Injectability of a bone filler system based on hydroxyapatite microspheres and a vehicle with in situ gel-forming ability

• Type: Article in International Scientific Journal
• Date: 2008

Authors

Serafim M Oliveira (Author) Other; Cristina C Barrias (Author) Other; Isabel F Almeida (Author) FFUP; Paulo C Costa (Author) FFUP; Maria Pena P Ferreira (Author) Other; Maria F Bahia (Author) Other; Mario A Barbosa (Author) FEUP

Journal

Title: Journal of Biomedical Materials Research - Part B Applied Biomaterials

Vol. 87B No. 1

Pages: 49-58

ISSN: 1552-4973

Publisher: Wiley-Blackwell

Indexing

ISI Web of Knowledge - 49 Citations

ISI Web of Science

Scopus - 52 Citations

COMPENDEX

Scientific classification

FOS: Engineering and technology > Environmental biotechnology

Other information

Authenticus ID: P-003-VVS

DOI: 10.1002/jbm.b.31066

Abstract (EN): The aim of this study was to test the injectability of a bone filler system based on the combination of ceramic microspheres with a gel-like vehicle, for noninvasive surgery. Porous hydroxyapatite microspheres with a uniform size and an average diameter of 535 +/- 38 mu m were prepared, and their compression strength and friability were tested. The sodium-alginate solution with a concentration of 7.25% (w/v) was used as the vehicle. To promote its in situ gelation, calcium carbonate and D-gluconic-S-lactone were added to the solution. Microspheres were mixed with the vehicle at different percentages (20-40 wt %). Gelation times in the range of 8-20 min, were obtained, depending on the formulation. Mixtures of HAp microspheres with alginate solution at 7.25% originating a gel in 11 min present an adequate handling time to perform an injection. Their injectability was evaluated using an injection device commonly employed in vertebroplasty surgical procedures, coupled to a texturometer in compression mode. Using an extrusion rate of 0.1 mm/s, the force required to extrude any of the mixtures tested was lower than 100 N. For an extrusion rate of I mm/s mixtures with 40 wt % of microspheres were very difficult to inject. Mixtures with 35 wt % of microspheres presented the best compromise between injectability and compression strength of the gelled system. MicroCT analysis revealed a homogeneous distribution of the microspheres inside the vehicle, as well as full interconnection of the intra-microspheres spaces. The compression strength for the gelled systems ranged from 80 kPa (gel itself) to 600 kPa (composite with 40 wt % of microspheres). (c) 2008 Wiley Periodicals, Inc.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 10