Liposomes for enhanced cytotoxic activity of bleomycin

Olive oil and flaxseed oil incorporating niosomes for enhanced in vivo anti-diabetic efficacy of canagliflozin

BACKGROUND

Canagliflozin (CFZ) is broadly implicated for the management of type 2 diabetes mellitus. Unfortunately, it has low oral bioavailability due to poor solubility behavior and restricted membrane permeability.

OBJECTIVE

The current work focuses on development of CFZ encapsulated niosomes for enhanced oral anti-diabetic efficacy.

METHODOLOGY

Niosomes comprising Span 60 and cholesterol were formulated both in absence and presence of olive oil or flaxseed oil. These were evaluated in vitro for average vesicular size, structural morphology, CFZ entrapment efficiency, and drug release. Additionally, the oral hypoglycemic effect of CFZ encapsulated niosomes was explored in diabetic rats.

RESULTS

The fabricated niosomes were negatively charged spherical vesicles with a size range of 103.0-141.7 nm. These entrapped CFZ with efficiency ranging from 92.3% to 96.0%. Drug release investigations reflected that incorporating CFZ into niosomes significantly sustained drug release compared to the aqueous drug dispersion. Oral administration of niosomal formulations significantly enhanced the oral antidiabetic effect of CFZ. Comparing the tested niosomes, similar efficiency was shown eliminating the effect of composition.

CONCLUSION

The enhanced oral bioavailability of niosomes' encapsulated drugs is related to niosomal vesicular structure which allows intact niosomes absorption. The study presented niosomes as promising carriers for improved oral anti-diabetic activity of CFZ.

Bleomycin loaded exosomes enhanced antitumor therapeutic efficacy and reduced toxicity

BACKGROUND

Bleomycin (BLM) is a chemotherapeutic agent with potent antitumor activity against the tumor. However, lung fibrosis is the main drawback that limits BLM use. Tumor targeted, safe, efficient and natural delivery of BLM is important to increase the effectiveness and reduce the toxic side effects. Although tumor derived Exosomes (Exo), provide a potential vehicle for in vivo drug delivery due to their cell tropism. This study primarily focuses on generating a natural delivery platform for Exo loaded with BLM and testing its therapeutic efficacy against cancer.

METHODS

Exosomes were isolated from cancer cells and incubated with BLM. Exo were characterized by transmission electron microscopy, western blot analysis and nanoparticle tracking analysis. We performed in vitro and in vivo analyses to evaluate the effect of Exo-BLM.

RESULTS

Exosomes loaded with BLM are highly cancer targeting and cause the cytotoxicity of tumor cells by ROS. The fluorescence images showed that Exo-BLM accumulated in cancer cells. The results revealed that Exo-BLM induces tumor cell apoptosis by the caspase pathway. In vivo, the treatment of Exo-BLM showed targeted ability and enhanced the antitumor activity.

CONCLUSION

This study provides an avenue for specific BLM therapeutics with minimal side effects.

Permeation enhancers loaded bilosomes for improved intestinal absorption and cytotoxic activity of doxorubicin

The clinical utility of doxorubicin is compromised due to dose related toxic side effects and limited oral bioavailability with no oral formulation being marketed. Enhancement of intestinal absorption and magnification of cytotoxicity can overcome these limitations. Accordingly, the objective was to probe penetration enhancers, bilosomes and their combinations for enhanced intestinal absorption and improved cytotoxicity of doxorubicin. Piperine and dipyridamole were tested as enhancers alone or encapsulated in bilosomes comprising Span60, cholesterol and bile salts. Bilosomes were nanosized spherical vesicles with negative zeta potential and were able to entrap doxorubicin with efficiency ranging from 45.3 % to 53 %. Intestinal absorption studies utilized in-situ rabbit intestinal perfusion which revealed site dependent doxorubicin absorption correlating with regional distribution of efflux transporters. Co-perfusion with the enhancer increased intestinal absorption with further augmentation after bilosomal encapsulation. The latter increased the % fraction absorbed by 4.5-6 and 1.8-2.5-fold from jejuno-ileum and colon, respectively, depending on bilosomes composition. Additionally, doxorubicin cytotoxicity against breast cancer cells (MCF-7) was significantly improved after bilosomal encapsulation and the recorded doxorubicin IC₅₀ value was reduced from 13.3 μM to 0.1 μM for the best formulation. The study introduced bilosomes encapsulating absorption enhancers as promising carriers for enhanced cytotoxicity and oral absorption of doxorubicin.

Bilosomes as Nanoplatform for Oral Delivery and Modulated In Vivo Antimicrobial Activity of Lycopene

Owing to the disseminating resistance among pathogenic bacteria, especially Klebsiella pneumoniae, there is a high need for alternate compounds with antibacterial activity. Herein, lycopene was isolated from Lycopersicon esculentum L. Molecular docking approach was employed to explore lycopene binding affinity to selected vital proteins of K. pneumoniae with the binding mechanisms being investigated. This proposed a promising antibacterial activity of lycopene. However, the pharmacological use of lycopene is hampered by its poor solubility and limited oral bioavailability. Accordingly, bilosomes were fabricated for oral lycopene delivery. The computed entrapment efficiency, mean vesicular size, and zeta potential values for the optimized formulation were 93.2 ± 0.6%, 485.8 ± 35.3 nm, and −38.3 ± 4, respectively. In vitro drug release studies revealed controlled lycopene release from constructed bilosomes, with the drug liberation being based on the Higuchi kinetics model. Transmission electron microscopic evaluation of bilosomes revealed spherical nanovesicles free from aggregates. Moreover, the in vitro and in vivo antibacterial activity of lycopene and its constructed formulations against multidrug-resistant K. pneumoniae isolates were explored. The optimized bilosomes exhibited the lowest minimum inhibitory concentrations ranging from 8 to 32 µg/mL. In addition, scanning electron microscopy revealed remarkable deformation and lysis of the bilosomes-treated bacterial cells. Regarding in vivo investigation, a lung infection model in mice was employed. The tested bilosomes reduced the inflammation and congestion in the treated mice’s lung tissues, resulting in normal-sized bronchioles and alveoli with very few congested vessels. In addition, it resulted in a significant reduction in pulmonary fibrosis. In conclusion, this study investigated the potential activity of the naturally isolated lycopene in controlling infections triggered by multidrug-resistant K. pneumoniae isolates. Furthermore, it introduced bilosomes as a promising biocompatible nanocarrier for modulation of oral lycopene delivery and in vivo antimicrobial activity.

Liposomes for Enhanced Cellular Uptake of Anticancer Agents

Cancers are life threatening diseases and their traditional treatment strategies have numerous limitations which include poor pharmacokinetic profiles, non-specific drug distribution in the body tissues and organs and deprived tumor cells penetration. This attracted the attention of researchers to tailor efficient drug delivery system for anticancer agents to overcome these limitations. Liposomes are one of the newly developed delivery systems for anticancer agents. They are vesicular structures, which were fabricated to enhance drug targeting to tumor tissues either via active or passive targeting. They can be tailored to penetrate tumor cells membrane which is considered the main rate limiting step in antineoplastic therapy. This resulted in enhancing drug cellular uptake and internalization and increasing drug cytotoxic effect. These modifications were achieved via various approaches which included the use of cell-penetrating peptides, the use of lipid substances that can increase liposome fusogenic properties or increase the cell membrane permeability toward amphiphilic drugs, surface modification or ligand targeted liposomes and immuno-liposomes. The modified liposomes were able to enhance anticancer agent's cellular uptake and this was reflected in their ability to destroy tumor tissues. This review outlines different approaches employed for liposomes modification for enhancing anticancer agent's cellular uptake.

Vascular sclerosing effects of bleomycin on cutaneous veins: a pharmacopathologic study on experimental animals

Background:

Varicose veins and the complications of venous disease are common disorders in humans.

Objective:

To study the effects of bleomycin as a potential new sclerosing agent and its adverse events in treating varicose veins.

Methods:

Bleomycin-loaded liposomes 0.1ml was injected in the dorsal ear veins of white New Zealand rabbits. Sodium tetradecyl sulfate was used as a positive control. Normal saline was used as negative control. The blood vessels of the treated ears were photographed before and at one hour and two, eight and 45 days after treatment. Biopsies from the treated areas were obtained for histological examination. Blood samples were collected to determine any possible toxicity.

Results:

Bleomycin by itself was ineffective; therefore, liposomes were used as a vector to deliver bleomycin to the vein lumen. Subsequently, bleomycin started showing its sclerosing effects. Toxicity monitoring showed no apparent hematologic, pulmonary, hepatic or renal toxicities. This study revealed that bleomycin induced vasculitis, which led to vascular occlusion, which was observed on day 1 and day 8. No bleomycin-related injury was noted by histopathological examination of lung sections. The calculation of the lung/body weight coefficient indicated that edema was present in the experimental groups compared with the negative and positive controls.

Study limitations:

Relatively small number of experimental animals used.

Conclusions:

This study showed that bleomycin-loaded liposomes were able to induce vasculitis and vascular occlusion without any toxicity or complications. It might be useful, hence, to treat patients suffering from Varicose veins and other ectatic vascular diseases with this agent.

Bleomycin sulphate loaded nanostructured lipid particles augment oral bioavailability, cytotoxicity and apoptosis in cervical cancer cells

In present investigation, bleomycin sulphate loaded nanostructured lipid particles (BLM-NLPs) were constructed to enhance the oral bioavailability by overwhelming the first pass hepatic metabolism. The particles size and nanoencapsulation efficiency of BLM-NLPs were measured to be 17.4±5.4nm and 45.3±3.4%, respectively. Our studies indicated that the drug was molecularly dispersed in the lipid nanocoacervates, with amorphous geometry, without altering the chemical structure, as ascertained by spectral studies. The nanoformulation, BLM-NLPs was analyzed for dissolution testing, cytotoxicity, apoptosis and cellular uptake in human cervical cancer cell line, HeLa cells. BLM-NLPs released the drug with first order kinetic in simulated intestinal fluid (pH∼6.8±0.1), characterized by initial burst and followed by slow release. Further, an enhanced cytotoxicity (∼5.6 fold lower IC50), improved intracellular concentration (∼4.38 fold) and greater degree of apoptosis was induced by BLM-NLPs in HeLa cells, as compared to BLM alone. Moreover, BLM-NLPs also showed dose-dependent internalization, as evinced by cellular uptake study. The in vivo study indicated a significantly (P<0.0001) smaller elimination rate constant (KE), volume of distribution (Vd) and clearance rate (CLTotal) for BLM-NLPs, as compared to BLM solution in post-oral administrations. This clearly depicts the retention and stability of tailored nanoformulation in intestinal absorption pathway. In addition, our nanoformulation, BLM-NLPs documented significantly (P<0.0001)∼3.4 fold (66.20±2.57%) higher bioavailability than BLM solution (19.56±0.79%). In conclusion, our in vitro and in vivo results warrant the safety, efficacy and potency of tailored nanoformulation in clinical settings.