Application of Nanotechnology in Targeting of Cancer Stem Cells: A Review

Cancer is increasingly apparent as a systems-level, network happening. The central tendency of malignant alteration can be described as a two-phase procedure, where an initial increase of network plasticity is followed by reducing plasticity at late stages of tumor improvement. Cancer stem cells (CSCs) are cancer cells that take characteristics associated with normal stem cells. Cancer therapy has been based on the concept that most of the cancer cells have a similar ability to separate metastasise and kill the host. In this review, we addressed the use of nanotechnology in the treatment of cancer stem cells.

Herbal extract loaded chitosan-based nanofibers as a potential wound-dressing

Semelil is an herbal-based compound which is used for the treatment of chronic wounds, especially diabetic foot ulcers. On the other hand, Electrospun nanofibers have many characteristics such as mimicking extracellular matrix structure, efficiency as bacterial barrier, appropriate water vapor transmission rate, and provision of adequate gaseous exchange which make them ideal candidates for wound-healing application. The aim of this study was to incorporate Semelil in electrospun nanofibers to benefit both the advantages of Semelil and electrospun nanofibers for the treatment of wounds. To this aim, the blend solution of chitosan, polyethylene oxide [PEO] and the herbal extract were electrospun and chitosan-based nanofibers loaded with the herbal extract were fabricated. The as-spun fibers were characterized by scanning electron microscopy [SEM], Fourier transform infrared spectroscopy [FTIR] and thermogravimetric analysis [TGA]. The swelling ratio and drug release behavior of the electrospun fibers were also studied. Uniform and bead-free nanofibrous mats loaded with 10-50 Wt. %extract were successfully fabricated. The FTIR spectrum indicated that the chemical nature of chitosan was not changed in the process of electrospinning. TGA analysis confirm both polymers and extract in electrospun mats. The extract loaded mats showed a high swelling ratio and a burst release of extract after 1h incubation in PBS. Mats with lower amount of drug exhibited graduate increase in the cumulative release of drug after initial burst release

Genipin cross-linked electrospun chitosan-based nanofibrous mat as tissue engineering scaffold

To improve water stability of electrospun chitosan/ Polyethylene oxide [PEO] nanofibers, genipin, a biocompatible and nontoxic agent, was used to crosslink chitosan based nanofibers. Different amounts of genipin were added to the chitosan/PEO solutions, chitosan/PEO weight ratio 90/10 in 80% acetic acid, and the solutions were then electrospun to form nanofibers. The spun nanofibers were exposed to water vapor to complete crosslinking. The nanofibrous membranes were subjected to detailed analysis by scanning electron microscopy [SEM], Fourier transform infrared-attenuated total reflection [FTIR-ATR] spectroscopy, swelling test, MTT cytotoxicity, and cell attachment. SEM images of electrospun mats showed that genipin-crosslinked nanofibers retained their fibrous structure after immerging in PBS [pH=7.4] for 24 hours, while the uncrosslinked samples lost their fibrous structure, indicating the water stability of genipincrosslinked nanofibers. The genipin-crosslinked mats also showed no significant change inswelling ratio in comparison with uncrosslinked ones. FTIR-ATR spectrum of uncrosslinked and genipin-crosslinked chitosan nanofibers revealed the reaction between genipin and amino groups of chitosan. Cytotoxicity of genipin-crosslinked nanofibers was examined by MTT assay on human fibroblast cells in the presence of nanofibers extraction media. The genipincrosslinked nanofibers did not show any toxic effects on fibroblast cells at the lowest and moderate amount of genipin. The fibroblast cells also showed a good adhesion on genipincrosslinked nanofibers. This electrospun matrix would be used for biomedical applications such as wound dressing and scaffold for tissue engineering without the concern of toxicity