Detection of familial adenomatous polyposis with orthogonal polarized spectroscopy of the oral mucosa vasculature.

Familial Adenomatous Polyposis (FAP) is an autosomal dominant disease characterized by the development of multiple colonic polyps at younger age with a near 100% lifetime risk of colorectal cancer. The determination of FAP is made after extensive clinical evaluation and genetic testing of at risk individuals. We investigated a novel spectro-polarimetric imaging system capable of capturing high-resolution images of the oral mucosa at different wavelengths in an attempt to distinguish patients with FAP from controls. Results of a clinical trial show that the system is capable of separating FAP positive individuals from controls by measuring the individuals' oral vascular density and complexity.

Factors of osteogenesis influencing various human stem cells on third-generation gelatin/ß-tricalcium phosphate scaffold material.

Human bone marrow-derived stem cells (hBMSCs) and adipose-derived stem cells (hASCs) have been used to regenerate bone. Both sources are claimed to have comparable osteogenic potential, but few comparative studies are available. Third-generation biomaterials have been developed to reduce steps in regenerating tissues. For osteogenesis gelatin/ß-tricalcium phosphate (ß-TCP) scaffolds with incorporated controlled-release bone morphogenetic protein-2 (BMP-2) as third-generation biomaterials were recently developed. So far, few studies on protein-induced osteogenesis versus chemical-induced osteogenesis have been performed. This study evaluates the osteogenic potential of hBMSCs versus hASCs derived on gelatin/ß-TCP scaffolds in vitro under four different conditions. Gelatin/ß-TCP scaffolds with and without incorporated controlled-release BMP-2 were seeded with hBMSCs or hASCs under oscillating fluid conditions in osteogenic (OS) medium or growth medium (GM). All were evaluated radiologically (computed tomography [CT] scan), histologically, biomechanically, and for gene expression at 1, 2, 4, and 6 weeks. The highest radiological densities were seen in specimens at 6 weeks with controlled-release BMP-2, close to native bone. HBMSCs, hASCs, OS, and GM conditions resulted in similar bone formation with gelatin/ß-TCP scaffolds and incorporated controlled-release BMP-2. This was confirmed histologically by Toluidine Blue and van Kossa staining and biomechanically. Gene expression studies of these specimens showed the presence of preosteoblasts, transitory osteoblasts, and secretory osteoblasts. Specimens comprised of gelatin/ß-TCP scaffolds without incorporated controlled release BMP-2 in OS medium showed lesser bone formation. hASCs and hBMSCs have similar osteogenic potential. hASCs are an attractive alternative to hBMSCs for bone regeneration using third-generation gelatin/ß-TCP scaffolds with incorporated controlled-release BMP-2.

Measurement of oxygen saturation in the retina with a spectroscopic sensitive multi aperture camera.

We introduce a new multi aperture system capable of capturing six identical images of the human fundus at six different spectral bands. The system is based on a lenslet array architecture and is well suited for spectroscopy application. The multi-aperture system was interfaced with a fundus camera to acquire spectroscopic sensitive images of the retina vessel and ultimately to calculate oxygen saturation in the retina in vivo. In vitro testing showed that the system is able to accurately reconstruct curves of partially oxygenated hemoglobin. In vivo testing on healthy volunteers was conducted and yielded results of oxygen saturation similar to the one reported in the literature, with arterial SO(2) approximately 0.95 and venous SO(2) approximately 0.5.