Recent Progress of Polymeric Nanogels for Gene Delivery

Multifunctional Nanocarriers for Alzheimer's Disease: Befriending the Barriers

Neurodegenerative diseases (NDDs) have been increasing in incidence in recent years and are now widespread worldwide. Neuronal death is defined as the progressive loss of neuronal structure or function which is closely associated with NDDs and represents the intrinsic features of such disorders. Amyotrophic lateral sclerosis, frontotemporal dementia, Alzheimer's, Parkinson's, and Huntington's diseases (AD, PD, and HD, respectively) are considered neurodegenerative diseases that affect a large number of people worldwide. Despite the testing of various drugs, there is currently no available therapy that can remedy or effectively slow the progression of these diseases. Nanomedicine has the potential to revolutionize drug delivery for the management of NDDs. The use of nanoparticles (NPs) has recently been developed to improve drug delivery efficiency and is currently subjected to extensive studies. Nanoengineered particles, known as nanodrugs, can cross the blood-brain barrier while also being less invasive compared to the most treatment strategies in use. Polymeric, magnetic, carbonic, and inorganic NPs are examples of NPs that have been developed to improve drug delivery efficiency. Primary research studies using NPs to cure AD are promising, but thorough research is needed to introduce these approaches to clinical use. In the present review, we discussed the role of metal-based NPs, polymeric nanogels, nanocarrier systems such as liposomes, solid lipid NPs, polymeric NPs, exosomes, quantum dots, dendrimers, polymersomes, carbon nanotubes, and nanofibers and surfactant-based systems for the therapy of neurodegenerative diseases. In addition, we highlighted nanoformulations such as N-butyl cyanoacrylate, poly(butyl cyanoacrylate), D-penicillamine, citrate-coated peptide, magnetic iron oxide, chitosan (CS), lipoprotein, ceria, silica, metallic nanoparticles, cholinesterase inhibitors, an acetylcholinesterase inhibitors, metal chelators, anti-amyloid, protein, and peptide-loaded NPs for the treatment of AD.

Oligonucleotide based nanogels for cancer therapeutics

Oligonucleotide-based nanogels, as nascent biomaterials, possess several unique functional, structural, and physicochemical features with excellent drug-loading capacity and high potential for cancer gene therapy. Ongoing studies utilizing oligonucleotide-based nanogels hold great promise, as these cutting-edge nanoplatforms can be elegantly developed with predesigned oligonucleotide sequences and complementary strands which are self-assembled or chemically crosslinked leading to the development of nanogels with predictable shape and tunable size with the desired functional properties. Current paper provides a summary of the properties, preparation methods, and applications of oligonucleotide-based nanogels in cancer therapy. The review is focused on both conventional and modified forms of oligonucleotide-based nanogels, including targeted nanogels, smart release nanogels (responsive to stimuli such as pH, temperature, and enzymes), as well as nanogels used for gene delivery. Their application in cancer immunotherapy and vaccination, photodynamic therapy, and diagnostic applications when combined with other nanoparticles is further discussed. Despite emerging designs in the development of oligonucleotide based nanogels, this field of study is still in its infancy, and clinical translation of these versatile nano-vehicles might face challenges. Hence, extensive research must be performed on in vivo behavior of such platforms determining their biodistribution, biological fate, and acute/subacute toxicity.

Optically monitoring the microenvironment of a hydrophobic cargo in amphiphilic nanogels: influence of network composition on loading and release

Amphiphilic nanogels (ANGs) are promising carriers for hydrophobic cargos such as drugs, dyes, and catalysts. Loading content and release kinetics of these compounds are controlled by type and number of hydrophobic groups in the amphiphilic copolymer network. Thus, understanding the interactions between cargo and colloidal carrier is mandatory for a tailor-made and cargo-specific ANG design. To systematically explore the influence of the network composition on these interactions, we prepared a set of ANGs of different amphiphilicity and loaded these ANGs with varying concentrations of the solvatochromic dye Nile Red (NR). Here, NR acts as a hydrophobic model cargo to optically probe the polarity of its microenvironment. Analysis of the NR emission spectra as well as measurements of the fluorescence quantum yields and decay kinetics revealed a decrease in the polarity of the NR microenvironment with increasing hydrophobicity of the hydrophobic groups in the ANG network and dye-dye interactions at higher loading concentrations. At low NR concentrations, the hydrophobic cargo NR is encapsulated in the hydrophobic domains. Increasing NR concentrations resulted in probe molecules located in a more hydrophilic environment, i.e., at the nanodomain border, and favored dye-dye interactions and NR aggregation. These results correlate well with release experiments, indicating first NR release from more hydrophilic network locations. Overall, our findings demonstrate the importance to understand carrier-drug interactions for efficient loading and controlled release profiles in amphiphilic nanogels.

Nanogels: Smart tools to enlarge the therapeutic window of gene therapy

Gene therapy can potentially treat a great number of diseases, from cancer to rare genetic disorders. Very recently, the development and emergency approval of nucleic acid-based COVID-19 vaccines confirmed its strength and versatility. However, gene therapy encounters limitations due to the lack of suitable carriers to vectorize therapeutic genetic material inside target cells. Nanogels are highly hydrated nano-size crosslinked polymeric networks that have been used in many biomedical applications, from drug delivery to tissue engineering and diagnostics. Due to their easy production, tunability, and swelling properties they have called the attention as promising vectors for gene delivery. In this review, nanogels are discussed as vectors for nucleic acid delivery aiming to enlarge gene therapy's therapeutic window. Recent works highlighting the optimization of inherent transfection efficiency and biocompatibility are reviewed here. The importance of the monomer choice, along with the internal structure, surface decoration, and responsive features are outlined for the different transfection modalities. The possible sources of toxicological endpoints in nanogels are analyzed, and the strategies to limit them are compared. Finally, perspectives are discussed to identify the remining challenges for the nanogels before their translation to the market as transfection agents.

Impact of Protein Corona Formation on the Thermoresponsive Behavior of Acrylamide-Based Nanogels

The ability to fine-tune the volume phase transition temperature (VPTT) of thermoresponsive nanoparticles is essential to their successful application in drug delivery. The rational design of these materials is limited by our understanding of the impact that nanoparticle-protein interactions have on their thermoresponsive behavior. In this work, we demonstrate how the formation of protein corona impacts the transition temperature values of acrylamide-based nanogels and their reversibility characteristics, in the presence of lysozyme, given its relevance for the ocular and intranasal administration route. Nanogels were synthesized with N-isopropylacrylamide or N-n-propylacrylamide as backbone monomers, methylenebis(acrylamide) (2.5-20 molar %) as a cross-linker, and functionalized with negatively charged monomers 2-acrylamido-2-methylpropanesulfonic acid, N-acryloyl-l-proline, or acrylic acid; characterization showed comparable particle diameter (c.a.10 nm), but formulation-dependent thermoresponsive properties, in the range 28-54 °C. Lysozyme was shown to form a complex with the negatively charged nanogels, lowering their VPTT values; the hydrophilic nature of the charged comonomer controlled the drop in VPTT upon complex formation, while matrix rigidity only had a small, yet significant effect. The cross-linker content was found to play a major role in determining the reversibility of the temperature-dependent transition of the complexes, with only 20 molar % cross-linked-nanogels displaying a fully reversible transition. These results demonstrate the importance of evaluating protein corona formation in the development of drug delivery systems based on thermoresponsive nanoparticles.

Neural cell membrane-coated DNA nanogels as a potential target-specific drug delivery tool for the central nervous system

A major bottleneck in drug/gene delivery to enhance tissue regeneration after injuries is to achieve targeted delivery to the cells of interest. Unfortunately, we have not been able to attain effective targeted drug delivery in tissues due to the lack of efficient delivery platforms. Since specific cell-cell interactions exist to impart the unique structure and functionality of tissues and organs, we hypothesize that such specific cellular interactions may also be harnessed for drug delivery applications in the form of cell membrane coatings. Here, we employed neural cell-derived membrane coating technique on DNA nanogels to improve target specificity. The efficacy of neural cell membrane-coated DNA nanogels (NCM-nanogels) was demonstrated by using four types of cell membranes derived from the central nervous system (CNS), namely, astrocytes, microglia, cortical neurons, and oligodendrocyte progenitor cells (OPCs). A successful coating of NCMs over DNA nanogels was confirmed by dynamic light scattering, zeta potential measurements and transmission electron microscopy. Subsequently, an overall improvement in cellular uptake of NCM-nanogels over uncoated DNA nanogels (p < 0.005) was seen. Additionally, we observed a selective uptake of OPC membrane-coated DNA nanogels (NCM-O mem) by oligodendrocytes over other cell types both in vitro and in vivo. Our quantitative polymerase chain reaction (qPCR) results also showed selective and effective gene knockdown capacity of NCM-O mem for OPC transfection. The findings in this work may be beneficial for future drug delivery applications targeted at the CNS.

Nanomedicine based strategies for oligonucleotide traversion across the blood-brain barrier

Neurological disorders are considered the most prominent cause of disability worldwide. The major hurdle in the management of neurological disorders is the existence of the blood-brain barrier (BBB), which hinders the entry of several therapeutic moieties. In recent years, oligonucleotides have gained tremendous attention for their target specificity, diminished dose and adverse effects, thereby halting disease progression. However, enzymatic degradation, rapid clearance, limited circulation and availability at the bio-active site, etc., limit its clinical translation. Nanomedicine has opened up a breadth of opportunities in the delivery of oligonucleotides across the BBB. This review addresses the pitfalls associated with oligonucleotide delivery in traversing the BBB via nanotherapeutics for the management of brain disorders. Regulatory perspectives pertaining to hastening the clinical translation of oligonucleotide-loaded nanocarriers for brain delivery have been highlighted.

MicroRNA: role in macrophage polarization and the pathogenesis of the liver fibrosis

Macrophages, as central components of innate immunity, feature significant heterogeneity. Numerus studies have revealed the pivotal roles of macrophages in the pathogenesis of liver fibrosis induced by various factors. Hepatic macrophages function to trigger inflammation in response to injury. They induce liver fibrosis by activating hepatic stellate cells (HSCs), and then inflammation and fibrosis are alleviated by the degradation of the extracellular matrix and release of anti-inflammatory cytokines. MicroRNAs (miRNAs), a class of small non-coding endogenous RNA molecules that regulate gene expression through translation repression or mRNA degradation, have distinct roles in modulating macrophage activation, polarization, tissue infiltration, and inflammation regression. Considering the complex etiology and pathogenesis of liver diseases, the role and mechanism of miRNAs and macrophages in liver fibrosis need to be further clarified. We first summarized the origin, phenotypes and functions of hepatic macrophages, then clarified the role of miRNAs in the polarization of macrophages. Finally, we comprehensively discussed the role of miRNAs and macrophages in the pathogenesis of liver fibrotic disease. Understanding the mechanism of hepatic macrophage heterogeneity in various types of liver fibrosis and the role of miRNAs on macrophage polarization provides a useful reference for further research on miRNA-mediated macrophage polarization in liver fibrosis, and also contributes to the development of new therapies targeting miRNA and macrophage subsets for liver fibrosis.

Polysaccharide-based hydrogels for drug delivery and wound management: a review

INTRODUCTION

Polysaccharide-based hydrogels (PBHs) offer several advantages over their synthetic counterparts. Their natural origin contributes to their nontoxicity, high biocompatibility, and in vivo biodegradability. Their properties can be tuned finely to obtain hydrogels with desired mechanical, structural, and chemical properties.

AREAS COVERED

Such versatile characteristics have potentiated the use of PBHs for the delivery of drugs, vaccines, protein and peptide therapeutics, genes, cells, probiotics, bacteriophages, and other therapeutic agents. Recent advances in hydrogel-based formulations such as nanogels, microgels, microneedles, hydrogel beads, nanocarrier-loaded hydrogels, and complexation hydrogels have enabled the precise delivery of a wide range of therapeutics. This review aims to give a holistic overview of hydrogels in the delivery of a variety of therapeutics through different routes.

EXPERT OPINION

PBHs have been used to enable the oral delivery of vaccines and other biologicals, thereby allowing self-administration of life-saving vaccines during public health emergencies. There is a lack of commercialized wound dressings for the treatment of chronic wounds. PBH-based wound dressings, especially those based on chitosan and loaded with actives and growth factors, have the potential to help in the long-term treatment of such wounds. Recent developments in the 3D printing of hydrogels can enable the quick and large-scale production of drug-loaded hydrogels.

Gold-Nanoparticle Hybrid Nanostructures for Multimodal Cancer Therapy

With the urgent need for bio-nanomaterials to improve the currently available cancer treatments, gold nanoparticle (GNP) hybrid nanostructures are rapidly rising as promising multimodal candidates for cancer therapy. Gold nanoparticles (GNPs) have been hybridized with several nanocarriers, including liposomes and polymers, to achieve chemotherapy, photothermal therapy, radiotherapy, and imaging using a single composite. The GNP nanohybrids used for targeted chemotherapy can be designed to respond to external stimuli such as heat or internal stimuli such as intratumoral pH. Despite their promise for multimodal cancer therapy, there are currently no reviews summarizing the current status of GNP nanohybrid use for cancer theragnostics. Therefore, this review fulfills this gap in the literature by providing a critical analysis of the data available on the use of GNP nanohybrids for cancer treatment with a specific focus on synergistic approaches (i.e., triggered drug release, photothermal therapy, and radiotherapy). It also highlights some of the challenges that hinder the clinical translation of GNP hybrid nanostructures from bench to bedside. Future studies that could expedite the clinical progress of GNPs, as well as the future possibility of improving GNP nanohybrids for cancer theragnostics, are also summarized.

Poly(N-isopropylacrylamide)-Based Hydrogels for Biomedical Applications: A Review of the State-of-the-Art

A prominent research topic in contemporary advanced functional materials science is the production of smart materials based on polymers that may independently adjust their physical and/or chemical characteristics when subjected to external stimuli. Smart hydrogels based on poly(N-isopropylacrylamide) (PNIPAM) demonstrate distinct thermoresponsive features close to a lower critical solution temperature (LCST) that enhance their capability in various biomedical applications such as drug delivery, tissue engineering, and wound dressings. Nevertheless, they have intrinsic shortcomings such as poor mechanical properties, limited loading capacity of actives, and poor biodegradability. Formulation of PNIPAM with diverse functional constituents to develop hydrogel composites is an efficient scheme to overcome these defects, which can significantly help for practicable application. This review reports on the latest developments in functional PNIPAM-based smart hydrogels for various biomedical applications. The first section describes the properties of PNIPAM-based hydrogels, followed by potential applications in diverse fields. Ultimately, this review summarizes the challenges and opportunities in this emerging area of research and development concerning this fascinating polymer-based system deep-rooted in chemistry and material science.

Complexation of DNA with Thermoresponsive Charged Microgels: Role of Swelling State and Electrostatics

Micro- and nanogels are being increasingly used to encapsulate bioactive compounds. Their soft structure allows large loading capacity while their stimuli responsiveness makes them extremely versatile. In this work, the complexation of DNA with thermoresponsive microgels is presented. To this end, PEGylated charged microgels based on poly-N-isopropylacrylamide have been synthesized, allowing one to explore the electrostatics of the complexation. Cationic microgels complexate spontaneously by electrostatic attraction to oppositely charged DNA as demonstrated by electrophoretic mobility of the complexes. Then, Langmuir monolayers reveal an increased interaction of DNA with swollen microgels (20 °C). Anionic microgels require the presence of multivalent cations (Ca²⁺) to promote the complexation, overcoming the electrostatic repulsion with negatively charged DNA. Then again, Langmuir monolayers evidence their complexation at the surface. However, the presence of Ca²⁺ seems to induce profound changes in the interaction and surface conformation of anionic microgels. These alterations are further explored by measuring adsorbed films with the pendant drop technique. Conformational changes induced by Ca²⁺ on the structure of the microgel can ultimately affect the complexation with DNA and should be considered in the design. The combination of microstructural and surface properties for microgels offers a new perspective into complexation of DNA with soft particles with biomedical applications.

Load phycocyanin to achieve in vivo imaging of casein-porous starch microgels induced by ultra-high-pressure homogenization

Traditional bioactive substances are often limited in practical application due to their poor stability and low solubility. Therefore, it is imperative to develop biocompatible high loading microgel carriers. In this study, a novel type of casein-porous starch microgel was prepared under ultra-high-pressure homogenization, by using porous starch with the honeycomb three-dimensional network porous structure. Molecular interaction force analysis and thermodynamic analysis showed that electrostatic interaction played a major role in the formation of microgels. Circular dichroism and Fourier transform infrared spectroscopy showed that homogenization and pH were the main factors, which affected the formation and structural stability of microgels. Compared with casein-glutinous rice starch microgels, the encapsulation efficiency and loading capacity of phycocyanin in casein-porous starch microgels were increased by 77.27% and 135.10%, respectively. Thus, casein-porous starch microgels could not only achieve a sustained release effect, but also effectively transport phycocyanin to the gastrointestinal tract of zebrafish, while achieving good fluorescence imaging in vivo. Ultimately, the prepared casein-porous starch microgels could enrich the nanocarriers material, and contribute to the research of safe and effective fluorescent imaging materials.

Supramolecular Surface Functionalization of Iron Oxide Nanoparticles with α-Cyclodextrin-Based Cationic Star Polymer for Magnetically-Enhanced Gene Delivery

Supramolecular polymers formed through host-guest complexation have inspired many interesting developments of functional materials for biological and biomedical applications. Here, we report a novel design of a non-viral gene delivery system composed of a cationic star polymer forming supramolecular complexes with the surface oleyl groups of superparamagnetic iron oxide nanoparticles (SPIONs), for magnetically enhanced delivery of DNA into mammalian cells. The cationic star polymer was synthesized by grafting multiple oligoethylenimine (OEI) chains onto an α-cyclodextrin (α-CD) core. The SPIONs were synthesized from iron(III) acetylacetonate and stabilized by hydrophobic oleic acid and oleylamine in hexane, which were characterized in terms of their size, structure, morphology, and magnetic properties. The synthesized magnetic particles were found to be superparamagnetic, making them a suitable ferrofluid for biological applications. In order to change the hydrophobic surface of the SPIONs to a hydrophilic surface with functionalities for plasmid DNA (pDNA) binding and gene delivery, a non-traditional but simple supramolecular surface modification process was used. The α-CD-OEI cationic star polymer was dissolved in water and then mixed with the SPIONs stabilized in hexane. The SPIONs were "pulled" into the water phase through the formation of supramolecular host-guest inclusion complexes between the α-CD unit and the oleyl surface of the SPIONs, while the surface of the SPIONs was changed to OEI cationic polymers. The α-CD-OEI-SPION complex could effectively bind and condense pDNA to form α-CD-OEI-SPION/pDNA polyplex nanoparticles at the size of ca. 200 nm suitable for delivery of genes into cells through endocytosis. The cytotoxicity of the α-CD-OEI-SPION complex was also found to be lower than high-molecular-weight polyethylenimine, which was widely studied previously as a standard non-viral gene vector. When gene transfection was carried out in the presence of an external magnetic field, the α-CD-OEI-SPION/pDNA polyplex nanoparticles greatly increased the gene transfection efficiency by nearly tenfold. Therefore, the study has demonstrated a facile two-in-one method to make the SPIONs water-soluble as well as functionalized for enhanced magnetofection.

Nanocarriers for Skin Applications: Where Do We Stand?

Skin penetration of active molecules for treatment of diverse diseases is a major field of research owing to the advantages associated with the skin like easy accessibility, reduced systemic‐derived side effects, and increased therapeutic efficacy. Despite these advantages, dermal drug delivery is generally challenging due to the low skin permeability of therapeutics. Although various methods have been developed to improve skin penetration and permeation of therapeutics, they are usually aggressive and could lead to irreversible damage to the stratum corneum. Nanosized carrier systems represent an alternative approach for current technologies, with minimal damage to the natural barrier function of skin. In this Review, the use of nanoparticles to deliver drug molecules, genetic material, and vaccines into the skin is discussed. In addition, nanotoxicology studies and the recent clinical development of nanoparticles are highlighted to shed light on their potential to undergo market translation.

Comprehensive review on ultrasound-responsive theranostic nanomaterials: mechanisms, structures and medical applications

The field of theranostics has been rapidly growing in recent years and nanotechnology has played a major role in this growth. Nanomaterials can be constructed to respond to a variety of different stimuli which can be internal (enzyme activity, redox potential, pH changes, temperature changes) or external (light, heat, magnetic fields, ultrasound). Theranostic nanomaterials can respond by producing an imaging signal and/or a therapeutic effect, which frequently involves cell death. Since ultrasound (US) is already well established as a clinical imaging modality, it is attractive to combine it with rationally designed nanoparticles for theranostics. The mechanisms of US interactions include cavitation microbubbles (MBs), acoustic droplet vaporization, acoustic radiation force, localized thermal effects, reactive oxygen species generation, sonoluminescence, and sonoporation. These effects can result in the release of encapsulated drugs or genes at the site of interest as well as cell death and considerable image enhancement. The present review discusses US-responsive theranostic nanomaterials under the following categories: MBs, micelles, liposomes (conventional and echogenic), niosomes, nanoemulsions, polymeric nanoparticles, chitosan nanocapsules, dendrimers, hydrogels, nanogels, gold nanoparticles, titania nanostructures, carbon nanostructures, mesoporous silica nanoparticles, fuel-free nano/micromotors.

MiR-130a-3p Alleviates Liver Fibrosis by Suppressing HSCs Activation and Skewing Macrophage to Ly6Clo Phenotype

Emerging evidences have highlighted the crucial role of microRNAs (miRNAs) in the liver cirrhosis, but the relationship between miR-130a-3p and liver cirrhosis is not entirely clear. As we all know, schistosomiasis, as one of the zoonoses, can lead to liver cirrhosis when it advances. In this study, we investigated the biological functions of miR-130a-3p on the liver fibrosis of schistosomiasis in vivo and in vitro. The mice infected with Schistosoma japonicum (S. japonicum) were treated with lentivirus vector (LV)-miR-130a-3p by hydrodynamic injection through the tail vein. Our findings showed significantly decreased expression of miR-130a-3p both in the serum of patients with cirrhosis and in the liver of mice infected with S. japonicum. The results showed that LV-miR-130a-3p could effectively enter into the liver and alleviate liver granulomatous inflammation and collagen deposition. Simultaneously, LV-miR-130a-3p-promoted macrophages presented the Ly6Clo phenotype, concomitant with the decreased expression of the tissue inhibitor of metalloproteinases (TIMP) 1, and increased the expression of matrix metalloproteinase (MMP) 2, which contributed to the dissolution of collagen. Furthermore, overexpression of miR-130a-3p not only inhibited the activation and proliferation of hepatic stellate cells (HSCs) but also induced the apoptosis of HSCs. In addition, we also confirmed that miR-130a-3p enables to bind with mitogen-activated protein kinase (MAPK) 1 and transforming growth factor-beta receptors (TGFBR) 1 and TGFBR2 genes and inhibit the expressions of these genes. Our findings suggested that miR-130a-3p might represent as the potential candidate biomarker and therapeutic target for the prognosis identification and treatment of schistosomiasis liver fibrosis.

Advanced Functional Materials Based on Nanocellulose for Pharmaceutical/Medical Applications

Nanocelluloses (NCs), with their remarkable characteristics, have proven to be one of the most promising "green" materials of our times and have received special attention from researchers in nanomaterials. A diversity of new functional materials with a wide range of biomedical applications has been designed based on the most desirable properties of NCs, such as biocompatibility, biodegradability, and their special physicochemical properties. In this context and under the pressure of rapid development of this field, it is imperative to synthesize the successes and the new requirements in a comprehensive review. The first part of this work provides a brief review of the characteristics of the NCs (cellulose nanocrystals-CNC, cellulose nanofibrils-CNF, and bacterial nanocellulose-BNC), as well as of the main functional materials based on NCs (hydrogels, nanogels, and nanocomposites). The second part presents an extensive review of research over the past five years on promising pharmaceutical and medical applications of nanocellulose-based materials, which have been discussed in three important areas: drug-delivery systems, materials for wound-healing applications, as well as tissue engineering. Finally, an in-depth assessment of the in vitro and in vivo cytotoxicity of NCs-based materials, as well as the challenges related to their biodegradability, is performed.

Identification of a potent ionizable lipid for efficient macrophage transfection and systemic anti-interleukin-1β siRNA delivery against acute liver failure

RNA interference (RNAi) therapy has great potential for treating inflammatory diseases. However, the development of potent carrier materials for delivering siRNA to macrophages is challenging. Herein, we design a set of ionizable lipid nanoparticles (LNPs) to screen and identify a potent carrier of siRNA for silencing an essential pro-inflammatory cytokine, interleukin-1β (IL-1β) in macrophages. The top performance LNP (114-LNP), containing ionizable lipid with spermine as an amine-head group, facilitated efficient siRNA internalization via multiple endocytosis pathways and achieved effective endosome escape in macrophages. The optimized LNP/siIL-1β achieved strong silencing of IL-1β in both activated Raw 264.7 cells and primary macrophages. Furthermore, systematic administration of 114-LNP/siIL-1β complexes could effectively inhibit IL-1β expression in an acute liver failure model and significantly attenuated hepatic inflammation and liver damage. These results suggest that the optimized ionizable lipid nanoparticle represents a promising platform for anti-inflammation therapies.

Bio-Orthogonal Nanogels for Multiresponsive Release

Responsive nanogel systems are interesting for the drug delivery of bioactive molecules due to their high stability in aqueous media. The development of nanogels that are able to respond to biochemical cues and compatible with the encapsulation and the release of large and sensitive payloads remains challenging. Here, multistimuli-responsive nanogels were synthesized using a bio-orthogonal and reversible reaction and were designed for the selective release of encapsulated cargos in a spatiotemporally controlled manner. The nanogels were composed of a functionalized polysaccharide cross-linked with pH-responsive hydrazone linkages. The effect of the pH value of the environment on the nanogels was fully reversible, leading to a reversible control of the release of the payloads and a “stop-and-go” release profile. In addition to the pH-sensitive nature of the hydrazone network, the dextran backbone can be degraded through enzymatic cleavage. Furthermore, the cross-linkers were designed to be responsive to oxidoreductive cues. Disulfide groups, responsive to reducing environments, and thioketal groups, responsive to oxidative environments, were integrated into the nanogel network. The release of model payloads was investigated in response to changes in the pH value of the environment or to the presence of reducing or oxidizing agents.

Strategies to load therapeutics into polysaccharide-based nanogels with a focus on microfluidics: A review

Nowadays nanoparticles are increasingly investigated for the targeted and controlled delivery of therapeutics, as suggested by the high number of research articles (2400 in 2000 vs 8500 in 2020). Among them, almost 2% investigated nanogels in 2020. Nanogels or nanohydrogels (NGs) are nanoparticles formed by a swollen three-dimensional network of synthetic polymers or natural macromolecules such as polysaccharides. NGs represent a highly versatile nanocarrier, able to deliver a number of therapeutics. Currently, NGs are undergoing clinical trials for the delivery of anti-cancer vaccines. Herein, the strategies to load low molecular weight drugs, (poly)peptides and genetic material into polysaccharide NGs as well as to formulate NGs-based vaccines are summarized, with a focus on the microfluidics approach.

Glycosaminoglycans: Carriers and Targets for Tailored Anti-Cancer Therapy

The tumor microenvironment (TME) is composed of cancerous, non-cancerous, stromal, and immune cells that are surrounded by the components of the extracellular matrix (ECM). Glycosaminoglycans (GAGs), natural biomacromolecules, essential ECM, and cell membrane components are extensively altered in cancer tissues. During disease progression, the GAG fine structure changes in a manner associated with disease evolution. Thus, changes in the GAG sulfation pattern are immediately correlated to malignant transformation. Their molecular weight, distribution, composition, and fine modifications, including sulfation, exhibit distinct alterations during cancer development. GAGs and GAG-based molecules, due to their unique properties, are suggested as promising effectors for anticancer therapy. Considering their participation in tumorigenesis, their utilization in drug development has been the focus of both industry and academic research efforts. These efforts have been developing in two main directions; (i) utilizing GAGs as targets of therapeutic strategies and (ii) employing GAGs specificity and excellent physicochemical properties for targeted delivery of cancer therapeutics. This review will comprehensively discuss recent developments and the broad potential of GAG utilization for cancer therapy.

Polyamine-Functionalized 2'-Amino-LNA in Oligonucleotides: Facile Synthesis of New Monomers and High-Affinity Binding towards ssDNA and dsDNA

Attachment of cationic moieties to oligonucleotides (ONs) promises not only to increase the binding affinity of antisense ONs by reducing charge repulsion between the two negatively charged strands of a duplex, but also to augment their in vivo stability against nucleases. In this study, polyamine functionality was introduced into ONs by means of 2'-amino-LNA scaffolds. The resulting ONs exhibited efficient binding towards ssDNA, ssRNA and dsDNA targets, and the 2'-amino-LNA analogue carrying a triaminated linker showed the most pronounced duplex- and triplex-stabilizing effect. Molecular modelling revealed that favourable conformational and electrostatic effects led to salt-bridge formation between positively charged polyamine moieties and the Watson-Hoogsteen groove of the dsDNA targets, resulting in the observed triplex stabilization. All the investigated monomers showed increased resistance against 3'-nucleolytic digestion relative to the non-functionalized controls.

Protective Effects of Epigallocatechin Gallate (EGCG) on Endometrial, Breast, and Ovarian Cancers

Green tea and its major bioactive component, (-)-epigallocatechin gallate (EGCG), possess diverse biological properties, particularly antiproliferation, antimetastasis, and apoptosis induction. Many studies have widely investigated the anticancer and synergistic effects of EGCG due to the side effects of conventional cytotoxic agents. This review summarizes recent knowledge of underlying mechanisms of EGCG on protective roles for endometrial, breast, and ovarian cancers based on both in vitro and in vivo animal studies. EGCG has the ability to regulate many pathways, including the activation of nuclear factor erythroid 2-related factor 2 (Nrf2), inhibition of nuclear factor-κB (NF-κB), and protection against epithelial-mesenchymal transition (EMT). EGCG has also been found to interact with DNA methyltransferases (DNMTs) and histone deacetylases (HDACs), which affect epigenetic modifications. Finally, the action of EGCG may exert a suppressive effect on gynecological cancers and have beneficial effects on auxiliary therapies for known drugs. Thus, future clinical intervention studies with EGCG will be necessary to more and clear evidence for the benefit to these cancers.

Alginate-Based Platforms for Cancer-Targeted Drug Delivery

As an acidic, ocean colloid polysaccharide, alginate is both a biopolymer and a polyelectrolyte that is considered to be biocompatible, nontoxic, nonimmunogenic, and biodegradable. A significant number of studies have confirmed the potential use of alginate-based platforms as effective vehicles for drug delivery for cancer-targeted treatment. In this review, the focus is on the formation of alginate-based cancer-targeted delivery systems. Specifically, some general chemical and physical properties of alginate and different types of alginate-based delivery systems are discussed, and various kinds of alginate-based carriers are introduced. Finally, recent innovative strategies to functionalize alginate-based vehicles for cancer targeting are described to highlight research towards the optimization of alginate.

RNA Interference Nanotherapeutics for Treatment of Glioblastoma Multiforme

Nucleic acid therapeutics for RNA interference (RNAi) are gaining attention in the treatment and management of several kinds of the so-called "undruggable" tumors via targeting specific molecular pathways or oncogenes. Synthetic ribonucleic acid (RNAs) oligonucleotides like siRNA, miRNA, shRNA, and lncRNA have shown potential as novel therapeutics. However, the delivery of such oligonucleotides is significantly hampered by their physiochemical (such as hydrophilicity, negative charge, and instability) and biopharmaceutical features (in vivo serum stability, fast renal clearance, interaction with extracellular proteins, and hindrance in cellular internalization) that markedly reduce their biological activity. Recently, several nanocarriers have evolved as suitable non-viral vectors for oligonucleotide delivery, which are known to either complex or conjugate with these oligonucleotides efficiently and also overcome the extracellular and intracellular barriers, thereby allowing access to the tumoral micro-environment for the better and desired outcome in glioblastoma multiforme (GBM). This Review focuses on the up-to-date advancements in the field of RNAi nanotherapeutics utilized for GBM treatment.

Influence of the Core Formulation on Features and Drug Delivery Ability of Carbamate-Based Nanogels

In the last years, nanogels have emerged as one of the most promising classes of novel drug delivery vehicles since they can be employed in multiple fields, such as various therapeutics or diagnostics, and with different classes of compounds and active molecules. Their features, such as a high volume to surface ratio, excellent drug loading and release ability, as well as biocompatibility and tunable behavior, are unique, and, nowadays, great efforts are made to develop new formulations that can be employed in a wider range of applications. Polyethylene glycol (PEG)-polyethylenimine (PEI) nanogels probably represent the baseline of this class of biomaterials and they are still largely employed and studied. In any way, the possibility to exploit new core formulations for nanogels is certainly very interesting in order to understand the influence of different polymer chains on the final properties of the system. In this research, we explore and make a comparison between PEG-PEI nanogels and two other different formulations: pluronic F127-PEI nanogels and PEG-Jeffamine nanogels. We propose nanogels synthesis methods, their chemical and physical characterization, as well as their stability analysis, and we focus on the different drug delivery ability that these structures exhibit working with different typologies of drug mimetics.

Straightforward Access to Glycosylated, Acid Sensitive Nanogels by Host-Guest Interactions with Sugar-Modified Pillar[5]arenes

The introduction of specific targeting units to polymer nanogels usually requires tedious chemical modifications, which limits flexibility in the design of combinatorial approaches. Here, we present a straightforward and versatile method to reversibly introduce various carbohydrate-based targeting units to a pH-sensitive nanogel via host-guest interactions. Glucose-, mannose-, or fructose-modified pillar[5]arenes can adaptably and conveniently be introduced to the surface of the nanogel. Binding studies between these nanogels and the lectin Concanavalin A revealed a high selectivity and strong interaction with only the mannose-modified nanogels. With the addition of other pillar[5]arenes, the interaction can be influenced proving a dynamic exchange of the targeting units. In comparison with common covalent modifications of polymer nanostructures, the presented combination of straightforward precipitation polymerization and supramolecular interactions promises convenient access to adaptable nanostructures for high-throughput screening of targeted delivery systems.

Coarse-grained Monte Carlo simulations of nanogel-polyelectrolyte complexes: electrostatic effects

Coarse-grained Monte-Carlo simulations of nanogel-polyelectrolyte complexes have been carried out. The results presented here capture two phenomena reported in experiments with real complexes: (i) the reduction in size after absorbing just a few chains and (ii) the charge inversion detected through electrophoretic mobility data. Our simulations reveal that charge inversion occurs if the polyelectrolyte charge is large enough. In addition, the distribution of chains inside the nanogel strongly depends on whether charge inversion takes place. It should also be stressed that the chain topology has little influence on most of the properties studied here.

Cell membrane-engineered hybrid soft nanocomposites for biomedical applications

An overview of various cell membrane-engineered hybrid soft nanocomposites for medical applications.

Surface Activity of Smart Hybrid Polysiloxane-co-N-isopropylacrylamide Microgels

Amphiphilic smart gels of different sizes (macro, micro, and nano) are widely used in advanced medical, industrial, and environmental applications. They are sensitive, responsive to different environments, and possess a high surface activity to adsorb onto different interfaces. In this study, new amphiphilic alkoxysilane-containing microgels, hybrid polysiloxane microgel, and silica nanoparticles were prepared using a cross-linking surfactant-free cross-linking polymerization technique for N-isopropylacrylamide (NIPAm) and 2-acrylamido-2-methylpropane sulfonic acid (AMPS) monomers. Vinyltrimethoxysilane (VTS) was used as a silane precursor in the cross-linking polymerization to hydrolyze with tetraethoxysilane (TEOS) in ammonia using an emulsion technique, to create polysiloxane microgel and silica nanoparticles. The surface activity measurements confirmed that NIPAm/VTS had a higher surface activity than NIPAm/AMPS-VTS microgels and their hybrid polysiloxane microgel owing to the differences of the cross-linking of microgels from the center to the microgel periphery, which alter their morphologies.

Development of a safe and efficient gene delivery system based on a biodegradable tannic acid backbone

Finding a safe and efficient gene delivery vector is a major international challenge facing the development of gene therapy. Tannic acid (TA) is a natural cross-linker owing to its hydroxyl and carboxyl groups that can interact with biopolymers for different biomaterial design. In this work, three polyethyleneimine-modified TA polymers were prepared, and the polymers were characterized by FTIR, UV-vis, elemental analysis and ¹H NMR. The potential of PTAs as gene vector was studied in vitro, including DNA loading capacity, DNA protection ability and biocompatibility. In addition, the particle size, zeta potential, DNA encapsulation efficiency, cell uptake and transfection efficiency of the PTA-pDNA polyplexes were also studied. The results showed that PTA2k and PTA30k could completely condense DNA at N/P of 2, and PTA600 could only completely condense DNA at N/P of 50. The PTA/pDNA polyplexes could protect DNA from degrading by DNA enzymes and could be efficiently uptaked by cells. Biocompatibility assay showed that PTA had no significant cytotoxicity and effect on cell proliferation compared to PEI. At low N/P ratios of 1-4, PTA showed higher transfection efficiency than PEI, and the transfection efficiency increased with the increase of PEI molecular weight in PTA. At N/P of 3, PTA30k showed the highest transfection efficiency of 23.8%, while PEI30k showed only 6.7%. These results indicate that PTA is a promising candidate vector for safe and efficient gene delivery.

Recent Advances in Degradable Hybrids of Biomolecules and NGs for Targeted Delivery

Recently, the fast development of hybrid nanogels dedicated to various applications has been seen. In this context, nanogels incorporating biomolecules into their nanonetworks are promising innovative carriers that gain great potential in biomedical applications. Hybrid nanogels containing various types of biomolecules are exclusively designed for: improved and controlled release of drugs, targeted delivery, improvement of biocompatibility, and overcoming of immunological response and cell self-defense. This review provides recent advances in this rapidly developing field and concentrates on: (1) the key physical consequences of using hybrid nanogels and introduction of biomolecules; (2) the construction and functionalization of degradable hybrid nanogels; (3) the advantages of hybrid nanogels in controlled and targeted delivery; and (4) the analysis of the specificity of drug release mechanisms in hybrid nanogels. The limitations and future directions of hybrid nanogels in targeted specific- and real-time delivery are also discussed.