Agnes

Your question is not clearly understood. from your second part, it looks like you are asking: will biomaterials necessarily give protection from UV waves?

If so, the answer would be it depends. Biomaterials may do protection but they may also degrade and go off. therefore the protection is not sustained.

It really depends

Yes they need. Example: when biopolymer is exposed on UV it may comes to monomerization - the aging process.

All organic materials are sensitive to UV. When exposed outdoor, and especially to direct sunlight, they need a protection. The first problem is the discoloration, or at least the change of colour. This is just a visual problem. But later starts a slow decomposition. Opaque materials are much less sensitive, as the UV can not penetrate very deep, therefore only the outer surface is altered (becomes rough and changes its colour).

Alain

Two questions could be concluded:

-UV effect on biomaterials: It can have various effect depend on your biomaterial, for example cross-linking is one of the effects.

-Biomaterial protection against UV

Which kind of biomaterials are you talking about? Ceramics? Polymers? Composites?

Polymeric biomaterials are no more prone to oxidative stresses induced by UV radiation exposure than other kind of polymers. But, as their molar masses tend to be smaller, the impact of the radiation upon mechanical properties, to cite one, should be more pronounced. Besides, depending on the chemical nature of the biopolymer, unwanted reactions may occur because of the exposure to UV. It is advised to run preliminar analyses on such biomaterials prior to their use, employing UV chambers and taking the materials' mechanical properties before and after the exposure for comparison.

Regards.