Osteogenic composite nanocoating based on nanohydroxyapatite, strontium ranelate and polycaprolactone for titanium implants

Titanium and its alloys are commonly used as dental and bone implant materials.Biomimetic coating of titanium surfaces could improve their osteoinductive properties.In this work,we have developed a novel osteogenic composite nanocoating for titanium surfaces,which provides a natural environment for facilitating adhesion,proliferation,and osteogenic differentiation of bone marrow mesenchymal stem cells(MSCs).Electrospinning was used to produce composite nanofiber coatings based on polycaprolactone(PCL),nano-hydroxyapatite(nHAp)and strontium ranelate(SrRan).Thus,four types of coatings,i.e.,PCL,PCL/nHAp,PCL/SrRan,and PCL/nHAp/SrRan,were applied on titanium surfaces.To assess chemical,morphological and biological properties of the developed coatings,EDS,FTIR,XRD,XRF,SEM,AFM,in-vitro cytotoxicity and in-vitro hemocompatibility analyses were performed.Our findings have revealed that the composite nanocoatings were both cytocompatible and hemocompatible;thus PCL/HAp/SrRan composite nanofiber coating led to the highest cell viability.Osteogenic culture of MSCs on the nanocoatings led to the osteogenic differentiation of stem cells,confirmed by alkaline phosphatase activity and mineralization measurements.The findings support the notion that the proposed composite nanocoatings have the potential to promote new bone formation and enhance bone-implant integration.

Comparison of Strontium Ranelate and Alendronate Sodium Treatment among Post-Menopausal Women

Growing rates of osteoporosis in the whole world is a serious health problem. As the “expected lifetime” is prolonged, population of elderly women with chronic diseases who require long-term treatment increases. This study aimed to compare antiresorptive treatment—that has become a classic treatment in the light of Canadian Guideline for osteoporosis—with the antiresorptive plus osteoblastic activity inducing treatment modality. The clinical and laboratory results of patients treated with a single dose of 2 mg Strontium ranelate sachet (Protelos &reg) or alendronate sodium used weekly 70 mg tablet (Fosamax &reg once a week tablet) for 12-months were compared. Treatment compliance has been questioned. A hundred women in post-menopausal period were included in this study. Patient satisfaction survey among the group of strontium ranelate was unsatisfactory. Among patients using alendronate sodium the ease of use in this sense obtained a rate of 91% satisfaction from patients.

Strontium ranelate incorporated 3D porous sulfonated PEEK simulating MC3T3-E1 cell differentiation

Polyetheretherketone(PEEK)has been used as an implant material because it has similar mechani-cal properties to natural bone.However,inferior osseointegration and bioinertness hamper the clinical application of PEEK.In this study,the surfaces of sulfonated three-dimensional(3D)PEEK porous structures were loaded with different concentrations of strontium ranelate,a compound commonly used in the treatment or prevention of osteoporosis by promoting bone formation and inhibiting bone resorption.Field-emission scanning electron microscopy was used to characterize the topography of the structures,elemental carbon,oxygen and strontium contents were mea-sured by X-ray photoelectron spectroscopy,and surface zeta potentials and water-contact angle were also measured.The results indicated that strontium ranelate was successfully loaded onto the 3D porous structures.In vitro cellular results showed that strontium ranelate-treated sulfonated PEEK(SP-SR)strengthened the adhesion of MC3T3-E1 cells.The activity of alkaline phosphatase,collagen secretion and extracellular matrix mineralization deposition of MC3T3-E1 cells were also improved on the surface of SP-SR.These results indicate that SP-SR could serve a new implant candidate for surgical treatment.

Chinese topical herbal medicine gives additive effect on pharmaceutical agent on fracture healing

OBJECTIVE:To investigate the efficacy on the combination of oral strontium ranelate(Sr R)with a topical Chinese herbal paste on facilitation of fracture healing.METHODS:An open fracture was created at the mid-shaft of the right tibia of rat.A herbal pastecalled CDR containing Honghua(Flos Carthami),Chuanxuduan(Radix Dipsaci Asperoidis)and Dahuang(Radix Et Rhizoma Rhei Palmati)was prepared.The rats were treated with either CDR topically on the fracture site,or Sr R orally,or their combinations.Bone turnover biochemical markers in serum were measured.Microarchitecture of the fracture was analyzed using micro-CT after 14 and 28 d,followed by histomorphometrical analysis.RESULTS:Micro-computed tomography analysis revealed that the combined treatment of CDR with600 mg/g Sr R significantly increased the total callus density,mineralized callus volume fraction,mineralized callus mineral content and mineralized callus density of the callus after 28 d of treatment.This result was consistent with the histomorphometrical analysis on the osteoid volume.Analysis of biochemical markers showed that the combined treatments reduced the bone resorption that occurs temporarily after fracture.CONCLUSION:This study demonstrated that the combined treatment of oral Sr R and topical CDR is effective to promote fracture healing by their additive effect on promoting bone formation and retarding bone resorption.