Montmorillonite restricts free fatty acid liberation and alters self-assembled structures formed during in vitro lipid digestion

The global rise in obesity necessitates innovative weight loss strategies. Naturally occurring smectite clays, such as montmorillonite (MMT), offer promise due to their unique properties that interfere with free fatty acid (FFA) liberation, reducing systemic uptake. However, the mechanisms of MMT-FFA interactions and their implications for weight management are undefined. This study investigates these interactions by adding MMT (10 % w/w) to in vitro lipolysis media containing medium chain triglycerides (MCTs), and monitoring FFA liberation using pH-stat titration. Nanoparticle tracking analysis (NTA) and synchrotron-based small-angle X-ray scattering (sSAXS) observed time-dependent structural changes, while electron microscopy examined clay morphology during digestion. A 35 % reduction in FFA liberation occurred after 25 min of digestion with MCT + MMT, with digestion kinetics following a biphasic model driven by calcium soap formation. NTA revealed a 17-fold decrease in vesicular structures with MCT + MMT, and sSAXS highlighted a rapid lamellar phase evolution linked to calcium soap formation. This acceleration is attributed to MMT's adsorption to unionized FFAs via hydrogen bonding, supported by TEM images showing a decrease in d-spacing, indicating FFA intercalation is not the main adsorption mechanism. These findings highlight MMT's potential as a novel intervention for reducing dietary lipid absorption in obesity and metabolic diseases.

Contrasting the pharmacokinetic performance and gut microbiota effects of an amorphous solid dispersion and lipid nanoemulsion for a poorly water-soluble anti-psychotic

Increasing attention is being afforded to understanding the bidirectional relationship that exists between oral drugs and the gut microbiota. Often overlooked, however, is the impact that pharmaceutical excipients exert on the gut microbiota. Subsequently, in this study, we contrasted the pharmacokinetic performance and gut microbiota interactions between two commonly employed formulations for poorly soluble compounds, namely 1) an amorphous solid dispersion (ASD) stabilised by poly(vinyl pyrrolidone) K-30, and 2) a lipid nanoemulsion (LNE) comprised of medium chain glycerides and lecithin. The poorly soluble antipsychotic, lurasidone, was formulated with ASD and LNE due to its rate-limiting dissolution, poor oral bioavailability, and significant food effect. Both the ASD and LNE were shown to facilitate lurasidone supersaturation within in vitro dissolution studies simulating the gastrointestinal environment. This translated into profound improvements in oral pharmacokinetics in rats, with the ASD and LNE exerting comparable ∼ 2.5-fold improvements in lurasidone bioavailability, compared to the pure drug. The oral formulations imparted contrasting effects on the gut microbiota, with the LNE depleting the richness and abundance of the microbial ecosystem, as evidenced through reductions in alpha diversity (Chao1 index) and operational taxonomical units (OTUs). In contrast, the ASD exerted a 'gut neutral' effect, whereby a mild enrichment of alpha diversity and OTUs was observed. Importantly, this suggests that ASDs are effective solubility-enhancing formulations that can be used without comprising the integrity of the gut microbiota - an integral consideration in the treatment of mental health disorders, such as schizophrenia, due to the role of the gut microbiota in regulating mood and cognition.

A translational framework to DELIVER nanomedicines to the clinic

Nanomedicines have created a paradigm shift in healthcare. Yet fundamental barriers still exist that prevent or delay the clinical translation of nanomedicines. Critical hurdles inhibiting clinical success include poor understanding of nanomedicines' physicochemical properties, limited exposure in the cell or tissue of interest, poor reproducibility of preclinical outcomes in clinical trials, and biocompatibility concerns. Barriers that delay translation include industrial scale-up or scale-down and good manufacturing practices, funding and navigating the regulatory environment. Here we propose the DELIVER framework comprising the core principles to be realized during preclinical development to promote clinical investigation of nanomedicines. The proposed framework comes with design, experimental, manufacturing, preclinical, clinical, regulatory and business considerations, which we recommend investigators to carefully review during early-stage nanomedicine design and development to mitigate risk and enable timely clinical success. By reducing development time and clinical trial failure, it is envisaged that this framework will help accelerate the clinical translation and maximize the impact of nanomedicines.

The biomolecule corona mediates pulmonary delivery of nanomedicine

Pulmonary delivery of therapeutics (e.g., biologics, antibiotics, and chemotherapies) encapsulated in nanoparticles is desirable for the ability to provide a localised treatment, bypassing the harsh gastrointestinal environment. However, limited understanding of the biological fate of nanoparticles upon administration to the lungs hinders translation of pre-clinical investigations into viable therapies. A key knowledge gap is the impact of the pulmonary biomolecular corona on the functionality of nanoparticles. In this review, opportunities and challenges associated with pulmonary nanoparticle delivery are elucidated, highlighting the impact of the pulmonary biomolecular corona on immune recognition and nanoparticle internalisation in target cells. Recent investigations detailing the influence of proteins, lipids and mucin derived from pulmonary surfactants on nanoparticle behaviour are detailed. In addition, latest approaches in modulating plasma protein corona upon systemic delivery for biodistribution to the lungs are also discussed. Key examples of reengineering nanoparticle structure to mediate formation of biomolecule corona are provided. This review aims to provide a comprehensive understanding on biomolecular corona of nanoparticles for pulmonary delivery, while accentuating their significance for successful translation of newly investigated therapeutics.

The Gut Microbiome as a Catalyst and Emerging Therapeutic Target for Parkinson's Disease: A Comprehensive Update

Parkinson's Disease is the second most prevalent neurological disorder globally, and its cause is still largely unknown. Likewise, there is no cure, and existing treatments do little more than subdue symptoms before becoming ineffective. It is increasingly important to understand the factors contributing to Parkinson's Disease aetiology so that new and more effective pharmacotherapies can be established. In recent years, there has been an emergence of research linking gut dysbiosis to Parkinson's Disease via the gut-brain axis. Advancements in microbial profiling have led to characterisation of a Parkinson's-specific microbial signature, where novel treatments that leverage and correct gut dysbiosis are beginning to emerge for the safe and effective treatment of Parkinson's Disease. Preliminary clinical studies investigating microbiome-targeted therapeutics for Parkinson's Disease have revealed promising outcomes, and as such, the aim of this review is to provide a timely and comprehensive update of the most recent advances in this field. Faecal microbiota transplantation has emerged as a novel and potential frontrunner for microbial-based therapies due to their efficacy in alleviating Parkinson's Disease symptomology through modulation of the gut-brain axis. However, more rigorous clinical investigation, along with technological advancements in diagnostic and in vitro testing tools, are critically required to facilitate the widespread clinical translation of microbiome-targeting Parkinson's Disease therapeutics.

Updated perspectives on the contribution of the microbiome to the pathogenesis of mucositis using the MASCC/ISOO framework

Advances in the treatment of cancer have significantly improved mortality rates; however, this has come at a cost, with many treatments still limited by their toxic side effects. Mucositis in both the mouth and gastrointestinal tract is common following many anti-cancer agents, manifesting as ulcerative lesions and associated symptoms throughout the alimentary tract. The pathogenesis of mucositis was first defined in 2004 by Sonis, and almost 20 years on, the model continues to be updated reflecting ongoing research initiatives and more sophisticated analytical techniques. The most recent update, published by the Multinational Association for Supportive Care in Cancer and the International Society for Oral Oncology (MASCC/ISOO), highlights the numerous co-occurring events that underpin mucositis development. Most notably, a role for the ecosystem of microorganisms that reside throughout the alimentary tract (the oral and gut microbiota) was explored, building on initial concepts proposed by Sonis. However, many questions remain regarding the true causal contribution of the microbiota and associated metabolome. This review aims to provide an overview of this rapidly evolving area, synthesizing current evidence on the microbiota's contribution to mucositis development and progression, highlighting (i) components of the 5-phase model where the microbiome may be involved, (ii) methodological challenges that have hindered advances in this area, and (iii) opportunities for intervention.

The atypical antipsychotics lurasidone and olanzapine exert contrasting effects on the gut microbiome and metabolic function of rats

BACKGROUND AND PURPOSE

Antipsychotics such as olanzapine are associated with significant metabolic dysfunction, attributed to gut microbiome dysbiosis. A recent notion that most psychotropics are detrimental to the gut microbiome has arisen from consistent findings of metabolic adverse effects. However, unlike olanzapine, the metabolic effects of lurasidone are conflicting. Thus, this study investigates the contrasting effects of olanzapine and lurasidone on the gut microbiome to explore the hypothesis of 'gut neutrality' for lurasidone exposure.

EXPERIMENTAL APPROACH

Using Sprague-Dawley rats, the effects of olanzapine and lurasidone on the gut microbiome were explored. Faecal and blood samples were collected weekly over a 21-day period to analyse changes to the gut microbiome and related metabolic markers.

KEY RESULTS

Lurasidone triggered no significant weight gain or metabolic alterations, instead positively modulating the gut microbiome through increases in mean operational taxonomical units (OTUs) and alpha diversity. This novel finding suggests an underlying mechanism for lurasidone's metabolic inertia. In contrast, olanzapine triggered a statistically significant decrease in mean OTUs, substantial compositional variation and a depletion in short-chain fatty acid abundance. Microbiome depletion correlated with metabolic dysfunction, producing a 30% increase in weight gain, increased pro-inflammatory cytokine expression, and increased blood glycaemic and triglyceride levels.

CONCLUSION AND IMPLICATIONS

Our results challenge the notion that all antipsychotics disrupt the gut microbiome similarly and highlights the potential benefits of gut-neutral antipsychotics, such as lurasidone, in managing metabolic side effects. Further research is warranted to validate these findings in humans to guide personalised pharmacological treatment regimens for schizophrenia.

Cellular uptake and in vitro antibacterial activity of lipid-based nanoantibiotics are influenced by protein corona

Bacteria have evolved survival mechanisms that enable them to live within host cells, triggering persistent intracellular infections that present significant clinical challenges due to the inability for conventional antibiotics to permeate cell membranes. In recent years, antibiotic nanocarriers or 'nanoantibiotics' have presented a promising strategy for overcoming intracellular infections by facilitating cellular uptake of antibiotics, thus improving targeting to the bacteria. However, prior to reaching host cells, nanocarriers experience interactions with proteins that form a corona and alter their physiological response. The influence of this protein corona on the cellular uptake, drug release and efficacy of nanoantibiotics for intracellular infections is poorly understood and commonly overlooked in preclinical studies. In this study, protein corona influence on cellular uptake was investigated for two nanoparticles; liposomes and cubosomes in macrophage and epithelial cells that are commonly infected with pathogens. Studies were conducted in presence of fetal bovine serum (FBS) to form a biologically relevant protein corona in an in vitro setting. Protein corona impact on cellular uptake was shown to be nanoparticle-dependent, where reduced internalization was observed for liposomes, the opposite was observed for cubosomes. Subsequently, vancomycin-loaded cubosomes were explored for their drug delivery performance against intracellular small colony variants of Staphylococcus aureus. We demonstrated improved bacterial killing in macrophages, with greater reduction in bacterial viability upon internalization of cubosomes mediated by the protein corona. However, no differences in efficacy were observed in epithelial cells. Thus, this study provides insights and evidence to the role of protein corona in modulating the performance of nanoparticles in a dynamic manner; these findings will facilitate improved understanding and translation of future investigations from in vitro to in vivo.

The Degree of Inulin Polymerization Is Important for Short-Term Amelioration of High-Fat Diet (HFD)-Induced Metabolic Dysfunction and Gut Microbiota Dysbiosis in Rats

Inulin, a non-digestible polysaccharide, has gained attention for its prebiotic properties, particularly in the context of obesity, a condition increasingly understood as a systemic inflammatory state linked to gut microbiota composition. This study investigates the short-term protective effects of inulin with different degrees of polymerization (DPn) against metabolic health deterioration and gut microbiota alterations induced by a high-fat diet (HFD) in Sprague Dawley rats. Inulin treatments with an average DPn of 7, 14, and 27 were administered at 1 g/kg of bodyweight to HFD-fed rats over 21 days. Body weight, systemic glucose levels, and proinflammatory markers were measured to assess metabolic health. Gut microbiota composition was analyzed through 16S rRNA gene sequencing. The results showed that inulin27 significantly reduced total weight gain and systemic glucose levels, suggesting a DPn-specific effect on metabolic health. The study also observed shifts in gut microbial populations, with inulin7 promoting several beneficial taxa from the Bifidobacterium genera, whilst inducing a unique microbial composition compared to medium-chain (DPn 14) and long-chain inulin (DPn: 27). However, the impact of inulin on proinflammatory markers and lipid metabolism parameters was not statistically significant, possibly due to the short study duration. Inulin with a higher DPn has a more pronounced effect on mitigating HFD-induced metabolic health deterioration, whilst inulin7 is particularly effective at inducing healthy microbial shifts. These findings highlight the benefits of inulin as a dietary adjuvant in obesity management and the importance of DPn in optimizing performance.

Effective γδ T-cell clinical therapies: current limitations and future perspectives for cancer immunotherapy

γδ T cells are a unique subset of T lymphocytes, exhibiting features of both innate and adaptive immune cells and are involved with cancer immunosurveillance. They present an attractive alternative to conventional T cell-based immunotherapy due, in large part, to their lack of major histocompatibility (MHC) restriction and ability to secrete high levels of cytokines with well-known anti-tumour functions. To date, clinical trials using γδ T cell-based immunotherapy for a range of haematological and solid cancers have yielded limited success compared with in vitro studies. This inability to translate the efficacy of γδ T-cell therapies from preclinical to clinical trials is attributed to a combination of several factors, e.g. γδ T-cell agonists that are commonly used to stimulate populations of these cells have limited cellular uptake yet rely on intracellular mechanisms; administered γδ T cells display low levels of tumour-infiltration; and there is a gap in the understanding of γδ T-cell inhibitory receptors. This review explores the discrepancy between γδ T-cell clinical and preclinical performance and offers viable avenues to overcome these obstacles. Using more direct γδ T-cell agonists, encapsulating these agonists into lipid nanocarriers to improve their pharmacokinetic and pharmacodynamic profiles and the use of combination therapies to overcome checkpoint inhibition and T-cell exhaustion are ways to bridge the gap between preclinical and clinical success. Given the ability to overcome these limitations, the development of a more targeted γδ T-cell agonist-checkpoint blockade combination therapy has the potential for success in clinical trials which has to date remained elusive.

Minimum Information for Conducting and Reporting In Vitro Intracellular Infection Assays

Bacterial pathogens are constantly evolving to outsmart the host immune system and antibiotics developed to eradicate them. One key strategy involves the ability of bacteria to survive and replicate within host cells, thereby causing intracellular infections. To address this unmet clinical need, researchers are adopting new approaches, such as the development of novel molecules that can penetrate host cells, thus exerting their antimicrobial activity intracellularly, or repurposing existing antibiotics using nanocarriers (i.e., nanoantibiotics) for site-specific delivery. However, inconsistency in information reported across published studies makes it challenging for scientific comparison and judgment of experiments for future direction by researchers. Together with the lack of reproducibility of experiments, these inconsistencies limit the translation of experimental results beyond pre-clinical evaluation. Minimum information guidelines have been instrumental in addressing such challenges in other fields of biomedical research. Guidelines and recommendations provided herein have been designed for researchers as essential parameters to be disclosed when publishing their methodology and results, divided into four main categories: (i) experimental design, (ii) establishing an in vitro model, (iii) assessment of efficacy of novel therapeutics, and (iv) statistical assessment. These guidelines have been designed with the intention to improve the reproducibility and rigor of future studies while enabling quantitative comparisons of published studies, ultimately facilitating translation of emerging antimicrobial technologies into clinically viable therapies that safely and effectively treat intracellular infections.

Combating Acute Myeloid Leukemia via Sphingosine Kinase 1 Inhibitor-Nanomedicine Combination Therapy with Cytarabine or Venetoclax

MP-A08 is a novel sphingosine kinase 1 (SPHK1) inhibitor with activity against acute myeloid leukemia (AML). A rationally designed liposome-based encapsulation and delivery system has been shown to overcome the physicochemical challenges of MP-A08 and enable its effective delivery for improved efficacy and survival of mice engrafted with human AML in preclinical models. To establish therapies that overcome AML's heterogeneous nature, here we explored the combination of MP-A08-loaded liposomes with both the standard chemotherapy, cytarabine, and the targeted therapy, venetoclax, against human AML cell lines. Cytarabine (over the dose range of 0.1-0.5 µM) in combination with MP-A08 liposomes showed significant synergistic effects (as confirmed by the Chou-Talalay Combination Index) against the chemosensitised human AML cell lines MV4-11 and OCI-AML3. Venetoclax (over the dose range of 0.5-250 nM) in combination with MP-A08 liposomes showed significant synergistic effects against the chemosensitised human AML cell lines, particularly in venetoclax-resistant human AML cells. This strong synergistic effect is due to multiple mechanisms of action, i.e., inhibiting MCL-1 through SPHK1 inhibition, leading to ceramide accumulation, activation of protein kinase R, ATF4 upregulation, and NOXA activation, ultimately resulting in MCL-1 degradation. These combination therapies warrant further consideration and investigation in the search for a more comprehensive treatment strategy for AML.

Fibre-rich diet attenuates chemotherapy-related neuroinflammation in mice

The gastrointestinal microbiota has received increasing recognition as a key mediator of neurological conditions with neuroinflammatory features, through its production of the bioactive metabolites, short-chain fatty acids (SCFAs). Although neuroinflammation is a hallmark shared by the neuropsychological complications of chemotherapy (including cognitive impairment, fatigue and depression), the use of microbial-based therapeutics has not previously been studied in this setting. Therefore, we aimed to investigate the effect of a high fibre diet known to modulate the microbiota, and its associated metabolome, on neuroinflammation caused by the common chemotherapeutic agent 5-fluorouracil (5-FU). Twenty-four female C57Bl/6 mice were treated with 5-FU (400 mg/kg, intraperitoneal, i.p.) or vehicle control, with or without a high fibre diet (constituting amylose starch; 4.7 % crude fibre content), given one week prior to 5-FU and until study completion (16 days after 5-FU). Faecal pellets were collected longitudinally for 16S rRNA gene sequencing and terminal SCFA concentrations of the caecal contents were quantified using gas chromatography-mass spectrometry (GC-MS). Neuroinflammation was determined by immunofluorescent analysis of astrocyte density (GFAP). The high fibre diet significantly altered gut microbiota composition, increasing the abundance of Bacteroidaceae and Akkermansiaceae (p < 0.0001 and p = 0.0179) whilst increasing the production of propionate (p = 0.0097). In the context of 5-FU, the diet reduced GFAP expression in the CA1 region of the hippocampus (p < 0.0001) as well as the midbrain (p = 0.0216). Astrocyte density negatively correlated with propionate concentrations and the abundance of Bacteroidaceae and Akkermansiaceae, suggesting a relationship between neuroinflammatory and gastrointestinal markers in this model. This study provides the first evidence of the neuroprotective effects of fibre via dietary intake in alleviating the neuroimmune changes seen in response to systemically administered 5-FU, indicating that the microbiota-gut-brain axis is a targetable mediator to reduce the neurotoxic effects of chemotherapy treatment.

Self-emulsifying drug delivery systems (SEDDS) disrupt the gut microbiota and trigger an intestinal inflammatory response in rats

Self-emulsifying drug delivery systems (i.e. SEDDS, SMEDDS and SNEDDS) are widely employed as solubility and bioavailability enhancing formulation strategies for poorly water-soluble drugs. Despite the capacity for SEDDS to effectively facilitate oral drug absorption, tolerability concerns exist due to the capacity for high concentrations of surfactants (typically present within SEDDS) to induce gastrointestinal toxicity and mucosal irritation. With new knowledge surrounding the role of the gut microbiota in modulating intestinal inflammation and mucosal injury, there is a clear need to determine the impact of SEDDS on the gut microbiota. The current study is the first of its kind to demonstrate the detrimental impact of SEDDS on the gut microbiota of Sprague-Dawley rats, following daily oral administration (100 mg/kg) for 21 days. SEDDS comprising a lipid phase (i.e. Type I, II and III formulations according to the Lipid Formulation Classification Scheme) induced significant changes to the composition and diversity of the gut microbiota, evidenced through a reduction in operational taxonomic units (OTUs) and alpha diversity (Shannon's index), along with statistically significant shifts in beta diversity (according to PERMANOVA of multi-dimensional Bray-Curtis plots). Key signatures of gut microbiota dysbiosis correlated with the increased expression of pro-inflammatory cytokines within the jejunum, while mucosal injury was characterised by significant reductions in plasma citrulline levels, a validated biomarker of enterocyte mass and mucosal barrier integrity. These findings have potential clinical ramifications for chronically administered drugs that are formulated with SEDDS and stresses the need for further studies that investigate dose-dependent effects of SEDDS on the gastrointestinal microenvironment in a clinical setting.

Pre-hospital ECPR in an Australian metropolitan setting: a single-arm feasibility assessment-The CPR, pre-hospital ECPR and early reperfusion (CHEER3) study

INTRODUCTION

Survival from refractory out of hospital cardiac arrest (OHCA) without timely return of spontaneous circulation (ROSC) utilising conventional advanced cardiac life support (ACLS) therapies is dismal. CHEER3 was a safety and feasibility study of pre-hospital deployed extracorporeal membrane oxygenation (ECMO) during cardiopulmonary resuscitation (ECPR) for refractory OHCA in metropolitan Australia.

METHODS

This was a single jurisdiction, single-arm feasibility study. Physicians, with pre-existing ECMO expertise, responded to witnessed OHCA, age < 65 yrs, within 30 min driving-time, using an ECMO equipped rapid response vehicle. If pre-hospital ECPR was undertaken, patients were transported to hospital for investigations and therapies including emergent coronary catheterisation, and standard intensive care (ICU) therapy until either cardiac and neurological recovery or palliation occurred. Analyses were descriptive.

RESULTS

From February 2020 to May 2023, over 117 days, the team responded to 709 "potential cardiac arrest" emergency calls. 358 were confirmed OHCA. Time from emergency call to scene arrival was 27 min (15-37 min). 10 patients fulfilled the pre-defined inclusion criteria and all were successfully cannulated on scene. Time from emergency call to ECMO initiation was 50 min (35-62 min). Time from decision to ECMO support was 16 min (11-26 min). CPR duration was 46 min (32-62 min). All 10 patients were transferred to hospital for investigations and therapy. 4 patients (40%) survived to hospital discharge neurologically intact (CPC 1/2).

CONCLUSION

Pre-hospital ECPR was feasible, using an experienced ECMO team from a single-centre. Overall survival was promising in this highly selected group. Further prospective studies are now warranted.

Battle of the milky way: Lymphatic targeted drug delivery for pathogen eradication

Many viruses, bacteria, and parasites rely on the lymphatic system for survival, replication, and dissemination. While conventional anti-infectives can combat infection-causing agents in the bloodstream, they do not reach the lymphatic system to eradicate the pathogens harboured there. This can result in ineffective drug exposure and reduce treatment effectiveness. By developing effective lymphatic delivery strategies for antiviral, antibacterial, and antiparasitic drugs, their systemic pharmacokinetics may be improved, as would their ability to reach their target pathogens within the lymphatics, thereby improving clinical outcomes in a variety of acute and chronic infections with lymphatic involvement (e.g., acquired immunodeficiency syndrome, tuberculosis, and filariasis). Here, we discuss approaches to targeting anti-infective drugs to the intestinal and dermal lymphatics, aiming to eliminate pathogen reservoirs and interfere with their survival and reproduction inside the lymphatic system. These include optimized lipophilic prodrugs and drug delivery systems that promote lymphatic transport after oral and dermal drug intake. For intestinal lymphatic delivery via the chylomicron pathway, molecules should have logP values >5 and long-chain triglyceride solubilities >50 mg/g, and for dermal lymphatic delivery via interstitial lymphatic drainage, nanoparticle formulations with particle size between 10 and 100 nm are generally preferred. Insight from this review may promote new and improved therapeutic solutions for pathogen eradication and combating infective diseases, as lymphatic system involvement in pathogen dissemination and drug resistance has been neglected compared to other pathways leading to treatment failure.

Targeting Acute Myeloid Leukemia Using Sphingosine Kinase 1 Inhibitor-Loaded Liposomes

Acute myeloid leukemia (AML) kills 75% of patients and represents a major clinical challenge with a need to improve on current treatment approaches. Targeting sphingosine kinase 1 with a novel ATP-competitive-inhibitor, MP-A08, induces cell death in AML. However, limitations in MP-A08's "drug-like properties" (solubility, biodistribution, and potency) hinder its pathway to the clinic. This study demonstrates a liposome-based delivery system of MP-A08 that exhibits enhanced MP-A08 potency against AML cells. MP-A08-liposomes increased MP-A08 efficacy against patient AML cells (>140-fold) and significantly prolonged overall survival of mice with human AML disease (P = 0.03). The significant antileukemic property of MP-A08-liposomes could be attributed to its enhanced specificity, bioaccessibility, and delivery to the bone marrow, as demonstrated in the pharmacokinetic and biodistribution studies. Our findings indicate that MP-A08-liposomes have potential as a novel treatment for AML.

Liposome-Micelle-Hybrid (LMH) Carriers for Controlled Co-Delivery of 5-FU and Paclitaxel as Chemotherapeutics

Paclitaxel (PTX) and 5-fluorouracil (5-FU) are clinically relevant chemotherapeutics, but both suffer a range of biopharmaceutical challenges (e.g., either low solubility or permeability and limited controlled release from nanocarriers), which reduces their effectiveness in new medicines. Anticancer drugs have several major limitations, which include non-specificity, wide biological distribution, a short half-life, and systemic toxicity. Here, we investigate the potential of liposome-micelle-hybrid (LMH) carriers (i.e., drug-loaded micelles encapsulated within drug-loaded liposomes) to enhance the co-formulation and delivery of PTX and 5-FU, facilitating new delivery opportunities with enhanced chemotherapeutic performance. We focus on the combination of liposomes and micelles for co-delivery of PTX and 5_FU to investigate increased drug loading, improved solubility, and transport/permeability to enhance chemotherapeutic potential. Furthermore, combination chemotherapy (i.e., containing two or more drugs in a single formulation) may offer improved pharmacological performance. Compared with individual liposome and micelle formulations, the optimized PTX-5FU-LMH carriers demonstrated increased drug loading and solubility, temperature-sensitive release, enhanced permeability in a Caco-2 cell monolayer model, and cancer cell eradication. LMH has significant potential for cancer drug delivery and as a next-generation chemotherapeutic.

Targeting the gut microbiome to control drug pharmacomicrobiomics: the next frontier in oral drug delivery

INTRODUCTION

The trillions of microorganisms that comprise the gut microbiome form dynamic bidirectional interactions with orally administered drugs and host health. These relationships can alter all aspects of drug pharmacokinetics and pharmacodynamics (PK/PD); thus, there is a desire to control these interactions to maximize therapeutic efficacy. Attempts to modulate drug-gut microbiome interactions have spurred advancements within the field of 'pharmacomicrobiomics' and are poised to become the next frontier of oral drug delivery.

AREAS COVERED

This review details the bidirectional interactions that exist between oral drugs and the gut microbiome, with clinically relevant case examples outlining a clear motive for controlling pharmacomicrobiomic interactions. Specific focus is attributed to novel and advanced strategies that have demonstrated success in mediating drug-gut microbiome interactions.

EXPERT OPINION

Co-administration of gut-active supplements (e.g. pro- and pre-biotics), innovative drug delivery vehicles, and strategic polypharmacy serve as the most promising and clinically viable approaches for controlling pharmacomicrobiomic interactions. Targeting the gut microbiome through these strategies presents new opportunities for improving therapeutic efficacy by precisely mediating PK/PD, while mitigating metabolic disturbances caused by drug-induced gut dysbiosis. However, successfully translating preclinical potential into clinical outcomes relies on overcoming key challenges related to interindividual variability in microbiome composition and study design parameters.

The impact of common pharmaceutical excipients on the gut microbiota

INTRODUCTION

Increasing attention is being afforded to understanding the bidirectional relationships that exist between oral medications and the gut microbiota, in an attempt to optimize pharmacokinetic performance and mitigate unwanted side effects. While a wealth of research has investigated the direct impact of active pharmaceutical ingredients (APIs) on the gut microbiota, the interactions between inactive pharmaceutical ingredients (i.e. excipients) and the gut microbiota are commonly overlooked, despite excipients typically representing over 90% of the final dosage form.

AREAS COVERED

Known excipient-gut microbiota interactions for various classes of inactive pharmaceutical ingredients, including solubilizing agents, binders, fillers, sweeteners, and color additives, are reviewed in detail.

EXPERT OPINION

Clear evidence indicates that orally administered pharmaceutical excipients directly interact with gut microbes and can either positively or negatively impact gut microbiota diversity and composition. However, these relationships and mechanisms are commonly overlooked during drug formulation, despite the potential for excipient-microbiota interactions to alter drug pharmacokinetics and interfere with host metabolic health. The insights derived from this review will inform pharmaceutical scientists with the necessary design considerations for mitigating potential adverse pharmacomicrobiomic interactions when formulating oral dosage forms, ultimately providing clear avenues for improving therapeutic safety and efficacy.

Inulin-lipid hybrid (ILH) microparticles promote pH-triggered release of rifampicin within infected macrophages

Intracellular bacteria serve as a problematic source of infection due to their ability to evade biological immune responses and the inability for conventional antibiotics to efficiently penetrate cellular membranes. Subsequently, new treatment approaches are urgently required to effectively eradicate intracellular pathogens residing within immune cells (e.g. macrophages). In this study, the poorly soluble and poorly permeable antibiotic, rifampicin, was re-purposed via micro-encapsulation within inulin-lipid hybrid (ILH) particles for the treatment of macrophages infected with small colony variants of Staphylococcus aureus (SCV S. aureus). Rifampicin-encapsulated ILH (Rif-ILH) microparticles were synthesized by spray drying a lipid nano-emulsion, with inulin dissolved throughout the aqueous phase and rifampicin pre-loaded within the lipid phase. Rif-ILH were strategically designed and engineered with pH-responsive properties to promote lysosomal drug release upon cellular internalization, while preventing premature rifampicin release in plasma-simulating media. The pH-responsiveness of Rif-ILH was controlled by the acid-mediated hydrolysis of the inulin coating, where exposure to acidic media simulating the lysosomal environment of macrophages triggered hydrolysis of the oligofructose chain and the subsequent diffusion of rifampicin from Rif-ILH. This pH-provoked release mechanism, as well as the ability for ILH microparticles to be more readily internalized by macrophages, was found to be influential in triggering a 2.9-fold increase in intracellular rifampicin concentration within infected macrophages, compared to the pure drug. The subsequent increase in exposure of intracellular pathogens to rifampicin leads to a ~ 2-log improvement in antibacterial activity for Rif-ILH, at a rifampicin dose of 2.5 µg/mL. Thus, the reduction in viability of intracellular SCV S. aureus, in the absence of cellular toxicity, is indicative of ILH microparticles serving as a unique approach for the safe and efficacious delivery of antibiotics to phagocytic cells for the treatment of intracellular infections.

Liquid crystalline lipid nanoparticles improve the antibacterial activity of tobramycin and vancomycin against intracellular Pseudomonas aeruginosa and Staphylococcus aureus

The intracellular survival of bacteria is a significant challenge in the fight against antimicrobial resistance. Currently available antibiotics suffer from limited penetration across host cell membranes, resulting in suboptimal treatment against the internalised bacteria. Liquid crystalline nanoparticles (LCNP) are gaining significant research interest in promoting the cellular uptake of therapeutics due to their fusogenic properties; however, they have not been reported for targeting intracellular bacteria. Herein, the cellular internalisation of LCNPs in RAW 264.7 macrophages and A549 epithelial cells was investigated and optimized through the incorporation of a cationic lipid, dimethyldioctadecylammonium bromide (DDAB). LCNPs displayed a honeycomb-like structure, while the inclusion of DDAB resulted into an onion-like organisation with larger internal pores. Cationic LCNPs enhanced the cellular uptake in both cells, reaching up to ∼90% uptake in cells. Further, LCNPs were encapsulated with tobramycin or vancomycin to improve their activity against intracellular gram-negative, Pseudomonas aeruginosa (P. aeruginosa) and gram-positive, Staphylococcus aureus (S. aureus) bacteria. The enhanced cellular uptake of cationic LCNP resulted in significant reduction of intracellular bacterial load (up to 90% reduction), compared to antibiotic dosed in its free form; with reduced performance observed for epithelial cells infected with S. aureus. Specifically engineered LCNP can re-sensitise antibiotics against both intracellular Gram positive and negative bacteria in diverse cell lines.

A membrane-free microfluidic approach to mucus permeation for efficient differentiation of mucoadhesive and mucopermeating nanoparticulate systems

The gastrointestinal mucus barrier is a widely overlooked yet essential component of the intestinal epithelium, responsible for the body's protection against harmful pathogens and particulates. This, coupled with the increasing utilisation of biological molecules as therapeutics (e.g. monoclonal antibodies, RNA vaccines and synthetic proteins) and nanoparticle formulations for drug delivery, necessitates that we consider the additional absorption barrier that the mucus layer may pose. It is imperative that in vitro permeability methods can accurately model this barrier in addition to standardised cellular testing. In this study, a mucus-on-a-chip (MOAC) microfluidic device was engineered and developed to quantify the permeation kinetics of nanoparticles through a biorelevant synthetic mucus layer. Three equivalently sized nanoparticle systems, formulated from chitosan (CSNP), mesoporous silica (MSNP) and poly (lactic-co-glycolic) acid (PLGA-NP) were prepared to encompass various surface chemistries and nanostructures and were assessed for their mucopermeation within the MOAC. Utilising this device, the mucoadhesive behaviour of chitosan nanoparticles was clearly visualised, a phenomenon not often observed via standard permeation models. In contrast, MSNP and PLGA-NP displayed mucopermeation, with significant differences in permeation pattern due to specific mucus-nanoparticle binding. Further optimisation of the MOAC to include a more biorelevant mucus mimic resulted in 5.5-fold hindered PLGA-NP permeation compared to a mucin solution. Furthermore, tracking of PLGA-NP at a single nanoparticle resolution revealed rank-order correlations between particle diffusivity and MOAC permeation. This device, including utilisation of biosimilar mucus, provides a unique ability to quantify both mucoadhesion and mucopenetration of nano-formulations and elucidate mucus binding interactions on a microscopic scale.

Protein adsorption determines pulmonary cell uptake of lipid-based nanoparticles

The inhalable administration of lipid nanoparticles is an effective strategy for localised delivery of therapeutics against various lung diseases. Of this, improved intracellular delivery of pharmaceuticals for infectious disease and cancer management is of high significance. However, the influence of lipid nanoparticle composition and structure on uptake in pulmonary cell lines, especially in the presence of biologically relevant media is poorly understood. Here, the uptake of lamellar (liposomes) versus non-lamellar (cubosomes) lipid nanoparticles in macrophages and lung epithelial cells was quantified and the influence of bronchoalveolar lavage fluid (BALF), containing native pulmonary protein and surfactant molecules is determined. Cubosome uptake in both macrophages and epithelial cells was strongly mediated by a high percentage of molecular function regulatory and binding proteins present within the protein corona. In contrast, the protein corona did not influence the uptake of liposomes in epithelial cells. In macrophages, the proteins mediated a rapid internalisation, followed by exocytosis of liposomes after 6 h incubation. These findings on the influence of biological fluid in regulating lipid nanoparticle uptake mechanisms may guide future development of optimal intracellular delivery systems for therapeutics via the pulmonary route.

Net overboard: Comparing marine eDNA sampling methodologies at sea to unravel marine biodiversity

Environmental DNA (eDNA) analyses are powerful for describing marine biodiversity but must be optimized for their effective use in routine monitoring. To maximize eDNA detection probabilities of sparsely distributed populations, water samples are usually concentrated from larger volumes and filtered using fine-pore membranes, often a significant cost-time bottleneck in the workflow. This study aimed to streamline eDNA sampling by investigating plankton net versus bucket sampling, direct versus sequential filtration including self-preserving filters. Biodiversity was assessed using metabarcoding of the small ribosomal subunit (18S rRNA) and mitochondrial cytochrome c oxidase I (COI) genes. Multispecies detection probabilities were estimated for each workflow using a probabilistic occupancy modelling approach. Significant workflow-related differences in biodiversity metrics were reported. Highest amplicon sequence variant (ASV) richness was attained by the bucket sampling combined with self-preserving filters, comprising a large portion of microplankton. Less diversity but more metazoan taxa were captured in the net samples combined with 5 μm pore size filters. Prefiltered 1.2 μm samples yielded few or no unique ASVs. The highest average (~32%) metazoan detection probabilities in the 5 μm pore size net samples confirmed the effectiveness of preconcentration plankton for biodiversity screening. These results contribute to streamlining eDNA sampling protocols for uptake and implementation in marine biodiversity research and surveillance.