Preparation and in vivo biocompatibility of a novel thermosensitive hydrogel
- VernacularTitle:温敏凝胶制备及其在体内的生物相容性评价
- Author:
Yu HE
;
Shuhua YANG
;
Tao LI
- Publication Type:Journal Article
- From:
Chinese Journal of Tissue Engineering Research
2008;12(6):1157-1160
- CountryChina
- Language:Chinese
-
Abstract:
BACKGROUND: Thermosensitive hydrogel materials present stability at human body temperature, which is necessary for its application as a medical implant, thus the lower critical solution temperature (LCST) of thermosensitive hydrogel should be beyond the human body temperature by adjustment.OBJECTIVE: To prepare a thermosensitive hydrogel poly-N-isopropylacrylamide-co-N-hydroxymethylacrylamide P(NIPAAm-co-NHMPA) with over 37 ℃ LCST, and primarily appraise its safety as a medical implant in vivo.DESIGN: Random, non-blind, group control, animal experimental study.SETTING: Department of Orthopaedics, Union Hospital, Tongji Medical College, Huazhong University of Science & Technology(HUST).MATERIALS: The experiments were carried out in the Central Laboratory, Union Hospital, Tongji Medical College, HUST and the Key Laboratory of Biomedical Polymer Materials of the Ministry of Education, College of Chemistry, Wuhan University between January and October in 2007. NIPAAm monomer and NHMPA monomer were purchased from Aldrich Company, crosslinking agent N, N'-methylene bisacrylamide from Fluka Company, and initiator ammonium persulfate and accelerating agent tetramethyl ethylene diamine from Sigma Company.METHODS: ①Taking ammonium persulfate and tetramethyl ethylene diamine as oxidation-reduction initiation system, while N, N'-methylene bisacrylamide as cross-linking agent, P-NIPAAm-co-NHMPA was prepared with the addition of NHMPA in the reaction system. LCST was determined by shrinking tests.②A series of biocompatibility tests such as sensitization test, acute systemic toxicity test, genetic toxicity test and implantation test were conducted in several experimental animals to evaluate the safety of the implant. MAIN OUTCOME MEASURES: The erythema and edema of stimulated lesions were recorded in sensitization test; the general state of each animal in acute systemic toxicity test were recorded 4, 24, 48 and 72 hours after injection; in genetic toxicity test, mouse bone marrow polychromatic erythrocyte (PEC) micronucleus was counted six hours after injection under microscope; sections after implantation were observed under light microscope.RESULTS: ①Synthesized hydrogel showed thermosensitive character and the LCST was 38 ℃.②In sensitization test, there was no erythema and edema occurred after leaching liquor and saline were injected; acute systemic toxicity test result revealed no symptom of toxicity; the genetic toxicity test suggested no difference of PEC frequency between experimental group and negative control group; in vivo implantation test, the inflammation around the material was mild and limited.CONCLUSION:P(NIPAAm-co-NHMPA) shows good biocompatibility and can be potentially used as an implant material.
