Chemical conjugates of paclitaxel and hyaluronic acid (HA) were synthesized by utilizing a novel HA solubilization method in a single organic phase. Hydrophilic HA was completely dissolved in anhydrous DMSO with addition of poly(ethylene glycol) (PEG) by forming nanocomplexes. Paclitaxel was then chemically conjugated to HA in the DMSO phase via an ester linkage without modifying extremely hydrophilic HA. A series of HA-paclitaxel conjugates with different conjugation percentages were synthesized and characterized. HA-paclitaxel conjugates self-assembled in aqueous solution to form nanosized micellar aggregates, as characterized by dynamic light scattering (DLS), atomic force microscopy (AFM), and transmission electron microscopy (TEM). An intact form of paclitaxel was regenerated from HA-paclitaxel conjugate micelles at acidic pH conditions. HA-paclitaxel conjugate micelles exhibited more pronounced cytotoxic effect for HA receptor overexpressing cancer cells than for HA receptor deficient cells, suggesting that they can be potentially utilized as tumor-specific nanoparticulate therapeutic agents.

No abstract

No abstract

Hydrogel‐based biosensors have drawn considerable attention due to their various advantages over conventional detection systems. Recent studies have shown that hydrogel biosensors can be excellent alternative systems to detect a wide range of biomolecules, including small biochemicals, pathogenic proteins, and disease specific genes. Due to the excellent physical properties of hydrogels such as the high water content and stimuli‐responsive behavior of cross‐linked network structures, this system can offer substantial improvement for the design of novel detection systems for various diagnostic applications. The other main advantage of hydrogels is the role of biomimetic three‐dimensional (3D) matrix immobilizing enzymes and aptamers within the detection systems, which enhances their stability. This provides ideal reaction conditions for enzymes and aptamers to interact with substrates within the aqueous environment of the hydrogel. In this review, we have highlighted various novel detection approaches utilizing the outstanding properties of the hydrogel. This review summarizes the recent progress of hydrogel‐based biosensors and discusses their future perspectives and clinical limitations to overcome.

Eine gezielte Genstummschaltung in Krebszellen gelang mit magnetischen Eisenoxid‐Nanopartikeln (MEIO), an denen ein Fluoreszenzfarbstoff, siRNA sowie ein RGD‐Peptid zur Erkennung von Krebszellen angebracht waren (siehe Bild). Die verschiedenen funktionellen Einheiten ermöglichen eine kombinierte makroskopische (Kernspin‐) und mikroskopische (Fluoreszenz‐)Tomographie der Zielzellen. Dieses System könnte sich für die parallele diagnostische und therapeutische Anwendung eignen.