Zinc Doped Halloysite Cooperating with Polylactic Acid for Bone Regeneration

Abstract

Three-dimensional (3D) printing techniques have received considerable focus in the area of bone engineering due to its precise control in the fabrication of complex structures with customizable shapes, internal and external architectures, mechanical strength, and bioactivity. In this study, we design a new composition biomaterial consisting of polylactic acid (PLA), and halloysite nanotubes (HNTs) loaded with zinc nanoparticles (PLA+H+Zn). The hydrophobic surface of the 3D printed scaffold was coated with two layers of fetal bovine serum (FBS) on the sides and one layer of NaOH in the middle. Additionally, a layer of gentamicin was coated on the outermost layer against bacterial infection. Scaffolds were cultured in standard cell culture medium without the addition of osteogenic medium. This surface modification strategy improved material hydrophilicity and enhanced cell adhesion. Pre-osteoblasts cultured on these scaffolds differentiated into osteoblasts and proceeded to produce a type I collagen matrix and subsequent calcium deposition. 3D printed scaffolds formed from this composition possessed high mechanical strength and showed an osteoinductive potential. Furthermore, the external coating of antibiotics not only preserved the previous osteogenic properties of the 3D scaffold but also significantly reduced bacterial growth. Our surface modification model enabled the fabrication of a material surface that was hydrophilic and antibacterial, simultaneously, with an osteogenic property. The designed PLA+H+Zn may be a viable candidate for the fabrication of customized bone implants.

Gentamycin-loaded halloysite-based hydrogel nanocomposites for bone tissue regeneration: fabrication, evaluation of the antibacterial activity and cell response

“…In addition, these results propose that cell survival and differentiation are supported by the HNT-antibiotic based scaffolds in vitro. This is in good agreement with the previously published studies that GM encapsulated scaffolds maintained their osteogenesis and bone forming performance on hMSCs and pre-osteoblast cells [55]. Similarly, it was revealed that free GM at specific concentrations (6.26 and 9.65 µg ml −1 ) was safe for viability and osteogenic differentiation of SaOS-2 cells [56].…”

“…By the embedding of HNT, porosity declined to 71.5%. Studies have shown that adding HNT led to a high degree of interconnectivity for GEL composite scaffolds along with increasing crosslinking density for chitosan hydrogel, which is resulted in higher stiffness and surface roughness [39]. The density range between 0.14 and 1.10 g cm −3 is considered to be optimal for trabecular bone [40].…”

The fabrication of halloysite nanotube-based multicomponent hydrogel scaffolds for bone healing

“…Previous Studies reported that halloysite nanotubes promoted the stiffness of hydrogel scaffolds via decreasing the pore size. 33 The porosity of the nano-membranes containing HNT 3% mixed with different co-filler (Fe 3 O 4 and nHA) was nearly the same, about 70% which was lower than PCG scaffold. In parallel, the density enhanced by the increasing of the nano-fillers (HNT, nHA, and Fe 3 O 4 ) content increased (Figure 5).…”