title: Therapeutic Effects of Intra-Articular Ultrapurified Low Endotoxin Alginate Administration on Experimental Osteoarthritis in Rabbits.
abstract: OBJECTIVE
  We have developed an ultrapurified low endotoxin alginate (UPLE alginate), which can drastically reduce endotoxin levels. Our purposes were to examine the effects of UPLE alginate administration on osteoarthritis (OA) progression and to determine the adequate molecular weight of the UPLE alginate for therapeutic effects.
  
  
  METHODS
  To induce knee OA, 35 Japanese White rabbits underwent anterior cruciate ligament transection. Intra-articular injections of 0.3 mL solution of each material were started at 4 weeks postoperatively for a total of 5 weekly injections. Seventy knees were divided into the following groups: AL430 (430 kDa molecular weight UPLE alginate), AL1000 (1,000 kDa), AL1700 (1,700 kDa), HA (hyaluronan), and NS (normal saline). At 9 weeks postoperatively, all knees were assessed macroscopically, histologically, and mechanically.
  
  
  RESULTS
  Macroscopically, the UPLE alginate groups exhibited milder cartilage degradation compared to that of the NS and HA groups. Histological findings of the UPLE alginate groups showed an obvious reduction in the severity of OA. The histological scores of Kikuchi et al. were superior in the alginate treatment groups compared to the NS group. The friction coefficient of the AL1000 group was significantly lower than that of the NS and HA groups.
  
  
  CONCLUSIONS
  This study indicates that our UPLE alginates, especially AL1000, have promising potential as an effective agent in preventing OA progression.
authors.affiliation: Department of Orthopaedic Surgery, Hokkaido University School of Medicine, Sapporo, Japan.
authors.forename: Tatsuya
authors.initials: T
authors.lastname: Igarashi
authors.affiliation: Department of Orthopaedic Surgery, Hokkaido University School of Medicine, Sapporo, Japan.
authors.forename: Norimasa
authors.initials: N
authors.lastname: Iwasaki
authors.affiliation: Department of Orthopaedic Surgery, Hokkaido University School of Medicine, Sapporo, Japan.
authors.forename: Daisuke
authors.initials: D
authors.lastname: Kawamura
authors.affiliation: Department of Orthopaedic Surgery, Hokkaido University School of Medicine, Sapporo, Japan.
authors.forename: Yukinori
authors.initials: Y
authors.lastname: Tsukuda
authors.affiliation: Department of Orthopaedic Surgery, Hokkaido University School of Medicine, Sapporo, Japan.
authors.forename: Yasuhiko
authors.initials: Y
authors.lastname: Kasahara
authors.affiliation: Division of Human Mechanical Systems and Design, Faculty of Engineering, Hokkaido University, Sapporo, Japan.
authors.forename: Masahiro
authors.initials: M
authors.lastname: Todoh
authors.affiliation: Division of Human Mechanical Systems and Design, Faculty of Engineering, Hokkaido University, Sapporo, Japan.
authors.forename: Shigeru
authors.initials: S
authors.lastname: Tadano
authors.affiliation: Department of Orthopaedic Surgery, Hokkaido University School of Medicine, Sapporo, Japan.
authors.forename: Akio
authors.initials: A
authors.lastname: Minami
keywords: alginate; cartilage; intra-articular injection; molecular weight; osteoarthritis