Current Pharmaceutical Biotechnology - Volume 16, Issue 10, 2015

Diabetes mellitus has been a threat to humans for many years. Amongst the different diabetes types, type 2 diabetes mellitus is the most common, and this is due to drastic changes in human lifestyle such as lack of exercise, stressful life and so on. There are a large number of conventional treatment methods available for type 2 diabetes mellitus. However, most of these methods are curative and are only applicable when the patient is highly symptomatic. Effective treatment strategies should be geared towards interfering with cellular and bio molecular mechanisms associated with the development and sustenance of the disease. In recent years, research into the medical potential of nanoparticles has been a major endeavor within the pharmaceutical industries. Nanoparticles display unique and tuneable biophysical characteristics which are determined by their shape and size. Nanoparticles have been used to manifest the properties of drugs, and as carriers for drug and vaccine delivery. Notwithstanding, there are further opportunities for nanoparticles to augment the treatment of a wide range of life threatening diseases that are yet to be explored. This review article seeks to highlight the application of potential nano-formulations in the treatment of type 2 diabetes mellitus. In addition, the activity of nanomedicine supplements in reversing insulin resistance is also discussed.

A large number of liposome-based non-viral gene and siRNA delivery systems include monovalent cholesteryl cytofectins with acyclic head groups in their formulations. Progress in their clinical development has, however, been hampered by relatively low transfection efficiencies. Structural differences between members of this class of cationic amphiphiles are located primarily in their linker, spacer and head group regions. This review examines the structural diversity encountered in each of these domains and seeks to identify those features linked to favourable transfection activity. Thus the ether linker, with its greater chemical and metabolic stability, is associated with higher transfection activity than ester, amide or carbamoyl tethers. While a medium length 6 atom spacer in the ether series is preferred over shorter spacers for enhanced activity, short (2 atom) to long (11 atom) spacers are effective in the more common carbamoyl series. For largely historic reasons, the dimethylamino head group has remained a popular cationic centre, but several studies have shown that the N-hydroxyethyl secondary amine functionality may be more effective in cytofectins. This observation has been attributed, in part, to the increased hydrophilicity of the head group and facilitated release of the nucleic acid cargo from liposomes in endosomal compartments. However, the hypothesis that the incorporation of each of these favourable chemical features into a single novel cytofectin may lead to superior transfection activity remains to be fully tested.

After several decades of immunization against hepatitis B virus, the question still remains whether a new vaccine could avoid the limitations of the current vaccine similar to those associated with its injectable form or ineffectiveness on chronic hepatitis B disease. A hypothesis to overcome first limitation is the development of an intranasal vaccine, self-administered, able to achieve not only systemic immunity, but also sIgA on the vaginal mucosa which would be a great advantage to prevent the sexually transmitted disease cases. Injectable hepatitis B vaccines that are already available in the market led to achieving protection mainly through a strong antibody-mediated response. For chronic hepatitis, a strong cellular immune response would also be required. The aim of this review is to give an overview of the work done in recent years, with the objective of developing a vaccine that can be administered by intranasal route. A discussion of the leading studies is presented, focusing not only on potential antigens, but also on promising adjuvants for the hepatitis B antigen. The results of the immune response generated with different formulations are summarized in tables. It is important to note that almost all studies claimed the induction of specific mucosal immune response (sIgA) and a balanced cellular and humoral Th1/Th2 or a Th1-type immune response. The further evaluation of these formulations, using a laboratory animal model of viral hepatitis B, would allow scientific community to conclude about the utility of these new adjuvants, particularly on a combined immunotherapy strategy for chronic hepatitis B.

Oxidative stress plays a key role in the pathogenesis of different serious chronic diseases such as cancer, diabetes, cardiovascular and neurodegenerative disorders, etc. Recent research has been focused on the beneficial role of dietary antioxidants against oxidative stress both under in vitro and in vivo conditions. Theobroma cacao L. (cacao tree) is an evergreen tree which is native to South America. It is a plant of great economic importance and its seeds are commonly used to produce cocoa powder and chocolate. In addition to its uses in food industry, cocoa is a rich source of polyphenolic antioxidants. There is a plethora of in vitro and in vivo studies that report cocoa antioxidant capacity. The protective activity of cocoa seems to be due to its phytochemical constituents, especially catechins. However, bioavailability of cocoa polyphenolic constituents following oral administration is very low (nanomolar concentrations). In the present paper, we critically reviewed the available literature on the antioxidant and free radical scavenging activities of cocoa and its polyphenolic constituents. In addition to these, we provide brief information about cultivation, phytochemistry, bioavailability and clinical impacts of cocoa.

For a long time, researchers have attempted to replace human plasmaderived immunoglobulin against HBV with recombinant HBV antibodies for therapeutic purposes, but failed to develop the products. One of the reasons may be lack of high throughput antibody screening tool. In this study, we screened an antibody library from immunized subjects by a powerful bacterial display technology. The capacity of the ScFv library was 10sup>9/sup>, 117 individual clones against HBV pre- S1 were initially selected and sequenced, the homology of these clones ranged from 59.7% -68.7%. Ten clones were randomly selected based on florescence intensity by FACS. The ScFv antibodies were expressed in E.coli/ and purified to examine their neutralization ability. First, we tested the ability of these clones to block the binding of the pre-S1 polypeptide to the HBV sensitive cells Chang liver cells and HepG2 cells, then, we examined the ability of these clones to inhibit the infection of the Change liver cells by HBV released from HepG2.2.15 cells by detection of viral DNA and hepatitis B virus e antigen (HBeAg) in the supernatant of Chang liver cells. Results showed that 4 (clone 3, 7, 9 and 31) out of the ten clones could significantly reduce the binding of pre-S1 polypeptide to Chang liver cells in a dose-dependent manner. Treatment with the same clones (clone 3, 7, 9 and 31) could dramatically reduce the contents of HBV DNA in the media of the infected Chang liver cells by 29.4, 7.89, 58.8, 76.9, respectively, and the amount of HBeAg by 60.2%, 32.6%, 66.1% and 68.1%, respectively. These results suggest that these clones can neutralize HBV infection and have the potential to become therapeutic antibodies against HBV infection to replace the human plasma-derived immunoglobulin

Interferon α2b (IFN α2b) is the first cytokine, which has been approved by FDA to treat chronic hepatitis B. However, it has no organ or tissue selectivity effect, and will be rapidly cleared out in the liver after the administration treatment. In our previous study, a novel liver-targeting fusion interferon (IFN-CSP) was constructed by recombining human IFN α2b with a CSP region I-plus peptide. The purpose of this study is to compare pharmacokinetics, tissue distribution, excretion of recombinant liver-targeting interferon IFN-CSP with IFN α2b following intramuscular administration in rats and estimate whether the fusion protein recombinant liver-targeting interferon has liver-targeting effect. Serum, tissue, urinary, fecal, and biliary concentrations of the drug were measured at various time points after administration using ELISA test. The pharmacokinetic character of IFN-CSP and IFNα2b was described using a non-compartmental model after a single intramuscular administration. Our results showed that there were no significant differences between these two drugs in pharmacokinetic and elimination. However, drug concentration of recombinant liver-targeting IFN was higher than IFN α2b in the liver after intramuscular administration in rats at different time points. It was increased in the spleen but not apparently, and decreased in the heart, lung and kidney. In conclusion, compared with traditional IFN α2b, the novel recombinant liver-targeting IFN will be more accumulated in the liver tissue. With this excellent property, IFN-CSP shows a great application prospect in clinical treatment, although further investigation is still needed.

The aim of the study was an assessment of the antioxidant, antifungal and cytotoxic potentials of L. betulinus/ and T. hirsuta/ mycelia extracts and the effect of selenium on these activities. Extracts of L. betulinus/ were twice as efficient in DPPH• scavenging as those of T. hirsuta/. The phenol content in Se-enriched L. betulinus/ extracts was higher than in non-enriched extracts, in contrast to the effect of Se-enrichment on T. hirsuta/ extracts, and a direct correlation between the amount and DPPH• scavenging effect was observed. Ethanol extracts exhibited fungistatic but not fungicidal activity against a range of micromycetes, and mycelium enrichment with selenium inhibited this effect. Although the extracts showed low cytotoxic activity against HeLa and LS174 cells, T. hirsuta/ extracts, especially those enriched with selenium, had better potential. L. betulinus/s extracts showed better antioxidant and antifungal activity than T. hirsuta extracts which were more active cytotoxic agents. The presence of selenium stimulated antioxidant and cytotoxic, and inhibited antifungal activity in L. betulinus/, while in T. hirsuta/ its effect was slight.

Single-walled carbon nanotubes (SWNT) have been widely explored as carriers for drug delivery because of their large surface area, high near-infrared absorption coefficient and facile transport through cellular membranes. In this study, Lysine (Lys) modified SWNT-liposomes conjugate loaded with doxorubicin (DOX) was designed to enhance the targeted drug delivery and antitumor effect. The conjugate (DOX-Lys/SWNT-Lip) was prepared with pH gradient methods, and the mean particle size and drug entrapment efficiency were 223±5.9 nm and 85.9 %, respectively. In vitro drug release study showed that DOX released much slowly from DOX-Lys/SWNT-Lip than from DOX solution, but faster than that of DOX-Lys/SWNT. DOX-Lys/SWNT-Lip could efficiently cross the cell membrane and afford higher anti-tumor efficacy on MCF-7 cells in vitro. For in vivo experiment, normal saline (N.S.), and DOX or DOX-Lys/SWNTLip were given to the S180 tumor bearing mice by i.v. administration, and followed by exposing the tumor site to nearinfrared laser (NIR) irradiation at 808 nm for 2 min. The relative tumor volumes in DOX-Lys/SWNT-Lip group and DOX group were obviously smaller than those of N.S. group. When combined with NIR laser irradiation, the suppression on tumor growth was much stronger. In conclusion, this study may provide potentially viable clinical strategies for tumor treatment with chemotherapy and photothermal therapy dual-mechanism.