Citotoxicidade de novas ligas a base de titânio visando aplicações biomédicas
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Data
2022-02-25
Autores
Corrêa, Dante Oliver Guim
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Editor
Universidade Estadual Paulista (Unesp)
Resumo
O titânio e suas ligas são utilizados em implantes ortopédicos e odontológicos devido às adequadas características de biocompatibilidade, elevada resistência à corrosão e ótima relação resistência mecânica/densidade, quando comparados a outras ligas metálicas usadas na área biomédica. Dentre as ligas de titânio utilizadas no Brasil e no mundo para implantes ortopédicos, a mais usada é a liga Ti-6Al-4V, uma vez que apresenta uma resistência mecânica bastante superior à do titânio comercialmente puro. Além disso, os implantes que estão presentes no mercado são suscetíveis a degradação por desgaste mecânico, corrosão ou tribocorrosão (ação conjunta de corrosão e desgaste mecânico), razão pela qual apresentam um tempo de vida útil relativamente curto. No entanto, a liga Ti-6Al-4V possui elementos considerados citotóxicos: o vanádio causa reações alérgicas em tecidos humanos e o alumínio está associado à desordens neurológicas a longo prazo. Sendo assim, buscas de novas ligas sem esses elementos estão sendo realizadas. Ligas contendo nióbio, zircônio, molibdênio e tântalo são as mais promissoras, já que esses elementos são considerados β-estabilizadores, não-tóxicos ou alergênicos. Portanto, a adição deles ao titânio altera sua microestrutura e propriedades mecânicas, podendo torná-lo mais eficiente como biomaterial. Além disso, é importante que esses novos materiais estimulem, ou não interfiram, no crescimento e proliferação celular. Testes preliminares podem ser efetuados a partir do sistema de cultura de células, em que é possível analisar minuciosamente eventos celulares e da matriz extracelular (MEC). Desta forma, o presente projeto tem como foco principal o estudo da citotoxicidade in vitro de novas ligas a base de titânio visando aplicações biomédicas. Os resultados obtidos demonstraram potencial primário para as novas ligas de titânio, que não apresentaram citotoxicidade.
Titanium and its alloys are used in orthopedic and dental implants due to their adequate biocompatibility characteristics, high corrosion resistance and excellent mechanical strength to density ratio, when compared to other metallic alloys used in the biomedical field. Among the titanium alloys used in Brazil and worldwide for orthopedic implants, the most used is the Ti-6Al-4V alloy, since it has a higher mechanical resistance than commercially pure titanium. In addition, implants that are on the market are susceptible to degradation due to mechanical wear, corrosion or tribocorrosion (the joint action of corrosion and mechanical wear), resulting in relatively short service life. However, the Ti-6Al-4V alloy has elements considered cytotoxic: vanadium causes allergic reactions in human tissues and aluminum is associated with long-term neurological disorders. Therefore, searches for new alloys without these elements are being carried out. Alloys containing niobium, zirconium, molybdenum and tantalum are the most promising, as these elements are considered β-stabilizers, non-toxic and non-allergenic. Therefore, their alloying to titanium alters its microstructure and mechanical properties, making it more efficient as a biomaterial. Furthermore, it is important that these new materials stimulate, or not interfere with, cell growth and proliferation. Preliminary tests can be carried out from the cell culture system, where it is possible to thoroughly analyze cellular and extracellular matrix (ECM) events. Thus, this project is focused on the study of the in vitro cytotoxicity of new titanium-based alloys aiming at biomedical applications. The results obtained showed primary potential for the new titanium alloys, which did not show cytotoxicity.
Titanium and its alloys are used in orthopedic and dental implants due to their adequate biocompatibility characteristics, high corrosion resistance and excellent mechanical strength to density ratio, when compared to other metallic alloys used in the biomedical field. Among the titanium alloys used in Brazil and worldwide for orthopedic implants, the most used is the Ti-6Al-4V alloy, since it has a higher mechanical resistance than commercially pure titanium. In addition, implants that are on the market are susceptible to degradation due to mechanical wear, corrosion or tribocorrosion (the joint action of corrosion and mechanical wear), resulting in relatively short service life. However, the Ti-6Al-4V alloy has elements considered cytotoxic: vanadium causes allergic reactions in human tissues and aluminum is associated with long-term neurological disorders. Therefore, searches for new alloys without these elements are being carried out. Alloys containing niobium, zirconium, molybdenum and tantalum are the most promising, as these elements are considered β-stabilizers, non-toxic and non-allergenic. Therefore, their alloying to titanium alters its microstructure and mechanical properties, making it more efficient as a biomaterial. Furthermore, it is important that these new materials stimulate, or not interfere with, cell growth and proliferation. Preliminary tests can be carried out from the cell culture system, where it is possible to thoroughly analyze cellular and extracellular matrix (ECM) events. Thus, this project is focused on the study of the in vitro cytotoxicity of new titanium-based alloys aiming at biomedical applications. The results obtained showed primary potential for the new titanium alloys, which did not show cytotoxicity.
Descrição
Palavras-chave
Biomateriais, Citotoxicidade, Biocompatibilidade, Ligas de titânio, Implantes artificiais, Biomaterials, Cytotoxicity, Biocompatibility, Nickel-titanium alloys, Implants