Biomedical applications of functional hydrogels: Innovative developments, relevant clinical trials and advanced products.

Functional hydrogels are used for numerous biomedical applications such as tissue engineering, wound dressings, lubricants, contact lenses and advanced drug delivery systems. Most of them are based on synthetic or natural polymers forming a three-dimensional network that contains aqueous media. Among synthetic polymers, poly(meth)acrylates, polyethyleneglycols, poly(vinylalcohols), poly(vinylpyrrolidones), PLGA and poly(urethanes) are of high relevance, whereas natural polymers are mainly polysaccharides such as hyaluronic acid, alginate or chitosan and proteins such as albumin, collagen or elastin. In contrast to most synthetic polymers, natural polymers are biodegradable. Both synthetic and natural polymers are often chemically modified in order to improve or induce favorable properties and functions like high mechanical strength, stiffness, elasticity, high porosity, adhesive properties, in situ gelling properties, high water binding capacity or drug release controlling properties. Within this review we provide an overview about the broad spectrum of biomedical applications of functional hydrogels, summarize innovative approaches, discuss the concept of relevant functional hydrogels that are in clinical trials and highlight advanced products as examples for successful developments.

Microenvironment matters: In vitro 3D bone marrow niches differentially modulate survival, phenotype and drug responses of acute myeloid leukemia (AML) cells.

Acute myeloid leukemia (AML) is a deadly form of leukemia with ineffective traditional treatment and frequent chemoresistance-associated relapse. Personalized drug screening holds promise in identifying optimal regimen, nevertheless, primary AML cells undergo spontaneous apoptosis during cultures, invalidating the drug screening results. Here, we reconstitute a 3D osteogenic niche (3DON) mimicking that in bone marrow to support primary AML cell survival and phenotype maintenance in cultures. Specifically, 3DON derived from osteogenically differentiated mesenchymal stem cells (MSC) from healthy and AML donors are co-cultured with primary AML cells. The AML cells under the AML_3DON niche showed enhanced viability, reduced apoptosis and maintained CD33+ CD34-phenotype, associating with elevated secretion of anti-apoptotic cytokines in the AML_3DON niche. Moreover, AML cells under the AML_3DON niche exhibited low sensitivity to two FDA-approved chemotherapeutic drugs, further suggesting the physiological resemblance of the AML_3DON niche. Most interestingly, AML cells co-cultured with the healthy_3DON niche are highly sensitive to the same sample drugs. This study demonstrates the differential responses of AML cells towards leukemic and healthy bone marrow niches, suggesting the impact of native cancer cell niche in drug screening, and the potential of re-engineering healthy bone marrow niche in AML patients as chemotherapeutic adjuvants overcoming chemoresistance, respectively.

Photoswitchable dynamics and RNAi synergist with tailored interface and controlled release reprogramming tumor immunosuppressive niche.

Immunosuppressive tumor microenvironment (ITM) severely limited the efficacy of immunotherapy against triple-negative breast cancer (TNBC). Herein, Apt-LPR, a light-activatable photodynamic therapy (PDT)/RNAi immune synergy-enhancer was constructed by co-loading miR-34a and photosensitizers in cationic liposomes (in phase III clinical trial). Interestingly, the introduction of tumor-specific aptamers creates a special "Liposome-Aptamer-Target" interface, where the aptamers are initially in a "lying down" state but transform to "standing up" after target binding. The interfacing mechanism was elaborately revealed by computational and practical experiments. This unique interface endowed Apt-LPR with neutralized surface potential of cationic liposomes to reduce non-specific cytotoxicity, enhanced DNase resistance to protect aptamers, and preserved target-binding ability for selective drug delivery. Upon near-infrared irradiation, the generated reactive oxygen species would oxidize unsaturated phospholipids to destabilize both liposomes and lysosomes, realizing stepwise lysosomal escape of miR-34a for tumor cell apoptosis and downregulation of PD-L1 to suppress immune escape. Together, tumor-associated antigens released from PDT-damaged mitochondria and endoplasmic reticulum could activate the suppressive immune cells to establish an "immune hot" milieu. The collaborative immune-enhancing strategy effectively aroused systemic antitumor immunity and inhibited primary and distal tumor progression as well as lung metastasis in 4T1 xenografted mouse models. The photo-controlled drug release and specific tumor-targeting capabilities of Apt-LPR were also visualized in MDA-MB-231 xenografted zebrafish models. Therefore, this photoswitchable PDT/RNAi immune stimulator offered a powerful approach to reprogramming ITM and reinforcing cancer immunotherapy efficacy.

Manganese-coordinated nanoparticle with high drug-loading capacity and synergistic photo-/immuno-therapy for cancer treatments.

Stimulator of interferon genes (STING) agonists have shown promise in cancer treatment by stimulating the innate immune response, yet their clinical potential has been limited by inefficient cytosolic entry and unsatisfactory pharmacological activities. Moreover, aggressive tumors with "cold" and immunosuppressive microenvironments may not be effectively suppressed solely through innate immunotherapy. Herein, we propose a multifaceted immunostimulating nanoparticle (Mn-MC NP), which integrates manganese II (Mn2+) coordinated photosensitizers (chlorin e6, Ce6) and STING agonists (MSA-2) within a PEGylated nanostructure. In Mn-MC NPs, Ce6 exerts potent phototherapeutic effects, facilitating tumor ablation and inducing immunogenic cell death to elicit robust adaptive antitumor immunity. MSA-2 activates the STING pathway powered by Mn2+, thereby promoting innate antitumor immunity. The Mn-MC NPs feature a high drug-loading capacity (63.42 %) and directly ablate tumor tissue while synergistically boosting both adaptive and innate immune responses. In subsutaneous tumor mouse models, the Mn-MC NPs exhibit remarkable efficacy in not only eradicating primary tumors but also impeding the progression of distal and metastatic tumors through synergistic immunotherapy. Additionally, they contribute to preventing tumor recurrence by fostering long-term immunological memory. Our multifaceted immunostimulating nanoparticle holds significant potential for overcoming limitations associated with insufficient antitumor immunity and ineffective cancer treatment.

A natural adhesive-based nanomedicine initiates photothermal-directed in situ immunotherapy with durability and maintenance.

Tumor immunotherapies have emerged as a promising frontier in the realm of cancer treatment. However, challenges persist in achieving localized, durable immunostimulation while counteracting the tumor's immunosuppressive environment. Here, we develop a natural mussel foot protein-based nanomedicine with spatiotemporal control for tumor immunotherapy. In this nanomedicine, an immunoadjuvant prodrug and a photosensitizer are integrated, which is driven by their dynamic bonding and non-covalent assembling with the protein carrier. Harnessing the protein carrier's bioadhesion, this nanomedicine achieves a drug co-delivery with spatiotemporal precision, by which it not only promotes tumor photothermal ablation but also broadens tumor antigen repertoire, facilitating in situ immunotherapy with durability and maintenance. This nanomedicine also modulates the tumor microenvironment to overcome immunosuppression, thereby amplifying antitumor responses against tumor progression. Our strategy underscores a mussel foot protein-derived design philosophy of drug delivery aimed at refining combinatorial immunotherapy, offering insights into leveraging natural proteins for cancer treatment.

A single-chain fab derived drug conjugate for HER2 specific delivery.

Despite the development of antibody-drug conjugates, the fragment Fab-based drug conjugates offer some unique capabilities in terms of safety, clearance, penetration and others. Current methods for preparing Fab drug conjugates are limited by the availability and stability of Fab proteins, leaving reports on this rare. Here, we found that a single-chain scaffold of Fab enables stabilization of the paired structure and supports high-yield expression in bacteria cytoplasm. Furthermore, we conjugated anti-neoplastic agent SN38 to the C-terminus by sortase A ligation and generated a homogenous Fab conjugate with the drug-to-Fab ratio of 1. The resulting anti-HER2 Fab-SN38 conjugate demonstrated potent and antigen-dependent cell-killing ability with the aid of its special cathepsin-triggered cyclization-promoted release mechanism. In vivo, Fab-SN38 can prevent growths of HER2-positive tumors in athymic mice and be well tolerated to the treatment at 7 mg/kg per dose. Anti-tumor activity, high dose tolerance and penetration advantage observed in this study would merit Fab conjugate investigation in target chemotherapy.

Tumor microenvironment immunomodulation by nanoformulated TLR 7/8 agonist and PI3k delta inhibitor enhances therapeutic benefits of radiotherapy.

Infiltration of immunosuppressive cells into the breast tumor microenvironment (TME) is associated with suppressed effector T cell (Teff) responses, accelerated tumor growth, and poor clinical outcomes. Previous studies from our group and others identified infiltration of immunosuppressive myeloid-derived suppressor cells (MDSCs) and regulatory T cells (Tregs) as critical contributors to immune dysfunction in the orthotopic claudin-low tumor model, limiting the efficacy of adoptive cellular therapy. However, approaches to target these cells in the TME are currently lacking. To overcome this barrier, polymeric micellular nanoparticles (PMNPs) were used for the co-delivery of small molecule drugs activating Toll-like receptors 7 and 8 (TLR7/8) and inhibiting PI3K delta (PI3Kδ). The immunomodulation of the TME by TLR7/8 agonist and PI3K inhibitor led to type 1 macrophage polarization, decreased MDSC accumulation and selectively decreased tissue-resident Tregs in the TME, while enhancing the T and B cell adaptive immune responses. PMNPs significantly enhanced the anti-tumor activity of local radiation therapy (RT) in mice bearing orthotopic claudin-low tumors compared to RT alone. Taken together, these data demonstrate that RT combined with a nanoformulated immunostimulant diminished the immunosuppressive TME resulting in tumor regression. These findings set the stage for clinical studies of this approach.

Napabucasin deactivates STAT3 and promotes mitoxantrone-mediated cGAS-STING activation for hepatocellular carcinoma chemo-immunotherapy.

The immune resistance of tumor microenvironment (TME) causes immune checkpoint blockade therapy inefficient to hepatocellular carcinoma (HCC). Emerging strategies of using chemotherapy regimens to reverse the immune resistance provide the promise for promoting the efficiency of immune checkpoint inhibitors. The induction of cyclic guanosine monophosphate-adenosine monophosphate synthase (cGAS)-stimulator of interferon genes (STING) in tumor cells evokes the adaptive immunity and remodels the immunosuppressive TME. In this study, we report that mitoxantrone (MIT, a chemotherapeutic drug) activates the cGAS-STING signaling pathway of HCC cells. We provide an approach to augment the efficacy of MIT using a signal transducer and activator of transcription 3 (STAT3) inhibitor called napabucasin (NAP). We prepare an aminoethyl anisamide (AEAA)-targeted polyethylene glycol (PEG)-modified poly (lactic-co-glycolic acid) (PLGA)-based nanocarrier for co-delivery of MIT and NAP. The resultant co-nanoformulation can elicit the cGAS-STING-based immune responses to reshape the immunoresistant TME in the mice orthotopically grafted with HCC. Consequently, the resultant co-nanoformulation can promote anti-PD-1 antibody for suppressing HCC development, generating long-term survival, and inhibiting tumor recurrence. This study reveals the potential of MIT to activate the cGAS-STING signaling pathway, and confirms the feasibility of nano co-delivery for MIT and NAP on achieving HCC chemo-immunotherapy.

A versatile nanoplatform carrying cascade Pt nanozymes remodeling tumor microenvironment for amplified sonodynamic/chemo therapy of thyroid cancer.

Thyroid cancer is increasing globally, with anaplastic thyroid carcinoma (ATC) being the most aggressive type and having a poor prognosis. Current clinical treatments for thyroid cancer present numerous challenges, including invasiveness and the necessity of lifelong medication. Furthermore, a significant portion of patients with ATC experience cancer recurrence and metastasis. To overcome this dilemma, we developed a pH-responsive biomimetic nanocarrier (CLP@HP-A) through the incorporation of Chlorin e6 (Ce6) and Lenvatinib (Len) within hollow polydopamine nanoparticles (HP) that were further modified with platinum nanoparticles (Pt), enabling synergistic chemotherapy and sonodynamic therapy. The CLP@HP-A nanocarriers exhibited specific binding with galectin-3 receptors, facilitating their internalization through receptor-mediated endocytosis for targeted drug delivery. Upon exposure to ultrasound (US) irradiation, Ce6 rapidly generated reactive oxygen species (ROS) to induce significant oxidative stress and trigger apoptosis in tumor cells. Additionally, Pt not only alleviated tumor hypoxia by catalyzing the conversion of H2O2 to oxygen (O2) but also augmented intracellular ROS levels through the production of hydroxyl radicals (•OH), thereby enhancing the efficacy of sonodynamic therapy. Moreover, Len demonstrated a potent cytotoxic effect on thyroid cancer cells through the induction of apoptosis. Transcriptomics analysis findings additionally corroborated that CLP@HP-A effectively triggered cancer cell apoptosis, thereby serving as a crucial mechanism for its cytotoxic effects. In conclusion, the integration of sonodynamic/chemo combination therapy with targeted drug delivery systems offers a novel approach to the management of malignant tumors.

Controlled Release of Molecules to Enhance Cell Survival and Regeneration.

Controlled release or controlled drug delivery comprises the set of techniques and approaches to improve bioavailability through improved safety and/or efficacy using a carrier material for the molecule of interest. The predictability and tunability of these carriers make them ideal for protection, localization, and sustained presentation of a wide range of therapeutics, including growth factors implicated in cell survival and regeneration. Here we provide a method for encapsulating epidermal growth factor in a degradable polymer matrix for delivery to the cornea. Additional notes are included to demonstrate the wide-ranging capabilities of such methods for other materials, therapeutic agents, and sites of action within the eye.

Sodium salicylate as a green fluorescent probe for ultrasensitive determination of vonoprazan fumarate via fluorescence switch off strategy; greenness assessment.

A green, simple and sensitive spectrofluorometric approach for determining vonoprazan fumarate in bulk and pharmaceutical dosage form by turning off the fluorescence of sodium salicylate is developed. The addition of vonoprazan fumarate reduced linearly the fluorescence intensity of 0.4 mM sodium salicylate at λem 408 nm and at λex 330 nm. The approach was found to be linear in the 50.0-3000.0 ng/mL range. The limits of detection and quantification were 10.97 and 33.23 ng/mL, respectively. The presented method proved its suitability in determination of vonoprazan fumarate in its pure and pharmaceutical dosage form. This method employs water as the exclusive solvent and utilizes safe reagents, evaluated using the Analytical Eco Scale, Green Analytical Procedure Index (GAPI), and carbon footprint. In contrast, previous methods relied on toxic reagents and required extended heating times, resulting in higher environmental impact. The novel method not only enhances analytical efficiency but also aligns with green chemistry principles, offering a sustainable solution for routine pharmaceutical analysis.

In vivo and in vitro study on the regulatory mechanism of XiaoChaiHu decoction on PANoptosis in sepsis-induced cardiomyopathy.

ETHNOPHARMACOLOGICAL RELEVANCE: In accordance with the tenets of traditional Chinese medicine, sepsis is categorized into three distinct syndromes: heat syndrome, blood stasis syndrome, and deficiency syndrome. Xiaochaihu decoction (XCHD) has many functions, including the capacity to protect the liver, cholagogue, antipyretic, anti-inflammatory, and anti-pathogenic microorganisms. XCHD exerts the effect of clearing heat and reconciling Shaoyang. The XCHD contains many efficacious active ingredients, yet the mechanism of sepsis-induced cardiomyopathy (SIC) remains elusive. AIM OF THE STUDY: To investigate the molecular mechanisms underlying the protective effects of XCHD against SIC using an integrated approach combining network pharmacology and molecular biology techniques. MATERIALS AND METHODS: Network pharmacology methods identified the active ingredients, target proteins, and pathways affected by XCHD in the context of SIC. We conducted in vivo experiments using mice with lipopolysaccharide-induced SIC, evaluating cardiac function through echocardiography and histology. XCHD-containing serum was analyzed to determine its principal active components using ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). The effects of XCHD-containing serum on SIC were further tested in vitro in LPS-treated H9c2 cardiac cells. Protein expression levels were quantified via Western blotting and enzyme-linked immunosorbent assay (ELISA). Additionally, molecular docking was performed between the active components and ZBP1, a potential target protein. Overexpression of ZBP1 in H9c2 cells allowed for a deeper exploration of its role in modulating SIC-associated gene expression. RESULTS: UPLC-MS/MS identified 31 shared XCHD and XCHD-containing serum components. These included organic acids, terpenoids, and flavonoids, which have been identified as the active components of XCHD. Our findings revealed that XCHD alleviated LPS-induced myocardial injury, improved cardiac function, and preserved cardiomyocyte morphology in mice. In vitro studies, we demonstrated that XCHD-containing serum significantly suppressed the expression of inflammatory cytokines (IL-6, IL-1ß, and TNF-α) in LPS-induced H9c2 cells. Mechanistic investigations showed that XCHD downregulated genes associated with PANoptosis, a novel cell death pathway, suggesting its protective role in sepsis-damaged hearts. Conversely, overexpression of ZBP1 abolished the protective effects of XCHD and amplified PANoptosis-related gene expression. CONCLUSIONS: Our study provides the first evidence supporting the protective effects of XCHD against SIC, both in vitro and in vivo. The underlying mechanism involves the inhibition of ZBP1-initiated PANoptosis, offering new insights into treating SIC using XCHD.

Intravascular delivery of an MK2 inhibitory peptide to prevent restenosis after angioplasty.

Peripheral artery disease is commonly treated with balloon angioplasty, a procedure involving minimally invasive, transluminal insertion of a catheter to the site of stenosis, where a balloon is inflated to open the blockage, restoring blood flow. However, peripheral angioplasty has a high rate of restenosis, limiting long-term patency. Therefore, angioplasty is sometimes paired with delivery of cytotoxic drugs like paclitaxel to reduce neointimal tissue formation. We pursue intravascular drug delivery strategies that target the underlying cause of restenosis - intimal hyperplasia resulting from stress-induced vascular smooth muscle cell switching from the healthy contractile into a pathological synthetic phenotype. We have established MAPKAP kinase 2 (MK2) as a driver of this phenotype switch and seek to establish convective and contact transfer (coated balloon) methods for MK2 inhibitory peptide delivery to sites of angioplasty. Using a flow loop bioreactor, we showed MK2 inhibition in ex vivo arteries suppresses smooth muscle cell phenotype switching while preserving vessel contractility. A rat carotid artery balloon injury model demonstrated inhibition of intimal hyperplasia following MK2i coated balloon treatment in vivo. These studies establish both convective and drug coated balloon strategies as promising approaches for intravascular delivery of MK2 inhibitory formulations to improve efficacy of balloon angioplasty.

Lipidic drug delivery systems are responsive to the human microbiome.

In vitro and in vivo tests for therapeutic agents are typically conducted in sterile environments, but many target areas for drug delivery are home to thousands of microbial species. Here, we examine the behaviour of lipidic nanomaterials after exposure to representative strains of four bacterial species found in the gastrointestinal tract and skin. Small angle X-ray scattering measurements show that the nanostructure of monoolein cubic and inverse hexagonal phases are transformed, respectively, into inverse hexagonal and inverse micellar cubic phases upon exposure to a strain of live Staphylococcus aureus often present on skin and mucosa. Further investigation demonstrates that enzymatic hydrolysis and cell membrane lipid transfer are both likely responsible for this effect. The structural responses to S. aureus are rapid and significantly reduce the rate of drug release from monoolein-based nanomaterials. These findings are the first to demonstrate how a key species in the live human microbiome can trigger changes in the structure and drug release properties of lipidic nanomaterials. The effect appears to be strain specific, varies from patient to patient and body region to body region, and is anticipated to affect the bioapplication of monoglyceride-based formulations.

A computer-aided, heterodimer-based "triadic" carrier-free drug delivery platform to mitigate multidrug resistance in lung cancer and enhance efficiency.

Co-delivering multiple drugs or circumventing the drug efflux mechanism can significantly decrease multidrug resistance (MDR), a major cause of cancer treatment failure. In this study, we designed and fabricated a universal "three-in-one" self-delivery system for synergistic cancer therapy using a computer-aided strategy. First, we engineered two glutathione (GSH)-responsive heterodimers, ERL-SS-CPT (erlotinib [ERL] linked with camptothecin [CPT] via a disulfide bond [SS]) and CPT-SS-ERI (CPT conjugated with erianin [ERI]), which serve as both cargo and carrier material. Next, molecular dynamics simulations indicated that multiple noncovalent molecular forces, including π-π stacking, hydrogen bonds, hydrophobic interactions, and sulfur bonds, drive the self-assembly process of these heterodimers. We then explored the universality of the heterodimers and developed a "triadic" drug delivery platform comprising 40 variants. Subsequently, we conducted case studies on docetaxel (DTX)-loaded ERL-SS-CPT nanoparticles (denoted as DTX@ERL-SS-CPT NPs) and curcumin (CUR)-loaded ERL-SS-CPT NPs (identified as CUR@CPT-SS-ERI NPs) to comprehensively investigate their self-assembly mechanism, physicochemical properties, storage stability, GSH-responsive drug release, cellular uptake, apoptosis effects, biocompatibility, and cytotoxicity. Both NPs exhibited well-defined spherical structures, high drug loading rates, and excellent storage stability. DTX@ERL-SS-CPT NPs exhibited the strongest cytotoxicity in A549 cells, following the order of DTX@ERL-SS-CPT NPs > ERL-SS-CPT NPs > CPT > DTX > ERL. Conversely, DTX@ERL-SS-CPT NPs showed negligible cytotoxicity in normal human bronchial epithelium cell line (BEAS-2B), indicating good biocompatibility and safety. Similar observations were made for CUR@CPT-SS-ERI NPs regarding biocompatibility and cytotoxicity. Upon endocytosis and encountering intracellular overexpressed GSH, the disulfide-bond linker is cleaved, resulting in the release of the versatile NPs into three parts. The spherical NPs enhance water solubility, reduce the required dosage of free drugs, and increase cellular drug accumulation while suppressing P-glycoprotein (P-gp) expression, leading to apoptosis. This work provides a computer-aided universal strategy-a heterodimer-based "triadic" drug delivery platform-to enhance anticancer efficiency while reducing multidrug resistance.

Cubosome lipid nanocarriers for delivery of ultra-short antimicrobial peptides.

HYPOTHESIS: Although antimicrobial peptides (AMPs) are a promising class of new antibiotics, their inherent susceptibility to degradation requires nanocarrier-mediated delivery. While cubosome nanocarriers have been extensively studied for delivery of AMPs, we do not currently understand why cubosome encapsulation improves antimicrobial efficacy for some compounds but not others. This study therefore aims to investigate the link between the mechanism of action and permeation efficiency of the peptides, their encapsulation efficacy, and the antimicrobial activity of these systems. EXPERIMENTS: Encapsulation and delivery of Indolicidin, and its ultra-short derivative, Priscilicidin, were investigated using SAXS, cryo-TEM and circular dichroism. Molecular dynamics simulations were used to understand the loading of these peptides within cubosomes. The antimicrobial efficacy was assessed against gram-negative (E. coli) and gram-positive (MRSA) bacteria. FINDINGS: A high ionic strength solution was required to facilitate high loading of the cationic AMPs, with bilayer encapsulation driven by tryptophan and Fmoc moieties. Cubosome encapsulation did not improve the antimicrobial efficacy of the AMPs consistent with their high permeation, as explained by a recent 'diffusion to capture model'. This suggests that cubosome encapsulation may not be an effective strategy for all antimicrobial compounds, paving the way for improved selection of nanocarriers for AMPs, and other antimicrobial compounds.

Oral formulations for highly lipophilic drugs: Impact of surface decoration on the efficacy of self-emulsifying drug delivery systems.

AIM: To evaluate the impact of the surface decoration of cannabidiol (CBD) loaded self-emulsifying drug delivery systems (SEDDS) on the efficacy of the formulations to cross the various barriers faced by orally administered drugs. METHODS: Polyethylene glycol (PEG)-free polyglycerol (PG)-based SEDDS, mixed zwitterionic phosphatidyl choline (PC)/PEG-containing SEDDS and PEG-based SEDDS were compared regarding stability against lipid degrading enzymes, surface properties, permeation across porcine mucus, cellular uptake and cytocompatibility. RESULTS: SEDDS with a size of about 200 nm with narrow size distributions were developed and loaded with 20-21 % of CBD. For PG containing PEG-free SEDDS increased degradation by lipid degrading enzymes was observed compared to PEG-containing formulations. The surface hydrophobicity of placebo SEDDS increased in the order of PG-based to mixed PC/PEG-based to PEG-based SEDDS. The influence of this surface hydrophobicity was also observed on the ability of the SEDDS to cross the mucus gel layer where highest mucus permeation was achieved for most hydrophobic PEG-based SEDDS. Highest cellular internalization was observed for PEG-based Lumogen Yellow (LY) loaded SEDDS with 92 % in Caco-2 cells compared to only 30 % for mixed PC/PEG-based SEDDS and 1 % for PG-based SEDDS, leading to a 100-fold improvement in cellular uptake for SEDDS having highest surface hydrophobicity. For cytocompatibility all developed placebo SEDDS showed similar results with a cell survival of above 75 % for concentrations below 0.05 % on Caco-2 cells. CONCLUSION: Higher surface hydrophobicity of SEDDS to orally deliver lipophilic drugs as CBD seems to be a promising approach to increase the intracellular drug concentration by an enhanced permeation through the mucus layer and cellular internalization.

Recent Advances in Nanodrug Delivery Systems Production, Efficacy, Safety, and Toxicity.

In the last three decades, the development of nanoparticles or nano-formulations as drug delivery systems has emerged as a promising tool to overcome the limitations of conventional delivery, potentially to improve the stability and solubility of active molecules, promote their transport across the biological membranes, and prolong circulation times to increase efficacy of a therapy. Despite several nano-formulations having applications in drug delivery, some issues concerning their safety and toxicity are still debated. This chapter describes the recent available information regarding safety, toxicity, and efficacy of nano-formulations for drug delivery. Several key factors can influence the behavior of nanoparticles in a biological environment, and their evaluation is crucial to design non-toxic and effective nano-formulations. Among them, we have focused our attention on materials and methods for their preparation (including the innovative microfluidic technique), mechanisms of interactions with biological systems, purification of nanoparticles, manufacture impurities, and nano-stability. This chapter places emphasis on the utilization of in silico, in vitro, and in vivo models for the assessment and prediction of toxicity associated with these nano-formulations. Furthermore, the chapter includes specific examples of in vitro and in vivo studies conducted on nanoparticles, illustrating their application in this field.

Live-Cell Calcium Imaging in 3D Intestinal Organoids.

Live-cell Ca2+ imaging is an important tool to detect activation of receptors by a putative ligand/drug and complements studies on transport processes, as intracellular Ca2+ changes provide direct evidence for substrate fluxes. Organoid-based systems offer numerous advantages over other in vitro systems such as cell lines, primary cells, or tissue explants, and in particular, intestinal organoid culture has revolutionized research on functional gastrointestinal processes. Calcium imaging using the fluorescent Ca2+ indicator Fura-2-AM can be applied to 3D intestinal organoids, which show an excellent dye-loading efficiency. Here we describe live-cell Ca2+ imaging in intestinal organoids, an important technique to improve research on malabsorption syndromes, secretory diarrhea, and metabolic disorders.

Computational Toxicology Methods in Chemical Library Design and High-Throughput Screening Hit Validation.

The discovery of molecular toxicity in a clinical drug candidate can have a significant impact on both the cost and timeline of the drug discovery process. Early identification of potentially toxic compounds during screening library preparation or, alternatively, during the hit validation process is critical to ensure that valuable time and resources are not spent pursuing compounds that may possess a high propensity for human toxicity. This report focuses on the application of computational molecular filters, applied either pre- or post-screening, to identify and remove known reactive and/or potentially toxic compounds from consideration in drug discovery campaigns.