Mimicking Hierarchical Complexity of the Osteochondral Interface Using Electrospun Silk-Bioactive Glass Composites

The anatomical complexity and slow regeneration capacity of hyaline cartilage at the osteochondral interface pose a great challenge in the repair of osteochondral defects (OCD). In this study, we utilized the processing feasibility offered by the sol derived 70S bioactive glass and silk fibroin (mulberry Bombyx mori and endemic Indian non-mulberry Antheraea assama), in fabricating a well-integrated, biomimetic scaffolding matrix with a coherent interface. Differences in surface properties such as wettability and amorphousness between the two silk groups resulted in profound variations in cell attachment and extracellular matrix protein deposition. Mechanical assessment showed that the biphasic composites exhibited both an elastic region pertinent for cartilage tissue and a stiff compression resistant region simulating the bone phase. In vitro biological studies revealed that the biphasic mats presented spatial confinement for the growth and maturation of both osteoblasts and chondrocytes, marked by increased alkaline phosphatase (ALP) activity, osteopontin (OPN), sulfated glycosaminoglycan (sGAG) and collagen secretion in the cocultured mats. The non-mulberry silk based biphasic composite mats performed better than their mulberry counterpart, as evidenced by enhanced expression levels of key cartilage and bone specific marker genes. Therefore, the developed biphasic scaffold show great promise for improving the current clinical strategies for osteochondral tissue repair

Materials design towards sport textiles with low-friction and moisture-wicking dual functions

This paper was accepted for publication in the journal Materials and Design and the definitive published version is available at http://dx.doi.org/10.1016/j.matdes.2015.08.107In the field of sportswear, the structure and morphology of textiles are of great importance to achieve good moisture transport and low friction, which are two critical comfort-related properties. To improve these properties, dual-layer nanofibrous nonwoven mats were studied in this work. Core–shell nanofibers with a polyacrylonitrile (PAN)-rich core and a poly(vinylidene fluoride) (PVDF)-rich shell were fabricated by single-spinneret electrospinning and used as the inner layer of the dual-layer mats, while thick base-treated Cellulose Acetate (CA) nanofibrous mats were used as the outer layer. The core-located PAN and a small amount of PAN on the PAN/PVDF nanofiber surface ensure good moisture transport through the nanofibrous mats. The synergistic combination of a considerably hydrophobic PAN/PVDF inner layer and a highly hydrophilic CA outer layer induces a strong push–pull effect, resulting in efficient moisture transport from the inner to the outer layer. Furthermore, the fluorine-rich PVDF shell of the inner layer touches the human skin and provides a lubricating effect to enhance comfortability. This design provides a promising route for sports textiles with both good moisture-wicking and low friction

A Sweet Killer: Mesoporous Polysaccharide Confined Silver Nanoparticles for Antibacterial Applications

Silver nanoparticles (AgNP) confined within porous starch have been prepared in a simple, green and efficient manner, utilising the nanoporous structure of predominantly mesoporous starch (MS) to act as nanoparticle stabiliser, support and reducing surface. MS/AgNP materials present high surface areas (SBET > 150 m2 g−1) and mesopore volumes (Vmeso > 0.45 cm3 g−1). The interaction of the AgNP precursor and forming nanoparticle nuclei with the mesoporous domains of the porous polysaccharide, direct porosity to increasingly narrower and more defined pore size distributions, indicative of a degree of cooperative assembly. Transmission electron microscopy images indicated the presence of spherical AgNP of a size reflective of the porous polysaccharide mesopore diameter (e.g., 5–25 nm), whilst XPS analysis confirmed the metallic Ag0 state. Materials were prepared at relatively low Ag loadings (<0.18 mmol g−1), demonstrating excellent antimicrobial activity in solid and liquid phase testing against Gram negative (E. coli) and positive (S. aureus) model bacteria. The resulting materials are biocompatible and present a useful solid porous carbohydrate-based polymer vehicle to control the AgNP size regime and facilitate transference to a biological environment

Harnessing alginate-based nanocomposites as nucleic acid/gene delivery platforms to address diverse biomedical issues: A progressive review

Among various polysaccharides, alginate-based nanostructures have etched an indelible mark on the canvas of biomolecules’ delivery. Although several review articles on the use of alginates for the delivery of drugs and other bio-active agents can be retrieved from various literature repositories, however, the progress in the realm of alginate-based nanomaterials and its nanocomposites for nucleic acid/gene delivery has not been specifically reviewed of late. In this context, the write up in this article is geared off with highlights on alginate's structure-bioactivity concert, molecular modulations, and brief description about the different approaches to fabricate its various nanostructures. The subsequent section is then specifically streamlined towards comprehending the formulation, the biophysicochemical features and applications of alginate-based nanomaterials and nanocomposites for nucleic acid/ gene delivery applications to address various biomedical issues, as attested by a couple of topical investigations. Representative studies on gene delivery using alginate-based nanobiomaterials in research pertaining to cancer therapy, macrophage targeting and repolarization, intestine-inflammation targeting, bone regeneration, autosomal dominant polycystic kidney disease therapy and wound healing therapy, amongst others are presented. Various practical snags and prospective future direction of research in the use of alginate based nanobiomaterials for gene therapy are highlighted in the concluding section

Potential Nanomedicine Applications of Multifunctional Carbon Nanoparticles Developed Using Green Technology

Carbon nanonmaterial development through green technology is gaining pace owing to their biocompatibility, inertness, modifiability, and photoluminescence. These smart nanomaterials are much sought after and have great potential in bioimaging and drug delivery. In this study, we focused on the preparation of carbon nanoparticles (CNPs) using edible yogurt drink (lassi) by microwave irradiation. The physicochemical properties of synthesized CNPs were extensively studied. Results demonstrated that CNPs had average size of 12.58 ± 0.60 nm with a zeta potential of −24.62 ± 0.15 mV. The cytocompatibility of CNPs assessed using L929 and rat primary vascular smooth muscle cells (VSMCs) demonstrated enhanced viability after 48 h of incubation. At lower concentrations of CNP, intracellular calcium levels remain unaffected in VSMCs. Doxorubicin (Dox) was used as model molecule to evaluate sythesized CNPs for their efficacy in drug delivery. Dox-loaded CNPs (Dox-CNPs) showed pH-dependent (pH 4.6 and 7.4) drug release. Toxicity of Dox-CNPs assessed with MCF-7 and SAS cell lines indicated IC₅₀ values at 0.25 μg/mL. Cell cycle arrest, elevation of reactive oxygen species, and loss of inner mitochondrial membrane potential corroborated efficient delivery of Dox to the nuclei with enhanced activity. The successful delivery of drug into the nuclei and its subsequent pH-dependent release project CNPs as promising drug delivery vehicles for nanomedicine