Self-Assembled type I collagen-apatite fibers with varying mineralization extent and luminescent terbium promote osteogenic differentiation of mesenchymal stem cells

This work explores in depth the simultaneous self¿assembly and mineralization of type I collagen by a base¿acid neutralization technique to prepare biomimetic collagen¿apatite fibrils with varying mineralization extent and doped with luminescent bactericidal Tb3+ ions. Two variants of the method are...

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Detalles Bibliográficos
Autores: Romero-Castillo, Ismael, López-Ruiz, Elena, Fernández-Sánchez, Jorge F., Marchal-Corrales, Juan Antonio, Gómez-Morales, Jaime
Tipo de recurso: artículo
Estado:Versión aceptada para publicación
Fecha de publicación:2021
País:España
Institución:Consejo Superior de Investigaciones Científicas (CSIC)
Repositorio:DIGITAL.CSIC. Repositorio Institucional del CSIC
OAI Identifier:oai:digital.csic.es:10261/276410
Acceso en línea:http://hdl.handle.net/10261/276410
Access Level:acceso abierto
Palabra clave:Apatite mineralization
hMSCs cell viability
hMSCs osteogenic differentiation
Self-assembly
Terbium
Type I-collagen
X-ray diffraction
Descripción
Sumario:This work explores in depth the simultaneous self¿assembly and mineralization of type I collagen by a base¿acid neutralization technique to prepare biomimetic collagen¿apatite fibrils with varying mineralization extent and doped with luminescent bactericidal Tb3+ ions. Two variants of the method are tested: base¿acid titration, a solution of Ca(OH)2 is added dropwise to a stirred solution containing type I collagen dispersed in H3PO4; and direct mixing, the Ca(OH)2 solution is added by fast dripping onto the acidic solution. Only the direct mixing variant yielded an effective control of calcium phosphate polymorphism. Luminescence spectroscopy reveals the long luminescence lifetime and high relative luminescence intensity of the Tb3+¿doped materials, while two¿photon confocal fluorescence microscopy shows the characteristic green fluorescence light when using excitation wavelength of 458 nm, which is not harmful to bone tissue. Cytotoxicity/viability tests reveal that direct mixing samples show higher cell proliferation than titration samples. Additionally, osteogenic differentiation essays show that all mineralized fibrils promote the osteogenic differentiation, but the effect is more pronounced when using samples prepared by direct mixing, and more notably when using the Tb3+¿doped mineralized fibrils. Based on these findings it is concluded that the new nanocomposite is an ideal candidate for bone regenerative therapy.