Using materials that can guide endogenous regeneration is a strategy that is becoming increasingly popular in the tissue engineering field. Due to their unique properties and flexibility in design, nanoparticles (NPs) can be used and combined to create intelligent multifunctional structures, improving tissue and organ engineering .
Nanoparticles can help to upgrade various properties of a 3D printing construct, including mechanical stability, biocompatibility, biological activity, and providing antimicrobial and antitumor properties. Moreover, the low toxicity of NPs and the high precision and clarity of imaging to detect cells in a non-invasive way when these particles are associated with them are factors that indicate the benefits that can be brought from the association of NPs with stem cells for tissue engineering [1,2].
The general concept of a nanoparticle is a material with the diameter ranging between 1 to 100 nm. The size and morphology of NPs influence their physicochemical properties and affect particles’ cell absorption rates and how they interact with various biological tissues, which is different from other bulk materials .
NPs can be prepared with various materials, such as ceramics, metals, natural and synthetic polymers. Depending on the intended application, a specific type of NP may be more suitable due to its composition and distinct characteristics, such as penetration ability and surface area .
Figure 1: Examples of different types of nanoparticles .
In 2014, Gao and his team conducted a study focused on evaluating how bioactive ceramic nanoparticles can stimulate the osteogenesis of human mesenchymal stem cells derived from bone marrow (hMSCs) printed on a poly (ethylene glycol) dimethacrylate (PEGDMA) structure. The hMSCs suspended in PEGDMA were co-printed with bioactive glass nanoparticles (BG) and hydroxyapatite (HA), and the viability of making a bone-like tissue was demonstrated. The hydroxyapatite and bioglass NPs were extremely useful for bone tissue engineering. Their presence in the scaffold significantly stimulated the osteogenic differentiation of hMSCs and osteogenic ECM production with minimal cellular toxicity .
Using cell sheet technology, Zhang et al. (2021) observed the effect of gold nanoparticles (AuNPs) on the differentiation of periodontal ligament stem cell (PDLSC) sheets and investigated their potential mechanism of action. The researchers concluded that AuNPs could promote osteogenic differentiation of PDLSC sheets through the positive regulation of bone-related protein expression and mineralization. AuNPs also promoted bone regeneration of PDLSC sheets in ectopic models. This study determined gold nanoparticles’ role in regulating osteogenic differentiation and bone regeneration, providing a new strategy to promote the repair of alveolar bone defects in future research .
Figure 2: (A) Scheme for the in vitro study and (B) the in vivo study of the effect of gold nanoparticles (AuNPs) on the differentiation of periodontal ligament stem cell (PDLSC) sheets .