Bile Acids and Their Derivatives as Potential Modifiers of Drug Release and Pharmacokinetic Profiles

Nanoparticle-Based gene therapy strategies in retinal delivery

Vision loss and blindness are significant issues in both developed and developing countries. There are a wide variety of aetiologies that can cause vision loss, which are outlined in this review. Although treatment has significantly improved over time for some conditions, nearly half of all people with vision impairment are left untreated. Gene delivery is an emerging field that may assist with the treatment of some of these difficult to manage forms of vision loss. Here we review how a component of nanotechnology-based, non-viral gene delivery systems are being applied to help resolve vision impairment. This review focuses on the use of lipid and polymer nanoparticles, and quantum dots as gene delivery vectors to the eye. Finally, we also highlight some emerging technologies that may be useful in this discipline.

Bile acid therapy for primary biliary cholangitis: Pathogenetic validation

Knowledge of the etiological and pathogenetic mechanisms of the development of any disease is essential for its treatment. Because the cause of primary biliary cholangitis (PBC), a chronic, slowly progressive cholestatic liver disease, is still unknown, treatment remains symptomatic. Knowledge of the physicochemical properties of various bile acids and the adaptive responses of cholangiocytes and hepatocytes to them has provided an important basis for the development of relatively effective drugs based on hydrophilic bile acids that can potentially slow the progression of the disease. Advances in the use of hydrophilic bile acids for the treatment of PBC are also associated with the discovery of pathogenetic mechanisms of the development of cholangiocyte damage and the appearance of the first signs of this disease. For 35 years, ursodeoxycholic acid (UDCA) has been the unique drug of choice for the treatment of patients with PBC. In recent years, the list of hydrophilic bile acids used to treat cholestatic liver diseases, including PBC, has expanded. In addition to UDCA, the use of obeticholic acid, tauroursodeoxycholic acid and norursodeoxycholic acid as drugs is discussed. The pathogenetic rationale for treatment of PBC with various bile acid drugs is discussed in this review. Emphasis is made on the mechanisms explaining the beneficial therapeutic effects and potential of each of the bile acid as a drug, based on the understanding of the pathogenesis of the initial stages of PBC.

The Pharmaceutical and Pharmacological Potential Applications of Bilosomes as Nanocarriers for Drug Delivery

Nano-drug delivery systems provide targeted solutions for addressing various drug delivery challenges, leveraging nanotechnology to enhance drug solubility and permeability. Liposomes, explored for several decades, face hurdles, especially in oral delivery. Bile-acid stabilized vesicles (bilosomes) are flexible lipid vesicles, composed of phospholipids or other surfactants, along with amphiphilic bile salts, and they show superior stability and pharmacokinetic behavior in comparison to conventional vesicular systems (liposomes and niosomes). Bilosomes enhance skin penetration, fluidize the stratum corneum, and improve drug stability. In oral applications, bilosomes overcome drawbacks, offering improved bioavailability, controlled release, and reduced side effects. Vaccines using bilosomes demonstrate efficacy, and bilosomes for intranasal, inhalation, ocular, and buccal applications enhance drug delivery, offering targeted, efficient, and controlled activities. Formulations vary based on active substances and optimization techniques, showcasing the versatility and potential of bilosomes across diverse drug delivery routes. Therefore, the aim of this comprehensive review was to critically explore the state-of-the-art of bilosomes in drug delivery and potential therapeutic applications.

Innovative approaches to cationic and anionic (catanionic) amphiphiles self-assemblies: Synthesis, properties, and industrial applications

Meeting the contemporary demand for the development of functional, biocompatible, and environment friendly self-assembled structures using efficient, cost-effective, and energy-saving methods, the field of colloids has witnessed a surge in interest. Research into cationic and anionic (catanionic) surfactant combinations has gained momentum due to their distinct advantages and synergistic properties in this context. Catanionic self-assemblies have emerged as promising contenders for addressing these requirements. Catanionic self-assemblies possess high stability, adjustable surface charge, and low critical aggregation concentration. This comprehensive review article distinguishes between cationic/anionic non-equimolar and equimolar ratio mixing formation of high-salt catanionic self-assemblies known as catanionic mixture and salt-free counterparts, termed ion-pair amphiphiles, respectively. It explores diverse synthesis techniques, emphasizing the roles of solvents, salts, and pH conditions and covers both experimental and theoretical aspects of state-of-the-art catanionic self-assemblies. Additionally, the review investigates the development of multi-responsive catanionic self-assemblies using light, pH, temperature, and redox, responsive cationic/anionic amphiphiles. It provides an in-depth exploration of potential synergistic interactions and properties, underscoring their practical importance in a wide range of industrial applications. The review explores challenges like precipitation, stability and identifies knowledge gaps, creating opportunities in the dynamic catanionic self-assembly field. It aims to offer insights into the journey of catanionic self-assemblies, from inception to current status, appealing to a broad audience invested in their scientific and industrial potential.

TUDCA modulates drug bioavailability to regulate resistance to acute ER stress in Saccharomyces cerevisiae

Cells counter accumulation of misfolded secretory proteins in the endoplasmic reticulum (ER) through activation of the Unfolded Protein Response (UPR). Small molecules termed chemical chaperones can promote protein folding to alleviate ER stress. The bile acid tauroursodeoxycholic acid (TUDCA) has been described as a chemical chaperone. While promising in models of protein folding diseases, TUDCA's mechanism of action remains unclear. Here, we found TUDCA can rescue growth of yeast treated with the ER stressor tunicamycin (Tm), even in the absence of a functional UPR. In contrast, TUDCA failed to rescue growth on other ER stressors. Nor could TUDCA attenuate chronic UPR associated with specific gene deletions or overexpression of a misfolded mutant secretory protein. Neither pretreatment with nor delayed addition of TUDCA conferred protection against Tm. Importantly, attenuation of Tm-induced toxicity required TUDCA's critical micelle forming concentration, suggesting a mechanism where TUDCA directly sequesters drugs. Indeed, in several assays, TUDCA-treated cells closely resembled cells treated with lower doses of Tm. In addition, we found TUDCA can inhibit dyes from labeling intracellular compartments. Thus, our study challenges the model of TUDCA as a chemical chaperone and suggests that TUDCA decreases drug bioavailability, allowing cells to adapt to ER stress.

Gastrointestinal Bile Salt Concentrations in Healthy Adults Under Fasted and Fed Conditions: A Systematic Review and Meta-Analysis for Mechanistic Physiologically-Based Pharmacokinetic (PBPK) Modelling

Bile salts are biosurfactants released into the intestinal lumen which play an important role in the solubilisation of fats and certain drugs. Their concentrations vary along the gastrointestinal tract (GIT). This is significant for implementation in physiologically based pharmacokinetic (PBPK) modelling to mechanistically capture drug absorption. The aims of this meta-analysis were to collate all appropriate data on intestinal bile salt concentrations in healthy adults across all GIT segments in fasted and fed states for the purpose of PBPK modelling. Terms relating to bile composition were searched in PubMed and Google Scholar from inception to May 2024. Selected studies included aspirated intestinal fluid collected via gastric tubes or colonoscopy. Results showed high variability across studies and a time-dependency for the fed state. Data were rich for the duodenum, which showed a two-fold increase for the fed state versus the fasted state within multiple studies. Peaks and troughs in bile salt concentrations along the GIT were observed for both fasted and fed states, likely due to segmental water absorption differences. The highest between subject variability was observed for the duodenum in the fasted and fed state and the fed proximal jejunum, distal ileum, and colon. The findings from this meta-analysis can be used for the purpose of PBPK modelling to capture segmental drug solubilisation and absorption in fasted and fed states. However, data are lacking under different fed conditions, especially following low-fat meals, so the impact of different fat content associated with different meals on bile salt concentrations cannot be discerned.

Anthracene-Conjugated Steroidal Amphiphiles: Soft Functional Materials Exhibiting Supramolecular Aggregation Induced Enhanced Emission with Potential Applications as Drug Carriers and Fluorescent Bioprobes

Bile salts (BS) are naturally occurring steroidal biosurfactants. The ease of functionalization of BSs has boosted their use as inexpensive building blocks for the fabrication of a broad set of value-added soft functional materials. In the present work, three fluorescent bile acid (FBA) derivatives have been synthesized by conjugating anthracene at the side chain of lithocholic acid, deoxycholic acid, and cholic acid to understand the effect of the nature of the steroid nucleus on their physicochemical properties. In an aqueous medium, the FBAs showed a strong supramolecular aggregation propensity, even in the micromolar concentration range, which is in contrast to their BS analogues that form micelles mostly in the millimolar range. The FBA aggregation leads to a prearranged geometry in the ground state with a favorable orientation of anthracene units for excimer formation on excitation, leading to supramolecular aggregation-induced enhanced emission (AIEE). A detailed investigation reveals the pivotal role of the steroidal skeleton in their aggregation propensity and optical behavior. The FBA assemblies, with ordered structures plus anthracene being a part of their building blocks, are endowed with interesting properties different from those in dilute organic media, which makes them extremely attractive for diverse applications, e.g., as potential drug carriers owing to their ability to serve as efficient hosts for the protective encapsulation of hydrophobic guests; as membrane probes and bioimaging agents due to their efficient membrane permeability and cell-imaging ability; and as system probes because of their remarkable sensitivity toward the aggregation process of natural bile salts in the aqueous medium. Therefore, the present study not only enhances the fundamental understanding of this unique class of amphiphiles but also opens new prospects in tailoring novel self-assembled soft functional materials. Moreover, it offers a benchmark for developing BS-based fluorescent derivatives with unique photophysical characteristics for applications as potential bioprobes.

Effect of Cholic Acid Salt and Its Mixed Micelles on the Morphology of Giant Unilamellar Vesicles (GUV)

Bile salts, present in the gastrointestinal tract as biosurfactants, play a crucial role in emulsifying and solubilizing fat-soluble nutrients and drugs, thereby facilitating their absorption. However, the cellular permeation of bile acid-mixed micelles solubilized with lipophilic substances remains inadequately explored. To comprehend the cell permeation behavior of bile salts and their mixed micelles, giant unilamellar vesicles (GUVs) were employed as a cell-mimetic system, prepared with dioleylphosphatidylcholine (DOPC). Confocal laser scanning microscopy, utilizing fluorescent dyes doped in the lipid membrane and solubilized substances, was employed to observe morphological changes in GUVs subsequent to the application of sodium cholate (NaC) alone and NaC-mixed micelles solubilized with lipophilic components. In the case of NaC alone, below the critical micelle concentration (CMC), the monomer interacts with the lipid membrane of the GUV, inducing endocytic morphological changes that result in the formation of small vesicles containing the bulk liquid inside the GUV. Conversely, when both monomers and micelles interacted with the lipid membrane beyond the CMC, lipid aggregates such as buds and threads protruded outward from the GUV. Contrastingly, upon application of three types of NaC mixed micelles-NaC-P solubilized with Palmitoyloleoylphosphocholine (POPC), NaC-P-F solubilized with oleic acid (OA) and monoolein (MO), and NaC-P-P solubilized with perylene, a liposoluble dye-to the GUV, the lipid membranes formed aggregates or vesicles and migrated into the interior of the GUV. In the case of NaC-P and NaC-P-P, the coexistence of drawn lipid aggregates and solubilized substances was scarcely observed. In contrast, for NaC-P-F, the coexistence of solubilized substances was observed in both lipid aggregates and small vesicles that migrated into the GUV. It is suggested that the partitioning of the solubilized substance from the mixed micelles adsorbed on the GUV to the lipid bilayer is implicated in the permeation of the solubilized substance through the cell membrane.

Tasurgratinib in patients with cholangiocarcinoma or gastric cancer: Expansion part of the first-in-human phase I study

Fibroblast growth factor receptors (FGFRs) are a highly conserved family of transmembrane receptor tyrosine kinases with multiple roles in the regulation of key cellular processes. Specific FGFR mutations have been observed in several types of cancers, including gastric carcinoma and cholangiocarcinoma. Dose escalation data of 24 Japanese patients with solid tumors treated with Tasurgratinib (previously known as E7090), a potent, selective FGFR1-3 inhibitor, was reported in a phase I, first-in-human, single-center study. Based on the safety, pharmacokinetic, and pharmacodynamic profiles observed in this study, the recommended dose of 140 mg once daily was selected for the expansion part (Part 2), a multicenter expansion of the dose-finding study restricted to patients with tumors harboring FGFR gene alterations. Safety and preliminary efficacy were assessed in Part 2. Pharmacodynamic pharmacogenomic markers (serum phosphate, FGF23, and 1,25-(OH)2-vitamin D, circulating tumor DNA) and pharmacokinetic profiles were also evaluated. A total of 16 patients were enrolled in Part 2, six with cholangiocarcinoma and 10 with gastric cancer. The most common treatment-emergent adverse events were hyperphosphatemia, palmar-plantar erythrodysesthesia syndrome, and paronychia. Five partial responses (83.3%) in cholangiocarcinoma patients and one partial response (11.1%) in gastric cancer patients were observed; median progression-free survival was 8.26 months (95% confidence interval [CI] 3.84, not evaluable [NE]) and 3.25 months (95% CI 0.95, 4.86), and overall survival was 22.49 months (95% CI 6.37, NE) and 4.27 months (95% CI 2.23, 7.95), respectively, in the two groups. In conclusion, Tasurgratinib 140 mg has a tolerable safety profile with good clinical efficacy in patients with cholangiocarcinoma harboring FGFR2 gene rearrangements.

Taurodeoxycholate Aggregation Explored by Molecular Dynamics: Primary-To-Secondary Micelle Transition and Formation of Mixed Micelles with Fatty Acids

Micelles formed by bile salts in aqueous solution are important for the solubilization of hydrophobic molecules in the gastrointestinal tract. The molecular level information about the mechanism and driving forces for primary-to-secondary micelle transition is still missing. In the current study, the micelle formation of 50 mM solutions of taurodeoxycholate (TDC) is studied by atomistic molecular dynamics simulations. It is shown that primary micelles with an aggregation number of 8-10 emerge and persist within the first 50 ns. Then, they coalesce to form secondary micelles with an aggregation number of 19 molecules. This transition is governed by hydrophobic interactions, which significantly decrease the solvent-accessible surface area per molecule in the secondary micelles. The addition of monomers of the sodium salt of fatty acids (FAs), as agents aiding hydrophobic drug delivery, to secondary TDC micelles results in the co-existence of mixed FA-TDC and pure FA micelles. The studied saturated FAs, with chain lengths of C14:0 and C18:0, are incorporated into the micelle core, whereas TDC molecules position themselves around the FAs, forming a shell on the micelle surface. In contrast, the tails of the C18:1 unsaturated fatty acid mix homogeneously with TDC molecules throughout the entire micelle volume. The latter creates a very suitable medium for hosting hydrophobic molecules in the micelles containing unsaturated fatty acids.

Novel Lipid Formulation Increases Absorption of Oral Cannabidiol (CBD)

Background: Cannabidiol (CBD) is an approved treatment for childhood epilepsies and a candidate treatment for several other CNS disorders. However, it has poor oral bioavailability. We investigated the effect of a novel lipid formulation on its absorption in humans and on its tissue distribution in mice. Methods: In a double-blind crossover study in fasting healthy volunteers, we compared the pharmacokinetics of a single dose of 1000 mg of CBD in the lipid formulation and in a powder formulation (ClinicalTrials.gov: NCT05032807). In a second study, male CD1 mice were administered CBD in either the lipid formulation or dissolved in water, via oral gavage (n = 1 per timepoint). The tissue distribution of CBD was assessed using matrix-assisted laser desorption/ionization mass spectrometric imaging. Results: Plasma exposure (AUC0-48) of CBD was nine times greater for the lipid formulation than the powder formulation (611.1 ng·h/mL [coefficient of variation {CV%}: 104.6] and 66.8 ng·h/mL [CV%: 50.7], respectively). With the powder formulation, the AUC0-48 was related to the concentration of specific gastrointestinal bacteria and bile acids. These associations were attenuated with the lipid formulation. In the animal study, after treatment with the lipid formulation, measurable concentrations of CBD were identified in all organs. For the aqueous formulation, tissue concentrations of CBD were below the limit of quantification. Conclusions: Administering oral CBD in a lipid formulation was associated with an increase in its gastrointestinal absorption, as well as an attenuation of the relationship between its absorption and features of the gut microbiome.

Neuroprotective efficiency of celecoxib vesicular bilosomes for the management of lipopolysaccharide-induced Alzheimer in mice employing 23 full factorial design

The aim of this study was to develop and evaluate bilosomes loaded with Celecoxib (CXB) for the efficient treatment of Alzheimer. The thin-film hydration approach was utilized in the formulation of CXB bilosomes (CXB-BLs). The study used a 23-factorial design to investigate the impact of several formulation variables. Three separate parameters were investigated: bile salt type (X1), medication amount (X2), and lipid-bile salt ratio (X3). The dependent responses included entrapment efficiency (Y1: EE %), particle size (Y2: PS), and zeta potential (Y3: ZP). The formulation factors were statistically optimized using the Design-Expert® program. The vesicles demonstrated remarkable CXB encapsulation efficiency, ranging from 94.16 ± 1.91 to 98.38 ± 0.85%. The vesicle sizes ranged from 241.8 ± 6.74 to 352 ± 2.34 nm. The produced formulations have high negative zeta potential values, indicating strong stability. Transmission electron microscopy (TEM) revealed that the optimized vesicles had a spherical form. CXB release from BLs was biphasic, with the release pattern following Higuchi's model. In vivo studies confirmed the efficiency of CXB-BLs in management of lipopolysaccharide-induced Alzheimer as CXB-BLs ameliorated cognitive dysfunction, decreased acetylcholinesterase (AChE), and inhibited neuro-inflammation and neuro-degeneration through reducing Toll-like receptor (TLR4), and Interleukin-1β (IL-1β) levels. The findings suggested that the created CXB-BLs could be a potential drug delivery strategy for Alzheimer's treatment.

Dermal drug delivery via bilosomes: a synergistic integration for better therapeutic outcomes

The dermal route is commonly used to deliver the drugs at the targeted site and achieve maximum therapeutic efficacy. The stratum corneum, the uppermost layer of the skin, presents a significant diffusional barrier for most drugs. Various nanoformulations face challenges such as limited drug absorption and inadequate retention at the targeted site, frequently hindering therapeutic efficacy. Researchers are increasingly exploring innovative strategies that leverage nanotechnology and specialized carriers to address these challenges and enhance the outcomes of dermal medications. A novel drug delivery system, bilosomes, has been designed as a potential vesicular carrier system for the dermal route. Bilosomes are colloidal, lipid-based vesicles stabilized with bile salts, offering greater stability during storage and transportation. The lipid bilayer of bilosomes imparts ultra-flexibility, facilitating penetration through the stratum corneum. This review explores the use of bilosomes in dermal formulations for treating diverse diseases, their developmental techniques, and characterization, and it sheds light on their advantages over traditional lipid nanocarriers.

Advanced drug delivery strategies for diabetic retinopathy: current therapeutic advancement, and delivery methods overcoming barriers, and experimental modalities

INTRODUCTION

Diabetic retinopathy, a significant trigger for blindness among working age individuals with diabetes, poses a substantial global health challenge. Understanding its underlying mechanisms is pivotal for developing effective treatments. Current treatment options, such as anti-VEGF agents, corticosteroids, laser photocoagulation, and vitreous surgery, have their limitations, prompting the exploration of innovative approaches like nanocapsules based drug-delivery systems. Nanoparticles provide promising solutions to improve drug delivery in ocular medicine, overcoming the complexities of ocular anatomy and existing treatment constraints.

AREAS COVERED

This review explored advanced therapeutic strategies for diabetic retinopathy, focusing on current medications with their limitations, drug delivery methods, device innovations, and overcoming associated barriers. Through comprehensive review, it aimed to contribute to the discovery of more efficient management strategies for diabetic retinopathy in the future.

EXPERT OPINION

In the next five to ten years, we expect a revolutionary shift in how diabetic retinopathy is treated. As we deepen our understanding of oxidative stress and metabolic dysfunction, antioxidants with specialised delivery matrices are poised to take center stage in prevention and treatment strategies. Our vision is to create a more integrated approach to diabetic retinopathy management that not only improves patient outcomes but also reduces the risks associated to traditional therapies.

Understanding the Impact of Lipids on the Solubilizing Capacity of Human Intestinal Fluids

Lipids in human intestinal fluids (HIF) form various structures, resulting in phase separation in the form of a lipid fraction and a micellar aqueous fraction. Currently used fed state simulated intestinal fluids (SIF) lack phase separation, highlighting the need for a deeper understanding of the effect of these fractions on intestinal drug solubilization in HIF to improve simulation accuracy. In this study, duodenal fluids aspirated from 21 healthy volunteers in fasted, early fed, and late fed states were used to generate 7 HIF pools for each prandial state. The apparent solubility of seven lipophilic model drugs was measured across these HIF pools, differentiating between the micellar fraction and the total sample (including both micellar and lipid fractions). The solubilizing capacities of these fluids were analyzed in relation to their composition, including total lipids, bile salts, phospholipids, total cholesterol, pH, and total protein. The solubility data generated in this work demonstrated that current fed state SIF effectively predicted the average solubility in the micellar fraction of HIF but failed to discern the considerable variability between HIF pools. Furthermore, the inclusion of a lipid fraction significantly enhanced the solubility of fed state HIF pools, resulting on average in a 13.9-fold increase in solubilizing capacity across the seven model compounds. Although the average composition of the fluids was consistent with previous studies, substantial variability was observed in micellar lipid concentrations, despite relatively stable total lipid concentrations. This variability is critical, as evidenced by the strong correlations between the solubilizing capacity of the micellar fraction and its micellar lipid concentrations. Additionally, this study identified that fluctuations in bile salt concentrations and pH contributed to the observed variability in micellar lipid concentration. In summary, the influence of the lipid fraction on solubility was 2-fold: it enhanced the solubility of lipophilic drugs in the total fluid, and contributed to the variability in the solubilizing capacity of the micellar fraction.

Synthesis of N-acetylcysteine functionalized cholic acid based triarmed poly DL-Lactide and encapsulation of gold nanoparticles: Studies on the antimicrobial activity and biocompatibility for drug delivery applications

Cholic acid based biodegradable reverse polymeric micelles have been widely utilized as preclinically suitable drug delivery system for poorly water-soluble drugs. In this report, we developed N-acetylcysteine functionalized cholic acid based triarmed poly (Dl-lactide) (ACyCA-triarmed (DLL)n as reversed polymeric micelles for drug delivery studies. ACyCA was synthesized via thiol-yne click reaction and subsequently used as an initiator for the synthesis of ACyCA-triarmed (DLL)n through ring opening polymerization (ROP) using Sn (Oct)2 as a catalyst. The synthesized ACyCA-triarmed (DLL)n was characterized using GPC, FT-IR, 1H NMR, 13C NMR, spectrofluorometer, HR-TEM, DSC, TGA, XRD, DLS, and zeta potential techniques. The reverse critical micellar concentration of the polymer was determined to be 1.99 mg/mL using a spectrofluorometer. The synthesized reverse micelles (RMs) were utilized as a reducing and capping agent for the preparation of AuNPs under sunlight exposure. The formed AuNPs exhibited spherical in shape with an average size of ∼ 23.4 nm and Dh was found to be 86.8 ± 1.3 nm as evidenced by the TEM and DLS analysis. Furthermore, the antimicrobial activity, hemolytic activity, anti-oxidant activity, and in-vitro drug release studies were examined for the RMs-AuNPs and compared with RMs. The hydrophobic nature of RMs and RMs-AuNPs had better haemocompatibility at above the reversed CMC. The antioxidant activity RMs-AuNPs showed better inhibitory effect in a dose-dependent manner as compared to RMs. The RMs-AuNPs formulation act as reservoir for solubilization of hydrophobic doxorubicin (Dox.HCl) drugs and can be used as therapeutic platform for slow and sustained release of drugs in biological medium.

Bile acid conjugated chitosan nanoparticles promote the proliferation and epithelial-mesenchymal transition of hepatocellular carcinoma by regulating the PI3K/Akt/mTOR pathway

Bile acids have been known to play significant roles at certain physiological levels in gastrointestinal metabolism. Yet, they are known to be carcinogenic and aid in tumor progression in most cases, although the roles remain uncertain. Hence, we tested the cytotoxic potential of cholic acid (CA) loaded chitosan nanoparticles (CNPs) on Hep3B cells. The physicochemical properties of the CNPs synthesized with CA load (CA-CNPs) were determined using standard techniques such as ultraviolet-visible spectrophotometry (UV-Vis), fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), dynamic light scattering (DLS) and transmission electron microscopy (TEM). The characteristic peak for chitosan nanoparticles were observed for plain CNPs (pCNPs) and CA-CNPs at around 300 nm as per UV-Vis analysis. FTIR analysis indicated the possible trapping of CA onto CNPs as certain peaks were retained and some peaks were shifted. XRD analysis determined that the peaks representing CA and pCNPs were collectively obtained in CA-CNPs. As per DLS analysis, the particle size, PDI and ζ-potential of the CA-CNPs were 259 nm, 0.284 and 30.4 mV. Further, the CA-CNPs were non-cytotoxic on Hep3B cells at the maximum tested concentration of 500 μg/mL. The viability at 500 μg/mL of CA-CNPs was two-fold higher than 500 μg/mL of pCNPs. Also, the pCNPs were not hemolytic and therefore could not have played a role in the increase of viability after treatment with CA-CNPs, which indicates that CA posed a major role in increased viability of Hep3B cells. As per quantitative PCR (qPCR), the upregulated gene expressions of PI3K, Akt, mTORC2, cMyc, Fibronectin, hVPS34, Slug and ZEB1 and the downregulated expression of the tumor suppressor PTEN indicates that PI3K/Akt/mTOR pathway mediated the induction of epithelial-to-mesenchymal transition (EMT) in response to CA-CNPs treatment on Hep3B cells.

Safety of Zein Nanoparticles on Human Innate Immunity and Inflammation

In recent years, natural polymers have attracted great interest for the development of release systems for vaccine formulations and drug delivery. Zein, a hydrophobic proline-rich protein mixture obtained from maize, is one of the most widely used polymers, very promising for applications in tissue engineering and the parenteral delivery of bioactive agents. Still, we have a limited understanding of the interaction between zein particles and the human immune system, in particular innate immunity/inflammation, which is the first line of defense of our body. Assessing the immune safety of nanoparticles is of central importance for ensuring that nano-formulations for medical use do not cause adverse effects on human health. Here, we evaluated the capacity of zein nanoparticles to induce/modulate the innate/inflammatory response, the development of innate memory, and the macrophage polarization by using reliable in vitro systems based on human primary monocytes and monocyte-derived macrophages. We observed that zein nanoparticles do not influence any of these aspects of the innate immune/inflammatory response, suggesting its safety and its potential efficiency as a nanocarrier for drug or antigen delivery.

Advances in Chitosan Derivatives: Preparation, Properties and Applications in Pharmacy and Medicine

Chitosan (CS) derivatives have been extensively investigated to enhance the physicochemical and biological properties of CS, such as its solubility, biocompatibility, and bioactivity, which are required in various areas of pharmacy and medicine. The present work emphasizes the ongoing research and development in this field, suggesting that the further exploration of CS derivatives could lead to innovative solutions that benefit society. The physicochemical properties, biological activities, methods of preparation, advantages, limitations, intended application areas, and realized practical implementations of particular CS derivatives are summarized and discussed herein. Despite the numerous promising attributes of CS derivatives as reported in this paper, however, challenges like target selectivity, standardization (purity, chitosan structural variability), and cost-effectiveness still need addressing for widespread implementation, especially in drug delivery. Therefore, basic research studies still prevail in CS drug delivery systems. However, for specific applications such as wound healing and tissue engineering, implementations of CS derivatives in practice are found to be more frequent. To obtain a more complex view of the topic, information from the scientific papers reviewed is supplemented with information from actual patents and clinical studies. Both basic research advances and the most successful and important medical implementations of CS derivatives are discussed concerning further challenges and future perspectives.

A new mechanism of thyroid hormone receptor β agonists ameliorating nonalcoholic steatohepatitis by inhibiting intestinal lipid absorption via remodeling bile acid profiles

Excessive dietary calories lead to systemic metabolic disorders, disturb hepatic lipid metabolism, and aggravate nonalcoholic steatohepatitis (NASH). Bile acids (BAs) play key roles in regulating nutrition absorption and systemic energy homeostasis. Resmetirom is a selective thyroid hormone receptor β (THRβ) agonist and the first approved drug for NASH treatment. It is well known that the THRβ activation could promote intrahepatic lipid catabolism and improve mitochondrial function, however, its effects on intestinal lipid absorption and BA compositions remain unknown. In the present study, the choline-deficient, L-amino acid defined, high-fat diet (CDAHFD) and high-fat diet plus CCl4 (HFD+CCl4)-induced NASH mice were used to evaluate the effects of resmetirom on lipid and BA composition. We showed that resmetirom administration (10 mg·kg-1·d-1, i.g.) significantly altered hepatic lipid composition, especially reduced the C18:2 fatty acyl chain-containing triglyceride (TG) and phosphatidylcholine (PC) in the two NASH mouse models, suggesting that THRβ activation inhibited intestinal lipid absorption since C18:2 fatty acid could be obtained only from diet. Targeted analysis of BAs showed that resmetirom treatment markedly reduced the hepatic and intestinal 12-OH to non-12-OH BAs ratio by suppressing cytochrome P450 8B1 (CYP8B1) expression in both NASH mouse models. The direct inhibition by resmetirom on intestinal lipid absorption was further verified by the BODIPY gavage and the oral fat tolerance test. In addition, disturbance of the altered BA profiles by exogenous cholic acid (CA) supplementation abolished the inhibitory effects of resmetirom on intestinal lipid absorption in both normal and CDAHFD-fed mice, suggesting that resmetirom inhibited intestinal lipid absorption by reducing 12-OH BAs content. In conclusion, we discovered a novel mechanism of THRβ agonists on NASH treatment by inhibiting intestinal lipid absorption through remodeling BAs composition, which highlights the multiple regulation of THRβ activation on lipid metabolism and extends the current knowledge on the action mechanisms of THRβ agonists in NASH treatment.

Exploiting the bile acid binding protein as transporter of a Cholic Acid/Mirin bioconjugate for potential applications in liver cancer therapy

Bioconjugation is one of the most promising strategies to improve drug delivery, especially in cancer therapy. Biomolecules such as bile acids (BAs) have been intensively explored as carriers, due to their peculiar physicochemical properties and biocompatibility. BAs trafficking is regulated by intracellular lipid-binding proteins and their transport in the liver can be studied using chicken liver Bile Acid-Binding Proteins (cL-BABPs) as a reference model. Therefore, we conceived the idea of developing a BA-conjugate with Mirin, an exonuclease inhibitor of Mre11 endowed with different anticancer activities, to direct its transport to the liver. Following computational analysis of various BAs in complex with cL-BABP, we identified cholic acid (CA) as the most promising candidate as carrier, leading to the synthesis of a novel bioconjugate named CA-M11. As predicted by computational data and confirmed by X-ray crystallographic studies, CA-M11 was able to accommodate into the binding pocket of BABP. Hence, it can enter BAs trafficking in the hepatic compartment and here release Mirin. The effect of CA-M11, evaluated in combination with varying concentrations of Doxorubicin on HepG2 cell line, demonstrated a significant increase in cell mortality compared to the use of the cytotoxic drug or Mirin alone, thus highlighting chemo-sensitizing properties. The promising results regarding plasma stability for CA-M11 validate its potential as a valuable agent or adjuvant for hepatic cancer therapy.

Tauroursodeoxycholic Acid Improves Nonalcoholic Fatty Liver Disease by Regulating Gut Microbiota and Bile Acid Metabolism

Tauroursodeoxycholic acid (TUDCA) is a synthetic bile salt that has demonstrated efficacy in the management of hepatobiliary disorders. However, its specific mechanism of action in preventing and treating nonalcoholic fatty liver disease (NAFLD) remains incompletely understood. This research revealed that TUDCA treatment can reduce obesity and hepatic lipid buildup, enhance intestinal barrier function and microbial balance, and increase the presence of Allobaculum and Bifidobacterium in NAFLD mouse models. TUDCA can influence the activity of farnesoid X receptor (FXR) and cholesterol 7α-hydroxylase (CYP7A1), resulting in higher hepatic bile acid levels and increased expression of sodium taurocholate cotransporting polypeptide (NTCP), leading to elevated concentrations of liver-bound bile acids in mice. Furthermore, TUDCA can inhibit the expression of FXR and fatty acid transport protein 5 (FATP5), thereby reducing fatty acid absorption and hepatic lipid accumulation. This investigation provides new insights into the potential of TUDCA for preventing and treating NAFLD.

Bile salt integrated cerasomes: A potential nanocarrier for enhancement of the oral bioavailability of idarubicin hydrochloride

Cerasomes are a modified form of liposomes containing both inorganic and organic parts and due to their strong polyorganosiloxane surface have remarkably high morphological stability and provide easier functionalization compared with conventional liposomes. To investigate the potential of these nanocarriers for oral delivery, bile salt integrated cerasomes (named bilocerasomes) encapsulating idarubicin hydrochloride (IDA) were prepared and characterized. The optimum formulation showed excellent stability in the simulated gastrointestinal fluids as well as under storage conditions. The oral pharmacokinetics of the IDA solution, empty nanocarrier + drug solution, and IDA-loaded bilocerasome were evaluated. The nanoformulation significantly increased the area under the drug concentration-time curve and the mean residence time (∼14.3- and 9-fold, respectively). The results obtained from cell uptake and chylomicron flow blocking approach revealed that bilocerasomes are absorbed into the intestinal cells via a clathrin/caveolin-independent endocytosis pathway and transported to the systemic circulation extensively via the intestinal lymphatic vessels. Considering the high stability of the prepared bilocerasome, noticeable participation of lymphatic transport in its systemic absorption and marked enhancement in the oral absorption of IDA, bilocerasomes can be introduced as a capable carrier for improving the oral bioavailability of drugs, particularly those that hepatic first-pass metabolism seriously limits their oral absorption.

Specific intermolecular interaction with sodium glycocholate generates the co-amorphous system showing higher physical stability and aqueous solubility of Y5 receptor antagonist of neuropeptide Y, a brick dust molecule

Drugs with poor water and lipid solubility are termed "brick dust." We previously successfully developed a co-amorphous system of a novel neuropeptide Y5 receptor antagonist (AntiY5R), a brick dust molecule, using sodium taurocholate (NaTC) as a co-former. However, the maximum improvement in AntiY5R dissolution by the co-amorphous system was only approximately 10 times greater than that of the crystals. Therefore, in the current study, other bile salts, including sodium cholate (NaC), sodium chenodeoxycholate (NaCC), and sodium glycocholate (NaGC), were examined as co-formers to further improve AntiY5R dissolution. NaC, NaCC, and NaGC have glass transition temperatures above 150°C. All three co-amorphous systems prepared successfully retained the amorphous form of AntiY5R for 3 months at 40°C, but the co-amorphous system with NaGC (AntiY5R-NaGC; 1:9 molar ratio) provided the highest improvement in AntiY5R dissolution, which was approximately 50 times greater than that of the crystals. Possible intermolecular interactions via the glycine moiety of NaGC more than the other bile salts would contribute to the highest dissolution enhancement with AntiY5R-NaGC. Thus, NaGC would be a promising co-former for formulating stable co-amorphous systems to enhance the dissolution behavior of brick dust molecules.

Association between Fecal Bile Acids and Levodopa Response in Patients with Parkinson's Disease

Levodopa is the mainstay of treatments for Parkinson's disease (PD), but large heterogeneity exists in patient response. Increasing evidence implicates bile acids (BAs) involved in the pathogenesis of PD. Furthermore, BAs have also participated in drug bioavailability. However, the impact of BAs on levodopa response (LR) has not been investigated. This study evaluated the association between fecal BAs and LR. Levodopa challenge test (LCT) was conducted in 92 PD patients to assess LR. A total of 36 fecal BAs and plasma levodopa concentrations were detected using LC-MS/MS. The difference of BAs between subgroups with bottom and top 30% LR were analyzed and fecal samples from the two groups were collected for metagenomic shotgun analysis. No fecal BAs were significantly correlated with LR, except for chenodeoxycholic acid-3-β-D-glucuronide (CDCA-3-β-glucuronide, R = -0.228, p-value = 0.039). We found no significant difference in BAs between subgroups with bottom and top 30% LR. What is more, no significant changes in bacterial species composition related to bile acids metabolism or in the proportional representation of genes encoding known bile acids enzymes were observed between the groups. Overall, our data do not support an association between fecal BAs and levodopa response in PD patients. More precise macro-metabolomic approaches are needed to reveal the potential association between gut microbial interactions and the treatment effect of levodopa.

Exploring molecular fingerprints of different drugs having bile interaction: a stepping stone towards better drug delivery

Bile acids are amphiphilic substances produced naturally in humans. In the context of drug delivery and dosage form design, it is critical to understand whether a drug interacts with bile inside the gastrointestinal (GI) tract or not. This study focuses on the identification of structural fingerprints/features important for bile interaction. Molecular modelling methods such as Bayesian classification and recursive partitioning (RP) studies are executed to find important fingerprints/features for the bile interaction. For the Bayesian classification study, the ROC score of 0.837 and 0.950 are found for the training set and the test set compounds, respectively. The fluorine-containing aliphatic/aromatic group, the branched chain of the alkyl group containing hydroxyl moiety and the phenothiazine ring etc. are identified as good fingerprints having a positive contribution towards bile interactions, whereas, the bad fingerprints such as free carboxylate group, purine, and pyrimidine ring etc. have a negative contribution towards bile interactions. The best tree (tree ID: 1) from the RP study classifies the bile interacting or non-interacting compounds with a ROC score of 0.941 for the training and 0.875 for the test set. Additionally, SARpy and QSAR-Co analyses are also been performed to classify compounds as bile interacting/non-interacting. Moreover, forty-six recently FDA-approved drugs have been screened by the developed SARpy and QSAR-Co models to assess their bile interaction properties. Overall, this attempt may facilitate the researchers to identify bile interacting/non-interacting molecules in a faster way and help in the design of formulations and target-specific drug development.

Engineered nanomicelles targeting proliferation and angiogenesis inhibit tumour progression by impairing the synthesis of ceramide-1-phosphate

Tumour cells secrete various proangiogenic factors like VEGF, PDGF, and EGF that result in the formation of highly vascularized tumours with an immunosuppressive tumour microenvironment. As tumour growth and metastasis are highly dependent on angiogenesis, targeting tumour vasculature along with rapidly dividing tumour cells is a potential approach for cancer treatment. Here, we specifically engineered sub-100 sized nanomicelles (DTX-CA4 NMs) targeting proliferation and angiogenesis using an esterase-sensitive phosphocholine-tethered docetaxel conjugate of lithocholic acid (LCA) (PC-LCA-DTX) and a poly(ethylene glycol) (PEG) derivative of an LCA-combretastatin A4 conjugate (PEG-LCA-CA4). DTX-CA4 NMs effectively inhibit the tumour growth in syngeneic (CT26) and xenograft (HCT116) colorectal cancer models, inhibit tumour recurrence, and enhance the percentage survival in comparison with individual drug-loaded NMs. DTX-CA4 NMs enhance the T cell-mediated anti-tumour immune response and DTX-CA4 NMs in combination with an immune checkpoint inhibitor, anti-PDL1 antibody, enhance the anti-tumour response. We additionally showed that DTX-CA4 NMs effectively attenuate the production of ceramide-1-phosphate, a key metabolite of the sphingolipid pathway, by downregulating the expression of ceramide kinase at both transcriptional and translational levels. Therefore, this study presents the engineering of effective DTX-CA4 NMs for targeting the tumour microenvironment that can be explored further for clinical applications.

Emerging Trends in Bilosomes as Therapeutic Drug Delivery Systems

In recent years, there has been a notable surge in the utilization of stabilized bile acid liposomes, chemical conjugates, complexes, mixed micelles, and other drug delivery systems derived from bile acids, often referred to as bilosomes. The molecular structure and interactions of these amphiphilic compounds provide a distinctive and captivating subject for investigation. The enhanced stability of new generation bilosomes inside the gastrointestinal system results in the prevention of drug degradation and an improvement in mucosal penetration. These characteristics render bilosomes to be a prospective nanocarrier for pharmaceutical administration, prompting researchers to investigate their potential in other domains. This review paper discusses bilosomes that have emerged as a viable modality in the realm of drug delivery and have significant promise for use across several domains. Moreover, this underscores the need for additional investigation and advancement in order to comprehensively comprehend the prospective uses of bilosomes and their effectiveness in the field of pharmaceutical administration. This review study explores the current scholarly attention on bilosomes as prospective carriers for drug delivery. Therapeutic areas where bilosomes have shown outstanding performance in terms of drug delivery are outlined in the graphical abstract.

Evaluation of Silybin Nanoparticles against Liver Damage in Murine Schistosomiasis mansoni Infection

Silybin (SIB) is a hepatoprotective drug known for its poor oral bioavailability, attributed to its classification as a class IV drug with significant metabolism during the first-pass effect. This study explored the potential of solid lipid nanoparticles with (SLN-SIB-U) or without (SLN-SIB) ursodeoxycholic acid and polymeric nanoparticles (PN-SIB) as delivery systems for SIB. The efficacy of these nanosystems was assessed through in vitro studies using the GRX and Caco-2 cell lines for permeability and proliferation assays, respectively, as well as in vivo experiments employing a murine model of Schistosomiasis mansoni infection in BALB/c mice. The mean diameter and encapsulation efficiency of the nanosystems were as follows: SLN-SIB (252.8 ± 4.4 nm, 90.28 ± 2.2%), SLN-SIB-U (252.9 ± 14.4 nm, 77.05 ± 2.8%), and PN-SIB (241.8 ± 4.1 nm, 98.0 ± 0.2%). In the proliferation assay with the GRX cell line, SLN-SIB and SLN-SIB-U exhibited inhibitory effects of 43.09 ± 5.74% and 38.78 ± 3.78%, respectively, compared to PN-SIB, which showed no inhibitory effect. Moreover, SLN-SIB-U demonstrated a greater apparent permeability coefficient (25.82 ± 2.2) than PN-SIB (20.76 ± 0.1), which was twice as high as that of SLN-SIB (11.32 ± 4.6) and pure SIB (11.28 ± 0.2). These findings suggest that solid lipid nanosystems hold promise for further in vivo investigations. In the murine model of acute-phase Schistosomiasis mansoni infection, both SLN-SIB and SLN-SIB-U displayed hepatoprotective effects, as evidenced by lower alanine amino transferase values (22.89 ± 1.6 and 23.93 ± 2.4 U/L, respectively) than those in control groups I (29.55 ± 0.7 U/L) and I+SIB (34.29 ± 0.3 U/L). Among the prepared nanosystems, SLN-SIB-U emerges as a promising candidate for enhancing the pharmacokinetic properties of SIB.

Engineering aspects of lipid-based delivery systems: In vivo gene delivery, safety criteria, and translation strategies

Defects in the genome cause genetic diseases and can be treated with gene therapy. Due to the limitations encountered in gene delivery, lipid-based supramolecular colloidal materials have emerged as promising gene carrier systems. In their non-functionalized form, lipid nanoparticles often demonstrate lower transgene expression efficiency, leading to suboptimal therapeutic outcomes, specifically through reduced percentages of cells expressing the transgene. Due to chemically active substituents, the engineering of delivery systems for genetic drugs with specific chemical ligands steps forward as an innovative strategy to tackle the drawbacks and enhance their therapeutic efficacy. Despite intense investigations into functionalization strategies, the clinical outcome of such therapies still needs to be improved. Here, we highlight and comprehensively review engineering aspects for functionalizing lipid-based delivery systems and their therapeutic efficacy for developing novel genetic cargoes to provide a full snapshot of the translation from the bench to the clinics. We outline existing challenges in the delivery and internalization processes and narrate recent advances in the functionalization of lipid-based delivery systems for nucleic acids to enhance their therapeutic efficacy and safety. Moreover, we address clinical trials using these vectors to expand their clinical use and principal safety concerns.

Microfluidic gut-axis-on-a-chip models for pharmacokinetic-based disease models

The low success rate of new drugs transitioning from animal testing to human clinical trials necessitates the development of more accurate and representative in vitro models. Recent advances in multi-organ-on-a-chip technology offer promising avenues for studying complex organ-organ interactions. Gut-liver-on-a-chip systems hold particular promise for mimicking the intricate interplay between the gut and liver, which play crucial roles in nutrient absorption, drug metabolism, detoxification, and immune response. Here, we discuss the key components of the gut-liver axis, including the gut epithelium, liver cells, gut microbiota, and their roles in the organ functions. We then explore the potential of gut-liver-on-a-chip models to replicate the intricate interactions between the two organs for pharmacokinetic studies and their expansion to more complicated multi-organ models. Finally, we provide perspectives and future directions for developing more physiologically relevant gut-liver-axis models for more efficient drug development, studying liver diseases, and personalizing treatment strategies.

Engineered nanomicelles inhibit the tumour progression via abrogating the prostaglandin-mediated immunosuppression

Cancer treatment is challenged due to immunosuppressive inflammatory tumour microenvironment (TME) caused by infiltration of tumour-promoting and inhibition of tumour-inhibiting immune cells. Here, we report the engineering of chimeric nanomicelles (NMs) targeting the cell proliferation using docetaxel (DTX) and inflammation using dexamethasone (DEX) that alters the immunosuppressive TME. We show that a combination of phospholipid-DTX conjugate and PEGylated-lipid-DEX conjugate can self-assemble to form sub-100 nm chimeric NMs (DTX-DEX NMs). Anti-cancer activities against syngeneic and xenograft mouse models showed that the DTX-DEX NMs are more effective in tumour regression, enhance the survival of mice over other treatment modes, and alter the tumour stroma. DTX-DEX NMs cause a significant reduction in myeloid-derived suppressor cells, alter the polarization of macrophages, and enhance the accumulation of cytotoxic CD4+ and CD8+ T cells in tumour tissues, along with alterations in cytokine expression. We further demonstrated that these DTX-DEX NMs inhibit the synthesis of prostaglandins, especially PGE2, by targeting the cyclooxygenase 2 that is partly responsible for immunosuppressive TME. Therefore, this study presents, for the first time, the engineering of lithocholic acid-derived chimeric NMs that affect the prostaglandin pathway, alter the TME, and mitigate tumour progression with enhanced mice survival.

Influence of Bile Acids on Clindamycin Hydrochloride Skin Permeability: In Vitro and In Silico Preliminary Study

BACKGROUND AND OBJECTIVE

Topical clindamycin formulations are widely used in clinical practice, but poor bioavailability and restricted skin penetration considerably limit their therapeutic efficacy. Penetration enhancement represents a promising and rational strategy to overcome the drawbacks of conventional topical pharmaceutical formulations. We aim to assess the influence of cholic acid (CA) and deoxycholic acid (DCA) on the permeability of clindamycin hydrochloride by performing the in vitro skin parallel artificial membrane permeability assay (skin-PAMPA) at two relevant pH values (5.5 and 6.5) and the interactions of tested substances with skin ATP-binding cassette (ABC) transporters in silico.

METHODS

After the incubation period, the clindamycin hydrochloride concentrations in both compartments were determined spectrophotometrically, and the apparent permeability coefficients (Papp) were calculated. Vienna LiverTox web service was used to predict the interactions of clindamycin and bile acids with potential drug transporters located in human skin.

RESULTS

Both CA and DCA at the highest studied concentration of 100 μM in the tested solutions increased the skin-PAMPA membrane permeability of clindamycin hydrochloride. This effect was more pronounced for CA and at a higher studied pH value of 6.5, which is characteristic of most dermatological indications treated with topical clindamycin preparations. Clindamycin transport may also be mediated by ABC transporters located in skin and facilitated in the presence of bile acids.

CONCLUSIONS

The results of this study provide a solid foundation for further research directed at the improvement of topical formulations using bile acids as penetration-enhancing excipients, as well as the therapeutic efficacy of clindamycin hydrochloride.

Bile salt-enriched vs. non-enriched nanoparticles: comparison of their physicochemical characteristics and release pattern

Bile salts were first used in the preparation of nanoparticles due to their stabilizing effects. As time went by, they attracted much attention and were increasingly employed in fabricating nanoparticles. It is well accepted that the physicochemical properties of nanoparticles are influential factors in their permeation, distribution, elimination and degree of effectiveness as well as toxicity. The review of articles shows that the use of bile salts in the structure of nanocarriers may cause significant changes in their physicochemical properties. Hence, having information about the effect of bile salts on the properties of nanoparticles could be valuable in the design of optimal carriers. Herein, we review studies in which bile salts were used in preparing liposomes, niosomes and other nanocarriers. Furthermore, the effects of bile salts on entrapment efficiency, particle size, polydispersity index, zeta potential, release profile and stability of nanoparticles are pointed out. Finally, we debate how to take advantage of bile salts potential for preparing desirable nanocarriers.

In-silico and in-vitro evaluation of antifungal bioactive compounds from Streptomyces sp. strain 130 against Aspergillus flavus

Streptomyces spp. are considered excellent reservoirs of natural bioactive compounds. The study evaluated the bioactive potential of secondary metabolites from Streptomyces sp. strain 130 through PKS-I and NRPS gene-clusters screening. GC-MS analysis was done for metabolic profiling of bioactive compounds from strain 130 in the next set of experiments. Identified antifungal compounds underwent ADMET analyses to screen their toxicity. All compounds' molecular docking was done with the structural gene products of the aflatoxin biosynthetic pathway of Aspergillus flavus. MD simulations were utilized to evaluate the stability of protein-ligand complexes under physiological conditions. Based on the in-silico studies, compound 2,4-di-tert butyl-phenol (DTBP) was selected for in-vitro studies against Aspergillus flavus. Simultaneously, bioactive compounds were extracted from strain 130 in two different solvents (ethyl-acetate and methanol) and used for similar assays. The MIC value of DTBP was found to be 314 µg/mL, whereas in ethyl-acetate extract and methanol-extract, it was 250 and 350 µg/mL, respectively. A mycelium growth assay was done to analyze the effect of compounds/extracts on the mycelium formation of Aspergillus flavus. In agar diffusion assay, zone of inhibitions in DTBP, ethyl-acetate extract, and methanol extract were observed with diameters of 11.3, 13.3, and 7.6 mm, respectively. In the growth curve assay, treated samples have delayed the growth of fungi, which signified that the compounds have a fungistatic nature. Spot assay has determined the fungal sensitivity to a sub-minimum inhibitory concentration of antifungal compounds. The study's results suggested that DTBP can be exploited for antifungal-drug development.

Enhanced Oral Bioavailability of Progesterone in Bilosome Formulation: Fabrication, Statistical Optimization, and Pharmacokinetic Study

Progesterone, a female sex steroid hormone, is highly lipophilic, leading to poor oral bioavailability. This study aimed to develop a progesterone bilosome system to enhance its oral bioavailability and retain it longer in the body. Progesterone vesicles were formulated with bile salts by thin film hydration method to prevent enzymatic and bile acid degradation. The Box-Behnken experimental design was used to statistically optimize progesterone bilosomes by checking the effect of phosphatidylcholine, cholesterol, and sodium deoxycholate on vesicle size, zeta potential, and entrapment efficiency. The optimum batch showed 239.5 nm vesicle size, -28.2 mV zeta potential and 84.08% entrapment efficiency, respectively, which were significantly affected by phosphatidylcholine and cholesterol concentration. The successful incorporation of progesterone in the system was evident from ATR-FTIR analysis that revealed no sharp progesterone peaks in bilosomes. TEM analysis confirmed the spherical structure and uniform bilosome vesicles. Furthermore, the in vitro drug release of progesterone bilosomes revealed a sustained pattern exhibiting 90% drug release in 48 h. The pharmacokinetic study in female ovariectomized Wistar rats confirmed the 4.287- and 9.75-fold enhanced oral bioavailability of the progesterone bilosomes than marketed capsules and progesterone API, respectively. Therefore, progesterone bilosome formulation can be further explored for improved oral administration in chronic treatments.

Exploiting Apical Sodium-Dependent Bile Acid Transporter (ASBT)-Mediated Endocytosis with Multi-Functional Deoxycholic Acid Grafted Alginate Amide Nanoparticles as an Oral Insulin Delivery System

OBJECTIVE

Oral administration of insulin is a potential candidate for managing diabetes. However, it is obstructed by the gastrointestinal tract barriers resulting in negligible oral bioavailability.

METHODS

This investigation presents a novel nanocarrier platform designed to address these challenges. In this regard, the process involved amination of sodium alginate by ethylene diamine, followed by its conjugation with deoxycholic acid.

RESULTS

The resulting DCA@Alg@INS nanocarrier revealed a significantly high insulin loading content of 63.6 ± 1.03% and encapsulation efficiency of 87.6 ± 3.84%, with a particle size of 206 nm and zeta potentials of -3 mV. In vitro studies showed sustained and pH-dependent release profiles of insulin from nanoparticles. In vitro cellular studies, confocal laser scanning microscopy and flow cytometry analysis confirmed the successful attachment and internalization of DCA@Alg@INS nanoparticles in Caco-2 cells. Furthermore, the DCA@Alg@INS demonstrated a superior capacity for cellular uptake and permeability coefficient relative to the insulin solution, exhibiting sixfold and 4.94-fold enhancement, respectively. According to the uptake mechanism studies, the results indicated that DCA@Alg@INS was mostly transported through an energy-dependent active pathway since the uptake of DCA@Alg@INS by cells was significantly reduced in the presence of NaN3 by ~ 92% and at a low temperature of 4°C by ~ 94%.

CONCLUSIONS

Given the significance of administering insulin through oral route, deoxycholic acid-modified alginate nanoparticles present a viable option to surmount various obstacles presented by the gastrointestinal.

Novel polysaccharides-bile acid-cyclodextrin gel systems and effects on cellular viability and bioenergetic parameters

Aim: The novel hydrogel systems made from sodium alginate, pectin, beta-cyclodextrin and deoxycholic acid (DCA) were proposed as potential drug-delivery matrices. Materials & methods: To ensure biocompatibility, rheological parameters were examined and hydrogels' effects on bioenergetic parameters and cellular viability on murine hepatic, and muscle and pancreatic beta cells. Results & conclusion: All hydrogels show non-Newtonian, shear thinning behavior. Cells displayed various oxygen-dependent viability patterns, with the bile acid overall adversely affecting their biological activities. All cells performed best under normoxia, with pancreatic beta cells displaying the most profound oxygen-dependent viability behavior. The cells tolerated the addition of a moderate concentration of beta-cyclodextrin to the polymer matrix.

Integrating the gut microbiome and pharmacology

The gut microbiome harbors trillions of organisms that contribute to human health and disease. These bacteria can also affect the properties of medical drugs used to treat these diseases, and drugs, in turn, can reshape the microbiome. Research addressing interdependent microbiome-host-drug interactions thus has broad impact. In this Review, we discuss these interactions from the perspective of drug bioavailability, absorption, metabolism, excretion, toxicity, and drug-mediated microbiome modulation. We survey approaches that aim to uncover the mechanisms underlying these effects and opportunities to translate this knowledge into new strategies to improve the development, administration, and monitoring of medical drugs.

Microbial metabolism marvels: a comprehensive review of microbial drug transformation capabilities

This comprehensive review elucidates the pivotal role of microbes in drug metabolism, synthesizing insights from an exhaustive analysis of over two hundred papers. Employing a structural classification system grounded in drug atom involvement, the review categorizes the microbiome-mediated drug-metabolizing capabilities of over 80 drugs. Additionally, it compiles pharmacodynamic and enzymatic details related to these reactions, striving to include information on encoding genes and specific involved microorganisms. Bridging biochemistry, pharmacology, genetics, and microbiology, this review not only serves to consolidate diverse research fields but also highlights the potential impact of microbial drug metabolism on future drug design and in silico studies. With a visionary outlook, it also lays the groundwork for personalized medicine interventions, emphasizing the importance of interdisciplinary collaboration for advancing drug development and enhancing therapeutic strategies.

Enhancement of Oral Bioavailability of Protein and Peptide by Polysaccharide-based Nanoparticles

Oral drug delivery is a prevalent and cost-effective method due to its advantages, such as increased drug absorption surface area and improved patient compliance. However, delivering proteins and peptides orally remains a challenge due to their vulnerability to degradation by digestive enzymes, stomach acids, and limited intestinal membrane permeability, resulting in poor bioavailability. The use of nanotechnology has emerged as a promising solution to enhance the bioavailability of these vital therapeutic agents. Polymeric NPs, made from natural or synthetic polymers, are commonly used. Natural polysaccharides, such as alginate, chitosan, dextran, starch, pectin, etc., have gained preference due to their biodegradability, biocompatibility, and versatility in encapsulating various drug types. Their hydrophobic-hydrophilic properties can be tailored to suit different drug molecules.

Nanocarriers transport across the gastrointestinal barriers: The contribution to oral bioavailability via blood circulation and lymphatic pathway

Oral administration is the preferred route of drug delivery in clinical practice due to its noninvasiveness, safety, convenience, and high patient compliance. The gastrointestinal tract (GIT) plays a crucial role in facilitating the targeted delivery of oral drugs. However, the GIT presents multiple barriers that impede drug absorption, including the gastric barrier in the stomach and the mucus and epithelial barriers in the intestine. In recent decades, nanotechnology has emerged as a promising approach for overcoming these challenges by utilizing nanocarrier-based drug delivery systems such as liposomes, micelles, polymeric nanoparticles, solid lipid nanoparticles, and inorganic nanoparticles. Encapsulating drugs within nanocarriers not only protects them from degradation but also enhances their transport and absorption across the GIT, ultimately improving oral bioavailability. The aim of this review is to elucidate the mechanisms underlying nanocarrier-mediated transportation across the GIT into systemic circulation via both the blood circulation and lymphatic pathway.

Unveiling the Role of Nonionic Surfactants in Enhancing Cefotaxime Drug Solubility: A UV-Visible Spectroscopic Investigation in Single and Mixed Micellar Formulations

This study reports the interfacial phenomenon of cefotaxime in combination with nonionic surfactants, Triton X-100 (TX-100) and Tween-80 (TW-80), and their mixed micellar formulations. Cefotaxime was enclosed in a micellar system to improve its solubility and effectiveness. TX-100 and TW-80 were used in an amphiphilic self-assembly process to create the micellar formulation. The effect of the addition of TX-100, a nonionic surfactant, on the ability of TW-80 to solubilize the drug was examined. The values of the critical micelle concentration (CMC) were determined via UV-Visible spectroscopy. Gibbs free energies (ΔGp and ΔGb), the partition coefficient (Kx), and the binding constant (Kb) were also computed. In a single micellar system, the partition coefficient (Kx) was found to be 33.78 × 106 and 2.78 × 106 in the presence of TX-100 and TW-80, respectively. In a mixed micellar system, the value of the partition coefficient for the CEF/TW-80 system is maximum (5.48 × 106) in the presence of 0.0019 mM of TX-100, which shows that TX-100 significantly enhances the solubilizing power of micelles. It has been demonstrated that these surfactants are effective in enhancing the solubility and bioavailability of therapeutic compounds. This study elaborates on the physicochemical characteristics and solubilization of reactive drugs in single and mixed micellar media. This investigation, conducted in the presence of surfactants, shows a large contribution to the binding process via both hydrogen bonding and hydrophobic interactions.

Oral delivery of a host-directed antiviral, niclosamide, as a cholate-coated nanoformulation

Potentially significant drug candidates often face elimination from consideration due to the lack of an effective method for systemic delivery. The poor solubility of these candidates has posed a major obstacle for their development as oral pills or injectables. Niclosamide, a host-directed antiviral, is a good example. In this study, a nanoformulation technology that allows for the non-covalent formulation of niclosamide with cholic acids was developed. This formulation enables efficient systemic delivery through endocytosis and enterohepatic circulation of bile-acid-coated nanoparticles. The oral bioavailability of niclosamide-delivery nanoparticles (NDNs) was significantly enhanced to 38.3%, representing an eight-fold increase compared with pure niclosamide. Consequently, the plasma concentration of niclosamide for the NDN formulation reached 1179.6 ng/mL, which is 11 times higher than the therapeutic plasma level. This substantial increase in plasma level contributed to the complete resolution of clinical symptoms in animals infected with severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2). This nanoformulation not only provides an orally deliverable antiviral drug for SARS-CoV-2 with improved pharmaceutical bioavailability, but also offers a solution to the systemic delivery challenges faced by potentially significant drug candidates.

Tailoring the Self-Assembly of Steviol Glycoside Nanocarriers with Steroidal Amphiphiles

Bile salts are biosurfactants that can induce structure transformations in supramolecular nanoassemblies with conventional surfactants owing to their unique, planar amphiphilic character and the rigidity of their hydrophobic steroid skeleton. However, structural information about the association of bile salts and amphiphilic glycosides is lacking. In this work, we investigated the micelle structure of two anionic di- and trihydroxy bile salts [sodium deoxycholate (SDC) and sodium cholate (SC)] and a conventional anionic surfactant [sodium dodecyl sulfate (SDS)] in mixtures with a nonionic steviol glycoside [α-glucosyl stevia (Stevia-G)] and studied their potential as a nanocarrier system for two poorly water-soluble drugs (clotrimazole and ketoconazole). Decreased critical micelle concentrations determined from surface tension measurements demonstrate synergistic interactions between Stevia-G and SDS/SDC/SC in a decreasing order. Small-angle X-ray and neutron scattering, interpreted by a core-shell ellipsoid model, indicate that SDS and bile salts act differently on the mixed micelle structure. Compared with SDS/Stevia-G, bile salt/Stevia-G had a core-shell structure more similar to that of pure Stevia-G micelles. SDC and SDS had an increasing and decreasing influence, respectively, on the available molecular surface area in mixtures with Stevia-G on the micelle core but a similar influence on the micelle shell solvation number relative to that of their pure micellar structures. The number of bile salt hydroxyl groups was influential in determining the micelle stoichiometry: an increasing number of hydroxyl groups corresponded to decreasing bile salt aggregation numbers and a smaller hydrophobic micellar core. The core volume was the most important structural factor in explaining the drug solubilization capacity of the nanocarrier systems. Therefore, bile salt-steviol glycoside mixed micellar assemblies exhibit structure control mechanisms allowing the fine-tuning of their interior hydrophobic domains important for nanocarrier applications toward solubilization of poorly water-soluble drugs.

New insights into the pathogenesis of primary biliary cholangitis asymptomatic stage

Primary biliary cholangitis (PBC) is a chronic cholestatic progressive liver disease and one of the most important progressive cholangiopathies in adults. Damage to cholangiocytes triggers the development of intrahepatic cholestasis, which progresses to cirrhosis in the terminal stage of the disease. Accumulating data indicate that damage to biliary epithelial cells [(BECs), cholangiocytes] is most likely associated with the intracellular accumulation of bile acids, which have potent detergent properties and damaging effects on cell membranes. The mechanisms underlying uncontrolled bile acid intake into BECs in PBC are associated with pH change in the bile duct lumen, which is controlled by the bicarbonate (HCO3-) buffer system "biliary HCO3- umbrella". The impaired production and entry of HCO3- from BECs into the bile duct lumen is due to epigenetic changes in expression of the X-linked microRNA 506. Based on the growing body of knowledge on the molecular mechanisms of cholangiocyte damage in patients with PBC, we propose a hypothesis explaining the pathogenesis of the first morphologic (ductulopenia), immunologic (antimitochondrial autoantibodies) and clinical (weakness, malaise, rapid fatigue) signs of the disease in the asymptomatic stage. This review focuses on the consideration of these mechanisms.

Strategies to Enhance the Solubility and Bioavailability of Tocotrienols Using Self-Emulsifying Drug Delivery System

Tocotrienols have higher medicinal value, with multiple sources of evidence showing their biological properties as antioxidant, anti-inflammatory, and osteoprotective compounds. However, tocotrienol bioavailability presents an ongoing challenge in its translation into viable products. This is because tocotrienol oil is known to be a poorly water-soluble compound, making it difficult to be absorbed into the body and resulting in less effectiveness. With the potential and benefits of tocotrienol, new strategies to increase the bioavailability and efficacy of poorly absorbed tocotrienol are required when administered orally. One of the proposed formulation techniques was self-emulsification, which has proven its capacity to improve oral drug delivery of poorly water-soluble drugs by advancing the solubility and bioavailability of these active compounds. This review discusses the updated evidence on the bioavailability of tocotrienols formulated with self-emulsifying drug delivery systems (SEDDSs) from in vivo and human studies. In short, SEDDSs formulation enhances the solubility and passive permeability of tocotrienol, thus improving its oral bioavailability and biological actions. This increases its medicinal and commercial value. Furthermore, the self-emulsifying formulation presents a useful dosage form that is absorbed in vivo independent of dietary fats with consistent and enhanced levels of tocotrienol isomers. Therefore, a lipid-based formulation technique can provide an additional detailed understanding of the oral bioavailability of tocotrienols.

Synthesis of bile acid-thiadiazole conjugates as antibacterial and antioxidant agents

The synthesis, characterization, and antibacterial and antioxidant activity of thiadiazole-deoxycholic/lithocholic acid conjugates are described in this communication. The structures of the synthesised bile acid-thiadiazole conjugates were studied using 1H NMR, 13C NMR and FTIR. Compounds 4c (IC50; 15.34 ± 0.07 μM) and 5c (IC50; 13.45 ± 0.25 μM) demonstrated greater antioxidant activity than the reference compound ascorbic acid (IC50; 20.72 ± 1.02 μM) in DPPH assay. The most effective conjugates against P. vulgarise were 4c (IC50; 24 ± 2.3 μM), 4 g (IC50; 29 ± 2.5 μM), and 5c (IC50; 93 ± 3.6 μM), whereas the most effective conjugates against E. coli were 4e (IC50; 55 ± 2.1 μM) and 4f (IC50; 52 ± 3.5 μM). Conjugates 4c and 5c were the most effective against B. megaterium of all the synthesised conjugates, with IC50 values of 15 ± 1.08 and 20 ± 1.1 μM, respectively. Thus, a large library of compounds derived from bile acid can be easily synthesised for extensive structure-activity relationship studies in order to identify the most appropriate antibacterial agents and antioxidant activity.

Breaking barriers: bilosomes gel potentials to pave the way for transdermal breast cancer treatment with Tamoxifen

OBJECTIVE

Breast cancer affects women globally, regardless of age or location. On the other hand, Tamoxifen (TXN), a class II biopharmaceutical drug is acting as a prophylactic/treating agent for women at risk of and/or with hormone receptor-positive breast cancer. However, its oral administration has life-threatening side effects, which have led researchers to investigate alternative delivery methods. One such method is transdermal drug delivery utilizing bile salts as penetration enhancers, aka Bilosomes.

METHODS

Bilosomes formulations were optimized statistically for the outcome of vesicle shape, size, and entrapment efficiency using two types of bile, i.e. sodium taurocholate and sodium cholate. These bilosomes were then loaded into HPMC base gel and further characterized for their morphology, drug content, pH, viscosity, spreadability and eventually ex-vivo skin penetration and deposition studies.

RESULTS

Findings showed that sodium cholate has superiority as a penetration enhancer over sodium taurocholate in terms of morphological characterizes, zeta potential, and cumulative amounts of tamoxifen permeated per unit area (15.13 ± 0.71 μg/cm2 and 6.51 ± 0.6 μg/cm2 respectively). In fact, bilosomes designed with sodium cholate provided around 9 folds of skin deposition compared to TXN non-bilosomal gel.

CONCLUSION

Bilosomes gels could be a promising option for locally delivering tamoxifen to the breast through the skin, offering an encouraging transdermal solution.

Bile salts enhance the susceptibility of the peach allergenic lipid transfer protein, Pru p 3, to in vitro gastrointestinal proteolysis

Sensitisation to the lipid transfer protein Pru p 3 is associated with severe allergic reactions to peach, the proteins stability being thought to play a role in its allergenicity. Lipid binding increases susceptibility of Pru p 3 to digestion and so the impact of bile salts on the in vitro gastrointestinal digestibility of Pru p 3 was investigated and digestion products mapped by SDS-PAGE and mass spectrometry. Bile salts enhanced the digestibility of Pru p 3 resulting in an ensemble of around 100 peptides spanning the protein's sequence which were linked by disulphide bonds into structures of ~ 5-6 kDa. IgE binding studies with a serum panel from peach allergic subjects showed digestion reduced, but did not abolish, the IgE reactivity of Pru p 3. These data show the importance of including bile salts in vitro digestion systems and emphasise the need to profile of digestion in a manner that allows identification of immunologically relevant disulphide-linked peptide aggregates.