Search Results (9)

The assessment of ricinoleic acid (RA) incorporated into polymeric nanoparticles is a challenge that has not yet been explored. This bioactive compound, the main component of castor oil, has attracted attention in the pharmaceutical field for its valuable anti-inflammatory, antifungal, and antimicrobial properties. This work aims to develop a new and simple analytical method using high-performance liquid chromatography with diode-array detection (HPLC-DAD) for the identification and quantification of ricinoleic acid, with potential applicability in several other complex systems. The method was validated through analytical parameters, such as linearity, limit of detection and quantification, accuracy, precision, selectivity, and robustness. The physicochemical properties of the nanocapsules were characterized by dynamic light scattering (DLS) to determine their hydrodynamic mean diameter, polydispersity index (PDI), and zeta potential (ZP), via transmission electron microscopy (TEM) and quantifying the encapsulation efficiency. The proposed analytical method utilized a mobile phase consisting of a 65:35 ratio of acetonitrile to water, acidified with 1.5% phosphoric acid. It successfully depicted a symmetric peak of ricinoleic acid (retention time of 7.5 min) for both the standard and the RA present in the polymeric nanoparticles, enabling the quantification of the drug loaded into the nanocapsules. The nanocapsules containing ricinoleic acid (RA) exhibited an approximate size ranging from 309 nm to 441 nm, a PDI lower than 0.2, ζ values of approximately −30 mV, and high encapsulation efficiency (~99%). Overall, the developed HPLC-DAD procedure provides adequate confidence for the identification and quantification of ricinoleic acid in PLGA nanocapsules and other complex matrices. Full article

Gallic acid–Antarctic krill peptides (GA-AKP) nanocapsules (GA-AKP-Ns) were prepared using a dual delivery system with complex emulsion as the technical method, a high-pressure microjet as the technical means, polylactic acid–hydroxyacetic acid (PLGA) as the drug delivery vehicle, and GA-AKP as the raw material for delivery. This study aimed to investigate the effects of microjet treatment and the concentration of PLGA on the physicochemical properties and stability of the emulsion. Under optimal conditions, the physicochemical properties and hypoglycemic function of nano-microcapsules prepared after lyophilization by the solvent evaporation method were analyzed. Through the microjet treatment, the particle size of the emulsion was reduced, the stability of the emulsion was improved, and the encapsulation rate of GA-AKP was increased. The PLGA at low concentrations decreased the particle size of the emulsion, while PLGA at high concentrations enhanced the encapsulation efficiency of the emulsion. Additionally, favorable results were obtained for emulsion preparation through high-pressure microjet treatment. After three treatment cycles with a PLGA concentration of 20 mg/mL and a microjet pressure of 150 MPa (manometric pressure), the emulsion displayed the smallest particle size (285.1 ± 3.0 nm), the highest encapsulation rates of GA (71.5%) and AKP (85.2%), and optimal physical stability. GA-AKP was uniformly embedded in capsules, which can be slowly released in in vitro environments, and effectively inhibited α-amylase, α-glucosidase, and DPP-IV at different storage temperatures. This study demonstrated that PLGA as a carrier combined with microjet technology can produce excellent microcapsules, especially nano-microcapsules, and these microcapsules effectively improve the bioavailability and effectiveness of bioactive ingredients. Full article

Artificial cells have been extensively used in many fields, such as nanomedicine, biotherapy, blood substitutes, drug delivery, enzyme/gene therapy, cancer therapy, and the COVID-19 vaccine. The unique properties of superparamagnetic Fe₃O₄ nanoparticles have contributed to increased interest in using superparamagnetic artificial cells (PLGA-Fe₃O₄ micro/nanocapsules) for targeted therapy. In this review, the preparation methods of Fe₃O₄ NPs and superparamagnetic artificial cell PLGA-drug-Fe₃O₄ micro/nanocapsules are discussed. This review also focuses on the recent progress of superparamagnetic PLGA-drug-Fe₃O₄ micro/nanocapsules as targeted therapeutics. We shall concentrate on the use of superparamagnetic artificial cells in the form of PLGA-drug-Fe₃O₄ nanocapsules for magnetic hyperthermia/photothermal therapy and cancer therapies, including lung breast cancer and glioblastoma. Full article

Therapy for aggressive metastatic breast cancer remains a great challenge for modern biomedicine. Biocompatible polymer nanoparticles have been successfully used in clinic and are seen as a potential solution. Specifically, researchers are exploring the development of chemotherapeutic nanoagents targeting the membrane-associated receptors of cancer cells, such as HER2. However, there are no targeting nanomedications that have been approved for human cancer therapy. Novel strategies are being developed to alter the architecture of agents and optimize their systemic administration. Here, we describe a combination of these approaches, namely, the design of a targeted polymer nanocarrier and a method for its systemic delivery to the tumor site. Namely, PLGA nanocapsules loaded with a diagnostic dye, Nile Blue, and a chemotherapeutic compound, doxorubicin, are used for two-step targeted delivery using the concept of tumor pre-targeting through the barnase/barstar protein “bacterial superglue”. The first pre-targeting component consists of an anti-HER2 scaffold protein, DARPin9_29 fused with barstar, Bs-DARPin9_29, and the second component comprises chemotherapeutic PLGA nanocapsules conjugated to barnase, PLGA-Bn. The efficacy of this system was evaluated in vivo. To this aim, we developed an immunocompetent BALB/c mouse tumor model with a stable expression of human HER2 oncomarkers to test the potential of two-step delivery of oncotheranostic nano-PLGA. In vitro and ex vivo studies confirmed HER2 receptor stable expression in the tumor, making it a feasible tool for HER2-targeted drug evaluation. We demonstrated that two-step delivery was more effective than one-step delivery for both imaging and tumor therapy: two-step delivery had higher imaging capabilities than one-step and a tumor growth inhibition of 94.9% in comparison to 68.4% for the one-step strategy. The barnase*barstar protein pair has been proven to possess excellent biocompatibility, as evidenced by the successful completion of biosafety tests assessing immunogenicity and hemotoxicity. This renders the protein pair a highly versatile tool for pre-targeting tumors with various molecular profiles, thereby enabling the development of personalized medicine. Full article

Owing to their complicated pathophysiology, the treatment of skin diseases necessitates a complex approach. Conventional treatment using topical corticosteroids often results in low effectiveness and the incidence of local or even systemic side effects. Nanoformulation of potent anti-inflammatory drugs has been selected as an optimal strategy for enhanced topical delivery of corticosteroids. In order to assess the efficiency of various nanoformulations, we formulated hydrocortisone (HC) and hydrocortisone-17-butyrate (HCB) into three different systems: lipid nanocapsules (LNC), polymeric nanoparticles (PNP), and ethosomes (ETZ). The systems were characterized using dynamic light scattering for their particle size and uniformity and the morphology of nanoparticles was observed by transmission electron microscopy. The nanosystems were tested using ex vivo full thickness porcine and human skin for the delivery of HC and HCB. The skin penetration was observed by confocal microscopy of fluorescently labelled nanosystems. ETZ were proposed as the most effective delivery system for both transdermal and dermal drug targeting but were also found to have a profound effect on the skin barrier with limited restoration. LNC and PNP were found to have significant effects in the dermal delivery of the actives with only minimal transdermal penetration, especially in case of HCB administration. Full article

Nearly four million yearly deaths can be attributed to respiratory diseases, prompting a huge worldwide health emergency. Additionally, the COVID-19 pandemic’s death toll has surpassed six million, significantly increasing respiratory disease morbidity and mortality rates. Despite recent advances, it is still challenging for many drugs to be homogeneously distributed throughout the lungs, and specifically to reach the lower respiratory tract with an accurate sustained dose and minimal systemic side effects. Engineered nanocarriers can provide increased therapeutic efficacy while lessening potential biochemical adverse reactions. Poly(lactic-co-glycolic acid) (PLGA), a biodegradable polymer, has attracted significant interest as an inhalable drug delivery system. However, the influence of the nanocarrier surface charge and its intratracheal instillation has not been addressed so far. In this study, we fabricated red fluorescent PLGA nanocapsules (NCs)—Cy5/PLGA—with either positive (Cy5/PLGA+) or negative surface charge (Cy5/PLGA-). We report here on their excellent colloidal stability in culture and biological media, and after cryo-storage. Their lack of cytotoxicity in two relevant lung cell types, even for concentrations as high as 10 mg/mL, is also reported. More importantly, differences in the NCs’ cell uptake rates and internalization capacity were identified. The uptake of the anionic system was faster and in much higher amounts—10-fold and 2.5-fold in macrophages and epithelial alveolar cells, respectively. The in vivo study demonstrated that anionic PLGA NCs were retained in all lung lobules after 1 h of being intratracheally instilled, and were found to accumulate in lung macrophages after 24 h, making those nanocarriers especially suitable as a pulmonary immunomodulatory delivery system with a marked translational character. Full article

Background: the present work describes the preparation, characterization and optimization of eight types of PLGA-based nanosystems (nanospheres and nanocapsules) as innovative mucoadhesive drug delivery systems of lactoferrin, in order to achieve a preclinical consistent base as an alternative pharmacological treatment to different ocular syndromes and diseases. Methods: All different nanoparticles were prepared via two modified nanoprecipitation techniques, using a three-component mixture of drug/polymer/surfactant (Lf/PLGA/Poloxamer), as a way to overcome the inherent limitations of conventional PLGA NPs. These modified polymeric nanocarriers, intended for topical ophthalmic administration, were subjected to in vitro characterization, surface modification and in vitro and in vivo assessments. Results: An appropriate size range, uniform size distribution and negative ζ potential values were obtained for all types of formulations. Lactoferrin could be effectively included into all types of nanoparticles with appropriate encapsulation efficiency and loading capacity values. A greater, extended, and controlled delivery of Lf from the polymeric matrix was observed through the in vitro release studies. No instability or cytotoxicity was proved for all the formulations by means of organotypic models. Additionally, mucoadhesive in vitro and in vivo experiments show a significant increase in the residence time of the nanoparticles in the eye surface. Conclusions: all types of prepared PLGA nanoparticles might be a potential alternative for the topical ophthalmic administration of lactoferrin. Full article

Developing multifunctional and biocompatible drug delivery nanoplatforms that integrate high drug loads and multiple imaging modalities avoiding cross-interferences is extremely challenging. Here we report on the successful chemical reaction of the high quantum yield biodegradable and photoluminescent polyester (BPLP) with the poly(lactic-co-glycolic acid) (PLGA) polymer to fabricate biocompatible photoluminescent nanocapsules (NCs). Furthermore, we transform the PLGA-BPLP NCs into a magnetic resonance (MR)/photoluminescence dual-modal imaging theranostic platform by incorporating superparamagnetic iron oxide nanoparticles (SPIONs) into the polymeric shell. In vitro phantoms confirmed the excellent MRI-r₂ relaxivity values of the NCs whilst the cellular uptake of these NCs was clearly observed by fluorescence optical imaging. Besides, the NCs (mean size ~270 nm) were loaded with ~1 wt% of a model protein (BSA) and their PEGylation provided a more hydrophilic surface. The NCs show biocompatibility in vitro, as hCMEC/D3 endothelial cells viability was not affected for particle concentration up to 500 μg/mL. Interestingly, NCs decorated with SPIONs can be exploited for magnetic guiding and retention. Full article

The ability to form biofilms contributes significantly to the pathogenesis of many microbial infections, including a variety of ocular diseases often associated with the biofilm formation on foreign materials. Carvacrol (Car.) is an important component of essential oils and recently has attracted much attention pursuant to its ability to promote microbial biofilm disruption. In the present study Car. has been encapsulated in poly(DL-lactide-co-glycolide (PLGA) nanocapsules in order to obtain a suitable drug delivery system that could represent a starting point for developing new therapeutic strategies against biofilm-associated infections, such as improving the drug effect by associating an antimicrobial agent with a biofilm viscoelasticity modifier. Full article