Biocompatibility

Question 1

*What is biocompatibility?

Answer 1

The ability of a material to perform with an appropriate host response in a specific application.

i.e. Response changes depending on whereabouts in the body material is placed.

Question 2

Define a long term device

Answer 2

The ability of the device to perform its intended function with the desired degree of incorporation in the host, without eliciting any undesirable local or systemic effects in that host

I.e. no inflammatory/hypersensitivity responses

Question 3

Define short term device

Answer 3

The ability of the device to carry out its intended function within the flowing blood with minimum interaction between device and the blood that adversely affects its performance and without inducing uncontrolled activation of cellular or plasma protein cascades

I.e. without blood clotting or activating the complement system

Complement system: Part of the immune system made of plasma proteins.

Question 4

Define tissue engineering scaffold/matrix

Answer 4

The ability to perform as a substrate that will support the appropriate cellular activity such that there is the facilitation of molecular and mechanical signalling systems, in order to optimise tissue regeneration

Question 5

*Define in vitro testing and it’s advantages and disadvantages.

Answer 5

In vitro testing is the assessment of materials using cell or tissue culture techniques to assess biological interactions with materials

Advantages: rapid inexpensive and reduces animal testing

Disadvantages: Typically fails to reproduce the biological complexity of the in vivo situation, which involves multiple interactions between cells on local and systemic levels

Question 6

*Define in vivo and it’s advantages and disadvantages.

Answer 6

In vivo is the assessment of materials within a living organism or cell, usually animals.

Advantages: More accurate and detailed results.

Disadvantages: Expensive, ethical dilemmas, time consuming, strict testing regulations.

Question 7

*Define blood compatibility and describe strategies for blood material interactions.

Answer 7

Blood compatibility is the property of a material or device that permits it to function in contact with blood without inducing adverse reactions
I.e. don’t induce thrombus, clot or embolism, destroy circulating blood components, or activate the compliment system
A blood material interaction (BMI) assessment is preferred over blood compatibility, which considers blood chemistry, blood contacting surface, blood flow regime, and interaction time

Question 8

*What are the assessment methods for biocompatibility standards?

Answer 8

Standards organisations and regulatory bodies (FDA, BSI, EU, ISO) have developed a matrix document indicating methods appropriate for specific applications.
E.g. ISO 10993 biological evaluation of medical devices