Microparticles in the Development and Improvement of Pharmaceutical Formulations: An Analysis of In Vitro and In Vivo Studies

Functional interleukin-4 releasing microparticles impact THP-1 differentiated macrophage phenotype

Introduction

Macrophage cell therapies offer potential treatment in inflammatory diseases due to their ability to mobilize and stimulate their environment. However, successful treatment requires a pro-regenerative macrophage phenotype to be retained in vivo. Polymeric microparticles may provide a potential route to direct and sustain macrophage phenotype. Interleukin-4 (IL-4) is the most commonly used cytokine for in vitro modulation towards M2a macrophage phenotype. We designed IL-4 encapsulated microparticles to investigate the impact of drug release kinetics and developed a robust human peripheral blood monocyte cell (THP-1) in vitro assay to assess functional IL-4 release upon macrophage phenotype.

Methods

IL-4 was encapsulated with human serum albumin (HSA) in microparticles fabricated from a blend of PLGA and a PLGA-PEG-PLGA triblock copolymer. Functional release of IL-4 and HSA over different time periods was measured using ELISAs. THP-1 differentiated macrophages were cultured either in direct contact with microparticles or indirectly through transwells. The immunomodulatory impact of microparticles on THP-1 cells were measured using ELISA and qPCR.

Results and Discussion

IL-4 release kinetics fit with the first-order release kinetics model, indicating concentration dependent release. IL-4/HSA encapsulated microparticles modulated THP-1 differentiated macrophages towards pro-immunoregulatory subgroups. This strategy provides a novel approach in drug carrier development for in vitro assessments of macrophage phenotype to inform development of targeted therapies for inflammation and immune modulation.

Demystifying the Potential of Embelin-Loaded Nanoformulations: a Comprehensive Review

Phytoconstituent based therapies have the potential to reduce the adverse effects and enhance overall patient compliance for different diseased conditions. Embelin (EMB) is a natural compound extracted from Embelia ribes that has demonstrated high therapeutic potential, particularly as anti-inflammatory and anticancer therapeutic applications. However, its poor water solubility and low oral bioavailability limitations make it challenging to use in biomedical applications. Nanostructure-based novel formulations have shown the potential to improve physicochemical and biological characteristics of active pharmaceutical ingredients obtained from plants. Different nanoformulations that have been utilized to encapsulate/entrap EMB for various therapeutic applications are nanoliposomes, nanostructured lipid carriers, niosomes, polymeric nanoparticles, nanosuspensions, phytosomes, self nanoemulsifying drug delivery system, silver nanoparticles, microparticles, solid lipid nanoparticle, gold nanoparticles and nanomicelles. The common methods reported for the preparation of EMB nanoformulations are thin film hydration, nanoprecipitation, ethanol injection, emulsification followed by sonication. The size of nanoformulations ranged in between 50 and 345 nm. In this review, the mentioned EMB loaded nanocarriers are methodically discussed for size, shape, drug entrapment, zeta potential, in vitro release & permeation and in vivo studies. Potential of EMB with other drugs (dual drug approach) incorporated in nanocarriers are also discussed (physicochemical and preclinical characteristics). Patents related to EMB nanoformulations are also presented which showed the clinical translation of this bioactive for future utilization in different indications.

PVA-Stabilized and Coassembled Nano/Microparticles with High Payload of Dual Phytochemicals for Enhanced Antibacterial and Targeting Effect

The codelivery of multiple bioactive phytochemicals via nano/microparticles (NPs/MPs) represents a promising strategy for enhancing therapeutic efficacy. This study presents the development of novel poly(vinyl alcohol) (PVA)-stabilized hybrid particles designed for codelivery of palmatine hydrochloride (PAL) and glycyrrhizic acid (GL). Employing a straightforward coassembly method, we synthesized dual-drug particles achieving a high payload capacity of over 70%. The particles were characterized as uniform in size, within the nano/micron range, and exhibited a ζ-potential of -5.0 mV. The incorporation of PVA not only stabilized the particles but also refined the aggregation process, resulting in more uniform and finer particles approximately 1 μm in size. Spectral analysis and molecular dynamics simulations verified the presence of π-π stacking and hydrogen bonding between PAL and GL within the particles. In vitro antibacterial assays indicated that the hybrid particles had a lower minimum inhibitory concentration against Escherichia coli and Multidrug-Resistant Staphylococcus aureus than those of the pure drugs. In vivo biodistribution study in rats revealed that the PVA-stabilized particles revealed enhanced targeting to the liver, lung, and heart, demonstrating improved tissue selectivity compared with the solution group. In summary, the PVA-stabilized hybrid NPs/MPs represent an innovative and efficient platform for codelivery of multidrugs. These findings highlight the promise of coassembled particles for high loading, enhanced bioactivity, and targeted delivery, making them a strong candidate for future clinical applications.

Investigation of the Impact of Manufacturing Methods on Protein-Based Long-Acting Injectable Formulations: A Comparative Assessment for Microfluidics vs. Conventional Methods

Background/Objectives: Microparticle-based drug delivery systems offer several advantages for protein-based drug formulations, enhancing patient compliance and therapeutic efficiency through the sustained delivery of the active pharmaceutical ingredient. Over the past few decades, the microfluidics method has emerged as a continuous manufacturing process for preparing drug-encapsulating microparticles, mainly for small molecule drugs. However, comparative assessments for the conventional batch method vs. the microfluidics method for protein-based drug formulations have been lacking. The main objective of this study was to generate immunomodulatory protein drug-loaded injectable formulations using both conventional batch and microfluidics methods.

METHODS

Therefore, rhCCL22-loaded poly(lactic-co-glycolic) acid (PLGA) microparticles were prepared by conventional homogenization and microfluidics methods.

RESULTS

The resulting microparticles were analyzed comparatively, focusing on critical quality attributes such as microparticle size, size distribution, morphology, drug encapsulation efficiency, release kinetics, and batch-to-batch variations in relation to the manufacturing method. Our results demonstrated that the conventional method resulted in microparticles with denser surface porosity and wider size distribution as opposed to microparticles prepared by the microfluidics method, which could contribute to a significant difference in the drug-release kinetics. Additionally, our findings indicated minimal variation within batches for the microparticles prepared by the microfluidics method.

CONCLUSION

Overall, this study highlights the comparative assessment of several critical quality attributes and batch variations associated with the manufacturing methods of protein-loaded microparticles which is crucial for ensuring consistency in efficacy, regulatory compliance, and quality control in the drug formulation manufacturing process.

Application of Nanostructures in Biology and Medicine

At present, nanomaterials are used in a wide range of applications in all spheres of civil needs, including energy, medicine, and industry [...].

Inhalable drug-loaded silk fibroin carriers for pulmonary drug delivery

The design and development of engineered micro and nano-carriers offering superior therapeutic performance compared to traditional delivery forms, are crucial in pharmaceutical research. Aerosolization and inhalation of carriers with improved solubility/stability of insoluble drugs, has huge potential for targeted drug delivery (DD) in various pulmonary diseases. Indeed, dedicated carriers must meet specific dimensional rules for proper lung delivery. Particles between 2-10 μm in size are normally deposited in the tracheobronchial region, while particles of 0.5-2 μm may be properly deposited in the alveoli. In this work, we report the development of inhalable nanostructured carries made of a 'green' bio-inspired polymer from aqueous solutions, i.e. silk fibroin (SF), efficiently loaded with a hydrophobic drug, i.e. the thyroid hormone levothyroxine (L-T4), a drug for the treatment of idiopathic pulmonary fibrosis. The aim is to optimize a standard method for the synthesis of SF-based nanocarriers with controlled size and shape, where a fine control of their geometrical properties is aimed at efficiently controlling the pulmonary DD. L-T4 loaded SF particles were synthesized through a one-pot co-precipitation method. Optimized systems were determined by varying the chemo-physical parameters during the synthesis. Ethylenediaminetetraacetic acid (EDTA) was used to remove CaCO3 cores. The proposed synthesis routes have led to two SF structures, whose structural heterogeneity and nanostructured morphology have been demonstrated using fluorescence microscopy, DLS, SEM and EDX. Two systems with varying shape and size have been obtained: (i) a flat disk-like SF structure with an irregular surface and an in-plane length of about 1-2 μm; (ii) solid SF nanospheres, obtained using ethylene glycol as additive, showing two size populations (main diameters of 0.5 μm and 1.7 μm). Solid nanospherical systems, in particular, show a tendency to arrange into agglomerates that, when loosely bound into smaller particles, can facilitate the delivery at the alveoli. Both formulations exhibited similar drug loading efficiencies, evaluated by HPLC analysis. However, SF nanospheres showed greater in vitro drug release after 24 hours. The demonstrated control over the characteristics imparted to the proposed DD systems may be critical to select the most suitable size/shape to achieve high rates of delivery to the appropriate lung compartment.

Recent Advances in the Therapeutic Potential of Carotenoids in Preventing and Managing Metabolic Disorders

Carotenoids constitute compounds of significant biological interest due to their multiple biological activities, such as antimicrobial, anticancer, antiadipogenic, antidiabetic, and antioxidant properties. Metabolic syndrome (MetS) comprehends a series of metabolic abnormalities (e.g., hypertension, obesity, and atherogenic dyslipidemia) that can affect children, adolescents, and the elderly. The treatment of MetS involves numerous medications, which, despite their efficacy, pose challenges due to prolonged use, high costs, and various side effects. Carotenoids and their derivatives have been proposed as alternative treatments to MetS because they reduce serum triglyceride concentrations, promote insulin response, inhibit adipogenesis, and downregulate angiotensin-converting enzyme activity. However, carotenoids are notably sensitive to pH, light exposure, and temperature. This review addresses the activity of carotenoids such as lycopene, lutein, fucoxanthin, astaxanthin, crocin, and β-carotene towards MetS. It includes a discussion of sources, extraction methods, and characterization techniques for analyzing carotenoids. Encapsulation approaches are critically reviewed as alternatives to prevent degradation and improve the biological performance of carotenoids. A brief overview of the physiopathology and epidemiology of the diseases, including MetS, is also provided.

Drug Delivery Systems of Betulin and Its Derivatives: An Overview

Natural origin products are regarded as promising for the development of new therapeutic therapies with improved effectiveness, biocompatibility, reduced side effects, and low cost of production. Betulin (BE) is very promising due to its wide range of pharmacological activities, including its anticancer, antioxidant, and antimicrobial properties. However, despite advancements in the use of triterpenes for clinical purposes, there are still some obstacles that hinder their full potential, such as their hydrophobicity, low solubility, and poor bioavailability. To address these concerns, new BE derivatives have been synthesized. Moreover, drug delivery systems have emerged as a promising solution to overcome the barriers faced in the clinical application of natural products. The aim of this manuscript is to summarize the recent achievements in the field of delivery systems of BE and its derivatives. This review also presents the BE derivatives mostly considered for medical applications. The electronic databases of scientific publications were searched for the most interesting achievements in the last ten years. Thus far, it is mostly nanoparticles (NPs) that have been considered for the delivery of betulin and its derivatives, including organic NPs (e.g., micelles, conjugates, liposomes, cyclodextrins, protein NPs), inorganic NPs (carbon nanotubes, gold NPs, silver), and complex/hybrid and miscellaneous nanoparticulate systems. However, there are also examples of microparticles, gel-based systems, suspensions, emulsions, and scaffolds, which seem promising for the delivery of BE and its derivatives.

Preparation and Characterization of Polymeric Microparticles Based on Poly(ethylene brassylate-co-squaric Acid) Loaded with Norfloxacin

In recent years, increasing interest has been accorded to polyester-based polymer microstructures, driven by their promising potential as advanced drug delivery systems. This study presents the preparation and characterization of new polymeric microparticles based on poly(ethylene brassylate-co-squaric acid) loaded with norfloxacin, a broad-spectrum antibiotic. Polymacrolactone was synthesised in mild conditions through the emulsion polymerization of bio-based and renewable monomers, ethylene brassylate, and squaric acid. The microparticles were obtained using the precipitation technique and subsequently subjected to comprehensive characterization. The impact of the copolymer/drug ratio on various properties of the new system was systematically evaluated, confirming the structure of the copolymer and the encapsulation of norfloxacin. The microspheres are approximately spherical and predominantly homogeneously distributed. The average hydrodynamic diameter of the microparticles falls between 400 and 2000 nm, a decrease that is observed with the increase in norfloxacin content. All samples showed good encapsulation efficiency and drug loading capacity, with the highest values obtained for microparticles synthesised using an equal ratio of copolymer and drug. In vitro drug release results disclose that norfloxacin molecules are released in a sustained biphasic manner for up to 24 h. Antimicrobial activity was also studied, with samples showing very good activity against E. coli and moderate activity against S. aureus and E. faecalis. In addition, HDFA human fibroblast cell cultures demonstrated the cytocompatibility of the microparticles.

Revolutionizing Wound Healing: Exploring Scarless Solutions through Drug Delivery Innovations

Human skin is the largest organ and outermost surface of the human body, and due to the continuous exposure to various challenges, it is prone to develop injuries, customarily known as wounds. Although various tissue engineering strategies and bioactive wound matrices have been employed to speed up wound healing, scarring remains a significant challenge. The wound environment is harsh due to the presence of degradative enzymes and elevated pH levels, and the physiological processes involved in tissue regeneration operate on distinct time scales. Therefore, there is a need for effective drug delivery systems (DDSs) to address these issues. The objective of this review is to provide a comprehensive exposition of the mechanisms underlying the skin healing process, the factors and materials used in engineering DDSs, and the different DDSs used in wound care. Furthermore, this investigation will delve into the examination of emergent technologies and potential avenues for enhancing the efficacy of wound care devices.

Context-dependent role of SIRT3 in cancer

Sirtuin 3 (SIRT3), an NAD+-dependent deacetylase, plays a key role in the modulation of metabolic reprogramming and regulation of cell death, as well as in shaping tumor phenotypes. Owing to its critical role in determining tumor-type specificity or the direction of tumor evolution, the development of small-molecule modulators of SIRT3, including inhibitors and activators, is of significant interest. In this review, we discuss recent studies on the oncogenic or tumor-suppressive functions of SIRT3, evaluate advances in SIRT3-targeted drug discovery, and present potential avenues for the design of small-molecule modulators of SIRT3 for cancer therapy.

Immunological Regulation of Gut-Tropic Immune Cells by Extracellular Vesicles

The remarkable diversity of lymphocytes, essential components of the immune system, serves as an ingenious mechanism for maximizing the efficient utilization of limited host defense resources. While cell adhesion molecules, notably in gut-tropic T cells, play a central role in this mechanism, the counterbalancing molecular details have remained elusive. Conversely, we've uncovered the molecular pathways enabling extracellular vesicles secreted by lymphocytes to reach the gut's mucosal tissues, facilitating immunological regulation. This discovery sheds light on immune fine-tuning, offering insights into immune regulation mechanisms.

The Effect of Polymer Blends on the In Vitro Release/Degradation and Pharmacokinetics of Moxidectin-Loaded PLGA Microspheres

To investigate the effect of polymer blends on the in vitro release/degradation and pharmacokinetics of moxidectin-loaded PLGA microspheres (MOX-MS), four formulations (F1, F2, F3 and F4) were prepared using the O/W emulsion solvent evaporation method by blending high (75/25, 75 kDa) and low (50/50, 23 kDa) molecular weight PLGA with different ratios. The addition of low-molecular-weight PLGA did not change the release mechanism of microspheres, but sped up the drug release of microspheres and drastically shortened the lag phase. The in vitro degradation results show that the release of microspheres consisted of a combination of pore diffusion and erosion, and especially autocatalysis played an important role in this process. Furthermore, an accelerated release method was also developed to reduce the period for drug release testing within one month. The pharmacokinetic results demonstrated that MOX-MS could be released for at least 60 days with only a slight blood drug concentration fluctuation. In particular, F3 displayed the highest AUC and plasma concentration (AUC0-t = 596.53 ng/mL·d, Cave (day 30-day 60) = 8.84 ng/mL), making it the optimal formulation. Overall, these results indicate that using polymer blends could easily adjust hydrophobic drug release from microspheres and notably reduce the lag phase of microspheres.