Catherine K. Huang

Autologous fat transfer national consensus survey: trends in techniques for harvest, preparation, and application, and perception of short- and long-term results.

Background: Despite a perceived interest in autologous fat transfer, there is no consensus as to the best technique or the level of success. The purpose of the present study was to determine the national trends in techniques for harvest, preparation, and application of autologous fat, as well as the success perceived by practitioners. Methods: Comprehensive surveys were sent to 650 randomly selected members of the American Society for Aesthetic Plastic Surgery. The survey was aimed at determining whether autologous fat transfer is a commonly performed procedure and, if so, the specific methods involved and the subjective perception of short- and long-term results. Results: The results of the national consensus survey from 508 surgeons (78 percent return rate) showed the following: (1) autologous fat transfer is a relatively common procedure (57 percent perform >10 annually), but few perform it in high volume (only 23 percent perform >30 annually); (2) techniques for harvest, preparation, and injection rarely deviate from methods discussed in the literature (microcannula, 54 percent; centrifugation, 75 percent; injection in nasolabial fold > lips > nasojugal folds); (3) most physicians believe that at least some graft survival is clinically evident (93 percent); and (4) patients are pleased with the short-term results (good to excellent, 84 percent), despite a lower rate of long-term patient satisfaction (fair to good, 80 percent). Conclusion: Currently, plastic surgeons across the country report a uniformity of autologous fat grafting techniques with acceptable patient satisfaction.

Autologous Fat Transfer for Facial Recontouring: Is There Science behind the Art?

Background: Clinical use of autologous fat grafts for facial soft-tissue augmentation has grown in popularity in the plastic surgery community, despite a perceived drawback of unpredictable results. Methods: The authors’ review of the literature and their current techniques of autologous fat transfer focused on (1) the donor site, (2) aspiration methods, (3) local anesthesia, (4) centrifugation and washing, (5) exposure to cold and air, (6) addition of growth factors, (7) reinjection methods, and (8) longevity of fat grafts. Results: Clinical experience and basic science data showed a slight preference for the following: harvesting abdominal fat with “nontraumatic,” blunt cannula technique, preparation by means of centrifugation without washing or addition of growth factors, and immediate injection of small amounts of fat by means of multiple passes. Quantitative evidence of clinical fat survivability and predictability of volume restoration does not exist, yet reports of patient satisfaction with this procedure do. Clinicians report the need for revisionary procedures to optimize results. Conclusions: Although there is an increased trend in replacement of soft-tissue volume with autologous fat transfer, the literature fails to provide definitive evidence of fat survival. A large-scale clinical assessment using three-dimensional volumetric imaging would provide useful outcome data.

Effects of Singulair (Montelukast) Treatment for Capsular Contracture

BACKGROUND Capsular contracture (CC) is one of the most common complications of breast augmentation surgery. Leukotrienes are implicated in the inflammatory cascade and have been postulated to be involved in the formation of CC. Therefore, leukotriene antagonists Accolate and Singulair have been prescribed by plastic surgeons off-label to treat and prevent CC. To date, there are no studies investigating the efficacy of Singulair on CC. OBJECTIVE The authors retrospectively review a series of patients treated with Singulair to determine whether it improves CC after breast implant surgery. METHODS Nineteen patients treated with Singulair by the senior surgeon (NH) after implant placement from March 2006 to November 2009 were included in this study. Follow-up on Singulair efficacy was obtained by a combination of office chart review and standardized telephone questionnaire. Results were characterized as complete improvement, improvement, no change, or worse. RESULTS Seventeen patients presented with CC resulting from a variety of breast operations. Two patients who had a history of recurrent CC were prescribed Singulair prophylactically immediately after surgery. Twenty-one breasts with existing CC were included in the total. Two (11%) patients became worse, three (16%) patients had no change, five (26%) improved, seven (37%) completely improved, and two (11%) were prevented from having CC formation. CONCLUSION Our preliminary study shows that Singulair improves CC. Breasts with mild CC (Baker score < III) appeared to have better improvement with Singulair compared to those with more severe contracture (Baker score III and IV). Singulair is well tolerated with minimal side effects and can be administered to patients after breast implant surgery to improve CC.

Genetic markers of osteogenesis and angiogenesis are altered in processed lipoaspirate cells when cultured on three-dimensional scaffolds.

Background: Liposuction-derived stem cells (processed lipoaspirate) have recently been shown to be capable of differentiating into bone. Most studies on osteoblastic growth and differentiation have been conducted in a conventional two-dimensional culture system; however, in native bone, osteoblasts are situated in a three-dimensional configuration. There have been limited studies of processed lipoaspirate behavior in three-dimensional systems. The authors studied the influence a three-dimensional scaffold has on the expression of genes related to osteogenesis and angiogenesis in processed lipoaspirate cells. Methods: One million processed lipoaspirate cells were seeded onto two-dimensional poly(l-lactide-co-glycolide) films or in three-dimensional poly(l-lactide-co-glycolide) scaffolds and incubated in osteogenic medium up to 21 days. RNA was extracted and analyzed with quantitative real-time polymerase chain reaction. Results: When an inert three-dimensional poly(l-lactide-co-glycolide) scaffold was introduced, the pattern and sequence of gene expression changed significantly. Processed lipoaspirate cells cultured onto three-dimensional scaffolds had increased expression of interleukin-8 and vascular endothelial growth factor compared with two-dimensional controls at early time points. Osteogenesis markers—alkaline phosphatase, collagen type I, osteocalcin, osteonectin, and osteopontin—were significantly up-regulated in three-dimensional cultures relative to two-dimensional controls after 24 hours and persisted throughout the 21 days. Conclusions: In human processed lipoaspirate cells, the introduction of a three-dimensional scaffold significantly enhances gene markers of angiogenesis and osteogenesis. On three-dimensional scaffolds, processed lipoaspirate cells first up-regulate genes involved with vascular ingrowth and then those involved in bone formation. We believe these differences will significantly impact the design of a bone graft substitute for clinical application.

Pretreatment of poly(l-lactide-co-glycolide) scaffolds with sodium hydroxide enhances osteoblastic differentiation and slows proliferation of mouse preosteoblast cells.

Background: Surface topography is important in the creation of a scaffold for tissue engineering. Chemical etching of poly(l-lactide-co-glycolide) with sodium hydroxide has been shown to enhance adhesion and function of numerous cell types. The authors investigated the effects of sodium hydroxide pretreatment of three-dimensional poly(l-lactide-co-glycolide) scaffolds on the adhesion, differentiation, and proliferation of MC3T3-E1 murine preosteoblasts. Methods: MC3T3-E1 cells were seeded onto three-dimensional poly(l-lactide-co-glycolide) scaffolds with and without 1 M sodium hydroxide pretreatment. Cells were then cultured in osteogenic medium and harvested at varying time points for RNA extraction. Quantitative real-time reverse-transcriptase polymerase chain reaction was performed to measure mRNA expression of several osteogenic marker genes. In addition, cell numbers were determined at varying time points during the culture period. All experiments were performed in triplicate. Results: Pretreatment of three-dimensional poly(l-lactide-co-glycolide) scaffolds with sodium hydroxide resulted in statistically significant up-regulation of mRNA expression of alkaline phosphatase, bone sialoprotein, osteocalcin, and vascular endothelial growth factor during the first 10 days of culture. Histologic analysis demonstrated a striking increase in mineralized cell matrix deposition in the sodium hydroxide–treated group. Cell number was statistically higher in the sodium hydroxide–treated group immediately after cell seeding, suggesting improved adhesion. During the first 24 hours of culture, cells grew faster in the control group than in the sodium hydroxide–treated group. Conclusions: Chemical etching of poly(l-lactide-co-glycolide) scaffolds with sodium hydroxide strongly influences the behavior of MC3T3-E1 preosteoblasts in vitro by enhancing adhesion and differentiation and slowing proliferation. Sodium hydroxide treatment may represent a simple and inexpensive way of improving scaffolds for use in bone tissue engineering.

168 DIFFERENTIATION OF MC3T3-E1 PREOSTEOBLASTIC CELLS ON TWO-DIMENSIONAL POLY(LACTIDE-CO-GLYCOLIDE) (PLGA) FILMS AND THREE-DIMENSIONAL PLGA SCAFFOLDS: A REAL-TIME REVERSE TRANSCRIPTASE-POLYMERASE CHAIN REACTION STUDY.

Purpose This study aimed to investigate the expression of a number of osteogenic and angiogenic markers in MC3T3-E1 cells cultured on two-dimensional (2-D) (PLGA films and three-dimensional (3-D) PLGA scaffolds. Methods MC3T3-E1 cells were incubated in mineralized medium in the absence or presence of 100 ng/mL recombinant human BMP-2 for 2 weeks. Cells were cultured either on 2-D PLGA films or in 3-D PLGA scaffolds and harvested on days 0, 1, 2, 3, 5, 7, 10, and 14. Total RNA was extracted and subjected to quantitative real-time reverse transcriptase-polymerase chain reaction analysis for expression of genes involved in osteogenesis and angiogenesis. Results Expression of BSP and OCN increased when cells cultured on 2-D PLGA films were subjected to differentiation medium containing ascorbic acid and beta-glycerol phosphate for a period of 2 weeks. Treatment with recombinant human BMP-2 resulted in further increases in expression of both genes after day 5. Cells cultured on 3-D PLGA scaffolds showed significantly slowed differentiation as measured by expression of the above two genes. Both genes remained highly responsive to BMP-2 treatment after day 5. OPN expression was elevated when cells were transplanted into 3-D scaffolds. Its expression in cells cultured in 3-D scaffolds was less responsive to BMP-2 treatment than on 2-D films. Expression of VEGF was increased as differentiation proceeded on 2-D films and was enhanced with BMP-2 treatment. Its expression was significantly induced when cells were cultured in 3-D scaffolds. A 2-week culture of cells in 3-D scaffolds resulted in decreased VEGF expression. BMP-2 inhibited VEGF expression in 3-D scaffolds at days 10 and 14. Conclusions The results indicate that MC3T3-E1 cells commit to osteogenic differentiation at a slower rate in 3-D scaffolds than in 2-D scaffolds.

THE EFFECT OF NAOH ON PROLIFERATION AND DIFFERENTIATION OF MC3T3-E1 PREOSTEOBLASTIC CELLS GROWN ON THREE-DIMENSIONAL POLY(L-LACTIDE-CO-GLYCOLIDE) SCAFFOLDS.: 475

Background In creating a biosynthetic scaffold that promotes osteogenesis surface topography is an important variable. It has been demonstrated that chemical etching of poly(l-lactide-co-glycolide) (PLGA) with NaOH enhances adhesion and function of numerous cells types in two-dimensional systems (hepatocytes, endothelial cells, vascular and bladder smooth muscle cells) and three-dimensional (3-D) systems (chondrocytes). This study compares the biological behavior of osteoblasts grown on NaOH-treated PLGA scaffolds and conventional PLGA scaffolds by measuring osteoblast adhesion, differentiation, and proliferation of MC3T3-E1 cells cultured on NaOH-treated 3D PLGA scaffolds and untreated scaffolds. Methods MC3T3-E1 mouse preosteoblast cells were seeded onto 3-D PLGA scaffolds ± 1 M NaOH for 10 minutes. Quantitative real-time RT PCR was performed to measure mRNA expression of osteogenic marker genes. In addition, cell numbers were determined at varying time points. Results Pretreatment of 3D PLGA scaffolds with NaOH resulted in statistically significant up-regulation of mRNA expression of alkaline phosphatase (ALP), bone sialoprotein (BSP), osteocalcin (OCN), and vascular endothelial growth factor (VEGF). A striking increase in mineralized cell matrix deposition in the NaOH group was also observed. Cell number was statistically higher in the NaOH group immediately after cell seeding, suggesting improved adhesion. During the first 24 hours of culture, cell proliferative rates were higher in the control group than the NaOH group. Conclusion Chemical etching of PLGA scaffolds with NaOH enhances adhesion and differentiation and slows proliferation of preosteoblast cells. NaOH treatment may represent an inexpensive way to improve scaffolds for use in bone tissue engineering.