reconstructive, and aesthetic surgery. Micro- and nano-fat is also transferred to other organs and tissues to stimulate regeneration as it contains regenerative cells. Minimal manipulation of the adipose tissue is recently preferred to isolate the regenerative cells without disrupting them from their natural environment. The number of patients in the follow-up studies are recently increasing. The duration of follow up is also increasing with favorable outcomes from the short- to mid-term. There are however variations for mean age and the severity of knee OA patients between studies. Positive outcomes are related to the higher number of cells in the AD-tSVF. Repetition of injections and concomitant treatments such as combining the AD-tSVF with platelet rich plasma or hyaluronan are not solidified. Good results were obtained when combined with arthroscopic debridement and micro- or nano-fracture techniques for small-sized cartilage defects. The optimum pressure applied to the tissues and cells during filtration and purification of the AD-tSVF is not specified yet. Quantitative monitoring of articular joint cartilage regeneration by ultrasound, MR, and synovial fluid analysis as well as with second-look arthroscopy could improve our current knowledge on AD-tSVF treatment in knee OA. AD-tSVF isolation techniques and technologies have the potential to improve knee OA treatment. The duration of centrifugation, filtration, washing, and purification should however be standardized. Using gravity-only for isolation and filtration could be a reasonable approach to avoid possible complications of other methodologies.

Optimization of the Soft Tissue Envelope of the Nose in Rhinoplasty Utilizing Fat Transfer Combined with Platelet-Rich Fibrin

A thin or damaged skin soft tissue envelope may cause concerns in primary and secondary rhinoplasty. During postoperative healing, unpredictable scarring and contraction may occur and lead to significant aesthetic and trophic sequelae. Besides a meticulous surgical technique, there are no reliable techniques to prevent long-term skin damage and shrinkage. Fat transfer with addition of platelet-rich fibrin (PRF) harbors the possibility of local soft tissue regeneration and skin rejuvenation through growth factors and mesenchymal stem cells. It may also facilitate the creation of a thin fat layer on the dorsum to prevent shrink-wrap forces and conceal small irregularities. The goal is to provide evidence for the feasibility, durability, and beneficial effect of diced macrofat transfer bonded with PRF on the nasal dorsum. We present the technique of fat transfer conjugated with PRF as a nasal dorsal graft. Clinical endpoints were the prevention of trophic disturbances and atrophy at a 1-year postoperative follow-up. We present the skin mobility test as a clinical indicator of a healthy soft tissue envelope. The presented case series consists of 107 rhinoplasties. Fat was harvested in the umbilical or costal region. PRF was created by centrifugation of autologous whole blood samples. Macrofat was diced, cleaned, and bonded with PRF. The compound transplants were transferred to the nasal dorsum. There were no perioperative complications or wound-healing issues. Mean follow-up was 14 months. Clinical inspection showed good skin quality and no signs of shrinkage, marked scarring, or color changes with positive skin mobility test in all patients. Survival of fat was confirmed by ultrasonography and magnetic resonance imaging. Diced macrofat transfer in conjunction with PRF to the nasal dorsum is a feasible and safe method. A beneficial effect on the soft tissue envelope is demonstrated as well as the prevention of shrink-wrap forces.

Influence of donor age on the differentiation and division capacity of human adipose-derived stem cells

BACKGROUND

Human adipose-derived stromal/stem cells (hASCs) are one of the most useful types of mesenchymal stromal/stem cells, which are adult multipotent cells with great therapeutic potential for the treatment of several diseases. However, for successful clinical application, it is critical that high-quality cells can be obtained. Diverse factors seem to be able to influence cell quality and performance, especially factors related to donors’ intrinsic characteristics, such as age. Nevertheless, there is no consensus regarding this characteristic, and there is conflicting information in the literature.

AIM

To investigate the growth kinetics and differentiation potential of adipose-derived stem cells isolated from the lipoaspirates of elderly and young donors.

METHODS

hASCs were harvested from liposuctioned adipose tissue obtained from female donors (aged 20-70 years). Cells were distributed into two groups according to age range: old hASCs (oASCs, ≥ 55 years, n = 9) and young hASCs (yASCs, ≤ 35 years, n = 9). For each group, immunophenotypic characterization was performed by flow cytometry. Population doubling time was assessed over seven days. For adipogenic potential evaluation, lipid deposits were assessed after 7 d, 14 d and 21 d of adipogenic induction. Osteogenic potential was verified by analyzing cell mineralization after 14 d, 21 d and 28 d of osteogenic induction. mRNA expression of PPARγ2, CEBPA and Runx2 were detected by quantitative reverse transcription polymerase chain reaction.

RESULTS

hASCs were successfully obtained, cultured, and grouped according to their age: yASCs (26.33 ± 4.66 years old) and oASCs (64.78 ± 4.58 years old). After maintenance of the cells in culture, there were no differences in morphology between cells from the young and old donors. Additionally, both groups showed classical immunophenotypic characteristics of mesenchymal stem/stromal cells. The average doubling time indicated that yASCs (4.09 ± 0.94 d) did not significantly differ from oASCs (4.19 ± 1.29 d). Concerning differentiation potential, after adipogenic and osteogenic induction, yASCs and oASCs were able to differentiate to greater levels than the noninduced control cells. However, no differences were found in the differentiation efficiency of yASCs and oASCs in adipogenesis or osteogenesis. Additionally, the mRNA expression of PPARγ2, CEBPA and Runx2 were similar in yASCs and oASCs.

CONCLUSION

Our findings suggest that age does not seem to significantly affect the cell division or adipogenic or osteogenic differentiation ability of adipose-derived stem cells isolated from lipoaspirates.