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Biomedical subjects

Christopher Breuer

Publications and source records attributed to Christopher Breuer.

3 recordsLinked to original sources

Development of a parathyroid hormone-controlled release system as a potential surgical treatment for hypoparathyroidism.

BACKGROUND/PURPOSE: The aim of this study was to develop a surgically implantable controlled release delivery system for parathyroid hormone (PTH) that will maintain calcium homeostasis without the adverse side effects of long-term calcium and vitamin D replacement and can be used for the treatment of hypoparathyroidism. METHODS: Biodegradable poly(lactide-co-glycolide) (PLGA) microspheres loaded with PTH were made using a modification of the double emulsion (water/oil/water) solvent evaporation technique. To simulate the release of PTH from microspheres after implantation in an animal, the in vitro release profile for the PTH microspheres was determined by incubating the PTH microspheres in phosphate-buffered saline, serially sampling the effluent, and determining the concentration of PTH in the effluent over time using an enzyme-linked immunosorbent assay. RESULTS: (1) PTH was successfully incorporated into PLGA microspheres. (2) Controlled release of PTH was demonstrated in vitro over a 3-week period. (3) Release of physiological significant concentrations of PTH was achieved using this methodology. CONCLUSIONS: Controlled release of physiological concentrations of PTH can be achieved using PLGA microsphere encapsulation.

Biocompatible Materials↗

Artificial blood vessel: the Holy Grail of peripheral vascular surgery.

Artificial blood vessels composed of viable tissue represent the ideal vascular graft. Compliance, lack of thrombogenicity, and resistance to infections as well as the ability to heal, remodel, contract, and secrete normal blood vessel products are theoretical advantages of such grafts. Three basic elements are generally required for the construction of an artificial vessel: a structural scaffold, made either of collagen or a biodegradable polymer; vascular cells, and a nurturing environment. Mechanical properties of the artificial vessels are enhanced by bioreactors that mimic the in vivo environment of the vascular cells by producing pulsatile flow. Alternative approaches include the production of fibrocollagenous tubes within the recipient's own body (subcutaneous tissue or peritoneal cavity) and the construction of an artificial vessel from acellular native tissues, such as decellularized small intestine submucosa, ureter, and allogeneic or xenogeneic arteries. This review details the most recent developments on vascular tissue engineering, summarizes the results of initial experiments on animals and humans, and outlines the current status and the challenges for the future.

Animals↗

Potential tissue-engineering applications for neonatal surgery.

Tissue engineering attempts to build neotissue from its cellular building blocks. This neotissue can then be used for reconstructive surgical applications such as replacement of a congenitally abnormal heart valve or repair of a craniofacial abnormality. Since its inception in the late 1980s, tissue engineering has sparked the interests of physicians and scientists alike because of its great potential. Significant progress has been made in this burgeoning branch of science. This article reviews some of the ongoing preclinical and clinical tissue engineering research as it applies to neonatology.

Animals↗