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Freeze casting to engineer gradient porosity in hydroxyapatite-boron nitride nanotube composite scaffold for improved compressive strength and osteogenic potential. J Mech Behav Biomed Mater 2024 Feb;150:106283

Date

12/05/2023

Pubmed ID

38048712

DOI

10.1016/j.jmbbm.2023.106283

Scopus ID

2-s2.0-85178598068 (requires institutional sign-in at Scopus site)   18 Citations

Abstract

Graded porosity plays a crucial role in scaffolds for bone tissue engineering as it facilitates vital processes such as nutrient diffusion, cellular infiltration, and tissue integration. This paper explores the utilization of freeze casting (FC) as a technique to generate composite scaffolds comprising hydroxyapatite (HA) reinforced with 1D-boron nitride nanotubes (BNNTs) featuring graded porosity and improved compressive strength. Comparative studies were conducted using FC at room and sub-zero temperatures to assess the influence of temperature gradient and heat transfer rate on the production of gradient and aligned porosity in HA-BNNT composites. The FC process with a prolonged thermal gradient facilitated the creation of aligned pores in the HA-BNNT, exhibiting a wide distribution of 60% porosity ranging from 1 to 30 μm. Adding high strength 1 vol% BNNT reinforcement resulted in a remarkable 50% enhancement in compressive strength compared to the control sample. Osteoblasts seeded on the HA-BNNT substrate exhibited significantly higher alkaline phosphate activity, indicating accelerated mineralization compared to the control sample. Gradient porosity and wide pore distribution in the HA-BNNT scaffolds promoted osteogenic activities. Overall, the demonstrated FC processing technique and BNNT addition hold great potential for developing functional and biomimetic scaffolds that can effectively promote tissue regeneration, leading to improved clinical outcomes in bone tissue engineering applications.

Author List

Thomas T, Bakhshiannik A, Nautiyal P, Hutcheson JD, Agarwal A

Author

Amirala Bakhshiannik PhD, MS Postdoctoral Researcher 4 in the Physiology department at Medical College of Wisconsin




MESH terms used to index this publication - Major topics in bold

Biocompatible Materials
Boron Compounds
Compressive Strength
Durapatite
Nanotubes
Porosity
Tissue Engineering
Tissue Scaffolds