Current Pharmaceutical Design - Volume 23, Issue 40, 2017

Background: Although medications should only be prescribed in pregnancy if benefits to the mother outweigh the risk to the fetus, drug use in pregnancy especially prescribed and over-the-counter analgesics, is very common. Objective: The objective of this review is to present an update on known changes in analgesic disposition in pregnancy caused by pharmacokinetic mechanisms. Method: Herein, we discuss a wide range of medical, biomedical and scientific literature that includes reports from the fields of dentistry, general medicine, obstetrics and gynecology, pharmacology and toxicology to provide an update on the use (including indications, contraindications and concerns) of major classes of analgesics during human pregnancy. Results: Over 50% of analgesics are in pregnancy category C, and even more category D specifically in the third trimester. Changes in renal filtration, cardiac output, plasma protein concentration and plasma volume particularly affect analgesics and dose adjustments may be necessary to maintain therapeutic concentrations in pregnant woman, and/or to protect the developing fetus. Conclusion: Analgesics are one of the most frequently used drug classes in pregnancy. More than 60% of women self-report using analgesics while pregnant, both prescribed and by self-medication. For the majority of analgesics available (excepting acetaminophen and the NSAIDs, and to a lesser extent certain opioids), good prospective clinical trials documenting pharmacokinetic changes do not exist. More research is needed in both the scientific and clinical community to understand the risks and benefits of analgesic use in pregnancy, particularly as prevalence is rising.

Preterm birth (PTB) is clinically defined as process of giving birth before 37 weeks of gestation and is a leading cause of death among neonates and children under the age of five. Prematurity remains a critical issue in developed countries, yet our understanding of the pathophysiology of PTB remains largely unknown. Among pregnancy complications, subclinical infections such as chorioamnionitis (CAM) are implicated in up to 70% of PTB cases. Specifically, CAM is characterized by the infection of the fetal membranes that surround the developing fetus and extend from the placenta, and is often associated with preterm, premature rupture of the fetal membranes (PPROM). The fetal membrane plays a key structural role in maintaining the fetal and maternal compartments of the gravid uterus. However, our understanding of the mechanisms of PPROM and the spatio-temporal progress of CAM remains vastly unknown. A lack of human-derived models have hindered our understanding of the mechanism that govern spontaneous PTB. Thus, in this short review, we discuss the emerging microfabrication technologies, specifically, organ-on-chip (OoCs) models, that seek to recapitulate the cellular and molecular context of the gestational membranes in vitro. These models show promise to facilitate the investigation of pathologic mechanisms that drive these disease conditions by mimicking the interactive contribution of the major cell types that make up the microenvironment of the fetal membrane and enable high throughput screening. Herein, we histologically characterize the microenvironment of the fetal membrane as a metric for scaling to recapitulate the functional components of the human fetal membrane. We review the current OoC models of the gravid uterus and conceptualize an “Instrumented Fetal Membrane on a Chip” (IFMOC) design as a prototype for PPROM and CAM research. Lastly, we discuss further applications of these OoC models for toxicological or pharmacological screening and personalized medicine. Fetal membrane OoCs offer an innovative and valuable platform to explore complex interactions between multiple drug types, toxic substances, and/or pathogenic microbes and their potential impacts on pregnancy outcomes. Further work will be required by integrating technological and analytical capabilities in order to characterize the fetal membrane microenvironment for preterm birth research.

Preterm birth and associated prematurity-related morbidity can significantly affect neonatal health and outcomes. While the mechanisms of preterm labor are yet to be fully understood, there is a need for prenatal therapeutic interventions to treat these conditions. As it is recognized from literature, the immune mechanisms responsible for preterm labor may be different from those responsible for prematurity-related conditions in the neonate. Differentiating the mechanisms for these two processes is yet to be addressed, and steps need to be taken to move forward the new field of immune-perinatology. One class of treatment is immunotherapy to target the immune modulators involved in preterm labor and its sequelae. This paper focuses on reviewing existing literature on studying the efficacy of maternal immunomodulatory therapy on preventing preterm birth and prematurity- related adverse outcomes in the newborn.

Preterm birth (PTB) is a leading cause of neonatal mortality and morbidity worldwide, and surviving infants are at increased risks of lifelong complications. PTB has been firmly linked to inflammation regardless of infection, specific aetiology or timing of birth. Deleterious inflammation is observed in maternal and fetal tissue, and correlates with the severity of perinatal complications. At present, PTB is treated with tocolytics as though it is exclusively a myometrial contractile disorder. These agents do not address underlying inflammatory processes and are thus vastly ineffective at improving neonatal outcomes. Of all inflammatory mediators, IL-1 is central to the pathophysiology of PTB and most adverse neonatal outcomes. We thus present herein a review of the various effects of IL-1 in utero, with a brief overview of its mechanism of action. We then discuss the potential of different IL-1-targeting agents based on pre-clinical testing in relevant models of PTB and neonatal inflammatory injuries.

Background: Preterm birth (PTB) is a multifactorial syndrome occurring before the 37th week of fullterm pregnancy [1]. Babies delivered preterm experience short-term and long-term complications affecting multiple organ systems, and serious maternal complications include hemorrhage and infection. Each year, an estimated 15 million babies are born preterm, and complications from prematurity are the leading cause of death among children up to 5 years of age [2]. With another increase in PTB rates over the last several years, the United States continues to have the highest incidence of any industrialized country [3]. Makena (a progesterone analog) is the only FDA approved medication available in the United States to reduce the risk of PTB. Its use is only indicated in women who are currently pregnant with one fetus and have unexpectedly delivered a baby preterm in the past [4]. Furthermore, Makena is very expensive and not used in mothers with multiple gestations or other risk factors, such as infection, preeclampsia and obesity. Consequently, physicians commonly prescribe supportive therapies, such as magnesium sulfate, to slow uterine contractions, and glucocorticoids to stimulate fetal lung maturity. Methods: In this article, we review the full spectrum of in vivo models that investigators have developed to study PTB, including rodent, ruminant and non-human primate models. We evaluate the discrepancies among various models, the shortcomings of individual models and how well these models reflect various causes of PTB in humans. Results: Recent studies reveal that infection is unessential in reproductive disorders linked to inflammation, and that infection and inflammation are two of many triggers of PTB [1, 5-6]. Despite such findings, many investigators continue recycling infectious- (using bacterium) and non-infectious-based models (using products of bacteria or individual cytokines). These models are inconsistent across laboratories, and produce variable degrees of maternal morbidity (inconsistent with human PTB). Conclusion: The aim of this review is to encourage the reproductive science community to rethink the design of non-infectious PTB animal studies. While these models have strengthened our understanding of the mediators and triggers of PTB, we must develop improved models that are more consistent with the various factors associated with human PTB (Fig. 1). If we continue viewing PTB through one lens or dimension, Makena will remain the only FDA approved medication. In vivo PTB research requires multi-model, multifactorial approaches that account for the complexity of living animals within and between species.

Diverse histone deacetylase (HDAC) inhibitors have been developed to date. They control not only histone modification but also gene expression of diverse proteins and thus are expected to provide useful therapeutic effects on various diseases, including cancers, psychiatric and cognitive disorders and neurodegenerative diseases, as well as cardiovascular and diabetic diseases. Some isoform-nonselective HDAC inhibitors have been successfully used for clinical treatments of the haematological malignancies, including advanced forms of cutaneous T-cell lymphoma, refractory peripheral T-cell lymphoma and multiple myeloma. However, the nonselective HDAC inhibitors threaten to cause adverse effects, such as thrombocytopenia, nausea, fatigue and cardiotoxicity, and their influence on the health care of patients is of concern. It is therefore anticipated that the development of isoform-selective HDAC inhibitors may offer more efficacy and less toxicity. Recently, a number of 5- aryl-substituted 2-aminobenzamide series of HDAC1/2-selective inhibitors have been synthesized, and their useful biological activities have been reported. In this review, we introduce the recent development of synthetic and biological studies on 5-aryl-substituted 2-aminobenzamide-type HDAC1/2 inhibitors, together with the latest research findings on biology of broad-spectrum HDAC inhibitors. In addition, we refer to the possibility of their application in clinical therapies.

Despite the value of vaccination, the control of re-emerging infectious and non-infectious diseases remains a challenge for researchers. In this topic, mucosal immunization, in particular at airway mucosa, is receiving increased investigational focus. Innovative vaccine platforms to deliver immunogens with or without adjuvants in a safe and stable manner have been explored to improve vaccine efficacy and induce long-term and protective immunity. This review provides an overview of the features of respiratory immunization and the fate of inhalable nanocarriers in the respiratory tract. The review also highlights the most representative delivery approaches based on inhalable nanocarriers, including polymeric, lipid and inorganic-based nanosystems, which can enhance vaccine uptake by antigen-presenting cells. The review takes into consideration the most relevant and recent in vivo studies to provide readers a realistic insight into the potential of these technologies in the advantages and potential hurdles to clinical and commercial success of these platforms for vaccination.

Background: Atherosclerosis is the leading cause of death and morbidity throughout industrialized nations, accounting for one-fifth of all deaths globally. Exosomes are bi-lipid membranous vesicles containing protein, lipid and nucleic acid contents that are released from the cells via the endolysosomal pathway. Exosomes are derived from several cells including macrophages, dendritic cells, platelets as well as human serum. Methods: In this review, an overview of recent advances, the evidence for the role of exosomes and exosomederived microRNAs (miRNAs) in atherosclerosis are provided. Results: Recent evidence has shown that exosomes derived from the cells mentioned above are involved in atherosclerosis, whose secretion appears to be regulated by various natural and experimental stimuli, physiological and pathological processes. Conclusion: Exosomes are now accepted as specifically secreted vesicles that enable intercellular communications and have become exponentially interesting to be used as the possible relevant biomarkers in disease development such as cadiovascular disease, particular in atherosclerosis in addition to their minimally invasive clinical diagnosis.

Photodynamic therapy is an evolving treatment modality for cancer owing to its non-invasive approach. This mode of therapy depends on the dynamic interaction of light, oxygen and a photoactive drug to induce oxidative damage to affected cells. This apparently simple technique could be complicated by several factors, mainly contributed by the nature of the physicochemical properties of the photoactive drug, variation in light source and exposure time, as well as tumor physiological environment. This review covers a brief history on the use of various fluorophores in photodynamic therapy, successful marketed formulations and the factors affecting the treatment modalities. The potential of nanostructures as effective delivery carriers with improved photodynamic efficacy is also elaborated. A thorough understanding of the chemistry of photoactive drugs, characteristics of the delivery carriers and light irradiation parameters will enable optimal efficacy of photodynamic therapy.

Recently, extracellular vesicles (EVs), like exosomes and microvesicles, have attracted attention as potent carriers of intercellular communication throughout the body, including the brain. They transmit biological signals from donor cells to recipient cells, and recent evidence suggests that they may even carry such signals to distant destinations through peripheral circulation. In the central nervous system (CNS), EVs contribute to maintaining normal neuronal function, as well as to the pathological development of neurodegenerative diseases. Although some evidence has suggested that EVs can cross the blood-brain barrier (BBB), moving from the peripheral circulation to the CNS, the mechanisms by which EVs facilitate communication between peripheral tissues and the CNS are not well understood. The BBB is a dynamic interface that regulates molecular trafficking between the peripheral circulation and the CNS. However, there is limited mechanistic understanding of how bloodborne EVs cross the BBB under physiological and pathological conditions. In this review, we focus on current knowledge of trafficking of EVs between the peripheral circulation and the brain. Moreover, we describe hypothetical transport routes by which EVs may cross the BBB based on previous reports. Further investigation is needed to understand the precise mechanisms by which EVs are transported across the BBB.

NO produced by eNOS plays important roles in the cardiovascular system. Alterations in eNOS activity and expression occur in various cardiovascular disorders and eNOS constitutes a therapeutic target. In addition to posttranslational modifications of eNOS that affect eNOS activity, transcriptional and post-transcriptional regulation of eNOS expression also controls eNOS-derived NO production. Bradykinin is an important determinant of vascular function and participates in the regulation of eNOS activity and expression. A number of currently used drugs or investigational molecules targeting specific ion channels, enzymes or receptors, including dihydropyridine calcium channel blockers, angiotensin-converting enzyme inhibitors, statins, AT1 receptor blockers and angiotensin-(1-7), increase eNOS expression and activity. In this context, activation of bradykinin B2 receptors appears to be a common step for these drugs to promote eNOS expression, which certainly contributes to their therapeutic actions.

Antioxidants have the potential to prevent cerebral ischemia-reperfusion (IR)-associated secondary damage induced by reactive oxygen species (ROS); however, the short therapeutic time window of IR is a considerable obstacle. Nano-sized nasal delivery systems provide an effective means of delivering drugs through the BBB, but few such systems have been developed to extend the treatment time window in IR. In this work, a nanosized nasal delivery system for antioxidants was found to have the potential to extend the neuroprotective time window. The authors chose to use the antioxidant C-phycocyanin (C-Pc) to design a neuroprotective liposome with a long life, controllable release, and high neuronal uptake rate. Liposomes formulated with various cholesterol to phospholipid ratios were assessed thermodynamically, kinetically, and biologically. Thermodynamically stable, monodispersive, and release-controllable C-Pc liposomes were more effectively taken up by Neuro2a cells than free C-Pc and were biocompatible, maintaining the anti-oxidative properties of C-Pc. When optimal C-Pc liposomes were administered to middle cerebral artery occlusion (MCAO) rats 2 h after onset, infarct sizes were smaller and behavioral activities improved compared with the same metrics in free C-Pc-treated rats. Liposomal delivery still reduced infarct sizes and improved behavioral activity 6 h after onset, whereas free C-Pc did not.

The rare, chronic, autosomal-recessive lysosomal storage disease Niemann-Pick disease type C1 (NPC1) is characterized by progressively debilitating and ultimately fatal neurological manifestations. There is an urgent need for disease-modifying therapies that address NPC1 neurological pathophysiology, and passage through the blood-brain barrier represents an important consideration for novel NPC1 drugs. Animal investigations of 2-hydroxypropyl-β-cyclodextrins (HPβCD) in NPC1 in mice demonstrated that HPβCD does not cross the blood-brain barrier in significant amounts but suggested a potential for these complex oligosaccharides to moderately impact CNS manifestations when administered subcutaneously or intraperitoneally at very high doses; however, safety concerns regarding pulmonary toxicity were raised. Subsequent NPC1 investigations in cats demonstrated far greater HPβCD efficacy at much lower doses when the drug was administered directly to the CNS. Based on this, a phase 1/2a clinical trial was initiated with intrathecal administration of a specific, wellcharacterized mixture of HPβCD, with a tightly controlled molar substitution specification and a defined molecular “fingerprint” of the different species. The findings were very encouraging and a phase 2b/3 clinical trial has completed enrollment and is underway. In addition, phase 1 clinical studies utilizing high-dose intravenous administration of a different HPβCD are currently recruiting. Independent studies are needed for each product to satisfactorily address questions of safety, efficacy, dosing, and route of administration. The outcomes cannot be assumed to be translatable between HPβCD products and/or routes of administration.