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Background: Fat grafts are increasingly applied in augmenting soft tissue defects and correcting static wrinkles, but the outcome is always unpredictable because of high absorption rate. Perilipin1 (Plin1) and perilipin2 (Plin2), two perilipin family proteins on lipid droplets in adipocytes, are reported to be used as biomarkers to evaluate adipocyte regeneration in vivo. Aims: The aim of this study was to assess the efficacy of glabellar wrinkle correction with autologous fat grafting and to observe human adipose regeneration in a nude mouse model. Patients/Methods: Ten patients with 16 moderate or severe glabellar wrinkles underwent wrinkle correction by subcutaneously injecting autologous lipoaspirates obtained from the abdomen. The injection dose was 0.05 ml per 5 mm. The aspirated adipose tissue (0.05 ml) was also injected under the scalps of nude mice. Fat grafts were explanted at 3, 7, 15, 30, and 120 days after transplantation and the dynamic cellular changes were evaluated by HE staining and immunostaining of Plin1 and Plin2. Results: Among the sixteen wrinkle lines, thirteen were obviously improved 4 months after procedure. Eight of the ten patients were satisfied with their wrinkle correction effects. The fat grafts demonstrated a continuous changing process from degeneration to regeneration in the mouse model without significant absorption and necrosis. It was Plin1, not Plin2 that was expressed in mature adipocytes. After transplantation, Plin1 expression was lost in dead fat cells while Plin2 expression was activated in newly regenerated adipocytes. After 120 days, all the surviving adipocytes were negative for Plin2 but positive for Plin1 again. Conclusions: Micro‐volume fat transplantation was an easy and safe method to improve glabellum wrinkle lines, and the regenerative process of human adipose tissue could be verified in the mouse model. [ABSTRACT FROM AUTHOR]

The existence of multipotent adipose-derived stem cells isolated from human orbital fat (OF) tissue has shown great therapeutic potential in tissue engineering and regenerative medicine. But the use of stem cells for therapeutic applications is influenced by their proliferative and differentiation potentials, which may be affected by the age of the donor. So far there is little knowledge about the effects of donor age on the biological properties of human orbital adipose-derived stem cells (OASCs). The intraorbital fat protrusion in the lower eyelids occurs as an aging process, and the protruded fat is routinely removed during aesthetic surgeries. Based on the ease of OF harvest and the availability of OASCs, we investigated in this study the relationship between age and the differentiation and proliferation potentials of human OASCs. Human orbital adipose samples were harvested from young (with normal lower eyelid appearance) and old donors (having protruded fat pads in the lower eyelids). The morphological properties of orbital adipocytes were assessed and the fat cell size displayed a decreasing trend with advancing age. OASCs were isolated from the fat samples, expanded in vitro and cultured under appropriate inducive conditions. Compared to the young cells, although no difference was found in the cell yield and phenotype expression, aged OASCs showed fewer progenitor cell numbers, reduced proliferative rates, increased senescent features and decreased differentiation potentials towards adipogenic, osteogenic and chondrogenic lineages. Our data suggested that using autologous OASCs from elderly patients for potential therapeutic purposes might be restricted. [ABSTRACT FROM AUTHOR]

In old population, there is often a protrusion of the orbital fat pad underlying the skin in the lower eyelids, giving an aspect of palpable pouches. It is generally thought that orbital fat hyperplasia is the main contributing factor to the formation of baggy lower eyelids, and resection of excessive orbital fat pad is routinely performed during the eyelid cosmetic surgery. In our clinical study, however, it was revealed that the adipocytes in orbital fat tissue from older people became smaller compared to those from the young individuals. Based on this finding, we hypothesize that the orbital fat size may not increase, but decrease with age, and the declined fat depot volume is related to the reduced fat cell size and impaired differentiation of preadipocytes into fat cells. Adipose-derived stem cells (ASCs) are a population of postnatal stem cells residing in the fat tissue, capable of differentiating into preadipocytes and subsequently into mature fat cells throughout the lifespan. As preadipocytes are a substantial component of fat tissue and can greatly influence the fat composition and function, we speculate that orbital adipose-derived stem cells can be used as an excellent model to determine effects of aging on orbital fat. By evaluating the age-related changes in preadipocyte number, replication, and differentiation, we can reveal alterations in orbital fat cellularity and function with age, and investigate the relationship between orbital fat volume and the of baggy lower eyelid formation. [ABSTRACT FROM AUTHOR]

Abstract: Adipose tissue derived stem cells (ASCs) based therapies for the repair and regeneration of various tissues have been widely investigated recently because of their multilineage potential and self-renewal capability. Our previous study demonstrated that autologous ASCs loaded onto natural coral scaffolds could repair cranial critical-sized defects (CSDs) in a canine model. The objective of this study was to determine whether the use of allogeneic ASCs could heal the same defect without the use of immunosuppressive therapy. The pedigree mismatch, mixed lymphocyte reaction assays (MLRs) and allogeneic skin graft experiments were performed to confirm unrelated ASC donors and recipients. A total of 12 adult Beagle dogs were enrolled in this study and divided into two groups. Bilateral cranial CSDs were created in each animal. The right-side defect was treated with allogeneic ASCs delivered onto a coral scaffold, and the left defect was either filled with an autologous ASC/coral composite (Group 1, n = 5) or with one coral scaffold alone (Group 2, n = 5). The systematic immune response and bone healing were evaluated postoperatively. The results showed that allogeneic ASC transplantation did not induce a systemic immune response by the hosts, and allogeneic ASCs could repair the cranial CSDs in an analogous way to that of the autologous cells. Moreover, both the green fluorescently labeled allogeneic and autologous ASCs were detected within the lacunae of newly formed bone in the defect site at 24 weeks, illustrating that the grafted ASCs contributed directly to bone regeneration in vivo. Thus, we concluded that allogeneic ASCs have the capacity to regenerate bone within craniofacial defects, providing an alternative source of seed cells for bone tissue engineering. [Copyright &y& Elsevier]

Abstract: Human adipose-derived stem cells (ASCs) have the ability to differentiate into osteoblasts and thus the potential therapeutic use to tissue-engineer bone, so a reliable method for cell storage is necessary. The aim of this study was to determine whether a simple method of cryopreservation with 10% Me2SO as a protectant had an effect on proliferation potential and osteogenic differentiation of ASCs isolated from fresh human adipose tissue. ASCs were harvested from 6 human lipoaspirates and each was halved for either cryopreservation in liquid nitrogen for 2 weeks or for control culture. Cells from the second-passage were plated at a density of 5000cells/well in 24-well plates and cultured with or without osteogenic media for 14 days. Cell surface antigens were used to identify the cryopreserved ASCs by flow cytometry. The proliferation rate of both populations was evaluated using a cell DNA assay. To detect osteogenic differentiation of both the cryopreserved and non-cryopreserved populations, determination of osteoblastic protein production (alkaline phosphatase and osteocalcin) and excellular matrix calcification (calcium content) was applied. The expression of osteoblastic-associated genes was also analyzed using reverse-transcription polymerase chain reaction. These results demonstrate that cryopreservation has no effect on the phenotype, proliferation or osteogenic differentiation of human ASCs, showing cryopreserved human ASCs might be applied for bone tissue engineering. [Copyright &y& Elsevier]