Masaru Nakanishi

Effective transfer of interleukin-12 gene to solid tumors using a novel gene delivery system, poly [D,L-2,4-diaminobutyric acid]

Delivery of the interleukin-12 (IL-12) gene to solid tumors is a promising anticancer therapy. Vectors are currently being developed to achieve safe and effective intratumoral delivery of the IL-12 gene. Poly [D,L-2,4-diaminobutyric acid] (PDBA) is a novel gene carrier that was recently described. The goal of this study was to use this gene delivery system for treatment of solid tumors. To determine the optimal conditions for transfection, established B16F10-melanomas in C57BL/6 mice were treated with intratumoral injection of the PDBA/plasmid luciferase (pLuc) complex. We determined that the optimal complex composition was 50 μg/ml pLuc and 150 μg/ml PDBA. High levels of IL-12 protein were expressed in tumors after a single injection of PDBA/murine IL-12 (pmIL-12) complex, whereas serum levels of IL-12 in treated mice were below the limits of detection. IL-12 gene therapy with the PDBA system significantly inhibited tumor growth in comparison with the controls (P<.001). Moreover, both natural killer and cytotoxic T lymphocyte activities from draining lymph nodes of PDBA/pmIL-12-treated mice were increased substantially in comparison with those of controls (P<.05). These results suggest that PDBA-mediated IL-12 gene therapy is a potential strategy for treatment of patients with solid tumors.

Addition of UVA-absorber butyl methoxy dibenzoylmethane to topical ketoprofen formulation reduces ketoprofen-photoallergic reaction.

Topical application of ketoprofen (KP) clinically evokes the allergic type of photocontact dermatitis. To avoid this adverse reaction, we investigated the beneficial effect of each ultraviolet (UV) filter that was included in topical ketoprofen formulation. We first tested the inhibitory effects of four UVA filters by a modified local lymph node assay following KP application on the mouse skin and UVA irradiation on the same site. In this assessment, butyl methoxy dibenzoylmethane (BMDBM), when included in KP application, exerted the most effective inhibitory effect on stimulation with KP and UVA. We manufactured topical patch and gel KP applicants containing BMDBM, which retained KP penetration through the skin and KP stability toward UVA. The ability of BMDBM in these formulations to inhibit KP photosensitivity was evaluated by a modified adjuvant and strip method in guinea pigs, and the photoallergic reactions induced by the BMDBM-containing KP applicants were lower than the non-containing ones. It is known that KP has a cross-reactivity with benzophenone upon UVA exposure, but such a photocross-reactivity of BMDBM with KP was not observed in a mouse ear swelling model. The anti-inflammatory effect of the BMDBM-containing KP patch applicant was comparable to the non-containing one. These results suggest that the addition of BMDBM into KP topical formulations is efficacious for inhibition of KP photocontact dermatitis.

In vivo pharmacokinetics of ketoprofen after patch application in the Mexican hairless pig.

To evaluate the pharmacokinetics of topical drugs, in vitro permeation studies are performed using sacrificed pig skin or human tissues resected at surgery; however, these methods have their limitations in in vivo pharmacokinetics. This study examined the usefulness of Mexican hairless pigs for in vivo pharmacokinetic study, especially the drug concentration in the tissues. A ketoprofen patch was applied on the back of Mexican hairless pigs for 24 h, followed by sequential collection of blood specimens from 0 to 36 h (n=3). Also, the skin, subcutaneous fat, fascia and muscle from the center of the site of application were excised at 12 h after the application (n=4). Ketoprofen was first detected in the plasma at 8 h, the concentration increasing up to 24 h; the plasma concentration began to decrease after the removal of the ketoprofen patch. Ketoprofen concentrations in the tissues decreased with increasing depth of the tissues, but the values in the deep muscles, being the lowest among the tissues examined, were still higher than those in the plasma. While the data of drug concentration in human tissue are difficult to test, the Mexican hairless pig model appears to be attractive for in vivo pharmacokinetic studies of topically applied ketoprofen. Copyright

Serious photocontact dermatitis induced by topical ketoprofen depends on the formulation

BackgroundTopical administration of ketoprofen to treat local subcutaneous pain significantly reduces gastrointestinal and cardiovascular adverse effects associated with oral delivery. However, this benefit must be weighed against the risk of photosensitisation/phototoxicity.ObjectiveTo substantiate the safety and efficacy of topical ketoprofen delivery from a patch.MethodsExperiments were performed, and published information analysed, (a) to confirm the superior skin permeability and pharmacological activity of ketoprofen, and (b) to demonstrate the lower incidence of ketoprofen photosensitisation/phototoxicity when delivered from a topical patch.ResultsKetoprofen’s photodegradation products were more photoallergic than the drug itself. The period postketoprofen treatment that skin should be protected from UV radiation (while the drug is cleared from the application site) was estimated.ConclusionsPhotosensitisation to ketoprofen can be mitigated by a patch formulation, which protects the drug from direct UV exposure during skin application, and reduces the formation of even more photoallergic photodegradation products.