Peptide-Based Hydrogel for Nanosystems Encapsulation: the Next Generation of Localized Delivery Systems for the Treatment of Intestinal Inflammations

Conventional therapies for inflammatory bowel diseases are mainly based on systemic treatments which cause side effects and toxicity over long-term administration. Nanoparticles appear as a valid alternative to allow a preferential accumulation in inflamed tissues following oral administration while reducing systemic drug exposure. To increase their residence time in the inflamed intestine, the nanoparticles are here associated with a hydrogel matrix. A bioadhesive peptide-based hydrogel is mixed with nanoemulsions, creating a hybrid lipid-polymer nanocomposite. Mucopenetrating nanoemulsions of 100 nm are embedded in a scaffold constituted of the self-assembling peptide hydrogel product PuraStat. The nanocomposite is fully characterized to study the impact of lipid particles in the hydrogel structure. Rheological measurements and circular dichroism analyses are performed to investigate the system's microstructure and physical properties. Biodistribution studies demonstrate that the nanocomposite acts as a depot in the stomach and facilitates the slow release of the nanoemulsions in the intestine. Efficacy studies upon oral administration of the drug-loaded system show the improvement of the disease score in a mouse model of intestinal inflammation.

The effect of electrostatic high pressure nebulization on the stability, activity and ex vivo distribution of ionic self-assembled nanomedicines

Pressurized intraperitoneal aerosol chemotherapy (PIPAC) is applied to treat unresectable peritoneal metastasis (PM), an advanced, end-stage disease with a poor prognosis. Electrostatic precipitation of the aerosol (ePIPAC) is aimed at improving the intraperitoneal (IP) drug distribution and tumor penetration. Also, the combination of nanoparticles (NPs) as drug delivery vehicles and IP aerosolization as administration method has been proposed as a promising tool to treat PM. There is currently limited knowledge on how electrostatic precipitation (ePIPAC) and high pressure nebulization (PIPAC) affects the performance of electrostatically formed complexes. Therefore, the stability, in vitro activity and ex vivo distribution and tissue penetration of negatively charged cisPt-pArg-HA NPs and positively charged siRNA-RNAiMAX NPs was evaluated following PIPAC and ePIPAC. Additionally, a multidirectional Medspray® nozzle was developed and compared with the currently used Capnopen® nozzle. For both NP types, PIPAC and ePIPAC did not negatively influence the in vitro activity, although limited aggregation of siRNA-RNAiMAX NPs was observed following nebulization with the Capnopen®. Importantly, ePIPAC was linked to a more uniform distribution and higher tissue penetration of the NPs aerosolized by both nozzles, independent on the NPs charge. Finally, compared to the Capnopen®, an increased NP deposition was observed at the top of the ex vivo model following aerosolization with the Medspray® nozzle, which indicates that this device possesses great potential for IP drug delivery purposes. STATEMENT OF SIGNIFICANCE: Aerosolized drug delivery in the peritoneal cavity holds great promise to treat peritoneal cancer. In addition, electrostatic precipitation of the aerosol to the peritoneal tissue is aimed at improving the drug distribution and tumor penetration. The combination of nanoparticles (NPs), which are nano-sized drug delivery vehicles, and aerosolization has been proposed as a promising tool to treat peritoneal cancer. However, there is currently limited knowledge on how electrostatic precipitation and aerosolization affect the performance of electrostatically formed NPs. Therefore, the stability, activity, distribution and penetration of negatively and positively charged NPs was evaluated after aerosolization and electrostatic precipitation. Additionally, to further optimize the local drug distribution, a multidirectional spray nozzle was developed and compared with the currently used nozzle.

Tackling TNF-α in autoinflammatory disorders and autoimmune diseases: From conventional to cutting edge in biologics and RNA- based nanomedicines

Autoinflammatory disorders and autoimmune diseases result from abnormal deviations of innate and adaptive immunity that heterogeneously affect organs and clinical phenotypes. Despite having etiologic and phenotypic differences, these two conditions share the onset of an aberrant inflammatory process. Targeting the main drivers controlling inflammation is useful to treat both autoimmune and autoinflammatory syndromes. TNF-α is a major player in the inflammatory immune response, and anti-TNF-α antibodies have been a revolutionary treatment in many autoimmune disorders. However, production difficulties and high development costs hinder their implementation, and accessibility to their use is still limited. Innovative strategies aimed at overcoming the limitations associated with anti-TNF-α antibodies are being explored, including RNA-based therapies. Here we summarize the central role of TNF-α in immune disorders and how anti-TNF-based immunotherapies changed the therapeutic landscape, albeit with important limitations related to side effects, tolerance, and resistance to therapies. We then outline how nanotechnology has provided the final momentum for the use of nucleic acids in the treatment of autoimmune and autoinflammatory diseases, with a focus on inflammatory bowel diseases (IBDs). The example of IBDs allows the evaluation and discussion of the nucleic acids-based treatments that have been developed, to identify the role that innovative approaches possess in view of the treatment of autoinflammatory disorders and autoimmune diseases.

Nanoemulsions Embedded in Alginate Beads as Bioadhesive Nanocomposites for Intestinal Delivery of the Anti-Inflammatory Drug Tofacitinib

Oral administration of nanoparticles (NPs) is a promising strategy to overcome solubility and stability issues of many active compounds. However, this route faces major obstacles related to the hostile gastrointestinal (GI) environment, which impairs the efficacy of orally administered nanomedicines. Here, we propose nanocomposites as a promising approach to increase the retention time of NPs in the intestinal tract by using bio- and mucoadhesive matrixes able to protect the cargo until it reaches the targeted area. A microfluidic-based approach has been applied for the production of tailored nanoemulsions (NEs) of about 110 nm, used for the encapsulation of small hydrophobic drugs such as the anti-inflammatory JAK-inhibitor tofacitinib. These NEs proved to be efficiently internalized into a mucus-secreting human intestinal monolayer of Caco-2/HT29-MTX cells and to deliver tofacitinib to subepithelial human THP-1 macrophage-like cells, reducing their inflammatory response. NEs were then successfully encapsulated into alginate hydrogel microbeads of around 300 μm, which were characterized by rheological experiments and dried to create a long-term stable system for pharmaceutical applications. Finally, ex vivo experiments on excised segments of rats' intestine proved the bioadhesive ability of NEs embedded in alginate hydrogels compared to free NEs, showing the advantage that this hybrid system can offer for the treatment of intestinal pathologies.

Hybrid core-shell particles for mRNA systemic delivery

mRNA based infectious disease vaccines have opened the venue for development of novel nucleic acids-based therapeutics. For all mRNA therapeutics dedicated delivery systems are required, where different functionalities and targeting abilities need to be optimized for the respective applications. One option for advanced formulations with tailored properties are lipid-polymer hybrid nanoparticles with complex nanostructure, which allow to combine features of several already well described nucleic acid delivery systems. Here, we explored hyaluronic acid (HA) as coating of liposome-mRNA complexes (LRCs) to investigate effects of the coating on surface charge, physicochemical characteristics and biological activity. HA was electrostatically attached to positively charged complexes, forming hybrid LRCs (HLRCs). At different N/P ratios, physico-chemical characterization of the two sets of particles showed similarity in size (around 200 nm) and mRNA binding abilities, while the presence of the HA shell conferred a negative surface charge to otherwise positive complexes. High transfection efficiency of LRCs and HLRCs in vitro has been obtained in THP-1 and human monocytes derived from PBMC, an interesting target cell population for cancer and immune related pathologies. In mice, quantitative biodistribution of radiolabeled LRC and HLRC particles, coupled with bioluminescence studies to detect the protein translation sites, hinted towards both particles' accumulation in the hepatic reticuloendothelial system (RES). mRNA translated proteins though was found mainly in the spleen, a major source for immune cells, with preference for expression in macrophages. The results showed that surface modifications of liposome-mRNA complexes can be used to fine-tune nanoparticle physico-chemical characteristics. This provides a tool for assembly of stable and optimized nanoparticles, which are prerequisite for future therapeutic interventions using mRNA-based nanomedicines.

Monomethyl Auristatin E Grafted-Liposomes to Target Prostate Tumor Cell Lines

Novel nanomedicines have been engineered to deliver molecules with therapeutic potentials, overcoming drawbacks such as poor solubility, toxicity or short half-life. Lipid-based carriers such as liposomes represent one of the most advanced classes of drug delivery systems. A Monomethyl Auristatin E (MMAE) warhead was grafted on a lipid derivative and integrated in fusogenic liposomes, following the model of antibody drug conjugates. By modulating the liposome composition, we designed a set of particles characterized by different membrane fluidities as a key parameter to obtain selective uptake from fibroblast or prostate tumor cells. Only the fluid liposomes made of palmitoyl-oleoyl-phosphatidylcholine and dioleoyl-phosphatidylethanolamine, integrating the MMAE-lipid derivative, showed an effect on prostate tumor PC-3 and LNCaP cell viability. On the other hand, they exhibited negligible effects on the fibroblast NIH-3T3 cells, which only interacted with rigid liposomes. Therefore, fluid liposomes grafted with MMAE represent an interesting example of drug carriers, as they can be easily engineered to promote liposome fusion with the target membrane and ensure drug selectivity.

Nanocomposite systems for precise oral delivery of drugs and biologics

Oral delivery is considered the favoured route of administration for both local and systemic delivery of active molecules. Formulation of drugs in conventional systems and nanoparticles has provided opportunities for targeting the gastrointestinal (GI) tract, increasing drug solubility and bioavailability. Despite the achievements of these delivery approaches, the development of a product with the ability of delivering drug molecules at a specific site and according to patients' needs remains a challenging endeavour. The complexity of the physicochemical properties of colloidal systems, their stability in different regions of the gastrointestinal tract, and interaction with the restrictive biological barriers hampered their success for oral precise medicine. To overcome these issues, nanoparticles have been combined with polymers to create hybrid nanosystems, namely nanocomposites. They offer enormous possibilities of structural and mechanical modifications to both nanoparticles and polymeric matrixes to generate systems with new properties, functions, and applications for oral delivery. In this review, nanocomposites' physicochemical and functional properties intended to target specific regions of the GI tract-oral cavity, stomach, small bowel, and colon-are analysed. In parallel, it is provided an insight in the nanocomposite solutions for oral delivery intended for systemic and local absorption, together with a focus on inflammatory bowel diseases (IBDs). Additional difficulties in managing IBD related to the alteration in the physiology of the intestine are described. Finally, future perspectives and opportunities for advancement in this field are discussed.

Physical PEGylation to Prevent Insulin Fibrillation

Insulin is one of the most marketed therapeutic proteins worldwide. However, its formulation suffers from fibrillation, which affects the long-term storage limiting the development of novel devices for sustained delivery including portable infusion devices. We have investigated the effect of physical PEGylation on structural and colloidal stability of insulin by using 2 PEGylating agents terminating with polycyclic hydrophobic moieties, cholane and cholesterol: mPEG_5kDa-cholane and mPEG_5kDa-cholesterol, respectively. Microcalorimetric analyses showed that mPEG_5kDa-cholane and mPEG_5kDa-cholesterol efficiently bind insulin with binding constants (Ka) of 3.98 10⁴ and 1.14 10⁵ M^-1, respectively. At room temperature, the 2 PEGylating agents yielded comparable structural stabilization of α-helix conformation and decreased dimerization of insulin. However, melting studies showed that mPEG_5kDa-cholesterol has superior stabilizing effect of the protein conformation than mPEG_5kDa-cholane. Furthermore, the fibrillation study showed that at a 1:1 and 1:5 insulin/polymer molar ratios, mPEG_5kDa-cholesterol delays insulin fibrillation 40% and 26% more efficiently, respectively, as compared to mPEG_5kDa-cholane which was confirmed by transmission electron microscopy imaging. Insulin was released from the mPEG_5kDa-cholane and mPEG_5kDa-cholesterol assemblies with comparable kinetic profiles. The physical PEGylation has a beneficial effect on the stabilization and shielding of the insulin structure into the monomeric form, which is not prone to fibrillation and aggregation.