Selective Detection of an Infection Biomarker by an Osteo-Friend Scaffold: Development of a Multifunctional Artificial Bone Substitute

Abstract

Developments in three-dimensional (3D) printing technologies have led to many potential applications in various biomedical fields, especially artificial bone substitutes (ABSs). However, due to the characteristics of artificial materials, biocompatibility and infection remain issues. Here, multifunctional ABSs have been designed to overcome these issues by the inclusion of a biochemical modality that allows simultaneous detection of an infection biomarker by osteo-friend 3D scaffolds. The developed multifunctional scaffolds consist of calcium-deficient hydroxyapatite (CDHA), which has a similar geometric structure and chemical composition to human bone, and gold nanoparticles (Au NPs), which assists osteogenesis and modulates the fluorescence of labels in their microenvironment. The Au NPs were subsequently conjugated with fluorescent dye-labeled probe DNA, which allowed selective interaction with a specific target biomarker, and the fluorescent signal of the dye was temporally quenched by the Au NP-derived Förster resonance energy transfer (FRET). When the probe DNA unfolded to bind to the target biomarker, the fluorescence signal was recovered due to the increased distance between the dye and Au NPs. To demonstrate this sensing mechanism, a microbial oligonucleotide was selected as a target biomarker. Consequently, the multifunctional scaffold simultaneously facilitated osteogenic proliferation and the detection of the infection biomarker.

Gold nanoparticles: promising biomaterials for osteogenic/adipogenic regulation in bone repair

“…On account of their imaging and fluorescence characteristics, AuNPs can be functionalized to act as osteo-inductive agents and imaging agents for CT 55 and specific infection markers. 57 In terms of effectiveness in vitro and in vivo, AuNPs exhibit some unique advantages. Many studies have demonstrated the osteogenic promotion induced by AuNP materials in vitro, and most of them were conducted on human cells, while a small proportion was conducted on cells from small animals according to our tables, thus increasing the possibility of acquiring similar results in the human body.…”

“…Furthermore, 3D scaffolds with a uniform pore size were manufactured via the layer-by-layer extrusion of ceramic pastes utilizing calcium-deficient hydroxyapatite (CDHA). 57 Then, the CDHA scaffolds were combined with mercaptopropyltrimethoxysilane (MPTS) through silanization reaction. Subsequently, AuNPs were grown on the CDHA-MPTS scaffolds in situ and conjugated with target-specific probe DNAs, generating the final Au-scaffold sensor.…”

“…On account of their imaging and fluorescence characteristics, AuNPs can be functionalized to act as osteo-inductive agents and imaging agents for CT 55 and specific infection markers. 57…”