title: Effects of micro-encapsulation on morphology and endocrine function of cryopreserved neonatal porcine islet-like cell clusters.
abstract: BACKGROUND
  For the success of clinical islets transplantation, the development of a long-term storage method is necessary. However, the structure of digested islets is scanty for culture and cryopreservation. In this study, the effect of micro-encapsulation to cryopreserved porcine islet-like cell clusters (ICCs) was investigated.
  
  
  METHODS
  The ICCs prepared from neonatal pigs by collagenase digestion and culture technique were cryopreserved and micro-encapsulated in 5% agarose membranes. After cryopreservation, ICC cultured without encapsulation (group A) and cultured with encapsulation (group B) were assessed by comparison with no cryopreserved ICC (control) both in vitro by static incubation test and in vivo in a xenotransplantation study.
  
  
  RESULTS
  Micro-encapsulation was able to maintain the fine morphology and the number of ICCs of group B after 7 days of culture. There were not significant differences in insulin secretion of group B and control on day 1 and 7 of culture (1 day:11+/-0.99, 7 days: 5.30+/-1.08 microU/ICC/hr NS versus control). On day 7 of culture, the retrieval rate of group B (105.2+/-9.8%) is obviously higher compared with group A (63.0+/-6.3%). In the xenotransplatation model, the ICCs of group B showed long survival time (7.9+/-0.4 weeks) and good transplantation effect.
  
  
  CONCLUSIONS
  Our study suggests that micro-encapsulation is one of the useful method for cryopreserved ICC to maintain the fine morphology and effectively recover the endocrine function.
authors.affiliation: First Department of Surgery, Fukui Medical University, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Murakami
authors.forename: H
authors.initials: H
authors.lastname: Satou
authors.forename: T
authors.initials: T
authors.lastname: Kimura
authors.forename: T
authors.initials: T
authors.lastname: Kobayashi
authors.forename: A
authors.initials: A
authors.lastname: Yamaguchi
authors.forename: G
authors.initials: G
authors.lastname: Nakagawara
authors.forename: H
authors.initials: H
authors.lastname: Iwata
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D002470:Cell Survival; D002478:Cells, Cultured; D015925:Cryopreservation; D004339:Drug Compounding; D005260:Female; D007328:Insulin / Q000378:metabolism; D000078790:Insulin Secretion; D007515:Islets of Langerhans / Q000166:cytology* / Q000502:physiology*; D016381:Islets of Langerhans Transplantation / Q000473:pathology; D008297:Male; D015996:Survival Rate; D013552:Swine
chemical_list: D007328:Insulin