The tests used to determine biocompatibility of a material are used in regards to ISO 10993. These tests can include cytotoxicity, genotoxicity and irritation. These test if the material is poisonous to the cells or genes. They even test if the material will irritate the skin or body and if it destroys blood cells. The tests will differ depending on what material are you testing. For example if you reference the toxicity table you will see that the what type of material comes in contact with the body has an affect on what tests should be used. Then you would have to determine what part of the body it would come in contact with and finally how long it will be in contact with this part of the body. With these three boundaries you can narrow down to the certain tests you need to test the biocompatibility of the material.

To test the biocompatibility of a new material device you go through the ISO 10993­1 Test Matrix check list. There are several tests that needs to be preformed on the new material device. For example: cytotoxicity, carcinogenicity, genotoxicity, irritation and more. The new material must go through some of the tests, it will depend on what the new material is going to be used for. Is it going to be for skin, bone replacement, heart valve replacement...? The reason being is that the location in our body requires different stress, elasticity, durability, etc. because it go under different biological environments which the material must withstand. Testing toxicity is required for all material because the device that we are creating are intended to improve and help, not to cause harm or kill.

Biocompatibility testing must be performed in accordance to ISO 10993 and other FDA relevant standards.The ISO10933 table provides a series of tests that can be used to test devices based on which category they fall under.With that being said, biocompatibility testing occurs in the forms of cytotoxicity, irritation, hemocompatibility, sensitization, carcinogenicity, or any other biological effect listed on the ISO-10993-1 toxicity test matrix. Moreover, Once the biomaterial is tested for all tests depending on the category, it can be used for clinical trials after getting approval. Different applications will require different types of testing. The test will depend on the material used and the process that was performed to manufacture the final product. Other tests may have to be performed for effects such as genotoxicity if the device is more invasive.

To begin, I believe before running any type of test, determining the molecular compound, as well as the intended application, of the material is the top priority. For example, titanium, certain ceramics, and synthetic polymers can all be biocompatible but won't all necessarily be appropriate for multiple biomedical applications. (e.g. titanium is best suitable for dental implants due to their osseointegration properties, ceramics are best suitable for bone-related medical solutions, etc). Whether or not this can be determined, a good course of action to test this new material would have to involve ex-vivo experiments. Observing the degradation of the material over time in different tissue environments, for instance, would be crucial in determining whether or not this material can last in a human body without degrading. If it were to be assumed that this material is meant to degrade overtime, then examination of the resulted particles and determining if they are harmless throughout the entire body would have to be made. If the molecular composition of the material can be determined and ex-vivo tests have been made, en-vivo tests should naturally be made if deemed plausible. This will provide a great amount of information that ex-vivo tests cannot provide. The properties that can be determined through these tests include the Carcinogenicity, Immunogenicity, Toxicity, and Teratogenicity of the material.

Apart from FDA regulations and ISO 10993, it is equally important to test the material understand the different conditions it will undergo. For example, if an implant is meant to bear load (orthopedic implant), it would be beneficial to know the tolerances and the maximum limit it can handle, as well as extreme cases such as a such twisting motion or low squat position (for hip implants) such considerations will help determine the limitations of the material.

As others students stated, referencing the Toxicity Table from ISO 10993 should give a general idea of tests needed prior to clinical trial phase. Ultimately the test needed will depend on the expected functionality of the medical devices. For instance, in the case of orthopedic implants, it is important to measure maximal load and stress level the implant can support without being subjected to deformation. It might also be beneficial how the biomaterial will react to other parameters such as variation in heat, twisting motion or pH value. Others bioengineered products might require similar and additional testing. For instance, for a device that interacts permanently with bones should be texted for genotoxicity, carcinogenicity, cytotoxicity, implantation, sensitization, and chronic toxicity, whereas tests for medical devices that interact only with the will probably don't require carcinogenicity or chronic toxicity.

Before a biomaterial goes into the human body, it must first be tested for biocompatibility. These various tests include cytotoxicity, genotoxicity, systemic toxicity, toxikokinetics, hemocompatibility, Irritation. The material must also be tested for stability. In most cases, in vitro and in vivo testing is used. 

If the device is required to be on the surface of the skin, it is important to take into account the possibilities of skin irritation, allergies, etc. If the device will be implanted in the body, you don't want the material to negatively impact the cells (cytotoxicity), genes (genotoxicity), etc. This is why these tests are important to do before clinical trials.

When evaluating the biocompatibility of a prospective biomaterial, the types of tests required for initial evaluation include cytotoxicity, sensitization, irritation, genotoxicity, implantation, and carcinogenicity tests, among others. Different types of applications would require different types or combinations of tests. For example, a material used in a temporary skin patch wouldn’t not require the same types of biocompatibility testing as those used in a permanent bone implant.

Biocompatibility tests should be completed according to ISO 10993-1 thru 18 before clinical trials. The tests include Cytotoxicity, Genotoxicity, Irritation, Systemic Tox, Hemocompatibility, Implantation, Toxikokinetics. According to the different application sites of biomaterials, there will be slight differences in testing.

First of all the biocompatibility testing should be carried out as per the ISO 10993 standards prior to  clinical studies of the device or the material. The ISO 10993 has parts from 1 through 18 has the various regulations listed under them for testing the biocompatibility. The various tests that could be run as mentioned in week 3 of the class include cytotxicity, genotoxicity, irritation, systemic toxicity, hemocompatibility, implantation, toxikokinetics, etc. The ISO 10993-1 has the test matrix that shows which tests are to be performed depending  on the body contact to the implant and the duration of exposure. The time periods could be limited, prolonged and permanent. This could b followed by the ADME testing and stability testing of the device and each component of the device. 

Depending on the use for the device material of the device will be checked for biocompatibility, followed by checking if the material is degradable or non-biodegradable and also checking if the Young's modulus of the implant matches with that of  tissue/bone with which the implant will be in contact with.

In order to test the initial biocompatibility of the new biomaterial, I would use the ISO 10993-1 Test Matrix. Different tests like cytotoxicity, sensitization, irritation, systemic toxicity, genotoxicity, and hemocompatibility tests will be performed based on the body contact level and exposure duration. For a neural biomaterial like platinum used in implanted neural electrodes, cytotoxicity, sensitization, irritation, systemic toxicity, genotoxicity, sub-chronic toxicity, and implantation tests must be performed. Implanted neural electrodes may be used for deep brain stimulation therapy to treat conditions like Parkinson's, Dystonia, and Mutiple Sclerosis. For longer therapy sessions, additional chronic toxicity and carcinogenicity tests may be required. For external electrodes used for transcranial direct current stimulation in shorter sessions, however, sub-chronic toxicity and implantation tests will not be required.

Reference: https://www.aans.org/en/Patients/Neurosurgical-Conditions-and-Treatments/Deep-Brain-Stimulation

In order to test this new bio-material, I would perform testing based on the ISO 10993 international standard. This standard has 18 parts that evaluate how a device will be used and which tests to perform. It includes how the device will be located in the body, such as an implant, a surface device, or an external communication device like a TENS unit. 

It also has an indication of which tissues it will contact, whether it be blood, tissue, bone, or other areas. There is also a category for expected duration of use within the body, whether temporary or permanent. The tests include cytotoxicity, sensitization, irritation, various forms of toxicity, hemocompatibility, and more. These tests may or may not be compatible, depending on the application. A metal for a stent would be incompatible for use with a breast plant. 

@quanzi What specifically do you mean when you say that a "metal for a stent would be incompatible for use with a breast plant"?

I am referring to the material having the desired interface with the tissue. Breast tissue is soft and fluid. A biomaterial acting  as an implant must be fluid in nature as well, to match the interface of the breast tissue. 

Other respondents have already emphasized how biocompatibility is cover by ISO 10993, so I will dig right into how I evaluate new biomaterial in my previously failed dialysis product from five years ago.  There is an inventor that I met from Ohio, where I grew up, and he developed tubing that could be used for IVs, catheters and dialysis machines that is less prone to the development of infections and was described as being "not as uncomfortable" by the approximately 60 people that he had pilot-tested. I would run biocompatibility tests for the limited but repeated use of the tubing, looking at its correlation to chronic inflammation, sensitization and infection (toxicity).  Of specific interest would be its compatibility with the fistulas that were surgically implanted into the arms of a dialysis patient.

During dialysis the patient's blood is transported out and filtered using a dialysate solution.  My proposed dialysis process recreates a dialysate solution with a non-water base comprised of electrolytes, so this new dialysate solution would have to be examined for its hemocompatibility, as well as the infusion of a natural occurring derivative into the blood before re-entering the body. This derivative is comparable to ozonated blood, which has generated positive research results in recent years, in spite of the research community and FDA historically labeling medical ozone and ozone therapy as medically toxic and scientifically unsubstantiated. 

In closing, my proposed dialysis process would involve the examination of its biomaterial surface interaction and the merits of the re-engineered dialysis machine in meeting federal regulatory and safety standards.