Development of orally administered insulin-loaded polymeric-oligonucleotide nanoparticles: statistical optimization and physicochemical characterization

Intranasal delivery of temozolomide and desloratadine for brain tumour therapy: A cellular study on nasal epithelial toxicity, transport, and permeability

BACKGROUND

The treatment of brain tumours, particularly glioblastoma (GBM), remains a significant challenge due to limited therapeutic options and the restrictive nature of the blood-brain barrier (BBB), which contributes to inadequate effective drug delivery. Temozolomide (TMZ), the first-line chemotherapeutic agent for GBM, offers only a modest survival benefit of 14.6 months and is associated with significant systemic side effects. Intranasal drug delivery has emerged as a promising non-invasive alternative, offering direct nose-to-brain (N2B) pathways to bypass the BBB. This method enables rapid and targeted drug transport while minimising systemic toxicity.

METHODS

This study investigates the potential of desloratadine (DL), a repurposed non-sedating second-generation antihistamine, to enhance the therapeutic profile of TMZ in a nasal epithelial barrier model, representing the initial point of contact for N2B drug delivery. Cellular studies were conducted to evaluate the cytotoxicity, half-maximal inhibitory concentration, combination index, epithelial integrity, and drug transport properties of TMZ and DL alone and in combination. Transepithelial electrical resistance (TEER) and permeability coefficient (Papp) assays assessed barrier integrity and drug transport across the nasal epithelial cells, while cytotoxicity studies confirmed selective targeting of nasal cells during intranasal administration without affecting bronchial cell viability.

RESULTS

DL demonstrated significant intracellular retention in nasal epithelial cells, while TMZ exhibited efficient transport across the nasal barrier with moderate cellular retention. The combination of TMZ and DL reduced cytotoxicity in nasal epithelial cells compared to TMZ alone, suggesting DL's protective role in mitigating TMZ-induced cytotoxic effects. TEER and Papp analyses confirmed that both agents preserved nasal epithelial integrity, supporting their compatibility with N2B delivery. The synergistic effects of the combination therapy indicate an enhanced therapeutic profile for TMZ, with reduced off-target toxicity.

CONCLUSION

This study highlights the potential of a TMZ-DL drug combination therapy as a novel delivery strategy for brain tumour treatment. DL not only mitigates TMZ-induced cytotoxicity but also preserves the structural and functional integrity of the nasal epithelial barrier, addressing a critical translational gap in non-invasive drug delivery for brain tumours. Future work should focus on optimising dosing regimens and validating these findings in advanced 3D nasal models to facilitate clinical translation of this innovative therapeutic approach.

Advances in inhaler therapy for asthma and chronic obstructive pulmonary disease: a comprehensive review of Fostair™ and Trimbow™

The management of asthma and chronic obstructive pulmonary disease (COPD) poses considerable challenges due to the intricate nature of these respiratory conditions. Fostair™ and Trimbow™, two pressurized metered dose inhalers, have emerged as noteworthy therapeutic options for treating both asthma and COPD. Fostair combines an inhaled corticosteroid, specifically beclometasone dipropionate, with a long-acting beta2-agonist, formoterol fumarate dihydrate, offering a dual-action approach to mitigate airway inflammation and bronchoconstriction. Conversely, Trimbow integrates a tri-particulate formulation consisting of beclometasone dipropionate, formoterol fumarate dihydrate, and glycopyrronium bromide, providing a comprehensive strategy to target the pathophysiology of COPD and asthma. Recent clinical trials have underscored Trimbow's superior efficacy compared with Fostair, particularly in terms of reducing exacerbation rates and enhancing lung function. However, despite their therapeutic promise, both inhalers encounter challenges, including limited generalizability of study findings and a disparity between in vitro and human trial results. This literature review offers an in-depth analysis of Fostair and Trimbow, delving into their mechanisms of action, clinical applications, and outcomes in human studies for asthma and COPD. Additionally, the review discusses the role of combination therapy in managing respiratory diseases and underscores the necessity for further research to address existing knowledge gaps and optimize therapeutic outcomes.

Insulin Delivery to the Brain via the Nasal Route: Unraveling the Potential for Alzheimer's Disease Therapy

This comprehensive review delves into the potential of intranasal insulin delivery for managing Alzheimer's Disease (AD) while exploring the connection between AD and diabetes mellitus (DM). Both conditions share features of insulin signalling dysregulation and oxidative stress that accelerate inflammatory response. Given the physiological barriers to brain drug delivery, including the blood-brain barrier, intranasal administration emerges as a non-invasive alternative. Notably, intranasal insulin has shown neuroprotective effects, impacting Aβ clearance, tau phosphorylation, and synaptic plasticity. In preclinical studies and clinical trials, intranasally administered insulin achieved rapid and extensive distribution throughout the brain, with optimal formulations exhibiting minimal systemic circulation. The detailed mechanism of insulin transport through the nose-to-brain pathway is elucidated in the review, emphasizing the role of olfactory and trigeminal nerves. Despite promising prospects, challenges in delivering protein drugs from the nasal cavity to the brain remain, including enzymes, tight junctions, mucociliary clearance, and precise drug deposition, which hinder its translation to clinical settings. The review encompasses a discussion of the strategies to enhance the intranasal delivery of therapeutic proteins, such as tight junction modulators, cell-penetrating peptides, and nano-drug carrier systems. Moreover, successful translation of nose-to-brain drug delivery necessitates a holistic understanding of drug transport mechanisms, brain anatomy, and nasal formulation optimization. To date, no intranasal insulin formulation has received regulatory approval for AD treatment. Future research should address challenges related to drug absorption, nasal deposition, and the long-term effects of intranasal insulin. In this context, the evaluation of administration devices for nose-to-brain drug delivery becomes crucial in ensuring precise drug deposition patterns and enhancing bioavailability.

An overview of in vitro and in vivo techniques for characterization of intranasal protein and peptide formulations for brain targeting

The surge in neurological disorders necessitates innovative strategies for delivering active pharmaceutical ingredients to the brain. The non-invasive intranasal route has emerged as a promising approach to optimize drug delivery to the central nervous system by circumventing the blood-brain barrier. While the intranasal approach offers numerous advantages, the lack of a standardized protocol for drug testing poses challenges to both in vitro and in vivo studies, limiting the accurate interpretation of nasal drug delivery and pharmacokinetic data. This review explores the in vitro experimental assays employed by the pharmaceutical industry to test intranasal formulation. The focus lies on understanding the diverse techniques used to characterize the intranasal delivery of drugs targeting the brain. Parameters such as drug release, droplet size measurement, plume geometry, deposition in the nasal cavity, aerodynamic performance and mucoadhesiveness are scrutinized for their role in evaluating the performance of nasal drug products. The review further discusses the methodology for in vivo characterization in detail, which is essential in evaluating and refining drug efficacy through the nose-to-brain pathway. Animal models are indispensable for pre-clinical drug testing, offering valuable insights into absorption efficacy and potential variables affecting formulation safety. The insights presented aim to guide future research in intranasal drug delivery for neurological disorders, ensuring more accurate predictions of therapeutic efficacy in clinical contexts.

Microfluidic-assisted preparation of PLGA nanoparticles loaded with insulin: a comparison with double emulsion solvent evaporation method

Poly lactic-co-glycolic acid (PLGA) is an ideal polymer for the delivery of small and macromolecule drugs. Conventional preparation methods of PLGA nanoparticles (NPs) result in poor control over NPs properties. In this research, a microfluidic mixer was designed to produce insulin-loaded PLGA NPs with tuned properties. Importantly; aggregation of the NPs through the mixer was diminished due to the coaxial mixing of the precursors. The micromixer allowed for the production of NPs with small size and narrow size distribution compared to the double emulsion solvent evaporation (DESE) method. Furthermore, encapsulation efficiency and loading capacity indicated a significant increase in optimized NPs produced through the microfluidic method in comparison to DESE method. NPs prepared by the microfluidic method were able to achieve a more reduction of trans-epithelial electrical resistance values in the Caco-2 cells compared to those developed by the DESE technique that leads to greater paracellular permeation. Compatibility and interaction between components were evaluated by differential scanning calorimetry and fourier transform infrared analysis. Also, the effect of NPs on cell toxicity was investigated using MTT test. Numerical simulations were conducted to analyze the effect of mixing patterns on the properties of the NPs. It was revealed that by decreasing flow rate ratio, i.e. flow rate of the organic phase to the flow rate of the aqueous phase, mixing of the two streams increases. As an alternative to the DESE method, high flexibility in modulating hydrodynamic conditions of the microfluidic mixer allowed for nanoassembly of NPs with superior insulin encapsulation at smaller particle sizes.

Fabricating Polymer/Surfactant/Cyclodextrin Hybrid Particles for Possible Nose-to-Brain Delivery of Ropinirole Hydrochloride: In Vitro and Ex Vivo Evaluation

Ropinirole is a non-ergolinic dopamine agonist used to manage Parkinson's disease and it is characterized by poor oral bioavailability. This study aimed to design and develop advanced drug delivery systems composed of poloxamer 407, a non-ionic surfactant (Tween 80), and cyclodextrins (methyl-β-CD or hydroxy-propyl-β-CD) for possible brain targeting of ropinirole after nasal administration for the treatment of Parkinson's disease. The hybrid systems were formed by the thin-film hydration method, followed by an extensive physicochemical and morphological characterization. The in vitro cytotoxicity of the systems on HEK293 cell lines was also tested. In vitro release and ex vivo mucosal permeation of ropinirole were assessed using Franz cells at 34 °C and with phosphate buffer solution at pH 5.6 in the donor compartment, simulating the conditions of the nasal cavity. The results indicated that the diffusion-controlled drug release exhibited a progressive increase throughout the experiment, while a proof-of-concept experiment on ex vivo permeation through rabbit nasal mucosa revealed a better performance of the prepared hybrid systems in comparison to ropinirole solution. The encouraging results in drug release and mucosal permeation indicate that these hybrid systems can serve as attractive platforms for effective and targeted nose-to-brain delivery of ropinirole with a possible application in Parkinson's disease. Further ex vivo and in vivo studies to support the results of the present work are ongoing.

Development of Statistically Optimized Piperine-Loaded Polymeric Nanoparticles for Breast Cancer: In Vitro Evaluation and Cell Culture Studies

Piperine (PPN) is a natural alkaloid derived from black pepper (Piper nigrum L.) and has garnered substantial attention for its potential in breast cancer therapy due to its diverse pharmacological properties. However, its highly lipophilic characteristics and poor dissolution in biological fluids limit its clinical application. Therefore, to overcome this limitation, we formulate and evaluate PPN-encapsulated polycaprolactone (PCL) nanoparticles (PPN-PCL-NPs). The nanoparticles were prepared by a single-step nanoprecipitation method and further optimized by a formulation design approach. The influence of selected independent variables PCL (X1), poloxamer 188 (P-188; X2), and stirring speed (SS; X3) were investigated on the particle size (PS), polydispersity index (PDI), and % encapsulation efficiency (EE). The selected optimized nanoparticles were further assessed for stability, in vitro release, and in vitro antibreast cancer activity in the MCF-7 cancer cell line. The PS, PDI, zeta potential, and % EE of the optimized PPN-PCL-NPs were observed to be 107.61 ± 5.28 nm, 0.136 ± 0.011, -20.42 ± 1.82 mV, and 79.53 ± 5.22%, respectively. The developed PPN-PCL-NPs were stable under different temperature conditions with insignificant changes in their pharmaceutical attributes. The optimized PPN-PCL-NPs showed a burst release for the first 6 h and later showed sustained release for 48 h. The PPN-PCL-NPs exhibit exceptional cytotoxic effects in MCF-7 breast tumor cells in comparison with the native PPN. Thus, the formulation of PPN-loaded PCL-NPs can be a promising approach for better therapeutic efficacy against breast cancer.

Chitosan Nanoparticles in Atherosclerosis-Development to Preclinical Testing

Chitosan is a natural biopolymer that is present in an abundant supply in sources such as crustacean shells, mushrooms, and insect exoskeletons. It can be used to make a variety of types of drug formulations and is generally safe to use in vivo; plus, it has inherent cholesterol-reducing properties. While an abundance of papers has tested this biopolymer in nanoparticles in cancer and diabetes research, there is a lag of usage, and hence the paucity of information, in the area of cardiovascular research, specifically in atherosclerosis, the topic of this review. This review highlights some of the deficiencies in this niche area of research, examines the range of chitosan nanoparticles that have been researched to date, and proposes several ways forward to advance this field. Nanoparticles used for both diagnostic and therapeutic purposes are reviewed, with a discussion on how these nanoparticles could be better researched in future and what lays ahead as the field potentially moves towards clinical trials in future.

Oligonucleotide Therapies in the Treatment of Arthritis: A Narrative Review

Osteoarthritis (OA) and rheumatoid arthritis (RA) are two of the most common chronic inflammatory joint diseases, for which there remains a great clinical need to develop safer and more efficacious pharmacological treatments. The pathology of both OA and RA involves multiple tissues within the joint, including the synovial joint lining and the bone, as well as the articular cartilage in OA. In this review, we discuss the potential for the development of oligonucleotide therapies for these disorders by examining the evidence that oligonucleotides can modulate the key cellular pathways that drive the pathology of the inflammatory diseased joint pathology, as well as evidence in preclinical in vivo models that oligonucleotides can modify disease progression.

β-Cyclodextrin-containing chitosan-oligonucleotide nanoparticles improve insulin bioactivity, gut cellular permeation and glucose consumption

OBJECTIVES

The main objective of the present study was to develop a nanoparticulate drug delivery system that can protect insulin against harsh conditions in the gastrointestinal (GI) tract. The effects of the following employed techniques, including lyophilisation, cross-linking and nanoencapsulation, on the physicochemical properties of the formulation were investigated.

METHODS

We herein developed a nanocarrier via ionotropic gelation by using positively charged chitosan and negatively charged Dz13Scr. The lyophilised nanoparticles with optimal concentrations of tripolyphosphate (cross-linking agent) and β-cyclodextrin (stabilising agent) were characterised by using physical and cellular assays.

KEY FINDINGS

The addition of cryoprotectants (1% sucrose) in lyophilisation improved the stability of nanoparticles, enhanced the encapsulation efficiency, and ameliorated the pre-mature release of insulin at acidic pH. The developed lyophilised nanoparticles did not display any cytotoxic effects in C2C12 and HT-29 cells. Glucose consumption assays showed that the bioactivity of entrapped insulin was maintained post-incubation in the enzymatic medium.

CONCLUSIONS

Freeze-drying with appropriate cryoprotectant could conserve the physiochemical properties of the nanoparticles. The bioactivity of the entrapped insulin was maintained. The prepared nanoparticles could facilitate the permeation of insulin across the GI cell line.

Fabrication techniques for the preparation of orally administered insulin nanoparticles

The development of orally administered protein drugs is challenging due to their intrinsic unfavourable features, including large molecular size and poor chemical stability, both of which limit gastrointestinal (GI) absorption efficiency. Nanoparticles can overcome the GI barriers effectively and improve the oral bioavailability of proteins in the GI tract. They possess large surface area to volume ratio, and can facilitate the GI absorption of nanoparticles via the paracellular and transcellular routes. Nanoparticles can be prepared by various fabrication techniques that can encapsulate the fragile therapeutic proteins via hydrophobic bonding and electrostatic interaction. A desirable technique should involve minimal harsh conditions and encapsulate therapeutic proteins with preserved functionalities. The current review examines the characteristics of each preparation technique, and illustrates the examples of insulin-loaded nanoparticles that have been developed in each fabrication method. The following techniques, which include nanoprecipitation, hydrophobic conjugation, flash nanocomplexation, double emulsion, ionotropic gelation, and layer-by-layer adsorption, have been used to formulate ligand-modified nanoparticles for targeted delivery of insulin. Other techniques, including reduction, complex coacervation (polyelectrolyte complexation), hydrophobic ion pairing and emulsion solvent diffusion method, and sol-gel technology, were also discussed in the latter part of the review due to their extensive use in fabrication of insulin nanoparticles. This review also discusses the strategies that have been utilised during the formulation process to improve the stability and bioactivity of therapeutic proteins.

C2C12 cell model: its role in understanding of insulin resistance at the molecular level and pharmaceutical development at the preclinical stage

OBJECTIVES

The myoblast cell line, C2C12, has been utilised extensively in vitro as an examination model in understanding metabolic disease progression. Although it is indispensable in both preclinical and pharmaceutical research, a comprehensive review of its use in the investigation of insulin resistance progression and pharmaceutical development is not available.

KEY FINDINGS

C2C12 is a well-documented model, which can facilitate our understanding in glucose metabolism, insulin signalling mechanism, insulin resistance, oxidative stress, reactive oxygen species and glucose transporters at cellular and molecular levels. With the aid of the C2C12 model, recent studies revealed that insulin resistance has close relationship with various metabolic diseases in terms of disease progression, pathogenesis and therapeutic management. A holistic, safe and effective disease management is highly of interest. Therefore, significant efforts have been paid to explore novel drug compounds and natural herbs that can elicit therapeutic effects in the targeted sites at both cellular (e.g. mitochondria, glucose transporter) and molecular level (e.g. genes, signalling pathway).

SUMMARY

The use of C2C12 myoblast cell line is meaningful in pharmaceutical and biomedical research due to their expression of GLUT-4 and other features that are representative to human skeletal muscle cells. With the use of the C2C12 cell model, the impact of drug delivery systems (nanoparticles and quantum dots) on skeletal muscle, as well as the relationship between exercise, pancreatic β-cells and endothelial cells, was discovered.