To our knowledge, this is the first reported clinical use of DEP processing of SVF cell therapy in a human. Contrary to our original hypothesis, a significant improvement in clinical outcomes was appreciated with the experimental procedure of the study. Positive benefit was noted in immediate post-surgical healing parameters (Figures , , , and ). Of particular note: post-surgical skin eruptions and ulcerations occurred only on the control hand (Figure ). Location of skin breaks were highly correlated to RBX filter images showing vascular injection and dilation occurring towards the center of the hand (Figure ). This is consistent with other fat transfers we have performed with and without SVF supplementation in the past (Figure ). Interestingly, the experimentally treated hand sustained vascular changes as well, but to a smaller surface area, yet did not have any skin breaks or ulcerations despite receiving equal volumes of enriched fat graft. Moreover, the side with DEP purified SVF exhibited superior engraftment especially in the largest volume treatment region, the thenar web space, which is a common site of failure (Figure lower panels).
Figure 15 69-year-old female status post hand lipotransfer post operative day 7 with DEP treated (left pane) versus control (right pane). Note eruptions, ulcers and skin breaks (red circles) which occurred exclusively on the control hand. Swelling is more prominent (more ...)
Figure 16 69-year-old female status post hand lipotransfer procedure post operative day 4. Spectral imaging of hands with RBX mode showing regions of inflamed skin (green circles) with DEP (left panel) versus control (right panel). Regions of ulceration and skin (more ...)
A cohort of hands in women aged 60-73-years-old within 1 week post standard lipotransfer. The typical complication revealing ulceration and eruptions (green circle) within the center of the hand.
Figure 18 69-year-old female status post hand lipotransfer 3 months post surgery. Before and after images of hands treated with standard fat transfer (right hand) versus DEP purified SVF (left side). Note early loss of engraftment noted in control hand thenar web (more ...)
It is not entirely clear why a clinical difference occurred, though great efforts were taken to control for similar conditions (i.e. equivalent cell handling and DEP media exposure for both interventions). Measures were also taken to select a patient with similar appearing hands and endogenous vascularization confirmed by arterial Doppler flow studies prior to therapy. Both interventions from a clinical perspective, however, did yield comparable appearing aesthetic results, though the skin consistency of the DEP-SVF treated hand was palpably more dense with normal turgor, whereas the control hand retained a parchment like quality to the skin (Figure ). Further differences in deeper subdermal consistency were also appreciated on ultrasound in the control hand, such that oil cysts (an early sign of graft failure) were appreciated in greater number than the DEP-SVF treated hand (Figures , , and ).
Ultrasound image of left hand (DEP-SVF treated) saggital view of thenar web space of a 69-year-old female 3 months post lipotransfer.
Ultrasound image of left hand (DEP-SVF treated) coronal view of thenar web space of a 69-year-old female 3 months post lipotransfer.
Ultrasound image of right hand (control) saggital view of thenar web space of a 69-year-old female 3 months post lipotransfer. Oil cysts seen in superficial dermis (red circle).
Ultrasound image of right hand (DEP-SVF treated) coronal view of thenar web space in a 69-year-old female 3 months post lipotransfer. Oil cyst seen in deeper dermis (red circle).
Unexpectedly the patient sustained a minor decrease in extension capability at the wrist and digits in the control hand. Though minor, any functional deficit can have an exponential effect on an already compromised dexterity, due to concomitant disease (i.e. arthritic joint disease and tendon contractures). We have speculated in 30
years of performing standard lipotransfer of the hand that, in select cases, cellular debris may contribute to surrounding fibrillary tangles (Figure ) and eventual fibrosis (Figure ) surrounding tendon sheaths, which impairs normal free movement of the hand. Perhaps this complication may be related to cellular focusing of SVF cells (Figure ) and the elimination of cellular debris (Figures , and ) and inflammatory mediators, which recruit adipose lipophages and other inhibitory cells to exacerbate endogenous underlying disease (i.e. arthritis) [5
]. This is suggested indirectly by the higher thermocouple readings (Figure ) and other surrogate markers for inflammation (i.e. finger circumference, pain and decreased mobility) seen in the control hand. However, exposure to a DEP field in and of itself could also play a beneficial role by inducing cell cycle activation of “pre-viable” or quiescent (G0
) cells, which in a typical transfer provide no immediate healing functions. Further studies to disentangle these issues in addition to randomized control trial studies with the DEP device are currently being conducted at our centers.
Figure 23 Microscopic image (40X, H and E staining) of fibrillary tangles of cellular debris and adipocyte matrix biopsied from a hand 3 weeks post standard fat transfer. (Previous patient not part of this study.) Note mast cells (green arrows) surrounding cellular (more ...)
Microscopic image (40X, H and E staining) of engrafted fat with dense fibrosis (white arrow) surrounding nascent fat globules (black arrow) at 6 months post standard lipotransfer. (Previous patient not part of this study).
Figure 25 40x microscopic image of SVF before (left pane) and after (middle pane) DEP isolation. (Smaller dark particles in middle panel are unsettled defocused SVF cells.) DEP isolated cells directly plated to Matrigel coated culture dish (right panel) without (more ...)
Though current beneficial implications of accelerated healing and improved engraftment are promising, clinical DEP presents even greater future implications for the field of regenerative medicine and cell therapy. FDEP can be modulated in direction (i.e. capture vs. repulsion) and magnitude. The methodology is also versatile enough to function at the nano- , micro- and macro- level. This affords the ability to “tune-in” or “tune-out” specific cell types from the heterogenous composition of SVF, which is unprecedented and represents the development of a second generation tool for regenerative medicine.
A device, such as the one used in this study, could be used to economically select or subtract cell types to more precisely define and refine cellular therapies. For example, breast augmentation using autologous SVF enriched adipose tissue has progressed with clinical results which continue to improve [22
], but safety issues such as calcification artifacts interfering with mammogram screening and the long-term risks of tumorgenesis have been raised [27
]. Additionally, recent epidemiologic data on prosthetic breast implants suggest foreign bodies within the breast space may be related to anaplastic large cell lymphoma (ALCL) as well [28
]. Clinical DEP could provide a safer breast fat graft by removal of osteogenic (calcification forming) precursors [29
] or CD-30 (ALCL associated) lymphocytes, which coincidentally can occur in high abundance as a contaminant in SVF (unpublished findings). Furthermore, DEP is also capable of detecting high nuclear to cytoplasmic ratio cells and extremely small charged particles, affording the possibility of “filtering” any graft free of cancer cells [30
] or bacteria [32
]. DEP can even select based on cell cycle status, opening the further possibility of improving cell therapy transplantation rates by transferring only actively dividing cells [33
Adipose SVF and ADSC have also found use in sports medicine, orthopedics and rehabilitation therapy. One particular treatment showing strong demand is treatment of damaged or worn cartilage with SVF/ADSC. There are conflicting reports of efficacy for this indication [34
]. Inadvertent simultaneous transplantation of pre-committed adipose precursor cells within the SVF into articular spaces could have poor long-term consequences. Recurrent damage of engrafted ectopic fat on articular surfaces release lipid and long chain fatty acids. This can be converted into prostaglandins and other mediators of inflammation (i.e. adipokines), thus accelerating native cartilage degeneration [35
]. Joint space injections with purified chondrocyte destined cells, minus adipogenic precursors, would be preferable to a random heterogeneous approach currently in use and presents yet another example of how clinical DEP could be applied.
In more recent developments, popular media reports of regenerative medicine utilization by prominent athletes (i.e. Peyton Manning, Chad Ochocinco and Terrell Owens) have created a glamorizing effect to the field. While these famous cases of stem cell therapy are helpful in raising awareness, disproportionate attention to the promise, but not the potential consequences, leave serious concerns of the public being unfairly biased and indirectly counseled by dominating modern media and content [36
]. Though it is not the intention of this paper to morally assail any practitioner or patient, we believe the growing demand for cellular therapies is reaching critical mass and signifies the necessity of a clinical paradigm shift from a focus of efficacy, to one of safety. To this end, all second generation separation technologies, especially DEP, should be investigated with a greater sense of urgency to address the growing immediate need for safety.