Molecular Delivery Systems Research Articles

Multidimensional Dynamic Control of Supramolecular Phthalocyanine Gear: A Self-Assembly System Responding to Solvent, Temperature, and Hydrostatic Pressure.

Smart supramolecular materials that respond toward various external stimuli hold great promise for various applications in molecular memories, logic gates, and drug delivery systems. In this study, the active control over the self-assembly of phathalocyanine gear was achieved by combining temperature and hydrostatic pressure stimuli with a dynamic solvent. Eventually, we found that the supramolecular gear can behave as a logic gate; "engaged" (+1) or "not" (0) state is switchable by solvent, temperature, and hydrostatic pressure. This paper describes not only new aspects for the rational design of smart stimuli-responsive supramolecular materials but also the significance of multidimensional dynamic control.

Extracellular Microvesicles Modified with Arginine-Rich Peptides for Active Macropinocytosis Induction and Delivery of Therapeutic Molecules.

Extracellular vesicles (EVs), including exosomes and microvesicles (MVs), transfer bioactive molecules from donor to recipient cells in various pathophysiological settings, thereby mediating intercellular communication. Despite their significant roles in extracellular signaling, the cellular uptake mechanisms of different EV subpopulations remain unknown. In particular, plasma membrane-derived MVs are larger vesicles (100 nm to 1 μm in diameter) and may serve as efficient molecular delivery systems due to their large capacity; however, because of size limitations, receptor-mediated endocytosis is considered an inefficient means for cellular MV uptake. This study demonstrated that macropinocytosis (lamellipodia formation and plasma membrane ruffling, causing the engulfment of large fluid volumes outside cells) can enhance cellular MV uptake. We developed experimental techniques to induce macropinocytosis-mediated MV uptake by modifying MV membranes with arginine-rich cell-penetrating peptides for the intracellular delivery of therapeutic molecules.

Precise Post‐Synthetic Modification of Heterometal‐Organic Capsules for Selectively Encapsulating Tetrahedral Anions

AbstractPost‐synthetic modification plays a crucial role in precisely adjusting the structure and functions of advanced materials. Herein, we report the self‐assembly of a tubular heterometallic Pd3Cu6L16 capsule that incorporates Pd(II) and CuL1 metalloligands. This capsule undergoes further modification with two tridentate anionic ligands (L2) to afford a bicapped Pd3Cu6L16L22 capsule with an Edshammer polyhedral structure. By employing transition metal ions, acid, and oxidation agents, the bicapped capsule can be converted into an uncapped one. This uncapped form can then revert back to the bicapped structure on the addition of Br− ions and a base. Interestingly, introducing Ag+ ions leads to the removal of one L2 ligand from the bicapped capsule, yielding a mono‐capped Pd3Cu6L16L2 structure. Furthermore, the size of the anions critically influences the precise control over the post‐synthetic modifications of the capsules. It was demonstrated that these capsules selectively encapsulate tetrahedral anions, offering a novel approach for the design of intelligent molecular delivery systems.

Precise Post-Synthetic Modification of Heterometal-Organic Capsules for Selectively Encapsulating Tetrahedral Anions.

Post-synthetic modification plays a crucial role in precisely adjusting the structure and functions of advanced materials. Herein, we report the self-assembly of a tubular heterometallic Pd3Cu6L16 capsule that incorporates Pd(II) and CuL1 metalloligands. This capsule undergoes further modification with two tridentate anionic ligands (L2) to afford a bicapped Pd3Cu6L16L22 capsule with an Edshammer polyhedral structure. By employing transition metal ions, acid, and oxidation agents, the bicapped capsule can be converted into an uncapped one. This uncapped form can then revert back to the bicapped structure on the addition of Br- ions and a base. Interestingly, introducing Ag+ ions leads to the removal of one L2 ligand from the bicapped capsule, yielding a mono-capped Pd3Cu6L16L2 structure. Furthermore, the size of the anions critically influences the precise control over the post-synthetic modifications of the capsules. It was demonstrated that these capsules selectively encapsulate tetrahedral anions, offering a novel approach for the design of intelligent molecular delivery systems.

Chlorpropamide-cyclodextrin inclusion complexes, theoretical basis of stability

A study of the stability of inclusion complexes of chlorpropamide and α, β, γ, and HP-β cyclodextrin, has been carried out using molecular dynamics simulations. The contribution of weak interactions to the stability of the complexes through DFT has been analyzed. The conventional molecular dynamics analysis suggests stable complexes for the inclusion of chlorpropamide. As expected, the complex stabilization is driven by hydrophobic interactions between cyclodextrin and chlorpropamide aromatic ring; similar mobility of chlorpropamide in the cyclodextrin cavities was observed. Molecular dynamics results indicate that intermolecular hydrogen bonds appeared between 17.70 and 22.52 % of the simulation time; consequently, the crucial complex stabilizing interactions encompass more than just hydrogen bonds, revealing a more intricate network of stabilizing forces at play. For the first time, based on quantum chemistry, a correlation between the electron density contributions to weak interactions and the glucopyranose units in each CD is presented. The most relevant stabilizing interactions are of the van der Waals type, followed by small contributions from hydrogen bonds. Non-covalent interactions are more intense in the chlorpropamide/HP-β cyclodextrin complex than in other systems. The inclusion complexes formed with β-type cyclodextrins are the most stable (due to the number and intensity of the contributions), in agreement with the molecular dynamics simulation results. In addition, MMPBSA and QM energies predict CPD/αCD as unstable and least stable complex, respectively. These results highlight the importance of β-type cyclodextrins in the formation of creating reliable inclusion complexes, which could be potentially applied to molecular encapsulation and drug delivery systems.

Circular and Circulating DNA in Inflammatory Bowel Disease: From Pathogenesis to Potential Molecular Therapies.

Inflammatory bowel diseases (IBD), including Crohn's Disease (CD) and Ulcerative Colitis (UC) are chronic multifactorial disorders which affect the gastrointestinal tract with variable extent. Despite extensive research, their etiology and exact pathogenesis are still unknown. Cell-free DNAs (cfDNAs) are defined as any DNA fragments which are free from the origin cell and able to circulate into the bloodstream with or without microvescicles. CfDNAs are now being increasingly studied in different human diseases, like cancer or inflammatory diseases. However, to date it is unclear how IBD etiology is linked to cfDNAs in plasma. Extrachromosomal circular DNA (eccDNA) are non-plasmidic, nuclear, circular and closed DNA molecules found in all eukaryotes tested. CfDNAs appear to play an important role in autoimmune diseases, inflammatory processes, and cancer; recently, interest has also grown in IBD, and their role in the pathogenesis of IBD has been suggested. We now suggest that eccDNAs also play a role in IBD. In this review, we have comprehensively collected available knowledge in literature regarding cfDNA, eccDNA, and structures involving them such as neutrophil extracellular traps and exosomes, and their role in IBD. Finally, we focused on old and novel potential molecular therapies and drug delivery systems, such as nanoparticles, for IBD treatment.

Kappa-carrageenan based hybrid hydrogel for soft tissue engineering applications.

Biological materials such as cell-derived membrane vesicles have emerged as alternative sources for molecular delivery systems, owing to multicomponent features, the inherent functionalities and signaling networks, and easy-to-carry therapeutic agents with various properties. Herein, red blood cell membrane (RBCM) vesicle-laden methacrylate kappa-carrageenan (KaMA) composite hydrogel is introduced for soft tissue engineering. Results revealed that the characteristics of hybrid hydrogels were significantly modulated by changing the RBCM vesicle content. For instance, the incorporation of 20% (v/v) RBCM significantly enhanced compressive strength from 103 ± 26 kPa to 257 ± 18 kPa and improved toughness under the cyclic loading from 1.0 ± 0.4 kJ m-3to 4.0 ± 0.5 kJ m-3after the 5thcycle. RBCM vesicles were also used for the encapsulation of curcumin (CUR) as a hydrophobic drug molecule. Results showed a controlled release of CUR over three days of immersion in PBS solution. The RBCM vesicles laden KaMA hydrogels also supportedin vitrofibroblast cell growth and proliferation. In summary, this research sheds light on KaMA/RBCM hydrogels, that could reveal fine-tuned properties and hydrophobic drug release in a controlled manner.

MRNA-Based Therapeutics in Cancer Treatment

Over the past two decades, significant technological innovations have led to messenger RNA (mRNA) becoming a promising option for developing prophylactic and therapeutic vaccines, protein replacement therapies, and genome engineering. The success of the two COVID-19 mRNA vaccines has sparked new enthusiasm for other medical applications, particularly in cancer treatment. In vitro-transcribed (IVT) mRNAs are structurally designed to resemble naturally occurring mature mRNA. Delivery of IVT mRNA via delivery platforms such as lipid nanoparticles allows host cells to produce many copies of encoded proteins, which can serve as antigens to stimulate immune responses or as additional beneficial proteins for supplements. mRNA-based cancer therapeutics include mRNA cancer vaccines, mRNA encoding cytokines, chimeric antigen receptors, tumor suppressors, and other combination therapies. To better understand the current development and research status of mRNA therapies for cancer treatment, this review focused on the molecular design, delivery systems, and clinical indications of mRNA therapies in cancer.

Endometriosis, the Silent Disease: Molecular Targets, Active Principles, and Drug Delivery Systems

AbstractIn this perspective, we provide a broad overview of pathophysiological processes involved in endometriosis, including the role of inflammation, fibrosis, angiogenesis, hormonal regulation, and genetic factors. For each of the functional changes involved with the etiology of the disease, we showcase a selection of active principles in various stages of preclinical and clinical development. Finally, we highlight the role of drug delivery for endometriosis, particularly oral vs. vaginal administration. In doing so, we wish to draw the community's attention to this debilitating disease and highlight the need for interdisciplinary approaches to endometriosis treatment development.

35 years of discussions with Prof. Maeda on the EPR effect and future directions

In May 2021, 35 years after first announcing the enhanced permeability and retention (EPR) effect, Dr. Maeda passed away. As a theoretical pillar of high molecular weight drug delivery systems (DDS) with high biocompatibility, the EPR effect has been proven worldwide in experimental mouse models. However, in clinical solid tumors, awareness of the EPR effect is insufficient, and more importantly, DDS has not become the mainstream cancer treatment. Both Dr. Maeda and I were acutely aware of this, and for 35 years, we discussed what to do about it and strived to make up for the inadequacies of the EPR effect by employing different strategies. Dr. Maeda came up with ways to use tumor vascular permeability more effectively and to apply oxidative stress to tumor cells. I proposed cancer stromal targeting (CAST) therapy using the anti-insoluble fibrin antibody conjugated with an anticancer agent in order to overcome the insufficiency of the EPR effect in clinical solid cancers, which possess abundant stromal tissue. Clinical cancers are surrounded by an abundant stroma and survive even under hypoxia and malnutrition due to this stromal barrier. Cancer cells become resistant to any external attack, including with anticancer drugs and radiation. While it goes without saying that EPR effects are important in clinical solid cancer strategies, DDSs that offer both accumulation and even distribution in solid cancers are also required.

Effect of temperature, pH, and terminal groups on structural properties of carbon nanotube-dendrimer composites: A coarse-grained molecular dynamics simulation study

Using coarse-grained (CG) molecular dynamics simulation, the structural properties of carbon nanotube-dendrimer (CNT-dendrimer) are studied at different pHs and temperatures for possible application in molecular delivery systems. The studied dendrimers are Poly[amidoamine] (PAMAM) and Poly[propylene imine] (PPI), with their terminal branches functionalized with various chemical groups such as COOH, COO−, NH2, NH3+, and OH. The obtained results indicated that due to the presence of polar or charged chemical groups at the dendrimer’s terminal branches, by variation of pH at different temperatures, the size of the cavities formed inside the dendrimer can be manipulated to develop, CNT-dendrimer delivery systems with desired cavities suitable for encapsulating various molecules with different sizes. The results also indicate that while the molecular structure of the obtained dendrimers is stable, these systems look promising and customizable for drug delivery applications.

Recent Advances in the Molecular Design and Delivery Technology of mRNA for Vaccination Against Infectious Diseases.

Vaccines can prevent many millions of illnesses against infectious diseases and save numerous lives every year. However, traditional vaccines such as inactivated viral and live attenuated vaccines cannot adapt to emerging pandemics due to their time-consuming development. With the global outbreak of the COVID-19 epidemic, the virus continues to evolve and mutate, producing mutants with enhanced transmissibility and virulence; the rapid development of vaccines against such emerging global pandemics becomes more and more critical. In recent years, mRNA vaccines have been of significant interest in combating emerging infectious diseases due to their rapid development and large-scale production advantages. However, their development still suffers from many hurdles such as their safety, cellular delivery, uptake, and response to their manufacturing, logistics, and storage. More efforts are still required to optimize the molecular designs of mRNA molecules with increased protein expression and enhanced structural stability. In addition, a variety of delivery systems are also needed to achieve effective delivery of vaccines. In this review, we highlight the advances in mRNA vaccines against various infectious diseases and discuss the molecular design principles and delivery systems of associated mRNA vaccines. The current state of the clinical application of mRNA vaccine pipelines against various infectious diseases and the challenge, safety, and protective effect of associated vaccines are also discussed.

Caspase-3: Structure, function, and biotechnological aspects.

Caspase-3, a cysteine-aspartic acid protease, has recently attracted much attention because of its incredible roles in tissue differentiation, regeneration, and neural development. This enzyme is a key zymogen in cell apoptosis and is not activated until it is cleaved by initiator caspases during apoptotic flux. Since caspase-3 has represented valuable capabilities in the field of medical research, biotechnological aspects of this enzyme, including the production of recombinant type, protein engineering, and designing delivery systems, have been considered as emerging therapeutic strategies in treating the apoptosis-related disorders. To date, several advances have been made in the therapeutic use of caspase-3 in the management of some diseases such as cancers, heart failure, and neurodegenerative disorders. In the current review, we intend to discuss the caspase-3's structure, functions, therapeutic applications, as well as its molecular cloning, protein engineering, and relevant delivery systems.

Molecular hydrogen in agriculture.

H2 gas, usually in the form of H2-saturated water, could play a useful role in improving many aspects of plant growth and productivity, including resistance to stress tolerance and improved post-harvest durability. Therefore, molecular hydrogen delivery systems should be considered as a valuable addition within agricultural practice. Agriculture and food security are both impacted by plant stresses, whether that is directly from human impact or through climate change. A continuously increasing human population and rising food consumption means that there is need to search for agriculturally useful and environment friendly strategies to ensure future food security. Molecular hydrogen (H2) research has gained momentum in plant and agricultural science owing to its multifaceted and diverse roles in plants. H2 application can mitigate against a range of stresses, including salinity, heavy metals and drought. Therefore, knowing how endogenous, or exogenously applied, H2 enhances the growth and tolerance against numerous plant stresses will enhance our understanding of how H2 may be useful for future to agriculture and horticulture. In this review, recent progress and future implication of H2 in agriculture is highlighted, focusing on how H2 impacts on plant cell function and how it can be applied for better plant performance. Although the exact molecular action of H2 in plants remains elusive, this safe and easy to apply treatment should have a future in agricultural practice.

Development and Delivery Systems of mRNA Vaccines.

Since the outbreak of SARS-CoV-2, mRNA vaccine development has undergone a tremendous drive within the pharmaceutical field. In recent years, great progress has been made into mRNA vaccine development, especially in individualized tumor vaccines. mRNA vaccines are a promising approach as the production process is simple, safety profiles are better than those of DNA vaccines, and mRNA-encoded antigens are readily expressed in cells. However, mRNA vaccines also possess some inherent limitations. While side effects such as allergy, renal failure, heart failure, and infarction remain a risk, the vaccine mRNA may also be degraded quickly after administration or cause cytokine storms. This is a substantial challenge for mRNA delivery. However, appropriate carriers can avoid degradation and enhance immune responses, effector presentation, biocompatibility and biosafety. To understand the development and research status of mRNA vaccines, this review focuses on analysis of molecular design, delivery systems and clinical trials of mRNA vaccines, thus highlighting the route for wider development and further clinical trials of mRNA vaccines.

γ-Cyclodextrin-BSA for nano-encapsulation of hydrophobic substance

Self-aggregation and the hemolytic effect limit the application of γ-cyclodextrin (γ-CD) in bioactive molecular delivery systems. In this study, γ-CD was modified by grafting onto bovine serum albumin protein (BSA), with epichlorohydrin (ECH) acting as the cross-linking agent. The effects of BSA concentration, reaction temperature, pH and time on the grafting rate were studied, and the γ-CD-BSA complex with a grafting rate of 99.5 ± 0.1% ±0.06)% was achieved. The complex was confirmed using 1H NMR and FT-IR spectra. Compared with γ-CD, the hemolytic effect and self-aggregation of γ-CD-BSA were significantly reduced, and the encapsulation efficiency of curcumin was increased by 10.8%. The results of scanning electron microscopy showed that both γ-CD and γ-CD-BSA nanoparticles were formed and the structure of the γ-CD-BSA complex was more uniform. The pH stability and salt stability of γ-CD-BSA were higher than γ-CD. The release rate of γ-CD-BSA was 15.2 ± 0.2% after 2 h at pH 1.2, and 57 ± 1% after 4 h at pH 7.2. The γ-CD-BSA nanoparticles could protect curcumin in acidic environments and release it in neutral environments. The results suggested a promising wall material for delivery of hydrophobic substances.

New Small-Molecule Glycoconjugates of Docetaxel and GalNAc for Targeted Delivery to Hepatocellular Carcinoma.

In this work, we have developed covalent and low molecular weight docetaxel delivery systems based on conjugation with N-acetyl-d-galactosamine and studied their properties related to hepatocellular carcinoma cells. The resulting glycoconjugates have an excellent affinity to the asialoglycoprotein receptor (ASGPR) in the nanomolar range of concentrations and a high cytotoxicity level comparable to docetaxel. Likewise, we observed the 21-75-fold increase in water solubility in comparison with parent docetaxel and prodrug lability to intracellular conditions with half-life values from 25.5 to 42 h. We also found that the trivalent conjugate possessed selective toxicity against hepatoma cells vs control cell lines (20-35 times). The absence of such selectivity in the case of monovalent conjugates indicates the effect of ligand valency. Specific ASGPR-mediated cellular uptake of conjugates was proved in vitro using fluorescent-labeled analogues. In addition, we showed an enhanced generation of reactive oxygen species in the HepG2 cells, which could be inhibited by the natural ligand of ASGPR. Overall, the obtained results highlight the potential of ASGPR-directed cytostatic taxane drugs for selective therapy of hepatocellular carcinoma.

Multipotent miRNA Sponge-Loaded Magnetic Nanodroplets with Ultrasound/Magnet-Assisted Delivery for Hepatocellular Carcinoma Therapy.

Gene therapy is likely to be the most promising way to tackle cancer, while defects in molecular strategies and delivery systems have led to an impasse in clinical application. Here, it is found that onco-miRNAs of the miR-515 and -449 families were upregulated in hepatocellular carcinoma (HCC), and the sponge targeting miR-515 family had a significant probability to suppress cancer cell proliferation. Then, we constructed non-toxic sponge-loaded magnetic nanodroplets containing 20% C6F14 (SLMNDs-20%) that are incorporated with fluorinated superparamagnetic iron oxide nanoparticles enhancing external magnetism-assisted targeting and enabling a direct visualization of SLMNDs-20% distribution in vivo via magnetic resonance imaging monitoring. SLMNDs-20% could be vaporized by programmable focused ultrasound (FUS) activation, achieving ∼45% in vitro sponge delivery efficiency and significantly enhancing in vivo sponge delivery without a clear apoptosis. Moreover, the sponge-1-carrying SLMNDs-20% could effectively suppress proliferation of xenograft HCC after FUS exposure because sponge-1-suppressing onco-miR-515 enhanced the expression of anti-oncogenes (P21, CD22, TIMP1, NFKB, and E-cadherin) in cancer cells. The current results indicated that ultrasonic cavitation-inducing sonoporation enhanced the intracellular delivery of sponge-1 using SLMNDs-20% after magnetic-assisted accumulation, which was a therapeutic approach to inhibit HCC progression.

Extracellular vesicles produced by human and animal Staphylococcus aureus strains share a highly conserved core proteome

Staphylococcus aureus is an important opportunistic pathogen of humans and animals. It produces extracellular vesicles (EVs) that are involved in cellular communication and enable inter-kingdom crosstalk, the delivery of virulence factors and modulation of the host immune response. The protein content of EVs determines their biological functions. Clarifying which proteins are selected, and how, is of crucial value to understanding the role of EVs in pathogenesis and the development of molecular delivery systems. Here, we postulated that S. aureus EVs share a common proteome containing components involved in cargo sorting. The EV proteomes of five S. aureus strains originating from human, bovine, and ovine hosts were characterised. The clustering of EV proteomes reflected the diversity of the producing strains. A total of 253 proteins were identified, 119 of which composed a core EV proteome with functions in bacterial survival, pathogenesis, and putatively in EV biology. We also identified features in the sequences of EV proteins and the corresponding genes that could account for their packaging into EVs. Our findings corroborate the hypothesis of a selective sorting of proteins into EVs and offer new perspectives concerning the roles of EVs in S. aureus pathogenesis in specific host niches.

Side chain effect in the modulation of \u03b1v\u03b23/\u03b15\u03b21 integrin activity via clickable isoxazoline-RGD-mimetics: development of molecular delivery systems

Construction of small molecule ligand (SML) based delivery systems has been performed starting from a polyfunctionalized isoxazoline scaffold, whose αvβ3 and α5β1 integrins’ potency has been already established. The synthesis of this novel class of ligands was obtained by conjugation of linkers to the heterocyclic core via Huisgen-click reaction, with the aim to use them as “shuttles” for selective delivery of diagnostic agents to cancer cells, exploring the effects of the side chains in the interaction with the target. Compounds 17b and 24 showed excellent potency towards α5β1 integrin acting as selective antagonist and agonist respectively. Further investigations confirmed their effects on target receptor through the analysis of fibronectin-induced ERK1/2 phosphorylation. In addition, confocal microscopy analysis allowed us to follow the fate of EGFP conjugated α5β1 integrin and 17b FITC-conjugated (compound 31) inside the cells. Moreover, the stability in water solution at different values of pH and in bovine serum confirmed the possible exploitation of these peptidomimetic molecules for pharmaceutical application.