A Novel Neuroimaging Phenotype in the X-Linked Intellectual Disability with a Missense Mutation of CNKSR2 Gene.

Background: Mental retardation, X-linked, syndromic, Houge type (MRXSHG) is a form of mental retardation characterized by intellectual disability, speech and language impairments, and early-onset seizures. It has been recently recorded in Online Mendelian Inheritance in Man (OMIM), and only 10 cases have been reported in the literature so far. Objective: To highlight the novel neuroimaging findings in the pediatric X-linked intellectual disability with a missense mutation of connector enhancer of kinase suppressor of RAS2 (CNKSR2) gene. Material and Methods: We present a case of intellectual disability, refractory epilepsy, speech and language delay with subtle dysmorphism, and behavioral issues in an 11-year-old boy with novel neuroimaging findings in a CNKSR2 gene with missense mutation. Results: Brain MRI revealed involvement of the basal ganglia, predominantly the neostriatum, and along with the subependymal aspects with focal cavitations involving, especially the bilateral caudate heads. There was relative sparing of the globus pallidi and posterior putamina bilaterally. Whole-exome sequencing identified a hemizygous missense pathogenic variant in the CNKSR2 gene. The mother was found to be an asymptomatic carrier. Conclusion: This case report highlights the rare missense mutation in the CNKSR2 gene and abnormal neuroimaging findings, which further provide information about the phenotypic characteristics of X-linked syndromic intellectual disability.

Targeting luteinizing hormone-releasing hormone: A potential therapeutics to treat gynecological and other cancers.

Cancer is a prime healthcare problem that is significantly responsible for universal mortality. Despite distinguished advancements in medical field, chemotherapy is still the mainstay for the treatment of cancers. During chemotherapy, approximately 90% of the administered dose goes to normal tissues, with mere 2-5% precisely reaching the cancerous tissues. Subsequently, the resultant side effects and associated complications lead to dose reduction or even discontinuance of the therapy. Tumor directed therapy therefore, represents a fascinating approach to augment the therapeutic potential of anticancer bioactives as well as overcomes its side effects. The selective overexpression of LHRH receptors on human tumors compared to normal tissues makes them a suitable marker for diagnostics, molecular probes and targeted therapeutics. These understanding enabled the rational to conjugate LHRH with various cytotoxic drugs (doxorubicin, DOX; camptothecin etc.), cytotoxic genes [small interfering RNA (siRNA), micro RNA (miRNA)], as well as therapeutic nanocarriers (nanoparticles, liposomes or dendrimers) to facilitate their tumor specific delivery. LHRH conjugation enhances their delivery via LHRH receptor mediated endocytosis. Numerous cytotoxic analogs of LHRH were developed over the past two decades to target various types of cancers. The potency of LHRH compound were reported to be as high as 5,00-10,00 folds compared to parent molecules. The objective of this review article is to discuss reports on various LHRH analogs with special emphasis on their prospective application in the medical field. The article also focuses on the attributes that must be taken into account while designing a LHRH therapeutics with special account to the biochemistry and applications of these conjugates. The record on various cytotoxic analogs of LHRH are also discussed. It is anticipated that the knowledge of therapeutic and toxicological aspects of LHRH compounds will facilitate the development of a more systematic approach to the targeted delivery of cytotoxic agents using peptides.

Experimental Models for Evaluation of Nanoparticles in Cancer Therapy.

Nanoparticles (NPs), the submicron-sized colloidal particles, have recently generated enormous interest among biomedical scientists, particularly in cancer therapy. A number of models are being used for exploring NPs safety and efficacy. Recently, cancer cell lines have explored as prominent experimental models for evaluating pharmacokinetic parameters, cell viability, cytotoxicity and drug efficacy in tumor cells. This review aims at thorough compilation of various cancer cell lines and in vivo models for evaluation of efficacy of NPs on one platform. This will provide a basis to explore and improvise pre-clinical models as a prelude to successful cancer research.

Significance of Various Experimental Models and Assay Techniques in Cancer Diagnosis.

The experimental models are of vital significance to provide information regarding biological as well as genetic factors that control the phenotypic characteristics of the disease and serve as the foundation for the development of rational intervention stratagem. This review highlights the importance of experimental models in the field of cancer management. The process of pathogenesis in cancer progression, invasion and metastasis can be successfully explained by employing clinically relevant laboratory models of the disease. Cancer cell lines have been used extensively to monitor the process of cancer pathogenesis process by controlling growth regulation and chemo-sensitivity for the evaluation of novel therapeutics in both in vitro and xenograft models. The experimental models have been used for the elaboration of diagnostic or therapeutic protocols, and thus employed in preclinical studies of bioactive agents relevant for cancer prevention. The outcome of this review should provide useful information in understanding and selection of various models in accordance with the stage of cancer.

Transferrin functionalized chitosan-PEG nanoparticles for targeted delivery of paclitaxel to cancer cells.

The present investigation was aimed to utilize the stealth property of polyethylene glycol (PEG) modified chitosan nanoparticles (NPs) and active targeting function of transferrin (Tf) by transferrin receptor-mediated endocytosis to promote drug delivery to cancer cells. Paclitaxel (PTX) loaded nanoparticles (PTX-NP) were prepared by solvent evaporation method; PEGylation was carried out by coupling amine group present on the surface of NPs with hydroxyl group present on the PEG (NP-PEG). Tf conjugation was carried out by coupling carboxylic group present on the surface of ligand and hydroxyl group present on the PEG (NP-PEG-Tf). The uptake of NP-PEG-Tf into cancer cells was found to be higher as compared to non-targeted NPs. Compared with free PTX, PTX-NPs and PTX-NPs-PEG, the PTX-NPs-PEG-Tf demonstrated higher cytotoxicity to human Non-Small Cell Lung cancer cell lines (HOP-62), higher intracellular uptake especially in nuclei and lower hemolytic toxicity. Tf conjugated NPs showed increased retention time in the lungs as well as in blood. These findings indicate that Tf conjugated PEGylated nanoparticles are promising nanoconstructs for the delivery of anti-cancer drugs to cancer cells.

Ligand anchored poly(propyleneimine) dendrimers for brain targeting: Comparative in vitro and in vivo assessment.

The present investigation was aimed at developing various ligands-anchored dendrimers and comparing their brain targeting potential at one platform. Sialic acid (S), glucosamine (G) and concanavalin A (C) anchored poly(propyleneimine) (PPI) dendritic nanoconjugates were developed and evaluated for delivery of anti-cancer drug, paclitaxel (PTX) to the brain. MTT assay on U373MG human astrocytoma cells indicated IC50 values of 0.40, 0.65, 0.95, 2.00 and 3.50µM for PTX loaded SPPI, GPPI, CPPI, PPI formulations, and free PTX, respectively. The invivo pharmacokinetics and biodistribution studies in rats showed significantly higher accumulation of PTX in brain as compared to free PTX. The order of targeting potential of various ligands under investigation was found as sialic acid>glucosamine>concanavalin A. Thus, it can be concluded that sialic acid, glucosamine and Con A can be used as potential ligands to append PPI dendrimers for enhanced delivery of anticancer drugs to the brain for higher therapeutic outcome.

Pharmaceutical and biomedical applications of quantum dots.

Quantum dots (QDs) have captured the fascination and attention of scientists due to their simultaneous targeting and imaging potential in drug delivery, in pharmaceutical and biomedical applications. In the present study, we have exhaustively reviewed various aspects of QDs, highlighting their pharmaceutical and biomedical applications, pharmacology, interactions, and toxicological manifestations. The eventual use of QDs is to dramatically improve clinical diagnostic tests for early detection of cancer. In recent years, QDs were introduced to cell biology as an alternative fluorescent probe.

Eudragit-coated dextran microspheres of 5-fluorouracil for site-specific delivery to colon.

Objective of the present investigation was to prepare and evaluate the potential of enteric coated dextran microspheres for colon targeting of 5-fluorouracil (5-FU). Dextran microspheres were prepared by emulsification-crosslinking method and the formulation variables studied included different molecular weights of dextran, drug:polymer ratio, volume of crosslinking agent, stirring speed and time. Enteric coating (Eudragit S-100) of dextran microspheres was performed by oil-in-oil solvent evaporation method using different coat:core ratios (4:1 or 8:1). Uncoated and coated dextran microspheres were characterized by particle size, surface morphology, entrapment efficiency, DSC, in vitro drug release in the presence of dextranase and 2% rat cecal contents. The release study of 5-FU from coated dextran microspheres was pH dependent. No release was observed at acidic pH; however, the drug was released quickly where Eudragit starts solublizing there was continuous release of drug from the microspheres. Organ distribution study was suggested that coated dextran microspheres retard the release of drug in gastric and intestinal pH environment and released of drug from microspheres in colon due to the degradation of dextran by colonic enzymes.

Glycyrrhizin Conjugated Dendrimer and Multi-Walled Carbon Nanotubes for Liver Specific Delivery of Doxorubicin.

The purpose of the present investigation was to investigate the drug targeting potential of glycyrrhizin (GL) conjugated dendrimers (GL-PPI) and multi walled carbon nanotubes (GL-MWCNTs) towards liver targeting of a model anti-cancer agent, doxorubicin (DOX). The synthesis was confirmed by FTIR, 1H-NMR and morphology analysis. Higher DOX loading was observed in case of GL-PPI-DOX and GL-MWCNT-DOX (43.02 ± 0.64% and 87.26 0.57%, respectively) than parent nanocarriers. GL attachment considerably reduced the haemolytic toxicity of DOX by 12.38 ± 1.05 and 7.30 ± 0.63% by GL-PPI-DOX and GL-MWCNT-DOX, respectively. MTT cytotoxicity studies, flow cytometry and cell morphology assessment was done in HepG2 cell. The IC50 of DOX was reduced from 4.19±0.05 µM to 2.0±0.01 and 2.7±0.03 µM, respectively by GL-PPI-DOX and GL-MWCNT-DOX, respectively. Flow cytometry and phase contrast microscopy confirmed GL conjugated formulations to be significantly dragging higher cancer cell number of cells in early apoptosis as well as in early apoptotic phase.

Nanotechnology in Drug Delivery: Safety and Toxicity Issues.

Nanotoxicology deals with the new perception regarding nanotechnology i.e. risk and hazards associated with nanoscale materials. Although, nanotechnology is playing significant role in modern advancements from cell phones to medicines, yet it is necessary to consider their negative part as well that could be dangerous if not given proper attention. It is not certain that nanotechnology will essentially exert toxic effects since at present only few reports are available on their toxic effects and most of them are controversial. In this review we have summarized the advances in nanotechnology, their applications and, most importantly their safety issues that are often overlooked. However combined efforts are advocated to develop promising regulatory and ethical guidelines to control production, use and disposal of nanomaterials that will be safe to human health, environment and other living organisms.

Synthesis and characterization of dendro-PLGA nanoconjugate for protein stabilization.

The present investigation was aimed to develop the dendro-PLGA nanoconjugate (DPNC) for protection of insulin from degradation as well as its sustained release from nano-formulation. DPNC formulation was synthesized by 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride (EDC) coupling reaction and therapeutic efficacy of encapsulated protein (insulin) was measured by Sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE), Fourier transform infrared spectroscopy (FTIR) and circular dichorism (CD) spectroscopy. We have also demonstrated the ability of DPNC formulation to prevent the native conformation of insulin within the system by comparing the amount of free protein with the protein extracted from this system. Stability study further revealed that as compared to free protein, DPNC formulation was more efficient to stabilize the protein. Additionally, in vivo data of protein loaded system in rats showed that DPNC formulation can able to maintain the native structure of insulin and hence retain therapeutic efficacy of protein. The novel dendro-PLGA nanoconjugate not only stabilize the insulin but also work as sustained release reservoir for insulin which reduces the frequency of dosage and side effect associate with denatured protein.

Enteric-coated epichlorohydrin crosslinked dextran microspheres for site-specific delivery to colon.

Enteric-coated epichlorohydrin crosslinked dextran microspheres containing 5-Fluorouracil (5-FU) for colon drug delivery was prepared by emulsification-crosslinking method. The formulation variables studied includes different molecular weights of dextran, volume of crosslinking agent, stirring speed, time and temperature. Dextran microspheres showed mean entrapment efficiencies ranging between 77 and 87% and mean particle size ranging between 10 and 25 µm. About 90% of drug was released from uncoated dextran microspheres within 8 h, suggesting the fast release and indicated the drug loaded in uncoated microspheres, released before they reached colon. Enteric coating (Eudragit-S-100 and Eudragit-L-100) of dextran microspheres was performed by oil-in-oil solvent evaporation method. The release study of 5-FU from coated dextran microspheres was complete retardation in simulated gastric fluid (pH 1.2) and once the coating layer of enteric polymer was dissolved at higher pH (7.4 and 6.8), a controlled release of the drug from the microspheres was observed. Further, the release of drug was found to be higher in the presence of dextranase and rat caecal contents, indicating the susceptibility of dextran microspheres to colonic enzymes. Organ distribution and pharmacokinetic study in albino rats was performed to establish the targeting potential of optimized formulation in the colon.

One platform comparison of solubilization potential of dendrimer with some solubilizing agents.

OBJECTIVE: To compare various solubilizing agents for their solubilizing propensity as well as effect of pH, concentration and time on solubility of a highly hydrophobic drug. MATERIALS AND METHODS: Dendrimers were synthesized by divergent method. Solubilization studies were carried out at different pH, concentration and time using Paclitaxel (PTX) as model drug. Hemolytic toxicity study was also performed. RESULTS: The solubility of PTX was increased with increasing concentration of solubilizing agents and the order of solubility enhancement effect of different solubilizing agents was found to be in the following order: fifth generation (5.0 G) poly(propylene imine) (PPI) dendrimers > ß-CD > Tween 80 > polyethylene glycol 6000. The solubility of PTX was found to be highest at pH 5.0 followed by pH 7.4 than pH 9.2. The result of hemolytic toxicity studies displayed that when these solubilizing agents are given in combination with PTX, the toxicity was found to be reduced as compare to plain drug. CONCLUSIONS: The solubility of PTX was found to be significantly higher in the presence of 5.0 G PPI dendrimers as compared to the other solubilizing agents. It is also concluded that 5.0 G PPI dendrimers not only enhanced the solubility of PTX many folds but also reduced the toxicity of PTX.

The development, characterization and in vivo anti-ovarian cancer activity of poly(propylene imine) (PPI)-antibody conjugates containing encapsulated paclitaxel.

Mesothelin, protein is frequently expressed in ovarian cancers. However, a full understanding of the biological functions of mesothelin is lacking. Here, we investigate the drug targeting potential of antibody conjugated modified half-generation poly (propylene imine) dendrimers i.e. immunodendrimers toward ovarian cancer with a model anti-cancer agent, paclitaxel (PTX). The synthesized plain 4.5G dendrimers as well as immunodendrimers were characterized by FT-IR, (1)H-NMR, TEM, and flow cytometry. Immunodendrimers exhibited considerably reduced hemolytic-, hepato- and nephrotoxicity. MTT cytotoxicity, flow cytometry and cell morphology studies were conducted in OVACAR-3 and A-431 cell. We demonstrate that PTX loaded immunodendrimers reduced the tumor volume significantly. The biodistribution studies further confirmed the targeting efficiency and higher biodistribution of immunodendrimers into the mesothelin protein expressing ovarian cancer cells. The results concluded that the developed immunodendrimers have potential to deliver significantly higher amount of the bioactive and have improved therapeutic outcome.

Generation dependent safety and efficacy of folic acid conjugated dendrimer based anticancer drug formulations.

PURPOSE: Folate conjugated poly(propyleneimine) (PPI) dendrimer (FPPI) mediated anticancer therapy is being extensively discovered throughout the world. The present investigation was aimed at exploring the targeting potential of Melphalan loaded FPPI of different generations (MP-FPPI) for effective management of cancer. METHODS: The MP-FPPI formulations were compared for drug entrapment efficiency, in vitro release profile, toxicology, folate receptor blockage assay, cell uptake assay, stability studies, and in vivo studies. RESULTS: Upon increasing the dendrimer generation from fourth to fifth, the drug delivery parameters improved negligibly except the toxicological profile that improved exponentially. MTT assay in case of MCF-7 cells depicted the IC 50 values of 8 ± 0.15, 0.9 ± 0.02, 0.2 ± 0.01 and 10 ± 0.17 µM, respectively in case of MP-FPPI3, MP-FPPI4, MP-FPPI5, and free Melphalan suggesting folate based targeting to be the efficacious approach to kill cancer cells. The median survival time for tumor bearing mice treated with MP-FPPI3, MP-FPPI4, MP-FPPI5 and free drug was found to be 23, 59, 62 and 26 days, respectively. CONCLUSIONS: The study concludes fourth generation PPI dendrimer to be superior carrier for folate based tumor targeting compared to third and fifth generation based formulations. This work is expected to provide a significant clue in the selection of "dendrimer generation" for folate mediated cancer targeting therapy.

siRNA nanotherapeutics: a Trojan horse approach against HIV.

The concept of RNA interference (RNAi) is gaining popularity for the better management of various diseases, including HIV. Currently, the successful biomedical utilization of siRNA therapeutics is hampered, both in vivo and in vitro, mainly by the inherent inability of naked siRNA to cross the cell membrane. RNAi can potentially improve the weakness of current highly active antiretroviral therapy (HAART) by diminishing the chances of the appearance of antiHIV-resistant strains. Here, we discuss the nanocarrier-mediated delivery of siRNA delivery as well as highlighted the scope of siRNA-mediated gene-silencing technology for improved HIV treatment.

Generation dependent cancer targeting potential of poly(propyleneimine) dendrimer.

Dendrimer-mediated delivery of bioactive is a successful and widely explored concept. This paper desribes comparative data pertaining to generation dependent cancer targeting propensity of Poly(propyleneimine) (PPI) dendrimers. This debut report reportsthe drug targeting and antciancer potential of different dendrimer generations. PPI dendrimers of different generations (3.0G, 4.0G and 5.0G) were synthesized and loaded with Melphalan. Results from loading, hemolysis, hematologic, cytotoxicty and flow cytometry assay depicted that as the generation of dendrimer increased from fourth to fifth, the only parameter i.e. toxicty is increased exponentionally. However, others parameters, i.e. loading, sustained release behavior, and targeting efficacy increased negligibly. Kaplan-Meier survival curves clearly depicted comparable therapeutic potential of PPI4M with PPI5M. In vivo investigations in Balb/c mice again favored 4.0G PPI dendrimer to be preferable nanocarrier for anticancer drug delivery owing to analogous anticancer potential. The outcomes of the investigation evidently projects 4.0G PPI dendrimer over 3.0G and 5.0G dendrimer in respect of its drug delivery benefit as well as superior biocompatibility. Thus, much against the common belief, 4.0G PPI dendrimers may be considered to be optimum in respect of drug delivery precluding the use of much more toxic 5.0G PPI dendrimer, which offers no benefit over 4.0G.

Dendronized nanoconjugates of lysine and folate for treatment of cancer.

Poly-L-lysine (PLL) dendrimers are currently being investigated as antiangiogenic agent for therapy of cancer. In this study, we report folate conjugated poly-l-lysine dendrimers (FPLL) as an efficient carrier for model anticancer drug, doxorubicin hydrochloride (Dox); for pH sensitive drug release, selective targeting to cancer cells, anticancer activity and antiangiogenic activity. This nanoconjugate of Dox showed initial rapid in vitro release followed by gradual slow release, and the drug release was found to be pH sensitive with greater release at acidic pH. In the CAM assay and tubule formation assay with HUVEC, Dox-FPLL formulation showed the significant antiangiogenic activity confirming that activity of PLL was not compromised by the presence of Dox and folic acid. The ex vivo investigations with human breast cancer cell lines MCF-7 showed enhanced cytotoxicity of Dox-FPLL with significantly enhanced intracellular uptake (p<0.001). The in vivo therapeutic potential of nanoconjugate was determined in MCF-7 breast cancer xenograft model in tumor-bearing mice. Dox-FPLL increased the concentration of Dox in tumor by 121.5-fold after 24 h in comparison with free Dox formulation. The folate conjugated dendrimeric Dox showed superior anti-tumor activity in tumor xenograft model with significantly prolonged survival determined by Kaplan Meier survival analysis (p<0.001).