PAMAM Dendrimers: A Review of Methodologies Employed in Biopharmaceutical Classification

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.

Advances in carrier-delivered small interfering RNA based therapeutics for treatment of neurodegenerative diseases

Neurodegenerative diseases are devastating diseases that severely affect the health of people all over the world. RNA therapies have become one of the most promising critical drug treatments for neurodegenerative diseases due to their excellent gene and protein editing effects. However, the successful transport of RNA via the systemic route to the central nervous system remains one of the major obstacles in treating neurodegenerative diseases. This review will focus on therapeutic RNA that can successfully overcome the blood-brain barrier (BBB), with particular attention to small interfering RNAs (siRNAs), focusing on different types of neurodegenerative disease treatment strategies and accelerating their translation into clinical practice.

Fabrication of Luteolin Nanoemulsion by Box-Behnken Design to Enhance its Oral Absorption Via Lymphatic Transport

Intestinal lymphatic transport offers an alternative and effective way to deliver drugs, such as avoiding first-pass metabolism, enhancing oral bioavailability, and facilitating the treatment of targeted lymphoid-related diseases. However, the clinical use of luteolin (LUT) is limited by its poor water solubility and low bioavailability, and enhancing lymphatic transport by nanoemulsion may be an efficient way to enhance its oral bioavailability. The objective of this work is to prepare the luteolin nanoemulsions (LUT NEs), optimized its preparation parameters by using Box-Behnken design optimization (BBD) and evaluated it in vitro and in vivo. An Caco-2 / Raji B cell co-incubation monolayer model was established to simulate the M-cell pathway, and the differences in the transmembrane transport of LUT and NEs were compared. Cycloheximide (CHX) was utilized to establish rat chylomicron (CM) blocking model, and for investigating the influence of pharmacokinetic parameters in rats thereafter. The results showed that LUT NEs have good stability, the particle sizes were about 23.87 ± 0.57 nm. Compared with LUT suspension, The Papp of LUT NEs was enhanced for 3.5-folds, the oral bioavailability was increased by about 2.97-folds. In addition, after binding with chylomicron, the oral bioavailability of LUT NEs was decreased for about 30% (AUC 0-∞ (μg/L*h): 5.356 ± 1.144 vs 3.753 ± 0.188). These results demonstrated that NEs could enhance the oral absorption of luteolin via lymphatic transport routes.

Sequencing of Phosphopeptides Using a Sequential Charge Inversion Ion/Ion Reaction and Electron Capture Dissociation Workflow

Protein phosphorylation, a common post-translational modification (PTM), is fundamental in a plethora of biological processes, most importantly in modulating cell signaling pathways. Matrix-assisted laser desorption/ionization (MALDI) coupled to tandem mass spectrometry (MS/MS) is an attractive method for phosphopeptide characterization due to its high speed, low limit of detection, and surface sampling capabilities. However, MALDI analysis of phosphopeptides is constrained by relatively low abundances in biological samples and poor relative ionization efficiencies in positive ion mode. Additionally, MALDI tends to produce singly charged ions, generally limiting the accessible MS/MS techniques that can be used for peptide sequencing. For example, collision induced dissociation (CID) is readily amendable to the analysis of singly charged ions, but results in facile loss of phosphoric acid, precluding the localization of the PTM. Electron-based dissociation methods (e.g., electron capture dissociation, ECD) are well suited for PTM localization, but require multiply charged peptide cations to avoid neutralization during ECD. Conversely, phosphopeptides are readily ionized using MALDI in negative ion mode. If the precursor ions are first formed in negative ion mode, a gas-phase charge inversion ion/ion reaction could then be used to transform the phosphopeptide anions produced via MALDI into multiply charged cations that are well-suited for ECD. Herein we demonstrate a multistep workflow combining a charge inversion ion/ion reaction that first transforms MALDI-generated phosphopeptide monoanions into multiply charged cations, and then subjects these multiply charged phosphopeptide cations to ECD for sequence determination and phosphate bond localization.

An Overview of Nanoparticle-Based Delivery Platforms for mRNA Vaccines for Treating Cancer

With its unique properties and potential applications, nanoparticle-based delivery platforms for messenger RNA (mRNA) vaccines have gained significant attention in recent years. Nanoparticles have the advantages of enhancing immunogenicity, targeting delivery, and improving stability, providing a new solution for drug and vaccine delivery. In some clinical studies, a variety of nanoparticle delivery platforms have been gradually applied to a wide range of vaccine applications. Current research priorities are exploring various types of nanoparticles as vaccine delivery systems to enhance vaccine stability and immunogenicity. Lipid nanoparticles (LNPs) have shown promising potential in preclinical and clinical studies on the efficient delivery of antigens to immune cells. Moreover, lipid nanoparticles and other nanoparticles for nucleic acids, especially for mRNA delivery systems, have shown vast potential for vaccine development. In this review, we present various vaccine platforms with an emphasis on nanoparticles as mRNA vaccine delivery vehicles. We describe several novel nanoparticle delivery platforms for mRNA vaccines, such as lipid-, polymer-, and protein-based nanoparticles. In addition, we provide an overview of the anti-tumor immunity of nanovaccines against different tumors in cancer immunotherapy. Finally, we outline future perspectives and remaining challenges for this promising technology of nanoparticle-based delivery platforms for vaccines.

Emerging application of nanomedicine-based therapy in acute respiratory distress syndrome

Acute lung injury (ALI) and acute respiratory distress syndrome (ARDS) are serious lung injuries caused by various factors, leading to increased permeability of the alveolar-capillary barrier, reduced stability of the alveoli, inflammatory response, and hypoxemia. Despite several decades of research since ARDS was first formally described in 1967, reliable clinical treatment options are still lacking. Currently, supportive therapy and mechanical ventilation are prioritized, and there is no medication that can be completely effective in clinical treatment. In recent years, nanomedicine has developed rapidly and has exciting preclinical treatment capabilities. Using a drug delivery system based on nanobiotechnology, local drugs can be continuously released in lung tissue at therapeutic levels, reducing the frequency of administration and improving patient compliance. Furthermore, this novel drug delivery system can target specific sites and reduce systemic side effects. Currently, many nanomedicine treatment options for ARDS have demonstrated efficacy. This review briefly introduces the pathophysiology of ARDS, discusses various research progress on using nanomedicine to treat ARDS, and anticipates future developments in related fields.

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.

Nano-based drug delivery system for therapeutics: a comprehensive review

Nanomedicine and nano-delivery systems hold unlimited potential in the developing sciences, where nanoscale carriers are employed to efficiently deliver therapeutic drugs at specifically targeted sites in a controlled manner, imparting several advantages concerning improved efficacy and minimizing adverse drug reactions. These nano-delivery systems target-oriented delivery of drugs with precision at several site-specific, with mild toxicity, prolonged circulation time, high solubility, and long retention time in the biological system, which circumvent the problems associated with the conventional delivery approach. Recently, nanocarriers such as dendrimers, liposomes, nanotubes, and nanoparticles have been extensively investigated through structural characteristics, size manipulation, and selective diagnosis through disease imaging molecules, which are very effective and introduce a new paradigm shift in drugs. In this review, the use of nanomedicines in drug delivery has been demonstrated in treating various diseases with significant advances and applications in different fields. In addition, this review discusses the current challenges and future directions for research in these promising fields as well.

Strategies for Targeted Delivery via Structurally Variant Polymeric Nanocarriers

The last decade has seen a meteoric rise in studies investigating polymeric aggregates as nanocarriers. When it comes to morphology, size, functionality, and immunostability, polymeric nanocarriers (PNCs) are unparalleled. With characteristics such as large surface area to volume ratio, amphiphilic nano‐environment, non‐toxic components, chemically modifiable composition, external surface alteration potential, uniform particle size, and stimuli‐dependent self‐assembly, PNCs have emerged as strong candidates for therapeutic applications. The article reviews the latest research on different challenges and strategies for targeted drug delivery and shall serve as guide to the researchers in designing site‐specific nanocarriers for application in future. The review systematically discusses the fundamental structural variation of the nanocarriers with emphasis on the influence of chemical alterations and the resulting effects on functionality; addresses the difficulties encountered with modes of administration; target selectivity and stimulus response.

The Design and Applications of 1,8-naphthalimide-poly(amidoamine) Dendritic Platforms

Abstract:

Poly(amidoamine) (PAMAM) is easily prepared with ethylenediamine as the precursor to form a dendritic structure with a size of 1.4 -11.4 nm from generation 1 to 10. The terminal amino groups of PAMAM could be grafted active species, such as 1,8-naphthalimide (NI) or its derivatives, to integrate their photophysical properties into PAMAM as NI-PAMAM. With/without metals, the new dendritic platforms can be found for different applications, including but not limited to sensing, imaging, antibacterial, anticancer, and liquid crystal and battery matrix. By controlling the different generations of dendrimers, the precise size less than 10 nm can be realized. In this review, we a) provide an overview of the 1,8-naphthalimide-poly(amidoamine) dendritic platforms and b) prospect that functionalized dendrimers (high algebra) could act as “nanoparticles” with the precise size to bridge the gap between functional molecules and real nanoparticles.