Classification of biocompatibility
1. Blood compatibility: The material is used for direct contact between the cardiovascular system and blood, mainly to investigate the interaction with blood.
Blood compatibility requirements: Anti-platelet thrombosis, anti-coagulation, anti-hemolysis, anti-leukopenia, anti-complement system, anti-plasma protein adsorption, anti-cytokine adsorption.
2. Histocompatibility (general biocompatibility): The material is in contact with tissues and organs outside the cardiovascular system, and the interaction with the tissues is mainly investigated.
Histocompatibility requirements: Cell adhesion, non-inhibition of cell growth, cell activation, resistance to cytoplasmic changes, anti-inflammatory, non-antigenic, non-mutagenic, non-carcinogenic, non-teratogenic.
Evaluation Criteria for Biocompatibility
1. The characteristics of biological evaluation standards in ISO
(1) The classification of medical devices is clarified, and the contact parts are divided into three categories: surface contact, external and internal contact, and internal implantation;
(2) In terms of contact time, the contact time of less than 24h is classified as one-time contact, the short-term and medium-term contact time is greater than 24h to 30 days, and the contact time of more than 30 days is long-term contact;
(3) Biological evaluation tests are divided into two categories: basic evaluation tests and supplementary evaluation tests. Subchronic and subacute toxicity tests were included in the basic evaluation test items, and the pyrogen test items were cancelled; Two items of reproductive and developmental toxicity and biodegradation test were added to the supplementary evaluation test.
2. The difference between Chinese biological evaluation standards and international standards
(1) List the pyrogen test as a biological evaluation test for basic evaluation;
(2) List the hemolysis test as a biological evaluation test;
(3) Include subacute (subchronic) toxicity test in the supplementary evaluation part.