Recently, we have developed a photopolymerizable poly(l-lysine) (PLL) that can be covalently incorporated into poly(ethylene glycol) diacrylate (PEGDA) hydrogels to improve their bioactivity by providing positive charges. To explore the potential of these PLL-grafted PEGDA hydrogels as a cell delivery vehicle and luminal filler in nerve guidance conduits for peripheral and central nerve regeneration, we varied the number of pendent PLL chains in the hydrogels by photo-cross-linking PEGDA with weight compositions of PLL (ϕPLL) of 0, 1, 2, 3, and 5%. We further investigated the effect of PLL grafting density on E14 mouse neural progenitor cell (NPC) behavior including cell viability, attachment, proliferation, differentiation, and gene expression. The amount of actually grafted PLL and charge densities were characterized, showing a proportional increase with the feed composition ϕPLL. NPC viability in 3D hydrogels was significantly improved in a PLL grafting density-dependent manner at days 7 and 14 postenc...
The successful applicability of gene therapy approaches will heavily rely on the development of efficient and safe nonviral gene delivery vectors, for example, cell-penetrating peptides (CPPs). CPPs can condense oligonucleotides and plasmid DNA (pDNA) into nanoparticles, thus allowing the t ... more
Dendrimers feature a defined number of terminal groups that may bind RNA or be functionalized with bioactive molecules. These competing uses of terminal groups may create an impasse if the requisite density of ligands depletes the number of terminal groups for binding sufficient RNA, or vic ... more
The development of clay bionanocomposites requires processing routes with nanostructural control. Moreover, moisture durability is a concern with water-soluble biopolymers. Here, oriented bionanocomposite coatings with strong in-plane orientation of clay platelets are for the first time pre ... more
Scientists are reporting discovery of a potential biochemical basis for the apparent cancer-fighting ability of broccoli and its veggie cousins. They found for the first time that certain substances in the vegetables appear to target and block a defective gene associated with cancer. Their ... more
Scientists in Japan are reporting development of a faster, less expensive version of the fabled polymerase chain reaction (PCR) a DNA test widely used in criminal investigations, disease diagnosis, biological research and other applications. The new method could lead to expanded use of PCR ... more
Researchers at Rice University in Texas have developed a new approach to fighting cancer, based on nanoscale particles that can both detect and destroy cancerous cells. The report appears in the American Chemical Society's journal Nano Letters. Current molecular imaging approaches only dete ... more