The controlled release, bioactivity and osteogenic gene expression of Quercetin-loaded gelatin/tragacanth/ nano-hydroxyapatite bone tissue engineering scaffold.

In this study, a Gelatin/Tragacanth/Nano-hydroxyapatite scaffold was fabricated via freeze-drying method. A highly porous scaffold with an average pore diameter of 142 µm and porosity of 86% was found by the micro-computed tomography. The mean compressive strength of the scaffold was about 1.5 MPa, a value in the range of the spongy bone. The scaffold lost 10 wt.% of its initial weight after 28 days soaking in PBS that shows a fair degradation rate for a bone tissue engineering scaffold. Apatite formation ability of the scaffold was confirmed via scanning electron microscopy, X-ray diffraction and Fourier transforming infrared spectroscopy, after 28 days soaking in simulated body fluid. The scaffold was able to deliver 93% of the loaded drug, Quercetin, during 120 h in phosphate-buffered solution, in a sustainable manner. The MTT assay using human bone mesenchymal stem cells showed 84% cell viability of the Quercetin-loaded scaffold. The expression of the osteogenic genes including Col I, Runx-2, BGLAP (gene of osteocalcin), bFGF, SP7 (gene of osterix) and SPP1 (gene of osteopontin) were all upregulated when Quercetin was loaded on the scaffold, which indicates the synergetic effect of the drug and the scaffold.

In vitro evaluation of curcumin-loaded chitosan-coated hydroxyapatite nanocarriers as a potential system for effective treatment of cancer.

Nanotechnology has many potential applications in cancer treatment. For example, nano-drug delivery systems (NDDS) with high bioavailability, biodegradability, and biocompatibility have been developed, in order to increase the therapeutic effects of anticancer drugs. Among these NDDS, high-performance hydroxyapatite (HA) nanoparticles are rapidly advancing in the targeted cancer treatment due to their numerous benefits. Curcumin is an herbal metabolite that acts as a chemical inhibitor through the inhibition of tumor cells and the progression of many cancers. However, the poor bioavailability of curcumin is the most important challenge in using this substance. In this study, HA nanoparticles coated by chitosan were used as a pH-sensitive biopolymer to improve the efficiency and bioavailability of curcumin. For this purpose, HA nanoparticles were first synthesized by the sol-gel method. Then, a layer of chitosan was coated on it, and the curcumin drug was encapsulated in the nanocarrier, under controlled conditions. Techniques such as scanning electron microscopy (SEM), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FTIR) were used to characterize the nanocarriers. In the second part, nano-drugs prepared by various bioassays were examined. For this purpose, the rate of cytotoxicity by the methyl-thiazol-tetrazolium (MTT) assay and the rate of apoptosis induction by the acridine orange and ethidium bromide (AO/EB) staining method on the brain carcinoma U87MG cell line were investigated.

Delivery of curcumin by a pH-responsive chitosan mesoporous silica nanoparticles for cancer treatment.

Mesoporous silica nanocarriers as accommodate drug molecule capsules were synthesized and capped by chitosan natural polymer. This nanocarrier acts as a pH-responsive shield to increase the solubility and improvement of anticancer properties of curcumin against U87MG glioblastoma cancer cell line. The encapsulation efficiency and drug-loading content were measured 88.1 ± 4.76% and 8.81 ± 0.47%, respectively. The curcumin release from the CS-MCM-41 was slow and sustained at low pH (42.72 ± 2.29%) compared to the environment pH (19.54 ± 1.36%) in 96 h. The MTT evaluations showed that IC50 after 72 h treatment with free curcumin and curcumin-loaded CS-MCM-41 were 15.20 and 5.21 µg/mL (p <0.05). respectively.