Cerium Oxide Nanoparticle Incorporated Electrospun Poly(3-hydroxybutyrate-co-3-hydroxyvalerate) Membranes for Diabetic Wound Healing Applications.

Insufficient cell proliferation, cell migration, and angiogenesis are among the major causes for nonhealing of chronic diabetic wounds. Incorporation of cerium oxide nanoparticles (nCeO2) in wound dressings can be a promising approach to promote angiogenesis and healing of diabetic wounds. In this paper, we report the development of a novel nCeO2 containing electrospun poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) membrane for diabetic wound healing applications. In vitro cell adhesion studies, chicken embryo angiogenesis assay, and in vivo diabetic wound healing studies were performed to assess the cell proliferation, angiogenesis, and wound healing potential of the developed membranes. The experimental results showed that nCeO2 containing PHBV membranes can promote cell proliferation and cell adhesion when used as wound dressings. For less than 1% w/w of nCeO2 content, human mammary epithelial cells (HMEC) were adhered parallel to the individual fibers of PHBV. For higher than 1% w/w of nCeO2 content, cells started to flatten and spread over the fibers. In ovo angiogenic assay showed the ability of nCeO2 incorporated PHBV membranes to enhance blood vessel formation. In vivo wound healing study in diabetic rats confirmed the wound healing potential of nCeO2 incorporated PHBV membranes. The study suggests that nCeO2 incorporated PHBV membranes have strong potential to be used as wound dressings to enhance cell proliferation and vascularization and promote the healing of diabetic wounds.

1-Pyrene carboxylic acid functionalized carbon nanotube-gold nanoparticle nanocomposite for electrochemical sensing of dopamine and uric acid.

A highly sensitive, selective and cost effective method is described for sensing dopamine (DA) and uric acid (UA). A glassy carbon electrode (GCE) was modified with a nanocomposite consisting of gold nanoparticle-loaded multi-walled carbon nanotube (CNT) modified with 1-pyrene carboxylic acid (PCA). The stable aqueous dispersion of non-covalently functionalized CNT-PCA is an efficient bioprobe for the ultra sensitive and selective detection of dopamine and uric acid in the presence of the potentially interfering agent ascorbic acid (AA). The presence of PCA on the CNT introduces anionic carboxyl groups which repel ascorbate. The presence of the pyrene group augments high electrocatalytic activity towards oxidation of DA and UA, and the gold nanoparticles contribute to the amplification of the signal. The modified GCE gives an excellent peak current with well distinguishable peaks for AA, DA and UA (near -0.08 V, +0.14 V, and +0.22 V vs Ag/AgCl) in differential pulse voltammetry. Chronoamperometric detection of DA (working potential of 0.16 V vs Ag/AgCl) and UA (working potential of 0.3 V vs Ag/AgCl) showed linear ranges of 1 nM-150 µM (LOD 1 nM) and 1 µM-240 µM (LOD 1 µM) for DA and UA, respectively. The nanoprobe was validated by monitoring the recovery of spiked DA and UA in human blood serum samples which indicated a recovery within ±2%. Graphical abstract A glassy carbon electrode modified with a gold nanoparticle-loaded multi-walled carbon nanotube (CNT) - 1-pyrene carboxylic acid (PCA) composite was used for the sensitive and selective detection of the dopamine and uric acid.

Yttrium oxide nanoparticle loaded scaffolds with enhanced cell adhesion and vascularization for tissue engineering applications.

In situ tissue engineering is emerging as a novel approach in tissue engineering to repair damaged tissues by boosting the natural ability of the body to heal itself. This can be achieved by providing suitable signals and scaffolds that can augment cell migration, cell adhesion on the scaffolds and proliferation of endogenous cells that facilitate the repair. Lack of appropriate cell proliferation and angiogenesis are among the major issues associated with the limited success of in situ tissue engineering during in vivo studies. Exploitation of metal oxide nanoparticles such as yttrium oxide (Y2O3) nanoparticles may open new horizons in in situ tissue engineering by providing cues that facilitate cell proliferation and angiogenesis in the scaffolds. In this context, Y2O3 nanoparticles were synthesized and incorporated in polycaprolactone (PCL) scaffolds to enhance the cell proliferation and angiogenic properties. An optimum amount of Y2O3-containing scaffolds (1% w/w) promoted the proliferation of fibroblasts (L-929) and osteoblast-like cells (UMR-106). Results of chorioallantoic membrane (CAM) assay and the subcutaneous implantation studies in rats demonstrated the angiogenic potential of the scaffolds loaded with Y2O3 nanoparticles. Gene expression study demonstrated that the presence of Y2O3 in the scaffolds can upregulate the expression of cell proliferation and angiogenesis related biomolecules such as VEGF and EGFR. Obtained results demonstrated that Y2O3 nanoparticles can perform a vital role in tissue engineering scaffolds to promote cell proliferation and angiogenesis.

Nanosheets of nickel, cobalt and manganese triple hydroxides/oxyhydroxides as efficient electrode materials for asymmetrical supercapacitors.

Transition metals play a significant role in energy storage applications mainly as electrode materials in supercapacitors. In this work, triple hydroxide/oxyhydroxide nanosheets of a nickel, cobalt and manganese (NCM) composite were electrochemically deposited on carbon cloth (CC) and used as electrode materials in supercapacitors. In a three electrode system the composite delivered a specific capacitance of 707 F g-1 at a current density of 3 A g-1 which retained its stability even at a higher current density of 50 A g-1. An asymmetric supercapacitor (ASC) was assembled and characterized using NCM as the positive electrode, activated carbon as the negative electrode and Whatman filter paper soaked in KOH as the separator. The device operated in a working potential window of 1.75 V and it delivered a power density of 13.12 kW kg-1 and an energy density of 23.7 W h kg-1.

Nanoceria Can Act as the Cues for Angiogenesis in Tissue-Engineering Scaffolds: Toward Next-Generation in Situ Tissue Engineering.

Next-generation tissue engineering exploits the body's own regenerative capacity by providing an optimal niche via a scaffold for the migration and subsequent proliferation of endogenous cells to the site of injury, enhancing regeneration and healing and bypassing laborious in vitro cell-culturing procedures. Such systems are also required to have a sufficient angiogenic capacity for the subsequent patency of implanted scaffolds. The exploitation of redox properties of nanodimensional ceria (nCeO2) in in situ tissue engineering to promote cell adhesion and angiogenesis is poorly investigated. As a novel strategy, electrospun polycaprolactone based tissue-engineering scaffolds loaded with nCeO2 were developed and evaluated for morphological and physicomechanical features. In addition, in vitro and in vivo studies were performed to show the ability of nCeO2-containing scaffolds to enhance cell adhesion and angiogenesis. These studies confirmed that nCeO2-containing scaffolds supported cell adhesion and angiogenesis better than bare scaffolds. Gene-expression studies had shown that angiogenesis-related factors such as HIF1α and VEGF were up-regulated. Overall results show that incorporation of nCeO2 plays a key role in scaffolds for the enhancement of angiogenesis, cell adhesion, and cell proliferation and can produce a successful outcome in in situ tissue engineering.