Efficient delivery of recombinant human bone morphogenetic protein (rhBMP‑2) with dextran sulfate‑chitosan microspheres

Abstract

Bone morphogenetic protein-2 (BMP-2) serves an important role in the development of bone and cartilage. However, administration of BMP-2 protein alone by intravenous delivery is not very effective. Sustained delivery of stabilized BMP-2 by carriers has been proven necessary to improve the osteogenesis effect of BMP-2. The present study constructed a novel drug delivery system using dextran sulfate (DS)-chitosan (CS) microspheres and investigated the efficiency of the delivery system on recombinant human bone morphogenetic protein (rhBMP-2). The microsphere morphology, optimal ratio of DS/CS/rhBMP-2, and drug loading rate and entrapment efficiency of rhBMP-2 CS nanoparticles were determined. L929 cells were used to evaluate the cytotoxicity and effect of DS/CS/rhBMP-2 microspheres on cell proliferation. Differentiation study was conducted using bone marrow mesenchymal stem cells (BMSCs-C57) cells treated with DS/CS/rhBMP-2 microspheres or the control microspheres. The DS/CS/rhBMP-2 microspheres delivery system was successfully established. Subsequent complexation of rhBMP-2-bound DS with polycations afforded well defined microspheres with a diameter of ~250 nm. High protein entrapment efficiency (85.6%) and loading ratio (47.245) µg/mg were achieved. Release of rhBMP-2 from resultant microspheres persisted for over 20 days as determined by ELISA assay. The bioactivity of rhBMP-2 encapsulated in the CS/DS microsphere was observed to be well preserved as evidenced by the alkaline phosphatase activity assay and calcium nodule formation of BMSCs-C57 incubated with rhBMP-2-loaded microspheres. The results demonstrated that microspheres based on CS-DS polyion complexes were a highly efficient vehicle for delivery of rhBMP-2 protein. The present study may provide novel orientation for bone tissue engineering for repairing and regenerating bone defects.

Effect of recombinant human bone morphogenetic protein delivered by chitosan microspheres on ectopic osteogenesis in rats

“…The measurement of the in vitro sustained-release profile was in accordance with that of a previous study by our group and another study (17,18). In brief, 50 mg CS/rhBMP-2 microspheres were immersed in 2 ml PBS (pH 7.4), followed by agitation in a water bath oscillator.…”

“…The preparation of CS blank microspheres and CS/rhBMP-2 microspheres was performed using a procedure modified from a previous study (17), namely 42 ml thiamine pyrophosphate solution was added instead of DS and ZnSO 4 . In brief, to prepare CS blank microspheres, a certain amount of CS (molecular weight, 50,000-190,000; Aladdin Reagent Co. Ltd., Shanghai, China) was dissolved in 1% (v/v) acetic acid and the pH was adjusted to 5.4 by addition of NaOH solution to obtain a mixture with a CS concentration of 1.52 mg/ml.…”

Mesoporous Hydroxyapatite/Chitosan Loaded With Recombinant-Human Amelogenin Could Enhance Antibacterial Effect and Promote Periodontal Regeneration

“…The mHA, CS and mHA/CS suspension liquids were mixed with 20 µg/mL rhAm. The controlled release effect of mHA/CS was measured according to the approach described by Xia et al with some modifications (Xia et al, 2018). The mHA and mHA/CS composite particles were immersed in phosphate-buffered saline solution (PBS, Sigma, USA) for 24 h in the presence of 20 µg/mL rhAm.…”

Efficient in vivo bone formation by BMP-2 engineered human mesenchymal stem cells encapsulated in a projection stereolithographically fabricated hydrogel scaffold

“…Currently, there are two major ways to overcome this issue: (1) controlled release through physical binding/trapping of BMP-2 protein within the delivery vehicles [28] or (2) gene transfer-based genetic engineering of cells with the BMP-2 gene [29]. For example, rhBMP-2 was encapsulated in poly (lactic-co-glycolic acid) (PLGA) microparticles, with a sustained release profile of over 5 weeks, to bridge a rat critical cranial defect [30].…”