UV spectroscopy and reverse-phase HPLC as novel methods to determine Capreomycin of liposomal fomulations

Bone-targeting exosome nanoparticles activate Keap1 / Nrf2 / GPX4 signaling pathway to induce ferroptosis in osteosarcoma cells

BACKGROUND

In recent years, the development of BMSCs-derived exosomes (EXO) for the treatment of osteosarcoma (OS) is a safe and promising modality for OS treatment, which can effectively deliver drugs to tumor cells in vivo. However, the differences in the drugs carried, and the binding of EXOs to other organs limit their therapeutic efficacy. Therefore, improving the OS-targeting ability of BMSCs EXOs and developing new drugs is crucial for the clinical application of targeted therapy for OS.

RESULTS

In this study, we constructed a potential therapeutic nano platform by modifying BMSCs EXOs using the bone-targeting peptide SDSSD and encapsulated capreomycin (CAP) within a shell. These constructed nanoparticles (NPs) showed the ability of homologous targeting and bone-targeting exosomes (BT-EXO) significantly promotes cellular endocytosis in vitro and tumor accumulation in vivo. Furthermore, our results revealed that the constructed NPs induced ferroptosis in OS cells by prompting excessive accumulation of reactive oxygen species (ROS), Fe2+ aggregation, and lipid peroxidation and further identified the potential anticancer molecular mechanism of ferroptosis as transduced by the Keap1/Nrf2/GPX4 signaling pathway. Also, these constructed NP-directed ferroptosis showed significant inhibition of tumor growth in vivo with no significant side effects.

CONCLUSION

These results suggest that these constructed NPs have superior anticancer activity in mouse models of OS in vitro and in vivo, providing a new and promising strategy for combining ferroptosis-based chemotherapy with targeted therapy for OS.

Liposomes in Cancer Therapy: How Did We Start and Where Are We Now

Since their first discovery in the 1960s by Alec Bangham, liposomes have been shown to be effective drug delivery systems for treating various cancers. Several liposome-based formulations received approval by the U.S. Food and Drug Administration (FDA) and European Medicines Agency (EMA), with many others in clinical trials. Liposomes have several advantages, including improved pharmacokinetic properties of the encapsulated drug, reduced systemic toxicity, extended circulation time, and targeted disposition in tumor sites due to the enhanced permeability and retention (EPR) mechanism. However, it is worth noting that despite their efficacy in treating various cancers, liposomes still have some potential toxicity and lack specific targeting and disposition. This explains, in part, why their translation into the clinic has progressed only incrementally, which poses the need for more research to focus on addressing such translational limitations. This review summarizes the main properties of liposomes, their current status in cancer therapy, and their limitations and challenges to achieving maximal therapeutic efficacy.

In Vitro Efficacy of Curcumin-Loaded Amine-Functionalized Mesoporous Silica Nanoparticles against MCF-7 Breast Cancer Cells

Purpose: Mesoporous silica nanoparticles (MSNs) have drawn substantial interest as drug nanocarriers for breast cancer therapy. Nevertheless, because of the hydrophilic surfaces, the loading of well-known hydrophobic polyphenol anticancer agent curcumin (Curc) into MSNs is usually very low. Methods: For this purpose, Curc molecules were loaded into amine-functionalized MSNs (MSNs-NH₂ -Curc) and characterized using thermal gravimetric analysis (TGA), Fourier-transform infrared (FTIR), field emission scanning electron microscope (FE-SEM), transmission electron microscope (TEM), Brunauer-Emmett-Teller (BET). MTT assay and confocal microscopy, respectively, were used to determine the cytotoxicity and cellular uptake of the MSNs-NH₂ - Curc in the MCF-7 breast cancer cells. Besides, the expression levels of apoptotic genes were evaluated via quantitative polymerase chain reaction (qPCR) and western blot. Results: It was revealed that MSNs-NH₂ possessed high values of drug loading efficiency and exhibited slow and sustained drug release compared to bare MSNs. According to the MTT findings, while the MSNs-NH₂ -Curc were nontoxic to the human non-tumorigenic MCF-10A cells at low concentrations, it could considerably decrease the viability of MCF-7 breast cancer cells compared to the free Curc in all concentrations after 24, 48 and 72 hours exposure times. A cellular uptake study using confocal fluorescence microscopy confirmed the higher cytotoxicity of MSNs-NH₂ -Curc in MCF-7 cells. Further, it was found that the MSNs-NH₂ -Curc could drastically affect the mRNA and protein levels of Bax, Bcl-2, caspase 3, caspase 9, and hTERT relative to the free Curc treatment. Conclusion: Taken together, these preliminary results suggest the amine-functionalized MSNs-based drug delivery platform as a promising alternative approach for Curc loading and safe breast cancer treatment.

The determination of capreomycin in human plasma by LC-MS/MS using ion-pairing chromatography and solid-phase extraction

A bioanalytical method was developed and validated for the quantification of capreomycin (Cm) analogs, Cm IA and Cm IB, in human plasma. This implemented ion-pairing solid phase extraction, followed by ion-pairing high-performance liquid chromatography, with tandem mass spectrometry detection. Chromatographic separation was achieved using a Discovery C18 , 5 μm, 4.6 × 50 mm analytical column. An isocratic mobile phase consisting of water and acetonitrile with 0.1% formic acid and 4mm heptafluorobutyric acid (80:20; v/v) was used at a flow-rate of 500 μL/min. An AB Sciex API 3000 mass spectrometer at unit resolution, in multiple reaction monitoring mode, was used for detection. Electrospray ionization was used for ion production. The method was successfully validated for the range 469-30,000 ng/mL for Cm IA and for Cm IB, with cefotaxime as the internal standard. The within- and between-day precision determinations for Cm IA and IB, expressed as the percentage coefficient of variation, were < 20.0% at the lower limit of quantification (LLOQ) and < 8.2% at all other test concentrations. Recovery of both analogs was > 72.3% and reproducible at the low, medium and high end of the calibration range. No significant matrix effects were observed for the analyte. The assay performed well when applied to clinical samples generated from children in a clinical multidrug resistant tuberculosis research study in South Africa.

Fighting tuberculosis: old drugs, new formulations

This review reports the state of the art on innovative drug delivery strategies designed for antitubercular chemotherapeutics. The introduction contains the fundamental biological background concerning tuberculosis and a review of the current antitubercular therapy, and is followed by a critical report of the micrometric and nanometric particulate systems designed and investigated to improve tuberculosis chemotherapy.

Preparation and in Vivo Evaluation of a Dry Powder for Inhalation of Capreomycin

PURPOSE

To develop an aerosol system for efficient local lung delivery of a tuberculostatic drug.

METHODS

The antibiotic, capreomycin sulfate, was spray dried to form a dry powder aerosol. The chemical content and physical properties of resulting particles were assessed under various storage conditions. Plasma concentrations of capreomycin after insufflation into guinea pigs were evaluated at three doses, and compared to IV and IM administration of a capreomycin solution.

RESULTS

Dry powder aerosols containing capreomycin were formulated to enable efficient delivery of large drug masses to the lungs of guinea pigs. Aerosols loaded with 73% CS were shown to possess good aerosolization properties and physical-chemical stability for up to 3 months at room temperature. Upon insufflation into guinea pigs, the amount of CS reaching the bloodstream was significantly lower compared to IV or IM administration, but resulted in a significantly longer drug half-life.

CONCLUSIONS

The results indicate that large doses of capreomycin in dry powder form can be efficiently delivered to the lungs of guinea pigs, which may result in high local drug exposure but significantly reduced systemic exposure as suggested by plasma concentrations in the present studies. These systems have considerable potential to provide more effective therapy for MDR-TB.

Inhaled large porous particles of capreomycin for treatment of tuberculosis in a guinea pig model

Capreomycin is used for the treatment of multidrug-resistant tuberculosis (MDR-TB), but it is limited therapeutically by its severe side effects. The objectives of the present studies were (i) to design low-density porous capreomycin sulfate particles for efficient pulmonary delivery to improve local and systemic drug bioavailability and capacity to reduce the bacillary load in the lungs in a manner similar to that achieved with intramuscular injections; (ii) to determine pharmacokinetic parameters after pulmonary administration of these capreomycin particles; and (iii) to evaluate the efficacy of these particles in treating animals in a small-aerosol-inoculum guinea pig model of TB. Capreomycin particles were manufactured by spray drying and characterized in terms of size and drug content. Pharmacokinetic parameters were determined by noncompartmental methods with healthy guinea pigs after administration of capreomycin particles by insufflation. The efficacy of the particles was evaluated by histopathological analysis and in terms of wet organ weight and bacterial burden in TB-infected animals. Lungs of animals receiving a 14.5-mg/kg dose of capreomycin particles showed significantly lower wet weights and smaller bacterial burdens than those of animals receiving any other treatment. These results were supported by histopathological analysis. The feasibility of inhaling capreomycin in a novel powder form, with the ultimate objective of the treatment of MDR-TB, is demonstrated by pharmacokinetic and pharmacodynamic studies with guinea pigs. If applied to humans with MDR-TB, such a therapeutic approach might simplify drug delivery by eliminating injections and might reduce adverse effects through lowering the dose.

Development of liposomal capreomycin sulfate formulations: Effects of formulation variables on peptide encapsulation

PURPOSE

The aim of this work was the investigation of the effects of preparation variables on drug content for the development of capreomycin sulfate (CS) liposomal formulations as potential aerosol antitubercular agents.

METHODS

Dipalmitoylphosphatidylcholine (DPPC), hydrogenated phosphatidylcholine (HPC) and distearoylphosphatidylcholine (DSPC) were used for liposome preparation. A freeze-thawing method was chosen for CS encapsulation. Peptide entrapment, size and morphology were evaluated by UV spectrophotometry, photocorrelation spectroscopy (PCS) and transmission electron microscopy (TEM), respectively. A 2(3) full factorial protocol was designed to evaluate the conditions for CS encapsulation improvement.

RESULTS

Peptide content ranged between 1 and 8%. Vesicles showed a narrow size distribution, with average diameters around 1 microm and a good morphology. A mathematical model was generated for each liposomal system and check point analyses revealed good agreement between experimental and predicted values. DPPC liposomes were found to provide the highest CS content.

CONCLUSIONS

Peptide content was successfully increased by assessing formulation variable effects using a 2(3) factorial design that proved to be a time saving method helpful in developing new CS liposomal formulations for a possible application in aerosol antitubercular therapies.