Fabrication of shape-designable cartilage from human induced pluripotent stem cell-derived chondroprogenitors using a cell self-aggregation technique.

With the advancement of tissue engineering technologies, implantable materials have been developed for use in facial plastic surgery, including auriculoplasty and rhinoplasty. Tissue-engineered cartilage comprising only cells and cell-produced extracellular matrix is considered valuable as there is no need to consider problems associated with scaffold absorption or immune responses commonly related to conventional artificial materials. However, it is exceedingly difficult to produce large-sized complex shapes of cartilage without the use of scaffolds. In this study, we describe the production of shape-designable cartilage using a novel cell self-aggregation technique (CAT) and chondroprogenitor cells derived from human induced pluripotent stem cells as the source. The method described does not require special equipment such as bio-3D printers, and the produced tissue can be induced into well-matured cartilage with abundant cartilage matrixin vitro. Using CAT, we were able to generate cartilage in the form of rings or tubes with adjustable inner diameter and curvature, over a range of several centimeters, without the use of scaffolds. Thein vitrofabrication of shape-designable cartilage using CAT is a promising development in facial plastic surgery.

Impact of Immediate Breast Reconstruction on Survival of Breast Cancer Patients: A Single-Center Observational Study.

Although immediate breast reconstruction following mastectomy has become increasingly common, its oncological safety has been debated. We enrolled patients with breast cancer who underwent surgery at Okayama University Hospital between 2007 and 2013. The primary outcome was relapse-free survival (RFS). Secondary outcomes were overall survival and the duration from the surgery to the initiation of adjuvant chemotherapy. We divided into immediate breast reconstruction, mastectomy alone, and breast conservative surgery groups. Outcomes were compared using Cox's regression analysis. A total of 614 patients were included (reconstruction: 125, mastectomy: 128, breast conservative surgery: 361). The median follow-up duration was 79.0±31.9 months. The immediate-reconstruction patients were younger, had more lymph node metastases, and more often received postoperative chemotherapy. The RFS was better after the breast conservative surgery compared to after reconstruction (hazard ratio 0.33, 95% confidence interval: 0.144-0.763). The proportion of local recurrence was highest in the reconstruction group. No patients in the reconstruction group underwent postoperative radiation therapy. However, reconstruction did not affect overall survival or the time to the initiation of adjuvant chemotherapy. Surgeons should explain the risks of breast reconstruction to their patients preoperatively. Careful long-term follow-up is required after such procedures.

An observational study of the impact of immediate breast reconstruction on perioperative inflammatory cytokines.

PURPOSE: Perioperative inflammatory cytokines may be related to cancer proliferation, although few studies have investigated this issue in patients undergoing breast reconstruction surgery. METHODS: We conducted a prospective study of patients scheduled for mastectomy only, mastectomy plus deep inferior epigastric perforator flap reconstruction (DIEP), or mastectomy plus tissue expander reconstruction (TE), with or without axial dissection (Ax), for primary breast cancer. Blood samples were collected for analysis of serum IL-6 and VEGF preoperatively, then within 24 h postoperatively (POD 1), and 4-6 days postoperatively (POD 4-6). We investigated the difference in serum cytokine levels over time for each surgical procedure and the difference in serum cytokine levels among the procedures at the three measurement time points. RESULTS: There were 120 patients included in the final analysis. Serum IL-6 was significantly higher than the preoperative level on POD 1 in patients who underwent mastectomy only, DIEP, or TE and Ax (+), with higher values persisting on POD 4-6 except in those who underwent DIEP. IL-6 was significantly higher after DIEP than after mastectomy only on POD 1, but no differences were observed at POD 4-6. VEGF did not differ significantly among the surgical procedures at any time. CONCLUSIONS: The increase in IL-6 was short term and immediate breast reconstruction is considered a safe procedure.

Fabrication of scaffold-free mesenchyme tissue bands by cell self-aggregation technique for potential use in tissue regeneration.

Three-dimensional cell constructs comprising only tissue-specific cells and extracellular matrix secreted by them would be ideal transplants, but their fabrication in a cell aggregation manner without cell scaffolds relies on random cell self-aggregation, making the control of their size and shape difficult. In this study, we propose a method to fabricate band-shaped tissues by inducing the self-aggregation of cell sheets using the developed cell self-aggregation technique (CAT). Acting as cell aggregation stoppers, silicone semicircular pillars were attached to two positions equidistant from both short ends of the rounded rectangular culture groove and coated with a specifically charged biomimetic polymer as a CAT-inducing surface. Mesenchymal stem cells, chondrocytes, and skeletal myoblast cells seeded on the surface of the culture grooves formed band-shaped aggregates between the two aggregation stoppers following spontaneous detachment with aggregation of the cell sheet from the outer edge of the grooves during day one of culture. The aggregated chondrocyte band matured into a cartilage-like plate with an abundant cartilage matrix while retaining its band shape after two weeks of chondrogenic cultivation. Additionally, the aggregates of mesenchymal stem cells and myoblast cell bands could patch the induced collagen membrane derived from rat subcutaneous tissue like a bandage immediately after their formation and successfully mature into fat and muscle tissues, respectively. These results indicate that, depending on the cell type, scaffold-free band-shaped cell aggregates produced by CAT have the potential to achieve tissue regeneration that follows the shape of the defect viain vitromaturation culture orin vivoorganization.