Biological evaluation and osteogenic potential of polyhydroxybutyrate-keratin/Al2O3 electrospun nanocomposite scaffold: A novel bone regeneration construct.

In this study, the effect of alumina nanowire on the physical and biological properties of polyhydroxybutyrate-keratin (PHB-K) electrospun scaffold was investigated. First, PHB-K/alumina nanowire nanocomposite scaffolds were made with an optimal concentration of 3 wt% alumina nanowire by using the electrospinning method. The samples were examined in terms of morphology, porosity, tensile strength, contact angle, biodegradability, bioactivity, cell viability, ALP activity, mineralization ability, and gene expression. The nanocomposite scaffold provided a porosity of >80 % and a tensile strength of about 6.72 MPa, which were noticeable for an electrospun scaffold. AFM images showed an increase in surface roughness with the presence of alumina nanowires. This led to an improvement in the degradation rate and bioactivity of PHB-K/alumina nanowire scaffolds. The viability of mesenchymal cells, alkaline phosphatase secretion, and mineralization significantly increased with the presence of alumina nanowire compared to PHB and PHB-K scaffolds. In addition, the expression level of collagen I, osteocalcin, and RUNX2 genes in nanocomposite scaffolds increased significantly compared to other groups. In general, this nanocomposite scaffold could be a novel and interesting construct for osteogenic induction in bone tissue engineering.

Switch off inflammation in spleen cells with CD40-targeted PLGA nanoparticles containing dimethyl fumarate.

The purpose of this study was designing and synthesizing a PLGA formulation targeted with anti-CD40 monoclonal antibody, which has suitable physicochemical properties as a dimethyl fumarate (DMF) drug delivery system having minimal cytotoxicity. Therefore, this research was performed to determine the effect of anti-CD40mAb-DMF-NPs on the expression of IL-1ß, IL-6 and TNF-α cytokine genes in mouse splenocytes. The toxicity of different groups, namely free PLGA, free DMF, DMF-containing PLGA, anti-CD40mAb-DMF-NPs, was evaluated by MTT assay. PLGA formulations conjugated with mAbCD40 were loaded with DMF drug that showed little cytotoxic effect against mouse splenocytes. QRT-PCR method was subsequently used to assess the effect of the mentioned groups on the expression of IL-1ß, TNF-α and IL-6 genes. After treatment of the cells with DMF alone or with polymer carriers, the expression of IL-1ß, IL-6 and TNF-α cytokine genes was significantly reduced. The decrease in expression was markedly higher in the antibody-targeted nanoparticles group relative to other treatment groups. Our results in this area are promising and provide a good basis for further future studies in this regard.