Preparation and characterization of amphotericin B mannosylated liposomes for effective management of visceral leishmaniasis

Visceral leishmaniasis (VL) is a chronic debilitating disease prevalent in tropical and subtropical regions, caused by protozoan parasites of the genus Leishmania. Annually, it is approximated the occurrence of 0.2 to 0.4 million novel cases of the disease worldwide. The cast film method was used to prepared cationic and mannosylated liposomes. The surface of the Amphotericin B (Amp B)-bearing cationic multilamellar liposomes was covalently coupled with p-aminophenyl-α-D-mannoside using glutaraldehyde as a coupling agent, which was proved by agglutination of the vesicles with concanavalin A. The prepared liposomes were characterized for shape, size, % drug entrapment, vesicle count, zeta potential and in vitro drug release. Vesicle sizes of cationic and mannosylated liposomes were establish to be 2.71±0.12and 1.62±0.08μm, respectively. Zeta potential of cationic liposomes was higher (28.38 ± 0.3 mV), as compared to mannosylated liposomes (15.7 ± 0.8 mV). % drug release from cationic and mannose-coupled liposomes was established to be 45.7% and 41.9%, respectively, after 24 hrs. In the present work, cationic and mannosylated liposomes of Amp B were prepared, optimized and characterized for effectual organization of VL. Keywords: Mannosylated liposomes, Amphotericin B, Leishmaniasis, % drug release.

Quantitative Evaluation of Nucleic Acid Degradability of Copper Alloy Surfaces and Its Correlation to Antibacterial Activity

Copper (Cu) and its alloys have bactericidal activity known as “contact killing” with degradation of nucleic acids inside the bacteria, which is beneficial to inhibit horizontal gene transfer (HGF). In order to understand the nucleic acid degradability of Cu and its alloy surfaces, we developed a new in vitro method to quantitatively evaluate it by a swab method under a “dry” condition and compared it with that of commercially available antibacterial materials such as antibacterial stainless steel, pure silver, and antibacterial resins. As a result, only Cu and its alloys showed continuous degradation of nucleic acids for up to 6 h of contact time. The nucleic acid degradability levels of the Cu alloys and other antibacterial materials correlate to their antibacterial activities evaluated by a film method referring to JIS Z 2801:2012 for Gram-negative (Escherichia coli) and Gram-positive (Staphylococcus aureus) bacteria. Nucleic acid degradation by copper (I) and (II) chlorides was confirmed at the ranges over 10 mM and 1–20 mM, respectively, suggesting that the copper ion release may be responsible for the degradation of the nucleic acids on Cu and its alloy surfaces. In conclusion, the higher Cu content in the alloys gave higher nucleic acid degradability and higher antibacterial activities.

Photodynamic Therapy Targeting Macrophages Using IRDye700DX-Liposomes Decreases Experimental Arthritis Development

Macrophages play a crucial role in the initiation and progression of rheumatoid arthritis (RA). Liposomes can be used to deliver therapeutics to macrophages by exploiting their phagocytic ability. However, since macrophages serve as the immune system’s first responders, it is inadvisable to systemically deplete these cells. By loading the liposomes with the photosensitizer IRDye700DX, we have developed and tested a novel way to perform photodynamic therapy (PDT) on macrophages in inflamed joints. PEGylated liposomes were created using the film method and post-inserted with micelles containing IRDye700DX. For radiolabeling, a chelator was also incorporated. RAW 264.7 cells were incubated with liposomes with or without IRDye700DX and exposed to 689 nm light. Viability was determined using CellTiterGlo. Subsequently, biodistribution and PDT studies were performed on mice with collagen-induced arthritis (CIA). PDT using IRDye700DX-loaded liposomes efficiently induced cell death in vitro, whilst no cell death was observed using the control liposomes. Biodistribution of the two compounds in CIA mice was comparable with excellent correlation of the uptake with macroscopic and microscopic arthritis scores. Treatment with 700DX-loaded liposomes significantly delayed arthritis development. Here we have shown the proof-of-principle of performing PDT in arthritic joints using IRDye700DX-loaded liposomes, allowing locoregional treatment of arthritis.

The Influence of Polyvinyl Alcohol Solutions Concentration on the Rheological and Elastic and Strength Properties of Film Materials

During the study, solutions and film materials have been obtained with a concentration of polyvinyl alcohol in distilled water in the range of 1 ... 15 %. The rheological properties of the resulting solutions have been studied by rotational viscometer HAAKE VT 550 at a temperature of 20° C and 80° C. Film materials have been molded by cast film method. The elastic and strength properties of the film materials samples have been determined with a Gotech 7000M universal testing machine. It has been shown that with an increase in polyvinyl alcohol concentration, there has been a decrease in the elastic and strength properties. Samples of film material with 1% and 5% polyvinyl alcohol content completely dissolve in water in 10 and 20 minutes, respectively.

Film-Forming Spray of Water-Soluble Chitosan Containing Liposome-Coated Human Epidermal Growth Factor for Wound Healing

Human epidermal growth factor (hEGF) has been known to have excellent wound-healing activity. However, direct application to the wound area can lead to low hEGF bioavailability due to protease enzymes or endocytosis. The use of liposomes as coatings and carriers can protect hEGF from degradation by enzymes, chemical reactions, and immune reactions. Sustained release using a matrix polymer can also keep the levels of hEGF in line with the treatment. Therefore, this study aimed to develop a film-forming spray of water-soluble chitosan (FFSWSC) containing hEGF-liposomes as a potential wound dressing. The hEGF-liposomes were prepared using the hydration film method, and the preparation of the FFSWSC was achieved by the ionic gelation method. The hydration film method produced hEGF-liposomes that were round and spread with a Z-average of 219.3 nm and encapsulation efficiency of 99.87%, whereas the film-forming solution, which provided good sprayability, had a formula containing 2% WSC and 3% propylene glycol with a viscosity, spray angle, droplet size, spray weight, and occlusion factor of 21.94 ± 0.05 mPa.s, 73.03 ± 1.28°, 54.25 ± 13.33 µm, 0.14 ± 0.00 g, and 14.57 ± 3.41%, respectively. The pH, viscosity, and particle size of the FFSWSC containing hEGF-liposomes were stable during storage for a month in a climatic chamber (40 ± 2 °C, RH 75 ± 5%). A wound healing activity test on mice revealed that hEGF-liposomes in FFSWSC accelerated wound closure significantly, with a complete wound closure on day 6. Based on the findings, we concluded that FFSWSC containing hEGF-liposomes has the potential to be used as a wound dressing.

Pre-Lubricated Polypropylene Injector for Breast Implant Delivery

Breast augmentation is a common aesthetic surgery, and there are two major surgical methods for breast implant delivery: the finger method and the plastic film method. There are advantages and disadvantages for each method, and we have developed a pre-lubricated polypropylene (PP) injector that might be the most suitable device for delivering breast implants. By covering the interior surface of the injector with the hydrophilic coating, the friction coefficient was significantly reduced when sliding a silicone sled against the pre-lubricated PP injector. In order to confirm the pre-lubricated PP injector would not damage the breast implant, fatigue testing was performed and the result showed the injector did not cause rupture or microleakage of the breast implant. In addition, the cell viability result demonstrated the pre-lubricated PP injector was biocompatible. In addition, the pre-lubricated PP injector provides a small incision site and stability during breast implant delivery. Our results provided evidence that the pre-lubricated PP injector is a smooth and safe method for breast implant delivery.

Interactions of primaquine and chloroquine with PEGylated phosphatidylcholine liposomes

This study aimed to analyze the interaction of primaquine (PQ), chloroquine (CQ), and liposomes to support the design of optimal liposomal delivery for hepatic stage malaria infectious disease. The liposomes were composed of hydrogenated soybean phosphatidylcholine, cholesterol, and distearoyl-sn-glycero-3-phosphoethanolamine-N-(methoxy[polyethyleneglycol]-2000), prepared by thin film method, then evaluated for physicochemical and spectrospic characteristics. The calcein release was further evaluated to determine the effect of drug co-loading on liposomal membrane integrity. The results showed that loading PQ and CQ into liposomes produced changes in the infrared spectra of the diester phosphate and carbonyl ester located in the polar part of the phospholipid, in addition to the alkyl group (CH2) in the nonpolar portion. Moreover, the thermogram revealed the loss of the endothermic peak of liposomes dually loaded with PQ and CQ at 186.6 °C, which is identical to that of the phospholipid. However, no crystallinity changes were detected through powder X-ray diffraction analysis. Moreover, PQ, with either single or dual loading, produced the higher calcein release profiles from the liposomes than that of CQ. The dual loading of PQ and CQ tends to interact with the polar head group of the phosphatidylcholine bilayer membrane resulted in an increase in water permeability of the liposomes.