Synthesis of high drug loading, reactive oxygen species and esterase dual-responsive polymeric micelles for drug delivery

Fluorinated multifunctional polymer vesicles for enhanced ocular surface penetration and synergistic treatment of dry eye disease

Current pharmacotherapy for DED is limited by a vicious inflammatory cycle in which reactive oxygen species (ROS) play a critical role. Additionally, topical eye drop therapy for DED often suffers from poor ocular availability due to multiple ocular surface barriers. Considering the key role of the ROS-NLRP3-IL-1β signaling axis in DED, in this investigation, fluorinated multifunctional polymer vesicles were developed for enhanced ocular surface penetration and synergistic DED therapy by combining ROS scavenging and immunomodulation. MCC950, an NLRP3-IL-1β inhibitor, was loaded in situ during vesicle preparation. The results demonstrated that fluorocarbon units randomly distributed in the corona layer significantly enhanced ocular surface penetration. Furthermore, the vesicle membrane, composed of polyphenylborate ester blocks, efficiently scavenged excess ROS in inflamed corneal tissue. In response to excessive ROS, a hydrophobic-to-hydrophilic conversion of the vesicle membrane facilitated the efficient release of MCC950 to modulate the NLRP3-caspase-1-IL1β pathway. We believe that this work will provide insightful guidance to achieve effective treatment of DED by enhancing ocular surface penetration.

Synthesis of a Multifunctional Glyco-Block Copolymer through Reversible Addition-Fragmentation Chain Transfer Polymerization and Click Chemistry for Enzyme and Drug Loading into MDA-MB-231 Cells

Reversible addition-fragmentation chain transfer polymerization has been used in various applications such as preparing nanoparticles, stimulus-responsive polymers, and hydrogels. In this study, the combination of this polymerization method and Cu(I)-catalyzed azide-alkyne cycloaddition click chemistry was used to prepare the multifunctional glyco-diblock copolymer P(PEG-co-AM)-b-PF, which is composed of mannosides for cell targeting, poly(ethylene glycol) (PEG) for biocompatibility, and aryl-aldehyde moieties for enzyme immobilization. The alkyne group in the polymer structure enables the alternation for other azide-conjugated monomers. The stepwise synthesis of the polymers was fully characterized. P(PEG-co-AM)-b-PF was self-assembled into polymeric nanoparticles (BDOX-GOx@NPs) for glucose oxidase immobilization through Schiff base formation and for encapsulating the prodrug of arylboronate-linked doxorubicin (BA-DOX) under optimal conditions. Glucose oxidase in BDOX-GOx@NPs catalyzes glucose oxidation to produce gluconic acid and H2O2, which cause oxidative stress. Glucose oxidase also consumes glucose, causing starvation in cancer cells. The produced H2O2 can selectively activate the anticancer prodrug BA-DOX for chemotherapy. In vitro data indicate that GOx and the prodrug BA-DOX present inside BDOX-GOx@NPs exhibit higher stability than free glucose oxidase with a favorable active DOX release profile. MDA-MB-231 cells, which express mannose receptors, were used to establish a model in this study. The bioactivity of the nanoplatform in the two- and three-dimensional models of MDA-MB-231 cancer cells was investigated to ascertain its antitumor efficacy.

Research Status of Dendrimer Micelles in Tumor Therapy for Drug Delivery

Dendrimers are a family of polymers with highly branched structure, well-defined composition, and extensive functional groups, which have attracted great attention in biomedical applications. Micelles formed by dendrimers are ideal nanocarriers for delivering anticancer agents due to the explicit study of their characteristics of particle size, charge, and biological properties such as toxicity, blood circulation time, biodistribution, and cellular internalization. Here, the classification, preparation, and structure of dendrimer micelles are reviewed, and the specific functional groups modified on the surface of dendrimers for tumor active targeting, stimuli-responsive drug release, reduced toxicity, and prolonged blood circulation time are discussed. In addition, their applications are summarized as various platforms for biomedical applications related to cancer therapy including drug delivery, gene transfection, nano-contrast for imaging, and combined therapy. Other applications such as tissue engineering and biosensor are also involved. Finally, the possible challenges and perspectives of dendrimer micelles for their further applications are discussed.

Polymeric Micellar Systems-A Special Emphasis on "Smart" Drug Delivery

Concurrent developments in anticancer nanotechnological treatments have been observed as the burden of cancer increases every year. The 21st century has seen a transformation in the study of medicine thanks to the advancement in the field of material science and nanomedicine. Improved drug delivery systems with proven efficacy and fewer side effects have been made possible. Nanoformulations with varied functions are being created using lipids, polymers, and inorganic and peptide-based nanomedicines. Therefore, thorough knowledge of these intelligent nanomedicines is crucial for developing very promising drug delivery systems. Polymeric micelles are often simple to make and have high solubilization characteristics; as a result, they seem to be a promising alternative to other nanosystems. Even though recent studies have provided an overview of polymeric micelles, here we included a discussion on the "intelligent" drug delivery from these systems. We also summarized the state-of-the-art and the most recent developments of polymeric micellar systems with respect to cancer treatments. Additionally, we gave significant attention to the clinical translation potential of polymeric micellar systems in the treatment of various cancers.

Polymeric micelles and cancer therapy: an ingenious multimodal tumor-targeted drug delivery system

Since the beginning of pharmaceutical research, drug delivery methods have been an integral part of it. Polymeric micelles (PMs) have emerged as multifunctional nanoparticles in the current technological era of nanocarriers, and they have shown promise in a range of scientific fields. They can alter the release profile of integrated pharmacological substances and concentrate them in the target zone due to their improved permeability and retention, making them more suitable for poorly soluble medicines. With their ability to deliver poorly soluble chemotherapeutic drugs, PMs have garnered considerable interest in cancer. As a result of their remarkable biocompatibility, improved permeability, and minimal toxicity to healthy cells, while also their capacity to solubilize a wide range of drugs in their micellar core, PMs are expected to be a successful treatment option for cancer therapy in the future. Their nano-size enables them to accumulate in the tumor microenvironment (TME) via the enhanced permeability and retention (EPR) effect. In this review, our major aim is to focus primarily on the stellar applications of PMs in the field of cancer therapeutics along with its mechanism of action and its latest advancements in drug and gene delivery (DNA/siRNA) for cancer, using various therapeutic strategies such as crossing blood-brain barrier, gene therapy, photothermal therapy (PTT), and immunotherapy. Furthermore, PMs can be employed as "smart drug carriers," allowing them to target specific cancer sites using a variety of stimuli (endogenous and exogenous), which improve the specificity and efficacy of micelle-based targeted drug delivery. All the many types of stimulants, as well as how the complex of PM and various anticancer drugs react to it, and their pharmacodynamics are also reviewed here. In conclusion, commercializing engineered micelle nanoparticles (MNPs) for application in therapy and imaging can be considered as a potential approach to improve the therapeutic index of anticancer drugs. Furthermore, PM has stimulated intense interest in research and clinical practice, and in light of this, we have also highlighted a few PMs that have previously been approved for therapeutic use, while the majority are still being studied in clinical trials for various cancer therapies.

Boronates as hydrogen peroxide-reactive warheads in the design of detection probes, prodrugs, and nanomedicines used in tumors and other diseases

Hydrogen peroxide (H₂O₂) has always been a topic of great interests attributed to its vital role in biological process. H₂O₂ is known as a major reactive oxygen species (ROS) which is involve in numerous physiological processes such as cell proliferation, signal transduction, differentiation, and even pathogenesis. A plenty of diseases development such as chronic disease, inflammatory disease, and organ dysfunction are found to be relevant to abnormality of H₂O₂ production. Thus, imminent and feasible strategies to modulate and detect H₂O₂ level in vitro and in vivo have gained great importance. To date, the boronate-based chemical structure probes have been widely used to address the problems from the above aspects because of the rearranged chemical bonding which can detect and quantify ROS including hydrogen peroxide (H₂O₂) and peroxynitrite (ONOO^-). This present article discusses boronate-based probes based on the chemical structure difference as well as reactivities to H₂O₂ and ONOO^-. In this review, we also focus on the application of boronate-based probes in the field of cell imaging, prodrugs nanoplatform, nanomedicines, and electrochemical biosensors for disease diagnosis and treatment. In a nutshell, we outline the recent application of boronate-based probes and represent the prospective potentiality in biomedical domain in the future.

ROS-responsive copolymer micelles for inflammation triggered delivery of ibuprofen

Non-steroidal anti-inflammatory drugs (NSAIDs) are commonly used for the treatment of pain, inflammation and fever. However, most NSAIDs are poorly water soluble, making it difficult to be administered thus high doses are required to reach the intended therapeutic effect, resulting in associated side effects. In this study, ROS-responsive micellar systems based on a block copolymer consisting of methylpropyl thioether (MTPA) and N'N-dimethylacrylamide was developed and loaded with ibuprofen (IBU). Using lipopolysaccharide activated RAW 264.7 macrophage like cells, we demonstrated that IBU was released from the copolymer, specifically in the presence of ROS. Interestingly, IBU encapsulated in ROS-responsive nanoparticles exhibited greater anti-inflammatory potency compared to its free form. The work highlights the potential of the ROS-responsive micellar system developed in this work to be used as carrier of NSAIDs for the treatment of relevant inflammatory conditions.

Synthesis of Multi-Functional Nano-Vectors for Target-Specific Drug Delivery

Magnetic nanoparticles have gained attention in cancer therapy due to their non-toxic properties and high bio-compatibility. In this report, we synthesize a dual-responsive magnetic nanoparticle (MNP) that is sensitive to subtle pH and temperature change as in the tumor microenvironment. Thus, the functional doxorubicin (DOX)-loaded MNP (DOX-PNIPAM-PMAA@Fe3O4) can perform specific DOX releases in the cancer cell. The particle was characterized by scanning electron microscopy (SEM), dynamic light scattering (DLS), zeta-potential, Fourier-transform infrared spectroscopy (FTIR), and thermogravimetric analysis (TGA). The microscopy data revealed the particle as having a spherical shape. The zeta-potential and size distribution analysis data demonstrated the difference for the stepwise modified MNPs. The FTIR spectrum showed characteristic absorption bands of NH2-SiO2@Fe3O4, CPDB@Fe3O4, PMAA@Fe3O4, and PNIPAM-PMAA@Fe3O4. Drug-loading capacity and releasing efficiency were evaluated under different conditions. Through an in vitro analysis, we confirmed that PNIPAM-PMAA@Fe3O4 has enhanced drug releasing efficiency under acidic and warmer conditions. Finally, cellular uptake and cell viability were estimated via different treatments in an MDA-MB-231 cell line. Through the above analysis, we concluded that the DOX-loaded particles can be internalized by cancer cells, and such a result is positive and prospective.

Review of Contemporary Self-Assembled Systems for the Controlled Delivery of Therapeutics in Medicine

The novel and unique design of self-assembled micro and nanostructures can be tailored and controlled through the deep understanding of the self-assembly behavior of amphiphilic molecules. The most commonly known amphiphilic molecules are surfactants, phospholipids, and block copolymers. These molecules present a dual attraction in aqueous solutions that lead to the formation of structures like micelles, hydrogels, and liposomes. These structures can respond to external stimuli and can be further modified making them ideal for specific, targeted medical needs and localized drug delivery treatments. Biodegradability, biocompatibility, drug protection, drug bioavailability, and improved patient compliance are among the most important benefits of these self-assembled structures for drug delivery purposes. Furthermore, there are numerous FDA-approved biomaterials with self-assembling properties that can help shorten the approval pathway of efficient platforms, allowing them to reach the therapeutic market faster. This review focuses on providing a thorough description of the current use of self-assembled micelles, hydrogels, and vesicles (polymersomes/liposomes) for the extended and controlled release of therapeutics, with relevant medical applications. FDA-approved polymers, as well as clinically and commercially available nanoplatforms, are described throughout the paper.