Hydroxyapatite reinforced collagen scaffolds with improved architecture and mechanical properties

[Display omitted] Hydroxyapatite (HA) reinforced collagen scaffolds have shown promise for synthetic bone graft substitutes and tissue engineering scaffolds. Freeze-dried HA–collagen scaffolds are readily fabricated and have exhibited osteogenicity in vivo, but are limited by an inherent scaffold ar...

Full description

Saved in:
Bibliographic Details
Published in:Acta biomaterialia 2015-04, Vol.17, p.16-25
Main Authors: Kane, Robert J., Weiss-Bilka, Holly E., Meagher, Matthew J., Liu, Yongxing, Gargac, Joshua A., Niebur, Glen L., Wagner, Diane R., Roeder, Ryan K.
Format: Article
Language:English
Subjects:
Adipose Tissue - cytology
Adipose Tissue - metabolism
Animals
Architecture
Bioactivity
Biocompatibility
Biocompatible Materials - chemistry
Biomedical materials
Bone Transplantation
Cattle
Collagen
Collagen - chemistry
Collagens
Durapatite - chemistry
Freezing
Humans
Hydroxyapatite
Mechanical properties
Neovascularization, Physiologic
Osteogenesis
Osteoinduction
Paraffin - chemistry
Powders
Pressure
Reinforcement
Scaffold
Scaffolds
Stress, Mechanical
Tissue Engineering - methods
Tissue Scaffolds
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:[Display omitted] Hydroxyapatite (HA) reinforced collagen scaffolds have shown promise for synthetic bone graft substitutes and tissue engineering scaffolds. Freeze-dried HA–collagen scaffolds are readily fabricated and have exhibited osteogenicity in vivo, but are limited by an inherent scaffold architecture that results in a relatively small pore size and weak mechanical properties. In order to overcome these limitations, HA–collagen scaffolds were prepared by compression molding HA reinforcements and paraffin microspheres within a suspension of concentrated collagen fibrils (∼180mg/mL), cross-linking the collagen matrix, and leaching the paraffin porogen. HA–collagen scaffolds exhibited an architecture with high porosity (85–90%), interconnected pores ∼300–400μm in size, and struts ∼3–100μm in thickness containing 0–80vol% HA whisker or powder reinforcements. HA reinforcement enabled a compressive modulus of up to ∼1MPa, which was an order of magnitude greater than unreinforced collagen scaffolds. The compressive modulus was also at least one order of magnitude greater than comparable freeze-dried HA–collagen scaffolds and two orders of magnitude greater than absorbable collagen sponges used clinically. Moreover, scaffolds reinforced with up to 60vol% HA exhibited fully recoverable elastic deformation upon loading to 50% compressive strain for at least 100,000 cycles. Thus, the scaffold mechanical properties were well-suited for surgical handling, fixation, and bearing osteogenic loads during bone regeneration. The scaffold architecture, permeability, and composition were shown to be conducive to the infiltration and differentiation of adipose-derive stromal cells in vitro. Acellular scaffolds were demonstrated to induce angiogenesis and osteogenesis after subcutaneous ectopic implantation by recruiting endogenous cell populations, suggesting that the scaffolds were osteoinductive.
ISSN:1742-7061
1878-7568
DOI:10.1016/j.actbio.2015.01.031