Band 6, Heft 4

Combining liposomes with magnetic nanoparticles is an intriguing approach to create multifunctional vesicles for medical applications, which range from controlled drug delivery vehicles to diagnostic imaging enhancers. Over the past decade, significant effort has been invested in developing such hybrids – widely known as magnetoliposomes – and has led to numerous new concepts. This review provides an overview on of the current state of the art in this field. The concept of magnetic fluid hyperthermia and stimuli-responsive nanoparticles for drug delivery is briefly recapitulated. The materials needed for these hybrids are addressed as well. The three typically followed approaches to associate magnetic nanoparticles to the liposomes are described and discussed more in detail. The final chapters are dedicated to the analytical methods used to characterize these hybrids and to theoretical considerations relevant for bilayer-embedded nanoparticles.

Beta-casein (bCN) micelles were developed as a platform for improved oral bioavailability (BA) of poorly water-soluble drugs. Here we demonstrate a proof-of-concept using the NSAID celecoxib (Cx) loaded into bCN micelles (Cx/bCN). In a crossover pharmacokinetic (PK) study in pigs (n=4), dosed intraduodenally with either the commercial Cx formulation Celebra ® or Cx/bCN, the C max obtained after administration of Cx/bCN was 2.3-fold higher and the T max was 1.57-fold faster, leading to a 1.76-fold increase in the BA of Cx, compared to the Celebra ® formulation. It is suggested that this BA enhancement was caused by improvement of Cx solubility in intestinal fluids by bCN micelles, which maintained their Cx cargo in an amorphous state.

Albendazole (ABZ), a well-established antiparasitic drug, has been shown to suppress tumor growth in a number of preclinical models of cancer. However, the low solubility of ABZ limits its use as a systemic anticancer agent. To enable systemic administration, we have formulated ABZ into albumin nanoparticles with a size range of 200–300 nm, which were cross-linked with glutaraldehyde to stabilize the nanoparticles and to introduce pH-responsive features. Drug release studies demonstrated that about 20% of ABZ was released at neutral pH within a week in comparison to 70% at slightly acidic condition (pH 5). Cellular uptake studies using ovarian cancer cells indicated that nanoparticles were internalized efficiently within 1 h of incubation. Further, cell proliferation results demonstrated that albumin nanoparticles alone showed no cytotoxicity to both normal and cancer cells. In contrast, the drug-loaded nanoparticles exhibited cellular toxicity and high killing efficacy to cancer cells compared to normal cells. Collectively, our results suggest that these albumin nanoparticles may hold great potentials as ABZ carriers for cancer therapy.

Background: Prevention of surgical site infection and wound dehiscence are imperative and also challenging in clinical practice. This study examines the healing response of laparotomy wounds following application of silver nanoparticles. Materials and Methods: Dermal fibroblasts were exposed to incremential doses of silver nanoparticles and its effect on collagen synthesis and cytotoxicity was assessed. Laparotomy surgery was performed on rabbits and the operation site was treated topically either with silver nanoparticle once, or once daily for 14 days or with vehicle. Healing response and local tissue reaction was evaluated clinically by histopathology and scanning electron microscopy (SEM); microbial load on the operation site was assessed. Clinical tests and histopathology were performed to assess systemic toxicity. Results: Silver nanoparticles increased collagen expression from dermal fibroblasts and longer time exposure increased caspase 3 expression and produced cyotoxic effect with an IC50 of 0.16 mg/mL. Daily treatment of operation sites resulted in increased collagen deposition and improved wound healing, microbial load was reduced. Although a sub dermal edema was evident in histopathology, SEM showed normal architecture of cells with infiltration of lymphocytes. There was no systemic toxicity. Conclusions: Silver nanoparticles exhibit a positive influence on wound healing but its effect on local tissue remains a concern.