Controlled-release of rhBMP-2 carriers in the regeneration of osteonecrotic bone

Growth Factor-Loaded Microparticles for Tissue Engineering: The Discrepancies of In Vitro Characterization Assays

“…For instance, Wang et al showed that after GF lyophilization, they had lost 75% of the BMP-2 detectable by ELISA and thus increased their in vivo dose for compensation, stating that 75% of the bioactivity was lost. 43 This approach is erroneous considering that the ELISA is steadily proven here to be a misleading means of GF detection and that cell assays remain a superior method for assessing the effectiveness of processed GFs.…”

Osteonecrosis of the femoral head: treatment with ancillary growth factors

“…This would provide a scaffold allowing for ingrowth of bone and also blood vessels, while recruiting MSCs to the area to form bone [24]. Various scaffolds composed of PLGA, collagen hydroxyapatite, and β-TCP have been used to Bcarry^BMP-2 and release it over a sustained period of time [22,24,31,32,38,39].…”

“…Various scaffolds composed of PLGA, collagen hydroxyapatite, and β-TCP have been used to Bcarry^BMP-2 and release it over a sustained period of time [22,24,31,32,38,39]. In a study by Wang and colleagues, an improvement in healing of necrotic segments of bone with controlled release of BMP was noted [24]. The authors were able to determine that a continued release of BMP over a 1-week time period led to replacement of necrotic bone with new bone through creeping substitution and neovascularization of the necrotic segment [24].…”

Local delivery of controlled-release simvastatin/PLGA/HAp microspheres enhances bone repair

“…29 Briefly, 16 mg of HAp powder (Alfa Aesar ® , A Johnson Matthey Company, Ward Hill, MA, USA) was dissolved into phosphate-buffered saline to form the first water-phase solution. A 250 µL sample of 10 mM simvastatin stock solution and 5 mg of Span 80 (Showa, Chemicals, Inc., Japan) were mixed with 10% PLGA50/50 (P2191, molecular weight 30,000-60,000, Sigma-Aldrich) in a dichloromethane solution (Reagent ACS, Fluka, Buchs, Switzerland) to form the oil phase.…”

“…28 Based on this concept, our previous study demonstrated that a controlled-released PLGA/HAp carrier releases the optimal concentration of recombinant human BMP-2 and improves new bone formation in a bone repair animal model. 29 In this study, we fabricated a biodegradable carrier of PLGA/HAp to encapsulate simvastatin (SIM/PLGA/HAp) using a double emulsion method. We tested the osteogenic effects of SIM/ PLGA/HAp in mouse bone marrow mesenchymal stem cells and further tested its effects on bone repair using a mouse model of gap fracture bridging with a graft of necrotic bone, as in our earlier study.…”