Effect of sodium chloride as a porogen agent in mechanical properties of PLGA/HA nanocomposite scaffolds

In this study, the novel poly (lactic-co-glycolic acid)-Hydroxyapatite nanoparticles (PLGA/HA) nanocomposite scaffolds were fabricated with solvent casting and particulate leaching (SCPL) method. The role of sodium chloride (NaCl) particles with diameters of 250-400 μm as porogen agent in the mechanical strength of the produced scaffolds was evaluated. The prepared scaffolds were characterized using Fourier transform infrared (FT-IR), X-ray diffraction (XRD), scanning electron microscopy (SEM), thermal gravimetric analysis (TGA) and compressive tests. The results showed the high compressive strength and homogenous porous structures for PLGA/HA nanocomposite scaffolds compared to pure PLGA due to the presence of HA nanoparticles in nanocomposites. Furthermore, the compressive strength of nanocomposite scaffolds increased by varying the weight ratio of hydroxyapatite nanoparticles to polymer (0, 20, 40 wt%) at constant salt ratio and decreased by increasing the weight ratio of salt particles to polymer from 1 to 3 wt% due to more porosity in nanocomposite scaffolds. These results confirmed that not only the nanocomposite scaffolds exhibited high mechanical properties, homogenous structures, as well as good porosity but also, they could be useful for bone tissue application.

Enhancing Cell Proliferation and Osteogenic Differentiation of MC3T3-E1 Pre-osteoblasts by BMP-2 Delivery in Graphene Oxide-Incorporated PLGA/HA Biodegradable Microcarriers

Lack of bioactivity has seriously restricted the development of biodegradable implants for bone tissue engineering. Therefore, surface modification of the composite is crucial to improve the osteointegration for bone regeneration. Bone morphogenetic protein-2 (BMP-2), a key factor in inducing osteogenesis and promoting bone regeneration, has been widely used in various clinical therapeutic trials. In this study, BMP-2 was successfully immobilized on graphene oxide-incorporated PLGA/HA (GO-PLGA/HA) biodegradable microcarriers. Our study demonstrated that the graphene oxide (GO) facilitated the simple and highly efficient immobilization of peptides on PLGA/HA microcarriers within 120 min. To further test in vitro, MC3T3-E1 cells were cultured on different microcarriers to observe various cellular activities. It was found that GO and HA significantly enhanced cell adhesion and proliferation. More importantly, the immobilization of BMP-2 onto the GO-PLGA/HA microcarriers resulted in significantly greater osteogenic differentiation of cells in vitro, as indicated by the alkaline phosphate activity test, quantitative real-time polymerase chain reaction analysis, immunofluorescence staining and mineralization on the deposited substrates. Findings from this study revealed that the method to use GO-PLGA/HA microcarriers for immobilizing BMP-2 has a great potential for the enhancement of the osseointegration of bone implants.

Mineralization of a superficially porous microsphere scaffold via plasma modification

Novel porous mineralization layers were obtained on scaffolds. The plasma process could enhance the bonding force between apatite and the substrate surface.

Photo-immobilization of bone morphogenic protein 2 on PLGA/HA nanocomposites to enhance the osteogenesis of adipose-derived stem cells

Poly(lactide-co-glycolide) and nano-hydroxyapatite composites are surface-modified with BMP-2 via photo-reactive gelatin to make the composites exhibit excellent bioactivities for the adhesion, proliferation and osteogenic differentiation of ADSCs.

Osteoblast compatibility of minerals substituted hydroxyapatite reinforced poly(sorbitol sebacate adipate) nanocomposites for bone tissue application

The main focus of this investigation is to explore novel minerals (M) substituted hydroxyapatite (M-HAP) as reinforcing agents to strengthen poly(sorbitol sebacate adipate) (PSSA), a biodegradable polymer for soft and hard tissue applications.