Oligonucleotides (ONs) are a new class of therapeutic compounds under investigation for the treatment of a variety of disease states, such as cancer and HIV, and for FDA approval of an anti-CMV retinitis antisense molecule (Vitravene trade mark, Isis Pharmaceuticals). However, these molecules are limited not only by poor cellular uptake, but also by a general lack of understanding regarding the mechanism(s) of ON cellular uptake. As a result, various delivery vehicles have been developed that circumvent the proposed mechanism of uptake, endocytosis, while improving target specific delivery and/or drug stability. This review describes various traditional and novel delivery mechanisms that have been employed to improve ON cellular delivery, cost effectiveness, and therapeutic efficacy.

Traditionally, methadone maintenance therapy has been a once-daily dosing schedule. The current study evaluates the effectiveness of this regimen during pregnancy. A total of 23 pregnant and 16 non-pregnant opioid-dependent patients were studied in two phases to evaluate pregnancy-dependent changes in methadone pharmacokinetics. In the first phase, pregnant patients had a statistically significant higher elimination rate constant (k) and lower half-life compared to non-pregnant controls. In the second phase, the apparent clearance (Cl/F) was significantly greater during pregnancy, with preliminary data suggesting that this observation results from a decrease in the fraction of dose absorbed (F). The implications of these findings on dosing regimens during pregnancy is discussed.

Antisense oligonucleotides have therapeutic potential as inhibitors of gene expression. However, the mechanism by which an intact oligonucleotide reaches the intracellular site of action is unknown. In this study, we use an oligodeoxyribonucleotide 21-mer complementary to the translation initiation codon of the c-myc protooncogene to study the mechanism of oligonucleotide uptake and internalization into Rauscher Red 5-1.5 cells. We find trypsin-sensitive and trypsin-insensitive surface binding, in addition to internalization. Uptake is partially energy dependent and inhibited by charged molecules, including DNA, ATP, a random sequence oligonucleotide, and dextran sulfate. Uptake does not appear to occur via a traditional receptor-mediated uptake pathway because chloroquine, monensin, and phenylarsine oxide pretreatment does not significantly decrease internalization. An anion channel inhibitor, SITS, and the salts, NaCl, Na2SO4, and NH4Cl, significantly decrease oligonucleotide uptake. Whether uptake occurs via a channel or a novel uptake mechanism is still unknown. A model is proposed which reasonably simulates the experimental data.

Despite pharma's recent sea change in approach to drug discovery and development, U.S. pharmaceutical sciences graduate programs are currently maintaining traditional methods for master's and doctoral student education. The literature on graduate education in the biomedical sciences has long been advocating educating students to hone soft skills like communication and teamwork, in addition to maintaining excellent basic skills in research. However, recommendations to date have not taken into account the future trends in the pharmaceutical industry. The AACP Graduate Education Special Interest Group has completed a literature survey of the trends in the pharmaceutical industry and graduate education in order to determine whether our graduate programs are strategically positioned to prepare our graduates for successful careers in the next few decades. We recommend that our pharmaceutical sciences graduate programs take a proactive leadership role in meeting the needs of our future graduates and employers. Our graduate programs should bring to education the innovation and collaboration that our industry also requires to be successful and relevant in this century.

Previously described cell membrane transport mechanisms are unable to account completely for oligodeoxynucleotide cellular uptake. These charged macromolecules enter cells by an incompletely defined mechanism and downregulate gene expression in either the cytoplasm or nucleus. Thus, the goal of this research was to study the mechanism of phosphodiester oligonucleotide cellular uptake in Rauscher Red 5-1.5 erythroleukemia cells. An antisense c-myc oligodeoxynucleotide (21 bases) demonstrated biological activity in these cells using two types of proliferation assays and Northern blot analysis, and was internalized as visualized by confocal laser microscopy. Oligonucleotide uptake appeared to be a complex process consisting of surface binding and internalization. Cellular internalization accounted for up to 40% of total uptake and was partially dependent on both a trypsin-sensitive component and cellular energy. Uptake in these cells was nonspecific and did not appear to be due to receptor-mediated endocytosis. Therefore, because oligonucleotide cellular uptake in other cell types apparently involves an endocytic mechanism, the primary mechanism of oligonucleotide internalization may be cell line dependent.