Uptake and intracellular fate of biocompatible nanocarriers in cycling and noncycling cells.

AIM: To elucidate whether different cytokinetic features (i.e., presence or absence of mitotic activity) may influence cell uptake and distribution of nanocarriers, in vitro tests on liposomes, mesoporous silica nanoparticles, poly(lactide-co-glycolide) nanoparticles and nanohydrogels were carried out on C2C12 murine muscle cells either able to proliferate as myoblasts (cycling cells) or terminally differentiate into myotubes (noncycling cells). MATERIALS & METHODS: Cell uptake and intracellular fate of liposomes, mesoporous silica nanoparticles, poly(lactide-co-glycolide) nanoparticles and nanohydrogels were investigated by confocal fluorescence microscopy and transmission electron microscopy. RESULTS: Nanocarrier internalization and distribution were similar in myoblasts and myotubes; however, myotubes demonstrated a lower uptake capability. CONCLUSION: All nanocarriers proved to be suitably biocompatible for both myoblasts and myotubes. The lower uptake capability of myotubes is probably due to different plasma membrane composition related to the differentiation process.

Evaluation of rheological properties and swelling behaviour of sonicated scleroglucan samples.

Scleroglucan is a natural polysaccharide that has been proposed for various applications. However there is no investigation on its property variations when the molecular weight of this polymer is reduced. Scleroglucan was sonicated at two different polymer concentrations for different periods of time and the effect of sonication was investigated with respect to molecular weight variations and rheological properties. Molar mass, estimated by viscometric measurements, was drastically reduced already after a sonication for a few min. Sonicated samples were used for the preparation of gels in the presence of borate ions. The effect of borax on the new samples was investigated by recording the mechanical spectra and the flow curves. A comparison with the system prepared with the dialysed polymer was also carried out. The anisotropic elongation, observed with tablets of scleroglucan and borax, was remarkably reduced when the sonicated samples were used for the preparation of the gels.

Recent advances and perspectives on coated alginate microspheres for modified drug delivery.

BACKGROUND: Alginate microspheres represent a useful tool for modified drug delivery. Their preparation is quite easy and is usually based on the gelling properties of the polysaccharide in the presence of divalent ions; nevertheless, microparticles prepared only with calcium alginate show several problems, mainly related to the mechanical stability and to the release that, in most cases, is too fast. To overcome such inconveniences, polymer-coated alginate microspheres and/or appropriately interpenetrating polymer network (semi-IPNs and IPNs) structures formed with alginate and other macromolecules were developed. OBJECTIVE: This article reports a synthetic overview on the most recent searches carried out on coated alginate microspheres. METHODS: After a section focused on the microsphere preparation, this article is divided into several main topics related to the specific polymer that was used as a coating material to provide a rationale in reporting literature data. In the last section, the advantages and disadvantages of the various approaches are discussed and the authors' opinion on perspectives for further studies and novel applications of coated alginate microspheres are reported. CONCLUSION: Ca(2+)-alginate microparticles could experience a new era if scientists will increase their efforts in developing microparticles with smart properties.

Hyaluronan as carrier of carboranes for tumor targeting in boron neutron capture therapy.

Boron neutron capture therapy (BNCT) represents a promising approach for tumor therapy. A critical requirement for BNCT is tumor targeting, a goal that is currently addressed with the development of low and high molecular weight agents capable of interacting with receptors expressed by cancer cells. Here, we describe a new bioconjugate (HApCB) composed by n-propyl carborane linked to hyaluronan (HA) via an ester linkage for a degree of substitution of approximately 30%, leading to a water-soluble derivative. The structure and main physicochemical characteristics of the new HA derivative were determined by means of Fourier transform infrared, fluorescence, and 1H, 13C, and 10B NMR analysis and are herein reported in detail. As HA is recognized by the CD44 antigen, densely populating the surface of many tumor cells, HApCB is expected to deliver boron atoms from the locally released carborane cages directly to target cells for antitumor application in BNCT. In vitro biological experiments showed that HApCB was not toxic for a variety of human tumor cells of different histotypes, specifically interacted with CD44 as the native unconjugated HA, and underwent uptake by tumor cells, leading to accumulation of amounts of boron atoms largely exceeding those required for a successful BNCT approach. Thus, HApCB may be regarded as a promising new BNCT agent for specific targeting of cancer cells overexpressing the CD44 receptor.