In vitro and in vivo evaluation of bone formation using solid freeform fabrication-based bone morphogenic protein-2 releasing PCL/PLGA scaffolds

Abstract

The aim of this study was to develop novel polycaprolactone/poly(lactic-co-glycolic acid) (PCL/PLGA) scaffolds with a heparin-dopamine (Hep-DOPA) conjugate for controlled release of bone morphogenic protein-2 (BMP-2) to enhance osteoblast activity in vitro and also bone formation in vivo. PCL/PLGA scaffolds were prepared by a solid freeform fabrication method. The PCL/PLGA scaffolds were functionalized with Hep-DOPA and then BMP-2 was sequentially coated onto the Hep-DOPA/PCL/PLGA scaffolds. The characterization and surface elemental composition of all scaffolds were evaluated by scanning electron microscope and x-ray photoelectron spectroscopy. The osteoblast activities on all scaffolds were assessed by cell proliferation, alkaline phosphatase (ALP) activity and calcium deposition in vitro. To demonstrate bone formation in vivo, plain radiograph, micro-computed tomography (micro-CT) evaluation and histological studies were performed after the implantation of all scaffolds on a rat femur defect. Hep-DOPA/PCL/PLGA had more controlled release of BMP-2, which was quantified by enzyme-linked immunosorbent assay, compared with Hep/PCL/PLGA. The in vitro results showed that osteoblast-like cells (MG-63 cells) grown on BMP-2/Hep-DOPA/PCL/PLGA had significantly enhanced ALP activity and calcium deposition compared with those on BMP-2/Hep/PCL/PLGA and PCL/PLGA. In addition, the plain radiograph, micro-CT evaluation and histological studies demonstrated that the implanted BMP-2/Hep-DOPA/PCL/PLGA on rat femur had more bone formation than BMP-2/Hep/PCL/PLGA and PCL/PLGA in vivo.

How to use BMP-2 for clinical applications? A review on pros and cons of existing delivery strategies

“…Fibers with immobilized BMP-2 significantly induced osteogenic differentiation with a significant increase in ALP activity, calcium deposition and mRNA expression levels of osteocalcin and osteopontin compared to the unmodified PCL fibers [101]. A subsequent in vivo study demonstrated that the implanted BMP-2/Hep-DOPA/PCL/ PLGA scaffolds implanted into rat femur defects induced more bone formation compared to that of BMP-2/Hep/PCL/PLGA-and PCL/ PLGA scaffolds [102]. Similarly, BMP-2 has also been immobilized onto calcium coated chitosan scaffolds [103].…”

Rapid prototyping technology and its application in bone tissue engineering

“…These scaffolds had a fully interconnected structure, porosity of approximately 69.6%, and excellent cytocompatibility with MC3R3-E1 cells. Kim et al (2014) also used MDHS to prepare PCL/PLGA scaffolds combined with a heparindopamine conjugate for controlled release of BMP-2 to improve osteoblast activity. Low-temperature deposition modeling (LDM), robocasting/direct-write assembly, and 3D bioplotting remove the processes of heating and liquefying, and can add thermally sensitive biocomponents or cells into materials.…”

Stem Cell-Based Therapies for Osteoarthritis: From Pre-Clinical to Clinical Applications

“…Herein, MSC has to be cultured in the specific medium composed of the substituent known to stimulate and control these differentiations in vivo. These are mostly specific growth factors such as BMPs for osteocytes [32][33][34] and TGFs, BMPs, and FGFs for chondrocytes [35][36][37][38]. To optimize MSC differentiation, cells need to be put under the in vivo-like environment.…”

“…To optimize MSC differentiation, cells need to be put under the in vivo-like environment. Then MSC aimed to become osteocytes or chondrocytes will be cultured in 3D pellets [32][33][34][35][36][37][38] while differentiation to adipocytes will be performed in monolayer.…”