1.Fundamentals Flashcards
Biocompatibility
“The ability of a biomaterial to perform its desired function with respect to a medical therapy, without eliciting any undesirable local or systemic effects in the recipient or beneficiary of that therapy, but generating the most appropriate beneficial cellular or tissue response to that specific situation, and optimizing the clinically relevant
performance of that therapy.”
Host response
prevent bacterial colonization, stimulate the healing, resistance to blood clotting, etc.;
Long-term implantable device
“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”.
Scaffolds or matrices for tissue regeneration
“Ability to perform as a substrate that will support the appropriate cellular activity, including the facilitation of molecular and mechanical signaling systems, in order to optimize tissue regeneration, without eliciting any undesirable effects in those cells, or inducing any undesirable local or
systemic responses in the eventual host”.
Tissue Engineering
“The use of cells, biomaterials and suitable molecular or physical factors, alone or
in combination, to repair or replace tissue to improve clinical outcomes”
Scaffold
“A biomaterial structure that serves as a substrate and guide for tissue repair and
regeneration”
1st generation of biomaterial
Materials available in nature such as wood, gold and ivory;
Replacement of a lost tissue function.
2nd Generation of biomaterials
Developed from materials used in several industrial applications;
Example: stainless steel.
Major issues of 2nd Generation of Biomaterials
Weight;
Interaction with biologic tissues
3rd Generation of biomaterials
Functional biomaterials;
Bioactive materials - able to develop strong interactions with the surrounding
environment.
4th Generation of biomaterials
Multifunctional and biomimetic biomaterials;
Recapitulate complex biological constructs formed by nature.
The Biomaterials’ path
1.Reserch on biomaterials
2.Engineering to develop a medical device
3.Preclinical and clinical testing
4.Regulatory approval
5.Commercialization and clinical application
Challenges on the Biomaterial’s path
-define requirements of the biomaterial
-select appropriate biomaterial
-understand how long does it take to develop a biomaterial for clinical use
Steps
1.indentify a need
2.device design
3.material synthesis
4.material testing
5.fabrication
6.sterilization and packaging
7.device testing
8.regulatory
9.clinical use
10.explant analysis
What kind of questions/issues do you realize when thinking about the sterilization of medical implants?
- How would one sterilize a total hip replacement made of a titanium stem, a cobaltchromium
alloy head, and an ultra-high molecular weight polyethylene acetabular shell? - The same method could be employed for all materials?
- How do you ensure that there is no degradation to the material or its structural properties?
- What are the sterilization methods available for medical implants?
- Which method is best suited for a specific biomaterial?
- How sterilization methods affect material properties such as structural and degradation?
Mechanism of Autoclaving
High-pressure steam (121ºC) disables DNA
Benefits of Autoclaving
efficient
easily accessible
Autoclaving Drawbacks
High Temperature
Which materials can be sterilized with autoclaving?
only metals and ceramics
not polymers
Benefits of sterilization with gamma irradiation
efficient
penetrating
Drawbacks of sterilization with gamma irradiation
radiation damage
Benefits of sterilization with electron-beam irradiation
efficient
surface treatment
Which materials can be sterilized with gamma radiation?
metals
ceramics
polymers
Drawbacks of sterilization with electron-beam irradiation
Radiation damage
limited penetration
Which materials can be sterilized with electron beam radiation?
metals
ceramics
polymers
Benefits of sterilization with ethylene oxide gas
no radiation damage
surface treatment
