Polymer assembly: Promising carriers as co-delivery systems for cancer therapy

Advances in nanotechnology for targeting cancer-associated fibroblasts: A review of multi-strategy drug delivery and preclinical insights

Cancer-associated fibroblasts (CAFs) play a crucial role in the tumor microenvironment by promoting tumor growth, immune evasion, and metastasis. Recently, drug delivery systems targeting CAFs have emerged as a promising long-term and effective approach to cancer treatment. Advances in nanotechnology, in particular, have led to the development of nanomedicine delivery systems designed specifically to target CAFs, offering new possibilities for precise and personalized cancer therapies. This article reviews recent progress in drug delivery using nanocarriers that target CAFs. Additionally, we explore the potential of combining multiple therapies, such as chemotherapy and immunotherapy, with nanocarriers to enhance efficacy and overcome drug resistance. Although many preclinical studies show promise, the clinical application of nanomedicine still faces considerable challenges, especially in terms of drug penetration and large-scale production. Therefore, this review aims to provide a fresh perspective on CAF-targeted drug delivery systems and highlight potential future research directions and clinical applications.

Co-delivery of PROTAC and siRNA via novel liposomes for the treatment of malignant tumors

Targeted elimination of damaged or overexpressed proteins within the tumor serves a pivotal role in regulating cellular function and restraining tumor cell growth. Researchers have been striving to identify safer and more effective methods for protein removal. Here, we propose the synergistic employment of a small molecule degrading agent (PROTAC) and siRNA to attain enhanced protein clearance efficiency and tumor therapeutic effects. Co-delivery liposomes were prepared to facilitate the efficient encapsulation of PROTAC and siRNA. Specifically, the cationic liposome significantly improved the solubility of the insoluble PROTAC (DT2216). The cationic polymer (F-PEI) achieved efficient encapsulation of the nucleic acid drug, thereby promoting endocytosis and enhancing the therapeutic impact of the drug. Both in vivo and in vitro experiments demonstrated remarkable degradation of target proteins and inhibition of tumor cells by the co-delivery system. In conclusion, the co-delivery liposomes furnished a nano-delivery system proficient in effectively encapsulating both hydrophilic and hydrophobic drugs, thereby presenting a novel strategy for targeted combination therapy in treating tumors.

The role of lipid particle-laden interfaces in regulating the co-delivery of two hydrophobic actives from o/w emulsions

Co-delivery strategies have become an integral active delivery approach, although understanding of how the microstructural characteristics could be deployed to achieve independently regulated active co-delivery profiles, is still an area at its infancy. Herein, the capacity to provide such control was explored by utilizing Pickering emulsions stabilized by lipid particles, namely solid lipid nanoparticles (SLNs) and nanostructured lipid carriers (NLCs). These dual functional species, regarding their concurrent Pickering stabilization and active carrying/delivery capabilities, were formulated with different solid lipid and surfactant types, and the effect on the release and co-release modulation of two hydrophobic actives separately encapsulated within the lipid particles themselves and within the emulsion droplets was investigated. Disparities between the release profiles from the particles in aqueous dispersions or at an emulsion interface, were related to the specific lipid matrix composition. Particles composed of lipids with higher oil phase compatibility of the emulsion droplets were shown to exert less control over their release regulation ability, as were particles in the presence of surfactant micelles in the continuous phase. Irrespective of their formulation characteristics, all particles provided a level of active release control from within the emulsion droplets, which was dependant on the permeability of the formed interfacial layer. Specifically, use of a bulkier particle surfactant or particle sintering at the droplet interface resulted in more sustained droplet release rates. Compared to sole release, the co-release performance remained unaffected by the co-existence of the two hydrophobic actives with the co-release behavior persisting over a storage period of 1 month.

Magnetically Active Bicontinuous Polymer Structures for Multiple Controlled Drug Delivery

The targeted delivery of drugs using wireless navigable magnetic robots allows the delivery of drug molecules to be controlled non only in time but also in space, improving medical outcomes. The main disadvantages behind their use lies in the low amount of drug that can be transported and the single nature of drug that can be loaded (hydrophilic or hydrophobic). These considerations limit their use in co-delivery systems, now recognized to be very promising for many different pathologies. A magnetic bijel-like structure is developed to load and release different types of molecules (hydrophilic and hydrophobic). In this work, the use of ε-caprolactone is explored, which can polymerize, forming hydrophobic domains (oil phase). After mixing with iron oxide nanoparticles (NPs), the water dispersion creates a magnetic biphasic porous structure without phase separation. The resulting device shows good performance both in magnetic actuation and as a drug delivery system.

Benznidazole-Loaded Polymeric Nanoparticles for Oral Chemotherapeutic Treatment of Chagas Disease

Chagas disease (CD) is a worldwide public health problem. Benznidazole (BZ) is the drug used to treat it. However, in its commercial formulation, it has significant side effects and is less effective in the chronic phase of the infection. The development of particulate systems containing BZ is therefore being promoted. The objective of this investigation was to develop polymeric nanoparticles loaded with BZ and examine their trypanocidal impact in vitro. Two formulas (BNP1 and BNP2) were produced through double emulsification and freeze drying. Subsequent to physicochemical and morphological assessment, both formulations exhibited adequate yield, average particle diameter, and zeta potential for oral administration. Cell viability was assessed in H9C2 and RAW 264.7 cells in vitro, revealing no cytotoxicity in cardiomyocytes or detrimental effects in macrophages at specific concentrations. BNP1 and BNP2 enhanced the effect of BZ within 48 h using a treatment of 3.90 μg/mL. The formulations notably improved NO reduction, particularly BNP2. The findings imply that the compositions are suitable for preclinical research, underscoring their potential as substitutes for treating CD. This study aids the quest for new BZ formulations, which are essential in light of the disregard for the treatment of CD and the unfavorable effects associated with its commercial product.

Injectable Thermoresponsive Microparticle/Hydrogel System with Superparamagnetic Nanoparticles for Drug Release and Magnetic Hyperthermia Applications

Cancer is a disease that continues to greatly impact our society. Developing new and more personalized treatment options is crucial to decreasing the cancer burden. In this study, we combined magnetic polysaccharide microparticles with a Pluronic thermoresponsive hydrogel to develop a multifunctional, injectable drug delivery system (DDS) for magnetic hyperthermia applications. Gellan gum and alginate microparticles were loaded with superparamagnetic iron oxide nanoparticles (SPIONs) with and without coating. The magnetic microparticles' registered temperature increases up to 4 °C upon the application of an alternating magnetic field. These magnetic microparticles were mixed with drug-loaded microparticles, and, subsequently, this mixture was embedded within a Pluronic thermoresponsive hydrogel that is capable of being in the gel state at 37 °C. The proposed DDS was capable of slowly releasing methylene blue, used as a model drug, for up to 9 days. The developed hydrogel/microparticle system had a smaller rate of drug release compared with microparticles alone. This system proved to be a potential thermoresponsive DDS suitable for magnetic hyperthermia applications, thus enabling a synergistic treatment for cancer.

Seeded RAFT Polymerization-Induced Self-assembly: Recent Advances and Future Opportunities

Over the past decade, polymerization-induced self-assembly (PISA) has fully proved its versatility for scale-up production of block copolymer nanoparticles with tunable sizes and morphologies; yet, there are still some limitations. Recently, seeded PISA approaches combing PISA with heterogeneous seeded polymerizations have been greatly explored and are expected to overcome the limitations of traditional PISA. In this review, recent advances in seeded PISA that have expanded new horizons for PISA are highlighted including i) general considerations for seeded PISA (e.g., kinetics, the preparation of seeds, the selection of monomers), ii) morphological evolution induced by seeded PISA (e.g., from corona-shell-core nanoparticles to vesicles, vesicles-to-toroid, disassembly of vesicles into nanospheres), and iii) various well-defined nanoparticles with hierarchical and sophisticated morphologies (e.g., multicompartment micelles, porous vesicles, framboidal vesicles, AXn -type colloidal molecules). Finally, new insights into seeded PISA and future perspectives are proposed.

A comprehensive review of protein-based carriers with simple structures for the co-encapsulation of bioactive agents

The rational design and fabrication of edible codelivery carriers are important to develop functional foods fortified with a plurality of bioactive agents, which may produce synergistic effects in increasing bioactivity and functionality to target specific health benefits. Food proteins possess considerable functional attributes that make them suitable for the delivery of a single bioactive agent in a wide range of platforms. Among the different types of protein-based carriers, protein-ligand nanocomplexes, micro/nanoparticles, and oil-in-water (O/W) emulsions have increasingly attracted attention in the codelivery of multiple bioactive agents, due to the simple and convenient preparation procedure, high stability, matrix compatibility, and dosage flexibility. However, the successful codelivery of bioactive agents with diverse physicochemical properties by using these simple-structure carriers is a daunting task. In this review, some effective strategies such as combined functional properties of proteins, self-assembly, composite, layer-by-layer, and interfacial engineering are introduced to redesign the carrier structure and explore the encapsulation of multiple bioactive agents. It then highlights success stories and challenges in the co-encapsulation of multiple bioactive agents within protein-based carriers with a simple structure. The partition, protection, and release of bioactive agents in these protein-based codelivery carriers are considered and discussed. Finally, safety and application as well as challenges of co-encapsulated bioactive agents in the food industry are also discussed. This work provides a state-of-the-art overview of protein-based particles and O/W emulsions in co-encapsulating bioactive agents, which is essential for the design and development of novel functional foods containing multiple bioactive agents.

TPGS Decorated Liposomes as Multifunctional Nano-Delivery Systems

Liposomes are sphere-shaped vesicles that can capture therapeutics either in the outer phospholipid bilayer or inner aqueous core. Liposomes, especially when surface-modified with functional materials, have been used to achieve many benefits in drug delivery, including improving drug solubility, oral bioavailability, pharmacokinetics, and delivery to disease target sites such as cancers. Among the functional materials used to modify the surface of liposomes, the FDA-approved non-ionic surfactant D-alpha-tocopheryl polyethylene glycol succinate (TPGS) is increasingly being applied due to its biocompatibility, lack of toxicity, applicability to various administration routes and ability to enhance solubilization, stability, penetration and overall pharmacokinetics. TPGS decorated liposomes are emerging as a promising drug delivery system for various diseases and are expected to enter the market in the coming years. In this review article, we focus on the multifunctional properties of TPGS-coated liposomes and their beneficial therapeutic applications, including for oral drug delivery, vaccine delivery, ocular administration, and the treatment of various cancers. We also suggest future directions to optimise the manufacture and performance of TPGS liposomes and, thus, the delivery and effect of encapsulated diagnostics and therapeutics.

Physically stimulus-responsive nanoparticles for therapy and diagnosis

Nanoparticles offer numerous advantages in various fields of science, particularly in medicine. Over recent years, the use of nanoparticles in disease diagnosis and treatments has increased dramatically by the development of stimuli-responsive nano-systems, which can respond to internal or external stimuli. In the last 10 years, many preclinical studies were performed on physically triggered nano-systems to develop and optimize stable, precise, and selective therapeutic or diagnostic agents. In this regard, the systems must meet the requirements of efficacy, toxicity, pharmacokinetics, and safety before clinical investigation. Several undesired aspects need to be addressed to successfully translate these physical stimuli-responsive nano-systems, as biomaterials, into clinical practice. These have to be commonly taken into account when developing physically triggered systems; thus, also applicable for nano-systems based on nanomaterials. This review focuses on physically triggered nano-systems (PTNSs), with diagnostic or therapeutic and theranostic applications. Several types of physically triggered nano-systems based on polymeric micelles and hydrogels, mesoporous silica, and magnets are reviewed and discussed in various aspects.

Polyoxometalate-based nanocomposites for antitumor and antibacterial applications

Polyoxometalates (POMs), as emerging inorganic metal oxides, have been shown to have significant biological activity and great medicinal value. Nowadays, biologically active POM-based organic-inorganic hybrid materials have become the next generation of antibacterial and anticancer drugs because of their customizable molecular structures related to their highly enhanced antitumor activity and reduced toxicity to healthy cells. In this review, the current developed strategies with POM-based materials for the purpose of antibacterial and anticancer activities from different action principles inducing cell death and hyperpolarization, cell plasma membrane destruction, interference with bacterial respiratory chain and inhibiting bacterial growth are overviewed. Moreover, specific interactions between POM-based materials and biomolecules are highlighted for a better understanding of their antibacterial and anticancer mechanisms. POMs have great promise as next-generation antibacterial and anticancer drugs, and this review will provide a valuable systematic reference for the further development of POM-based nanomaterials.

Poly(methacrylate citric acid) as a Dual Functional Carrier for Tumor Therapy

Owing to its pH-sensitive property and chelating Cu²⁺ effect, poly(methacrylate citric acid) (PCA) can be utilized as a dual functional nanocarrier to construct a nanodelivery system. Negatively charged carboxyl groups can interact with positively charged antineoplastic drugs through electrostatic interaction to form stable drug nanoparticles (NPs). Through drug experimental screening, doxorubicin (DOX) was selected as the model drug, PCA/DOX NPs with a diameter of 84 nm were prepared, and the drug-loading content was 68.3%. PCA/DOX NPs maintained good stability and a sustained release profile. Cell experiments presented that PCA/DOX NPs could inhibit effectively the growth of 4T1 cells; the IC₅₀ value was decreased by approximately 15-fold after incubation for 72 h. The cytotoxicity toward H9C2 was decreased significantly. Moreover, based on its ability to efficiently adsorb copper ions, PCA showed good vascular growth inhibition effect in vitro. Furthermore, animal experiments showed that PCA/DOX NPs presented stronger anticancer effects than DOX; the tumor inhibition rate was increased by 1.5-fold. Myocardial toxicity experiments also confirmed that PCA reduced the cardiotoxicity of DOX. In summary, PCA/DOX NPs show good antitumor efficacy and low toxicity, and have good potential for clinical application.

Polyelectrolyte/surfactant films: from 2D to 3D structural control

Reversible control of the 3D structure of polyelectrolyte/surfactant films at the air/water interface is showcased. A recently discovered mechanism is exploited to form highly efficient, stable and biocompatible films by...

Co-encapsulation of quercetin and resveratrol in zein/carboxymethyl cellulose nanoparticles: characterization, stability and in vitro digestion

Formation and investigation of zein/carboxymethyl cellulose composite nanoparticles to co-deliver quercetin and resveratrol.

Systematic Combination of Oligonucleotides and Synthetic Polymers for Advanced Therapeutic Applications

The potential of oligonucleotides is exceptional in therapeutics because of their high safety, potency, and specificity compared to conventional therapeutic agents. However, many obstacles, such as low in vivo stability and poor cellular uptake, have hampered their clinical success. Use of polymeric carriers can be an effective approach for overcoming the biological barriers and thereby maximizing the therapeutic efficacy of the oligonucleotides due to the availability of highly tunable synthesis and functional modification of various polymers. As loaded in the polymeric carriers, the therapeutic oligonucleotides, such as antisense oligonucleotides, small interfering RNAs, microRNAs, and even messenger RNAs, become nuclease-resistant by bypassing renal filtration and can be efficiently internalized into disease cells. In this review, we introduced a variety of systematic combinations between the therapeutic oligonucleotides and the synthetic polymers, including the uses of highly functionalized polymers responding to a wide range of endogenous and exogenous stimuli for spatiotemporal control of oligonucleotide release. We also presented intriguing characteristics of oligonucleotides suitable for targeted therapy and immunotherapy, which can be fully supported by versatile polymeric carriers.

Red Light-Emitting Water-Soluble Luminescent Iridium-Containing Polynorbornenes: Synthesis, Characterization and Oxygen Sensing Properties in Biological Tissues In Vivo

New water-soluble polynorbornenes P1-P4 containing oligoether, amino acid groups and luminophoric complexes of iridium(III) were synthesized by ring-opening metathesis polymerization. The polymeric products in organic solvents and in water demonstrate intense photoluminescence in the red spectral region. The polymers P1 and P3 with 1-phenylisoquinoline cyclometalating ligands in iridium fragments reveal 4-6 fold higher emission quantum yields in solutions than those of P2 and P4 that contain iridium complexes with 1-(thien-2-yl)isoquinoline cyclometalating ligands. The emission parameters of P1-P4 in degassed solutions essentially differ from those in the aerated solutions showing oxygen-dependent quenching of phosphorescence. Biological testing of P1 and P3 demonstrates that the polymers do not penetrate into live cultured cancer cells and normal skin fibroblasts and do not possess cytotoxicity within the concentrations and time ranges reasonable for biological studies. In vivo, the polymers display longer phosphorescence lifetimes in mouse tumors than in muscle, as measured using phosphorescence lifetime imaging (PLIM), which correlates with tumor hypoxia. Therefore, preliminary evaluation of the synthesized polymers shows their suitability for noninvasive in vivo assessments of oxygen levels in biological tissues.

A systematic review of functionalized polymeric nanoparticles to improve intestinal permeability of drugs and biological products

BACKGROUND

The oral route is the most frequently used and the most convenient route of drug administration, since it has several advantages, such as ease of use, patient compliance and better cost-effectiveness. However, physicochemical and biopharmaceutical limitations of various active pharmaceutical ingredients (API) hinder suitability for this route, including degradation in the gastrointestinal tract, low intestinal permeability and low bioavailability. To overcome these problems, while maintaining therapeutic efficacy, polymeric nanoparticles have attracted considerable attention for their ability to increase drug solubility, promote controlled release, and improve stability. In addition, the functionalization of nanocarriers can increase uptake and accumulation at the target site of action, and intestinal absorption, making it possible to obtain more viable, safe and efficient treatments for oral administration. <P> Objective: This systematic review aimed to seek recent advances in the literature on the use of polymeric nanoparticles functionalization to increase intestinal permeability of APIs that are intended for oral administration. <P> Method: Two bibliographic databases were consulted (PubMed and ScienceDirect). The selected publications and the writing of this systematic review were based on the guidelines mentioned in the PRISMA statement. <P> Results: Out of a total of 3036 studies, 22 studies were included in this article based on our eligibility criteria. The results were consistent for the application of nanoparticle functionalization to increase intestinal permeability. <P> Conclusion: The functionalized polymeric nanoparticles can be considered as carrier systems that improve the intestinal permeability and bioavailability of APIs, with the potential to result, in the future, in the development of oral medicines.

Novel multi-stimuli responsive functionalized PEG-based co-delivery nanovehicles toward sustainable treatments of multidrug resistant tumor

The efficacy of ongoing anticancer treatment is often compromised by some barriers, such as low drug content, nonspecific release of drug delivery system, and multidrug resistance (MDR) effect of tumors. Herein, in the research a novel functionalized PEG-based polymer cystine-(polyethylene glycol)2-b-(poly(2-methacryloyloxyethyl ferrocenecarboxylate)2) (Cys-(PEG45)2-b-(PMAOEFC)2) with multi-stimuli sensitive mechanism was constructed, in which doxorubicin (DOX) was chemical bonded through Schiff base structure to provide acid labile DOX prodrug (DOX)2-Cys-(PEG45)2-b-(PMAOEFC)2. Afterwards, paclitaxel (PTX) and its diselenide bond linked PTX dimer were encapsulated into the prodrug through physical loading, to achieve pH and triple redox responsive (DOX)2-Cys-(PEG45)2-b-(PMAOEFC)2@PTX and (DOX)2-Cys-(PEG45)2-b-(PMAOEFC)2@PTX dimer with ultrahigh drugs content. The obtained nanovehicles could self-assemble into globular micelles with good stability based on fluorescence spectra and TEM observation. Moreover, there was a remarkable "reassembly-disassembly" behavior caused by phase transition of micelles under the mimic cancerous physiological environment. DOX and PTX could be on-demand released in acid and redox stress mode, respectively. Meanwhile, in vivo anticancer studies revealed the significant tumor inhibition of nanoformulas. This work offered facile strategies to fabricate drug nanaovehicles with tunable drug content and types, it has a profound significance in overcoming MDR effect, which provided more options for sustainable cancer treatment according to the desired drug dosage and the stage of tumor growth.

Ionic Liquid-Controlled Shape Transformation of Spherical to Nonspherical Polymersomes via Hierarchical Self-Assembly of a Diblock Copolymer

Here, we report the self-assembly of poly(ethylene glycol) methyl ether-block-poly(ε-caprolactone) (PEG-b-PCL) copolymer in three ionic liquids (ILs) possessing different cations with common bis(trifluoromethylsulfonyl)imide anion. The observed polymeric nanostructures in ILs were directly visualized by room temperature conventional transmission and field emission scanning electron microscopy and were further examined for their size and shape by dynamic light scattering technique. The results show that through changes in the concentration of PEG-b-PCL and/or changing the solvent by using a different IL, we can effectively induce shape transformation of self-assembled PEG-b-PCL nanostructures in order to generate nonspherical polymersomes, such as worm-like aggregates, stomatocytes, nanotubes, large hexagonal and tubular-shaped polymersomes. These findings provide a promising platform for the design of biodegradable soft dynamic systems in the micro-/nano-motor field for cancer-targeted delivery, diagnosis and imaging-guided therapy, and controlled release of therapeutic drugs for treatment of many diseases. Non-spherical polymersome-based vaccines may be taken up more efficiently, especially against viruses for pulmonary drug delivery than the spherical polymersomes-based.

COVID-19 infection and nanomedicine applications for development of vaccines and therapeutics: An overview and future perspectives based on polymersomes

The severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), which emerged in December 2019 and caused the coronavirus disease 2019 (COVID-19) pandemic, took the world by surprise with an unprecedented public health emergency. Since this pandemic began, extraordinary efforts have been made by scientists to understand the pathogenesis of COVID-19, and to fight the infection by providing various preventive, diagnostic and treatment opportunities based on either novel hypotheses or past experiences. Despite all the achievements, COVID-19 continues to be an accelerating health threat with no specifically approved vaccine or therapy. This review highlights the recent advances in COVID-19 infection, with a particular emphasis on nanomedicine applications that can help in the development of effective vaccines or therapeutics against COVID-19. A novel future perspective has been proposed in this review based on utilizing polymersome nano-objects for effectively suppressing the cytokine storm, which may reduce the severity of COVID-19 infection.

Hyaluronic acid reduction-sensitive polymeric micelles achieving co-delivery of tumor-targeting paclitaxel/apatinib effectively reverse cancer multidrug resistance

Multidrug resistance (MDR) of cancer cells is a significant challenge in chemotherapy, highlighting the urgent medical need for simple and reproducible strategies to reverse this process. Here, we report the development of an active tumor-targeting and redox-responsive nanoplatform (PA-ss-NP) using hyaluronic acid-g-cystamine dihydrochloride-poly-ε-(benzyloxycarbonyl)-L-lysine (HA-ss-PLLZ) to co-deliver paclitaxel (PTX) and apatinib (APA) for effective reversal of MDR. This smart nanoplatform specifically bound to CD44 receptors, leading to selective accumulation at the tumor site and uptake by MCF-7/ADR cells. Under high concentrations of cellular glutathione (GSH), the nanocarrier was degraded rapidly with complete release of its encapsulated drugs. Released APA effectively inhibited the function of the P-glycoprotein (P-gp) drug pump and improved the sensitivity of MDR cells to chemotherapeutic agents, leading to the recovery of PTX chemosensitivity in MDR cells. As expected, this newly developed intelligent drug delivery system could effectively control MDR, both in vitro and in vivo.

Cathepsin B-responsive and gadolinium-labeled branched glycopolymer-PTX conjugate-derived nanotheranostics for cancer treatment

Multi-modal therapeutics are emerging for simultaneous diagnosis and treatment of cancer. Polymeric carriers are often employed for loading multiple drugs due to their versatility and controlled release of these drugs in response to a tumor specific microenvironment. A theranostic nanomedicine was designed and prepared by complexing a small gadolinium chelate, conjugating a chemotherapeutic drug PTX through a cathepsin B-responsive linker and covalently bonding a fluorescent probe pheophorbide a (Ppa) with a branched glycopolymer. The branched prodrug-based nanosystem was degradable in the tumor microenvironment with overexpressed cathepsin B, and PTX was simultaneously released to exert its therapeutic effect. The theranostic nanomedicine, branched glycopolymer-PTX-DOTA-Gd, had an extended circulation time, enhanced accumulation in tumors, and excellent biocompatibility with significantly reduced gadolinium ion (Gd³⁺) retention after 96 h post-injection. Enhanced imaging contrast up to 24 h post-injection and excellent antitumor efficacy with a tumor inhibition rate more than 90% were achieved from glycopolymer-PTX-DOTA-Gd without obvious systematic toxicity. This branched polymeric prodrug-based nanomedicine is very promising for safe and effective diagnosis and treatment of cancer.

•

A cathepsin B-responsive theranostic nanomedicine (glycopolymer-PTX-DOTA-Gd) based on a branched glycopolymer was prepared.

•

Glycopolymer-PTX-DOTA-Gd can be specifically degradated and release drug at tumor enviornment.

•

Glycopolymer-PTX-DOTA-Gd enhance the contrast of magnetic resonance imaging (MRI) at tumor sites.

•

The nanomedicine have good biocompatibility, excellent tumor targeting and anti-tumor efficacy.

Dissolution of amorphous nifedipine from micelle-forming carboxymethylcellulose derivatives

We show that a novel amphiphilic graft copolymer combining the biodegradability and biocompatibility of oxidized carboxymethylcellulose (CMC) with that of hydrophilic poly(ethylene glycol) (PEG), and hydrophobic dodecylamine (DDA), improves the solubility and dissolution performance of nifedipine (NIF), considered as a model hydrophobic drug. The hydrophobic components of the graft copolymer have the multiple effect of favouring micelle formation and loading. At the same time, the interaction between the hydrophobic core and NIF has the secondary effect to suppress drug crystallization, favouring its dissolution, and to increase photostability. Oxidized CMC-g-PEG-DDA micelles reached values of drug concentration, loading capacity and encapsulation efficiency as high as 340 μg mL^-1, 6.4 % and 34.1 %, respectively. Loaded micelles showed a good stability with a limited release profile at pH 1.2, whereas at pH 7.4 the swollen cores enable much higher and progressive release, that reaches 3.4 and 6.6 % after 3 and 5 h, respectively, corresponding to very competitive concentration of 34 and 66 μg mL^-1.

Cisplatin-loaded albumin nanoparticle and study their internalization effect by using β-cyclodextrin

The present study with aim at enhancing the therapeutic and anti-cancer properties of cisplatin (CPT)-loaded bovine serum albumin (BSA) nanoparticles. The BSA nanoparticles containing CPT (CPT-BSANPs) were successfully prepared by the desolvation technique. The physicochemical characterization of the CPT-BSANPs were used by Fourier transformed infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and atomic force microscopy (AFM). The particle size of CPT-BSANPs was found less than 200 nm with 75.02 ± 0.15% entrapment efficiency (EE), while zeta potential and PDI were -17.6 mV and 0.2, respectively. In vitro release behavior of the CPT from the carrier suggests that about 64% of the drug gets released after 48 hrs. The anti-cancer activities of the CPT-BSANPs were tested on MCF-7 cell lines. Our studies show that CPT-BSANPs nanoparticles showed specific targeting and enhanced cytotoxicity to MCF-7 cells when compared to the bare CPT. Thus results suggest that CPT-BSANPs fallowed caveolae-mediated endocytosis, it may become better option for intracellular delivery of anticancer drug.

In-Depth Study into Polymeric Materials in Low-Density Gastroretentive Formulations

The extensive use of oral dosage forms for the treatment of diseases may be linked to deficient pharmacokinetic properties. In some cases the drug is barely soluble; in others, the rapid transit of the formulation through the gastrointestinal tract (GIT) makes it difficult to achieve therapeutic levels in the organism; moreover, some drugs must act locally due to a gastric pathology, but the time they remain in the stomach is short. The use of formulations capable of improving all these parameters, as well as increasing the resident time in the stomach, has been the target of numerous research works, with low-density systems being the most promising and widely explored, however, there is further scope to improve these systems. There are a vast variety of polymeric materials used in low-density gastroretentive systems and a number of methods to improve the bioavailability of the drugs. This works aims to expedite the development of breakthrough approaches by providing an in-depth understanding of the polymeric materials currently used, both natural and synthetic, their properties, advantages, and drawbacks.

Europium based coordination polyelectrolytes enable core-shell-corona micelles as luminescent probes

Core-shell-corona (CSC) micelles have multiple layers, which can serve as separate compartments. This property allows them to combine multiple functionalities in a single nanoparticle, with obvious application potential. Here, we propose a new type of CSC micelles with an apolar core and a polyelectrolyte complex shell incorporating coordination polymers. We obtain these particles by using a poly(styrene)-b-poly(vinyl pyridine)-b-poly(ethylene oxide) (PS-b-PVP-b-PEO) triblock copolymer with quaternized PVP blocks. This polymer leads to well-defined CSC micelles with a cationic shell, which allows us to entrap anionic coordination polymers without disturbing the micellar structure. Useful properties can be imported in this way, e.g., europium (Eu)-based coordination polymers endow the CSC micelles with strong luminescence. Moreover, copper ions (Cu2+) can quench the luminescence because they disturb the Eu-ligand coordination. Upon adding sulfide ions (S2-), copper ions precipitate as CuS and the Eu-ligand bond as well as the corresponding luminescence are restored. This effect is highly specific for Cu2+ and S2-: other cations or anions hardly interfere with this "on-off-on" luminescence response towards Cu2+ and S2-, demonstrating the selectivity of these CSC micelles as detectors of copper and sulfide ions.

Rational design and latest advances of codelivery systems for cancer therapy

Current treatments have limited effectiveness in treating tumors. The combination of multiple drugs or treatment strategies is widely studied to improve therapeutic effect and reduce adverse effects of cancer therapy. The codelivery system is the key to realize combined therapies. It is necessary to design and construct different codelivery systems in accordance with the variable structures and properties of cargoes and vectors. This review presented the typical design considerations about codelivery vectors for cancer therapy and described the current state of codelivery systems from two aspects: different types of vectors and collaborative treatment strategies. The commonly used loading methods of cargoes into the vectors, including physical and chemical processes, are discussed in detail. Finally, we outline the challenges and perspectives about the improvement of codelivery systems.

Mixed micelles of TPGS and Soluplus® for co-delivery of paclitaxel and fenretinide: in vitro and in vivo anticancer study

Fenretinide (4-HPR), as a semi-synthetic retinoid, has apoptosis-promoting effects as a single agent and chemotherapy synergist in vitro. When a human ovarian cancer cells line (A2780s) was treated with both PTX and 4-HPR, there was a synergistic anti-cancer effect demonstrated with a average combination index of 0.44. In this research, a new TPGS-Soluplus^® mixed micelles were developed which encapsulation efficiencies of paclitaxel (PTX) and fenretinide (4-HPR) were as high as 98%, and the average diameter of the micelles was 66.26 nm. Cytotoxicity of the mixed micelles co-delivered with PTX and 4-HPR reduced significantly 7.3 and 25.1 times compared with free drug respectively in A2780s cells. More importantly, in vivo pharmacokinetic study, the loaded drugs in mixed micelles exhibited higher AUC and t_1/2 values than free drugs. Furthermore, in vivo antitumor efficacy experiments demonstrated that PF-TS exhibited superior in vivo antitumor activity on the inhibition rate of tumor growth than other treatment groups (77.8% corresponding tumor growth inhibition in PF-TS treated group vs 19.9, 12.5, and 26.0% of tumor growth inhibition rate in Taxol^®, 4-HPR, and Taxol^®+4-HPR, respectively). Therefore, the mixed micelles of co-deliver PTX and 4-HPR successfully constructed may hopefully be applied to the cancer combination treatment with less toxic effect and more antitumor activity.

Design, in silico modelling and functionality theory of folate-receptor-targeted myricetin-loaded bovine serum albumin nanoparticle formulation for cancer treatment

Targeted drug delivery systems are a promising field of research. Nano-engineered material-mediated drug delivery possesses remarkable potential for the treatment of various malignancies. Here, folic acid (FA)-conjugated bovine serum albumin (BSA) nanoparticles (NPs) were used to encapsulate myricetin (Myr). Subsequently, the delivery of Myr via naturally overexpressed folate receptor (FR) to FR-positive breast cancer cells was studied. Myr-loaded BSA NPs were assembled by modified desolvation cross-linking technique. An FA-conjugated carrier, N-hydroxysuccinimide (NHS)-FA ester, was successfully synthesized. Its functional and structural characteristics were confirmed by ultraviolet, Fourier-transform infrared, and proton nuclear magnetic resonance spectroscopy. Biocompatible FA-conjugated, Myr-loaded BSA NPs (FA-Myr-BSA NPs) were successfully formulated using a carbonate/bicarbonate buffer. Their morphology, size, shape, physiological stability, and drug release kinetics were studied. Molecular docking studies revealed that FA-Myr-BSA NPs readily bound non-covalently to folate receptors and facilitated active drug endocytosis. FA-Myr-BSA NPs could trigger fast release of Myr in an acidic medium (pH 5.4), and showed high biocompatibility in a physiological medium. FA-Myr-BSA NPs effectively decreased the viability of MCF-7 cells after 24 h with 72.45 μg ml^-1 IC₅₀ value. In addition, FA-Myr-BSA NPs enhanced the uptake of Myr in MCF-7 cells. After incubation, a typical apoptotic morphology of condensed nuclei and distorted membrane bodies was observed. The NPs also targeted mitochondria of MCF-7 cells, significantly increasing reactive oxygen species release and contributing to the loss of mitochondrial membrane integrity. The observed results confirm that the newly developed FA-Myr-BSA NPs can serve as a potential carrier for Myr to increase the anticancer activity of this chemotherapeutic.

Crosslinking Induced Reassembly of Multiblock Polymers: Addressing the Dilemma of Stability and Responsivity

Physical or chemical crosslinking of polymeric micelles has emerged as a straightforward approach to overcome the intrinsic instability of assemblies. However, the crosslinking process may compromise the responsivity of nanosystems and result in inefficient release of payloads. To address this dilemma, a crosslinking induced reassembly (CIRA) strategy is reported here to simultaneously increase the kinetic and thermodynamic stability and redox-responsivity of polymeric micelles. It is found that the click crosslinking of a model multiblock polyurethane at the micellar interface induces microphase separation between the soft and hard segments. The aggregation of hard domains gathers liable disulfide linkages around the interlayer of micelles, which could facilitate the attack of reducing agents and act as an intelligent on-off switch for high stability and triggered release. As a result, the CIRA approach enables an enhanced tumor targeting, improved biodistribution and excellent therapeutic efficacy in vivo. This work provides a facile and versatile platform for controlled delivery applications.

Encapsulation and release of drug nanoparticles in functional polymeric vesicles

We investigated the co-assembly of amphiphilic diblock copolymers in solutions containing drugs and functional nanoparticles using the dissipative particle dynamics (DPD) method. By controlling the size and the concentration of the functional nanoparticles, the length of the hydrophobic blocks, and the interaction parameters between the hydrophobic block/solvent and the functional nanoparticles, we obtained the desired aggregates to load drugs. The aggregates loaded with drugs can be disk-like micelles, sphere-like micelles and vesicles with functional nanoparticles on the surface. When the solvent environment changes, the drugs loaded in the functional vesicles can release into the solvent. The release content is critically dependent on the repulsive interaction between the drugs and the solvent. The dynamic curve of drug release is obtained. The result is in agreement with the experiments about drug release. Our studies showed that we can precisely control the formation of functional vesicles to load and release drugs. Loading drugs in the process of self-assembly and controlling the release have broad potential in the field of clinical medicine and adding functional nanoparticles can be of great help in drug delivery and medical diagnosis.

Controlled Formation of Hydrated Micelles by the Intervention of Cyclodextrins

The interaction between surfactants and cyclodextrins (CDs) is well known. Studies have focused mainly on destruction of micelles with CDs to release the encapsulated drugs. However, less emphasis has been given on understanding the formation of micelles with the CD encapsulated surfactants. We have used fluorescence spectroscopy to study the impact of CDs on micelles using a fluorophore that has been tactically designed as a reporter. This molecule has a pyrene moiety on one end and a cationic head group on the other so that the orientation of the compound can be prefixed on micelle formation in aqueous environment. We have observed that the CD encapsulated surfactants can form "hydrated micelles" that allow extensive penetration of water molecules toward the core. The mechanism for such a process involves inclusion of the hydrophobic surfactant tails within the CD core and participation of these inclusion complexes in micelle formation. The process could be controlled by tuning the concentration of CD. The degree of hydration varies as the micelles get more opened up due to the residence of the CDs inside them.

Ratiometric co-delivery of doxorubicin and docetaxel by covalently conjugating with mPEG-poly(β-malic acid) for enhanced synergistic breast tumor therapy

Ratiometric codelivery of doxorubicin and docetaxel through an engineered nanoconjugate based on mPEG-PMLA facilitates the accumulation of drugs at the tumor site and enhances synergistic antitumor response.

Nanocomposites of ionic copolymer integrating Gd-containing polyoxometalate as a multiple platform for enhanced MRI and pH-response chemotherapy

Nanocomposites from the co-assemblies of block copolymers and a gadolinium-grafting inorganic cluster were constructed as a multifunctional platform for MRI enhancement, drug loading, and environment-response release at local positions.

Development of Traceable Rituximab-Modified PEO-Polyester Micelles by Postinsertion of PEG-phospholipids for Targeting of B-cell Lymphoma

The objective of this work was to develop rituximab (RTX)-modified polymeric micelles for targeting of B-cell lymphoma cells, through postinsertion of RTX-poly(ethylene glycol)-1,2-distearoyl-sn-glycero-3-phosphoethanolamine (RTX-PEG-DSPE) into methoxy poly(ethylene oxide)-poly(ε-caprolactone) (PEO-PCL) or methoxy poly(ethylene oxide)-poly(ε-benzylcarboxylate-ε-caprolactone) (PEO-PBCL) micelles. Mixed micelles were made traceable by introducing Cy5.5 to RTX and conjugating Cy3 to propargyl moiety, end-capped PCL or PBCL. Successful adaptation of the postinsertion method for the formation of immunomicelles was evidenced by measurement of RTX levels on the micellar surface, purified from free RTX by size exclusion chromatography, using microBSA assay. A change in the micellar diameter, from 50-70 nm for PEO-PCL and PEO-PBCL micelles and 20 nm for PEG-DSPE micelles, to 80-95 nm for the mixed micellar population as well as the critical micellar concentration of mixed micelles provided further proof for the success of the postinsertion method applied here. Mixed micelles containing PCL or PBCL with a degree of polymerization of 22 (PCL₂₂ and PBCL₂₂) were thermodynamically and kinetically more stable than those with PCL₁₅. Accordingly, RTX micelles containing PCL₂₂ or PBCL₂₂ showed a higher percentage of Cy³⁺/Cy^5.5+ cell population in CD20⁺ KG-15 cells, than those with PCL₁₅. The percentage of Cy³⁺/Cy^5.5+ cell population drastically reduced in the presence of competing RTX for micelles containing PCL₂₂ or PBCL₂₂ cores, indicating the superiority of these structures for active targeting of CD20⁺ cells. No significant difference in the cytotoxicity of paclitaxel in RTX-micelles versus plain ones was observed, reflecting the noninternalizing function of CD20. The results show that traceable mixed micelles prepared through postinsertion of RTX-PEG-DSPE to PEO-PCL₂₂ or PEO-PBCL₂₂ micelles can be used for targeting and/or imaging of CD20⁺ B cell lymphoma cells. The postinsertion method can be adopted to prepare other PEO-poly(ester)-based immunomicelles for active targeting of other diseased cells.

Nanotechnology platforms for cancer immunotherapy

Various cancer therapies have advanced remarkably over the past decade. Unlike the direct therapeutic targeting of tumor cells, cancer immunotherapy is a new strategy that boosts the host's immune system to detect specific cancer cells for efficient elimination. Nanoparticles incorporating immunomodulatory agents can activate immune cells and modulate the tumor microenvironment to enhance antitumor immunity. Such nanoparticle-based cancer immunotherapies have received considerable attention and have been extensively studied in recent years. This review thus focuses on nanoparticle-based platforms (especially naturally derived nanoparticles and synthetic nanoparticles) utilized in recent advances; summarizes delivery systems that incorporate various immune-modulating agents, including peptides and nucleic acids, immune checkpoint inhibitors, and other small immunostimulating agents; and introduces combinational cancer immunotherapy with nanoparticles, especially nanoparticle-based photo-immunotherapy and nanoparticle-based chemo-immunotherapy. Undoubtedly, the recent studies introduced in this review prove that nanoparticle-incorporated cancer immunotherapy is a highly promising treatment modality for patients with cancer. Nonetheless further research is needed to solve safety concerns and improve efficacy of nanoplatform-based cancer immunotherapy for future clinical application. This article is categorized under: Therapeutic Approaches and Drug Discovery > Nanomedicine for Oncologic Disease.

Sub-10 nm Theranostic Unimolecular Micelles with High Tumor-Specific Accumulation, Retention, and Inhibitory Effect

Theranostic agents that integrate far-red/near-infrared fluorescence and anticancer drugs are useful for biomedical applications such as imaging-guided therapy of cancers. However, the clinical translation of previously reported theranostic agents is still limited by factors such as weak fluorescence of the imaging probe, premature and off-target release of fluorophores and drugs during blood circulation, the long-term retention in the reticuloendothelial system, and side effects of toxicity. Here, we report a new type of ultrasmall theranostic unimolecular micelles with an average diameter below 10 nm, and dual functionalities of bright fluorescence in the spectral window of 600-800 nm toward noninvasive in vivo bioimaging and covalently bound anticancer drugs for specific cancer treatment. Each unimolecular micelle is formed by an amphiphilic bottlebrush copolymer containing a fluorescent conjugated backbone of poly(fluorene-alt-(4,7-bis(hexylthien)-2,1,3-benzothiadiazole)), from which hydrophobic disulfide-linked camptothecin as an anticancer drug and hydrophilic oligo(ethylene glycol) are grafted. These ultrasmall unimolecular micelles exhibit remarkably high efficiency of accumulation and retention in tumor tissues with a tumor inhibitory rate of 50%, but little distribution in other healthy organs and tissues. Such a feature of enhanced tumor targeting and reduced toxic side effects against healthy cells and tissues is promising for future clinical translation of imaging-guided cancer therapy.

Monocytes as Carriers of Magnetic Nanoparticles for Tracking Inflammation in the Epileptic Rat Brain

Background:

Inflammation is a hallmark of epileptogenic brain tissue. Previously, we have shown that inflammation in epilepsy can be delineated using systemically-injected fluorescent and magnetite- laden nanoparticles. Suggested mechanisms included distribution of free nanoparticles across a compromised blood-brain barrier or their transfer by monocytes that infiltrate the epileptic brain.

Objective:

In the current study, we evaluated monocytes as vehicles that deliver nanoparticles into the epileptic brain. We also assessed the effect of epilepsy on the systemic distribution of nanoparticleloaded monocytes.

Methods:

The in vitro uptake of 300-nm nanoparticles labeled with magnetite and BODIPY (for optical imaging) was evaluated using rat monocytes and fluorescence detection. For in vivo studies we used the rat lithium-pilocarpine model of temporal lobe epilepsy. In vivo nanoparticle distribution was evaluated using immunohistochemistry.

Results:

89% of nanoparticle loading into rat monocytes was accomplished within 8 hours, enabling overnight nanoparticle loading ex vivo. The dose-normalized distribution of nanoparticle-loaded monocytes into the hippocampal CA1 and dentate gyrus of rats with spontaneous seizures was 176-fold and 380-fold higher compared to the free nanoparticles (p<0.05). Seizures were associated with greater nanoparticle accumulation within the liver and the spleen (p<0.05).

Conclusion:

Nanoparticle-loaded monocytes are attracted to epileptogenic brain tissue and may be used for labeling or targeting it, while significantly reducing the systemic dose of potentially toxic compounds. The effect of seizures on monocyte biodistribution should be further explored to better understand the systemic effects of epilepsy.

Polymers and Polymer Nanocomposites for Cancer Therapy

Synthetic polymers, biopolymers, and their nanocomposites are being studied, and some of them are already used in different medical areas. Among the synthetic ones that can be mentioned are polyolefins, fluorinated polymers, polyesters, silicones, and others. Biopolymers such as polysaccharides (chitosan, hyaluronic acid, starch, cellulose, alginates) and proteins (silk, fibroin) have also become widely used and investigated for applications in medicine. Besides synthetic polymers and biopolymers, their nanocomposites, which are hybrids formed by a macromolecular matrix and a nanofiller (mineral or organic), have attracted great attention in the last decades in medicine and in other fields due to their outstanding properties. This review covers studies done recently using the polymers, biopolymers, nanocomposites, polymer micelles, nanomicelles, polymer hydrogels, nanogels, polymersomes, and liposomes used in medicine as drugs or drug carriers for cancer therapy and underlines their responses to internal and external stimuli able to make them more active and efficient. They are able to replace conventional cancer drug carriers, with better results.

Mussel-Derived, Cancer-Targeting Peptide as pH-Sensitive Prodrug Nanocarrier

In this work, we prepared a novel cancer chemotherapeutic nanocarrier through the self-assembly of a mussel-derived, cancer-targeting peptide with a pH-sensitive conjugation of antitumor drugs. The biomimetic peptide was designed with a fluorescent molecule fluorescein isothiocyanate for imaging, a RGD sequence for cancer-targeting and tetravalent catechol groups for dynamic conjugation of the antitumor drug bortezomib via pH-cleavable boronic acid-catechol esters. Our study demonstrated that the peptide-based prodrug nanocarrier dramatically the enhanced specific cellular uptake and cytotoxicity toward human breast cancer cells in vitro in comparison with free drug and nontargeting control nanoparticles. Likewise, the prodrug nanocarrier showed improved therapeutic efficacy and low systematic toxicity in vivo. Considering highly biomimetic nature of the peptide-based nanocarriers, rapid drug release from the dynamically conjugated prodrugs, and convenience of introducing cancer-targeting activity onto this nanosystem, we believe our work would provide new ideas for the development of intelligent and biocompatible drug delivery systems to improve the chemotherapy efficacy in clinic. Furthermore, the pH-sensitive drug conjugation mechanism on peptide-based nanocarriers would provide a hint for the exploitation of dynamic prodrug strategies and the development of highly biocompatible nanocarriers using biogenic materials, e.g., the proteinogenic nanomaterials decorated with drugs through dynamic covalent chemistry.