Intracutaneous reactivity study

The modified polymer beads [347] passed all of the standard battery of biocompatibility tests required by the International Organization for Standardization guidelines (ISO 10993). The tests included in vitro coagulation tests (plasma recalcification time), hemolysis study (extraction method), cytotoxicity study using the ISO elution method, etc. In in vivo experiments, extracts of the polymer beads did not elicit pyrogenic irritation or sensitization reactions in laboratory animals (acute systematic toxicity study in the mouse, acute intracutaneous reactivity study in the rabbit, rabbit pyrogen study). 

Irritation testing determines whether the test article will cause irritation to the relevant tissue. Various models are available to test an article, the most common being the intracutaneous reactivity study (IC). In this test, extracts are typically used to inject five 0.2 mL boluses per extract into the skin of rabbits. The injections are usually the size of a mosquito bite. The skin sample area is observed every 24 h for 72 h following the injections and is scored for erythema and edema. The test sites are compared with control sites, and in order for the test article to pass, the difference of the average scores cannot exceed 1. The IC test can also be used with the test article directly if it is small enough to pass through a needle. 

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