In vivo evaluation of anticancer efficacy of drug loaded cockle shell-derived aragonite nanoparticles.

Doxorubicin (DOX) is an effective and commonly used anthracycline anticancer drug for the treatment of osteosarcoma (OS). However, its antitumor effect is hampered by the nonspecific distribution and significant adverse effects. Nanoparticles based drug delivery systems are promising approaches to maximize the anticancer efficacy while decrease the side effects. In this study, biogenic aragonite nanoparticles (ANPs) were developed from cockle shells and loaded with DOX. An orthotopic rat OS model was induced by UMR-106 cells tibia cavity injection. The anticancer efficacy study included five groups: normal control group, OS model group, free DOX group (2 mg/kg), DOX-ANPs 1 group (2 mg of equivalent DOX/kg) and DOX-ANPs 2 group (1.5 mg of equivalent DOX/kg). This study demonstrates that the DOX-ANPs treatment groups can significantly reduce the tumor volume and increase the surviving ratio as compared to the OS model group. In addition, these two DOX-ANPs groups showed less toxicity to the normal organs compared to the free DOX group. Furthermore, DOX-ANPs 2 group showed the similar anticancer efficacy as DOX-ANPs 1 group, which suggested that DOX loaded onto the ANPs may allow the reduction of chemotherapy doses. These results highlight the promising application of ANPs derived from cockle shells as an effective drug delivery system for a successful chemotherapy against OS. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 107B: 1898-1907, 2019.

Synthesis, characterization, and cytocompatibility of potential cockle shell aragonite nanocrystals for osteoporosis therapy and hormonal delivery.

Calcium carbonate is a porous inorganic nanomaterial with huge potential in biomedical applications and controlled drug delivery. This study aimed at evaluating the physicochemical properties and in vitro efficacy and safety of cockle shell aragonite calcium carbonate nanocrystals (ANC) as a potential therapeutic and hormonal delivery vehicle for osteoporosis management. Free and human recombinant parathyroid hormone 1-34 (PTH 1-34)-loaded cockle shell aragonite calcium carbonate nanocrystals (PTH-ANC) were synthesized and evaluated using standard procedures. Transmission electron microscopy and field emission scanning electron microscopy results demonstrated highly homogenized spherical-shaped aragonite nanocrystals of 30±5 nm diameter. PTH-ANC had a zeta potential of -27.6±8.9 mV. The encapsulation efficiency of the formulation was found to be directly proportional to the concentrations of the drug fed. The X-ray diffraction patterns revealed strong crystallizations with no positional change of peaks before and after PTH-ANC synthesis. Fourier transform infrared spectroscopy demonstrated no detectable interactions between micron-sized aragonite and surfactant at molecular level. PTH-ANC formulation was stabilized at pH 7.5, enabling sustained slow release of PTH 1-34 for 168 h (1 week). A 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide cytocompatibility assay in Human Foetal Osteoblast Cell Line hFOB 1.19 showed that ANC can safely support osteoblast proliferation up to 48 h whereas PTH-ANC can safely support the proliferation at 72 h and beyond due to the sustained slow release of PTH 1-34. It was concluded that due to its biogenic nature, ANC is a cytocompatible antiosteoporotic agent. It doubles as a nanocarrier for the enhancement of efficacy and safety of the bone anabolic PTH 1-34. ANC is expected to reduce the cost, dosage, and dose frequency associated with the use of PTH 1-34 management of primary and secondary forms of osteoporosis.

Effects of Sericin Pretreatment on the Expression of ECM Associated Protein in the Kidney of Diabetic Nephropathy Rats / 中国医科大学学报

Objective To investigate the effects of sericin pretreatment on the expression of extracellular matrix(ECM) associated protein in diabetic nephropathy(DN) rats' kidney.Methods Sixty six male SD rats were randomly divided into 3 groups(n=12):normal control group,DN model group and sericine pretreatment group.DN rats model in model group and sericine pretreatment group were established by intraperitoneally injection of streptozotocin(STZ).Blood glucose≥16.7 mmol/L was taken as the standard of successful modelization.The rats in sericine pretreatment group were lavaged with sericine(2.4 g·kg~(-1)·d~(-1)) for 35 days before injecting STZ.The enzymic method was used to measure the blood glucose.Type Ⅳ collagen(cⅣ)and laminin(LN)content in the serum were detected by ELBA.The expression of transforming growth factor-β_1,(TGF-β_1)and tissue inhibitors of maprix metalloproteinase-1(TMP-1) protein in the kidney was observed by immunohistochemical staining.The expression of Smad 3 protein in the kidney was detected by Western blot.Results Compared with normal control rats,the blood glucose,cⅣ and LN content in the serum,TGF-β_1,TIMP-1 and Smad 3 expression in the kidney of the model group rats increased obviously(P<0.01).The blood glucose,cⅣ and LN content in the serum,TGF-β_1,TMP-1 and Smad3 expression in the kidney of rats in sericine pretreatment group were significantly lower than those of the rats in model group(P<0.01).Conclusion Sericin pretreatment can inhibit the activation of TGF-β/Smad 3 signal pathway in the kidney of DN rats,and prevent the decrease of MMPs activity induced by up-regulation of TIMP-1.So sericin can prevent accumulation of ECM and glomerulosclerosis during DN,and has satisfactory apotropaic effects on the development of DN.