Polyethylene gel in the subcutaneous tissue of rats: histopathologic and systemic evaluation.
OBJECTIVE
To evaluate the histological and systemic response to subcutaneous injection of polyethylene gel in rats.


METHODS
Twenty-one white male rats were divided into 3 groups (G): G1 and G2 received subcutaneous polyethylene gel injection in the dorsal midline and were sacrificed at 30 and 60 postoperative days, respectively. G3 was not exposed to the polyethylene gel and was sacrificed after 60 days. Blood levels of lactate dehydrogenase (LDH), creatine kinase (CK), and alkaline phosphatase (ALP) were evaluated. The heart, kidney, liver, adrenal gland, injection site, and adjacent tissues were histologically examined. The results were submitted to statistical analysis.


RESULTS
There was no clinical evidence of extrusion, reduction of the injected volume, or abnormalities in the adjacent tissues. Blood levels of CK and LDH were normal and similar in all groups. ALP levels were significantly lower in G2 than in G1 and G3. The systemic organs were normal on histological examination in the 3 groups evaluated. Microscopically, the polyethylene gel was surrounded by a thin pseudocapsule formation and minimal inflammatory cell response, which decreased from G1 to G2.


CONCLUSIONS
The subcutaneous injection of polyethylene gel in rats elicited minimal local inflammatory response and no systemic side effects.
Oculoplastic Division, Department of Ophthalmology, Botucatu School of Medicine-UNESP, Botucatu-SP, Brazil. sartioli@fmb.unesp.br
Silvana A
SA
Schellini
Gislaine P M
GP
Zimmermann
Erika
E
Hoyama
Claudia H
CH
Pellizon
Carlos R
CR
Padovani
Dinesh
D
Selva
D000818:Animals; D001672:Biocompatible Materials; D001707:Biopsy, Needle; D004195:Disease Models, Animal; D005782:Gels; D007150:Immunohistochemistry; D007279:Injections, Subcutaneous; D008297:Male; D020959:Polyethylene / Q000008:administration & dosage* / Q000009:adverse effects; D019736:Prostheses and Implants; D011897:Random Allocation; D051381:Rats; D017208:Rats, Wistar; D012016:Reference Values; D012680:Sensitivity and Specificity; D012869:Skin Absorption / Q000187:drug effects / Q000502:physiology; D040521:Subcutaneous Tissue / Q000187:drug effects / Q000473:pathology*
D001672:Biocompatible Materials; D005782:Gels; D020959:Polyethylene