Microencapsulation of parathyroid tissue with photosensitive poly(L-lysine) and short chain alginate-co-MPEG.
Human parathyroid glands were encapsulated using the alginate-PLL system in this study. In order to improve the mechanical strength and the biocompatibility, the microcapsules were fabricated with a three-layer structure that consisted of alginate/photosensitive poly(L-lysine)/short chain alginate-co-MPEG. These modified microcapsules were used for encapsulating human parathyroid tissue. In vitro experiments revealed that microencapsulated parathyroid glands maintained differentiative properties in culture, and the capsular membrane was freely permeable to the human parathyroid hormone. For in vivo experiments, these capsules were transplanted into parathyroidectomized SD-rats. After parathyroidectomy, serum calcium decreased from 2.25 to 1.68 mmol/L and remained in a constantly low concentration until transplantation. Parathyroidectomized SD-rats were normocalcemic after transplant of encapsulated parathyroid tissue. The microcapsules were then explanted at 12 weeks for examination. Histological evaluations of excised transplants revealed that the microcapsules remained intact structurally and were free of cell adhesions. The results demonstrated that human parathyroid tissue microencapsulated by this system retains stability and is functional both in vitro and in vivo. This encapsulating system will have valuable application for endocrine surgery in the future.
Lee
Chen Hsen
CH
Taipei-Veteran General Hospital, Shih Pai, Peitou, Taipei.
Wang
Yng Jiin
YJ
Kuo
Shyh Ming
SM
Chang
Shwu Jen
SJ
D000464:Alginates; D000818:Animals; D004195:Disease Models, Animal; D004339:Drug Compounding / Q000379:methods*; D006801:Humans; D066298:In Vitro Techniques; D008297:Male; D010280:Parathyroid Glands / Q000637:transplantation*; D016105:Parathyroidectomy; D011092:Polyethylene Glycols / Q000494:pharmacology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D012680:Sensitivity and Specificity; D014183:Transplantation, Heterologous
D000464:Alginates; D011092:Polyethylene Glycols; C028210:monomethoxypolyethylene glycol