Optimized bone regeneration based on sustained release from three‐dimensional fibrous PLGA/HAp composite scaffolds loaded with BMP‐2

Abstract

Contemporary treatment of critical bone defect remains a significant challenge in the field of orthopedic surgery. Engineered biomaterials combined with growth factors have emerged as a new treatment alternative in bone repair and regeneration. Our approach is to encapsulate bone morphogenetic protein-2 (BMP-2) into a polymeric matrix in different ways and characterize their individual performance in a nude mouse model. The main objective of this study is to examine whether the PLGA/HAp composite fibrous scaffolds loaded with BMP-2 through electrospinning can improve bone regeneration. The hypothesis is that different loading methods of BMP-2 and different HAp contents in scaffolds can alternate the release profiles of BMP-2 in vivo, therefore modify the performance of scaffolds in bone regeneration. Firstly, mechanical strength of scaffolds and HAp nanoparticles distribution in scaffolds were investigated. Secondly, nude mice experiments extended to 6 weeks were carried out to test the in vivo performance of these scaffolds, in which measurements, like serum BMP-2 concentration, ALP activity, X-ray qualification, and H&E/IHC tissue staining were utilized to monitor the growth of new bone and the changes of the corresponding biochemical parameters. The results showed that the PLGA/HAp composite scaffolds developed in this study exhibited good morphology/mechanical strength and HAp nanoparticles were homogeneously dispersed inside PLGA matrix. Results from the animal experiments indicate that the bioactivity of BMP-2 released from the fibrous PLGA/HAp composite scaffolds is well maintained, which further improves the formation of new bone and the healing of segmental defects in vivo. It is concluded that BMP-2 loaded PLGA/HAp composite scaffolds are promising for bone healing.

Selective laser sintering fabrication of nano-hydroxyapatite/poly-ε-caprolactone scaffolds for bone tissue engineering applications

“…Hence HA has a strong capacity to absorb BMP-2. Studies by Fu et al 43 and Jeon et al 44 also showed that, after addition of HA, the ability of the material to facilitate sustained release of BMP-2 was significantly improved. This is consistent with our BMP-2 data.…”

In VitroandIn VivoStudies of BMP-2-Loaded PCL–Gelatin–BCP Electrospun Scaffolds

“…[39][40][41] However, BMP-2 tends to disperse rather than act locally when incorporated into the human body. Therefore, BMP-2 must be compounded with a carrier to control its release over an extended time period.…”

Biocompatibility of differently proportioned HA/PLGA/BMP-2 composite biomaterials in rabbits

“…Rabbit femurs, a well-established model of bone tissue defects (Fu et al, 2008;Wu et al, 2010), were implanted with the composite biomaterials in this study.…”