Influence of low contents of superhydrophilic MWCNT on the properties and cell viability of electrospun poly (butylene adipate-co-terephthalate) fibers

Abstract

The use of poly (butylene adipate-co-terephthalate) (PBAT) in tissue engineering, more specifically in bone regeneration, has been underexplored to date due to its poor mechanical resistance. In order to overcome this drawback, this investigation presents an approach into the preparation of electrospun nanocomposite fibers from PBAT and low contents of superhydrophilic multi-walled carbon nanotubes (sMWCNT) (0.1-0.5wt.%) as reinforcing agent. We employed a wide range of characterization techniques to evaluate the properties of the resulting electrospun nanocomposites, including Field Emission Scanning Electronic Microscopy (FE-SEM), Transmission Electronic Microscopy (TEM), tensile tests, contact angle measurements (CA) and biological assays. FE-SEM micrographs showed that while the addition of sMWCNT increased the presence of beads on the electrospun fibers' surfaces, the increase of the neat charge density due to their presence reduced the fibers' average diameter. The tensile test results pointed that sMWCNT acted as reinforcement in the PBAT electrospun matrix, enhancing its tensile strength (from 1.3 to 3.6MPa with addition of 0.5wt.% of sMWCNT) and leading to stiffer materials (lower elongation at break). An evaluation using MG63 cells revealed cell attachment into the biomaterials and that all samples were viable for biomedical applications, once no cytotoxic effect was observed. MG-63 cells osteogenic differentiation, measured by ALP activity, showed that mineralized nodules formation was increased in PBAT/0.5%CNTs when compared to control group (cells). This investigation demonstrated a feasible novel approach for producing electrospun nanocomposites from PBAT and sMWCNT with enhanced mechanical properties and adequate cell viability levels, which allows for a wide range of biomedical applications for these materials.

<p>Biological response of chemically treated surface of the ultrafine-grained Ti&ndash;6Al&ndash;7Nb alloy for biomedical applications</p>

“…ALP activity was carried out after 14 days. The experimental procedure was the same reported in Rodrigues et al 26 The proposed manufacturer's procedure protocol was used (LabstestDignostica, Belo Horizonte, BR). The ALP assay was realized in triplicate.…”

An overview on properties and applications of poly(butylene adipate‐co‐terephthalate)–PBAT based composites

“…PBAT is a synthetic polymers based on fossil resources, 100% biodegradable, with high elongation at break and very flexible [24]. This synthetic BP is prepared by transterification reaction under controlled conditions, and therefore generally exhibit predictable and reproducible properties [14].…”

PDLLA honeycomb-like scaffolds with a high loading of superhydrophilic graphene/multi-walled carbon nanotubes promote osteoblast in vitro functions and guided in vivo bone regeneration

“…In this context, the modification of polymeric surfaces using carbon nanotubes (CNT) has been demonstrated to be an excellent approach to achieve the desired physico-chemical, mechanical and biological properties [15][16][17]. Moreover, the use of plasma-functionalized CNT has been greatly highlighted as a feasible way to increase the oxygen functionalities, such as \ \C_O\ \OH, \ \OH, \ \C_O and \ \C\ \O; therefore, a significant increase in the polymer matrix-CNT adhesion interface is achieved when plasma-modified CNT are used instead of pristine-CNT [10,17,18].…”