Novel mannopyranoside esters as sterol 14α-demethylase inhibitors: Synthesis, PASS predication, molecular docking, and pharmacokinetic studies.

Direct unimolar one-step valeroylation of methyl α-d-mannopyranoside (MDM) furnished mainly 6-O-valeroate. However, similar reaction catalyzed by DMAP resulted 3,6-di-O-valeroate (21%) and 6-O-valeroate (47%) indicating reactivity sequence as 6-OH>3-OH>2-OH,4-OH. To get potential antimicrobial agents, 6-O-valeroate was converted into four 2,3,4-di-O-acyl esters, and 3,6-di-O-valeroate was converted into 2,4-di-O-acetate. Direct tetra-O-valeroylation of MDM gave a mixture of 2,3,4,6-tetra-O-valeroate and 2,3,6-tri-O-valeroate indicating that the C2-OH is more reactive than the equatorial C4-OH. The activity spectra analysis along with in vitro antimicrobial evaluation clearly indicated that these novel MDM esters had better antifungal activities over antibacterial agents. In this connection, molecular docking indicated that these MDM esters acted as competitive inhibitors of sterol 14α-demethylase (CYP51), an essential enzyme for clinical target to cure several infectious diseases. Furthermore, pharmacokinetic studies revealed that these MDM esters may be worth considering as potent candidates for oral and topical administration. Structure activity relationship (SAR) affirmed that saturated valeric chain (C5) in combination with caprylic (C8) chains was more promising CYP51 inhibitor over conventional antifungal antibiotics.

Mannose-anchored N,N,N-trimethyl chitosan nanoparticles for pulmonary administration of etofylline.

Drug delivery to lungs via pulmonary administration offers potential for the development of new drug delivery systems. Here we fabricated the etofylline (ETO) encapsulated mannose-anchored N,N,N-trimethyl chitosan nanoparticles (Mn-TMC NPs). The prominent characteristics like biocompatibility, controlled release, targeted delivery, high penetrability, enhanced physical stability, and scalability mark Mn-TMC NPs as a viable alternative to various nanoplatform technologies for effective drug delivery. Mannosylation of TMC NPs leads to the evolution of new drug delivery vehicle with gratifying characteristics, and potential benefits in efficient drug therapy. It is widely accepted that following pulmonary administration, the introduction of mannose to the surface of drug nanocarriers provide selective macrophage targeting via receptor-mediated endocytosis. The fabricated Mn-TMC NPs exhibited particle size of 223.3 nm, PDI 0.490, and ζ-potential -19.1 mV, drug-loading capacity 76.26 ± 1.2%, and encapsulation efficiency of 91.75 ± 0.88%. Sustained drug release, biodegradation studies, stability, safety, and aerodynamic behavior revealed the effectiveness of prepared nanoformulation for pulmonary administration. In addition, the in vivo pharmacokinetic studies in Wistar rat model revealed a significant improvement in therapeutic efficacy of ETO, illustrating mannosylation a promising approach for efficient therapy of airway diseases following pulmonary administration.

Hybrid (2D/3D) Dosimetry of Radiolabeled Gold Nanoparticles for Sentinel Lymph Node Detection in Patients with Breast Cancer.

Previously, we reported the preparation and preclinical studies of 99mTc-labeled gold nanoparticles-mannose (99mTc-AuNP-mannose) with potential for sentinel lymph node (SLN) detection by using nuclear medicine procedures. This study aimed to evaluate the biokinetics and hybrid (2D/3D) dosimetry of 99mTc-AuNP-mannose in five patients with breast cancer under a sentinel lymph node detection protocol. Anterior and posterior whole-body planar images (2D, at 0.5, 2, 6, and 24 h) and single-photon emission computed tomography (3D at 6.5 h)/computed tomography (SPECT/CT) images were acquired after 99mTc-AuNP-mannose administration (37 MBq). Through a hybrid quantification method, activity in tissues of interest at the different acquisition times was determined and integrated over time to obtain the total nuclear transformations (N), as well as the mean residence time, in each tissue. N values and the OLINDA code were used for estimating the internal radiation absorbed doses. Results demonstrated that 99mTc-AuNP-mannose successfully accumulates and remains up to 24 h in the sentinel lymph node without detectable migration to other lymph nodes and no side effects on patients. Negligible absorption of the radiolabeled nanoparticles into the circulatory system was observed, from which the radio-nanosystem is rapidly eliminated by kidneys. Hybrid (2D/3D) dosimetry evaluations showed equivalent doses to SLN, breast, and kidneys of 172.34, 5.32, and 0.08 mSv/37 MBq, respectively, with an effective dose of 2.05E - 03 mSv/MBq. The mean effective residence time in SLN was 0.92 h. This preliminary study indicates that the use of 99mTc-AuNP-mannose for successful SLN detection in patients is safe, producing an effective dose at the level recommended for diagnostic studies (<10 mSv).

Azido-galactose outperforms azido-mannose for metabolic labeling and targeting of hepatocellular carcinoma.

Metabolic glycoengineering of unnatural monosaccharides provides a facile method to label cancer cells with chemical tags for glycan imaging and cancer targeting. Multiple types of monosaccharides have been utilized for metabolic cell labeling. However, the comparison of different types of monosaccharides in labeling efficiency and selectivity has not been reported. In this study, we compared N-azidoacetylgalactosamine (GalAz) and N-azidoacetylmannosamine (ManAz) for metabolic labeling of HepG2 hepatocellular carcinoma in vitro and in vivo. GalAz showed higher labeling efficiency at low concentrations, and outperformed ManAz in metabolic labeling of HepG2 tumors in vivo. GalAz mediated labeling of HepG2 tumors with azido groups significantly improved the tumor accumulation of dibenzocyclooctyne (DBCO)-Cy5 and DBCO-doxorubicin conjugate via efficient Click chemistry. This study, for the first time, uncovered the distinct labeling efficiency and selectivity of different unnatural monosaccharides in liver cancers.

Mannosylated graphene oxide as macrophage-targeted delivery system for enhanced intracellular M.tuberculosis killing efficiency.

Tuberculosis (TB), caused by M.tuberculosis (Mtb), has become a top killer among infectious diseases. Enhancing the ability of anti-TB drugs to kill intracellular Mtb in host cells remains a big challenge. Here, an innovative nano-system was developed to increase drug delivery and Mtb-killing efficacy in Mtb-infected macrophages. We employed mannose surface decoration to develop mannosylated and PEGylated graphene oxide (GO-PEG-MAN). Such nano-platform exhibited increased uptake by macrophages via mannose receptor-mediated endocytosis in vitro. Interestingly, drug-loaded GO-PEG-MAN was preferentially up-taken by mannose receptor-expressing mucosal CD14+ macrophages isolated from Mtb-infected rhesus macaques than drug-loaded GO-PEG. Consistently, the drug concentration was also significantly higher in macrophages than that in T and B cells expressing no or low mannose receptor, implicating a useful macrophage/mannose receptor-targeted drug-delivery system relevant to the in vivo settings. Concurrently, rifampicin-loaded GO-PEG-MAN (Rif@GO-PEG-MAN) significantly increased rifampicin uptake, inducing long-lasting higher concentration of rifampicin in macrophages. Such innovative Rif@GO-PEG-MAN could readily get into the lysosomes of the Mtb host cells, where rifampicin underwent an accelerated release in acidic lysosomic condition, leading to explosive rifampicin release after cell entry for more effective killing of intracellular Mtb. Most importantly, Rif@GO-PEG-MAN-enhanced intracellular rifampicin delivery and pharmacokinetics significantly increased the efficacy of rifampicin-driven killing of intracellular BCG and Mtb bacilli in infected macrophages both in vitro and ex vivo. Such innovative nanocarrier approach may potentially enhance anti-TB drug efficacy and reduce drug side effects.

Effect of mannose targeting of hydroxyl PAMAM dendrimers on cellular and organ biodistribution in a neonatal brain injury model.

Neurotherapeutics for the treatment of central nervous system (CNS) disorders must overcome challenges relating to the blood-brain barrier (BBB), brain tissue penetration, and the targeting of specific cells. Neuroinflammation mediated by activated microglia is a major hallmark of several neurological disorders, making these cells a desirable therapeutic target. Building on the promise of hydroxyl-terminated generation four polyamidoamine (PAMAM) dendrimers (D4-OH) for penetrating the injured BBB and targeting activated glia, we explored if conjugation of targeting ligands would enhance and modify brain and organ uptake. Since mannose receptors [cluster of differentiation (CD) 206] are typically over-expressed on injured microglia, we conjugated mannose to the surface of multifunctional D4-OH using highly efficient, atom-economical, and orthogonal Cu(I)-catalyzed alkyne-azide cycloaddition (CuAAC) click chemistry and evaluated the effect of mannose conjugation on the specific cell uptake of targeted and non-targeted dendrimers both in vitro and in vivo. In vitro results indicate that the conjugation of mannose as a targeting ligand significantly changes the mechanism of dendrimer internalization, giving mannosylated dendrimer a preference for mannose receptor-mediated endocytosis as opposed to non-specific fluid phase endocytosis. We further investigated the brain uptake and biodistribution of targeted and non-targeted fluorescently labeled dendrimers in a maternal intrauterine inflammation-induced cerebral palsy (CP) rabbit model using quantification methods based on fluorescence spectroscopy and confocal microscopy. We found that the conjugation of mannose modified the distribution of D4-OH throughout the body in this neonatal rabbit CP model without lowering the amount of dendrimer delivered to injured glia in the brain, even though significantly higher glial uptake was not observed in this model. Mannose conjugation to the dendrimer modifies the dendrimer's interaction with cells, but does not minimize its inherent inflammation-targeting abilities.

Mannosylated Constructs as a Platform for Cell-Specific Delivery of Bioactive Agents.

Dictating the transport of drug carriers and augmenting the drug concentration at the desired anatomical site with high selectivity are worthwhile pursuits of current pharmaceutical research. Such approaches to drug targeting have been classified into passive and active strategies. As discussed in this article, active targeting promises greater selectivity because it exploits the incorporation of appropriate ligands, which are recognized by the target cells. Ligands, such as folate, peptides, transferrin, antibodies and their fragments, sugar, and sugar-mimetics, etc., with affinity to the molecules typical to or enriched in target tissues, have been investigated in this context. Mannose receptors (MRs) are abundantly expressed on a variety of cells, such as antigen-presenting cells, dendritic cells, and macrophages. Mannose receptors have lectin recognition domains that exhibit a high binding affinity for mannose. As a result, specific recognition of mannose-functionalized constructs has extensively been explored in the cell-specific targeting of drugs, vaccines, and other bioactive agents. This review outlines and discusses the key aspects of synthesis of mannosylated constructs, their mode of cellular uptake and application to targeted delivery of bioactive agents.

Novel PET Imaging of Atherosclerosis with 68Ga-Labeled NOTA-Neomannosylated Human Serum Albumin.

Activated macrophages take up 18F-FDG via glucose transporters, so this compound is useful for atherosclerosis imaging by PET. However, 18F-FDG application is limited for imaging of the heart and brain, in which glucose uptake is high, and in patients with aberrant glucose metabolism. The aims of this study were to confirm that mannosylated human serum albumin (MSA) specifically binds to the mannose receptor (MR) on macrophages and to test the feasibility of 68Ga-labeled NOTA-MSA for PET imaging of atherosclerotic plaques. METHODS: The peritoneal macrophages of C57/B6 mice were collected, incubated with rhodamine B isothiocyanate-MSA (10 µg/mL), and evaluated by confocal microscopy and flow cytometry. The same evaluations were performed after preincubation of the macrophages with anti-CD206 MR blocking antibodies. NOTA-MSA was synthesized by conjugating 2-(p-isothiocyanatobenzyl)-1,4,7-triazacyclononane-1,4,7-triacetic acid to MSA, followed by labeling with 68Ga. Rabbits with atherosclerotic aorta induced by a 3-mo cholesterol diet and chronic inflammation underwent consecutive PET/CT with 18F-FDG and 68Ga-NOTA-MSA at 2-d intervals. RESULTS: The binding of MSA to MR and its dose-dependent reduction by preincubation with anti-CD206 MR blocking antibody were confirmed. Rhodamine B isothiocyanate and fluorescein isothiocyanate fluorescence colocalized at the atherosclerotic plaque. The 68Ga-NOTA-MSA SUVs of the atherosclerotic aorta were significantly higher than those of the healthy arteries and inferior vena cava and were comparable to those obtained with 18F-FDG. CONCLUSION: These findings suggest that MR-specific 68Ga-NOTA-MSA is effective for detecting atherosclerosis in the aorta and is a promising radiopharmaceutical for imaging atherosclerosis because of the presence of M2 macrophages in atherosclerotic plaques.

Development and optimization of curcumin-loaded mannosylated chitosan nanoparticles using response surface methodology in the treatment of visceral leishmaniasis.

OBJECTIVE: The study aims at formulation and optimization of macrophage-targeted curcumin-loaded mannosylated chitosan nanoparticles (Cur-MCNPs) of curcumin (CUR) to improve its therapeutic potential in the treatment of visceral leishmaniasis (VL). METHODS: Response surface methodology (RSM) using central composite design was employed to study the effect of formulation factors on physicochemical-dependent characteristics. Chitosan was coupled with d-mannose, by reductive amination, to prepare a mannosylated chitosan, a conjugate polymer and a subsequent formulation of Cur-MCNPs. Optimized formulation prepared using RSM was evaluated for in vitro release kinetics at physiological pH 7.4 and endosomal macrophage pH 4.5; in vivo pharmacokinetic profile and targeting potential were evaluated by fluorescence microscopy. RESULTS: Optimized Cur-MCNPs exhibited spherical and smooth surface with a mean particle size of 215 nm, polydispersity index of 0.381, zeta potential of + 24.37 mV and % entrapment efficiency of 82.12%. The pharmacokinetic study of optimized Cur-MCNPs showed significant improvement in the value of mean resident time (39.38 h) compared to free CUR solution (0.30 h) (p < 0.05). In vivo uptake study indicated that endocytosis took place effectively within the macrophages of reticuloendothelial system. CONCLUSIONS: Thus, Cur-MCNPs could be considered as a promising delivery strategy towards active targeting of CUR to macrophages for the effective treatment of VL.

Effect of space length of mannose ligand on uptake of mannosylated liposome in RAW 264.7 cells: In vitro and in vivo studies.

The most widely used method for increasing uptake on macrophage is specific targeting for mannose receptor (MR) presented on macrophages. Efficiency of the uptake for MR is influenced by the space length and flexibility of mannose ligand in liposome (LP). We prepared mannosylated liposomes (M-EGn-LP-ICG) encapsulated indocyanine green (ICG) with mannose ligand of various ethylene glycol units (EG), LP-ICG, and mannosylated liposome (M-LP-ICG) incorporated with p-aminophenyl-α-d-mannopyranoside. We studied the effect of space length of the mannose ligand in vitro and in vivo with prepared liposomes. A space length of two ethylene glycol units at least was needed for uptake by macrophages and the uptake was increased as the space length increased up to EG4. We measured near-infrared (NIR) fluorescence intensity by ICG and the fluorescence value of cell-associated N-(4-nitrobenzo-2-oxa-1,3-diazole) (NBD) in liposome after cellular uptake. M-EG4-LP-ICG showed lower NIR fluorescence intensity but higher NBD fluorescence value than M-LP-ICG. The result of pre-treatment with d(+)-mannose as an inhibitor showed significant decreasing in uptake of mannosylated LP-ICG but no difference in LP-ICG. These were explained that mannosylated LP-ICG was taken up by macrophages through the MR and M-EG4-LP-ICG showed more specific uptake than M-LP-ICG. We obtained images as time passed in the NIR range after intravenous administration using a Balb/c mouse with inflammatory model. The results showed high uptake in liver at early time and rapid degradation of mannosylated LP-ICG. M-EG4-LP-ICG was more selectively taken up by macrophages than M-LP-ICG.

Comparative biological evaluation of two [99mTc(CO)3]-dextran pyrazolyl mannose conjugates developed for use in sentinel lymph node detection.

AIM: This work aims to develop receptor based alternatives to the conventional colloidal tracers in sentinel lymph node (SLN) detection. In this study, we report the detailed biological evaluation of two dextran pyrazolyl mannose derivatives towards this purpose. METHODS: The dextran pyrazolyl mannose derivatives (DAPM4 and DAPM8) were labeled with the [99mTc(CO)3(H2O)3]+ core. In vitro saturation binding studies for the ligands were performed in mannose receptor-bearing RAW 264.7 macrophage precursor cells. Localization and pharmacokinetics studies of the tracers were conducted in normal Wistar rats with different ligand concentrations using in vivo activity distribution and scintigraphic imaging techniques. RESULTS: The ligands were labeled with the [99mTc(CO)3)]+ core in high yield and radiochemical purity (>90%). DAPM4 and DAPM8 showed specific uptake in RAW 264.7 cells. In vivo localization studies showed concentration-dependent uptake and selective retention of the [99mTc]-labeled complexes of DAPM4 and DAPM8 in the sentinel node with highly favorable values of popliteal extraction [PE] (%PEDAPM4=92.94%,%PEDAPM8=91.80% at 180 min p.i.) and rapid clearance from the site of injection when administered at 50 µg/mL ligand concentration. CONCLUSION: [99mTc(CO)3]-complexes of DAPM4 and DAPM8 show good in vivo potential to undergo further testing as agents for SLN detection in the clinic and their biological efficacy varies depending upon the concentration of ligands used for the procedure.

Design and development of (99m)tc-'4+1'-labeled dextran-mannose derivatives as potential radiopharmaceuticals for sentinel lymph node detection.

The synthesis, labeling, and biological evaluation of a dextran derivative (DCM-30-iso) as potential radiopharmaceutical for sentinel lymph node imaging is presented. DCM-30-iso bears mannose as active moiety and isocyanide as ligand for technetium through the formation of a '4+1' Tc(III) mixed-ligand complex. A second derivative without mannose (DC-25-iso) was also prepared and evaluated as control. DCM-30-iso and DC-25-iso were synthesized from dextran in four steps (>50% overall yield) and characterized by spectroscopic methods. Labeling with (99m)Tc was achieved by reaction with 2,2',2''-nitrilotris(ethanethiol) and (99m)Tc-EDTA. Radiochemical purity was above 90% and was stable for at least 4 hours postlabeling at 37°C. The identity of the (99m)Tc complex was established through comparative HPLC studies using the well-characterized analogous Re-DC-25-iso complex. Biodistribution and imaging experiments of (99m)Tc-DCM-30-iso showed high uptake in the popliteal lymph node, which could be blocked with preinjection of mannose, and very low uptake in other nodes and organs. The nonmannosylated (99m)Tc-DC-25-iso derivative showed negligible uptake in all lymph nodes. The novel dextran-mannose derivative DCM-30-iso can be successfully labeled with (99m)Tc to give a well-characterized '4+1' complex with favorable biological properties as sentinel lymph node imaging agent.

Carbohydrate-conjugated porphyrin dimers: synthesis and photobiological evaluation for a potential application in one-photon and two-photon photodynamic therapy.

We report the synthesis of bioconjugated zinc porphyrin dimers 1a-e designed as photosensitizers for one-photon and two-photon excited photodynamic therapy. These macrocycles are substituted with carbohydrate units (glucose, mannose, lactose) in order to target tumor cells over-expressing lectin membrane receptors. Polarity, singlet oxygen production and in vitro photocytotoxicity are studied to determine their photodynamic therapy potentiality.

Glycodendritic structures: tools to interact with DC-SIGN

The key role of carbohydrates in many biological events has attracted the interest of the scientific community. This fact has demanded the access to new tools necessary to understand this role and the interaction of carbohydrates with their corresponding receptors, lectins. Glycodendrimers and glycodendritic structures in general, have demonstrated to be very efficient and interesting tools to intervene in those processes where carbohydrates participate. In this review, we discuss the different glycodendritic structures that have been used to interfere with DC-SIGN, a very attractive lectin involved in infection processes and in the regulation of the immune response.

O papel chave dos carboidratos em muitos eventos biológicos tem atraído interesse da comunidade científica. Este fato demonstrou o acesso de novas ferramentas para a compreensão da interação dos carboidratos com seus receptores correspondentes, lectinas. Glicodendrímeros e estruturas glicodendríticas, em geral, mostram-se como ferramentas muito eficientes e interessantes para intervir nos processos em que os carboidratos participam. Nesta revisão, discutimos diferentes estruturas glicodendríticas que têm sido úteis para interferir com DC-SIGN, uma lectina muito atraente envolvida em processos infecciosos e na regulação da resposta imune.

Macrophages targeting of amphotericin B through mannosylated multiwalled carbon nanotubes.

The objective of the present investigation was to assess the potential of polysaccharide (mannose) conjugated engineered multiwalled carbon nanotubes (MWCNTs) bearing Amphotericin B (AmB) formulation for site-specific delivery to macrophages. The mannosylated carbon nanotubes (CNTs) were synthesized and AmB was efficiently loaded using dialysis diffusion method. The synthesized mannosylated MWCNTs were characterized by various physicochemical and physiological parameters such as fourier transform infrared (FTIR) spectroscopy, scanning and transmission electron microscopy (SEM & TEM), drug loading and entrapment efficiency, in-vitro release kinetics, in-vivo study and toxicological investigation. AmB loaded mannosylated MWCNTs (AmBitubes) was found to be nanometric in size (500 nm) with tubular structure and good entrapment efficiency (75.46 ± 1.40%). In-vitro AmB from AmBitubes was found to be released in a controlled manner at pH 4, 7.4 and 10, with enhanced cell uptake and higher disposition in macrophage-rich organs, thereby indicating the site-specific drug delivery. The results suggest that AmBitubes could be employed as efficient nano-carrier for antileishmanial therapy.

FimH antagonists: structure-activity and structure-property relationships for biphenyl α-D-mannopyranosides.

Urinary tract infections (UTIs) are caused primarily by uropathogenic Escherichia coli (UPEC), which encode filamentous surface-adhesive organelles called type 1 pili. FimH is located at the tips of these pili. The initial attachment of UPEC to host cells is mediated by the interaction of the carbohydrate recognition domain (CRD) of FimH with oligomannosides on urothelial cells. Blocking these lectins with carbohydrates or analogues thereof prevents bacterial adhesion to host cells and therefore offers a potential therapeutic approach for prevention and/or treatment of UTIs. Although numerous FimH antagonists have been developed so far, few of them meet the requirement for clinical application due to poor pharmacokinetics. Additionally, the binding mode of an antagonist to the CRD of FimH can switch from an in-docking mode to an out-docking mode, depending on the structure of the antagonist. In this communication, biphenyl α-D-mannosides were modified to improve their binding affinity, to explore their binding mode, and to optimize their pharmacokinetic properties. The inhibitory potential of the FimH antagonists was measured in a cell-free competitive binding assay, a cell-based flow cytometry assay, and by isothermal titration calorimetry. Furthermore, pharmacokinetic properties such as log D, solubility, and membrane permeation were analyzed. As a result, a structure-activity and structure-property relationships were established for a series of biphenyl α-D-mannosides.

Transplacental supply of mannose and inositol in uncomplicated pregnancies using stable isotopes.

OBJECTIVE: The aim of this study was to determine relative contributions of transplacental flux vs. fetal production for inositol and mannose in normal term pregnancies. STUDY DESIGN: Seven term uncomplicated pregnancies undergoing cesarean section were infused with (13)C- and (2)H-labeled isotopes of glucose, inositol, and mannose until a steady state was achieved. Maternal and fetal concentrations of labeled and unlabeled glucose, mannose, and inositol were measured using gas chromatography/mass spectroscopy. The fetomaternal molar percentage excess ratio was calculated for each glucose, mannose, and inositol. RESULTS: The fetomaternal molar percentage excess ratio of mannose in the fetal artery (F(artery)/M) was 0.99 [97.5% confidence interval (CI), 0.91-1.07] and in the fetal vein (F(vein)/M), 1.02 (97.5% CI, 0.95-1.10). Both were not significantly different from 1.0, consistent with transplacental supply. The fetomaternal ratios for glucose were similar to mannose (fetal artery, 0.95; 97.5% CI, 0.84-1.15; and fetal vein, 0.96; 97.5% CI, 0.85-1.07). The fetomaternal ratio for inositol was significantly less than 1.0 (fetal artery, 0.08; 97.5% CI, 0.05-0.12; fetal vein, 0.12; 97.5% CI, 0.06-0.18), indicating little transplacental flux and significant fetal production. CONCLUSION: In normal term pregnancies, fetal mannose and glucose concentrations are dependent upon maternal transplacental supply. Fetal inositol is not dependent upon transplacental supply.

Investigations into an alternate approach to target mannose receptors on macrophages using 4-sulfated N-acetyl galactosamine more efficiently in comparison with mannose-decorated liposomes: an application in drug delivery.

In this study the potential of 2 different ligands, i.e., palmitoyl mannose (Man-Lip) and 4-SO(4)GalNAc (Sulf-Lip) to target resident macrophages was investigated after surface decoration of Amphotericin B (AmB) loaded liposomes. In the case of Sulf-Lip, the 4-SO(4)GalNAc was adsorbed through electrostatic interaction on cationic liposomes, which was confirmed by change in zeta potential from +48.2 ± 3.7 mV for Lip to +12.2 ± 1.3 mV for Sulf-Lip. The mean particle size of Sulf-Lip and Man-Lip was found to be 139.4 ± 7.4 nm and 147.4 ± 8.6 nm, respectively. Flow cytometric data reveal enhanced uptake of Sulf-Lip in both J774 and RAW cell lines in comparison with the uptake of Man-Lip. Intracellular localization studies indicate that the fluorescence intensity of Sulf-Lip was much higher in comparison with that of Man-Lip and Lip formulations. Sulf-Lip and Man-Lip showed significantly higher localization of AmB at all time points in comparison with Lip (P < 0.05) after intravenous (IV) administration. The studies provide evidence that 4-SO(4)GalNAc possesses a promising feature for targeting resident macrophages and its application in the conditions of leishmaniasis is in the offing. FROM THE CLINICAL EDITOR: This in vivo study compares two different ligands to deliver Amphotericin B l(AmB) loaded liposomes to resident macrophages. Targeted approaches showed significantly higher localization of AmB at all time points in comparison to non-targeted liposomes, and future applications in leishmaniasis are already under preparation.

Combining dose and injection volume for good performance of a specific radiopharmaceutical for sentinel node detection.

INTRODUCTION: The aim of this work was to quantify the effects of injection volume at different technetium-99m specific radiotracer doses on its lymphatic movement in animal model. PROCEDURES: Effects of injection volume (50, 100 µl) at different doses (0.05, 0.135, 0.22 nmol) on popliteal node (PN) detection were studied in rats. The radiotracer under study was (99m)Technetium-cysteine-mannose-dextran conjugate (30 kDa). RESULTS: At 0.05 nmol dose, higher PN uptake was observed at 50 µl injection volume (2.6 fold increase). Conversely, at 0.135 nmol dose, an increase of radiotracer retention in PN was achieved at 100 µl volume, 78% higher than 50 µl. However, at 0.22 nmol dose, the injection volume changes did not influence on the PN uptake. Considering as suitable radiotracer performance: high PN uptake and extraction, better combinations were 0.05 nmol/50 µl, 0.135 nmol/100 µl, 0.22/50 µl. CONCLUSION: Suitable performances could be reached by proper combinations of dose, injection volume and concentration for a specific radiotracer used in sentinel lymph node detection.

Dual cross-linked pulsatile beads for chronotherapy of asthma: development and evaluation.

In the present investigation, pulsatile release beads were prepared by ionic gelation technique. Theophylline dual-cross-linked beads were prepared by dropping dispersed phase of theophylline, Delonix regia gum (DRG), and sodium alginate into the dispersion phase of different concentration of calcium chloride solution followed by aluminium chloride solution. The formulated beads were further coated by Eudragit L & S 100 in the ratio 1:2 w/w in order to achieve desired lag time. In vitro release study showed lag time of 5­7 h before release of theophylline from the formulated beads, which were found to be intact for 6 h. Thus, formulated dual cross-linked beads when administered at bed time may release theophylline when needed most for chronotherapeutics of early morning asthmatic attacks in chronic patients. In vivo radio imaging study carried out in New Zealand white strain rabbit confirms the findings of in vitro results.