Current Pharmaceutical Design - Volume 24, Issue 15, 2018

Background: Anticancer chemotherapeutics have a lot of problems via conventional Drug Delivery Systems (DDSs), including non-specificity, burst release, severe side-effects, and damage to normal cells. Owing to its potential to circumventing these problems, nanotechnology has gained increasing attention in targeted tumor therapy. Chemotherapeutic drugs or genes encapsulated in nanoparticles could be used to target therapies to the tumor site in three ways: “passive”, “active”, and “smart” targeting. Objective: To summarize the mechanisms of various internal and external “smart” stimulating factors on the basis of findings from in vivo and in vitro studies. Method: A thorough search of PubMed was conducted in order to identify the majority of trials, studies and novel articles related to the subject. Results: Activated by internal triggering factors (pH, redox, enzyme, hypoxia, etc.) or external triggering factors (temperature, light of different wavelengths, ultrasound, magnetic fields, etc.), “smart” DDSs exhibit targeted delivery to the tumor site, and controlled release of chemotherapeutic drugs or genes. Conclusion: In this review article, we summarize and classify the internal and external triggering mechanism of “smart” nanoparticle-based DDSs in targeted tumor therapy, and the most recent research advances are illustrated for better understanding.

Technetium (99mTc)-radiolabeled colloids are popular tracers used to map lymphatic vessels and regional lymph nodes (LNs). The regional LN status is a significant determinant of cancer stage and patient prognosis, and strongly influences treatment. Regional LN dissection has become a part of surgical treatment. However, not all patients with LN involvement benefit from extensive lymphadenectomy in terms of prolonged survival. Moreover, overtreatment of patients with localized disease carries the unnecessary risk of complications. It is believed that sentinel LN biopsy (SLNB) allows to assess the involvement of the most representative LN of the lymphatic basin and to decide on radical LN dissection.99mTc is an easily available radionuclide emitting gamma rays. The value of 99mTc for diagnostic procedures is associated with its relatively short half-life that makes it safe both for patients and medical personnel. A colloid presenting specific physical and biological properties, including optimal particle size, is a carrier for the radionuclide. When administered at the tumor site, a radiocolloid is absorbed by the lymphatics, and the first LN that it gets trapped in is referred to as the sentinel LN (SLN). The radiopharmaceutical must reach the SLN relatively quickly, but its storage within the SLN, and the radionuclide's half-life must be long enough to enable intraoperative imaging and evaluation. SLNB is currently the gold standard in breast cancer and malignant melanoma diagnosis, and is under extensive investigation in gynecological cancers. Here, we provide a historical perspective of the SLN concept and the clinical relevance of SLNB in gynecologic oncology. Moreover, we review the technical aspects of the application of 99mTc-based radiopharmaceuticals in lymphoscintigraphy and intraoperative lymphatic mapping.

Background: The HERC family contains six members from HERC1 to HERC6 that are featured with the HECT domains that exerts ubiquitin ligase activity and the RCC1-like domains that are involved in cell cycle regulation. Although identified as early as 1990s, their biological functions are extensively studied in recent years. More and more researches have demonstrated that the HERC ubiquitin ligases are widely engaged in carcinogenesis, however, there lacks a comprehensive and instructive analysis. Methods: The PubMed database was searched by keywords of individual HERC proteins (such as HERC4) and cancer. The emerging roles of HERC proteins in cancer and the specific mechanisms were collectively analyzed and discussed. Results: HERC proteins belong to the HECT domain-containing ubiquitin ligases that can identify and mediate the ubiquitination of specific substrate proteins. All HERC ubiquitin ligases except HERC6 have been assigned one or more than one ubiquitination substrates. In all of HERCs, HERC1 and HERC2 have been widely studied, in contrast, there are no reported studies yet on protein ubiquitination mediated by HERC6. Dependent on the protein substrates, HERC proteins may act as a tumor suppressor or oncoprotein in specific cancer types. For example, HERC4 is believed to contribute to carcinogenesis of solid tumors such as lung cancer, but it suppresses the proliferation of myeloma cells. Conclusion: HERC proteins as ubiquitin ligases are widely involved in various cancers. Targeting at specific HERC proteins could be a strategy for the treatment of certain cancers.

Introduction: Although a great many strategies have been proposed for tumor-targeted chemotherapy, current delivery methods of anticancer drugs present limited success with inevitable systemic toxicity. The aim of this study was to develop a new kind of theranostic carrier for targeted tumor therapy. Methods: Prior to prepare CHC-PFP-DOX, carboxymethyl-hexanoyl chitosan (CHC) was synthesized by acylation of carboxymethyl chitosan. To develop CHC-PFP, perfluoropentane (PFP), an ultrasound gas precursor, was simultaneously encapsulated into the hydrophobic inner cores of pre-formulated CHC micelle in aqueous phase via using the oil in water (O/W) emulsion method. The size distribution and surface charges of these nanodroplets were measured and the morphology was observed by transmission electron microscopy (TEM). For ultrasound imaging application, in vitro model was established to evaluate the imaging of CHC-PFP-DOX under different concentration and mechanical index. After that, the anti-tumor effect of ultrasound combined with CHC-PFPDOX on ovarian cancer cells was investigated. Results: The resulting CHC-PFP-DOX had a nano-sized particle structure, with hydrophobic anticancer DOX/PFP inner cores and a hydrophilic carboxymethyl chitosan polymer outer shell. The favorable nano-scaled size offers the potential to extravagate from veins and accumulate in tumor tissues via enhanced permeation and retention (EPR) effect. Additionally, CHC-PFP-DOX showed the ability to serve as ultrasound imaging agent at body temperature. Notably, it exhibited an ultrasound-triggered drug release profile through the external ultrasound irradiation. Further study demonstrated that ultrasound combined with CHC-PFP-DOX can improve the killing effect of chemotherapy for tumor. Conclusion: CHC-PFP-DOX holds great promise in simultaneous cancer-targeting ultrasound imaging and ultrasound- mediated delivery for cancer chemotherapy.

Background: In vitro tests allow establishing experimental variables. However, in vitro results cannot be extrapolated to in vivo tests. Considering that three-dimensional (3D) culture has been one of the best ways to portray the in vivo system of most cell types, it is possible to carry out assays with a great clinical relevance for the analysis of the screening, action and resistance of antitumor drugs. Objective: Thus, the objective of the present study was to compare between 2D and 3D cell culture forms to conclude which is the most suitable model for preclinical in vitro drug testing. Method: We evaluated the proliferation, genetic expression and chemoresistance of prostate tumor cell lines, PC- 3, LNCaP and DU145. Prostate tumor cell lines PC-3, LNCaP and DU145 were treated with the antineoplastic drugs paclitaxel and docetaxel and evaluated with cytotoxicity, cell proliferation and gene expression assays in 2D and magnetic 3D bioprinting cultures. Results: Lower cell proliferation rate, more resistance to paclitaxel and docetaxel and altered gene expression profile was shown in 3D cell culture comparing with its 2D counterpart. Conclusion: 3D cell culture exhibited a more similar behavior to in vivo systems, being a promising and more reliable tool for the development of new drugs.

Diabetes mellitus (DM) is the most commonly occurring cause of neuropathy around the world and is beginning to grow in countries where there is a risk of obesity. DM Type II, (T2DM) is a common age-related disease and is a major health concern, particularly in developed countries in Europe where the population is aging. T2DM is a chronic disease which is characterised by hyperglycemia, hyperinsulinemia and insulin resistance, together with the body's inability to use glucose as energy. Such metabolic disorder produces a chronic inflammatory state, as well as changes in lipid metabolism leading to hypertriglyceridemia, thereby producing chronic deterioration of the organs and premature morbidity and mortality. The pathology's effects increase cerebral damage, leading to the rapid onset of neurodegenerative diseases. Hyperglycemia causes oxidative stress in tissues which are susceptible to the complications involved in diabetes, including peripheral nerves. Other additional mechanisms include activation of polyol aldose reductase signalling accompanied by protein kinase C (PKC)-ß activation, poly(ADP ribose) polymerase activation, cyclooxygenase (COX) 2 activation, endothelial dysfunction, altered Na+/K+ ATPase pump function, dyslipidaemia and perturbation of calcium balance. All the forgoing has an impact on neuron activity, mitochondrial function, membrane permeability and endothelial function. These biochemical processes directly affect the neurons and endothelial tissue, thereby accelerating cerebral aging by means of peroxidation of the polyunsaturated fatty acids and thus injuring cell membrane integrity and inducing apoptosis in the glial cells. The Central Nervous System (CNS) includes two types de glial cells: microglia and macroglia (astrocytes, oligodendrocytes and radial cells which include Bergmann cells and Müller cells). Glial cells constitute more than 90% of the CNS cell population. Human studies have shown that some oral antidiabetic drugs can improve cognition in patients suffering mild cognitive impairment (MCI) and dementia [1, 2]. While it is still unclear whether diabetes management will reduce MCI and Alzheimer's disease (AD), incidence, emerging evidence suggests that diabetes therapies may improve cognitive function. This review focuses three aspects: the clinical manifestation of diabetes regarding glial and neuronal cells, the association between neurodegeneration and diabetes and summarises some of the pharmacogenomic data obtained from studies of T2DM treatment, focusing on polymorphisms in genes affecting pharmacokinetics, pharmacodynamics and treatment outcome of the most commonly-prescribed oral anti-diabetic drugs (OADs).

In addition to external factors, such as exercise, food and the environment, genetic predisposition makes great contribution to the development of metabolic disorders and cardiovascular disease. This review is aimed to examine the genetic basis of complex metabolic disorders conventionally described as "metabolic syndrome" (MetS), with the special focus on currently known mutations in the nuclear and mitochondrial genomes, which are associated with both the individual components of MetS and combinations thereof, and also on the studies of the relationship of MetS phenotype as a binary trait. The defects in the mitochondrial genome should be considered as one of the possible genetic reasons leading to MetS. It is known that mitochondrial dysfunction is closely associated with metabolic disorders, as mitochondria are the center of energy metabolism. Consequently, the changes in mitochondrial genes and their functions affect regulation of metabolism. Until now, the role of mitochondrial DNA damage in the development of cardiovascular diseases, age-related and metabolic disorders is still poorly understood. The results of performed studies would help assessing the role of mitochondrial DNA mutations in susceptibility to metabolic syndrome and related metabolic diseases.

Background: Genetic alterations cause Hereditary Diseases (HDs) with a wide range of incidences. Some, like cystic fibrosis, occur frequently (1/1,000 newborns), whilst others, such as Pompe disease and other metabolic disorders are very rare (1/100,000 newborns). They are well under the threshold of 1/3,000, denoted by the European Community as Rare Diseases (RDs). Genetic alterations are also associated with multifactorial disorders like diabetes, and underline both somatic and germline mutations in cancer. Nowadays, thanks to the interventions of the European Union and the American National Health Institute as well as others, Hds are under an international lense, which has stimulated discussions and research targeting gene identification, prenatal diagnosis and care optimization leading to the development of new treatment options. Nanomedicine is paving the way toward some highly appealing clinical and research avenues in HDs. Nanotechnologies lend themselves to many aspects in human healthcare, such as in vitro diagnostics (nanobiosensors and nanoplatforms), drug delivery (nanovectors), drug monitoring (nanosensors) and artificial organs to study the genome variant meaning (nanostructures). Methods and Results: With a significant reduction in costs and simplified healthcare delivery, nanodiagnostics can potentially provide the tools to diagnose diseases at an early stage with precision. In vitro nanodiagnostics are already diagnosing RDs, with many nanodevices having been successfully introduced over the last few decades. Nanovectors represent an emerging approach in drug delivery and treatment for several diseases such as cancers, infectious diseases, cardiovascular disorders and neurological pathologies. Artificial tissues have valuable implications in replacing compromised organs, thus offering unique opportunities to explore pathogenic mechanisms as well as new drug targets in a personalized context. Conclusion: This article outlines and discusses the recent progress in nanotechnology and its potential applications in HDs. It is a pivotal field for research and innovation in healthcare, with emphasis on diagnostics, disease monitoring, biomarker assaying and drug delivery. We underlined the nanomethod's capacity to identify genetic alterations and the follow up of important aspects of the disease course, including therapies. We extensively described the new field of nanodelivery for experimental drugs, focusing on new genetic therapies and their implications in hereditary disorders. We also detailed innovative tools as artificial tissues based on nanomatrices and their use to identify or study genetic alterations.

Glial cells (also known as glia or neuroglia) are structures which are found in large numbers throughout the nervous system, fulfilling multiple functions, such as regulating the synapses, providing structure, support and nutrition, contributing towards the immune response and tissue oxygenation. Knowledge regarding glial cells has increased during the last few years, since Virchow defined them as supporting connective tissue, followed by Ramón y Cajal who described them as tissue in themselves, until today when a first order physiological role has been recognised for them and a leading role in the appearance and progression of various pathological processes, primarily in the group of Neurodegenerative Diseases (ND). The ND represents a group of pathologies which gradually cause the degeneration of nervous tissue, have a broad spectrum regarding their appearance and, in some cases, are the direct consequence of genetic alterations leading to physiological changes in the nervous system. The present article has thus been aimed at describing glial cells' genetic interaction with ND through a systemic review of the pertinent literature. The mechanisms through which the different classes of glial cells become involved in the appearance of ND are poorly understood; however, evidence indicates that their role could be a critical factor in these pathologies' appearance, regulation and chronicity, these being largely determined by different types of cellular interactions and interaction with the microenvironment. This review shows that ND genetics regarding glial cells' cellular, molecular and genetic functioning represents a complex and understudied process; studying these factors could be a key step for ascertaining the origin of these pathologies, thereby leading to more effective therapies being developed.