Efficient nuclear delivery and nuclear body localization of antisense oligo-nucleotides using degradable polymersomes

Polymersome-mediated intracellular delivery of antibiotics to treat Porphyromonas gingivalis-infected oral epithelial cells

The gram-negative anaerobe Porphyromonas gingivalis colonizes the gingival crevice and is etiologically associated with periodontal disease that can lead to alveolar bone damage and resorption, promoting tooth loss. Although susceptible to antibiotics, P. gingivalis can evade antibiotic killing by residing within gingival keratinocytes. This provides a reservoir of organisms that may recolonize the gingival crevice once antibiotic therapy is complete. Polymersomes are nanosized amphiphilic block copolymer vesicles that can encapsulate drugs. Cells internalize polymersomes by endocytosis into early endosomes, where they are disassembled by the low pH, causing intracellular release of their drug load. In this study, polymersomes were used as vehicles to deliver antibiotics in an attempt to kill intracellular P. gingivalis within monolayers of keratinocytes and organotypic oral mucosal models. Polymersome-encapsulated metronidazole or doxycycline, free metronidazole, or doxycycline, or polymersomes alone as controls, were used, and the number of surviving intracellular P. gingivalis was quantified after host cell lysis. Polymersome-encapsulated metronidazole or doxycycline significantly (P<0.05) reduced the number of intracellular P. gingivalis in both monolayer and organotypic cultures compared to free antibiotic or polymersome alone controls. Polymersomes are effective delivery vehicles for antibiotics that do not normally gain entry to host cells. This approach could be used to treat recurrent periodontitis or other diseases caused by intracellular-dwelling organisms.

Antisense therapy in neurology

Antisense therapy is an approach to fighting diseases using short DNA-like molecules called antisense oligonucleotides. Recently, antisense therapy has emerged as an exciting and promising strategy for the treatment of various neurodegenerative and neuromuscular disorders. Previous and ongoing pre-clinical and clinical trials have provided encouraging early results. Spinal muscular atrophy (SMA), Huntington’s disease (HD), amyotrophic lateral sclerosis (ALS), Duchenne muscular dystrophy (DMD), Fukuyama congenital muscular dystrophy (FCMD), dysferlinopathy (including limb-girdle muscular dystrophy 2B; LGMD2B, Miyoshi myopathy; MM, and distal myopathy with anterior tibial onset; DMAT), and myotonic dystrophy (DM) are all reported to be promising targets for antisense therapy. This paper focuses on the current progress of antisense therapies in neurology.

Amphiphilic block co-polymers: preparation and application in nanodrug and gene delivery

Self-assembly of amphiphilic block co-polymers composed of poly(ethylene oxide) (PEO) as the hydrophilic block and poly(ether)s, poly(amino acid)s, poly(ester)s and polypropyleneoxide (PPO) as the hydrophobic block can lead to the formation of nanoscopic structures of different morphologies. These structures have been the subject of extensive research in the past decade as artificial mimics of lipoproteins and viral vectors for drug and gene delivery. The aim of this review is to provide an overview of the synthesis of commonly used amphiphilic block co-polymers. It will also briefly go over some pharmaceutical applications of amphiphilic block co-polymers as "nanodelivery systems" for small molecules and gene therapeutics.

Imaging and drug delivery using theranostic nanoparticles

Nanoparticle technologies are significantly impacting the development of both therapeutic and diagnostic agents. At the intersection between treatment and diagnosis, interest has grown in combining both paradigms into clinically effective formulations. This concept, recently coined as theranostics, is highly relevant to agents that target molecular biomarkers of disease and is expected to contribute to personalized medicine. Here we review state-of-the-art nanoparticles from a therapeutic and a diagnostic perspective and discuss challenges in bringing these fields together. Major classes of nanoparticles include, drug conjugates and complexes, dendrimers, vesicles, micelles, core-shell particles, microbubbles, and carbon nanotubes. Most of these formulations have been described as carriers of either drugs or contrast agents. To observe these formulations and their interactions with disease, a variety of contrast agents have been used, including optically active small molecules, metals and metal oxides, ultrasonic contrast agents, and radionuclides. The opportunity to rapidly assess and adjust treatment to the needs of the individual offers potential advantages that will spur the development of theranostic agents.