Development of quantitative methods for quality assessment of islets of Langerhans

Transplantation of isolated islets of Langerhans has promising potential to cure type 1 diabetes by inducing long-term normoglycemia and insulin independence. The feasibility of clinical islet transplantations has been established according to the Edmonton Protocol. However, results are variable, and it is not yet possible to predict transplantation outcome from in vitro measurements with islet preparations. Currently, islet enumeration is based on microscopic visualization after staining with a zinc-specific binding dye (dithizone, DTZ) and manual counting with normalization on the basis of an islet equivalent (IE), an islet with volume equivalent to that of a sphere with a 150 Pm diameter. Islet viability is based on a live/dead staining test with two fluorescent dyes, fluorescein diacetate (FDA) and propidium iodide (PI). These methods are operator- dependent and prone to error due to the variability in islet size and shape and are not predictive of transplantation outcome. We developed quantitative assays that allowed reproducible evaluation of meaningful properties that affect the clinical outcome in impure human islet preparations. For purity estimation, we examined light microscopic (LM) morphological analysis of 1-jm sections to estimate the islet volume fraction and compared the results with those of electron microscopy (EM) ultrastructural analysis on the same preparations.

Department dc:contributor.department

Massachusetts Institute of Technology. Dept. of Chemical Engineering.

Grantor dc:publisher

Massachusetts Institute of Technology

Year dc:date.issued

2007

Author dc:creator

• Pisania, Anna

Advisor dc:contributor.advisor

• Clark K. Colton.

• Chemical Engineering.

Statement dc:rights

• M.I.T. theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission. See provided URL for inquiries about permission.

Licence dc:rights.uri

• http://dspace.mit.edu/handle/1721.1/7582

Language dc:language.iso

eng

Handle dc:identifier.uri

http://hdl.handle.net/1721.1/38964

OAI identifier oai:identifier

oai:dspace.mit.edu:1721.1/38964