Xiangdong Cui

The Viability of Autologous Fat Grafts Harvested With the LipiVage System : A Comparative Study

This study evaluates the viability of adipose aspirates harvested with the LipiVage system (Genesis Biosystems Inc, Lewisville, TX), a newly developed fat harvesting device, and determines a potentially preferred method for possible large-quantity fat graft harvesting. Adipose aspirates were harvested with the LipiVage system from the abdomen of 16 female patients (group 1, n = 8) according to the instruction by the manufacturer and with conventional liposuction (group 2, n = 8). Samples from conventional liposuction were spun at 50 g for 10 minutes and the resulting middle layer of fat was collected. All fat graft samples were evaluated with trypan blue vital staining for viable adipocyte count, glycerol-3-phosphatase dehydrogenase (G3PDH) assay for intracellular enzyme activity, and histology. In this study, group 1 had significantly higher viable adipocyte count than group 2 had (3.7 ± 0.64 versus 2.37 ± 0.56 × 106 /mL, P = 0.0021). G3PDH assay showed a marked increase of intracellular enzyme activity in group 1 compared with in group 2 (0.61 ± 0.10 versus 0.34 ± 0.13 U/mL, P = 0.00045). Histology revealed normal structures of fragmental fatty tissues in both groups. While adipose aspirates by both modalities maintain normal structure, the LipiVage system yields a greater number of viable adipocytes and sustains a higher level of intracellular enzyme activity within fat grafts and can potentially be a preferred method of choice for large-quantity fat graft harvesting.

Long-Term Preservation of Adipose Aspirates After Conventional Lipoplasty

BACKGROUND Optimal cryopreservation permits the long-term storage of living cells or tissues that may have potential clinical applications. Unfortunately, there are no successful studies on the long-term preservation of adipose aspirates for possible autologous fat grafting. OBJECTIVE The purpose of the current study was (1) to test our hypothesis that adipose aspirates obtained from conventional lipoplasty could be preserved and stored at low temperature (below -85 degrees C) by means of an optimal cryopreservation technique and (2) to develop a novel approach to effectively preserve adipose aspirates for future applications. METHODS The middle layer of adipose aspirates obtained from conventional lipoplasty was collected after centrifugation and each specimen was then randomized into 3 groups: the control group, fresh adipose aspirates without preservation; experimental group 1, simple cryopreservation with liquid nitrogen only; and experimental group 2, optimal cryopreservation with cryoprotective agents consisting of a combination of dimethyl sulfoxide (DMSO) and trehalose. Cryopreservation of adipose aspirates was conducted with controlled slow cooling and fast rewarming rates. Fresh or cryopreserved adipose aspirates in each group were evaluated by viable adipocyte counts, glycerol-3-phosphate dehydrogenase (G3PDH) assay, and routine histology. RESULTS Significantly more viable adipocytes and better cellular function of adipose aspirates were found in the experimental group 2 compared to the results in the experimental group 1. CONCLUSIONS Our results indicated that an optimal cryopreservation approach that utilizes a combination of DMSO and trehalose as cryoprotective agents appears to provide good long-term preservation of adipose aspirates obtained from conventional lipoplasty, albeit not as ideal as fresh specimens. An in vivo study will be conducted to confirm the results from our present in vitro study.

Cryopreservation of Adipose Tissues: The Role of Trehalose

BACKGROUND Several studies have shown that one of the sugars, trehalose, can improve tissue survival after cryopreservation when combined with other cryoprotective agents, and thus may possibly be used in cryopreservation of adipose tissues that have been found more resistant to injury after freezing. OBJECTIVES The purpose of this study was to test our hypothesis that lipoplasty-derived adipose aspirates could be effectively cryopreserved by adding trehalose as the sole cryoprotective agent (CPA), and to develop a practical technique to effectively preserve adipose tissues for future applications. METHODS The middle layer of adipose aspirates obtained from conventional lipoplasty was collected after centrifugation and each specimen was randomized into 3 groups: the control group, fresh adipose aspirates without preservation; the simple cryopreservation group (no CPA); and the optimal cryopreservation group (with trehalose as a CPA). Cryopreservation of adipose aspirates was conducted with controlled slow cooling and fast rewarming rates. Fresh or cryopreserved adipose aspirates in each group were evaluated by viable adipocyte counts, glycerol-3-phosphate dehydrogenase (G3PDH) assay, and routine histology. RESULTS More viable adipocytes and better cellular function of adipose aspirates were found in the optimal cryopreservation group compared to the simple cryopreservation group, but these results were less ideal than results from the control group. CONCLUSIONS An optimal cryopreservation method using trehalose as a CPA appears to provide better long-term preservation of adipose aspirates than a simple cryopreservation method. Further studies are needed to refine our method for cryopreservation with trehalose as a CPA and confirm our findings in vivo.

The fate of cryopreserved adipose aspirates after in vivo transplantation

BACKGROUND Successful long-term preservation of adipose tissues may have an important impact on future clinical application of autologous fat transplantation. Our group has recently developed an optimal cryopreservation method for possible long-term preservation of adipose aspirates. OBJECTIVE The purpose of this study was to evaluate the fate of previously cryopreserved adipose aspirates after in vivo administration in an established nude mouse model. METHODS Adipose aspirates were collected from a cosmetic lipoplasty of the patients abdomen after centrifugation. In the fresh control group (n = 20), fresh adipose aspirates were injected into the posterior scalp of a nude mouse. In the optimal cryopreservation group (n = 20), adipose aspirates after the optimal cryopreservation were injected. In the simple cryopreservation group (n = 20), adipose aspirates after the simple cryopreservation were injected. All animals in each group were observed for gross appearance of maintained fat grafts over their posterior scalps for up to 16 weeks. The final volume and weight of maintained fat grafts and their histology were evaluated at the end of the study. RESULTS More maintained volume, weight, and fatty tissue structure of injected free grafts were found in the optimal cryopreservation group compared with the simple cryopreservation group, but the results were still less satisfactory than those in the fresh control group. CONCLUSIONS Based on this in vivo study, we believe that an optimal cryopreservation method developed in our laboratory provides reasonably good long-term preservation of adipose aspirates. However, further studies may still be warranted to refine our method for optimal cryopreservation of adipose tissues.

Cryopreservation and Microsurgical Implantation of Rabbit Carotid Arteries

Use of cryopreserved small-diameter elastic arterial allografts for an arterial bypass procedure has been suggested. But, the long-term patency of the cryopreserved arteries in vivo has not been 100%. Thirty New Zealand White rabbits were used in this study. The experimental arterial segments were cooled and cryopreserved in liquid nitrogen, and warmed with a precooled water jacket apparatus. The frozen/thawed autologous carotid artery was attached end to end by anastomosis with microsurgery. Patency and structural characteristics of implanted arteries were periodically assessed for 12 months using duplex/Doppler ultrasound. Histopathological analysis was performed after 1 year of observation. The results showed that (1) the thawing device we designed was useful in preventing fractures during warming processes; (2) the immediate patency was 100% following autograft implantation; (3) after 4 months, blood flow was not observed via ultrasonography in two cryopreserved arteries and in one control group arter...