EGCG Disrupts the LIN28B/Let-7 Interaction and Reduces Neuroblastoma Aggressiveness.

Neuroblastoma (NB) is the most commonly diagnosed extracranial solid tumor in children, accounting for 15% of all childhood cancer deaths. Although the 5-year survival rate of patients with a high-risk disease has increased in recent decades, NB remains a challenge in pediatric oncology, and the identification of novel potential therapeutic targets and agents is an urgent clinical need. The RNA-binding protein LIN28B has been identified as an oncogene in NB and is associated with a poor prognosis. Given that LIN28B acts by negatively regulating the biogenesis of the tumor suppressor let-7 miRNAs, we reasoned that selective interference with the LIN28B/let-7 miRNA interaction would increase let-7 miRNA levels, ultimately leading to reduced NB aggressiveness. Here, we selected (-)-epigallocatechin 3-gallate (EGCG) out of 4959 molecules screened as the molecule with the best inhibitory activity on LIN28B/let-7 miRNA interaction and showed that treatment with PLC/PLGA-PEG nanoparticles containing EGCG (EGCG-NPs) led to an increase in mature let-7 miRNAs and a consequent inhibition of NB cell growth. In addition, EGCG-NP pretreatment reduced the tumorigenic potential of NB cells in vivo. These experiments suggest that the LIN28B/let-7 miRNA axis is a good therapeutic target in NB and that EGCG, which can interfere with this interaction, deserves further preclinical evaluation.

Potentiation of Folate-Functionalized PLGA-PEG nanoparticles loaded with metformin for the treatment of breast Cancer: possible clinical application.

AIM: Folate receptor expression increase up to 30% in breast cancer cells and could be used as a possible ligand to couple to folate-functionalized nanoparticles. Metformin (Met) is an anti-hyperglycemic agent whose anti-cancer properties have been formerly reported. Consequently, in the current study, we aimed to synthesize and characterize folate-functionalized PLGA-PEG NPs loaded with Met and evaluate the anti-cancer effect against the MDA-MB-231 human breast cancer cell line. METHODS: FA-PLGA-PEG NPs were synthesized by employing the W1/O/W2 technique and their physicochemical features were evaluated by FE-SEM, TEM, FTIR, and DLS methods. The cytotoxic effects of free and Nano-encapsulated drugs were analyzed by the MTT technique. Furthermore, RT-PCR technique was employed to assess the expression levels of apoptotic and anti-apoptotic genes. RESULT: MTT result indicated Met-loaded FA-PLGA-PEG NPs exhibited cytotoxic effects in a dose-dependently manner and had more cytotoxic effects relative to other groups. The remarkable down-regulation (hTERT and Bcl-2) and up-regulation (Caspase7, Caspase3, Bax, and p53) gene expression were shown in treated MDA-MB-231 cells with Met-loaded FA-PLGA-PEG NPs. CONCLUSION: Folate-Functionalized PLGA-PEG Nanoparticles are suggested as an appropriate approach to elevate the anticancer properties of Met for improving the treatment effectiveness of breast cancer cells.

Low intensity ultrasound-mediated drug-loaded nanoparticles intravaginal drug delivery: an effective synergistic therapy scheme for treatment of vulvovaginal candidiasis.

PURPOSE: Vulvovaginal candidiasis (VVC) is a mucosal infection of the female lower genital tract for which treatment using conventional antifungal drugs shows limited effectiveness. Herein, amphotericin B-loaded poly(lactic-co-glycolic acid)-polyethylene glycol (PLGA-PEG) nanoparticles (AmB-NPs) were fabricated and combined with low intensity ultrasound (US) to mediate AmB-NPs intravaginal drug delivery to achieve productive synergistic antifungal activity in a rabbit model of VVC. METHODS: Polymeric AmB-NPs were fabricated by a double emulsion method and the physical characteristics and biosafety of nanoparticles were analyzed. The distribution and tissue permeability of nanoparticles after intravaginal ultrasound irradiation (1.0 MHz, 1.0 W/cm2, 5 min, 50% duty ratio) were observed in the vagina. The synergistic therapeutic activity of US-mediated AmB-NPs treatment was evaluated using an experimental rabbit model of VVC. Vaginal C. albicans colony counts, the pathological structure of the vagina epithelium, and Th1/Th2/Th17-type cytokine and oxidative stress levels were analyzed to investigate the therapeutic effect in vivo. RESULTS: The prepared AmB-NPs showed an obvious shell and core structure with uniform size and good dispersion and displayed high biosafety and US-sensitive slow drug release. Ultrasound significantly enhanced nanoparticle transport through the mucus and promoted permeability in the vaginal tissue. US-mediated AmB-NPs treatment effectively increased drug sensitivity, even in the presence of the vaginal mucus barrier in vitro. On the seventh day after treatment in vivo, the combination treatment of AmB-NPs and US significantly reduced the fungal load in the vagina, achieving over 95% clearance rates, and also improved the pathological epithelium structural damage and glycogen secretion function. The expression of Th1 (IFN-γ, IL-2) and Th17 (IL-17) cytokines were significantly increased and Th2 (IL-6, IL-10) cytokines significantly decreased in the US + AmB-NP group. Furthermore, US-mediated AmB-NPs treatment effectively increased C. albicans intracellular reactive oxygen species (ROS) levels and promoted vaginal oxidation and antioxidants to normal levels. CONCLUSION: US-mediated drug-loaded nanoparticles with intravaginal drug delivery exhibited a productive synergistic antifungal effect, which may provide a new non-invasive, safe, and effective therapy for acute or recurrent fungal vaginitis.

The Modified Exenatide Microspheres: PLGA-PEG-PLGA Gel and Zinc-Exenatide Complex Synergistically Reduce Burst Release and Shorten Platform Stage.

The existing exenatide microspheres have the problem of burst release in the early stage, and minimal release in the middle stage which makes it difficult to achieve effective blood drug concentration (platform period). In this study, the modified exenatide microspheres were constructed to address the aforementioned issues. Poly(D,L-lactic-co-glycolic acid) (PLGA) and triblock copolymer with sol-gel conversion characteristics (PLGA-PEG-PLGA gel) were introduced as carriers to prepare microspheres. The hot gel characteristics and hydrophilicity of PLGA-PEG-PLGA gel were utilized to decline the burst release and shorten the platform period. Simultaneously, zinc acetate and exenatide were combined to generate an insoluble complex to further reduce the burst release. Herein, we prepared three types of exenatide microspheres using the solvent evaporation method and investigated their characterization as well as in vitro and in vivo release. According to the experimental findings, the modified exenatide microspheres, i.e., PLGA-PEG-PLGA gel and PLGA co-loaded zinc-exenatide insoluble complex microspheres (Zn-EXT-Gel-MS), had smooth and rounded surfaces, with a particle size of 24.7 µm, and the encapsulation rate reached 89.43%. And it was released for 40 days in vitro, behaving better than the other two microspheres in terms of release behavior. When this product was administered subcutaneously to rats, it produced a comparatively constant plasma exenatide concentration that lasted for 24 days and superior bioavailability than the exenatide microspheres (EXT-MS). The creation of modified exenatide microspheres may serve as a heuristic method for other long-acting medications. Schematic diagram of the synthesis process and release curves of three types of exenatide microspheres in vitro and in vivo.

Microfluidic mixing system for precise PLGA-PEG nanoparticles size control.

In this study, a microfluidic device was employed to produce polymeric nanoparticles (NPs) with well-controlled sizes. The influence of several parameters in the synthesis process, namely, polymer concentration, flow rate and flow rate ratio between the aqueous and organic solutions was investigated. To evaluate the NPs size effect, three diameters were selected (30, 50 and 70 nm). Their cytocompatibility was demonstrated on endothelial cells and macrophages. Additionally, their efficacy to act as drug carriers was assessed in an in vitro inflammatory scenario. NPs loaded and released diclofenac (DCF) in a size-dependent profile (smaller sizes presented lower DCF content and higher release rate). Moreover, 30 nm NPs were the most effective in reducing prostaglandin E2 concentration. Therefore, this study demonstrates that microfluidics can generate stable NPs with controlled sizes, high monodispersity and enhanced batch-to-batch reproducibility. Indeed, NPs size is a crucial parameter for drug encapsulation, release and overall biological efficacy.

Effects of rAmb a 1-Loaded PLGA-PEG Nanoparticles in a Murine Model of Allergic Conjunctivitis.

Ambrosia artemisiifolia (Amb a) contains many allergens. Allergic conjunctivitis caused by Ambrosia artemisiifolia and its related allergen-specific immunotherapy (AIT) are seldom studied at present. poly(DL-lactide-co-glycolide)-polyethylene glycol (PLGA-PEG) is a very good nano-carrier, which has been applied in the medical field. In this context, we studied the immunotherapy effect and potential mechanism of recombinant Amb a 1 (rAmb a 1)-loaded PLGA-PEG nanoparticles. A mouse allergic conjunctivitis model was established with Ambrosia artemisiifolia crude extract, and the nanoparticles were used for AIT through direct observation of conjunctival tissue, degranulation of mast cells in conjunctival tissue, serum-specific antibodies, cytokines and other assessment models. The treatment of nanoparticles enhanced the secretion of T-helper 1 (Th1) cytokine Interferon-gama (IFN-γ) and the production of immunoglobulin G (IgG)2a (IgG2a), inhibited the secretion of T-helper 2 (Th2) cytokine Interleukin (IL)-13 and IL-4 and the level of IgE. Especially, degranulation of mast cells and expression of mast cell protease-1 (MCP-1) in conjunctival tissue was reduced significantly. In this study, we proved that the nanoparticles prepared by rAmb a 1 and PLGA-PEG have an immunotherapy effect on allergic conjunctivitis in mice.

Anticancer effects against colorectal cancer models of chloro(triethylphosphine)gold(I) encapsulated in PLGA-PEG nanoparticles.

Chloro(triethylphosphine)gold(I), (Et3PAuCl hereafter), is an Auranofin (AF)-related compound showing very similar biological and pharmacological properties. Like AF, Et3PAuCl exhibits potent antiproliferative properties in vitro toward a variety of cancer cell lines and is a promising anticancer drug candidate. We wondered whether Et3PAuCl encapsulation might lead to an improved pharmacological profile also considering the likely reduction of unwanted side-reactions that are responsible for adverse effects and for drug inactivation. Et3PAuCl was encapsulated in biocompatible PLGA-PEG nanoparticles (NPs) and the new formulation evaluated in colorectal HCT-116 cancer cells in comparison to the free gold complex. Notably, encapsulated Et3PAuCl (nano-Et3PAuCl hereafter) mostly retains the cellular properties of the free gold complex and elicits even greater cytotoxic effects in colorectal cancer (CRC) cells, mediated by apoptosis and autophagy. Moreover, a remarkable inhibition of two crucial signaling pathways, i.e. ERK and AKT, by nano-Et3PAuCl, was clearly documented. The implications of these findings are discussed.

Formulation, Characterization and Cytotoxicity Effects of Novel Thymoquinone-PLGA-PF68 Nanoparticles.

Thymoquinone has anti-cancer properties. However, its application for clinical use is limited due to its volatile characteristics. The current study aims to develop a polymeric nanoformulation with PLGA-PEG and Pluronics F68 as encapsulants to conserve thymoquinone's (TQ) biological activity before reaching the target sites. Synthesis of nanoparticles was successfully completed by encapsulating TQ with polymeric poly (D, L-lactide-co-glycolide)-block-poly (ethylene glycol) and Pluronics F68 (TQ-PLGA-PF68) using an emulsion-solvent evaporation technique. The size and encapsulation efficiency of TQ-PLGA-PF68 nanoparticles were 76.92 ± 27.38 nm and 94%, respectively. TQ released from these encapsulants showed a biphasic released pattern. Cytotoxicity activity showed that tamoxifen-resistant (TamR) MCF-7 breast cancer cells required a higher concentration of TQ-PLGA-PF68 nanoparticles than the parental MCF-7 cells to achieve IC50 (p < 0.05). The other two resistant subtypes (TamR UACC732 inflammatory breast carcinoma and paclitaxel-resistant (PacR) MDA-MB 231 triple-negative breast cell line) required a lower concentration of TQ-PLGA-PF68 nanoparticles compared to their respective parental cell lines (p < 0.05). These findings suggest that TQ encapsulation with PLGA-PEG and Pluronics F68 is a promising anti-cancer agent in mitigating breast cancer resistance to chemotherapeutics. In future studies, the anti-cancer activity of TQ-PLGA-PF68 with the standard chemotherapeutic drugs used for breast cancer treatment is recommended.

Formulation and In Vitro Characterization of PLGA/PLGA-PEG Nanoparticles Loaded with Murine Granulocyte-Macrophage Colony-Stimulating Factor.

Granulocyte-macrophage colony-stimulating factor (GM-CSF) has demonstrated notable clinical activity in cancer immunotherapy, but it is limited by systemic toxicities, poor bioavailability, rapid clearance, and instability in vivo. Nanoparticles (NPs) may overcome these limitations and provide a mechanism for passive targeting of tumors. This study aimed to develop GM-CSF-loaded PLGA/PLGA-PEG NPs and evaluate them in vitro as a potential candidate for in vivo administration. NPs were created by a phase-separation technique that did not require toxic/protein-denaturing solvents or harsh agitation techniques and encapsulated GM-CSF in a more stable precipitated form. NP sizes were within 200 nm for enhanced permeability and retention (EPR) effect with negative zeta potentials, spherical morphology, and high entrapment efficiencies. The optimal formulation was identified by sustained release of approximately 70% of loaded GM-CSF over 24 h, alongside an average size of 143 ± 35 nm and entrapment efficiency of 84 ± 5%. These NPs were successfully freeze-dried in 5% (w/v) hydroxypropyl-ß-cyclodextrin for long-term storage and further characterized. Bioactivity of released GM-CSF was determined by observing GM-CSF receptor activation on murine monocytes and remained fully intact. NPs were not cytotoxic to murine bone marrow-derived macrophages (BMDMs) at concentrations up to 1 mg/mL as determined by MTT and trypan blue exclusion assays. Lastly, NP components generated no significant transcription of inflammation-regulating genes from BMDMs compared to IFNγ+LPS "M1" controls. This report lays the preliminary groundwork to validate in vivo studies with GM-CSF-loaded PLGA/PEG-PLGA NPs for tumor immunomodulation. Overall, these data suggest that in vivo delivery will be well tolerated.

Subcutaneous Delivery of Albumin: Impact of Thermosensitive Hydrogels.

Albumin demonstrates remarkable promises as a versatile carrier for therapeutic and diagnostic agents. However, noninvasive delivery of albumin-based therapeutics has been largely unexplored. In this study, injectable thermosensitive hydrogels were evaluated as sustained delivery systems for Cy5.5-labeled bovine serum albumin (BSA-Cy5.5). These hydrogels were prepared using aqueous solutions of Poloxamer 407 (P407) or poly(lactide-co-glycolide)-block-poly(ethylene glycol)-block-poly(lactide-co-glycolide) (PLGA-PEG-PLGA), which could undergo temperature-triggered phase transition and spontaneously solidify into hydrogels near body temperature, serving as in situ depot for tunable cargo release. In vitro, these hydrogels were found to release BSA-Cy5.5 in a sustained manner with the release half-life of BSA-Cy5.5 from P407 and PLGA-PEG-PLGA hydrogels at 16 h and 105 h, respectively. Without affecting the bioavailability, subcutaneous administration of BSA-Cy5.5-laden P407 hydrogel resulted in delayed BSA-Cy5.5 absorption, which reached the maximum plasma level (Tmax) at 24 h, whereas the Tmax for subcutaneously administered free BSA-Cy5.5 solution was 8 h. Unexpectedly, subcutaneously injected BSA-Cy5.5-laden PLGA-PEG-PLGA hydrogel did not yield sustained BSA-Cy5.5 plasma level, the bioavailability of which was significantly lower than that of P407 hydrogel (p < 0.05). The near-infrared imaging of BSA-Cy5.5-treated mice revealed that a notable portion of BSA-Cy5.5 remained trapped within the subcutaneous tissues after 6 days following the subcutaneous administration of free solution or hydrogels, suggesting the discontinuation of BSA-Cy5.5 absorption irrespective of the formulations. These results suggest the opportunities of developing injectable thermoresponsive hydrogel formulations for subcutaneous delivery of albumin-based therapeutics.

Preparation and characterization of lutein loaded folate conjugated polymeric nanoparticles.

AIM: To prepare and characterise lutein-loaded polylactide-co-glycolide-polyethylene glycol-folate (PLGA-PEG-FOLATE) nanoparticles and evaluate enhanced uptake in SK-N-BE(2) cells. METHODS: Nanoparticles were prepared using O/W emulsion solvent evaporation and characterised using DLS, SEM, DSC, FTIR and in-vitro release. Lutein-uptake in SK-N-BE(2) cells was determined using flow-cytometry, confocal-microscopy and HPLC. Control was lutein PLGA nanoparticles. RESULTS: The size of lutein-loaded PLGA and PLGA-PEG-FOLATE nanoparticles were 189.6 ± 18.79 nm and 188.0 ± 4.06 nm, respectively. Lutein entrapment was ∼61%(w/w) and ∼73%(w/w) for PLGA and PLGA-PEG-FOLATE nanoparticles, respectively. DSC and FTIR confirmed encapsulation of lutein into nanoparticles. Cellular uptake studies showed ∼1.6 and ∼2-fold enhanced uptake of lutein from PLGA-PEG-FOLATE nanoparticles compared to PLGA nanoparticles and lutein, respectively. Cumulative release of lutein was higher in PLGA nanoparticles (100% (w/w) within 24 h) compared to PLGA-PEG-FOLATE nanoparticles (∼80% (w/w) in 48 h). CONCLUSION: Lutein-loaded PLGA-PEG-FOLATE nanoparticles could be a potential treatment for hypoxic ischaemic encephalopathy.

PLGA-PEG Nanoparticles Show Minimal Risks of Interference with Platelet Function of Human Platelet-Rich Plasma.

The expansion of nanotechnology for drug delivery applications has raised questions regarding the safety of nanoparticles (NPs) due to their potential for interacting at molecular and cellular levels. Although polymeric NPs for drug delivery are formulated using FDA-approved polymers such as lactide- and glycolide-based polymers, their interactions with blood constituents, remain to be identified. The aim of this study was to determine the impact of size-selected Poly-lactide-co-glycolide-polyethylene glycol (PLGA-PEG) NPs on platelet activity. The NPs of 113, 321, and 585 nm sizes, were formulated and their effects at concentrations of 0-2.2 mg/mL on the activation and aggregation of platelet-rich plasma (PRP) were investigated. The results showed that NPs of 113 nm did not affect adenosine diphosphate (ADP)-induced platelet aggregation at any NP concentration studied. The NPs of 321 and 585 nm, at concentrations ≥0.25 mg/mL, reduced ADP-activated platelet aggregation. The platelet activation profile remained unchanged in the presence of investigated NPs. Confocal microscopy revealed that NPs were attached to or internalised by platelets in both resting and activated states, with no influence on platelet reactivity. The results indicate minimal risks of interference with platelet function for PLGA-PEG NPs and that these NPs can be explored as nanocarriers for targeted drug delivery to platelets.

Development of PLGA-PEG-PLGA Hydrogel Delivery System for Enhanced Immunoreaction and Efficacy of Newcastle Disease Virus DNA Vaccine.

The highly contagious Newcastle disease virus (NDV) continues to threaten poultry all over the world. The NDV DNA vaccine is a promising solution to the current Newcastle disease (ND) challenges, and thus an efficient delivery system should be developed to facilitate the efficacy of DNA vaccines. In this study, we developed a DNA vaccine delivery system consisting of a triblock copolymer of poly(lactide co-glycolide acid) and polyethylene glycol (PLGA-PEG-PLGA) hydrogel in which the recombinant NDV hemagglutinin-neuraminidase (HN) plasmid was encapsulated. Its characteristics, security, immune responses, and efficacy against highly virulent NDV were detected. The results showed that the plasmids were gradually released in a sustained manner from the hydrogel, which improved the biological stability of the plasmids and demonstrated a high biocompatibility. The plasmids, when they were incorporated into the hydrogel delivery system, enhanced immune activation and provided 100% protection against the highly virulent NDV strain. Furthermore, we proved that this NDV DNA hydrogel vaccine could improve the lymphocyte proliferation and increase the immunological cytokine production via the PI3K/Akt pathway. These results indicate that the PLGA-PEG-PLGA thermosensitive hydrogel could be a promising delivery system for the NDV DNA vaccine in order to achieve a sustained supply of plasmids and induce potent immune responses.

Local Toxicity of Topically Administrated Thermoresponsive Systems: In Vitro Studies with In Vivo Correlation.

Thermoresponsive materials have the ability to respond to a small change in temperature-a property that makes them useful in a wide range of applications and medical devices. Although very promising, there is only little conclusive data about the cytotoxicity and tissue toxicity of these materials. This work studied the biocompatibility of three Food and Drug Administration approved thermoresponsive polymers: poly( N-isopropyl acrylamide), poly(ethylene glycol)-poly(propylene glycol)-poly(ethylene glycol) tri-block copolymer, and poly(lactic acid-co-glycolic acid) and poly(ethylene glycol) tri-block copolymer. Fibroblast NIH 3T3 and HaCaT keratinocyte cells were used for the cytotoxicity testing and a mouse model for the in vivo evaluation. In vivo results generally showed similar trends as the results seen in vitro, with all tested materials presenting a satisfactory biocompatibility in vivo. pNIPAM, however, showed the highest toxicity both in vitro and in vivo, which was explained by the release of harmful monomers and impurities. More data focusing on the biocompatibility of novel thermoresponsive biomaterials will facilitate the use of existing and future medical devices.

Memantine-Loaded PEGylated Biodegradable Nanoparticles for the Treatment of Glaucoma.

Glaucoma is a multifactorial neurodegenerative disease associated with retinal ganglion cells (RGC) loss. Increasing reports of similarities in glaucoma and other neurodegenerative conditions have led to speculation that therapies for brain neurodegenerative disorders may also have potential as glaucoma therapies. Memantine is an N-methyl-d-aspartate (NMDA) antagonist approved for Alzheimer's disease treatment. Glutamate-induced excitotoxicity is implicated in glaucoma and NMDA receptor antagonism is advocated as a potential strategy for RGC preservation. This study describes the development of a topical formulation of memantine-loaded PLGA-PEG nanoparticles (MEM-NP) and investigates the efficacy of this formulation using a well-established glaucoma model. MEM-NPs <200 nm in diameter and incorporating 4 mg mL-1 of memantine were prepared with 0.35 mg mL-1 localized to the aqueous interior. In vitro assessment indicated sustained release from MEM-NPs and ex vivo ocular permeation studies demonstrated enhanced delivery. MEM-NPs were additionally found to be well tolerated in vitro (human retinoblastoma cells) and in vivo (Draize test). Finally, when applied topically in a rodent model of ocular hypertension for three weeks, MEM-NP eye drops were found to significantly (p < 0.0001) reduce RGC loss. These results suggest that topical MEM-NP is safe, well tolerated, and, most promisingly, neuroprotective in an experimental glaucoma model.

Optimization, Biopharmaceutical Profile and Therapeutic Efficacy of Pioglitazone-loaded PLGA-PEG Nanospheres as a Novel Strategy for Ocular Inflammatory Disorders.

PURPOSE: The main goal of this study was to encapsulate Pioglitazone (PGZ), in biodegradable polymeric nanoparticles as a new strategy for the treatment of ocular inflammatory processes. METHODS: To improve their biopharmaceutical profile for the treatment of ocular inflammatory disorders, nanospheres (NSs) of PGZ were formulated by factorial design with poly (lactic-co-glycolic acid) polyethylene glycol (PLGA-PEG). Interactions drug-polymer have been carried out by spectroscopic (X-ray spectroscopy, FTIR) and thermal methods (DSC). The PGZ-NSs were tested for their in vitro release profile, cytotoxicity, and ocular tolerance (HET-CAM® test); ex vivo corneal permeation, and in vivo inflammatory prevention and bioavailability. RESULTS: The optimized system showed a negative surface charge of -13.9 mV, an average particle size (Zav) of around 160 nm, a polydispersity index (PI) below 0.1, and a high encapsulation efficiency (EE) of around 92%. According to the DSC results, the drug was incorporated into the NSs polymeric matrix. The drug release was sustained for up to 14 h. PGZ-NSs up to 10 µg/ml exhibited no retinoblastoma cell toxicity. The ex vivo corneal and scleral permeation profiles of PGZ-NSs showed that retention and permeation through the sclera were higher than through the cornea. Ocular tolerance in vitro and in vivo demonstrated the non-irritant character of the formulation. CONCLUSION: The in vivo anti-inflammatory efficacy of developed PGZ-NSs indicates this colloidal system could constitute a new approach to prevent ocular inflammation.

Epigallocatechin-3-gallate loaded PEGylated-PLGA nanoparticles: A new anti-seizure strategy for temporal lobe epilepsy.

Temporal lobe epilepsy is the most common type of pharmacoresistant epilepsy in adults. Epigallocatechin-3-gallate has aroused much interest because of its multiple therapeutic effects, but its instability compromises the potential effectiveness. PEGylated-PLGA nanoparticles of Epigallocatechin-3-gallate were designed to protect the drug and to increase the brain delivery. Nanoparticles were prepared by the double emulsion method and cytotoxicity, behavioral, Fluoro-Jade C, Iba1 and GFAP immunohistochemistry studies were carried out to determine their effectiveness. Nanoparticles showed an average size of 169 nm, monodisperse population, negative surface charge, encapsulation efficiency of 95% and sustained release profile. Cytotoxicity assays exhibited that these nanocarriers were non-toxic. Behavioral test showed that nanoparticles reduced most than free drug the number of epileptic episodes and their intensity. Neurotoxicity and immunohistochemistry studies confirmed a decrease in neuronal death and neuroinflammation. In conclusion, Epigallocatechin-3-gallate PEGylated-PLGA nanoparticles could be a suitable strategy for the treatment of temporal lobe epilepsy.

Intra-Articular Formulation of GE11-PLGA Conjugate-Based NPs for Dexamethasone Selective Targeting-In Vitro Evaluation.

Selectively targeted nanoscale drug delivery systems have recently emerged as promising intravenously therapeutic option for most chronic joint diseases. Here, a newly synthetized dodecapeptide (GE11)-polylactide-co-glycolide (PLGA)-based conjugate was used to prepare smart nanoparticles (NPs) intended for intra-articular administration and for selectively targeting Epidermal Growth Factor Receptor (EGFR). GE11-PLGA conjugate-based NPs are specifically uptaken by EGFR-overexpressed fibroblast; such as synoviocytes; which are the primarily cellular component involved in the development of destructive joint inflammation. The selective uptake could help to tune drug effectiveness in joints and to decrease local and systemic side effects. Dexamethasone (DXM) is a glucorticoid drug commonly used in joint disease treatment for both systemic and local administration route. In the present research; DXM was efficiently loaded into GE11-PLGA conjugate-based NPs through an eco-friendly nanoprecipitation method set up for this purpose. DXM loaded GE11-PLGA conjugate-based NPs revealed satisfactory ex vivo cytocompatibility; with proper size (≤150 nm) and good dimensional stability in synovial fluid. Intra-articular formulation was developed embedding DXM loaded GE11-PLGA conjugate-based NPs into thermosetting chitosan-based hydrogel; forming a biocompatible composite hydrogel able to quickly turn from liquid state into gel state at physiological temperature; within 15 min. Moreover; the use of thermosetting chitosan-based hydrogel extends the local release of active agent; DXM.

Revisiting the role of sucrose in PLGA-PEG nanocarrier for potential intranasal delivery.

The efficient design of nanocarriers is a major challenge and must be correlated with the route of administration. Intranasal route is studied for local, systemic or cerebral treatments. In order to develop nanocarriers with suitable properties for intranasal delivery, to achieve brain and to market the product, it is extremely important the simplification of the formulation in terms of raw materials. Surfactants and cryoprotectants are often added to improve structuration and/or storage of polymeric nanoparticles. PLGA-PEG nanocarriers were prepared by nanoprecipitation method evaluating the critical role of sucrose as surfactant-like and cryoprotectant, with the aim to obtain a simpler formulation compared to those proposed in other papers. Photon correlation spectroscopy and Turbiscan analysis show that sucrose is a useful excipient during the preparation process and it effectively cryoprotects nanoparticles. Among the investigated nanocarriers with different degree of PEG, PEGylated PLGA (5%) confers weak interaction between nanoparticles and mucin as demonstrated by thermal analysis and mucin particle method. Furthermore, in vitro biological studies on HT29, as epithelium cell line, does not show cytotoxicity effect for this nanocarrier at all texted concentrations. The selected nanosystem was also studied to load docetaxel, as model drug, and characterized by a technological point of view.

Preparation of Drug-Loaded PLGA-PEG Nanoparticles by Membrane-Assisted Nanoprecipitation.

PURPOSE: The aim of this work is to develop a scalable continuous system suitable for the formulation of polymeric nanoparticles using membrane-assisted nanoprecipitation. One of the hurdles to overcome in the use of nanostructured materials as drug delivery vectors is their availability at industrial scale. Innovation in process technology is required to translate laboratory production into mass production while preserving their desired nanoscale characteristics. METHODS: Membrane-assisted nanoprecipitation has been used for the production of Poly[(D,L lactide-co-glycolide)-co-poly ethylene glycol] diblock) (PLGA-PEG) nanoparticles using a pulsed back-and-forward flow arrangement. Tubular Shirasu porous glass membranes (SPG) with pore diameters of 1 and 0.2 µm were used to control the mixing process during the nanoprecipitation reaction. RESULTS: The size of the resulting PLGA-PEG nanoparticles could be readily tuned in the range from 250 to 400 nm with high homogeneity (PDI lower than 0.2) by controlling the dispersed phase volume/continuous phase volume ratio. Dexamethasone was successfully encapsulated in a continuous process, achieving an encapsulation efficiency and drug loading efficiency of 50% and 5%, respectively. The dexamethasone was released from the nanoparticles following Fickian kinetics. CONCLUSIONS: The method allowed to produce polymeric nanoparticles for drug delivery with a high productivity, reproducibility and easy scalability.