Novel sintering-free scaffolds obtained by additive manufacturing for concurrent bone regeneration and drug delivery: Proof of concept

resumo

Advances on the fabrication of sintering-free biphasic calcium phosphate (BCP)/natural polymer composite scaffolds using robocasting as additive manufacturing technique are presented in the present work. Inks with high amounts of BCP powders (45 vol%) containing different HA/beta-TCP ratios, in presence of crosslinked polymer, were successfully fine-tuned for extrusion by robocasting. The non-existence of sintering step opened the possibility to obtain drug loaded scaffolds by adding levofloxacin to the extrudable inks. The drug presence induced slightly changes on the rheological behaviour of the inks, more emphasized for the BCP compositions with higher amounts of beta-TCP, and consequently, on the microstructure and on the mechanical properties of the final scaffolds. The strong interaction of beta-TCP with chitosan difficult the preparation of suitable theological inks for printing. Drug delivery studies revealed a fast release of levofloxacin with a high burst of drug within the first 30 min. Levofloxacin loaded samples also presented bacteria growth inhibition ability, proving that antibiotic was not degraded during the fabrication process and its bactericidal efficacy was preserved. From the results obtained, the composite scaffolds containing higher amounts of HA (around 80% HA/20% beta-TCP) constitute a promising bi-functional synthetic bone substitute for simultaneous local bone regeneration and infection treatments.

palavras-chave

CALCIUM-PHOSPHATE CERAMICS; LEVOFLOXACIN; CHITOSAN; COMPOSITE; THERAPY; GENIPIN; IMPLANTATION; TEMPERATURE; FABRICATION; HYDROGELS

categoria

Materials Science

autores

Marques, CF; Olhero, SM; Torres, PMC; Abrantes, JCC; Fateixa, S; Nogueira, HIS; Ribeiro, IAC; Bettencourt, A; Sousa, A; Granja, PL; Ferreira, JMF

Grupos

G1 - Materiais Porosos e Nanossistemas
G3 - Materiais Eletroquímicos, Interfaces e Revestimentos
G5 - Materiais Biomiméticos, Biológicos e Vivos

Projectos

CICECO - Aveiro Institute of Materials (UID/CTM/50011/2013)

Desenvolvimento de biomateriais não sinterizáveis à base de fosfatos de cálcio com bi-funcionalidade: regeneração e tratamento de cancro ósseo (2BBone)

Projeto de Investigação Exploratória: Susana Olhero (IF/00951/2014)

agradecimentos

This study was financially supported by the projects of CICECO-Aveiro Institute of Materials, POCI-01-0145-FEDER-007679 (Ref. UID/CTM/50011/2013) University of Aveiro, and 2BBone (POCI-01-0145-FEDER-029940), financed by Operational Programme for Competitiveness and Internationalization (POCI/COMPETE 2020/FEDER) and national funds through the Portuguese Foundation for Science and Technology (FCT/MEC). C.F. Marques is grateful for the Grant SFRH/BD/78355/2011 from FCT. S.Olhero project IF/00951/2014 from FCT is also acknowledged. P.L. Granja and A. Sousa are grateful to funding by European Regional Development Fund (ERDF) through the COMPETE 2020-POCI, Norte Portugal Regional Operational Programme (NORTE 2020), under the PORTUGAL 2020 Partnership Agreement, and by Portuguese funds through FCT. iMED.ULisboa projects provided by FCT through Pest-UID/DTP/04138/2014 are also acknowledged. Authors would like to thank Micronsense - Metrologia Industrial (Leiria, Portugal) for the mu CT analysis.