Characterization of oat beta-glucan and coenzyme Q10-loaded beta-glucan powders generated by the pressurized gas-expanded liquid (PGX) technology

β-1,3 Glucan Microparticles & Nanoparticles: Fabrication Methods & Applications in Immunomodulation & Targeted Drug Delivery

Innate immune cells such as macrophages and dendritic cells play major roles in the progression of many cancerous, fibrotic, and autoimmune diseases, often due to environmental cues that skew these cells toward a phenotype that progresses or exacerbates the disease state. As such, a growing focus in treating such diseases is placed on exploiting the high plasticity of these cells to modify or reverse their pro-disease phenotypes using immunomodulatory materials. β-1,3 glucans are one such type of material that has exhibited diverse immunomodulatory effects on immune cells, including the mitigation or reversal of the adverse effects of dysregulated immune cells. In this review, we outline various fabrication techniques to produce β-1,3 glucan-derived microparticles and nanoparticles and discuss the diverse particle properties that can be obtained by tuning glucan chemistry, fabrication method, and formulation components. Furthermore, the immunomodulatory applications of β-1,3 glucan particles are highlighted with a focus on immune cell targeting, modulation, and the delivery of small molecule and macromolecular therapeutics.

Pharmaceutical Applications of Supercritical Fluid Extraction of Emulsions for Micro-/Nanoparticle Formation

Micro-/nanoparticle formulations containing drugs with or without various biocompatible excipients are widely used in the pharmaceutical field to improve the physicochemical and clinical properties of the final drug product. Among the various micro-/nanoparticle production technologies, emulsion-based particle formation is the most widely used because of its unique advantages such as uniform generation of spherical small particles and higher encapsulation efficiency (EE). For this emulsion-based micro-/nanoparticle technology, one of the most important factors is the extraction efficiency associated with the fast removal of the organic solvent. In consideration of this, a technology called supercritical fluid extraction of emulsions (SFEE) that uses the unique mass transfer mechanism and solvent power of a supercritical fluid (SCF) has been proposed to overcome the shortcomings of several conventional technologies such as solvent evaporation, extraction, and spray drying. This review article presents the main aspects of SFEE technology for the preparation of micro-/nanoparticles by focusing on its pharmaceutical applications, which have been organized and classified according to several types of drug delivery systems and active pharmaceutical ingredients. It was definitely confirmed that SFEE can be applied in a variety of drugs from water-soluble to poorly water-soluble. In addition, it has advantages such as low organic solvent residual, high EE, desirable release control, better particle size control, and agglomeration prevention through efficient and fast solvent removal compared to conventional micro-/nanoparticle technologies. Therefore, this review will be a good resource for determining the applicability of SFEE to obtain better pharmaceutical quality when researchers in related fields want to select a suitable manufacturing process for preparing desired micro-/nanoparticle drug delivery systems containing their active material.

Novel Technologies Based on Supercritical Fluids for the Encapsulation of Food Grade Bioactive Compounds

In recent years, the demand for nutritive, functional and healthy foods has increased. This trend has induced the food industry to investigate novel technologies able to produce ingredients with enhanced functional and physicochemical properties. Among these technologies, one of the most promising is the encapsulation based on supercritical fluids. Thanks to the inherent absence of organic solvent, the low temperature of the process to reach a supercritical state and the capacity to dissolve lipid soluble bioactives, the encapsulation with supercritical carbon dioxide represents a green technology to produce several functional ingredients, with enhanced stability, high load and tailored protection from environmental factors. Furthermore, from the fine-tuning of the process parameters like temperature, pressure and flow rate, the resulting functional ingredient can be easily designed to tailor the controlled release of the bioactive, or to reach specific levels of taste, odor and color. Accordingly, the aim of the present review is to summarize the state of the art of the techniques based on supercritical carbon dioxide for the encapsulation of bioactive compounds of food interest. Pros and cons of such techniques will be highlighted, giving emphasis to their innovative aspects that could be of interest to the food industry.

Drug-impregnated, pressurized gas expanded liquid-processed alginate hydrogel scaffolds for accelerated burn wound healing

While the benefits of both hydrogels and drug delivery to enhance wound healing have been demonstrated, the highly hydrophilic nature of hydrogels creates challenges with respect to the effective loading and delivery of hydrophobic drugs beneficial to wound healing. Herein, we utilize pressurized gas expanded liquid (PGX) technology to produce very high surface area (~200 m²/g) alginate scaffolds and describe a method for loading the scaffolds with ibuprofen (via adsorptive precipitation) and crosslinking them (via calcium chelation) to create a hydrogel suitable for wound treatment and hydrophobic drug delivery. The high surface area of the PGX-processed alginate scaffold facilitates >8 wt% loading of ibuprofen into the scaffold and controlled in vitro ibuprofen release over 12-24 h. In vivo burn wound healing assays demonstrate significantly accelerated healing with ibuprofen-loaded PGX-alginate/calcium scaffolds relative to both hydrogel-only and untreated controls, demonstrating the combined benefits of ibuprofen delivery to suppress inflammation as well as the capacity of the PGX-alginate/calcium hydrogel to maintain wound hydration and facilitate continuous calcium release to the wound. The use of PGX technology to produce highly porous scaffolds with increased surface areas, followed by adsorptive precipitation of a hydrophobic drug onto the scaffolds, offers a highly scalable method of creating medicated wound dressings with high drug loadings. STATEMENT OF SIGNIFICANCE: While medicated hydrogel-based wound dressings offer clear advantages in accelerating wound healing, the inherent incompatibility between conventional hydrogels and many poorly water-soluble drugs of relevance in wound healing remains a challenge. Herein, we leveraged supercritical fluids-based strategies to both process and subsequently impregnate alginate, followed by post-crosslinking to form a hydrogel, to create a very high surface area alginate hydrogel scaffold loaded with high hydrophobic drug contents (here, >8 wt% ibuprofen) without the need for any pore-forming additives. The impregnated scaffolds significantly accelerated burn wound healing while also promoting regeneration of the native skin morphology. We anticipate this approach can be leveraged to load clinically-relevant and highly bioavailable dosages of hydrophobic drugs in hydrogels for a broad range of potential applications.

Nile Red-Poly(Methyl Methacrylate)/Silica Nanocomposite Particles Increase the Sensitivity of Cervical Cancer Cells to Tamoxifen

Tamoxifen (TAM) is a hormonal drug and is mainly used as an anti-estrogen in breast cancer patients. TAM binds to estrogen receptors (ERs), resulting in inhibition of estrogen signaling pathways and thus, a downregulation of cell proliferation. Cancer cells with negative or low ER expression will not uptake TAM and will show low response. Poly (methyl methacrylate) (PMMA) nanoparticles were prepared using surfactant-free emulsion polymerization, then were loaded with Nile red (NR), which resulted in PMMA-NR. To enhance TAM delivery to cervical cancer cells (HELA), which is considered ER-negative, we loaded TAM and polymethyl methacrylate nanoparticles-Nile-red into silica (PMMA-NR-Si-TAM). The uptake and intracellular distribution were visualized by confocal laser scanning microscopy, and the in vitro cytotoxic activity was evaluated by MTT (3-(4,5-Dimethylthiazol-2-yl)-2,5-Diphenyltetrazolium Bromide) assay using HELA and non-tumorigenic cell line HFF-1. The sensitivity of HELA (LC50: 207.31 µg/mL) and HFF-1 (LC50: 234.08 µg/mL) to free TAM was very low. However, after the encapsulation of TAM with PMMA-NR, the sensitivity significantly increased HELA (LC50: 71.83 µg/mL) and HFF-1 (LC50: 37.36 µg/mL). This indicates that TAM can be used for the treatment of ER-negative cervical cancer once conjugated to PMMA-NR nanoparticles. In addition, the PMMA-NR formulation appears to be highly suitable for cancer imaging and drug delivery.