Gene therapy by electroporation for the treatment of chronic renal failure in companion animals

<p>Abstract</p> <p>Background</p> <p>Growth hormone-releasing hormone (GHRH) plasmid-based therapy for the treatment of chronic renal failure and its complications was examined. Companion dogs (13.1 ± 0.8 years, 29.4 ± 5.01 kg) and cats (13.2 ± 0.9 years, 8.5 ± 0.37 kg) received a single 0.4 mg or 0.1 mg species-specific plasmid injection, respectively, intramuscularly followed by electroporation, and analyzed up to 75 days post-treatment; controls underwent electroporation without plasmid administration.</p> <p>Results</p> <p>Plasmid-treated animals showed an increase in body weight (dogs 22.5% and cats 3.2%) compared to control animals, and displayed improved quality of life parameters including significant increases in appetite, activity, mentation and exercise tolerance levels. Insulin-like growth factor I (IGF-I, the downstream effector of GHRH) levels were increased in the plasmid treated animals. Hematological parameters were also significantly improved. Protein metabolism changes were observed suggesting a shift from a catabolic to an anabolic state in the treated animals. Blood urea nitrogen and creatinine did not show any significant changes suggesting maintenance of kidney function whereas the control animal's renal function deteriorated. Treated animals survived longer than control animals with 70% of dogs and 80% of cats surviving until study day 75. Only 17% and 40% of the control dogs and cats, respectively, survived to day 75.</p> <p>Conclusion</p> <p>Improved quality of life, survival and general well-being indicate that further investigation is warranted, and show the potential of a plasmid-based therapy by electroporation in preventing and managing complications of renal insufficiency.</p

Enhancing the efficacy of cytotoxic agents for cancer therapy using photochemical internalisation.

Photochemical internalisation (PCI) is a technique for improving cellular delivery of certain bioactive agents which are prone to sequestration within endolysosomes. There is a wide range of agents suitable for PCI-based delivery including toxins, oligonucleotides, genes and immunoconjugates which demonstrates the versatility of this technique. The basic mechanism of PCI involves triggering release of the agent from endolysosomes within the target cells using a photosensitiser which is selectively retained with the endolysosomal membranes. Excitation of the photosensitiser by visible light leads to disruption of the membranes via photooxidative damage thereby releasing the agent into the cytosol. This treatment enables the drugs to reach their intended subcellular target more efficiently and improves their efficacy. In this review we summarise the applications of this technique with the main emphasis placed on cancer chemotherapy

Novel Vaccines to Human Rabies

Rabies, the most fatal of all infectious diseases, remains a major public health problem in developing countries, claiming the lives of an estimated 55,000 people each year. Most fatal rabies cases, with more than half of them in children, result from dog bites and occur among low-income families in Southeast Asia and Africa. Safe and efficacious vaccines are available to prevent rabies. However, they have to be given repeatedly, three times for pre-exposure vaccination and four to five times for post-exposure prophylaxis (PEP). In cases of severe exposure, a regimen of vaccine combined with a rabies immunoglobulin (RIG) preparation is required. The high incidence of fatal rabies is linked to a lack of knowledge on the appropriate treatment of bite wounds, lack of access to costly PEP, and failure to follow up with repeat immunizations. New, more immunogenic but less costly rabies virus vaccines are needed to reduce the toll of rabies on human lives. A preventative vaccine used for the immunization of children, especially those in high incidence countries, would be expected to lower fatality rates. Such a vaccine would have to be inexpensive, safe, and provide sustained protection, preferably after a single dose. Novel regimens are also needed for PEP to reduce the need for the already scarce and costly RIG and to reduce the number of vaccine doses to one or two. In this review, the pipeline of new rabies vaccines that are in pre-clinical testing is provided and an opinion on those that might be best suited as potential replacements for the currently used vaccines is offered

Electroporation to deliver plasmid DNA into rat dental tissues

BACKGROUND: Delivery of DNA into the target tissues is an important technique in gene function studies and gene therapy. Surgical treatment of tooth eruption disorders, such as impacted third molars, is a major health care cost. Because the dental follicle (DF) is essential for regulating tooth eruption, establishment of local gene transfer protocols is needed to determine the effect of various genes on eruption and to develop gene therapy approaches to induce the eruption of impacted molars. METHODS: Plasmids containing lacZ reporter gene were injected into rat mandibles and then electroporated at the designated settings. Mandibles were collected 24 hours after electroporation for X-gal staining to evaluate the transfection efficiency. Tissues were collected at various days post-electroporation to determine the expression of the transgene. RESULTS: For the DF, depth of injection and pulse number appear to be important. Six pulses can achieve above 80% transfection of the DF at 50V or 120V. For AB transfection, voltages are important with 120V being optimal. Regarding pulse durations, we determined that durations of 20 ms and 30 ms achieve the maximum transfection in AB and DF, respectively. CONCLUSIONS: This study demonstrates for the first time the feasibility of electroporation to locally deliver plasmids into dental tissues. Parameters affecting electroporation to deliver plasmids into the dental tissues were optimized. This protocol could be used to deliver shRNA or genes of interest into the dental tissues to regulate tooth eruption. Thus, it may be possible to develop non-surgical treatments for inducing eruption of impacted teeth