pH-responsive cationic liposome for endosomal escape mediated drug delivery

Biocompatible FePO4 Nanoparticles: Drug Delivery, RNA Stabilization, and Functional Activity

FePO4 NPs are of special interest in food fortification and biomedical imaging because of their biocompatibility, high bioavailability, magnetic property, and superior sensory performance that do not cause adverse organoleptic effects. These characteristics are desirable in drug delivery as well. Here, we explored the FePO4 nanoparticles as a delivery vehicle for the anticancer drug, doxorubicin, with an optimum drug loading of 26.81% ± 1.0%. This loading further enforces the formation of Fe3+ doxorubicin complex resulting in the formation of FePO4-DOX nanoparticles. FePO4-DOX nanoparticles showed a good size homogeneity and concentration-dependent biocompatibility, with over 70% biocompatibility up to 80 µg/mL concentration. Importantly, cytotoxicity analysis showed that Fe3+ complexation with DOX in FePO4-DOX NPs enhanced the cytotoxicity by around 10 times than free DOX and improved the selectivity toward cancer cells. Furthermore, FePO4 NPs temperature-stabilize RNA and support mRNA translation activity showing promises for RNA stabilizing agents. The results show the biocompatibility of iron-based inorganic nanoparticles, their drug and RNA loading, stabilization, and delivery activity with potential ramifications for food fortification and drug/RNA delivery.

Increasing Transfection Efficiency of Lipoplexes by Modulating Complexation Solution for Transient Gene Expression

Transient gene expression is a suitable tool for the production of biopharmaceutical candidates in the early stage of development and provides a simple and rapid alternative to the generation of stable cell line. In this study, an efficient transient gene expression methodology using DC-Chol/DOPE cationic liposomes and pDNA in Chinese hamster ovary suspension cells was established through screening of diverse lipoplex formation conditions. We modulated properties of both the liposome formation and pDNA solution, together called complexation solutions. Protein expression and cellular cytotoxicity were evaluated following transfection over the cell cultivation period to select the optimal complexation solution. Changes in hydrodynamic size, polydispersity index, and ζ potential of the liposomes and lipoplexes were analyzed depending on the various pH ranges of the complexation solutions using dynamic light scattering. The transfer of lipoplexes to the cytosol and their conformation were traced using fluorescence analysis until the early period of transfection. As a result, up to 1785 mg/L and 191 mg/L of human Fc protein and immunoglobulin G (bevacizumab), respectively, were successfully produced using acidic liposome formation and alkaline pDNA solutions. We expect that this lipoplex formation in acidic and alkaline complexation solutions could be an effective methodology for a promising gene delivery strategy.

USE OF ARTIFICIAL CELLS AS DRUG CARRIERS

Cells are the fundamental functional units of biological systems and mimicking their size, function and complexity is a primary goal in the development of new therapeutic strategies. Recent advances in chemistry, synthetic biology and material science have enabled the development of cell membrane-based drug delivery systems (DDSs), often referred to as "artificial cells" or protocells. Artificial cells can be made by removing functions from natural systems in a top-down manner, or assembly from synthetic, organic or inorganic materials, through a bottom-up approach where simple units are integrated to form more complex structures. This review covers the latest advances in the development of artificial cells as DDSs, highlighting how their designs have been inspired by natural cells or cell membranes. Advancement of artificial cell technologies has led to a set of drug carriers with effective and controlled release of a variety of therapeutics for a range of diseases, and with increasing complexity they will have a greater impact on therapeutic designs.

Cetuximab-siRNA Conjugate Linked Through Cationized Gelatin Knocks Down KRAS G12C Mutation in NSCLC Sensitizing the Cells Toward Gefitinib

Delivery of small-interfering RNA (siRNA) has been of great interest in the past decade for effective gene silencing. To overcome synthetic and regulatory challenges posed by nanoparticle-mediated siRNA delivery, antibody–siRNA conjugate (ARC) platform is emerging as a potential siRNA delivery system suitable for clinical translation. Herein, we have developed a delivery technology based on the ARC platform for stable delivery of siRNA called as Gelatin-Antibody Delivery System (GADS). In GADS, positively charged gelatin acts as a linker between antibody–siRNA and enables the endosomal escape of siRNA for gene silencing postcellular internalization. For proof of concept, we synthesized a scalable GADS conjugate comprising of Cetuximab (CTB), cationized gelatin (cGel) and NSCLC KRAS_G12C-specific siRNA. CTB was chemically conjugated to cGel through an amide link to form the CTB–cGel complex. Thereafter, siRNA was chemically conjugated to the cGel moiety of the complex through the thioether link to form CTB–cGel–siRNA conjugate. RP-HPLC analysis was used to monitor the reaction while gel retardation assay was used to determine siRNA loading capacity. SPR analysis showed the preservation of ligand binding affinity of antibody conjugates with K_D of ∼0.3 nM. Furthermore, cellular internalization study using florescent microscopy revealed receptor-mediated endocytosis. The conjugate targeted EGFR receptor of KRAS mutant NSCLC to specifically knockdown G12C mutation. The oncogene knockdown sensitized the cells toward small molecule inhibitor—Gefitinib causing ∼70% loss in cell viability. Western blot analysis revealed significant downregulation for various RAS downstream proteins postoncogene knockdown. Comparison of the efficiency of GADS vis-à-vis positive siRNA control and CRISPR–Cas9-based knockout of KRAS Exon 2 in the NCI-H23 NSCLC cell line suggests GADS as a potential technology for clinical translation of gene therapy.

Re-engineering a Liposome with Membranes of Red Blood Cells for Drug Delivery and Diagnostic Applications

Red blood cells (RBCs) make up the overwhelming majority of cells in the vascular system, spending most of their lives wandering the vast network of vessels that permeate every tissue of our bodies. Therefore, the delivery of any class of therapeutic agent that must stay in the circulatory system may benefit from being carried by RBCs. Toward this direction, we have re-engineered a synthetic liposome with the membranes of RBCs and incorporated a magnetic resonance imaging (MRI) contrast agent gadolinium along with the chemotherapeutic drug doxorubicin (DOX) to form a biomimetic liposome (BML). The BMLs proposed herein consist of biocompatible/biodegradable synthetic phospholipids, which include 1,2-distearoyl-sn-glycero-3-phosphoglycerol, 1,2-distearoyl-sn-glycero-3-phosphoethanolamine, and gadolinium-conjugated lipids. These synthetic phospholipids have been fused with a natural RBC membrane and are loaded with DOX using the extrusion technique. BMLs were characterized for their physicochemical properties, stability, fusogenic (between synthetic and natural lipid from RBC), magnetic, drug loading, biocompatibility, and cytotoxicity properties. BMLs had a hydrodynamic diameter of 180 ± 20 nm with a negative surface charge of 29 ± 2 mV. The longitudinal relaxivity (r1) of BML is 3.71 mM-1 s-1, which is comparable to the r1 of commercial contrast agent, Magnevist. In addition, DOX-loaded BML showed a cytotoxicity pattern similar to that of free DOX. These results showed the potential of using the proposed BML system for both MRI-based diagnostic applications and drug delivery platforms.

AT, Chuang CC, Chen JP. Liposomal IR-780 as a Highly Stable Nanotheranostic Agent for Improved Photothermal/Photodynamic Therapy of Brain Tumors by Convection-Enhanced Delivery

As a hydrophobic photosensitizer, IR-780 suffers from poor water solubility and low photostability under near infrared (NIR) light, which severely limits its use during successive NIR laser-assisted photothermal/photodynamic therapy (PTT/PDT). To solve this problem, we fabricate cationic IR-780-loaded liposomes (ILs) by entrapping IR-780 within the lipid bilayer of liposomes. We demonstrate enhanced photostability of IR-780 in ILs with well-preserved photothermal response after three repeated NIR laser exposures, in contrast to the rapid decomposition of free IR-780. The cationic nature of ILs promotes fast endocytosis of liposomal IR-780 by U87MG human glioblastoma cells within 30 min. For PTT/PDT in vitro, ILs treatment plus NIR laser irradiation leads to overexpression of heat shock protein 70 and generation of intracellular reactive oxygen species by U87MG cells, resulting in enhanced cytotoxicity and higher cell apoptosis rate. Using intracranial glioma xenograft in nude mice and administration of ILs by convection enhanced delivery (CED) to overcome blood-brain barrier, liposomal IR-780 could be specifically delivered to the brain tumor, as demonstrated from fluorescence imaging. By providing a highly stable liposomal IR-780, ILs significantly improved anti-cancer efficacy in glioma treatment, as revealed from various diagnostic imaging tools and histological examination. Overall, CED of ILs plus successive laser-assisted PTT/PDT may be an alternative approach for treating brain tumor, which can retard glioma growth and prolong animal survival times from orthotopic brain tumor models.

Hollow structures as drug carriers: Recognition, response, and release

Hollow structures have demonstrated great potential in drug delivery owing to their privileged structure, such as high surface-to-volume ratio, low density, large cavities, and hierarchical pores. In this review, we provide a comprehensive overview of hollow structured materials applied in targeting recognition, smart response, and drug release, and we have addressed the possible chemical factors and reactions in these three processes. The advantages of hollow nanostructures are summarized as follows: hollow cavity contributes to large loading capacity; a tailored structure helps controllable drug release; variable compounds adapt to flexible application; surface modification facilitates smart responsive release. Especially, because the multiple physical barriers and chemical interactions can be induced by multishells, hollow multishelled structure is considered as a promising material with unique loading and releasing properties. Finally, we conclude this review with some perspectives on the future research and development of the hollow structures as drug carriers.

Nanoscopy for endosomal escape quantification

The successful cytosolic delivery of nanoparticles is hampered by their endosomal entrapment and degradation. To push forward the smart development of nanoparticles we must reliably detect and quantify their endosomal escape process. However, the current methods employed are not quantitative enough at the nanoscale to achieve this. Nanoscopy is a rapidly evolving field that has developed a diverse set of powerful techniques in the last two decades, opening the door to explore nanomedicine with an unprecedented resolution and specificity. The understanding of key steps in the drug delivery process - such as endosomal escape - would benefit greatly from the implementation of the most recent advances in microscopy. In this review, we provide the latest insights into endosomal escape of nanoparticles obtained by nanoscopy, and we discuss the features that would allow these techniques to make a great impact in the field.

Iron(iii) chelated paramagnetic polymeric nanoparticle formulation as a next-generation T1-weighted MRI contrast agent

In pursuit of safer alternatives to Gd-based MRI contrast agents due to its toxicity and organ deposition, herein, we developed a safer and efficient clinically relevant iron(iii) chelated polymeric nanoparticle as a T1-weighted MRI contrast agent.

Stimulus-responsive luminescent hydrogels: Design and applications

Luminescent hydrogels are emerging soft materials with applications in photoelectric, biomedicine, sensors and actuators, which are fabricated via covalently conjugation of luminophors to hydrogelators or physical loading of luminescent organic/inorganic materials into hydrogel matrices. Due to the intrinsic stimulus-responsiveness for hydrogels such as thermo-, pH, ionic strength, light and redox, luminescent hydrogels could respond to external physical or chemical stimuli through varying the luminescent properties such as colors, fluorescent intensity and so on, affording diverse application potential in addition to the pristine individual hydrogels or luminescent materials. Based on the rapid development of such area, here we systematically summarize and discuss the design protocols, properties as well as the applications of stimulus-responsive luminescent hydrogels. Because of the stimuli-responsiveness, biocompatibility, injectable and controllability of luminescent hydrogels, they are widely used as functional smart materials. We illustrate the applications of luminescent hydrogels. The future developments about luminescent hydrogels are also presented.

Improved oral delivery of quercetin with hyaluronic acid containing niosomes as a promising formulation

Quercetin, a substance from nature has various biological effects; while, some challenges like low solubility in water and absorption, and high first-pass metabolism hindered its clinical efficiencies. So, various strategies using novel nanocarriers have been designed to overcome these obstacles. This study aimed to fabricate the polymeric niosomes by incorporating hyaluronic acid to deliver quercetin. After preparation, quercetin entrapped niosomes were investigated in terms of size, zeta potential, quercetin entrapment, CTAB turbidimetric assay, AFM, TEM, differential scanning Calorimetry, X-Ray diffraction, DPPH antioxidant determination, and in vivo anti-inflammatory analysis. The analysis of the results exhibited that size of niosomes containing quercetin and hyaluronic acid was 231.07 ± 8.39 nm with a zeta potential of -34.00 ± 0.95 mV. Moreover, quercetin entrapment efficiency and loading were 94.67 ± 1.62% and 1.65 ± 0.37%, respectively. TEM and AFM showed that polymeric niosomes were spheres. The release data presented that the Higuchi model was the best-fitted model. DPPH antioxidant determination displayed that 80 µl of polymeric niosomes with 7.46 × 10^-8mol of quercetin had a remarkable antioxidant potency. According to the in vivo oedema evaluation, the potency of polymeric formulations was superior to the simple suspension of quercetin to control inflammation in rats by oral administration.

Biomimetic Synthesis and Evaluation of Interconnected Bimodal Mesostructured MSF@Poly(Ethyleneimine)s for Improved Drug Loading and Oral Adsorption of the Poorly Water-Soluble Drug, Ibuprofen

Purpose

The aim of this study was to improve the oral bioavailability and anti-inflammatory activity of the poorly soluble drug ibuprofen (IBU) by employing a new kind of poly(ethyleneimine)s (PEIs)-based mesocellular siliceous foam (MSF) called B-BMSF@PEI as drug carrier.

Methods

B-BMSF@PEI was biomimetically synthesized by using PEIs as templates, catalysts and scaffolds under ambient conditions, and the structural characteristics, including size, morphology, mesoscopic structure and pore properties, were estimated by TEM, SEM, FTIR and N₂ desorption/adsorption measurement. Then, IBU was incorporated into B-BMSF@PEI at the drug:carrier weight ratio of 1:1. The structural features of IBU before and after drug loading were systemically characterized. IBU and B-BMSF@PEI were then subject to in vitro drug release study and wettability analysis. Finally, in vivo pharmacokinetics and anti-inflammatory pharmacodynamics studies were carried out to evaluate the efficacy of B-BMSF@PEI on improving the oral adsorption of IBU.

Results

The results demonstrated that B-BMSF@PEI was a meso–meso porous silica material with foam appearance. It consisted of uniform spherical cells (40 nm) with interconnected pore networks. IBU can be successfully loaded into B-BMSF@PEI with high efficiency (as high as 39.53%), and crystal IBU was effectively converted to an amorphous state during this process. Benefiting from the great architectures of B-BMSF@PEI, IBU/B-BMSF@PEI performed good wetting property and significantly improved the dissolution rate in both simulated gastric fluid (SGF) and simulated intestinal fluid (SIF). Notably, IBU exhibited very satisfactory relative bioavailability (681.4%) and anti-inflammatory effects (the inhibition rates were between the ranges of 113.5% to 1504.3%).

Conclusion

B-BMSF@PEI with bimodal mesoporous system and interconnected nanopores was obtained owing to the dynamic self-assembly functions of PEIs. It had superiority in drug loading and could improve the oral adsorption of ibuprofen to a satisfactory level.

Self-Assembly of Amphiphilic Compounds as a Versatile Tool for Construction of Nanoscale Drug Carriers

This review focuses on synthetic and natural amphiphilic systems prepared from straight-chain and macrocyclic compounds capable of self-assembly with the formation of nanoscale aggregates of different morphology and their application as drug carriers. Since numerous biological species (lipid membrane, bacterial cell wall, mucous membrane, corneal epithelium, biopolymers, e.g., proteins, nucleic acids) bear negatively charged fragments, much attention is paid to cationic carriers providing high affinity for encapsulated drugs to targeted cells. First part of the review is devoted to self-assembling and functional properties of surfactant systems, with special attention focusing on cationic amphiphiles, including those bearing natural or cleavable fragments. Further, lipid formulations, especially liposomes, are discussed in terms of their fabrication and application for intracellular drug delivery. This section highlights several features of these carriers, including noncovalent modification of lipid formulations by cationic surfactants, pH-responsive properties, endosomal escape, etc. Third part of the review deals with nanocarriers based on macrocyclic compounds, with such important characteristics as mucoadhesive properties emphasized. In this section, different combinations of cyclodextrin platform conjugated with polymers is considered as drug delivery systems with synergetic effect that improves solubility, targeting and biocompatibility of formulations.

Formulation of nanoliposome-encapsulated bevacizumab (Avastin): Statistical optimization for enhanced drug encapsulation and properties evaluation

Bevacizumab (Avastin®), an anti-vascular endothelial growth factor, is one of the most effective drugs widely used to inhibit ocular angiogenesis. Nanoliposomes were recruited to improve the accessibility of bevacizumab (BVZ) during treatment. To optimize drug entrapment efficiency (DEE %), the effect of some independent variables was evaluated utilizing response surface methodology. The optimized formulation containing BVZ (NLP-BVZ) was characterized, and its safety was assessed. Employingarising retinalpigment epithelial (ARPE) cells, the permeability of the nanoliposome was analyzed. Structural stability and integrity of NLP-BVZ were also estimated with different methods. Optimal condition for the maximum DEE (39.9%) was obtained with cholesterol/DPPC (1,2-Dipalimitoyl-Sn-glycero-3-phosphocholine) (%w/w) 13.64, BVZ/DPPC (%w/w) 83.78 and 9 freeze-thaw cycles. Neutral fabricated NLP-BVZ with an average size of 141.5 ± 45.8 nm showed a smooth spherical structure and released the drug in a slow and sustained fashion. The formulation exhibited no obvious effect against human umbilical vein endothelial cells (HUVECs) and ARPEs. Additionally, the pattern of the circular dichroism (CD) and intrinsic fluorescence spectra confirmed the structural integrity of protein remained conserved after encapsulation. Taken together, the analysis indicated that the process of entrapment into nanoliposome meaningfully made the drug safer, more stable, and, therefore, appropriate for treating ocular disorders.

Tailoring Iron Oxide Nanoparticles for Efficient Cellular Internalization and Endosomal Escape

Iron oxide nanoparticles (IONs) have been widely explored for biomedical applications due to their high biocompatibility, surface-coating versatility, and superparamagnetic properties. Upon exposure to an external magnetic field, IONs can be precisely directed to a region of interest and serve as exceptional delivery vehicles and cellular markers. However, the design of nanocarriers that achieve an efficient endocytic uptake, escape lysosomal degradation, and perform precise intracellular functions is still a challenge for their application in translational medicine. This review highlights several aspects that mediate the activation of the endosomal pathways, as well as the different properties that govern endosomal escape and nuclear transfection of magnetic IONs. In particular, we review a variety of ION surface modification alternatives that have emerged for facilitating their endocytic uptake and their timely escape from endosomes, with special emphasis on how these can be manipulated for the rational design of cell-penetrating vehicles. Moreover, additional modifications for enhancing nuclear transfection are also included in the design of therapeutic vehicles that must overcome this barrier. Understanding these mechanisms opens new perspectives in the strategic development of vehicles for cell tracking, cell imaging and the targeted intracellular delivery of drugs and gene therapy sequences and vectors.

Optimization of the Preparation of Magnetic Liposomes for the Combined Use of Magnetic Hyperthermia and Photothermia in Dual Magneto-Photothermal Cancer Therapy

In this work, we aimed to develop liposomal nanocomposites containing citric-acid-coated iron oxide magnetic nanoparticles (CMNPs) for dual magneto-photothermal cancer therapy induced by alternating magnetic field (AMF) and near-infrared (NIR) lasers. Toward this end, CMNPs were encapsulated in cationic liposomes to form nano-sized magnetic liposomes (MLs) for simultaneous magnetic hyperthermia (MH) in the presence of AMF and photothermia (PT) induced by NIR laser exposure, which amplified the heating efficiency for dual-mode cancer cell killing and tumor therapy. Since the heating capability is directly related to the amount of entrapped CMNPs in MLs, while the liposome size is important to allow internalization by cancer cells, response surface methodology was utilized to optimize the preparation of MLs by simultaneously maximizing the encapsulation efficiency (EE) of CMNPs in MLs and minimizing the size of MLs. The experimental design was performed based on the central composite rotatable design. The accuracy of the model was verified from the validation experiments, providing a simple and effective method for fabricating the best MLs, with an EE of 87% and liposome size of 121 nm. The CMNPs and the optimized MLs were fully characterized from chemical and physical perspectives. In the presence of dual AMF and NIR laser treatment, a suspension of MLs demonstrated amplified heat generation from dual hyperthermia (MH)-photothermia (PT) in comparison with single MH or PT. In vitro cell culture experiments confirmed the efficient cellular uptake of the MLs from confocal laser scanning microscopy due to passive accumulation in human glioblastoma U87 cells originated from the cationic nature of MLs. The inducible thermal effects mediated by MLs after endocytosis also led to enhanced cytotoxicity and cumulative cell death of cancer cells in the presence of AMF-NIR lasers. This functional nanocomposite will be a potential candidate for bimodal MH-PT dual magneto-photothermal cancer therapy.