Biomedical subjects

Eben Alsberg

Publications and source records attributed to Eben Alsberg.

3 recordsLinked to original sources

PubMed2003

Tissue-engineered large intestine resembles native colon with appropriate in vitro physiology and architecture.

OBJECTIVE: Novel production and in vitro characterization of tissue engineered colon. SUMMARY BACKGROUND DATA: The colon provides important functions of short chain fatty acid production, sodium and water absorption, and storage. We report the first instance of tissue-engineered colon (TEC) production from autologous cells and its in vitro characterization. METHODS: Organoid units, mesenchymal cell cores surrounded by a polarized epithelia derived from full thickness sigmoid colon dissection from neonatal Lewis rats, adult rats, and tissue engineered colon itself, were implanted on a polymer scaffold into the omentum of syngeneic hosts. TEC was either anastomosed at 4 weeks or excised for Ussing chamber studies or histology, immunohistochemistry, and terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate-digoxigenin nick end labeling assay. RESULTS: TEC was generated by 100% of all animals without regard to tissue source, the first instance of engineered intestine from adult cells or an engineered tissue. TEC architecture is identical to native with muscularis propria staining for actin, acetylcholinesterase detected in a linear distribution in the lamina propria, S100-positive cells, ganglion cells, and a terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate-digoxigenin nick end labeling assay similar to native colon. Ussing chamber data indicated in vitro function consistent with mature colonocytes, and a positive short circuit current response to theophylline indicating intact ion transfer. TEM showed normal microarchitecture. Colon architecture was maintained in anastomosis with gross visualization of fluid uptake. CONCLUSIONS: TEC can be successfully produced with fidelity to native architecture and in vitro function from neonatal syngeneic tissue, adult tissue, and TEC itself.

Animals↗

PubMed2002

Engineering growing tissues.

Regenerating or engineering new tissues and organs may one day allow routine replacement of lost or failing tissues and organs. However, these engineered tissues must not only grow to fill a defect and integrate with the host tissue, but often they must also grow in concert with the changing needs of the body over time. We hypothesized that tissues capable of growing with time could be engineered by supplying growth stimulus signals to cells from the biomaterial used for cell transplantation. In this study, chondrocytes and osteoblasts were cotransplanted on hydrogels modified with an RGD-containing peptide sequence to promote cell multiplication. New bone tissue was formed that grew in mass and cellularity by endochondral ossification in a manner similar to normal long-bone growth. Transplanted cells organized into structures that morphologically and functionally resembled growth plates. These engineered tissues could find utility in treating diseases and injuries of the growth plate, testing the effect of experimental drugs on growth-plate function and development, and investigating the biology of long-bone growth. Furthermore, this concept of promoting the growth of engineered tissues could find great utility in engineering numerous tissue types by way of the transplantation of a small number of precursor cells.

Alginates↗

PubMed2002

Tissue-engineered colon exhibits function in vivo.

BACKGROUND: Postcolectomy morbidities include important changes in enterohepatic circulation, stool microbiology, and absorption. The surgical substitution of an ileal pouch for the absent colon also has a number of serious complications. We report in vivo colon replacement by tissue-engineered colon (TEC) in lieu of an ileal pouch. METHODS: End-ileostomies were created in 22 male Lewis rats. In 11 animals, side-to-side ileum-TEC anastomosis was performed 1 cm from the stoma. This group was compared with end-ileostomy alone. Serial weights were measured, and animals were harvested sequentially for assessment of histologic signs of pouchitis. Transit times, stool dry and wet weights, and serum and stool colon function markers were collected. RESULTS: Animals survived 41 days. Weight loss was more than 1.5 times greater in the end-ileostomy alone group compared with the ileum-TEC group. Transit times were significantly longer in the ileum-TEC group than the end-ileostomy alone group, with lower stool moisture content and higher total serum bile acids. Animals without TEC had statistically significant hyponatremia, elevated serum urea nitrogen, and lower stool short chain fatty acids (13.5 micromol/kg vs 84.2) with an abnormal distribution. CONCLUSIONS: TEC successfully recapitulates some major physiologic functions of native large intestine in vivo.

Anastomosis, Surgical↗