Adipose-derived stem cells significantly increases collagen level and fiber maturity in patient-specific biological engineered blood vessels.

Tissue engineering has driven significant research in the strive to create a supply of tissues for patient treatment. Cell integration into engineered tissues maximizes functional capabilities, however, issues of rejection remain. Autologous cell sources able to solve this issue are difficult to identify for tissue engineering purposes. Here, we present the efficacy of patient-sourced cells derived from adipose (adipose-derived stem cells, ASCs) and skin tissue (dermal fibroblasts, PtFibs) to build a combined engineered tunica media and adventitia graft, respectively. Patient cells were integrated into our lab's vascular tissue engineering technique of forming vascular rings that are stacked into a tubular structure to create the vascular graft. For the media layer, ASCs were successfully differentiated into the smooth muscle phenotype using angiotensin II followed by culture in smooth muscle growth factors, evidenced by significantly increased expression of αSMA and myosin light chain kinase. Engineered media vessels composed of differentiated ASCs (ASC-SMCs) exhibited an elastic modulus (45.2 ± 18.9 kPa) between that of vessels of undifferentiated ASCs (71.8 ± 35.3 kPa) and control human aortic smooth muscle cells (HASMCs; 18.7 ± 5.49 kPa) (p<0.5). Tensile strength of vessels composed of ASCs (41.3 ± 15.7 kPa) and ASC-SMCs (37.3 ± 17.0 kPa) were higher compared to vessels of HASMCs (28.4 ± 11.2 kPa). ASC-based tissues exhibited a significant increase in collagen content and fiber maturity- both factors contribute to tissue strength and stability. Furthermore, vessels gained stability and a more-uniform single-tubular shape with longer-term 1-month culture. This work demonstrates efficacy of ASCs and PtFibs to create patient-specific vessels.

Long-Term Weight Loss with Body Contour Surgery After Roux-en-Y Gastric Bypass.

BACKGROUND: Bariatric surgery is accepted as an evidence-based treatment for morbid obesity. Many patients seek out body contour surgery afterwards to correct acquired deformities. This study seeks to better define the impact of body contour surgery on long-term weight loss. METHODS: This study is a single-center retrospective review of 78 patients who underwent body contouring surgery post-Roux-en-Y gastric bypass compared with 221 matched control patients who underwent Roux-en-Y gastric bypass only. Data was collected for patients at least 7 years post-Roux-en-Y gastric bypass. RESULTS: Patients who underwent both bariatric surgery and body contour surgery maintained mean long-term weight loss of 58 kg. The matched control group mean weight loss over the same time interval was 42 kg. The difference was statistically and clinically significant (p = 0.005). Change in body mass index, percent total weight loss, and percent excess body mass index loss were all statistically significant between the 2 groups. CONCLUSION: Patients who underwent body contour surgery better maintained long-term weight reduction in comparison to those who only had gastric bypass. Further understanding of the etiology of this association is important for patients contemplating body contouring surgery.

Porcine Acellular Peritoneal Matrix in Immediate Breast Reconstruction: A Multicenter, Prospective, Single-Arm Trial.

BACKGROUND: Use of biological implants such as acellular dermal matrices in tissue expander breast reconstruction is a common adjunct to submuscular implant placement. There is a paucity of published prospective studies involving acellular matrices. The authors sought to evaluate a porcine-derived acellular peritoneal matrix product for immediate breast reconstruction. METHODS: A prospective, single-arm trial was designed to analyze safety and outcomes of immediate tissue expander-based breast reconstruction with a novel porcine-derived acellular peritoneal matrix surgical mesh implant. Twenty-five patients were enrolled in this industry-sponsored trial. Patient demographics, surgical information, complications, histologic characteristics, and satisfaction (assessed by means of the BREAST-Q questionnaire) were evaluated. RESULTS: Twenty-five patients (44 breasts) underwent mastectomy with immediate breast reconstruction using tissue expanders with acellular peritoneal matrix. Sixteen reconstructed breasts experienced at least one complication (36 percent). Seroma and hematoma occurred in one of 44 (2.3 percent) and two of 44 breasts (4.6 percent), respectively. Wound dehiscence occurred in four of 44 breasts (9.1 percent). Three subjects experienced reconstruction failure resulting in expander and/or acellular peritoneal matrix removal (6.8 percent); all failures were preceded by wound dehiscence. Histologic analysis showed cellular infiltration and product resorption. Results of the BREAST-Q demonstrated a level of postoperative patient satisfaction consistent with results in the available literature. CONCLUSIONS: Prepared porcine-derived acellular peritoneal matrix is a safe adjunct in immediate two-stage tissue expander-based breast reconstruction. Further studies are required to determine efficacy compared to current commercially available acellular matrices. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, IV.

Mechanical Stimulation Increases Knee Meniscus Gene RNA-level Expression in Adipose-derived Stromal Cells.

Efforts have been made to engineer knee meniscus tissue for injury repair, yet most attempts have been unsuccessful. Creating a cell source that resembles the complex, heterogeneous phenotype of the meniscus cell remains difficult. Stem cell differentiation has been investigated, mainly using bone marrow mesenchymal cells and biochemical means for differentiation, resulting in no solution. Mechanical stimulation has been investigated to an extent with no conclusion. Here, we explore the potential for and effectiveness of mechanical stimulation to induce the meniscal phenotype in adipose-derived stromal cells. METHODS: Human adipose-derived stromal cells were chosen for their fibrogenic nature and conduciveness for chondrogenesis. Biochemical and mechanical stimulation were investigated. Biochemical stimulation included fibrogenic and chondrogenic media. For mechanical stimulation, a custom-built device was used to apply constant, cyclical, uniaxial strain for up to 6 hours. Strain and frequency varied. RESULTS: Under biochemical stimulation, both fibrogenic (collagen I, versican) and chondrogenic (collagen II, Sox9, aggrecan) genes were expressed by cells exposed to either fibrogenic or chondrogenic biochemical factors. Mechanical strain was found to preferentially promote fibrogenesis over chondrogenesis, confirming that tensile strain is an effective fibrogenic cue. Three hours at 10% strain and 1 Hz in chondrogenic media resulted in the highest expression of fibrochondrogenic genes. Although mechanical stimulation did not seem to affect protein level expression, biochemical means did affect protein level presence of collagen fibers. CONCLUSION: Mechanical stimulation can be a useful differentiation tool for mechanoresponsive cell types as long as biochemical factors are also integrated.

An analysis of 72% chromated glycerin used for sclerotherapy: sterility, potency, and cost after extended shelf life.

BACKGROUND: Sclerotherapy is the treatment of reticular veins and telangiectasias of the lower extremities. Sclerosants destroy endothelial tissue and expose subendothelial collagen fibers, which lead to subsequent fibrosis of vessels, thus preventing recanalization. There are several available sclerosants including sodium tetradecyl sulfate (STS), polidocanol (POL), and chromated glycerin (CG) with varying efficacy, potency, side effect profile, and cost. OBJECTIVE: To identify the possible bacterial contamination and potency of CG beyond the current recommended shelf life of 3 months and to prove if CG is as cost effective as other available sclerosants. METHODS: Samples of 72% CG underwent bacterial endotoxin, sterility, and potency analysis at Days 0, 24, and 183. In addition, cost comparison was performed with other commercially available sclerosants including STS and POL. RESULTS: No samples of CG showed any bacterial contamination. All aliquots of glycerin remained sterile at Day 14. Potency at Day 24 was 99.2%, which was the same at Day 183. Cost comparison with other sclerosants revealed that CG is lower cost per milliliter than STS and POL. CONCLUSION: Seventy-two percent CG has no contamination and maintains its reported potency up to 6 months while comparable with the cost of other commercially available sclerosants.

Human acellular dermal matrix (AlloDerm®) dimensional changes and stretching in tissue expander/implant breast reconstruction.

BACKGROUND: Human acellular dermal matrix (HADM) is widely used for post-mastectomy tissue expander/implant breast reconstruction. Since HADM has been shown to stretch following placement in other surgical settings, we hypothesised that stretching would occur in breast reconstruction as well. The goal of the study was to quantify the in situ stretch properties of HADM over time in patients undergoing this procedure. METHODS: This was an open-label, prospective case series in adult women who underwent post-mastectomy tissue expander/implant breast reconstruction using HADM. HADM construct size was determined at postoperative day 1 and month 3 via ultrasound tracking of metallic 3-mm vessel clips embedded in the graft. Dimensional changes were further examined in four equally sized segments (medial, lateral and two central) of the matrix. Patient satisfaction was evaluated at month 3 (a modified version of the Breast Q™ patient questionnaire) and compared with satisfaction reported by a non-HADM reconstruction cohort. RESULTS: A total of 31 patients underwent breast reconstruction with HADM. Mean (standard deviation) perimeter increased from 38 (6) cm on postoperative day 1-42 (7) cm at month 3 (+11%; P=0.002). Surface area increased from 73 (22) to 88 (28) cm2 (+21%; range, 4-35%; P=0.002). The greatest expansion occurred in the HADM medial and lateral segments (range, 18-30% across the four segments). Patient satisfaction was comparable with that of non-HADM patients. Complications in the HADM group included late seroma, red breast syndrome and urinary tract infection. Complications in the non-HADM cohort included cellulitis, expander explantation, delayed wound healing and skin necrosis. CONCLUSIONS: During short-term follow-up, HADM exhibited a modest degree of stretching during tissue expander/implant breast reconstruction and was associated with few complications and a high level of patient satisfaction.