LaB6 surface chemistry-reinforced scaffolds for treating bone tumors and bone defects

Abstract

Bone tumors may lead to osteoporosis. It is of great significance to fabricate functional scaffolds for treating bone tumor, osteoporosis and repairing bone defects. In this study, LaB6 micro-nanoparticles/poly(d,l-lactide)-modified β-tricalcium phosphate scaffolds (TCP-PDLLA-LB) were successfully prepared. The LaB6 surface chemistry-reinforced TCP-PDLLA-LB scaffolds were endowed with the following excellent properties: (1) the enhanced mechanical strength. The TCP-PDLLA-5LB scaffolds possessed higher compression resistant capacity than TCP scaffolds owing to the strong adhesive property of PDLLA that bound the LaB6 micro-nanoparticles and scaffolds tightly; (2) the excellent photothermal performance. TCP-PDLLA-LB scaffolds presented distinct photothermal property because of localized surface plasmon resonance effect of LaB6 micro-nanoparticles when exposed to the near-infrared (NIR) light (wavelength: 808nm) and it was flexibly controllable through changing the quantity of LaB6 micro-nanoparticles, power density of NIR light and environmental humidity; (3) the excellent biological properties in vitro. When culturing with saos-2 bone tumor cells, the TCP-PDLLA-5LB scaffolds effectively killed the saos-2 cells through adjusting power density of NIR light, irradiation duration time of NIR light and irradiation times of NIR light. Additionally, the TCP-PDLLA-5LB scaffolds were able to release bioactive ions which were beneficial to the in vitro osteogenesis of rabbit bone marrow stromal cells (rBMSCs) by supporting the attachment and proliferation of rBMSCs as well as promoting the expressions of osteogenic genes BMP2, RUNX2 and COL 1; and (4) the abilities of effectively ablating bone tumors and supporting bone tissue regeneration in vivo. The bone tumor tissues were significantly ablated and suppressed through hyperthermia due to the existence of LaB6 micro-nanoparticles on the scaffolds. Simultaneously, TCP-PDLLA-5LB scaffolds implanted in bone defects effectively helped new bone formation regardless of NIR light irradiation. In conclusion, LaB6 surface chemistry-reinforced scaffolds possess the dual functions of ablating bone tumor and repairing bone defects, which offers a promising therapy strategy for tumor/disease-related bone tissue engineering.