Biomimetic Bone-like Hydroxyapatite by Mineralization on Supramolecular Porous Fiber Networks

Abstract

Hydroxyapatite (HA), the main inorganic component of bone tissue, is mineralized with collagen fibril scaffolds during bone formation. Inspired by the process, a self-assembled porous network architecture was designed and synthesized by using the 2-ureido-4[1H]-pyrimidone (UPy) modified glycerol molecule UPy-Gly, which was further utilized as a template for biomimetic mineralization. When incubated in simulated body fluid (SBF), the HA nucleus first formed in the holes of the template by the induction of hydroxyls on the surface, grew along the nanofibers, and fused with the template to fabricate hydroxyapatite composites (UPy-Gly/HA). Transmission electron microscopic observation demonstrates that the mineral clusters are accumulated by lamella-like nano hydroxyapatite and the elasticity modulus measured by atomic force microscopy is about 5.5 GPa, which is quite close to the natural cancellous bone tissue of human both in structure and in mechanical properties. The Cell Counting Kit 8 (CCK-8) assay of UPy-Gly and UPy-Gly/HA shows noncytotoxicity to mouse fibroblast L-929 cells. This bioinspired composite will be a promising material for potential use in bone tissue implantation and regeneration engineering.

Microphase separation of a quadruple hydrogen bonding supramolecular polymer: effect of the steric hindrance of the ureido-pyrimidone on their viscoelasticity

“…Therefore, the formation of the nano-bre structure of UPy dimer could be explained by the mechanism we investigated previously that the UPyurethan moiety self-assembled into distinct nano-bres with the p-p interaction of the conjugated structure and the lateral hydrogen bonding formed between urethan. 48 The nanober hard domains of polymers 1 and 2 appeared more distinct and densely packed compared with the nano-bers of polymers 3-5. Fig.…”

“…As the simplest substitution group, the methyl has little steric hindrance which would give no hinder to the formation of the nano-bre stacks. 48 With the increase of the steric hindrance of the substitution group at sixposition, the distinct and well-dened boundary of the nano-bre structure gradually became vague ( Fig. 1c-e), which indicated that the degree of phase separation decreased dramatically.…”

Eggshell Based Nano-Engineered Hydroxyapatite and Poly(lactic) Acid Electrospun Fibers as Potential Tissue Scaffold

“…However, the simplicity of experimental setup, low cost, the high porosity, and high interconnectivity of electrospun fibers makes them ideal tissue scaffolds [14–17]. HA nanoparticles are incorporated into the polymer matrix either through biomineralization of pristine polymer fiber mats or coelectrospinning of the polymer and the HA nanoparticles [4, 18]. The incorporation of most calcium phosphate ceramics into polymer nanocomposite electrospun fibers involves coelectrospinning of polymer containing calcium and phosphate precursors.…”

Honeycomb-like PLGA-b-PEG Structure Creation with T-Junction Microdroplets

“…Porous polymeric structures as an extracellular matrix (ECM) analogue provide a spatial conformation and orientation to cells and permits nutrient transport, fulfilling a pivotal role in tissue engineering [1][2] . The control of porosity and pore shape is crucial for the polymeric membranes and scaffolds since the size of the pores directs the cell and nutrition transport through the scaffold 3 .…”