Benidipine-loaded nanoflower-likemagnesium silicate improves bone regeneration

Regeneration and reconstruction of bone tissue is always a challenge for clinicians due to the uncertainty of bone repair materials in terms of long-term and efficient effects on osteoblasts.Here,we propose a novel strategy combining benidipine,an antihypertensive drug and nanoparticles to synergistically promote the healing of bone defects.Loose and porous benidipine-loaded magnesium silicate nanoparticles were prepared and validated for their biosafety.The nanoparticles were efficiently taken up by preosteoblasts and uniformly distributed around the nucleus.After internalization into cells,the nanosystem is degraded by lysosomes,and the effect of promoting osteogenic differentiation is reflected by the continuous release of benidipine,silicon and magnesium ions.Our results clearly evaluated that the nanoflower-like magnesium silicate delivering benidipine tends to be more appropriate for the bone regeneration in preosteoblasts,indicating that it might be a potential approach in guiding bone repair in clinical applications.

Identification, synthesis and characterization of process related impurities of benidipine hydrochloride, stress-testing/stability studies and HPLC/UPLC method validations

Benidipine hydrochloride, used as an antihypertensive agent and long-acting calcium antagonist, is synthesized for commercial use as a drug substance in highly pure form. During the synthetic process development studies of benidipine, process related impurities were detected. These impurities were identified, synthesized and characterized and mechanisms of their formation were discussed in detail. After all standardization procedures, they were used as reference standards for analytical studies. In addition, a separate HPLC method was developed and validated for detection of residual 1-benzylpi- peridin-3-ol （Ben-2）, which is used during benidipine synthesis and controlled as a potential process related impurity. As complementary of this work, stress-testing studies of benidipine were carried out under specified conditions and a stability-indicating UPLC assay method was developed, validated and used during stability studies of benidipine.

Osteogenic effects of antihypertensive drug benidipine on mouse MC3T3-E1 cells in vitro

Hypertension is a prevalent systemic disease in the elderly,who can suffer from several pathological skeletal conditions simultaneously,including osteoporosis.Benidipine(BD),which is widely used to treat hypertension,has been proved to have a beneficial effect on bone metabolism.In order to confirm the osteogenic effects of BD,we investigated its osteogenic function using mouse MC3T3-E1 preosteoblast cells in vitro.The proliferative ability of MC3T3-E1 cells was significantly associated with the concentration of BD,as measured by methylthiazolyldiphenyl-tetrazolium bromide(MTT)assay and cell cycle assay.With BD treatment,the osteogenic differentiation and maturation of MC3T3-E1 cells were increased,as established by the alkaline phosphatase(ALP)activity test,matrix mineralized nodules formation,osteogenic genetic test,and protein expression analyses.Moreover,our data showed that the BMP2/Smad pathway could be the partial mechanism for the promotion of osteogenesis by BD,while BD might suppress the possible function of osteoclasts through the OPG/RANKL/RANK(receptor activator of nuclear factor-κB(NF-κB))pathway.The hypothesis that BD bears a considerable potential in further research on its dual therapeutic effect on hypertensive patients with poor skeletal conditions was proved within the limitations of the present study.