Preparation and physical characterization of calcium sulfate cement/silica-based mesoporous material composites for controlled release of BMP-2

Abstract

As a commonly used implant material, calcium sulfate cement (CSC), has some shortcomings, including low compressive strength, weak osteoinduction capability, and rapid degradation. In this study, silica-based mesoporous materials such as SBA-15 were synthesized and combined with CSC to prepare CSC/SBA-15 composites. The properties of SBA-15 were characterized by X-ray diffraction, transmission electron microscopy, and nitrogen adsorption–desorption isotherms. SBA-15 was blended into CSC at 0, 5, 10, and 20 wt%, referred to as CSC, CSC-5S (5% mass ratio), CSC-10S (10% mass ratio), and CSC-20S (20% mass ratio), respectively. Fourier-transform infrared spectroscopy and compression tests were used to determine the structure and mechanical properties of the composites, respectively. The formation of hydroxyapatite on composite surfaces was analyzed using scanning electron microscopy and X-ray diffraction after soaking in simulated body fluid. BMP-2 was loaded into the composites by vacuum freeze-drying, and its release characteristics were detected by Bradford protein assay. The in vitro degradation of the CSC/SBA-15 composite was investigated by measuring weight loss. The results showed that the orderly, nanostructured, mesoporous SBA-15 possessed regular pore size and structure. The compressive strength of CSC/SBA-15 increased with the increase in SBA-15 mass ratio, and CSC-20S demonstrated the maximum strength. Compared to CSC, hydroxyapatite that formed on the surfaces of CSC/SBA-15 was uniform and compact. The degradation rate of CSC/SBA-15 decreased with increasing mass ratio of SBA-15. The adsorption of BMP-2 increased and released at a relatively slow rate; the release rate of BMP-2 in CSC-20S was the slowest, and presented characteristics of low doses of release. In vitro experiments demonstrated that the physical properties of pure CSC incorporated with SBA-15 could be improved significantly, which made the CSC/SBA-15 composite more suitable for bone repair and bone-tissue engineering.

Pigment epithelium derived factor (PEDF) prevents methyl methacrylate monomer-induced cytotoxicity in H9c2 cells

“…Since bone cement was first used in clinics in 1970s, cardiac arrest cases have been reported following the use of MMA [ 17 ] . Although new types of bone cement such as calcium phosphate cement or calcium sulfate cement were invented, their low fracture toughness and poor mechanical reliability restrict their applica-tion [ 18–19 ] . Acrylic bone cement is still irreplaceable in clinics now.…”

Combination of simvastatin, calcium silicate/gypsum, and gelatin and bone regeneration in rabbit calvarial defects

“…It has also been reported that the combination of simvastatin and gypsum can stimulate bone regeneration 19 . It has been demonstrated that gypsum has potential as a carrier for local release of antibiotics, growth factors, and drugs 20 21 22 .…”