The potential of combining bioactive glass(MBG) and silk fibroin(SF) together as a new drug delivery system was evaluated. The three-dimensional porous scaffolds were selected as the form of SF, and sol-gel method was adopted to fabricate MBG in this study. The characteristic of the synthesized material was measured by transmission electron microscopy and scanning electron microscopy. In vitro evaluation of drug delivery was carried out in terms of drug loading and drug release. And aspirin was chosen as the drug for scaffolds to carry out in vitro tests and repair BALB/C mice calvarial defects. Bone formation was examined by microcomputed tomography. The experimental results show that MBG/silk scaffolds have better physiochemical properties compared with silk scaffolds. In comparison to pure silk scaffolds, MBG/silk scaffolds enhance the drug loading efficiency, release rate in vitro and promote bone regeneration in vivo. Thus we conclude that MBG/silk scaffold is a more efficient drug delivery system than pure silk scaffolds.
Recent studies have shown that Er-Zhi-Wan(EZW),a traditional Chinese medicine consisting of Herba Ecliptae(HE)and Fructus Ligustri Lucidi(FLL),had a definite antiosteoporotic effect on osteoporotic femur,but its effect on osteoporosis of alveolar bone remains unknown.In the present study,we investigated the effects of Er-Zhi-Wan(EZW)on the microarchitecture and the regulation of Wnt/β-catenin signaling pathway in the alveolar bone of ovariectomized rats.Thirty Sprague-Dawley rats were randomly divided into three groups:sham operation group(sham,n=10),ovariectomy(OVX)group(n=10),and OVX with EZW treatment group(EZW group,n=10).From one week after ovariectomy,EZW(100 mg/mL)or vehicle(distilled water)was fed(1 mL/100 g)once per day for 12 weeks until the sacrifice of the rats.The body weights were measured weekly.After sacrifice,the sera and mandible were collected and routinely prepared for the measurement of alveolar trabecular microarchitecture,serum levels of E2,bone-specific alkaline phosphatase(BALP)and tartrate-resistant acid phosphatase 5b(TRAP5b),as well as mandibular mRNA expression of Wnt/β-catenin signaling pathway molecules wnt3a,low-density lipoprotein receptor-related protein 5(LRP5),β-catenin and dickkopf homolog 1(DKK1).The results showed that EZW treatment significantly prevented the body weight gain,degradation of alveolar trabecular microarchitecture and alveolar bone loss in the OVX rats.Furthermore,we observed that EZW could increase the serum levels of E2 and BALP,and decrease levels of serum TRAP5b in EZW group compared with vehicle group.In addition,RT-PCR results revealed that EZW upregulated the expression levels of wnt3a,LRP5 andβ-catenin,and reduced the expression of DKK1 in OVX rats.Taken together,our results suggested that EZW may have potential anti-osteoporotic effects on osteoporotic alveolar bone by stimulating Wnt/LRP5/β-catenin signaling pathway.
