Cellular response | Cell toxicity | GB/ T16886.5—2017 | The device/extract was cultured with cells, its potential cytotoxicity was evaluated by morphology and metabolic activity, such as MTT method | Cell viability > 70% was considered non-cytotoxic. For Zn-based materials, it is generally necessary to dilute the extract over a range of concentrations. Evaluate the result in vitro and in vivo comprehensively |
Tissue response | Intradermal reaction | GB/T16886.10—2017 | Intradermal injection of devices/materials extracts on the back skin of rabbits, to evaluate the non-specific percutaneous acute irritant effects of leachables | Erythema, edema, eschar, etc., were observed and scored according to the standard. The difference between the average scores of the test sample and the control should not be greater than 1.0 |
Implantation & degradation | GB/ T16886.6—2015 | Final devices/materials are implanted by surgical or interventional operation, and the target tissues are collected and observed at different time points to evaluate the local toxic effect of the sample on the living tissue and the degradation process (product) | Different degrees of tissue reactions (aseptic inflammation, fibrous cysts around the implant, etc.) will appear after implantion. With the influence of degradation, the reaction is higher and longer relatively. It's best to set a similar marketed product control |
Immune response | Delayed type hypersensitivity | GB/T16886.10—2017 | The immunity is usually induced by injecting the extract of the device/material plus protein to guinea pigs, and stimulated again after 2 weeks. Then the skin reaction is observed to evaluate the potential contact sensitization of the sample | No local skin erythema, edema and other inflammatory manifestations was considered to be no delayed type hypersensitivity reaction. Allergic reactions do not limit its use necessarily |
Systemic response | Acute systemic toxicity | GB/T16886.11—2011 | Mouse is used routinely. Intravenous and intraperitoneal injection of the device/material extract is contacted with animals. The systemic response is observed to evaluate whether the sample releases toxic substances and produces acute systemic toxicity. The maximum exposure dose is 50 mL·kg-1 body weight | Clinical performance (coat, skin, mucous membranes, respiration, muscles, behavior, etc.) should be observed and no indications. Gross pathological evaluation should be considered if clinically indicated |
(Sub)chronic systemic toxicity | Rat is used routinely. The devices/materials or extracts are (repeatedly) contacted with animals by appropriate routes such as implantation, intravenous or intraperitoneal injection. The dose range is determined according to human safety limits. Clinical manifestations, body weight changes, hematological and clinical biochemical indicators, clinical pathological, gross pathological and histopathological analysis, etc., to evaluate whether the long-term exposure of sample to the human body will release toxic substances and produce (sub)chronic systemic toxicity | Compared with the control group, no significant difference should be observed in each index |
Blood system | Hemolysis | GB/ T16886.4—2003 | Direct contact of blood with the device/material or its extract, measuring the amount of hemoglobin released by erythrocytes to evaluate the degree of erythrocytelysis and hemoglobin release caused by the device/material | Hemolysis rate should be < 5% |
Genetic system | Genotoxicity | GB/ T16886.3—2019 | Mammalian or non-mammalian cells, bacteria, yeast or fungi are used to determine whether a device/material or extract causes genetic mutations, changes in chromosome structure and number, or other changes in DNA or genes. Bacterial gene mutation, chromosomal aberration and mouse lymphoma test are the most used in vitro tests | There should be no significant difference compared to the negative control. If the in vitro test cannot be carried out or the results are confusing, further in vivo chromosome analysis and micronucleus test of mammalian bone marrow cells should be used |