Células-tronco do próprio paciente cicatrizam córnea
Autor: Marcus Henrique | Publicado: 2014-12-27T18:39:00-02:00



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Tratar o embaçamento na visão
gerado por uma cicatriz na córnea pode ser tão simples quanto aplicar no local
da lesão células-tronco extraídas de uma pequena biópsia do outro olho.




Este
experimento teve sucesso com células humanas implantadas em camundongos, em um
teste realizado por pesquisadores da Universidade de Pittsburgh (EUA) e
publicado na revista Science Translational Medicine.




Apesar
dos&nbsp;inúmeros problemas levantados
pelos testes iniciais com tratamentos de células-tronco, a equipe acredita que
este estudo traz esperança de diminuir a necessidade de transplantes de córnea.




Células-tronco
oculares




Sayan
Basu e seus colegas já haviam desenvolvido uma técnica para a obtenção de&nbsp;células-tronco&nbsp;oculares a partir de pequenas biópsias
feitas na superfície do olho e em uma região entre a córnea e a esclera,
conhecida como limbo. A remoção de tecido dessa região cicatriza rapidamente
com pouco desconforto e sem interrupção da visão.




Depois de
coletar biópsias de olhos humanos em bancos de doação de órgãos, a equipe
ampliou o número de células em uma placa de cultura usando soro humano para
nutri-las. Eles realizaram vários testes para verificar se essas células eram,
de fato, células-tronco da córnea.




As
células-tronco humanas foram então implantadas em camundongos com lesões na
córnea. A equipe usou um gel de fibrina, uma proteína encontrada em coágulos de
sangue que é comumente utilizada como adesivo cirúrgico, para colar as células
no local da lesão.




Sem
rejeição




As
córneas danificadas dos camundongos cicatrizaram e ficaram claras novamente
quatro semanas após o tratamento, enquanto a visão dos animais não tratados
permaneceu nublada.




"Usando
as próprias células do paciente, retiradas por esse processo do olho não
atingido, poderia superar as preocupações com a rejeição [de
transplantes]," disse o Dr. Basu. "Isto pode ser muito útil,
particularmente em lugares que não têm bancos de tecido corneal para
transplante."




A equipe
já planeja testar a técnica em humanos.

Fonte: Diário da Saúde