Fusogenic liposome delivers encapsulated nanoparticles for cytosolic controlled gene release

Cytoskeletal-antigen specific immunoliposome-targeted in vivo preservation of myocardial viability

Preservation of cell viability using Cytoskeletal-antigen Specific ImmunoLiposomes (antimyosin-CSIL) has been demonstrated in cell cultures. The current study utilized the same CSIL intervention for myocardial protection in an in vivo rabbit model of acute myocardial infarction. Rabbit hearts with experimental left ventricular myocardial infarction were treated with CSIL; control liposomes, [(CL), IgG-liposomes (IgG-L) or plain liposomes (PL)], or vehicle (placebo). Mean myocardial infarct size in rabbit hearts treated in vivo with CSIL was 5 times smaller than in those treated with non-specific CL or vehicle. Treatment of ischemic adult myocardium with CSIL results in significant preservation of myocardial viability by dramatically decreasing the infarct size relative to CL or placebo treatment. Immunohistochemical myocardial preservation of CSIL-treated hearts was confirmed by the lack of contraction band necrosis using histological H&E stains relative to controls. Electrocardiographic confirmation of reduction in myocardial injury after CSIL therapy relative to controls was also observed. Application of CSIL technology to non-cardiac tissues would confirm a broader applicability of this cell membrane lesion sealing technology.

[Uniqueness of the mucosal immune system for the development of prospective mucosal vaccine]

The mucosal immune system acts as the first line of defense against microbial infection through a dynamic immune network based on innate and acquired mucosal immunity. To prevent infectious diseases, it is pivotal to develop effective mucosal vaccines that can induce both mucosal and systemic immune responses, especially secretory IgA (S-IgA) and plasma IgG, against pathogens. Recent advances in medical and biomolecular engineering technology and progress in cellular and molecular immunology and infectious diseases have made it possible to develop versatile mucosal vaccine systems. In particular, mucosal vaccines have become more attractive due to recent development and adaptation of new types of drug delivery systems not only for the protection of antigens from the harsh conditions of the mucosal environment but also for effective antigen delivery to mucosa-associated lymphoid tissues such as Peyer's patches and nasopharynx-associated lymphoid tissue, the initiation site for the induction of the antigen-specific immune response. In this review, we shed light on the dynamics of the mucosal immune system and recent advances toward the development of prospective mucosal antigen delivery systems for vaccines.

Chemically modified short interfering hybrids (siHYBRIDS): nanoimmunoliposome delivery in vitro and in vivo for RNAi of HER-2

A blunt-ended 19-mer short interfering hybrid (siHybrid) (H) comprised of sense-DNA/antisense-RNA targeting HER-2 mRNA was encapsulated in a liposomal nanoplex with anti-transferrin receptor single-chain antibody fragment (TfRscFv) as the targeting moiety for clinically relevant tumor-specific delivery. In vitro delivery to a human pancreatic cell line (PANC-1) was shown to exhibit sequence-specific inhibition of 48-h cell growth with an IC50 value of 37 nM. The inhibitory potency of this siHybrid was increased (IC50 value of 7.8 nM) using a homologous chemically modified siHybrid (mH) in which the 19-mer sense strand had the following pattern of 2 '-deoxyinosine (dI) and 2 '-O-methylribonucleotide (2 '-OMe) residues: 5'-d(TITIT)-2'OMe(GCGGUGGUU)-d(GICIT). These modifications were intended to favor antisense strand-mediated RNAi while mitigating possible sense strand-mediated off-target effects and RNase H-mediated cleavage of the antisense RNA strand. The presently reported immunoliposomal delivery system was successfully used in vivo to inhibit HER-2 expression, and thus induce apoptosis in human breast carcinoma tumors (MDA-MB-435) in mice upon repeated i.v. treatment at a dose of 3 mg/kg of H or mH. The in vivo potency of modified siHybrid mH appeared to be qualitatively greater than that of H, as was the case in vitro.

Nanotechnology: intelligent design to treat complex disease

The purpose of this expert review is to discuss the impact of nanotechnology in the treatment of the major health threats including cancer, infections, metabolic diseases, autoimmune diseases, and inflammations. Indeed, during the past 30 years, the explosive growth of nanotechnology has burst into challenging innovations in pharmacology, the main input being the ability to perform temporal and spatial site-specific delivery. This has led to some marketed compounds through the last decade. Although the introduction of nanotechnology obviously permitted to step over numerous milestones toward the development of the "magic bullet" proposed a century ago by the immunologist Paul Ehrlich, there are, however, unresolved delivery problems to be still addressed. These scientific and technological locks are discussed along this review together with an analysis of the current situation concerning the industrial development.

Novel Mucosal Insulin Delivery Systems Based on Fusogenic Liposomes

PURPOSE

Fusogenic liposomes (FLs) are unique delivery vehicles capable of introducing their contents directly into the cytoplasm with the aid of envelope glycoproteins of Sendai virus (SeV). The objective of this study was to evaluate the potential of FL to improve the mucosal absorption of insulin from rat intestinal membranes.

METHOD

The FLs containing insulin were prepared by fusing insulin-loaded liposomes with inactivated SeV particles and were administered directly into the ileal, the colonic, and the rectal loops (10 IU/kg).

RESULTS

The FL successfully enhanced the insulin absorption and induced a significant hypoglycemic effect following the colonic and the rectal administration without detectable mucosal damage. This enhancing effect of insulin absorption was further improved by increasing the amount of insulin loaded in the FL and by coencapsulating insulin-degrading enzyme inhibitor. In contrast, the insulin absorption was not increased by the ileal administration of FL because the mucous/glycocalyx layers overlaid on the ileal epithelium impede the fusion of FL to the intestinal mucosa.

CONCLUSION

Our results indicated that FL is a useful carrier for improving the absorption of poorly absorbable drugs, such as insulin, via the intestinal tract.