Study On The Effect Of Medical Polyacrylamide Hydrogel On Dendritic Cell In Rat

Objective: To explore the possible effect of medical polyacrylamide hydrogel (MPAHG) on immunological system, dendritic cells accumulated within jugular lymph node and the local inflammatory responses were investigated at different time after MPAHG was implanted subcutaneously in SD rats .Besides, the effect of MPAHG on DC (dendritic cell) cultured was also examined.Methods: MPAHG was implanted subcutaneously in SD rats, and liquid silicon, silicone rubber and ePTFE(expanded polytetratluoroethylene) were used for control. At different time after implantation, the gross appearance and histologic changes were observed and the express of S-100 in jugular lymph node was immunohistochemically detected respectively.The OX62,CD80 and CD86 were determined after rat DC was cultured together with the above biomaterials.Results: (i) DC accumulated most in jugular lymph node within 2 week after MPAHG was implanted,and DC accumulation was almost normal at 1 month post-implantation. (ii)In vitro,the four kinds of biomaterials have no significant effect on the express of OX62,CD80 and CD86. (iii) Inflammatory cell infiltration showed up in four collected materials within 2 weeks after the implantation. Later on, inflammatory cells reduce gradually in MPAHG, ePTFE and silincone rubber groups, while maintain a relatively high level in liquid silicone group for a long time, (iv) The implants were being enveloped with some thin fibrous capsules containing fibroblasts, collagens, blood vessels and some inflammatory cells after implantation. Some loose connective tissue builds up the complete dense fibrous capsule consisting of bundles of collagen fibers in MPAHG group 1 week after injection. The thickness of the capsules becomes stable after 1 month. In ePTFE group, the changes are similar to the MPAHG described above. The capsule in silicon liquid group was the most thick.Conclusions: (i)Local inflammatory responses is slight and temporary after MPAHGimplantation, which continues about 2 weeks. DC maybe involves in this process. (ii)A thin fibrous capsule forms early after the injection of MPAHG and remains stable for a long time, (iii) MPAHG has no significant effect on DC cultured,which indicates MPAHG is not an antigen. (iv)The biocompatibility of MPAHG is similar to that of ePTEE, and MPAHG is a kind of ideal biomaterial in reconstruction of soft tissue.