Addition of decellularized extracellular matrix of porcine nasal cartilage improves cartilage regenerative capacities of PCL-based scaffolds in vitro.

Composite scaffolds can improve regenerative capacities of scaffolds in various tissue-engineering approaches. In order to generate a 3D printable scaffold that is capable of cartilage regeneration, decellularized extracellular matrix (DECM) of porcine nasal cartilage was added to 3D printed polycaprolactone (PCL) scaffolds. Subsequently, scaffolds (PCL, PCL/DECM and DECM) were seeded with human primary nasoseptal chondrocytes and differentiated with cartilage inductive medium for up to 42 days in vitro. Afterwards samples were analyzed with scanning electron microscopy, histology, biochemical assays and gene expression analysis. In short, results showed cell attachment and proliferation on all scaffolds. There was a trend towards ossification on pure PCL scaffolds, whereas we found evidence for cartilage tissue formation on DECM scaffolds as well as on PCL/DECM scaffolds. Moreover, biochemical analysis indicated an enhanced differentiation on novel PCL/DECM scaffolds. In conclusion, the addition of DECM to 3D printable PCL scaffolds may yield a new composite material for regenerative approaches in cartilage for facial reconstructive surgery. Further research will be necessary to evaluate these findings in vivo.

Characterization of a migrative subpopulation of adult human nasoseptal chondrocytes with progenitor cell features and their potential for in vivo cartilage regeneration strategies.

BACKGROUND: Progenitor cells display interesting features for tissue repair and reconstruction. In the last years, such cells have been identified in different cartilage types. In this study, we isolated a migrative subpopulation of adult human nasoseptal chondrocytes with progenitor cell features by outgrowth from human nasal septum cartilage. These putative progenitor cells were comparatively characterized with mesenchymal stem cells (MSC) and human nasal septum chondrocytes with respect to their cellular characteristics as well as surface marker profile using flow cytometric analyses. Differentiation capacity was evaluated on protein and gene expression levels. RESULTS: The migrative subpopulation differentiated into osteogenic and chondrogenic lineages with distinct differences to chondrocytes and MSC. Cells of the migrative subpopulation showed an intermediate surface marker profile positioned between MSC and chondrocytes. Significant differences were found for CD9, CD29, CD44, CD90, CD105 and CD106. The cells possessed a high migratory ability in a Boyden chamber assay and responded to chemotactic stimulation. To evaluate their potential use in tissue engineering applications, a decellularized septal cartilage matrix was either seeded with cells from the migrative subpopulation or chondrocytes. Matrix production was demonstrated immunohistochemically and verified on gene expression level. Along with secretion of matrix metalloproteinases, cells of the migrative subpopulation migrated faster into the collagen matrix than chondrocytes, while synthesis of cartilage specific matrix was comparable. CONCLUSIONS: Cells of the migrative subpopulation, due to their migratory characteristics, are a potential cell source for in vivo regeneration of nasal cartilage. The in vivo mobilization of nasal cartilage progenitor cells is envisioned to be the basis for in situ tissue engineering procedures, aiming at the use of unseeded biomaterials which are able to recruit local progenitor cells for cartilage regeneration.

A community-based program to facilitate dental care for senior citizens.

This article presents findings of a one-year trial which examined a community-based program in Clinton County, Indiana, to help facilitate entry of senior citizens into the oral health care delivery system. A multifaceted approach addressed the senior citizens' limited knowledge of oral health care, personal barriers to obtaining dental services, and the community's concern for the health of older citizens. Program components included oral health education (newspaper articles, presentations, pamphlet distribution), personalized patient motivation ("Bring-a-Friend" campaign), and oral health screenings (public screenings and "Senior Day at the Dentist"). During the study year, 345 patients visited the dentist, compared to 179 in the baseline year. Ninety-three participated in the two "Senior Day" screenings, and 53 percent of the total 134 screening patients returned for follow-up care. Given its experimental nature, the program was a success.

Teaching oral biology laboratories to large numbers of students by video tape.

A two-laboratory video-taped package was developed and presented to 180 dental, dental hygiene, and dental assisting students. The tapes dealt with (1) the growth of plaque in vitro on nichrome wire and on bovine enamel blocks and with (2) the measurement of plaque pH changes in vivo after a sugar solution rinse. The taped presentation was interrupted at frequent intervals to allow the students to perform the procedures. A program describing the use of the phase microscope was also developed and presented. Results showed that all students were able to perform the procedures satisfactorily and complete the laboratory report in approximately 40 percent less time than was required for the conventional laboratory. Students reported that they felt the video tapes had enabled them to master the required material and understand plaque and the food-host-bacterial interaction. Preparation time was at least twice that for the traditional laboratory exercise, and cost-benefit justification will require use of the video tape packages for several years without major revision.