Liposomes for Targeting RNA Interference-Based Therapy in Inflammatory Bowel Diseases

The discovery of RNA interference (RNAi) in mammalian cells in 2001 opened up a new class of candidate therapeutics for hard-to-cure diseases like inflammatory bowel diseases. The main challenge for the development of RNAi-based therapeutics is the efficient and safe delivery of RNAi since the RNAi machinery is housed in the cytoplasm. Among the various approaches to active targeting, liposome-based delivery systems are innovative and promising systems to transport and control RNAi molecules release and overcome some of their limitations. Many RNAis in lipid formulations have progressed through various stages of clinical trials, with the measurable improvements in patients and no side effects. For colon targeting, liposomes can be manipulated by different methods. This chapter discusses the progress in delivering RNAi molecules to the colon using liposomes

Potential Toxicity of Nanoparticles for the Oral Delivery of Therapeutics

Nanoparticles (NPs) offer a promising solution for orally delivering therapeutic substances due to their capability to surpass traditional drug delivery system (DDS) limitations like low solubility, bioavailability, and stability. However, the possible toxic effects of using NPs for oral therapeutic delivery raise significant concerns, as they might interact with biological systems unexpectedly. This chapter aims to comprehensively understand the potential toxicity of NPs employed in oral therapeutic delivery. Factors such as size, surface area, surface charge, and surface chemistry of NPs can impact their toxicity levels. Both in vitro and in vivo models have been utilised to evaluate NPs toxicity, with in vivo models being more suitable for anticipating human toxicity. The possible toxic consequences of different NPs varieties, including polymer, lipid, and metal NPs, have been documented. Ultimately, grasping the potential toxicity of NPs in oral therapeutic delivery is essential for creating safe and effective DDS

In vivo and in vitro biocompatible alginate film crosslinked with Ca2+ and Co2+ manifests antiviral, antibacterial and anticancer activity

Alginate crosslinked with calcium cations is a promising hydrogel for biomedical applications as it is non-toxic, has suitable mechanical properties and is insoluble in water. Cobalt has been shown to possess antibacterial capacity against Gram-positive and Gram-negative bacteria, and has an angiogenesis effect. In this study, alginate films were crosslinked with Ca2+ and Co2+ ions to explore their biological properties in terms of antiviral capacity, antibacterial properties, anticancer activity and their toxicity. The results show that the hydrogel with a very small amount of cobalt was biocompatible in vivo using the Caenorhabditis elegans model and in vitro on human keratinocyte cells and it also exhibited antibacterial activity against the life-threatening methicillinresistant Staphylococcus aureus. Furthermore, this hydrogel showed antiviral activity against a surrogate of SARSCoV-2 and anticancer properties against melanoma and colon cancer cells, which render it a promising material for biomedical applications such as wound healing and tissue engineering. Water sorption experiments, Fourier transform infrared spectroscopy, electron microscopy with Energy Dispersive X-ray Spectrometry and degradation analysis in acid aqueous medium were performed to complete the characterization of these new materials.The authors would like to express their gratitude to the Fundacion ´ Universidad Catolica ´ de Valencia San Vicente Martir ´ and to the Spanish Ministry of Science and Innovation for their financial support through Grant 2020-231-006UCV and PID2020-119333RB-I00 / AEI / 10.13039/501100011033, respectively.TheCIBER-BBNinitiativeis funded by the VI National R&D&I Plan 2008 − 2011, Iniciativa Ingenio 2010, Consolider Program.CIBER actions are financed by the Instituto de Salud CarlosIII with assistance from the European Regional Development.Funding support also from Researchers Supporting Project number (RSP-2023R782), King Saud University, Riyadh, Saudi ArabiaBiotecnologí

In Vitro Characterization of Inhalable Cationic Hybrid Nanoparticles as Potential Vaccine Carriers

In this study, PGA-co-PDL nanoparticles (NPs) encapsulating model antigen, bovine serum albumin (BSA), were prepared via double emulsion solvent evaporation. In addition, chitosan hydrochloride (CHL) was incorporated into the external phase of the emulsion solvent method, which resulted in surface adsorption onto the NPs to form hybrid cationic CHL NPs. The BSA encapsulated CHL NPs were encompassed into nanocomposite microcarriers (NCMPs) composed of l-leucine to produce CHL NPs/NCMPs via spray drying. The CHL NPs/NCMPs were investigated for in vitro aerosolization, release study, cell viability and uptake, and stability of protein structure. Hybrid cationic CHL NPs (CHL: 10 mg/mL) of particle size (480.2 ± 32.2 nm), charge (+14.2 ± 0.72 mV), and BSA loading (7.28 ± 1.3 µg/mg) were produced. The adsorption pattern was determined to follow the Freundlich model. Aerosolization of CHL NPs/NCMPs indicated fine particle fraction (FPF: 46.79 ± 11.21%) and mass median aerodynamic diameter (MMAD: 1.49 ± 0.29 µm). The BSA α-helical structure was maintained, after release from the CHL NPs/NCMPs, as indicated by circular dichroism. Furthermore, dendritic cells (DCs) and A549 cells showed good viability (≥70% at 2.5 mg/mL after 4–24 h exposure, respectively). Confocal microscopy and flow cytometry data showed hybrid cationic CHL NPs were successfully taken up by DCs within 1 h of incubation. The upregulation of CD40, CD86, and MHC-II cell surface markers indicated that the DCs were successfully activated by the hybrid cationic CHL NPs. These results suggest that the CHL NPs/NCMPs technology platform could potentially be used for the delivery of proteins to the lungs for immunostimulatory applications such as vaccines

Biocompatible Alginate Film Crosslinked with Ca2+ and Zn2+ Possesses Antibacterial, Antiviral, and Anticancer Activities

Alginate is a highly promising biopolymer due to its non-toxic and biodegradable properties. Alginate hydrogels are often fabricated by cross-linking sodium alginate with calcium cations and can be engineered with highly desirable enhanced physical and biological properties for biomedical applications. This study reports on the anticancer, antiviral, antibacterial, in vitro, and in vivo toxicity, water absorption, and compound release properties of an alginate hydrogel crosslinked with calcium and different amounts of zinc cations. The results showed that the calcium alginate hydrogel film crosslinked with the highest amount of zinc showed similar water sorption properties to those of calcium alginate and released a suitable amount of zinc to provide anticancer activity against melanoma and colon cancer cells and has antibacterial properties against methicillin-resistant and antiviral activity against enveloped and non-enveloped viruses. This film is non-toxic in both in vitro in keratinocyte HaCaT cells and in vivo in the model, which renders it especially promising for biomedical applications

Engineering hydrophobically modified chitosan for enhancing the dispersion of respirable microparticles of levofloxacin

The potential of amphiphilic chitosan formed by grafting octanoyl chains on the chitosan backbone for pulmonary delivery of levofloxacin has been studied. The success of polymer synthesis was confirmed using FT-IR and NMR, whilst antimicrobial activity was assessed against Pseudomonas aeruginosa. Highly dispersible dry powders for delivery as aerosols were prepared with different amounts of chitosan and octanoyl chitosan to study the effect of hydrophobic modification and varying concentration of polymer on aerosolization of drug. Powders were prepared by spray-drying from an aqueous solution containing levofloxacin and chitosan/amphiphilic octanoyl chitosan. L-leucine was also used to assess its effect on aerosolization. Following spray-drying, the resultant powders were characterized using scanning electron microscopy, laser diffraction, dynamic light scattering, HPLC, differential scanning calorimetry, thermogravimetric analysis and X-ray powder diffraction. The in vitro aerosolization profile was determined using a Next Generation Impactor, whilst in vitro antimicrobial assessment was performed using MIC assay. Microparticles of chitosan have the property of mucoadhesion leading to potential increased residence time in the pulmonary mucus, making it important to test the toxicity of these formulations. In-vitro cytotoxicity evaluation using MTT assay was performed on A549 cell line to determine the toxicity of formulations and hence feasibility of use. The MTT assay confirmed that the polymers and the formulations were non-cytotoxic. Hydrophobically modifying chitosan showed significantly lower MIC (4-fold) than the commercial chitosan against P. aeruginosa. The powders generated were of suitable aerodynamic size for inhalation having a mass median aerodynamic diameter less than 4.5 lm for formulations containing octanoyl chitosan. These highly dispersible powders have minimal moisture adsorption and hence an emitted dose of more than 90% and a fine particle fraction (FPF) of 52%. Powders with non-modified chitosan showed lower dispersibility, with an emitted dose of 72% and FPF of 20%, as a result of high moisture adsorption onto the chitosan matrix leading to cohesiveness and subsequently decreased dispersibility

Pulmonary Delivery of Proteins Using Nanocomposite Microcarriers.

In this study, Taguchi design was used to determine optimal parameters for the preparation of bovine serum albumin (BSA)-loaded nanoparticles (NPs) using a biodegradable polymer poly(glycerol adipate-co-ω-pentadecalactone) (PGA-co-PDL). NPs were prepared, using BSA as a model protein, by the double emulsion evaporation process followed by spray-drying from leucine to form nanocomposite microparticles (NCMPs). The effect of various parameters on NP size and BSA loading were investigated and dendritic cell (DC) uptake and toxicity. NCMPs were examined for their morphology, yield, aerosolisation, in vitro release behaviour and BSA structure. NP size was mainly affected by the polymer mass used and a small particle size ≤500 nm was achieved. High BSA (43.67 ± 2.3 μg/mg) loading was influenced by BSA concentration. The spray-drying process produced NCMPs (50% yield) with a porous corrugated surface, aerodynamic diameter 1.46 ± 141 μm, fine particle dose 45.0 ± 4.7 μg and fine particle fraction 78.57 ± 0.1%, and a cumulative BSA release of 38.77 ± 3.0% after 48 h. The primary and secondary structures were maintained as shown by sodium dodecyl sulphate poly (acrylamide) gel electrophoresis and circular dichroism. Effective uptake of NPs was seen in DCs with >85% cell viability at 5 mg/mL concentration after 4 h. These results indicate the optimal process parameters for the preparation of protein-loaded PGA-co-PDL NCMPs suitable for inhalation. © 2015 Wiley Periodicals, Inc. and the American Pharmacists Association J Pharm Sci

In Vitro Characterization of Inhalable Cationic Hybrid Nanoparticles as Potential Vaccine Carriers

In this study, PGA-co-PDL nanoparticles (NPs) encapsulating model antigen, bovine serum albumin (BSA), were prepared via double emulsion solvent evaporation. In addition, chitosan hydrochloride (CHL) was incorporated into the external phase of the emulsion solvent method, which resulted in surface adsorption onto the NPs to form hybrid cationic CHL NPs. The BSA encapsulated CHL NPs were encompassed into nanocomposite microcarriers (NCMPs) composed of l-leucine to produce CHL NPs/NCMPs via spray drying. The CHL NPs/NCMPs were investigated for in vitro aerosolization, release study, cell viability and uptake, and stability of protein structure. Hybrid cationic CHL NPs (CHL: 10 mg/mL) of particle size (480.2 ± 32.2 nm), charge (+14.2 ± 0.72 mV), and BSA loading (7.28 ± 1.3 µg/mg) were produced. The adsorption pattern was determined to follow the Freundlich model. Aerosolization of CHL NPs/NCMPs indicated fine particle fraction (FPF: 46.79 ± 11.21%) and mass median aerodynamic diameter (MMAD: 1.49 ± 0.29 µm). The BSA α-helical structure was maintained, after release from the CHL NPs/NCMPs, as indicated by circular dichroism. Furthermore, dendritic cells (DCs) and A549 cells showed good viability (≥70% at 2.5 mg/mL after 4–24 h exposure, respectively). Confocal microscopy and flow cytometry data showed hybrid cationic CHL NPs were successfully taken up by DCs within 1 h of incubation. The upregulation of CD40, CD86, and MHC-II cell surface markers indicated that the DCs were successfully activated by the hybrid cationic CHL NPs. These results suggest that the CHL NPs/NCMPs technology platform could potentially be used for the delivery of proteins to the lungs for immunostimulatory applications such as vaccines

Lipid Nanoparticles as Delivery Systems for RNA-Based Vaccines

There has been increased interest in the development of RNA-based vaccines for protection against various infectious diseases and also for cancer immunotherapies. Rapid and cost-effective manufacturing methods in addition to potent immune responses observed in preclinical and clinical studies have made mRNA-based vaccines promising alternatives to conventional vaccine technologies. However, efficient delivery of these vaccines requires that the mRNA be protected against extracellular degradation. Lipid nanoparticles (LNPs) have been extensively studied as non-viral vectors for the delivery of mRNA to target cells because of their relatively easy and scalable manufacturing processes. This review highlights key advances in the development of LNPs and reviews the application of mRNA-based vaccines formulated in LNPs for use against infectious diseases and cancer