Study of microencapsulation for pituitary transplantation: capsule preparation and in vitro study.
We have developed microcapsules using sodium alginate (SA) and Poly-L-Lysine (PLL). A factorial design method of screening was chosen to study influences of different experimental parameters on size and stability of the capsules. We found that air flow affects initial size of the capsules significantly, while the molecular weight (MW) of PLL and incubation time have a positive impact on the expansion when capsules are incubated in sodium citrate (SC). When the capsules were continuously shaken in an attempt to mimic in vivo environmental conditions, those capsules made with optimal parameters (0.1% PLL, 42,000 MW, incubated for 6 minutes; 1.5% SA, incubated for 4 minutes; SC bath 4 minutes; 25# needle; air flow 14L/min) were still intact after 30 days and not totally ruptured until 90 days, while those developed with less strict parameters were ruptured within 2 hours in 50%. We also encapsulated human pituitary adenoma cells using PLL of 80,000 MW and cultured them for 9 days. Adenoma cells, both encapsulated or non-encapsulated, secreted the same amount of hormones. Our preliminary study suggests that selecting optimal combinations of experimental parameters is essential in developing durable microcapsules, which may be potentially used for pituitary transplantation in vivo.
Division of Neurosurgery, Lady Davis Institute for Medical Research, Sir Mortimer B. Davis, Jewish General Hospital, McGill University, Montréal, Québec, Canada.
Z P
ZP
Chen
Y D
YD
Bao
W
W
Gorczyca
G
G
Mohr
D000236:Adenoma; D000464:Alginates / Q000008:administration & dosage; D002214:Capsules; D004337:Drug Carriers; D004339:Drug Compounding; D020723:Glucuronic Acid; D006490:Hemostatics / Q000008:administration & dosage; D006603:Hexuronic Acids; D006801:Humans; D008567:Membranes, Artificial; D008970:Molecular Weight; D010902:Pituitary Gland / Q000637:transplantation*; D011107:Polylysine / Q000008:administration & dosage; D014180:Transplantation / Q000379:methods*; D014407:Tumor Cells, Cultured / Q000378:metabolism / Q000637:transplantation
D000464:Alginates; D002214:Capsules; D004337:Drug Carriers; D006490:Hemostatics; D006603:Hexuronic Acids; D008567:Membranes, Artificial; D011107:Polylysine; D020723:Glucuronic Acid