Search Results (58)

Background/Objectives: The limited permeability of the blood–brain barrier (BBB) to biotherapeutics is a major challenge in the treatment of brain tumors. The nose-to-brain (N2B) delivery approach, which bypasses the BBB, offers a promising alternative way to treat these tumors. The aim of this work was to develop PLGA nanoparticles for N2B delivery of biodrugs using trastuzumab (TZB) as a paradigm. Methods: An in vitro model was used to evaluate the ability of PLGA nanoparticles to enhance passage through the nasal epithelium. We also compared the passage of loaded TZB versus unencapsulated TZB across an in vitro BBB model simulating systemic administration of TZB. TZB-loaded PLGA nanoparticles (NP-TZBs) were prepared using a double emulsion method followed by solvent evaporation and characterized for various properties, including particle size, polydispersity index, zeta potential, morphology, encapsulation efficiency, and drug loading capacity and release kinetics. TZB functionality was assessed after release from NP or passage through an in vitro barrier model. The permeability of TZB and NP-TZBs through in vitro models of nasal epithelium and BBB was investigated. Results: NP-TZBs exhibited an average size of about 200 nm with a polydispersity index of less than 20%, neutral charge, and a loading efficiency of 67%. Transmission electron microscopy revealed spherical nanoparticles with a smooth surface. Importantly, the TZB released from the nanoparticles retained all of its physicochemical properties and functionality. We observed that the NP-TZB formulation results in at least a nine-fold increase in TZB permeability across the nasal epithelium 24 h post-exposure, depending on the exposure conditions, but shows no significant improvement across the BBB model. The TZB released in the basal compartment is fully functional and able to recognize HER2 expressed on the surface of breast tumor BT474 cells. Conclusions: Using compounds already validated for clinical use, we were able to develop a formulation that allowed efficient passage of TZB across an in vitro nasal epithelial model. In contrast, no passage was observed across the BBB, supporting the notion of the superiority of the nose–brain route over systemic injection for in vivo delivery of TZB to the central nervous system. Full article

Background and objectives: The use of polymeric nanoparticles (NPs) in drug delivery systems offers the advantages of enhancing drug efficacy and minimizing side effects; Methods: In this study, L-threonine polyurethane (LTPU) NPs have been fabricated by water-in-oil-in-water emulsion and solvent evaporation using biodegradable and biocompatible LTPU. This polymer was pre-synthesized through the use of an amino acid-based chain extender, desaminotyrosyl L-threonine hexyl ester (DLTHE), where urethane bonds are formed by poly(lactic acid)-poly(ethylene glycol)-poly(lactic acid) (PLA-PEG-PLA) triblock copolymer and 1,6-hexamethylene diisocyanate (HDI). LTPU is designed to be degraded by hydrolysis and enzymatic activity due to the presence of ester bonds and peptide bonds within the polymer backbone. LTPU NPs were fabricated by water-in-oil-in-water double emulsion solvent evaporation methods; Results: The polymerization of LTPU was confirmed by ¹H-NMR, ¹³C-NMR, and FT-IR spectroscopies. The molecular weights and polydispersity, determined with GPC, were 28,800 g/mol and 1.46, respectively. The morphology and size of NPs, characterized by DLS, FE-SEM, TEM, and confocal microscopy, showed smooth and spherical particles with diameters less than 200 nm; Conclusions: In addition, the drug loading, encapsulation efficiency, and drug release profiles, using UV-Vis spectroscopy, showed the highest encapsulation efficiency with 2.5% carboplatin and sustained release profile. Full article

Local Khulays clay was modified to prepare polystyrene clay nanocomposite (PCN) coatings on carbon steel. The PCN coatings were added to microcapsules (MCs) loaded with the corrosion inhibitor PCN(MC). The microcapsules were prepared by the encapsulation of rare-earth metal Ce⁺³ ions and isobutyl silanol into polystyrene via the double emulsion solvent evaporation (DESE) technique. From characterization techniques, Fourier-transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), transmission electron microscopy (TEM), and scanning electron microscopy (SEM) with EDX. SEM and FT-IR confirmed the success of the preparation of the PCN(MC). Nanoindentation tests were performed on the thin-film samples. A significant reduction in both the hardness and the reduced modulus was observed for the PCN film compared to the PS film. Electrochemical impedance spectroscopy (EIS) and electrochemical frequency modulation (EFM) all showed an enhanced protection efficiency (%PE) of 3% PCN(MC) over 3% PCN at high temperatures and at different times. The smart coatings were proven by applying the thermal and the mechanical triggers for the 3% PCN(MC) coating. The mechanism of the release of inhibitors was discussed. The self-healing properties of 3% PCN(MC) were evaluated. The enhanced properties of the developed PCN(MC) coatings make them attractive for potential applications in the oil and other industries. Full article

Salmonid rickettsial septicemia (SRS), caused by Piscirickettsia salmonis, has been the most severe health concern for the Chilean salmon industry. The efforts to control P. salmonis infections have focused on using antibiotics and vaccines. However, infected salmonids exhibit limited responses to the treatments. Here, we developed a poly (D, L-lactide-glycolic acid) (PLGA)-nanosystem functionalized with Atlantic salmon IgM (PLGA-IgM) to specifically deliver florfenicol into infected cells. Polymeric nanoparticles (NPs) were prepared via the double emulsion solvent-evaporation method in the presence of florfenicol. Later, the PLGA-NPs were functionalized with Atlantic salmon IgM through carbodiimide chemistry. The nanosystem showed an average size of ~380–410 nm and a negative surface charge. Further, florfenicol encapsulation efficiency was close to 10%. We evaluated the internalization of the nanosystem and its impact on bacterial load in SHK-1 cells by using confocal microscopy and qPCR. The results suggest that stimulation with the nanosystem elicits a decrease in the bacterial load of P. salmonis when it infects Atlantic salmon macrophages. Overall, the IgM-functionalized PLGA-based nanosystem represents an alternative to the administration of antibiotics in salmon farming, complementing the delivery of antibiotics with the stimulation of the immune response of infected macrophages. Full article

Docetaxel (DTX) and betulinic acid (BA) co-encapsulated poly-lactic co-glycolic acid (PLGA) nanoparticles (NPs) were developed for enhanced lung cancer activity in vitro. Poly (lactic-co-glycolic acid) (PLGA) was used as an encapsulating polymer along with polyvinyl alcohol (PVA) as a stabilizing base to formulate NPs with the double-emulsion solvent evaporation method to study the size and potential, along with the surface morphology and in vitro release, of NPs. Cell culture studies like in vitro cellular uptake, apoptosis, and cell cycle arrest were performed in an in vitro cytotoxicity study to access the NP’s effect in the A549 human lung cancer cell line. The emulsification solvent evaporation technique produced smooth spherical nanoparticles of small sizes with a relatively narrow size distribution (147.2 ± 12.29 nm). On the A549 cell line, the formulation showed higher cytotoxicity (6.43 ± 0.11, 4.21 ± 0.32, and 1.17 ± 0.23 µmol for 24, 48, and 72 h, respectively) compared to the free drug due to an increase in vitro cellular uptake. Apoptosis and cell cycle analysis also confirmed the effectiveness of the prepared NPs. In vitro studies have proven the tumor-targeting potential of DTX-BA-NPs in A549 cell lines and could be future medication for lung cancer treatment. Full article

Antimicrobial peptides (AMPs) are antibiotic candidates; however, their instability and protease susceptibility limit clinical applications. In this study, the polylactic acid–glycolic acid (PLGA)–polyvinyl alcohol (PVA) drug delivery system was screened by orthogonal design using the double emulsion–solvent evaporation method. NZ2114 nanoparticles (NZ2114-NPs) displayed favorable physicochemical properties with a particle size of 178.11 ± 5.23 nm, polydispersity index (PDI) of 0.108 ± 0.10, ζ potential of 4.78 ± 0.67 mV, actual drug-loading rate of 4.07 ± 0.37%, encapsulation rate of 81.46 ± 7.42% and cumulative release rate of 67.75% (120 h) in PBS. The results showed that PLGA encapsulation increased HaCaT cell viability by 20%, peptide retention in 50% serum by 24.12%, and trypsin tolerance by 4.24-fold. Meanwhile, in vitro antimicrobial assays showed that NZ2114-NPs had high inhibitory activity against Staphylococcus epidermidis (S. epidermidis) (4–8 μg/mL). Colony counting and confocal laser scanning microscopy (CLSM) confirmed that NZ2114-NPs were effective in reducing the biofilm thickness and bacterial population of S. epidermidis G4 with a 99% bactericidal rate of persister bacteria, which was significantly better than that of free NZ2114. In conclusion, the results demonstrated that PLGA nanoparticles can be used as a reliable NZ2114 delivery system for the treatment of biofilm infections caused by S. epidermidis. Full article

Haemonchus contortus is a gastrointestinal parasite that adversely impacts small ruminants, resulting in a notable reduction in animal productivity. In the current investigation, we developed a nanovaccine by encapsulating the recombinant protein rHcES-15, sourced from the excretory/secretory products of H. contortus, within biodegradable poly (D, L-lactide-co-glycolide) (PLGA) nanoparticles (NPs). The development of this nanovaccine involved the formulation of PLGA NPs using a modified double emulsion solvent evaporation technique. Scanning electron microscopy (SEM)verified the successful encapsulation of rHcES-15 within PLGA NPs, exhibiting a size range of 350–400 nm. The encapsulation efficiency (EE) of the antigen in the nanovaccine was determined to be 72%. A total of forty experimental mice were allocated into five groups, with the nanovaccine administered on day 0 and the mice euthanized at the end of the 14-day trial. The stimulation index (SI) from the mice subjected to the nanovaccine indicated heightened lymphocyte proliferation (*** p < 0.001) and a noteworthy increase in anti-inflammatory cytokines (IL-4, IL-10, and IL-17). Additionally, the percentages of T-cells (CD4⁺, CD8⁺) and dendritic cell phenotypes (CD83⁺, CD86⁺) were significantly elevated (** p < 0.01, *** p < 0.001) in mice inoculated with the nanovaccine compared to control groups and the rHcES-15 group. Correspondingly, higher levels of antigen-specific serum immunoglobulins (IgG1, IgG2a, IgM) were observed in response to the nanovaccine in comparison to both the antigenic (rHcES-15) and control groups (* p < 0.05, ** p < 0.01). In conclusion, the data strongly supports the proposal that the encapsulation of rHcES-15 within PLGA NPs effectively triggers immune cells in vivo, ultimately enhancing the antigen-specific adaptive immune responses against H. contortus. This finding underscores the promising potential of the nanovaccine, justifying further investigations to definitively ascertain its efficacy. Full article

Melanin is an insoluble, amorphous polymer that forms planar sheets that aggregate naturally to create colloidal particles with several biological functions. Based on this, here, a preformed recombinant melanin (PRM) was utilized as the polymeric raw material to generate recombinant melanin nanoparticles (RMNPs). These nanoparticles were prepared using bottom-up (nanocrystallization—NC, and double emulsion–solvent evaporation—DE) and top-down (high-pressure homogenization—HP) manufacturing approaches. The particle size, Z-potential, identity, stability, morphology, and solid-state properties were evaluated. RMNP biocompatibility was determined in human embryogenic kidney (HEK293) and human epidermal keratinocyte (HEKn) cell lines. RMNPs prepared by NC reached a particle size of 245.9 ± 31.5 nm and a Z-potential of −20.2 ± 1.56 mV; 253.1 ± 30.6 nm and −39.2 ± 0.56 mV compared to that obtained by DE, as well as RMNPs of 302.2 ± 69.9 nm and −38.6 ± 2.25 mV using HP. Spherical and solid nanostructures in the bottom-up approaches were observed; however, they were an irregular shape with a wide size distribution when the HP method was applied. Infrared (IR) spectra showed no changes in the chemical structure of the melanin after the manufacturing process but did exhibit an amorphous crystal rearrangement according to calorimetric and PXRD analysis. All RMNPs presented long stability in an aqueous suspension and resistance to being sterilized by wet steam and ultraviolet (UV) radiation. Finally, cytotoxicity assays showed that RMNPs are safe up to 100 μg/mL. These findings open new possibilities for obtaining melanin nanoparticles with potential applications in drug delivery, tissue engineering, diagnosis, and sun protection, among others. Full article

Autoinducers AI-1 and AI-2 play an important role in bacterial quorum sensing (QS), a form of chemical communication between bacteria. The autoinducer N-octanoyl-L-Homoserinehomoserine lactone (C8-HSL) serves as a major inter- and intraspecies communicator or ‘signal’, mainly for Gram-negative bacteria. C8-HSL is proposed to have immunogenic properties. The aim of this project is to evaluate C8-HSL as a potential vaccine adjuvant. For this purpose, a microparticulate formulation was developed. The C8-HSL microparticles (MPs) were formulated by a water/oil/water (W/O/W) double-emulsion solvent evaporation method using PLGA (poly (lactic-co-glycolic acid)) polymer. We tested C8-HSL MPs with two spray-dried bovine serum albumin (BSA)-encapsulated bacterial antigens: colonization factor antigen I (CFA/I) from Escherichia coli (E. coli.) and the inactive protective antigen (PA) from Bacillus anthracis (B. anthracis). We formulated and tested C8-HSL MP to determine its immunogenicity potential and its ability to serve as an adjuvant with particulate vaccine formulations. An in vitro immunogenicity assessment was performed using Griess’s assay, which indirectly measures the nitric oxide radical (NOˑ) released by dendritic cells (DCs). The C8-HSL MP adjuvant was compared with FDA-approved adjuvants to determine its immunogenicity potential. C8-HSL MP was combined with particulate vaccines for measles, Zika and the marketed influenza vaccine. The cytotoxicity study showed that MPs were non-cytotoxic toward DCs. Griess’s assay showed a comparable release of NOˑ from DCs when exposed to CFA and PA bacterial antigens. Nitric oxide radical (NOˑ) release was significantly higher when C8-HSL MPs were combined with particulate vaccines for measles and Zika. C8-HSL MPs showed immunostimulatory potential when combined with the influenza vaccine. The results showed that C8-HSL MPs were as immunogenic as FDA-approved adjuvants such as alum, MF59, and CpG. This proof-of-concept study showed that C8-HSL MP displayed adjuvant potential when combined with several particulate vaccines, indicating that C8-HSL MPs can increase the immunogenicity of both bacterial and viral vaccines. Full article

Background: The Box–Behnken design of experiments (BBD) is a statistical modelling technique that allows the determination of the significant factors in developing nanoparticles (NPs) using a limited number of runs. It also allows the prediction of the best levels of variables to obtain the desired characteristics (size, charge, and encapsulation efficiency) of the NPs. The aim of this study was to examine the effect of the independent variables (amount of polymer and drug, and surfactant concentration) and their interaction on the characteristics of the irinotecan hydrochloride (IRH)-loaded polycaprolactone (PCL) NPs and to determine the most optimum conditions for producing the desired NPs. Methods: The development of the NPs was carried out by a double emulsion solvent evaporation technique with yield enhancement. The NPs data were fitted in Minitab software to obtain the best fit model. Results: By using BBD, the most optimum conditions for producing the smallest size, highest magnitude of charge, and highest EE% of PCL NPs were predicted to be achieved by using 61.02 mg PCL, 9 mg IRH, and 4.82% PVA, which would yield 203.01 nm, −15.81 mV, and 82.35% EE. Conclusion: The analysis by BBD highlighted that the model was a good fit to the data, confirming the suitability of the design of the experiments. Full article

Malignant pleural mesothelioma (MPM) is a rare and aggressive cancer affecting the pleural lining of the lungs. Celastrol (Cela), a pentacyclic triterpenoid, has demonstrated promising therapeutic potential as an antioxidant, anti-inflammatory, neuroprotective agent, and anti-cancer agent. In this study, we developed inhaled surface-modified Cela-loaded poly(lactic-co-glycolic) acid (PLGA) microparticles (Cela MPs) for the treatment of MPM using a double emulsion solvent evaporation method. The optimized Cela MPs exhibited high entrapment efficiency (72.8 ± 6.1%) and possessed a wrinkled surface with a mean geometric diameter of ~2 µm and an aerodynamic diameter of 4.5 ± 0.1 µm, suggesting them to be suitable for pulmonary delivery. A subsequent release study showed an initial burst release up to 59.9 ± 2.9%, followed by sustained release. The therapeutic efficacy of Cela MPs was evaluated against four mesothelioma cell lines, where Cela MP exhibited significant reduction in IC₅₀ values, and blank MPs produced no toxicity to normal cells. Additionally, a 3D-spheroid study was performed where a single dose of Cela MP at 1.0 µM significantly inhibited spheroid growth. Cela MP was also able to retain the antioxidant activity of Cela only while mechanistic studies revealed triggered autophagy and an induction of apoptosis. Therefore, these studies highlight the anti-mesothelioma activity of Cela and demonstrate that Cela MPs are a promising inhalable medicine for MPM treatment. Full article

Nanoparticles can be used as drug carriers in various applications (e.g., in pulmonary drug delivery and mucosal vaccination). For further investigations, such as drug release studies, as well as for cell and tissue targeting, particles with defined properties are needed. The purpose of the study was to show a multi-step systematic method utilising quality by design to ensure the quality of ovalbumin loaded polylactic-co-glycolic acid nanoparticles (OVA-PLGA-NP), which can be delivered to the lung, and to gain knowledge of the preparation method (double-emulsion solvent evaporation method) in an early development process. Within a definitive screening design, several process parameters (OVA, PLGA and stabiliser concentrations, stirring time and stirring speed of inner emulsion and stirring time and stirring speed of double emulsion) were varied to analyse their impact on resulting properties (z-average, PDI, loading efficiency and loading capacity). The results showed that the preparation of the inner emulsion mainly influenced the drug loading, while the parameters of the second emulsifying step controlled the size. Then a central composite response surface design was used to achieve a predictable OVA-PLGA-NP with an average particle size of 700 nm and high drug-loading. This also enabled the demonstration of curvature and interaction of the stabiliser and the PLGA concentration. Full article

The aim of the present study is to develop Doxorubicin–Erlotinib nanoparticles (Dox–Erlo NPs) and folate-armored Dox–Erlo-NP conjugates for targeting glioma cancer. Glioma is one of the most common progressive cancerous growths originating from brain glial cells. However, the blood–brain barrier (BBB) is only semi-permeable and is highly selective as to which compounds are let through; designing compounds that overcome this constraint is therefore a major challenge in the development of pharmaceutical agents. We demonstrate that the NP conjugates studied in this paper may ameliorate the BBB penetration and enrich the drug concentration in the target bypassing the BBB. NPs were prepared using a biopolymer with a double-emulsion solvent evaporation technique and functionalized with folic acid for site-specific targeting. Dox–Erlo NPs and Dox–Erlo-NP conjugates were extensively characterized in vitro for various parameters. Dox–Erlo NPs and Dox–Erlo-NP conjugates incurred a z-average of 95.35 ± 10.25 nm and 110.12 ± 9.2 nm, respectively. The zeta potentials of the Dox–Erlo NPs and Dox–Erlo-NP conjugates were observed at −18.1 mV and −25.1 mV, respectively. A TEM image has shown that the NPs were well-dispersed, uniform, de-aggregated, and consistent. A hemolytic assay confirmed hemocompatibility with the developed formulation and that it can be safely administered. Dox–Erlo-NP conjugates significantly reduced the number of viable cells to 24.66 ± 2.08% and 32.33 ± 2.51% in U87 and C6 cells, respectively, and IC50 values of 3.064 µM and 3.350 µM in U87 and C6 cells were reported after 24 h, respectively. A biodistribution study revealed that a significant concentration of Dox and Erlo were estimated in the brain relative to drug suspension. Dox–Erlo-NP conjugates were also stable for three months. The findings suggest that the developed Dox–Erlo-NP conjugates may be a promising agent for administration in glioma therapy. Full article

Polymer–Clay Nanocomposite (PCN) coatings were prepared using the solution intercalation method. The raw Khulays clay was treated with NaCl to produce sodium clay (NaC). Thereafter, Cetyl Pyridinium Chloride (CPC) was used to convert NaC into the organic clay form (OC). PCN was prepared by adding polystyrene as the matrix to different weights of OC to prepare 1 wt.% and 3 wt.% PCN. To enhance the coating protection of C-steel in NaCl solution, PCN coatings were added to microcapsules loaded with some corrosion inhibitors PCN (MC). The microcapsules are prepared by the encapsulation of rare-earth metal Ce⁺³ ions and Isobutyl silanol into polystyrene via the Double Emulsion Solvent Evaporation (DESE) technique. Characterization techniques such as FTIR, X-Ray Diffraction (XRD), and Transmission Electron Microscopy (TEM) were employed. FTIR confirmed the success of the preparation, while XRD and TEM revealed an intercalated structure of 1 wt.% PCN while 3 wt.% PCN has a fully exfoliated structure. Electrochemical Impedance Spectroscopy (EIS), Electrochemical Frequency Modulation (EFM), and Potentiodynamic Polarization showed an enhanced protection efficiency of PCN (MC) coatings. The results demonstrated that the corrosion resistance (R_Corr) of 3% PCN (MC) coating was higher than all the formulations. These PCN (MC) coatings may provide corrosion protection for C-steel pipes in many industrial applications. Full article

This study aimed to develop ketorolac microparticles stabilized by hyaluronic acid based on poly(lactide-co-glycolide) (PLGA), poly(lactide) (PLA), and their blend for further application in osteoarthritis. The polymer blend may provide tailored drug release and improved physicochemical characteristics. The microparticles were prepared by water-in-oil-in-water (w/o/w) double emulsion solvent evaporation using two emulsification techniques, probe sonication (PS) and high-speed stirring (HSS), to obtain the microparticles in different size ranges. The results revealed that the polymer composition and emulsification technique influenced the ketorolac microparticle characteristics. The PS technique provided significantly at least 20 times smaller average size (1.3–2.2 µm) and broader size distribution (1.5–8.5) than HSS (45.5–67.4 µm and 1.0–1.4, respectively). The encapsulation efficiency was influenced by the polymer composition and the emulsification technique, especially in the PLA microparticles. The DSC and XRD results suggested that the drug was compatible with and molecularly dissolved in the polymer matrix. Furthermore, most of the drug molecules existed in an amorphous form, and some in any crystalline form. All of the microparticles had biphasic drug release composed of the burst release within the first 2 h and the sustained release over 35 days. The obtained microparticles showed promise for further use in the treatment of osteoarthritis. Full article