PAMAM dendrimer - cell membrane interactions

PAMAM/miR-144 nanocarrier system inhibits the migration of gastric cancer by targeting mTOR signal transduction pathway

Exogenous microRNA-144 (miR-144) is considered as a potential biological drug for gastric cancer because of its biological activity to inhibit the epithelial-mesenchymal transition (EMT). However, the specific molecular mechanisms have not been fully revealed. In addition, their vulnerability to degradation by RNA enzymes in the blood limits their bioavailability. In this paper, a polyamidoamine (PAMAM)-wrapped miR-144 (PAMAM/miR-144) is prepared as a nanocarrier system to protect miR-144 from nuclease degradation. The PAMAM/miR-144 nanocarrier system achieves the optimal antitumor activity against gastric cancer migration and reduce mTOR protein expression by transferring miR-144 into human gastric cancer HGC-27 cells. At the same time, the PAMAM/miR-144 nanocarrier system significantly decreases the EMT via targeting mTOR signal pathway in HGC-27 cells and noticeably inhibited the growth of subcutaneous gastric cancer xenografts in nude mice. PAMAM/miR-144 nanocarrier system has effectively improved the bioavailability of miR-144, thus providing a promising combination modality for anticancer therapy.

Extracellular Matrix-Inspired Dendrimer Nanogels Encapsulating Cyclophosphamide for Systemic Sclerosis Treatment

Cyclophosphamide has a certain therapeutic effect on treating systemic sclerosis (SSc), while difficulties exist in controlling severe systematic side effects and enhancing targeting capacity. Here, inspired from the natural extracellular matrix composition, we propose a cyclophosphamide-encapsulated nanogel based on dendritic polymers polyamidoamine (PAMAM) for SSc treatment. We combine bovine serum albumin and generation 5 (G5) PAMAM dendrimers with polyphenol modification to obtain nanogels featured with antioxidant and anti-inflammatory effects. The nanogels can possess excellent biocompatibility and prevent fibroblasts from oxidative stress damage and TGF-β-mediated activation. Furthermore, in the bleomycin-induced SSc mouse model, dendrimer nanogels encapsulating cyclophosphamide also exhibit the ability to attenuate fibrosis by modulating immunity, suppressing inflammation, and reducing collagen synthesis. These findings underscore the value of this dendritic polymer nanogel in the treatment of chronic SSc, indicating its broader potential for clinical applications.

Aggregation-Induced Emission Properties of Atypical Aliphatic-Chain-Linked Siloxanes-Containing Phosphonate Esters

Phosphonate compounds have been proposed as atypical chromophores, but their luminescence properties, especially in combination with flexible aliphatic chains, remain underexplored. In this study, we have synthesized a series of novel siloxane-containing phosphonate esters as organofluorophores through a catalyst-free, one-pot Kabachnik-Fields (K-F) reaction. This reaction involved acetone, cyclohexanone, or cyclopentanone, with siloxanes containing aliphatic amines and phosphonate diesters as reactants. The resulting compounds exhibit blue fluorescence. Fluorescence tests confirmed that all synthesized materials display aggregation-induced emission (AIE) phenomena, with some also exhibiting upconversion. Notably, the luminescence intensity can be modulated by altering the steric hindrance near the phosphonate ester group. Mechanistic studies indicate that the strong blue photoluminescence observed in the aggregated state results from restricted intramolecular motion (RIM) and spatial electronic delocalization. These findings demonstrate that even simple phosphonates, when combined with flexible aliphatic chains, can exhibit significant AIE luminescence properties.

Influencing inter-cellular junctions with nanomaterials

Cell-cell junctions are essential for maintaining tissue integrity and regulating a wide range of physiological processes. While the disruption of intercellular junctions may lead to pathological conditions, it also presents an opportunity for therapeutic interventions. Nanomaterials have emerged as promising tools for modulating cell-cell junctions, offering new avenues for innovative treatments. In this review, we provide a comprehensive overview of the various nanomaterials interaction with cell-cell junctions. We discussed their underlying mechanisms, heterogenous effects on cellular behavior, and the therapeutic strategies of applying nanomaterial-induced intercellular junction disruption. Additionally, we address the challenges and opportunities involved in translating these strategies into clinical practice and discuss future directions for this rapidly advancing field.

Nanocarrier-Mediated RNA Delivery Platform as a Frontier Strategy for Hepatic Disease Treatment: Challenges and Opportunities

Hepatic diseases cause serious public health problems worldwide, and there is an urgent need to develop effective therapeutic agents. In recent years, significant progress is made in RNA therapy, and RNA molecules, such as mRNAs, siRNAs, miRNAs, and RNA aptamers, are shown to provide significant advantages in the treatment of hepatic diseases. However, the drawbacks of RNAs, such as their poor biological stability, easy degradation by nucleases in vivo, low bioavailability, and low concentrations in target tissues, significantly limit the clinical application of RNA-based drugs. Therefore, exploring and developing effective nanoscale delivery platforms for RNA therapeutics are of immense value. This review focuses on the different types of hepatic diseases and RNA therapeutics, summarizing various nanoscale delivery platforms and their strengths and weaknesses. Finally, the current status and future prospects of nanoscale delivery systems for RNA therapy are discussed.

Polymer Gels Based on PAMAM Dendrimers Functionalized with Caffeic Acid for Wound-Healing Applications

The wound-healing process has usually been related to therapeutic agents with antioxidant properties. Among them, caffeic acid, a cinnamic acid derivative, stands out. However, the use of this natural product is affected by its bioavailability and half-life. Nowadays, different approaches are being taken to improve the above-mentioned characteristics, as many active surface groups are present in polyamidoamine (PAMAM) dendrimers; without the need for extra cross-linking agents, physical gels are created by interactions such as hydrogen bonds, van der Waals forces, or π-π interactions based on the modification of the surface. One of these is functionalization with dendrimers, such as the poly(amidoamine) (PAMAM) family. To evaluate the effectiveness of functionalizing caffeic acid with PAMAM dendrimers, the in vitro and in vivo wound-healing properties of gel-PAMAM G3 conjugated with caffeic acid (GPG3Ca) and its precursor, cinnamic acid (GPG3Cin), were studied. The results showed no cytotoxicity and wound-healing activity at a concentration of 20 μg/mL in HaCaT cells with the GPG3Ca. Additionally, the ability to activate molecular mediators of the healing process was evidenced. Furthermore, GPG3Ca potentiated the in vivo wound-healing process. The positive effects and lack of cytotoxicity at the used concentration of the synthesized GPG3Ca on the wound-healing process could position it as an effective agent for wound-healing treatment.

Gallic Acid-Encapsulated PAMAM Dendrimers as an Antioxidant Delivery System for Controlled Release and Reduced Cytotoxicity against ARPE-19 Cells

Poly(amidoamine) (PAMAM) dendrimers have gained significant attention in various research fields, particularly in medicinal compound delivery. Their versatility lies in their ability to conjugate with functional molecules on their surfaces and encapsulate small molecules, making them suitable for diverse applications. Gallic acid is a potent antioxidant compound that has garnered considerable interest in recent years. Our research aims to investigate if the gallic acid-encapsulated PAMAM dendrimer generations 4 (G4(OH)-Ga) and 5 (G5(OH)-Ga) could enhance radical scavenging, which could potentially slow down the progression of age-related macular degeneration (AMD). Encapsulation of gallic acid in PAMAM dendrimers is a feasible alternative to prevent its degradation and toxicity. In vitro investigation of antioxidant activity was carried out using the DPPH and ABTS radical scavenging assays, as well as the FRAP assay. The IC50 values for DPPH and ABTS assays were determined through nonlinear dose-response curves, correlating the inhibition percentage with the concentration (μg/mL) of the sample and the concentration (μM) of gallic acid within each sample. G4(OH)-Ga and G5(OH)-Ga possess significant antioxidant activities as determined by the DPPH, ABTS, and FRAP assays. Moreover, gallic acid-encapsulated PAMAM dendrimers inhibit H2O2-induced reactive oxygen species (ROS) production in the human retinal pigment epithelium ARPE-19 cells, thereby improving antioxidant characteristics and potentially retarding AMD progression caused by ROS. In an evaluation of cell viability of ARPE-19 cells using the MTT assay, G4(OH)-Ga was found to reduce cytotoxic effects on ARPE-19 cells.

Electrochemical behaviour of poly(amidoamine) dendrimers at micropipette-based liquid/liquid micro-interfaces

Dendrimers are macromolecules with well-defined three-dimensional structures, sizes and surface charges. In this work, four generations of poly(amidoamine) (PAMAM) dendrimers were investigated at the micro-interface between two immiscible electrolyte solutions (μITIES) to understand their electrochemical responses as simple models of ionised macromolecules. Cyclic voltammetry (CV) across a range of aqueous phase pH revealed that all four generations (G0-G3) presented diffusion-controlled ion-transfer from aqueous to organic phase, while the reverse transfers from organic to aqueous phase varied with both pH and the dendrimer generation. The larger dendrimers (G2 and G3) show an adsorption behaviour at pH ≤ 3.5, but show a diffusional response at pH ≥ 6. On the other hand, the smaller dendrimers (G0 and G1) always show a diffusional response and are not impacted by the pH. This indicates that more highly charged dendrimers condense at the interface. The reverse scan of CVs showed that an increased applied potential was required to remove (desorb) these polycations from the interfaces in comparison to smaller, less charged species. Diffusion coefficients (D) were estimated, showing a decrease with increasing generation. Limits of detection for these dendrimers by CV at the μITIES were 0.4, 0.2, 0.7 and 0.5 μM for G0 to G3, respectively, while differential pulse voltammetry lowered the LODs (0.07, 0.05, 0.09 and 0.08 μM, respectively). These study shows that the μITIES provides a simple way to detect and evaluate the electrochemical behaviour of ionised macromolecules, providing a simple illustration of detection mechanism with diffusion or adsorption processes.

Using Poly(amidoamine) PAMAM-βCD Dendrimer for Controlled and Prolonged Delivery of Doxorubicin as Alternative System for Cancer Treatment

Background/Objectives: Doxorubicin (Dox) is an anticancer drug used in the treatment of a wide range of solid tumors; however, Dox causes systemic toxicity and irreversible cardiotoxicity. The design of a new nanosystem that allows for the control of Dox loading and delivery results is a powerful tool to control Dox release only in cancer cells. For this reason, supramolecular self-assembly was performed between a poly(amidoamine) (PAMAM) dendrimer decorated with four β-cyclodextrin (βCD) units (PAMAM-βCD) and an adamantane-hydrazone-doxorubicin (Ad-h-Dox) prodrug. Methods: The formation of inclusion complexes (ICs) between the prodrug and all the βCD cavities present on the surface of the PAMAM-βCD dendrimer was followed by 1H-NMR titration and corroborated by 2D NOESY experiments. A full characterization of the supramolecular assembly was performed in the solid state by thermal analysis (DSC/TGA) and scanning electron microscopy (SEM) and in solution by the DOSY NMR technique in D2O. Furthermore, the Dox release profiles from the PAMAM-βCD/Ad-h-Dox assembly at different pH values was studied by comparing the efficiency against a native βCD/Ad-h-Dox IC. Additionally, in vitro cytotoxic activity assays were performed for the nanocarrier alone and the two supramolecular assemblies in different carcinogenic cell lines. Results: The PAMAM-βCD/Ad-h-Dox assembly was adequately characterized, and the cytotoxic activity results demonstrate that the nanocarrier alone and its hydrolysis product are innocuous compared to the PAMAM-βCD/Ad-h-Dox nanocarrier that showed cytotoxicity equivalent to free Dox in the tested cancer cell lines. The in vitro drug release assays for the PAMAM-βCD/Ad-h-Dox system showed an acidic pH-dependent behavior and a prolonged profile of up to more than 72 h. Conclusions: The design of PAMAM-βCD/Ad-h-Dox consists of a new controlled and prolonged Dox release system for potential use in cancer treatment.

Aptamer sgc8-Modified PAMAM Nanoparticles for Targeted siRNA Delivery to Inhibit BCL11B in T-Cell Acute Lymphoblastic Leukemia

Introduction

T-cell acute lymphoblastic leukemia (T-ALL) is a malignant hematological disease with limited targeted therapy options. Overexpression of B-cell lymphoma/leukemia 11B is frequently observed in T-ALL and contributes to leukemogenesis. Knockdown of BCL11B inhibits T-ALL cell proliferation and induces apoptosis, making it a potential therapeutic target. However, the clinical application of siRNA therapies is hindered by challenges such as poor delivery efficiency and limited clinical outcomes.

Methods

We developed a targeted delivery system for BCL11B siRNA (siBCL11B) using generation 5 polyamidoamine (G5-PAMAM) dendrimers conjugated with the sgc8 aptamer, which specifically binds to the T-ALL cell membrane protein PTK7. This nanoparticle, designated G5-sgc8-siBCL11B, was designed to selectively deliver siRNA to T-ALL cells. In vitro and in vivo experiments were conducted to evaluate its therapeutic efficacy and safety.

Results

We demonstrate that sgc8-conjugated siBCL11B nanoparticles selectively and efficiently target BCL11B-overexpressing T-ALL cells, significantly inhibiting cell viability and promoting apoptosis while exhibiting minimal impact on the viability of normal T cells. In T-ALL mouse model studies, G5-sgc8-siBCL11B and G5-siBCL11B significantly inhibited the progression of T-ALL in vivo, extending the survival of mice compared to the control (CTR), G5, and G5-sgc8 groups. Although there was no significant difference in survival between the G5-sgc8-siBCL11B and G5-siBCL11B groups, a trend towards improved survival was observed (p = 0.0993).

Conclusion

The G5-sgc8-siBCL11B nanoparticle system demonstrated efficient delivery and significant therapeutic efficacy, highlighting its potential as a promising novel approach for the treatment of T-ALL.

Effect of polyphenolic dendrimers on biological and artificial lipid membranes

The use of dendrimers as nanovectors for nucleic acids or drugs requires the understanding of their interaction with biological membranes. This study investigates the impact of 1st generation polyphenolic carbosilane dendrimers on biological and model lipid membranes using several biophysical methods. While the increase in the z-average size of DMPC/DPPG liposomes correlated with the number of caffeic acid residues included in the dendrimer structure, dendrimers that contained polyethylene glycol chains generated lower zeta potential when interacting with a liposomal membrane. The increase in the fluorescence anisotropy of DPH and TMA-DPH probes incorporated into erythrocyte membranes predicted the ability of dendrimers to affect membrane fluidity in the hydrophobic interior and hydrophilic/polar region of a lipid bilayer. The presence of caffeic acid and polyethylene glycol chains in the dendrimer structure affected the thermodynamical properties of the membrane lipid matrix.

Dual-stage Acting Dendrimeric Nanoparticle for Deepened Chemotherapeutic Drug Delivery to Tumor Cells

Purpose

We report on the design of hypoxia-induced dual-stage acting dendrimeric nanoparticles (NPs) for selective delivery of two chemotherapeutic model drugs doxorubicin (DOX) and tirapazamin (TPZ) for deepened drug delivery into hypoxic tumors in vitro.

Methods

PAMAM G5 dendrimers were crosslinked with a hypoxic azo linker, attached to a mPEG to form a detachable corona on the dendrimer surface (PAP NPs). NPs were characterized by Zeta sizer, transmission electron microscope (TEM), Fourier transforms infrared (FTIR) and drug release kinetics. The anti-cancer performance of PAPs was evaluated by numerous tests in 2D and 3D cultured MDA-MB-231 breast cancer cells.

Results

MTT assay showed a significant difference between PAP and PAMAMG5 in terms of biocompatibility, and the effect of PAP@DOX was significantly greater than free DOX in hypoxic conditions. The results of DAPI and Annexin V-FITC/PI cell staining also confirmed uniform drug penetration as validated by induction of 90% cell apoptosis in spheroids and a high level of PAP@DOX-induced ROS generation under hypoxia conditions. Mechanistically, PAP@DOX significantly reduced the expression of mTOR, and Notch1, while the expression of Bax and Caspase3 was considerably unregulated, compared to the controls. Importantly, hypoxia-responsive disintegration and hypoxia-induced activation of HAP drug were synergized to promote deep and homogenous HAP distribution in whole microtumor regions to efficiently eliminate residual tumor cells.

Conclusion

Our results indicate the safety and high therapeutic potential of PAP system for targeted drug delivery of chemotherapeutics in particular HAPs which show maximum anti-cancer activity against hypoxic solid tumors.

The Importance of Biotinylation for the Suitability of Cationic and Neutral Fourth-Generation Polyamidoamine Dendrimers as Targeted Drug Carriers in the Therapy of Glioma and Liver Cancer

In this study, we hypothesized that biotinylated and/or glycidol-flanked fourth-generation polyamidoamine (PAMAM G4) dendrimers could be a tool for efficient drug transport into glioma and liver cancer cells. For this purpose, native PAMAM (G4) dendrimers, biotinylated (G4B), glycidylated (G4gl), and biotinylated and glycidylated (G4Bgl), were synthesized, and their cytotoxicity, uptake, and accumulation in vitro and in vivo were studied in relation to the transport mediated by the sodium-dependent multivitamin transporter (SMVT). The studies showed that the human temozolomide-resistant glioma cell line (U-118 MG) and hepatocellular carcinoma cell line (HepG2) indicated a higher amount of SMVT than human HaCaT keratinocytes (HaCaTs) used as a model of normal cells. The G4gl and G4Bgl dendrimers were highly biocompatible in vitro (they did not affect proliferation and mitochondrial activity) against HaCaT and U-118 MG glioma cells and in vivo (against Caenorhabditis elegans and Wistar rats). The studied compounds penetrated efficiently into all studied cell lines, but inconsistently with the uptake pattern observed for biotin and disproportionately for the level of SMVT. G4Bgl was taken up and accumulated after 48 h to the highest degree in glioma U-118 MG cells, where it was distributed in the whole cell area, including the nuclei. It did not induce resistance symptoms in glioma cells, unlike HepG2 cells. Based on studies on Wistar rats, there are indications that it can also penetrate the blood-brain barrier and act in the central nervous system area. Therefore, it might be a promising candidate for a carrier of therapeutic agents in glioma therapy. In turn, visualization with a confocal microscope showed that biotinylated G4B penetrated efficiently into the body of C. elegans, and it may be a useful vehicle for drugs used in anthelmintic therapy.

Notch-Targeted Therapeutic in Colorectal Cancer by Notch1 Attenuation Via Tumor Microenvironment-Responsive Cascade DNA Delivery

The Notch signaling is a key molecular pathway that regulates cell fate and development. Aberrant Notch signaling can lead to carcinogenesis and progression of malignant tumors. However, current therapies targeting Notch pathway lack specificity and induce high toxicity. In this report, a tumor microenvironment-responsive and injectable hydrogel is designed to load plasmid DNA complexes as a cascade gene delivery system to achieve precise Notch-targeted gene therapy of colorectal cancer (CRC). The hydrogels are prepared through cross-linking between phenylboric acid groups containing poly(oligo(ethylene glycol)methacrylate) (POEGMA) and epigallocatechin gallate (EGCG), used to load the complexes between plasmid DNA encoding short hairpin RNAs of Notch1 (shNotch1) and fluorinated polyamidoamine (PAMAM-F) (PAMAM-F/shNotch1). In response to low pH and H2O2 in tumor microenvironment, the hydrogel can be dissociated and release the complexes for precise delivery of shNotch1 into tumor cells and inhibit Notch1 activity to suppress malignant biological behaviors of CRC. In the subcutaneous tumor model of CRC, PAMAM-F/shNotch1-loaded hydrogels can accurately attenuate Notch1 activity and significantly inhibit tumor growth without affecting Notch signal in adjacent normal tissues. Therefore, this therapeutic system can precisely inhibit Notch1 signal in CRC with high responsiveness and low toxicity, providing a promising Notch-targeted gene therapeutic for human malignancy.

Dendrimers-Novel Therapeutic Approaches for Alzheimer's Disease

Dendrimers are covalently bonded globular nanostructures that may be used in the treatment of Alzheimer's disease (AD). Nowadays, AD therapies are focused on improving cognitive functioning and not causal treatment. However, this may change with the use of dendrimers, which are being investigated as a drug-delivery system or as a drug per se. With their ability to inhibit amyloid formation and their anti-tau properties, they are a promising therapeutic option for AD patients. Studies have shown that dendrimers may inhibit amyloid formation in at least two ways: by blocking fibril growth and by breaking already existing fibrils. Neurofibrillary tangles (NFTs) are abnormal filaments built by tau proteins that can be accumulated in the cell, which leads to the loss of cytoskeletal microtubules and tubulin-associated proteins. Cationic phosphorus dendrimers, with their anti-tau properties, can induce the aggregation of tau into amorphous structures. Drug delivery to mitochondria is difficult due to poor transport across biological barriers, such as the inner mitochondrial membrane, which is highly negatively polarized. Dendrimers may be potential nanocarriers and increase mitochondria targeting. Another considered use of dendrimers in AD treatment is as a drug-delivery system, for example, carbamazepine (CBZ) or tacrine. They can also be used to transport siRNA into neuronal tissue and to carry antioxidants and anti-inflammatory drugs to act protectively on the nervous system.

Polyamidoamine Dendrimers: Brain-Targeted Drug Delivery Systems in Glioma Therapy

Glioma is the most common primary intracranial tumor, which is formed by the malignant transformation of glial cells in the brain and spinal cord. It has the characteristics of high incidence, high recurrence rate, high mortality and low cure rate. The treatments for glioma include surgical removal, chemotherapy and radiotherapy. Due to the obstruction of the biological barrier of brain tissue, it is difficult to achieve the desired therapeutic effects. To address the limitations imposed by the brain's natural barriers and enhance the treatment efficacy, researchers have effectively used brain-targeted drug delivery systems (DDSs) in glioma therapy. Polyamidoamine (PAMAM) dendrimers, as branched macromolecular architectures, represent promising candidates for studies in glioma therapy. This review focuses on PAMAM-based DDSs in the treatment of glioma, highlighting their physicochemical characteristics, structural properties as well as an overview of the toxicity and safety profiles.

Molecular mechanism of action of imidazolium carbosilane dendrimers on the outer bacterial membrane - From membrane damage to permeability to antimicrobial endolysin

The outer bacterial membrane of drug-resistant bacteria is a significant barrier to many antimicrobials. Therefore, the development of new antibacterials primarily focuses on damaging the outer bacterial membrane of Gram-negative bacteria. Among many membrane-disrupting substances, the most promising are cationic dendritic systems. However, the mode of action may vary among different strains due to variations in the lipid compositions of the membrane. Here, we investigated the interaction of two types of cationic imidazolium carbosilane dendrimers: one with a single cationic group (methyl imidazolium) and the other with the same cationic group but attached to a functional group (a pendant pyridyl moiety), capable of establishing interactions with membranes through H-bonding or ion-dipole electrostatic interactions. We used different models of the outer membrane of Gram-negative bacteria - Escherichia coli, Pseudomonas aeruginosa, and Acinetobacter baumannii. Additionally, we assessed the combined effect of the dendrimers and the antibacterial endolysin on P. aeruginosa. Our results show that the mechanism of action depends on the type of dendrimer and the lipid composition of the membrane. We also demonstrate that the alteration of membrane fluidity and permeability to endolysin by the methyl imidazolium and pyridyl imidazolium dendrimers may play a more significant role in antimicrobial activity compared to membrane damage caused by positively charged dendrimers.

A double-edged sword: The complex interplay between engineered nanoparticles and platelets

Nanoparticles (NP) play a crucial role in nanomedicine, serving as carriers for localized therapeutics to allow for precise drug delivery to specific disease sites and conditions. When injected systemically, NP can directly interact with various blood cell types, most critically with circulating platelets. Hence, the potential activation/inhibition of platelets following NP exposure must be evaluated a priori due to possible debilitating outcomes. In recent years, various studies have helped resolve the physicochemical parameters that influence platelet-NP interactions, and either emphasize nanoparticles' therapeutic role such as to augment hemostasis or to inhibit thrombus formation, or conversely map their potential undesired side effects upon injection. In the present review, we discuss some of the main effects of several key NP types including polymeric, ceramic, silica, dendrimers and metallic NPs on platelets, with a focus on the physicochemical parameters that can dictate these effects and modulate the therapeutic potential of the NP. Despite the scientific and clinical significance of understanding Platelet-NP interactions, there is a significant knowledge gap in the field and a critical need for further investigation. Moreover, improved guidelines and research methodologies need to be developed and implemented. Our outlook includes the use of biomimetic in vitro models to investigate these complex interactions under both healthy physiological and disease conditions.

Dendrimer Platforms for Targeted Doxorubicin Delivery-Physicochemical Properties in Context of Biological Responses

The unique structure of G4.0 PAMAM dendrimers allows a drug to be enclosed in internal spaces or immobilized on the surface. In the conducted research, the conditions for the formation of the active G4.0 PAMAM complex with doxorubicin hydrochloride (DOX) were optimized. The physicochemical properties of the system were monitored using dynamic light scattering (DLS), circular dichroism (CD), and fluorescence spectroscopy. The Quartz Crystal Microbalance with Dissipation Monitoring (QCM-D) method was chosen to determine the preferential conditions for the complex formation. The highest binding efficiency of the drug to the cationic dendrimer was observed under basic conditions when the DOX molecule was deprotonated. The decrease in the zeta potential of the complex confirms that DOX immobilizes through electrostatic interaction with the carrier's surface amine groups. The binding constants were determined from the fluorescence quenching of the DOX molecule in the presence of G4.0 PAMAM. The two-fold way of binding doxorubicin in the structure of dendrimers was visible in the Isothermal calorimetry (ITC) isotherm. Fluorescence spectra and release curves identified the reversible binding of DOX to the nanocarrier. Among the selected cancer cells, the most promising anticancer activity of the G4.0-DOX complex was observed in A375 malignant melanoma cells. Moreover, the preferred intracellular location of the complexes concerning the free drug was found, which is essential from a therapeutic point of view.

Electrophoresis-Based Approach for Characterizing Dendrimer-Protein Interactions: A Proof-of-Concept Study

Improving the clinical translation of nanomedicine requires better knowledge about how nanoparticles interact with biological environments. As researchers are recognizing the importance of understanding the protein corona and characterizing how nanocarriers respond in biological systems, new tools and techniques are needed to analyze nanocarrier-protein interactions, especially for smaller size (<10 nm) nanoparticles like polyamidoamine (PAMAM) dendrimers. Here, we developed a streamlined, semiquantitative approach to assess dendrimer-protein interactions using a nondenaturing electrophoresis technique combined with mass spectrometry. With this protocol, we detect fluorescently tagged dendrimers and proteins simultaneously, enabling us to analyze when dendrimers migrate with proteins. We found that PAMAM dendrimers mostly interact with complement proteins, particularly C3 and C4a, which aligns with previously published data, verifying that our approach can be used to isolate and identify dendrimer-protein interactions.

Advancements in nanomedicine: Precision delivery strategies for male pelvic malignancies - Spotlight on prostate and colorectal cancer

BACKGROUND

Pelvic malignancies consistently pose significant global health challenges, adversely affecting the well-being of the male population. It is anticipated that clinicians will continue to confront these cancers in their practice. Nanomedicine offers promising strategies that revolutionize the treatment of male pelvic malignancies by providing precise delivery methods that aim to improve the efficacy of therapeutic outcomes while minimizing side effects. Nanoparticles are designed to encapsulate therapeutic agents and selectively target cancer cells. They can also be loaded with theragnostic agents, enabling multifunctional capabilities.

OBJECTIVE

This review aims to summarize the latest nanomedicine research into clinical applications, focusing on nanotechnology-based treatment strategies for male pelvic malignancies, encompassing chemotherapy, radiotherapy, immunotherapy, and other cutting-edge therapies. The review is structured to assist physicians, particularly those with limited knowledge of biochemistry and bioengineering, in comprehending the functionalities and applications of nanomaterials.

METHODS

Multiple databases, including PubMed, the National Library of Medicine, and Embase, were utilized to locate and review recently published articles on advancements in nano-drug delivery for prostate and colorectal cancers.

CONCLUSION

Nanomedicine possesses considerable potential in improving therapeutic outcomes and reducing adverse effects for male pelvic malignancies. Through precision delivery methods, this emerging field presents innovative treatment modalities to address these challenging diseases. Nevertheless, the majority of current studies are in the preclinical phase, with a lack of sufficient evidence to fully understand the precise mechanisms of action, absence of comprehensive pharmacotoxicity profiles, and uncertainty surrounding long-term consequences.

In vitro and ex vivo protoscolicidal effect of poly(amidoamine) nanoemulsion against Echinococcus granulosus

Hydatidosis causes a serious health hazard to humans and animals leading to significant economic and veterinary and public health concern worldwide. The present study aimed to evaluate the in vitro and ex vivo protoscolicidal effects of synthesized poly(amidoamine), PAMAM, nanoemulsion. In this study, PAMAM was characterized through dynamic light scattering technique to investigate the particle size and zeta potential of nanoemulsified polymer. For the in vitro and ex vivo assays, we used eosin dye exclusion test and scanning electron microscope (SEM) to evaluate the effects of the prepared and characterized PAMAM nanoemulsion against protoscoleces from Echinococcus granulosus sensu lato G6 (GenBank: OQ443068.1) isolated from livers of naturally infected camels. Various concentrations (0.5, 1, 1.5 and 2 mg/mL) of PAMAM nanoemulsion at different exposure times (5, 10, 20 and 30 min) were tested against protoscolices. Our findings showed that PAMAM nanoemulsion had considerable concentration- and time-dependent protoscolicidal effect at both in vitro and ex vivo experiments. Regarding in vitro assay, PAMAM nanoemulsion had a potent protoscolicidal effect when compared with the control group with a highest protoscolicidal activity observed at the concentration of 2 mg/mL at all exposure times, such that 100% of protoscolices were killed after 20 min of exposure. Also, the mortality of protoscolices was 100% after 30 min of exposure to 1 and 1.5 mg/mL of PAMAM nanoemulsion, in vitro. Concerning ex vivo assay PAMAM nanoemulsion recorded the highest mortality rates at the concentration of 2 mg/mL (55, 99.4 and 100% at 10, 20, 30 min, respectively). Ultrastructure examination of examined protoscolices after 20 min of exposure to PAMAM nanoemulsion showed a complete loss of rostellar hooks, disruption of suckers with disorganization of hooks with partial or complete loss of them, and damage of protoscolices tegument with loss of their integrity in the form of holes and contraction of the soma region were observed in 1.5 and 2 mg/mL of PAMAM, in vitro and ex vivo, showing more damage in the in vitro conditions. It can be concluded that PAMAM nanoemulsion is a promising protoscolicidal agent offering a high protoscolicidal effect at a short exposure time. Further in vivo studies and preclinical animal trials are required to evaluate its efficacy and clinical applications against hydatid cysts.

siRNA incorporated in slow-release injectable hydrogel continuously silences DDIT4 and regulates nucleus pulposus cell pyroptosis through the ROS/TXNIP/NLRP3 axis to alleviate intervertebral disc degeneration

Aims

In this investigation, we administered oxidative stress to nucleus pulposus cells (NPCs), recognized DNA-damage-inducible transcript 4 (DDIT4) as a component in intervertebral disc degeneration (IVDD), and devised a hydrogel capable of conveying small interfering RNA (siRNA) to IVDD.

Methods

An in vitro model for oxidative stress-induced injury in NPCs was developed to elucidate the mechanisms underlying the upregulation of DDIT4 expression, activation of the reactive oxygen species (ROS)-thioredoxin-interacting protein (TXNIP)-NLRP3 signalling pathway, and nucleus pulposus pyroptosis. Furthermore, the mechanism of action of small interfering DDIT4 (siDDIT4) on NPCs in vitro was validated. A triplex hydrogel named siDDIT4@G5-P-HA was created by adsorbing siDDIT4 onto fifth-generation polyamidoamine (PAMAM) dendrimer using van der Waals interactions, and then coating it with hyaluronic acid (HA). In addition, we established a rat puncture IVDD model to decipher the hydrogel's mechanism in IVDD.

Results

A correlation between DDIT4 expression levels and disc degeneration was shown with human nucleus pulposus and needle-punctured rat disc specimens. We confirmed that DDIT4 was responsible for activating the ROS-TXNIP-NLRP3 axis during oxidative stress-induced pyroptosis in rat nucleus pulposus in vitro. Mitochondria were damaged during oxidative stress, and DDIT4 contributed to mitochondrial damage and ROS production. In addition, siDDIT4@G5-P-HA hydrogels showed good delivery activity of siDDIT4 to NPCs. In vitro studies illustrated the potential of the siDDIT4@G5-P-HA hydrogel for alleviating IVDD in rats.

Conclusion

DDIT4 is a key player in mediating pyroptosis and IVDD in NPCs through the ROS-TXNIP-NLRP3 axis. Additionally, siDDIT4@G5-P-HA hydrogel has been found to relieve IVDD in rats. Our research offers an innovative treatment option for IVDD.

Metallo-Glycodendrimeric Materials against Enterotoxigenic Escherichia coli

Conjugation of carbohydrates to nanomaterials has been extensively studied and recognized as an alternative in the biomedical field. Dendrimers synthesized with mannose at the end group and with entrapped zero-valent copper/silver could be a potential candidate against bacterial proliferation. This study is aimed at investigating the bactericidal activity of metal-glycodendrimers. The Cu(I)-catalyzed azide-alkyne cycloaddition (CuAAC) reaction was used to synthesize a new mannosylated dendrimer containing 12 mannopyranoside residues in the periphery. The enterotoxigenic Escherichia coli fimbriae 4 (ETEC:F4) viability, measured at 600 nm, showed the half-inhibitory concentration (IC50) of metal-free glycodendrimers (D), copper-loaded glycodendrimers (D:Cu) and silver-loaded glycodendrimers (D:Ag) closed to 4.5 × 101, 3.5 × 101 and to 1.0 × 10-2 µg/mL, respectively, and minimum inhibitory concentration (MIC) of D, D:Cu and D:Ag of 2.0, 1.5 and 1.0 × 10-4 µg/mL, respectively. The release of bacteria contents onto broth and the inhibition of ETEC:F4 biofilm formation increased with the number of metallo-glycodendrimer materials, with a special interest in silver-containing nanomaterial, which had the highest activity, suggesting that glycodendrimer-based materials interfered with bacteria-bacteria or bacteria-polystyrene interactions, with bacteria metabolism and can disrupt bacteria cell walls. Our findings identify metal-mannose-dendrimers as potent bactericidal agents and emphasize the effect of entrapped zero-valent metal against ETEC:F4.

Intracellular delivery and deep tissue penetration of nucleoside triphosphates using photocleavable covalently bound dendritic polycations

Nucleoside triphosphates (NTPs) are essential in various biological processes. Cellular or even organismal controlled delivery of NTPs would be highly desirable, yet in cellulo and in vivo applications are hampered owing to their negative charge leading to cell impermeability. NTP transporters or NTP prodrugs have been developed, but a spatial and temporal control of the release of the investigated molecules remains challenging with these strategies. Herein, we describe a general approach to enable intracellular delivery of NTPs using covalently bound dendritic polycations, which are derived from PAMAM dendrons and their guanidinium derivatives. By design, these modifications are fully removable through attachment on a photocage, ready to deliver the native NTP upon irradiation enabling spatiotemporal control over nucleotide release. We study the intracellular distribution of the compounds depending on the linker and dendron generation as well as side chain modifications. Importantly, as the polycation is bound covalently, these molecules can also penetrate deeply into the tissue of living organisms, such as zebrafish.

Penumbra-targeted CircOGDH siRNA-loaded nanoparticles alleviate neuronal apoptosis in focal brain ischaemia

BACKGROUND

Nanoparticles (NPs) are a class of substances that can be loaded with therapeutic agents delivered to specific areas. In our earlier research, we identified a neuron-derived circular RNA (circRNA), circular oxoglutarate dehydrogenase (CircOGDH), as a promising therapeutic target for acute ischaemic stroke. This study dedicated to explore a prospective preliminary strategy of CircOGDH-based NP delivered to the ischaemic penumbra region in middle cerebral artery occlusion/reperfusion (MCAO/R) mice.

METHODS

Immunofluorescence in primary cortex neurons and in vivo fluorescence imaging revealed endocytosis of Poly(lactide-co-glycolide) (PLGA) poly amidoamine(PAMAM)@CircOGDH small interfering RNA (siRNA) NPs. Western blotting analysis and CCK8 assay were performed to evaluate the apoptotic level in ischaemic neurons treated with PLGA-PAMAM@CircOGDH siRNA NPs. Quantitative reverse transcription PCR experiments, mice behaviour test, T2 MRI analysis, Nissl and TdT-mediated dUTP nick end labeling (TUNEL) co-staining were performed to evaluate the apoptosis level of ischaemic penumbra neurons in MCAO/R mice. Biosafety evaluation of NPs in MCAO/R mice was detected by blood routine examination, liver and kidney function examination and HE staining.

RESULTS

PLGA-PAMAM@CircOGDH siRNA NPs were successfully assembled. Endocytosis of PLGA-PAMAM@CircOGDH siRNA NPs in ischaemic neurons alleviated neuronal apoptotic level in vitro and in vivo. Furthermore, mice behaviour test showed that the neurological defects of MCAO/R mice were significantly alleviated after the tail injection of PLGA-PAMAM@CircOGDH siRNA NPs, and no toxic effects were observed.

CONCLUSION

In conclusion, our results suggest that PLGA-PAMAM@CircOGDH siRNA NPs can be delivered to the ischaemic penumbra region and alleviate neuron apoptosis in MCAO/R mice and in ischaemic neurons; therefore, our study provides a desirable approach for using circRNA-based NPs for the treatment of ischaemic stroke.

Breaking Iron Homeostasis: Iron Capturing Nanocomposites for Combating Bacterial Biofilm

Given the scarcity of novel antibiotics, the eradication of bacterial biofilm infections poses formidable challenges. Upon bacterial infection, the host restricts Fe ions, which are crucial for bacterial growth and maintenance. Having coevolved with the host, bacteria developed adaptive pathways like the hemin-uptake system to avoid iron deficiency. Inspired by this, we propose a novel strategy, termed iron nutritional immunity therapy (INIT), utilizing Ga-CT@P nanocomposites constructed with gallium, copper-doped tetrakis (4-carboxyphenyl) porphyrin (TCPP) metal-organic framework, and polyamine-amine polymer dots, to target bacterial iron intakes and starve them. Owing to the similarity between iron/hemin and gallium/TCPP, gallium-incorporated porphyrin potentially deceives bacteria into uptaking gallium ions and concurrently extracts iron ions from the surrounding bacteria milieu through the porphyrin ring. This strategy orchestrates a "give and take" approach for Ga3+/Fe3+ exchange. Simultaneously, polymer dots can impede bacterial iron metabolism and serve as real-time fluorescent iron-sensing probes to continuously monitor dynamic iron restriction status. INIT based on Ga-CT@P nanocomposites induced long-term iron starvation, which affected iron-sulfur cluster biogenesis and carbohydrate metabolism, ultimately facilitating biofilm eradication and tissue regeneration. Therefore, this study presents an innovative antibacterial strategy from a nutritional perspective that sheds light on refractory bacterial infection treatment and its future clinical application.

In Vivo Applications of Dendrimers: A Step toward the Future of Nanoparticle-Mediated Therapeutics

Over the last few years, the development of nanotechnology has allowed for the synthesis of many different nanostructures with controlled sizes, shapes, and chemical properties, with dendrimers being the best-characterized of them. In this review, we present a succinct view of the structure and the synthetic procedures used for dendrimer synthesis, as well as the cellular uptake mechanisms used by these nanoparticles to gain access to the cell. In addition, the manuscript reviews the reported in vivo applications of dendrimers as drug carriers for drugs used in the treatment of cancer, neurodegenerative diseases, infections, and ocular diseases. The dendrimer-based formulations that have reached different phases of clinical trials, including safety and pharmacokinetic studies, or as delivery agents for therapeutic compounds are also presented. The continuous development of nanotechnology which makes it possible to produce increasingly sophisticated and complex dendrimers indicates that this fascinating family of nanoparticles has a wide potential in the pharmaceutical industry, especially for applications in drug delivery systems, and that the number of dendrimer-based compounds entering clinical trials will markedly increase during the coming years.

Spectroelectrochemical Analysis of Ion Transfer Mechanisms of Mitoxantrone at Liquid|Liquid Interfaces: Effects of Zwitterionic Dendrimer and Phospholipid Layer

The ionic partition property and transfer mechanism of the anthraquinone antitumor agent mitoxantrone (MTX) were studied in detail at the water|1,2-dichloroethane (DCE) interface by means of surface-sensitive spectroelectrochemical techniques. The interfacial mechanism of the cationic MTX species was composed of potential-driven ion transfer and adsorption processes. The ion association between MTX and zwitterionic polyamidoamine (PAMAM) dendrimers with peripheral carboxy groups was also investigated in terms of the effects of pH and dendritic generation. The monovalent HMTX+ interacted effectively with the negatively charged dendrimers at neutral pH, while the divalent H2MTX2+ exhibited a weak association under acidic conditions. The higher stability of the dendrimer-MTX associates in the interfacial region was found for higher dendritic generations: G3.5 ≥ G2.5 > G1.5. The interfacial behavior of MTX and its dendrimer associates was further analyzed at the phospholipid-modified interface as a model biomembrane surface. The adsorption process of HMTX+ occurred mainly on the hydrophilic side of the phospholipid layer. The spectroelectrochemical results indicated that the dendrimers penetrate into the phospholipid layer and alter the transfer mechanism of HMTX+ across the interface.

Effect of cationic dendrimer on membrane mimetic systems in the form of monolayer and bilayer

Interactions between a zwitterionic phospholipid, 1, 2-dipalmitoyl-sn-glycero-3-phosphatidylcholine (DPPC) and four anionic phospholipids dihexadecyl phosphate (DHP), 1, 2-dimyristoyl-sn-glycero-3-phosphoglycerol (DMPG), 1, 2-dipalmitoyl-sn-glycero-3-phosphate (DPP) and 1, 2-dipalmitoyl-sn-glycero-3-phospho ethanol (DPPEth) in combination with an additional amount of 30 mol% cholesterol were separately investigated at air-buffer interface through surface pressure (π) - area (A) measurements. π-A isotherm derived parameters revealed maximum negative deviation from ideality for the mixtures comprising 30 mol% anionic lipids. Besides the film functionality, structural changes of the monomolecular films at different surface pressures in the absence and presence of polyamidoamine (PAMAM, generation 4), a cationic dendrimer, were visualised through Brewster angle microscopy and fluorescence microscopic studies. Fluidity/rigidity of monolayers were assessed by surface dilatational rheology studies. Effect of PAMAM on the formation of adsorbed monolayer, due to bilayer disintegration of liposomes (DPPC:anionic lipids= 7:3 M/M, and 30 mol% cholesterol) were monitored by surface pressure (π) - time (t) isotherms. Bilayer disintegration kinetics were dependent on lipid head group and chain length, besides dendrimer concentration. Such studies are considered to be an in vitro cell membrane model where the alteration of molecular orientation play important roles in understanding the nature of interaction between the dendrimer and cell membrane. Liposome-dendrimer aggregates were nontoxic to breast cancer cell line as well as in doxorubicin treated MDA-MB-468 cell line suggesting their potential as drug delivery systems.

Preclinical evaluation of modified carbon nanohorns and their complexation with insulin

The current study emphasizes the minimal toxicity observed in vitro and in vivo for carbon nanohorns (CNHs) modified with third generation polyamidoamine (PAMAM) dendrimers. Initially, we investigated the interactions between CNH-PAMAM and lipid bilayers, which were utilized as representative models of cellular membranes for the evaluation of their toxicity in vitro. We found that the majority of those interactions occur between the modified CNHs and the polar groups of phospholipids, meaning that CNH-PAMAM does not incorporate into the lipid chains, and thus, disruption of the lipid bilayer structure is avoided. This outcome is a very important observation for further evaluation of CNH-PAPAM in cell lines and in animal models. Next, we demonstrated the potential of CNH-PAMAM for complexation with insulin, as a proof of concept for its employment as a delivery platform. Importantly, our study provides comprehensive evidence of low toxicity for CNH-PAMAM both in vitro and in vivo. The assessment of cellular toxicity revealed that the modified CNHs exhibited minimal toxicity, with concentrations of 151 μg mL-1 and 349 μg mL-1, showing negligible harm to EO771 cells and mouse embryonic fibroblasts (MEFs), respectively. Moreover, the histological analysis of the mouse livers demonstrated no evidence of tissue necrosis and inflammation, or any visible signs of severe toxicity. These findings collectively indicate the safe profile of CNH-PAMAM and further contribute to the growing body of knowledge on the safe and efficient utilization of CNH-based nanomaterials in drug and protein delivery applications.

Recent advances of polymeric nanoplatforms for cancer treatment: smart delivery systems (SDS), nanotheranostics and multidrug resistance (MDR) inhibition

Nanotheranostics is a promising field that combines the benefits of diagnostic and treatment into a single nano-platform that not only administers treatment but also allows for real-time monitoring of therapeutic response, decreasing the possibility of under/over-drug dosing. Furthermore, developing smart delivery systems (SDSs) for cancer theranostics that can take advantage of various tumour microenvironment (TME) conditions (such as deformed tumour vasculature, various over-expressed receptor proteins, reduced pH, oxidative stress, and resulting elevated glutathione levels) can aid in achieving improved pharmacokinetics, higher tumour accumulation, enhanced antitumour efficacy, and/or decreased side effects and multidrug resistance (MDR) inhibition. Polymeric nanoparticles (PNPs) are being widely investigated in this regard due to their unique features such as small size, passive/active targeting possibility, better pharmaceutical kinetics and biological distribution, decreased adverse reactions of the established drugs, inherent inhibitory properties to MDR efflux pump proteins, as well as the feasibility of delivering numerous therapeutic substances in just one design. Hence in this review, we have primarily discussed PNPs based targeted and/or controlled SDSs in which we have elaborated upon different TME mediated nanotheranostic platforms (NTPs) including active/passive/magnetic targeting platforms along with pH/ROS/redox-responsive platforms. Besides, we have elucidated different imaging guided cancer therapeutic platforms based on four major cancer imaging techniques i.e., fluorescence/photo-acoustic/radionuclide/magnetic resonance imaging, Furthermore, we have deliberated some of the most recently developed PNPs based multimodal NTPs (by combining two or more imaging or therapy techniques on a single nanoplatform) in cancer theranostics. Moreover, we have provided a brief update on PNPs based NTP which are recently developed to overcome MDR for effective cancer treatment. Additionally, we have briefly discussed about the tissue biodistribution/tumour targeting efficiency of these nanoplatforms along with recent preclinical/clinical studies. Finally, we have elaborated on various limitations associated with PNPs based nanoplatforms.

Polymer-Based Nanoparticles as Drug Delivery Systems for Purines of Established Importance in Medicine

Many purine derivatives are active pharmaceutical ingredients of significant importance in the therapy of autoimmune diseases, cancers, and viral infections. In many cases, their medical use is limited due to unfavorable physicochemical and pharmacokinetic properties. These problems can be overcome by the preparation of the prodrugs of purines or by combining these compounds with nanoparticles. Herein, we aim to review the scientific progress and perspectives for polymer-based nanoparticles as drug delivery systems for purines. Polymeric nanoparticles turned out to have the potential to augment antiviral and antiproliferative effects of purine derivatives by specific binding to receptors (ASGR1-liver, macrophage mannose receptor), increase in drug retention (in eye, intestines, and vagina), and permeation (intranasal to brain delivery, PEPT1 transport of acyclovir). The most significant achievements of polymer-based nanoparticles as drug delivery systems for purines were found for tenofovir disoproxil in protection against HIV, for acyclovir against HSV, for 6-mercaptopurine in prolongation of mice ALL model life, as well as for 6-thioguanine for increased efficacy of adoptively transferred T cells. Moreover, nanocarriers were able to diminish the toxic effects of acyclovir, didanosine, cladribine, tenofovir, 6-mercaptopurine, and 6-thioguanine.

Dendrimer-conjugated isotretinoin for controlled transdermal drug delivery

BACKGROUND

In the present study, we aimed to develop a novel isotretinoin delivery model for treating skin diseases, revealing its potential advantages in drug delivery and targeted therapy. Using a self-assembly strategy, we grafted a dendrimer, based on a well-defined branched structure for nanomedical devices, with a well-defined nanoarchitecture, yielding spherical, highly homogeneous molecules with multiple surface functionalities. Accordingly, a self-assembled dendrimer-conjugated system was developed to achieve the transdermal delivery of isotretinoin (13cRA-D).

RESULTS

Herein, 13cRA-D showed remarkable controlled release, characterized by slow release in normal tissues but accelerated release in tissues with low pH, such as sites of inflammation. These release characteristics could abrogate the nonteratogenic side effects of isotretinoin and allow efficient skin permeation. Moreover, 13cRA-D exhibited high therapeutic efficacy in acne models. Based on in vitro and in vivo experimental results, 13cRA-D afforded better skin penetration than isotretinoin and allowed lesion targeting. Additionally, 13cRA-D induced minimal skin irritation.

CONCLUSION

Our findings suggest that 13cRA-D is a safe and effective isotretinoin formulation for treating patients with skin disorders.

A Potential Effect of Circadian Rhythm in the Delivery/Therapeutic Performance of Paclitaxel-Dendrimer Nanosystems

The circadian clock controls behavior and physiology. Presently, there is clear evidence of a connection between this timing system and cancer development/progression. Moreover, circadian rhythm consideration in the therapeutic action of anticancer drugs can enhance the effectiveness of cancer therapy. Nanosized drug delivery systems (DDS) have been demonstrated to be suitable engineered platforms for drug targeted/sustained release. The investigation of the chronobiology-nanotechnology relationship, i.e., timing DDS performance according to a patient's circadian rhythm, may greatly improve cancer clinical outcomes. In the present work, we synthesized nanosystems based on an octa-arginine (R8)-modified poly(amidoamine) dendrimer conjugated with the anticancer drug paclitaxel (PTX), G4-PTX-R8, and its physicochemical properties were revealed to be appropriate for in vitro delivery. The influence of the circadian rhythm on its cellular internalization efficiency and potential therapeutic effect on human cervical cancer cells (HeLa) was studied. Cell-internalized PTX and caspase activity, as a measure of induced apoptosis, were monitored for six time points. Higher levels of PTX and caspase-3/9 were detected at T8, suggesting that the internalization of G4-PTX-R8 into HeLa cells and apoptosis are time-specific/-regulated phenomena. For a deeper understanding, the clock protein Bmal1-the main regulator of rhythmic activity, was silenced by Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR) technology. Bmal1 silencing was revealed to have an impact on both PTX release and caspase activity, evidencing a potential role for circadian rhythm on drug delivery/therapeutic effect mediated by G4-PTX-R8.

Oral delivery of biomacromolecules by overcoming biological barriers in the gastrointestinal tract: an update

INTRODUCTION

Biomacromolecules have proven to be an attractive choice for treating diseases due to their properties of strong specificity, high efficiency, and low toxicity. Besides greatly improving the patient's complaint, oral delivery of macromolecules also complies with hormone physiological secretion, which has become one of the most innovative fields of research in recent years.

AREAS COVERED

Oral delivery biological barriers for biomacromolecule, transport mechanisms, and various administration strategies were discussed in this review, including absorption enhancers, targeting nanoparticles, mucoadhesion nanoparticles, mucus penetration nanoparticles, and intelligent bionic drug delivery systems.

EXPERT OPINION

The oral delivery of biomacromolecules has important clinical implications; however, these are still facing the challenges of low bioavailability due to certain barriers. Various promising technologies have been developed to overcome the barriers and improve the therapeutic effect of oral biomacromolecules. By considering safety and efficacy comprehensively, the development of intelligent nanoparticles based on the GIT environment has demonstrated some promise in overcoming these barriers; however, a more comprehensive understanding of the oral fate of oral biomacromolecules is still required.

Advances in genetic manipulation of Chlamydia trachomatis

Chlamydia trachomatis, one species of Chlamydia spp., has the greatest impact on human health and is the main cause of bacterial sexually transmitted diseases and preventable blindness among all Chamydia spp. species. The obligate intracellular parasitism and unique biphasic developmental cycle of C. trachomatis are the main barriers for the development of tools of genetic manipulation. The past decade has witnessed significant gains in genetic manipulation of C. trachomatis, including chemical mutagenesis, group II intron-based targeted gene knockout, fluorescence-reported allelic exchange mutagenesis (FRAEM), CRISPR interference (CRISPRi) and the recently developed transposon mutagenesis. In this review, we discuss the current status of genetic manipulations of C. trachomatis and highlights new challenges in the nascent field of Chlamydia genetics.

PolySMart: a general coarse-grained molecular dynamics polymerization scheme

The development of simulation methods to study the structure and dynamics of a macroscopically sized piece of polymer material is important as such methods can elucidate structure-property relationships. Several methods have been reported to construct initial structures for homo- and co-polymers; however, most of them are only useful for short linear polymers since one needs to pack and equilibrate the far-from-equilibrium initial structures, which is a tedious task for long or hyperbranched polymers and unfeasible for polymer networks. In this method article, we present PolySMart, i.e., an open-source python package, which can effectively produce fully equilibrated homo- and hetero-polymer melts and solutions with no limitation on the polymer topology and size, at a coarse-grained resolution and through a bottom-up approach. This python package is also capable of exploring the polymerization kinetics through its reactive scheme in realistic conditions so that it can model the multiple co-occurring polymerization reactions (with different reaction rates) as well as consecutive polymerizations under stoichiometric and non-stoichiometric conditions. Thus, the equilibrated polymer models are generated through correct polymerization kinetics. A benchmark and verification of the performance of the program for several realistic cases, i.e., for homo-polymers, co-polymers, and crosslinked networks, is given. We further discuss the capability of the program to contribute to the discovery and design of new polymer materials.

Stimuli‐Responsive Dendritic Supramolecular Vector for Tumor‐Specific Gene Delivery

To simplify the preparation of dendritic materials, host–guest molecular recognition and self‐assembly are utilized to form a supramolecular dendritic gene vector (DNCVP). DNCVP is constructed from an amino dendron‐conjugated naphthol, viologen containing pH‐sensitive hydrazone‐bond‐linked PEG, and CB[8] with a molar ratio of 1:1:1. The pH‐ and reducing‐sensitivity of DNCVP is verified, and the stimuli‐responsive capacity enables the vector tumor targeting gene delivery ability. Owing to the protection of surface PEG, the supramolecular engineering endows the delivery vector with low cytotoxicity and good biocompatibility that are confirmed by the MTT assay. The excellent delivery ability of genes is investigated by in vitro transfection of pEGFP, pGL3, and silencing of siGAPDH. In vivo studies demonstrate promoted tumor accumulation of genes mediated by the dual‐responsive DNCVP and the transfection efficiency at the tumor site is greatly improved benefiting from the dynamic nature of noncovalent interactions. This study reveals DNCVP is a promising supramolecular dendritic gene delivery vector, providing a sophisticated strategy for precise gene therapy.

Dendrimers: Advancements and Potential Applications in Cancer Diagnosis and Treatment-An Overview

Cancer is a leading cause of death worldwide, and the main treatment methods for this condition are surgery, chemotherapy, and radiotherapy. These treatment methods are invasive and can cause severe adverse reactions among organisms, so nanomaterials are increasingly used as structures for anticancer therapies. Dendrimers are a type of nanomaterial with unique properties, and their production can be controlled to obtain compounds with the desired characteristics. These polymeric molecules are used in cancer diagnosis and treatment through the targeted distribution of some pharmacological substances. Dendrimers have the ability to fulfill several objectives in anticancer therapy simultaneously, such as targeting tumor cells so that healthy tissue is not affected, controlling the release of anticancer agents in the tumor microenvironment, and combining anticancer strategies based on the administration of anticancer molecules to potentiate their effect through photothermal therapy or photodynamic therapy. The purpose of this review is to summarize and highlight the possible uses of dendrimers regarding the diagnosis and treatment of oncological conditions.

Recent advances in the delivery and applications of nonviral CRISPR/Cas9 gene editing

The CRISPR (clustered regularly interspaced short palindromic repeats)/Cas9 genome editing system has been a major technological breakthrough that has brought revolutionary changes to genome editing for therapeutic and diagnostic purposes and precision medicine. With the advent of the CRISPR/Cas9 system, one of the critical limiting factors has been the safe and efficient delivery of this system to cells or tissues of interest. Several approaches have been investigated to find delivery systems that can attain tissue-targeted delivery, lowering the chances of off-target editing. While viral vectors have shown promise for in vitro, in vivo and ex vivo delivery of CRISPR/Cas9, their further clinical applications have been restricted due to shortcomings including limited cargo packaging capacity, difficulties with large-scale production, immunogenicity and insertional mutagenesis. Rapid progress in nonviral delivery vectors, including the use of lipid, polymer, peptides, and inorganic nanoparticle-based delivery systems, has established nonviral delivery approaches as a viable alternative to viral vectors. This review will introduce the molecular mechanisms of the CRISPR/Cas9 gene editing system, current strategies for delivering CRISPR/Cas9-based tools, an overview of strategies for overcoming off-target genome editing, and approaches for improving genome targeting and tissue targeting. We will also highlight current developments and recent clinical trials for the delivery of CRISPR/Cas9. Finally, future directions for overcoming the limitations and adaptation of this technology for clinical trials will be discussed.

Conjugation of Short Oligopeptides to a Second-Generation Polyamidoamine Dendrimer Shows Antibacterial Activity

The growing evolution of bacterial resistance to antibiotics represents a global issue that not only impacts healthcare systems but also political and economic processes. This necessitates the development of novel antibacterial agents. Antimicrobial peptides have shown promise in this regard. Thus, in this study, a new functional polymer was synthesized by joining a short oligopeptide sequence (Phe-Lys-Phe-Leu, FKFL) to the surface of a second-generation polyamidoamine (G2 PAMAM) dendrimer as an antibacterial component. This method of synthesis proved simple and resulted in a high conjugation yield of the product FKFL-G2. To determine its antibacterial potential, FKFL-G2 was subsequently analyzed via mass spectrometry, a cytotoxicity assay, bacterial growth assay, colony-forming unit assay, membrane permeabilization assay, transmission electron microscopy, and biofilm formation assay. FKFL-G2 was found to exhibit low toxicity to noncancerous NIH3T3 cells. Additionally, FKFL-G2 had an antibacterial effect on Escherichia coli and Staphylococcus aureus strains by interacting with and disrupting the bacterial cell membrane. Based on these findings, FKFL-G2 shows promise as a potential antibacterial agent.

Recombinant protein drugs-based intra articular drug delivery systems for osteoarthritis therapy

Osteoarthritis (OA) is the most prevalent chronic degenerative joint disease. It weakens the motor function of patients and imposes a significant economic burden on society. The current medications commonly used in clinical practice do not meet the need for the treatment of OA. Recombinant protein drugs (RPDs) can treat OA by inhibiting inflammatory pathways, regulating catabolism/anabolism, and promoting cartilage repair, thereby showing promise as disease-modifying OA drugs (DMOADs). However, the rapid clearance and short half-life of them in the articular cavity limit their clinical translation. Therefore, the reliable drug delivery systems for extending drug treatment are necessary for the further development. This review introduces RPDs with therapeutic potential for OA, and summarizes their research progress on related drug delivery systems, and make proper discussion on the certain keys for optimal development of this area.

Regulating the Membrane Affinity of Multi-module Probes to Address the Trade-off between Anchoring and Internalization

Cell membrane transport is the first and crucial step for bioprobes to realize the diagnosis, imaging, and therapy in cells. However, during this transport, there is a trade-off between anchoring and internalization steps, which will seriously affect the membrane transport efficiency. In the past, because the interaction between probes and cell membrane is constant, this challenge is hard to solve. Here, we proposed a strategy to regulate the membrane affinity of multi-module probes that enabled probe to have strong affinity during cell membrane anchoring and weak affinity during internalization. Specifically, a multi-module probe defined as LK-M-NA was constructed, which consisted of three main parts, membrane-anchoring α-helix peptide (LK), anchoring regulator (M), and therapeutic module (NA). With the α-helix module, LK-M-NA was able to rapidly anchor on the cell membrane and the binding energy was -1450.90 kcal/mol. However, after pericellular cleavage by the highly active matrix metalloproteinase-2 , LK could be removed due to the breakage of M and the binding energy reduced to -869.95 kcal/mol. Thus, the internalization restriction caused by high affinity was relieved. Owing to the alterable affinity, the membrane transport efficiency of LK-M-NA increased to 14.58%, well addressing the trade-off problem.

Facially Amphiphilic Skeleton-Derived Antibacterial Cationic Dendrimers

It is urgent to develop biocompatible and high-efficiency antimicrobial agents since microbial infections have always posed serious challenges to human health. Herein, through the marriage of facially amphiphilic skeletons and cationic dendrimers, high-density positively charged dendrimers D-CA₆-N⁺ (G2) and D-CA₂-N⁺ (G1) were designed and synthesized using the "branch" of facially amphiphilic bile acids, followed by their modification with quaternary ammonium charges. Both dendrimers could self-assemble into nanostructured micelles in aqueous solution. D-CA₆-N⁺ displays potent antibacterial activity against Staphylococcus aureus and Escherichia coli, with minimum inhibitory concentrations (MICs) as low as 7.50 and 7.79 μM, respectively, and has an evidently stronger antibacterial activity than D-CA₂-N⁺. Moreover, D-CA₆-N⁺ can kill S. aureus faster than E. coli. The facial amphiphilicity of the bile acid skeleton facilitates the selective destruction of bacterial membranes and endows dendrimers with negligible hemolysis and cytotoxicity even under a high concentration of 16× MIC. In vivo studies show that D-CA₆-N⁺ is much more effective and safer than penicillin G in treating S. aureus infection and promoting wound healing, which suggests facially amphiphilic skeleton-derived cationic dendrimers can be a promising approach to effectively enhance antibacterial activity and biocompatibility of antibacterial agent, simultaneously.

Effect of Ionization Degree of Poly(amidoamine) Dendrimer and 5-Fluorouracil on the Efficiency of Complex Formation-A Theoretical and Experimental Approach

Due to their unique structure, poly(amidoamine) (PAMAM) dendrimers can bind active ingredients in two ways: inside the structure or on their surface. The location of drug molecules significantly impacts the kinetics of active substance release and the mechanism of internalization into the cell. This study focuses on the effect of the protonation degree of the G4PAMAM dendrimer and the anticancer drug 5-fluorouracil (5FU) on the efficiency of complex formation. The most favorable conditions for constructing the G4PAMAM-5FU complex are a low degree of protonation of the dendrimer molecule with the drug simultaneously present in a deprotonated form. The fluorine components in the XPS spectra confirm the formation of the stable complex. Through SAXS and DLS methods, a decrease in the dendrimer's molecular size resulting from protonation changes at alkaline conditions was demonstrated. The gradual closure of the dendrimer structure observed at high pH values makes it difficult for the 5FU molecules to migrate to the interior of the support structure, thereby promoting drug immobilization on the surface. The ¹H NMR and DOSY spectra indicate that electrostatic interactions determine the complex formation process. Through MD simulations, the localization profile and the number of 5FU molecules forming the complex were visualized on an atomic scale.