Effect of Nanoparticle Weight on the Cellular Uptake and Drug Delivery Potential of PLGA Nanoparticles

Maximizing liposome tumor delivery by hybridizing with tumor-derived extracellular vesicles

Extracellular vesicles (EVs) have gained widespread interest due to their potential in the diagnosis and treatment of inflammation, autoimmune diseases, and cancers. EVs are lipidic vesicles comprising vesicles of endosomal origin called exosomes, microvesicles from membrane shedding, and apoptotic bodies from programmed cell death membrane blebbing that carry complex sets of cargo from their cells of origin, including proteins, lipids, mRNA, and DNA. EVs are rich in integrin proteins that facilitate intrinsic cellular communication to deliver their cargo contents and can also be used as biomarkers to study respective cellular conditions. Within this background, we hypothesized that when these EVs are hybridized with synthetic liposomes, it would help navigate the hybrid construct in the complex biological environment to find its target. Toward this endeavor, we have hybridized a synthetic liposome with EVs (herein called LEVs) derived from mouse breast cancer (4T1 tumors) cells and incorporated a rhodamine-B/near-infrared fluorescent dye to investigate their potential for cellular targeting and tumor delivery. Using membrane extrusion, we have successfully hybridized both entities resulting in the formation of LEVs and characterized their colloidal properties and stability over a period. While EVs are broadly dispersed nano- and micron-sized vesicles, LEVs are engineered as monodispersed with an average hydrodynamic size of 140 ± 5. Using immunoblotting and ELISA, we monitored and quantified the EV-specific protein CD63 and other characteristic proteins such as CD9 and CD81, which were taken as a handle to ensure the reproducibility of EVs and thus LEVs. These LEVs were further challenged with mice bearing orthotopic 4T1 breast tumors and the LEV uptake was found to be maximum in tumors and organs like the liver, spleen, and lungs when compared to control PEGylated liposomes in live animal imaging. Likewise, the constructs were capable of finding lung metastasis as observed in ex vivo imaging. We anticipate that this study can open avenues for drug delivery solutions that are superior in target recognition.

Nanodroplets Engineered with Folate Carbon Dots for Enhanced Cancer Cell Uptake toward Theranostic Application

The research in nanotherapeutics is rapidly advancing, particularly in the realm of nanoconstructs for drug delivery. This study introduces folate-based carbon dot-decorated nanodroplets (f-Dnm), synthesized from a binary mixture of negatively charged folic acid carbon dots (f-CDs) and cationic-branched polyethylenimine (PEI). The uniformly spherical nanodroplets with an average diameter of 115 ± 15 nm exhibit notable photoluminescence. Surface potential analysis reveals a significant change upon coacervation, attributed to strong electrostatic interactions between f-CD and PEI. The engineered nanodroplets show excellent colloidal and photostability even after 6 months of storage at room temperature. The pH-dependent self-assembly and disassembly properties of f-Dnm are explored for drug loading and release studies using doxorubicin (DOX) as a model anticancer drug. Moreover, the f-Dnm nanocarrier demonstrates significantly higher drug loading capabilities (∼90%). In vitro release studies of doxorubicin-loaded f-Dnm [f-Dnm(DOX)] reveal 5 times higher drug release at lysosomal pH 5.4 compared to that at physiological blood pH 7.4. Cytocompatibility assessments using the MTT assay on HeLa, A549, and NIH-3T3 cells confirm the nontoxic nature of f-Dnm, even at high concentrations. Additionally, f-Dnm(DOX) exhibits higher cytotoxicity in HeLa cells compared to f-CD(DOX) at similar DOX concentrations. Cellular uptake studies show an increased uptake of f-Dnm in folate receptor-positive HeLa and MDA-MB 231 cells. Hemolysis assay validated the biocompatibility of the developed formulation. Overall, these engineered nanodroplets represent a class of nontoxic nanocarriers that offer promising potential as nanotherapeutics for folate receptor-positive cells.

A Review of the Potential of Poly-(lactide-co-glycolide) Nanoparticles as a Delivery System for an Active Antimycobacterial Compound, 7-Methyljuglone

7-Methyljuglone (7-MJ) is a pure compound isolated from the roots of Euclea natalensis A. DC., a shrub indigenous to South Africa. It exhibits significant promise as a potential treatment for the highly communicable disease tuberculosis (TB), owing to its effective antimycobacterial activity against Mycobacterium tuberculosis. Despite its potential therapeutic benefits, 7-MJ has demonstrated in vitro cytotoxicity against various cancerous and non-cancerous cell lines, raising concerns about its safety for consumption by TB patients. Therefore, this review focuses on exploring the potential of poly-(lactide-co-glycolic) acid (PLGA) nanoparticles as a delivery system, which has been shown to decrease in vitro cytotoxicity, and 7-MJ as an effective antimycobacterial compound.

Enhancing Therapeutic Efficacy against Brucella canis Infection in a Murine Model Using Rifampicin-Loaded PLGA Nanoparticles

The in vivo efficacy of rifampicin encapsulated in poly(lactic-co-glycolic acid) (PLGA) nanoparticles was evaluated for the treatment of BALB/c mice experimentally infected with Brucella canis. The PLGA nanoparticles loaded with rifampicin (RNP) were prepared using the single emulsification-solvent evaporation technique, resulting in nanoparticles with a hydrodynamic diameter of 138 ± 6 nm. The zeta potential and polydispersity index values indicated that the system was relatively stable with a narrow size distribution. The release of rifampicin from the nanoparticles was studied in phosphate buffer at pH 7.4 and 37 °C. The release profile showed an initial burst phase, followed by a slower release stage attributed to nanoparticle degradation and relaxation, which continued for approximately 30 days until complete drug release. A combined model of rifampicin release, accounting for both the initial burst and the degradation-relaxation of the nanoparticles, effectively described the experimental data. The efficacy of RNP was studied in vivo; infected mice were treated with free rifampicin at concentrations of 2 mg per kilogram of mice per day (C1) and 4 mg per kilogram of mice per day (C2), as well as equivalent doses of RNP. Administration of four doses of the nanoparticles significantly reduced the B. canis load in the spleen of infected BALB/c mice. RNP demonstrated superior effectiveness compared to the free drug in the spleen, achieving reductions of 85.4 and 49.4%, respectively, when using C1 and 93.3 and 61.8%, respectively, when using C2. These results highlight the improved efficacy of the antibiotic when delivered through nanoparticles in experimentally infected mice. Therefore, the RNP holds promise as a potential alternative for the treatment of B. canis.