Cryopreserved Fat Research Articles

Exosomes Derived from Human Adipose-Derived Stem Cells Cannot Distinctively Promote Graft Survival in Cryopreservation Fat Grafting.

Cryopreserved fat has limited clinical applications due to its rapid absorption, high degree of fibrosis, and risk of complications after grafting. Many studies have verified that Adipose-derived mesenchymal stem cell-derived exosomes (ADSC-Exos) can improve fresh fat graft survival. This study assessed whether ADSC-Exos could improve the survival of cryopreserved fat grafts. Exosomes were isolated from human ADSCs were subcutaneously engrafted with adipose tissues stored under different conditions (fresh; cryopreserved for 1 month) into the backs of BALB/c nude mice (n = 24), and exosomes or PBS were administered weekly. Grafts were harvested at 1, 2, 4, and 8 weeks, and fat retention rate, histologic, and immunohistochemical analyses were conducted. At 1, 2, and 4 weeks after the transfer, cryopreserved fat grafts in groups of exosome-treated showed better fat integrity, fewer oil cysts, and reduced fibrosis. Further investigations of macrophage infiltration and neovascularization revealed that those exosomes increased the number of M2 macrophages at 2 and 4 weeks (p<0.05), but had limited impact on vascularization (p>0.05). It's important to note that no significant differences (p>0.05) were observed between the two groups in both histological and immunohistochemical evaluations at 8 weeks post-transplantation. This study suggests that ADSC-Exos could improve the survival of cryopreserved fat grafts in the short term (within 4 weeks), but the overall improvement was poor (after 8 weeks). This suggests that the utility of using ADSC-Exos to treat cryopreserved adipose tissue grafts is limited. This journal requires that authors assign a level of evidence to each submission to which Evidence-Based Medicine rankings are applicable. This excludes Review Articles, Book Reviews, and manuscripts that concern Basic Science, Animal Studies, Cadaver Studies, and Experimental Studies. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Sequential Grafting of Fresh and Cryopreserved Fat After Mechanical Processing is a Safe and Effective Facial Rejuvenation Strategy.

The survival rate of fat transplants is variable and consequently multiple operations are often required to achieve satisfactory results. Fat cryopreservation technology is a good solution to this problem. At present, cryopreservation of fats needs to be added with cryopreservation agents, which brings unsafety and operational complexity to clinical applications. An efficient and safe strategy for fat cryopreservation must be developed. A retrospective study was performed of all patients who underwent facial fat grafting and agreed to have their fat tissue cryopreserved from January 2018 to May 2021. Fat samples were physically processed to obtain SVF-gel, which was cryopreserved at - 20°C for up to 3 months and injected after thawing. Images acquired by pre- and post-operative 3D scanning of the temporal region were compared to evaluate the retention rate of transplanted cryopreserved SVF-gel. No patients experienced serious complications after receiving cryopreserved fat transplantation. The retention rate of cryopreserved SVF-gel was 46.3 ± 7.7% at 3 months and 43.1 ± 7.2% at 6 months after transplantation. The swelling duration was significantly shorter after cryopreserved SVF-gel transplantation (5.5 ± 0.8 days) than after fresh fat transplantation (7.5 ± 0.7 days) (p &lt; .031). Injection of cryopreserved SVF-gel achieves good retention rate for facial rejuvenation and has few side effects. Cryopreservation of SVF-gel is a safe and effective strategy for serial fat grafting for facial rejuvenation. This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

The effect of glycerol as a cryoprotective agent in the cryopreservation of adipose tissue

BackgroundLong-term preservation of adipose tissue is crucial for clinical applications. Researchers should consider both efficiency and biosafety when choosing a cryoprotective agent (CPA) for adipose tissue preservation. Glycerol has been applied as a nontoxic CPA for multiple tissues but not adipose tissue. We aimed to evaluate the efficacy of glycerol as a CPA for adipose tissue cryopreservation.MethodsFresh human adipose tissues were obtained from patients who underwent liposuction and divided into 1 mL samples. Each sample was randomly mixed with 1 mL of CPA: 60–100% glycerol, 0.25 mol/L trehalose or DMSO + FBS and cryopreserved in − 196 °C liquid nitrogen for one month. After thawing and elution, the tissues were immediately evaluated for activity and structural integrity in vitro. Then, 0.2 mL of each sample was transplanted subdermally to the nude mouse dorsum and harvested after one month for histological examination to assess the effect of the cryopreserved fat in transplantation.ResultsAfter cryopreservation, the samples treated with DMSO + FBS, trehalose, 60% and 70% glycerol had a more integrated structure than the samples in other groups. Tissues preserved with 70% glycerol had the highest G3PDH activity of 24.41 ± 0.70, comparable to 24.76 ± 0.48 in fresh tissue (p > 0.05). Adipose-derived stem cells (ASC) viability, proliferation and differentiation capability were also better preserved in 70% glycerol group. In vivo analysis showed that tissue preserved with 70% glycerol had a retention rate of 52.37 ± 7.53%, significantly higher than other groups. Histological observation demonstrated better structural integrity and viability in 70% glycerol group. Compared to the DMSO + FBS and trehalose groups, the glycerol groups showed lower tissue inflammation.ConclusionGlycerol (70%) is efficient in adipose tissue cryopreservation. Glycerol-based CPAs, which are nontoxic and show biosafety, are a promising solution for clinical tissue cryopreservation.

Cryopreservation of adipose tissue with and without cryoprotective agent addition for breast lipofilling: A cytological and histological study

In the second reconstructive phase of the breast after mastectomy, lipofilling is often necessary. Currently, lipofilling occurs immediately after autologous adipose tissue harvesting procedure, but most of the patients, usually, require multiple sessions to obtain a satisfactory result. Therefore, the need of repeated surgical harvesting outputs implies high risk of patients’ morbidity and discomfort as well as increasing medical time and costs. The aim of our pilot study was to find out a feasible method to cryopreserve adipose tissue, in order to avoid reiterated liposuctions.Lipoaspirates samples have been harvested from 10 women and preserved by three methods: (1) the first one, using 10% Me2SO and 20% human albumin from human plasma as cryoprotective agents; (2) the second one, adding 5% Me2SO as cryoprotective agent; 3) the last one, without any cryoprotective agent. Fresh and cryopreserved fat samples, obtained through the aforementioned processes, have been analyzed ex vivo. The efficiency of the cryopreservation methods used was determined by adipocyte viability and the expression of adipocytes surface markers.Lipoaspirates stored at −196 °C for 3 months, after thawing, retained comparable adipocyte viability and histology to fresh tissue and no significant differences were found between the three methods used. Although the current results, differences between the methodologies in terms of viability may not become evident until breast lipofilling using frozen-thawed cryopreserved tissue.

Periorbital lipogranuloma after facial injection of autologous fat: A retrospective study of 18 cases.

To investigate the clinical features of patients who develop periorbital lipogranuloma after injection of autologous fat. This retrospective case series included 18 patients who developed a periorbital mass or swelling after undergoing injection of autologous fat for facial augmentation. The patients' medical records were reviewed for clinical history, radiologic findings, and treatment outcomes. All patients were women aged 24 to 50 years (mean, 31.6 years). Five patients (27.8%) involved both orbits. Presenting eye symptoms were a palpable mass (61.1%), eyelid swelling (44.4%), and ptosis (16.7%). The interval between the final injection and onset of eye symptoms ranged from 1 to 36 months (mean, 11.5 months). Thirteen patients underwent radiologic imaging. Fifteen patients received only one injection of autologous fat and three received two injections with the cryopreserved fat used in the second injection. Surgical excision was performed in 12 patients to remove the mass and identify the pathologic abnormalities. No recurrence was found during 1 year of follow-up. Two of the six patients who had refused treatment showed spontaneous resolution at the 6-month visit. Periorbital lipogranuloma after facial injection of autologous fat should be considered as a specific orbital disease entity for which MRI is an effective examination method. Surgery is warranted for this condition when conservative treatment is ineffective.

Comparisons between fresh and cryopreserved fat injections in facial lipofilling.

BackgroundAutologous fat is considered an ideal filler material, and the use of cryopreserved fat grafts is promising in terms of flexibility and efficiency. Therefore, cryopreserved fat grafts have become more common in recent years; however, their complications require further consideration.MethodsWe evaluated 53 patients who underwent facial lipofilling at our institution to confirm the clinical usefulness and safety of cryopreserved fat. Fresh fat injections with or without cryopreserved fat were administered. At one or more sites, 22 patients had a single fresh fat injection, four patients had two or more fresh fat injections, 16 patients had one fresh fat injection followed by one cryopreserved fat injection, six patients had one fresh fat injection followed by two cryopreserved fat injections, and five patients had two fresh fat injections and one or more cryopreserved fat injections.ResultsIn total, 281 sets of injection procedures were performed at various sites, of which 170 involved one fresh fat injection, 89 involved one fresh fat injection and one cryopreserved fat injection, and 11 involved one fresh fat injection and two cryopreserved fat injections. One patient experienced self-resolving inflammation as a complication after the second injection in the right cheek. No statistically significant differences were found between the fresh and cryopreserved fat injections.ConclusionWe suggest that cryopreserved fat is a useful and safe resource for multiple fat injections, with advantages including aseptic fat handling and the delicacy of the technique.

Mechanical process prior to cryopreservation of lipoaspirates maintains extracellular matrix integrity and cell viability: evaluation of the retention and regenerative potential of cryopreserved fat-derived product after fat grafting

BackgroundCryopreservation of fat grafts facilitates reinjection for later use. However, low temperature and thawing can disrupt tissues and cause lipid leakage, which raises safety concerns. Here, we compared the cryopreservation potential of stromal vascular fraction (SVF) gel processed from lipoaspirate with that of fat.MethodsHuman SVF gel and fat were cryopreserved at − 20 °C without cryoprotectant for 1 month. Fresh SVF gel and fat were used as controls. Tissue viability, adipose-derived stem cell (ASC) function, and the extracellular content were evaluated. At 3 months after transplanting the specimens to immunocompromised mice subcutaneously, the grafts were examined for retention, tissue engraftment, and inflammatory levels. The regenerative effect of cryopreserved SVF gel was evaluated in a murine ischemic wound healing model.ResultsAt 1 month, the cell death rate in the SVF gel group was 36 ± 2%. The survived ASCs not only could be isolated via explant culture but also preserved colony-forming and differentiation. However, prolonged cryopreservation exacerbated apoptosis. Assessment of recovered tissues showed that the morphology, cell viability, and extracellular protein enrichment were better in SVF gel-preserved tissues than in frozen fat. At 3 months after lipotransfer, the retention ability of 1-month cryopreserved fat was 41.1 ± 9% compared to that of 1-month cryopreserved SVF gel. Immunostaining results showed that adipose tissue regeneration and integrity in the 1-month cryopreserved SVF gel group were superior to those of the cryopreserved fat group. The cryopreserved SVF gel also accelerated healing of the ischemic wound, compared with cryopreserved fat.ConclusionCryopreserved SVF gel maintained tissue integrity and cell viability and resulted in a better long-term retention rate than that of cryopreserved fat. Cryopreserved SVF gel also showed superior regenerative potential and improved ischemic wound healing.

Effects of Frozen Stromal Vascular Fraction on the Survival of Cryopreserved Fat Tissue

BackgroundNowadays, the use of cryopreserved fat tissue for soft tissue augmentation is common, except for its unpredictable fat graft absorption, and the toxicity of the cryoprotective agent remains a limitation. In this study, the effects of freezing stored fat tissue without a cryoprotector, and the addition of the stromal vascular fraction (SVF) on the survival of cryopreserved transplants was studied.MethodsLipoaspirates from six donors were processed and cryopreserved at − 20 °C, − 80 °C and − 196 °C, respectively. The authors evaluated the lipoaspirates in vitro, on the basis of fat tissue and SVF viability after cryopreservation. In vivo fat grafting was performed in nude mice. Six trenches were injected on the backs of mice. Cryopreserved tissues (− 20 °C, − 80 °C and − 196 °C) were injected on the right side, and the other side received the SVF combination. At 4 and 8 weeks after transplantation, the authors examined the weight, volume and morphology of the tissue and analyzed histochemical staining and immunohistochemistry (i.e., DIL, CD31 and VWF) to evaluate the survival of the fat grafts.ResultsAfter cryopreservation without the cryoprotective agent, adipose tissue maintained its morphology better in − 80 °C than − 20 °C and − 196 °C. SVF cells can retain their adhesive and proliferative properties after cryopreservation. Although cryopreservation caused damage to fat tissue, all explants showed intact adipocytes and vascular ingrowth. Most of all, the − 80 °C group had less graft resorption and fibrosis than the other temperature groups. There was increased survival of fat grafts in the SVF group compared with the control group.ConclusionIn this study, the authors demonstrated that the storage temperature of − 80 °C was promising for 3 months of adipose tissue cryopreservation without a cryoprotective agent, and SVF could increase the survival rate of cryopreserved fat tissue.No Level AssignedThis journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266.

Isolation of Adipose-Derived Stem/Stromal Cells from Cryopreserved Fat Tissue and Transplantation into Rats with Spinal Cord Injury.

Adipose tissue contains multipotent cells known as adipose-derived stem/stromal cells (ASCs), which have therapeutic potential for various diseases. Although the demand for adipose tissue for research use remains high, no adipose tissue bank exists. In this study, we attempted to isolate ASCs from cryopreserved adipose tissue with the aim of developing a banking system. ASCs were isolated from fresh and cryopreserved adipose tissue of rats and compared for proliferation (doubling time), differentiation capability (adipocytes), and cytokine (hepatocyte growth factor and vascular endothelial growth factor) secretion. Finally, ASCs (2.5 × 106) were intravenously infused into rats with spinal cord injury, after which hindlimb motor function was evaluated. Isolation and culture of ASCs from cryopreserved adipose tissue were possible, and their characteristics were not significantly different from those of fresh tissue. Transplantation of ASCs derived from cryopreserved tissue significantly promoted restoration of hindlimb movement function in injured model rats. These results indicate that cryopreservation of adipose tissue may be an option for clinical application.

Serial Injections of Cryopreserved Fat at -196°C for Tissue Rejuvenation, Scar Treatment, and Volume Augmentation.

Background:Fat grafting has become popular since the first report of structural fat grafting in 2001. Fat grafting is effective not only for volume augmentation but also for tissue revitalization. However, fat harvesting is necessary before fat grafting can be performed. Therefore, the performance of serial fat injections is very challenging when treating such patients.Methods:From August 2015 to March 2017, we investigated 219 patients who underwent fat grafting using the fat that had already been cryopreserved at −196°C.Results:Follow-up ranged from 3 months to 2 years. No complications occurred, and all outcomes were satisfactory. Three representative cases were also reviewed.Conclusions:The cryopreserved fat at −196°C could be served as a useful method for serial fat grafting for clinical use; however, further research involving longer follow-up and pathological findings are needed.

Facial recontouring with autologous cryopreserved fat graft

Background: Autologous fat graft is a well established technique for soft tissue augmentation and the most significant drawback remains the unpredictability of the absorption rate and the possible repeating fat harvest procedures. In our basic study, we found evidence to support that fat cryopreservation is a practical method of storing fat tissue and several anecdotal clinical experiences suggest its clinical efficacy. Methods: Thirty two patients who received autologous cryopreserved fat grafts for facial deficiencies were retrospectively reviewed. Autologous cryopreserved fat grafts were transplanted for “touch up” or augmentation of other soft tissue deficiencies at least three months after fresh fat grafting, The patients' satisfaction was evaluated by a study-specific questionnaire. Results: 84 autologous fresh fat graft and 178 autologous cryopreserved fat graft procedures for the face were performed in 32 patients. There was no infection, skin retraction, fibrosis or necrosis identified except one patient complained of lump formation in the left upper lid (1/178, 0.6%). The self-assessment questionaaire revealed no statistical difference of effectiveness rating between the fresh and cryopreserved fat grafting results (mean± standard deviation: 8.64±1.09 vs 8.73±0.985; P > 0.05) but there was significant statistical difference of convenience rating between the fresh and cryopreserved fat grafting (mean± standard deviation: 2.68±1.07 vs 8.41±1.05; P Conclusions: Autologous cryopreserved fat graft is a safe, simple, and convenient technique to restore facial soft tissue defects with acceptable patient satisfaction rate. Clinical Question/Level of Evidence: Therapeutic, IV.

Discussion: Biological Properties and Therapeutic Value of Cryopreserved Fat Tissue.

Cork, Ireland From the Department of Plastic Surgery, University College Cork. Received for publication August 23, 2017; accepted August 28, 2017. Disclosure:The authors have no financial interest to declare in relation to the content of this Discussion or of the associated article. Anthony J. P. Clover, M.D., Department of Plastic Surgery, Cork University Hospital, Cork, Ireland, [email protected]

Effects of increased proliferation of human adipose tissue-derived mesenchymal stem cells by sphingosylphosphorylcholine on the survival of cryopreserved fat grafts

The use of cryopreserved adipose tissue for soft-tissue augmentation is common, but the unpredictability of fat graft viability remains a limitation. Human adipose-derived stem cells (hADSC) have been introduced to enhance viability and improve the survival of transplanted fat tissue. Sphingosylphosphorylcholine (SPC) is a bioactive lipid molecule involved in various cellular responses. SPC stimulates the proliferation of various cell types such as hADSC. We demonstrated the effects of hADSC and SPC on the survival of cryopreserved fat grafts in nude mice. The cryopreserved fat grafts were treated with hADSC or hADSC+SPC, and a normal saline (control) mixture in BALB/c male nude mice. We examined the weight and volume of the mice in each group (n=11) at 8 weeks after transplantation to evaluate the survival of the fat tissue. The hADSC group showed increased weight and volume compared with the control group. The hADSC+SPC group showed a higher survival rate in terms of weight and volume than the control or hADSC group. In addition, the hADSC+SPC treatment significantly increased the expression of angiogenic factors. These results suggest the potential clinical utility of hADSC+SPC.

Facial rejuvenation: Serial fat graft transfer

Autologous fat transfer is a century-old method for both aesthetic and reconstructive purposes. It is considered by many plastic surgeons the ideal body filler. The only disadvantage is its variable degree of resorption, which ranged from 45% to 80%. Various groups have studied the effects of cryo-preservation for fat storage, the advantage being that fat harvesting need only be performed once, and thereafter fat injections can be performed using stored fat as an outpatient service. This a clinical study carried out to test the aesthetic outcome of serial injection of the cryo-preserved fat cells for both aesthetic and reconstructive purposes. MethodsClinical evaluation was performed under standardized condition for serial lipofilling between October 2003 and May 2012, and 364 autologous fat transfers were performed in 104 patients ranging in age from 18 to 69years (mean age 34years). ResultsThe postoperative clinical results favored the use of serial fat transfer because the aesthetic and structural results were stable up to 90% of the initial volume more than a year after initial transfer. ConclusionOur data suggest that serial transfer of the cryo-preserved fat leads to better cosmetic results on the basis of outpatient service without increasing the financial burden for our patients.

Effects of human adipose-derived stem cells and stromal vascular fraction on cryopreserved fat transfer.

The use of cryopreserved adipose tissue for soft tissue augmentation is common, but unpredictability of fat graft viability remains a limitation. Adipose-derived stem cell (ADSC) and stromal vascular fraction (SVF) have been introduced to enhance viability and improve the survival of transplanted fat tissue. To investigate whether supplementation with ADSC or SVF improved the survival of cryopreserved fat grafts. The cryopreserved fat grafts were treated with ADSC, SVF, or normal saline in 30 six-week-old male nude mice to test whether ADSC and SVF could improve the survival of the transplanted fat tissue. The authors examined the weight, volume, and histological features of each group (n = 10) at 8 weeks after transplantation to evaluate the survival of the fat tissue. There was no difference between the control and SVF groups with respect to weight, volume, and histological findings. However, the ADSC group showed a significant increase in weight and volume compared with the control and SVF groups. Histological examination showed that the ADSC supplementation improved the quality of the transplanted fat grafts. Taken together, these results suggest a potential clinical utility of ADSC but no advantage of SVF in facilitating cryopreserved fat transfer.

Comparison of the viability of cryopreserved fat tissue in accordance with the thawing temperature.

BackgroundAdipose tissue damage of cryopreserved fat after autologous fat transfer is inevitable in several processes of re-transplantation. This study aims to compare and analyze the survivability of adipocytes after thawing fat cryopreserved at -20℃ by using thawing methods used in clinics.MethodsThe survival rates of adipocytes in the following thawing groups were measured: natural thawing at 25℃ for 15 minutes; natural thawing at 25℃ for 5 minutes, followed by rapid thawing at 37℃ in a water bath for 5 minutes; and rapid thawing at 37℃ for 10 minutes in a water bath. The survival rates of adipocytes were assessed by measuring the volume of the fat layer in the top layers separated after centrifugation, counting the number of live adipocytes after staining with trypan blue, and measuring the activity of mitochondria in the adipocytes.ResultsIn the group with rapid thawing for 10 minutes in a water bath, it was observed that the cell count of live adipocytes and the activity of the adipocyte mitochondria were significantly higher than in the other two groups (P<0.05). The volume of the fat layer separated by centrifugation was also measured to be higher, which was, however, not statistically significant.ConclusionsIt was shown that the survival rate of adipocytes was higher when the frozen fat tissue was thawed rapidly at 37℃. It can thus be concluded that if fats thawed with this method are re-transplanted, the survival rate of cryopreserved fats in transplantation will be improved, and thus, the effect of autologous fat transfer will increase.

Effects of Long-Term Cryopreservation on Fat Grafts: An Experimental Study

The main drawback of free fat injection is the unpredictable resorption of the grafted fat, the rate of which has been reported to be between 30% and 70%. The reasons for this variability include different donor site preparation techniques, harvesting methods, instruments, fat grafting and injection techniques, grafting intervals, and methods of analysis. These variations have made it difficult to compare studies [1-5]. The high and diverse absorption rates result in uncertain clinical outcomes, and absorption requires additional grafts, which mean repeated harvesting procedures. Repeated harvesting procedures can increase cost and surgical risks, as well as patient pain and discomfort. Thus, overcorrection and repeated injections are generally accepted solutions, although cryopreservation of the harvested fat has been attempted in a number of studies. However, the problems of resorption and unpredictable results are even greater with cryopreserved fat [5-7]. There is no universal agreement on the fate of the cryopreserved fat, and the survival of adipocytes preserved in a general freezer without a cryoprotective agent is still controversial. Hee Jong Lee, Eun Key Kim

Mixed Infection of an Atypical Mycobacterium and Aspergillus Following a Cryopreserved Fat Graft to a Face

We report a chronic infection of a patient who received a cryopreserved fat graft on her face. A 22-year-old female patient presented with multiple abscesses of her face. Four months previously, she received a second fat graft with the fat harvested at a previous surgery which was cryopreserved for 2 months. On examination, she had tender erythematous nodules on both cheeks. A computed tomography of her neck showed multiple peripheral enhancing nodular lesions. In an open pus fungus culture, Aspergillus fumigatus growth was observed. On the Mycobacterium Other Than Tuberculosis identification PCR, Mycobacterium fortuitum was found. She was treated with levofloxacin, clarithromycin, and minocycline for 11 months, and finally the symptoms subsided. To avoid infection after the fat graft, cryopreserved fat should not be used as a possible grafting material. In cases of persistent infection, or in cases of waxes and gains after drainage of pus and short-term antibiotics therapy, atypical Mycobacterium or Aspergillus should be suspected and a PCR for them should be carried out.

Facial Rejuvenation With Staged Injections of Cryopreserved Fat and Tissue Cocktail

Facial rejuvenation by autologous fat transfer is common in aesthetic plastic surgery. The main drawback is progressive resorption, requiring repeated harvesting and microfat grafting. The authors present a method for cryopreservation of excess harvested fat and tissue to enable subsequent use of previously harvested excess material. Fat grafts were harvested using a 50-mL syringe and a 3- or 4-mm cannula. A tissue "cocktail" composed of dermis, fascia, and fat was prepared from excised scar tissue, tissue from abdominoplasty, or tissue from reduction mammaplasty. Cocktail specimens were placed in sterile tubes, immersed in a liquid nitrogen tank (-196°C), and stored at -80°C. At 3- to 6-month intervals, repeated cryopreserved fat graft injections were performed. Patients were evaluated by comparing preoperative and postoperative photographs. Between 2000 and 2010, a total of 5199 cryopreserved fat or tissue injections were performed in 2439 consecutive patients (age range, 19-80 years). Nasolabial folds and lips were the most common injection sites. Clinical outcomes were satisfactory, and improved contour was achieved in most patients after repeated injections. Cryopreservation of excess tissue for future injection is promising since repetitive injections are often required after resorption of microfat grafts. In our study, the survival of cryopreserved tissue cocktail or fat was comparable to that of fresh fat grafts and is therefore an effective adjuvant method for facial rejuvenation.

Effects of Expanded Human Adipose Tissue-Derived Mesenchymal Stem Cells on the Viability of Cryopreserved Fat Grafts in the Nude Mouse

Adipose-derived mesenchymal stem cells (AdMSCs) augment the ability to contribute to microvascular remodeling in vivo and to modulate vascular stability in fresh fat grafts. Although cryopreserved adipose tissue is frequently used for soft tissue augmentation, the viability of the fat graft is poor. The effects of culture-expanded human adipose tissue-derived mesenchymal stem cells (hAdMSCs) on the survival and quality of the cryopreserved fat graft were determined. hAdMSCs from the same donor were mixed with fat tissues cryopreserved at -70 °C for 8 weeks and injected subcutaneously into 6-week-old BALB/c-nu nude mice. Graft volume and weight were measured, and histology was evaluated 4 and 15 weeks post-transplantation. The hAdMSC-treated group showed significantly enhanced graft volume and weight. The histological evaluation demonstrated significantly better fat cell integrity compared with the vehicle-treated control 4 weeks post-transplantation. No significant difference in graft weight, volume, or histological parameters was found among the groups 15 weeks post-transplantation. The hAdMSCs enhanced the survival and quality of transplanted cryopreserved fat tissues. Cultured and expanded hAdMSCs have reconstructive capacity in cryopreserved fat grafting by increasing the number of stem cells.