Local delivery of ceramide for restenosis: is there a future for lipid therapy?

Bonding behavior of hydrophobically modified gelatin films on the intestinal surface

The bonding behavior was determined for hydrophobically modified alkaline-treated gelatin on wet porcine intestinal surfaces. The modified gelatin films were obtained by reacting the amino groups of alkaline-treated gelatin with fatty acid chlorides of different alkyl chain lengths, namely, hexanoyl (Hx: C6) chloride, decanoyl (Dec: C10) chloride, and stearoyl (Ste: C18) chloride. Three kinds of the films were prepared, 32HxAlGltn, 24DecAlGltn, and 26SteAlGltn that had substitution ratios of hydrophobic groups to the amino groups of 32HxAlGltn, 24DecAlGltn, and 26SteAlGltn of 32%, 24%, and 26%, respectively. The 32HxAlGltn film had the strongest bonding to porcine intestinal surfaces. A thick 32HxAlGltn film remained on the intestinal surface even after the bonded film was scraped off for the measurement of bonding strength. In addition, the burst strength increased with an increase in the substitution ratio of the Hx group. Thus, the HxAlGltn film with the higher Hx modification ratio has a potential as a sealant material to prevent agglutination of intestinal surfaces.

Enhancement in anti-proliferative effects of paclitaxel in aortic smooth muscle cells upon co-administration with ceramide using biodegradable polymeric nanoparticles

PURPOSE

Using a combination of paclitaxel (PTX), and the apoptotic signaling molecule, C6-ceramide (CER), the enhancement in anti-proliferative effect of human aortic smooth muscle cells (SMC) was examined by administering in polymeric nanoparticles.

METHODS

PTX- and CER-loaded poly(ethylene oxide)-modified poly(epsilon caprolactone) (PEO-PCL) nanoparticles were formulated by solvent displacement and characterized. The uptake and intracellular localization of the nanoparticle in SMC was examined using Z-stack fluorescent confocal microscopy. Anti-proliferative and pro-apoptotic effects of SMC were determined upon administration of PTX and CER, either as single agent or in combination, in aqueous solution and in PEO-PCL nanoparticle formulations.

RESULTS

High encapsulation efficiencies (i.e., >95%) of PTX and CER at 10% (w/w) loading were attained in the PEO-PCL nanoparticles of around 270 nm in diameter. Fluorescence confocal analysis showed that nanoparticle delivery did facilitate cellular uptake and internalization. Additionally, combination of PTX and CER delivery in PEO-PCL nanoparticles was significantly more effective in decreasing the proliferation of SMC, probably by enhancing the apoptotic response.

CONCLUSIONS

The results of this study show that combination of PTX and CER when administered in PEO-PCL nanoparticles can significantly augment the anti-proliferative effect in SMC. This strategy may potentially be useful in the treatment of coronary restenosis.