A New in vitro Invasion Model for Oral Cancer Using an Acellular Allogenic Dermal Matrix (Alloderm) : The Relationship among in vitro Invasion Activity, in vivo Invasion and Metastasis

The purpose of this study was to develop a new in vitro model of cancer invasion using a human dermal equivalent, AlloDerm®. A squamous cell carcinoma line (HSC-2, HSC-3 and OSC20) and a malignant melanoma line (G361) were cultured on AlloDerm® and evaluated histologically to examine destruction of the basement membrane and invasion into the dermis of AlloDerm®. HSC-3 and G361 cells invaded through the basement membrane of AlloDerm® at 21-28 days after seeding, while HSC-2 and OSC20 cells did not. Next, these cells were transplanted into the tongues of nude mice, and the degree of local invasiveness was examined histologically. HSC-3 and G361 cells invaded diffusely to the surrounding tongue tissue, although HSC-2 and OSC20 showed only expansive growth. Further, these cells were transplanted subcutaneously in nude mice to study metastatic activity. Regional and distant metastases were rarely observed after transplantation of HSC-2 and OSC20 cells. On the other hand, HSC-3 and G361 cells frequently metastasized. These findings show a close relationship among in vitro invasiveness on AlloDerm®, in vivo invasiveness, and metastatic activity. This experimental model using AlloDerm® is a potentially new in vitro model of cancer invasion

A New in Vitro Model of Cancer Invasion Using AlloDermR, a Human Cadaveric Dermal Equivalent: a Preliminary Report

Objectives. The first stage in the metastasis of squamous cell carcinoma (SCC) of the oral cavity involves the destruction of the basement membrane and invasion into the submucosal tissue. The purpose of this study is to develop a new in vitro model of cancer invasion using a human dermal equivalent, AlloDermR. Study design. Normal epithelial cells from a gingiva and a SCC line originating from human tongue cancer (HSC-3 and 4 cells) were cultured on AlloDermR, and composites of these cells and AlloDermR were evaluated histologically by HE staining and immunostaining with anti-laminin and type IV collagen antibodies. Furthermore, HSC-3 and 4 cells were transplanted into the tongues of nude mice, and regional lymph node metastases were examined histologically. Results. HSC-3 cells had invaded through the basement membrane into the AlloDermR dermis at 25 days after seeding. Decreases in the levels of laminin and type IV collagen were observed in the locations where HSC-3 had invaded. Metastasis to regional lymph nodes was observed at 3 weeks after transplantation in 4 of 10 (40%) mice. On the other hand, normal epithelial cells and HSC-4 cells did not show invasion into AlloDermR. Lymph node metastasis was not observed in the mice bearing HSC-4 cells. Conclusion. This experimental model using AlloDermR is a potential new in vitro model of cancer invasion

Electrical detection of TV2a-type silicon vacancy spin defect in 4H-SiC MOSFETs

Color centers in silicon carbide (4H-SiC) are potentially usable as spin defects for quantum sensing and quantum information technology. In particular, neutral divacancies (the P6/P7centers, VSiVC 0) and a certain type of silicon vacancies (the TV2a center, VSi - at the k site) are promising for addressing and manipulating single spins. Although the TV2a spin is readable at room temperature, the readout techniques have been limited to luminescence-based ones (e.g., optically detected magnetic resonance). In this study, we demonstrated electrical detection of TV2a-type silicon vacancies at room temperature by using electrically detected magnetic resonance on 4H-SiC metal–oxide–semiconductor field effect transistors (MOSFETs). TV2a spin defects were embedded in the channel region of well-defined 4H-SiC MOSFETs via controlled proton irradiation. The number of detected TV2a spins was estimated to be 10^5. We also found that the charge state of the TV2aspin defect can be controlled by varying the gate voltage applied to the MOSFET

Creation of nitrogen-vacancy centers in SiC by ion irradiation

Color centers which act as stable single photon emitters (SPEs) in wide bandgap semiconductors are key elements for quantum technologies. Silicon carbide (SiC) is regarded as a promising host material for qubit/quantum sensor. It was reported that negatively charged nitrogen-vacancy (NcVsi-) center in SiC (S=1) act as SPS with its zero phonon line (ZPL) around 1170 ~1250 nm. However, detailed characteristics of NcVsi- center in SiC have not yet been clarified since the creation methods for NcVsi- have not yet been established.In this study, various energetic charged particles such as protons, nitrogen (N), silicon (Si) and iodine (I) ions were irradiated into n-type and high purity semi-insulation (HPSI) hexagonal (4H) SiC and subsequently annealed up to 1100C. The creation of NcVsi in SiC are evaluated on the basis of photoluminescence (PL) characteristics.30th International Conference on Defects in Smiconductors (ICDS-30