Characterization of the Physical Properties and Biocompatibility of Polybenzoxazine-Based Aerogels for Use as a Novel Hard-Tissue Scaffold

Abstract

The process to successfully synthesize polybenzoxazine (PBO)-based aerogels has recently been optimized; however, the biocompatibility of these materials has never been investigated. PBO is synthesized from bisphenol A and aniline, which are both precursors to many commonly used biomaterials, including polyurethane. Surface-wise these new aerogels resemble the innate extracellular matrix of bone and if these new aerogels exhibit acceptable biocompatibility, they may be used as a scaffold for bone tissue engineering. Here, we aimed to characterize some of the physical properties of PBO aerogels, PBO aerogels co-polymerized with resorcinol and formaldehyde (RF) and their conversion to carbon aerogel, while determining the compatibility of all of these materials towards human osteoblasts. Biocompatibility was determined with a live/dead cell cytotoxicity assay, a metabolic activity assay, alkaline phosphatase activity and osteocalcin production, after incubation with PBO-based aerogels for up to 5 days. PBO aerogels co-polymerized with RF tended to have a low density, porosity and elastic modulus and provided the weakest substrate for bone cell growth. PBO-derived carbon aerogels tended to have a high density, a large porosity and improved mechanical properties and provided the best substrate for bone cell growth. These results suggest that PBO based carbon aerogels have a suitable biocompatibility towards osteoblasts and that they may be able to be used for bone tissue engineering scaffolds.

Synthesis and biomedical applications of aerogels: Possibilities and challenges

“…Recent studies have aimed to address the biocompatibility of various aerogels with different cell types, such as chitosan-silica hybrid aerogel with red blood cells [196], wollastonite aerogels with simulated body fluids [53], polyurea cross-linked silica aerogel [195] and N3300 A polyurea aerogels [194] toward vascular endothelial cells, red blood cells, and plasma platelets. Recently, Rubestein et al [50] have studied the basic biocompatibility of series of aerogels out of poly benzoxazine (PBO), PBO-RF co-polymer and their carbon species from the pyrolysis process. Since target biomedical application of this aerogel was a scaffold for tissue engineering of bone, the biocompatibility of aerogels toward human osteoblasts with performing series of cytotoxicity assay namely a live/dead cell assay, a metabolic activity assay, alkaline phosphatase activity and osteocalcin production have been studied.…”

“…[15,16]. Herein, the unique properties of the existing aerogels such as low density, high porosity and surface area, high mechanical strength together with a versatility of the sol-gel chemistry play important roles [50,197].…”

Glycated Albumin and Pathological Shear Stress Alters Endothelial Cell Thrombogenic Potential, Pro-Inflammatory State and Cytoskeletal Dynamics

“…A standard 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl tetrazolium bromide (MTT) assay was conducted to document that metabolic activity via mitochondrial dehydrogenase of endothelial cells [16,19]. After shear stress application, endothelial cells were incubated with reconstituted MTT reagent for 3 hours.…”

Polybenzoxazine-Based Nanofibers by Electrospinning

“…Generally, it is difficult to obtain nanofibers from monomers or small molecules because chain entanglement and overlapping are the key factors for the formation of nanofibers during the electrospinning process. Therefore PAN, which is an ideal blend material because of its high melting temperature [22] and good miscibility with the P-a monomer, was used as the carrier matrix, and it was aimed at improving the practical application of polybenzoxazine as superhydrophobic fibrous mats. The total concentration of PAN and P-a was maintained at 10% in the solution, and the PAN:P-a weight fractions (100:0, 70:30, 50:50, 30:70, and 0:100) were varied to produce PAN/P-a hybrid fibers by electrospinning.…”

“…Polybenzoxazine is a new, developing phenolic-type thermoset resin that has attracted much attention in recent years because of its outstanding properties, and the different forms of polybenzoxazine (such as bulk [1][2][3][4][5], film [6][7][8][9][10][11][12][13][14][15][16][17][18][19], aerogel [20][21][22][23][24][25], and porous membranes [26,27]) and their various applications have been studied extensively. At the same time, production of nanofibers from polybenzoxazine resins and incorporation of the polybenzoxazines into the other polymeric nanofibers for the functionalization and enhancement of the existing properties is a developing area.…”