title: Feasibility of injectable thermoreversible gels for use in intramuscular injection of parathyroid autotransplantation.
abstract: Surgical transplantation of parathyroid tissue into the forearm muscle is one of the most commonly used surgical techniques. While simple, the procedure suffers from drawbacks. This study evaluated the feasibility of thermoreversible gel as an injectable carrier for parathyroid autotransplantation. Polyethyleneglycol-polyalanine-co-phenylalanine (PEG-PAF) thermoreversible gel (sol form at 4 °C, gel form at 37 °C) were manufactured. Thirty-eight Sprague-Dawley rats were divided into two groups (19 control, C group; 19 experimental, P group). The parathyroid glands of rats were excised. Parathyroid tissues were transplanted into the muscle pocket in sternocleidomastoid muscle in the C group. In the P group, the tissues were injected into the same muscle mixed with 0.3 ml thermoreversible gel. The serum levels of parathyroid hormone (PTH), ionized calcium, and phosphorous were measured before surgical procedure, on 7, 21, 56, and 70 days after surgery. Histology and immunohistochemistry were performed. Preoperative median PTH level of the C and the P group were 60.80 and 43.85 pg/ml, respectively (p = 0.641). Seventy days after surgery, median PTH level was 32.8 and 25.61 pg/ml, respectively. On day 70, the PTH level was restored by 54 % in the C group and 56 % in the P group compared to the preoperative value (p = 0.620). There were no significant intergroup differences in the ionized calcium/phosphorous level. Histology and immunohistochemistry revealed the successful transplantation of parathyroid tissues into the muscles in both groups. In conclusion, the PEG-PAF-based thermoreversible gel is a good candidate carrier material for intramuscular parathyroid autotransplantation.
authors.affiliation: Department of Otorhinolaryngology-Head and Neck Surgery, Chuncheon Sacred Heart Hospital, College of Medicine, Hallym University, Chuncheon, Korea.
authors.forename: Hae Sang
authors.initials: HS
authors.lastname: Park
authors.affiliation: Department of Otorhinolaryngology-Head and Neck Surgery, School of Medicine, Ewha Womans University, Seoul, Korea.
authors.forename: Soo Yeon
authors.initials: SY
authors.lastname: Jung
authors.affiliation: Department of Molecular Medicine, School of Medicine, Ewha Womans University, Seoul, Korea.
authors.forename: Ha Yeong
authors.initials: HY
authors.lastname: Kim
authors.affiliation: Department of Chemistry and Nano Science, Ewha Womans University, Seoul, Korea.
authors.forename: Du Young
authors.initials: DY
authors.lastname: Ko
authors.affiliation: Department of Otorhinolaryngology-Head and Neck Surgery, School of Medicine, Ewha Womans University, Seoul, Korea.
authors.forename: Sung Min
authors.initials: SM
authors.lastname: Chung
authors.affiliation: Department of Chemistry and Nano Science, Ewha Womans University, Seoul, Korea.
authors.forename: Byeongmoon
authors.initials: B
authors.lastname: Jeong
authors.affiliation: Department of Otorhinolaryngology-Head and Neck Surgery, School of Medicine, Ewha Womans University, Seoul, Korea. sevent@ewha.ac.kr.
authors.forename: Han Su
authors.initials: HS
authors.lastname: Kim
mesh_terms: D000818:Animals; D005240:Feasibility Studies; D005260:Female; D005782:Gels; D006801:Humans; D007273:Injections, Intramuscular; D008297:Male; D008875:Middle Aged; D010280:Parathyroid Glands / Q000637:transplantation*; D010281:Parathyroid Hormone / Q000097:blood; D010649:Phenylalanine / Q000737:chemistry; D011092:Polyethylene Glycols / Q000737:chemistry; D051381:Rats; D017207:Rats, Sprague-Dawley; D054457:Tissue Scaffolds; D014182:Transplantation, Autologous
chemical_list: D005782:Gels; D010281:Parathyroid Hormone; D011092:Polyethylene Glycols; D010649:Phenylalanine
keywords: Injections; Intramuscular; Parathyroid; Transplantation