Poly(Photosensitizer-Prodrug) Unimolecular Micelles for Chemo-Photodynamic Synergistic Therapy of Antitumor and Antibacteria

It is crucial to use simple methods to prepare stable polymeric micelles with multiple functions for cancer treatment. Herein, via a "bottom-up" strategy, we reported the fabrication of β-CD-(PEOSMA-PCPTMA-PPEGMA)21 (βPECP) unimolecular micelles that could simultaneously treat tumors and bacteria with chemotherapy and photodynamic therapy (PDT). The unimolecular micelles consisted of a 21-arm β-cyclodextrin (β-CD) core as a macromolecular initiator, photosensitizer eosin Y (EOS-Y) monomer EOSMA, anticancer drug camptothecin (CPT) monomer, and a hydrophilic shell PEGMA. Camptothecin monomer (CPTMA) could achieve controlled release of the CPT due to the presence of responsively broken disulfide bonds. PEGMA enhanced the biocompatibility of micelles as a hydrophilic shell. Two βPECP with different lengths were synthesized by modulating reaction conditions and the proportion of monomers, which both were self-assembled to unimolecular micelles in water. βPECP unimolecular micelles with higher EOS-Y/CPT content exhibited more excellent 1O2 production, in vitro drug release efficiency, higher cytotoxicity, and superior antibacterial activity. Also, we carried out simulations of the self-assembly and CPT release process of micelles, which agreed with the experiments. This nanosystem, which combines antimicrobial and antitumor functions, provides new ideas for bacteria-mediated tumor clinical chemoresistance.

Effect of zwitterionic sulfobetaine incorporation on blood behaviours, phagocytosis, and in vivo biodistribution of pH-responsive micelles with positive charges

pH-responsive micelles with positive charges are challenged by their significant effect on the cells/proteins and compromise their final fate due to electrostatic interactions. As one of the promising strategies, zwitterion incorporation in micelles has attracted considerable attention and displayed improved protein adsorption and blood circulation performances. However, previous reports in this field have been mostly limited in hemolysis for studying blood behaviour and lack a comprehensive understanding of their interactions with blood components. Herein, we present a prelimilary study on the effect of zwitterionic sulfobetaine incorporation on blood behaviour, phagocytosis, and in vivo biodistribution of pH-responsive micelles with positive charges. Amphiphilic triblock copolymers, namely poly(ε-caprolactone)-b-poly(N,N-diethylaminoethyl methacrylate)-(N-(3-sulfopropyl-N-methacryloxyethy-N,N-diethylammonium betaine)) (PCL-PDEAPSx, x = 2, 6, 10), containing different numbers of sulfobetaine groups were synthesized through four steps to prepare the pH-responsive micelles with positive charges. The effect of the sulfobetaine incorporation displayed different profiles, e.g., the micelles had no effect on RBC aggregation, thrombin time (TT), and platelet aggregation, while the cytotoxicity, hemolysis, RBC deformability, activated partial thromboplastin time (APTT), prothrombin time (PT), platelet activation, protein (albumin, fibrinogen, plasma) adsorption, phagocytosis, and in vivo biodistribution decreased with the increase in the sulfobetaine number, in which the transition mainly occurred at a sulfobetaine/tertiary amine group ratio of 3/7-1/1 compared to that of the mPEG control. In addition, the micelles displayed a strong inhibitory effect on the intrinsic coagulation pathway, which was associated with a significant decrease in the coagulation factor activity. Based on these findings, the related mechanism is discussed and proposed, which can aid the rational design of pH-responsive micelles for improved therapeutics.

Size-tunable nanogels for cascaded release of metronidazole and chemotherapeutic agents to combat Fusobacterium nucleatum-infected colorectal cancer

Bacteria play important roles in tumor formation, growth and metastasis through downregulating immune response and initiating drug resistance. Herein, size-tunable nanogels (NGs) have been developed to address the existing size paradox in tumor accumulation, intratumoral penetration and intracellular release of therapeutics for the treatment of Fusobacterium nucleatum (F. nucleatum)-infected colorectal cancer. Zinc-imidazolate frameworks with doxorubicin (DOX) loading and folate grafting (f-ZIFD) were mixed with metronidazole (MET) and encapsulated in NGs through thiol-ene click crosslinking of sulfhydryl hyaluronan, sulfhydryl alginate and 4-arm poly(ethylene glycol) acrylate. Hyaluronidase-initiated matrix degradation causes NG swelling to release sufficient MET and maintains a large size for an extended time period, and the gradually discharged f-ZIFD nanoparticles (NPs) from NGs exhibit acid-responsive intracellular release of DOX after folate-mediated internalization into tumor cells. The encapsulation into NGs significantly enhances the bioavailability and increases half-lives of MET and DOX by around 20 times. In the F. nucleatum-infected tumor model, the extended retention of swollen NGs and the efficient tumor infiltration and cellular uptake of the discharged f-ZIFD NPs cause 6 times higher DOX levels in tumors than that of free DOX administration. F. nucleatum promotes tumor cell proliferation and tumor growth, and the cascaded releases of MET and f-ZIFD NPs eliminate F. nucleatum to effectively inhibit tumor growth with a significant extension of animal survival. Thus, the hyaluronidase-mediated NG expansion and dual-responsive cascaded drug release have overcome challenges in the release regimen and size paradox of drug delivery carriers to combat bacteria-infected cancer.

pH/reduction dual-responsive hyaluronic acid-podophyllotoxin prodrug micelles for tumor targeted delivery

Polymer-based prodrug nanocarriers with tumor-targeting and controlled-release properties are in great demand for enhanced cancer treatment. Hyaluronic acid (HA), which has excellent biocompatibility and targeting ability for cluster determinant 44 (CD44), has been proposed for delivering drugs that have poor solubility and high toxicity. Herein, podophyllotoxin (PPT) was conjugated to HA via ester and disulfide linkages to construct a pH- and reduction-responsive prodrug (HA-S-S-PPT). The micelles self-assembled from HA-S-S-PPT prodrug efficiently accumulated at tumor site due to HA receptor-mediated endocytosis. HA-S-S-PPT micelles exhibited 33.1% higher cumulative release than HA-NH-CO-PPT micelles (sensitive only to pH) owing to their dual responsiveness to pH and reduction. HA-S-S-PPT micelles achieved excellent antitumor activity in vivo, with the tumor inhibition rate reaching 92%, significantly higher than that of HA-NH-CO-PPT micelles (65%), and negligible systemic toxicity. This controllable-targeting nanoparticle system provides a potential platform for clinical application of PPT.

Synthesis of self-assembled hyaluronan based nanoparticles and their applications in targeted imaging and therapy

Hyaluronan (HA) is a polysaccharide consisting of repeating disaccharides of N-acetyl-d-glucosamine and d-glucuronic acid. There are increasing interests in utilizing self-assembled HA nanoparticles (HA-NPs) for targeted imaging and therapy. The principal endogenous receptor of HA, cluster of differentiation 44 (CD44), is overexpressed on many types of tumor cells as well as inflammatory cells in human bodies. Active targeting from HA-CD44 mediated interaction and passive targeting due to the enhanced permeability retention (EPR) effect could lead to selective accumulation of HA-NPs at targeted disease sites. This review focuses on the synthesis strategies of self-assembled HA-NPs, as well as their applications in therapy and biomedical imaging.

Hyaluronic acid-based nanoplatforms for Doxorubicin: A review of stimuli-responsive carriers, co-delivery and resistance suppression

An important motivation for the use of nanomaterials and nanoarchitectures in cancer therapy emanates from the widespread emergence of drug resistance. Although doxorubicin (DOX) induces cell cycle arrest and DNA damage by suppressing topoisomerase activity, resistance to DOX has severely restricted its anti-cancer potential. Hyaluronic acid (HA) has been extensively utilized for synthesizing nanoparticles as it interacts with CD44 expressed on the surface of cancer cells. Cancer cells can take up HA-modified nanoparticles through receptor-mediated endocytosis. Various types of nanostructures such as carbon nanomaterials, lipid nanoparticles and polymeric nanocarriers have been modified with HA to enhance the delivery of DOX to cancer cells. Hyaluronic acid-based advanced materials provide a platform for the co-delivery of genes and drugs along with DOX to enhance the efficacy of anti-cancer therapy and overcome chemoresistance. In the present review, the potential methods and application of HA-modified nanostructures for DOX delivery in anti-cancer therapy are discussed.

Preparation and Antifouling Property of Polyurethane Film Modified by PHMG and HA Using Layer-by-Layer Assembly

To reduce the possibility of bacterial infection and implant-related complications, surface modification on polyurethane (PU) film is an ideal solution to endow hydrophobic PU with antibacterial and antifouling properties. In this work, a variety of polyhexamethylene guanidine/ hyaluronic acid (PHMG/HA) multilayer films were self-assembled layer-by-layer on PU films using polyanions, carboxyl-activated HA, and polycations PHMG by controlling the concentration of these polyelectrolytes as well as the number of layers self-assembled. Attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR) spectra, water contact angle (WCA), and A Atomic force microscope (AFM) of PU and modified PU films were studied. Protein adsorption and bacterial adhesion as well as the cytotoxicity against L929 of the film on selected PU-(PHMG/HA)₅/5-5 were estimated. The results showed that PU-(PHMG/HA)₅/5-5 had the best hydrophilicity among all the prepared films, possessing the lowest level of protein adsorption. Meanwhile, this film showed efficient broad-spectrum antibacterial performance as well as significant resistance of bacterial adhesion of more than a 99.9% drop for the selected bacteria. Moreover, almost no influence on cell viability of L929 enhanced the biocompatibility of film. Therefore, the modified PU films with admirable protein absorption resistance, antimicrobial performance, and biocompatibility would have promising applications in biomedical aspect.

Zoledronic Acid-Loaded Hybrid Hyaluronic Acid/Polyethylene Glycol/Nano-Hydroxyapatite Nanoparticle: Novel Fabrication and Safety Verification

Osteosarcoma is a malignant tumor that often occurs in adolescents and children. Zoledronic acid, a new-generation bisphosphonate, has been widely used as an antitumor drug to inhibit bone metastasis. However, the rapid renal elimination results in low effective concentrations. Meanwhile, high-dose intravenous zoledronic acid administration leads to severe side effects. The present study fabricated an organic-inorganic hybrid nanoparticle as the carrier of zoledronic acid. The rod-like nanoparticle, which had 150-nm length and 40-nm cross-sectional diameter, consisted of a hyaluronic acid/polyethylene glycol (HA-PEG) polymer shell and a nano-hydroxyapatite (nHA) core, with zoledronic acid molecules loading on the surface of nHA and clearance of HA-PEG shell. The nanoparticle was characterized by microscopic analysis, in vitro release study, cytotoxicity analysis, and in vivo immune response examination. Results showed that the compact and stable structure could achieve high drug loading efficiency, sustained drug release, and great biocompatibility. In vitro and in vivo experiments revealed the low cytotoxicity and acceptable immune response under low-dose nanoparticle treatment, indicating its potential application for future osteosarcoma therapeutic strategies.

Natural Ingredient-Based Polymeric Nanoparticles for Cancer Treatment

Cancer is a global health challenge. There are drawbacks to conventional chemotherapy such as poor bioavailability, development of drug resistance and severe side effects. Novel drug delivery system may be an alternative to optimize therapeutic effects. When such systems consist of natural materials, they offer important advantages: they are usually highly biocompatible, biodegradable, nontoxic and nonimmunogenic. Furthermore, natural materials can be easily modified for conjugation with a wide range of therapeutic agents and targeting ligands, according to the therapeutic purpose. This article reviews different natural ingredients and their applications in drug delivery systems for cancer therapy. Firstly, an overview of the polysaccharides and protein-based polymers that have been extensively investigated for drug delivery are described. Secondly, recent advances in using various natural ingredient-based polymeric nanoparticles for cancer therapy are reviewed. The characteristics of these delivery systems are summarized, followed by a discussion of future development and clinical potential. This review aims to summarize current knowledge and provide a basis for developing effective tailor-made formulations for cancer therapy in the future.

Extracellular Matrix Mimics Using Hyaluronan-Based Biomaterials

Hyaluronan (HA) is a critical element of the extracellular matrix (ECM). The regulated synthesis and degradation of HA modulates the ECM chemical and physical properties that, in turn, influence cellular behavior. HA triggers signaling pathways associated with the adhesion, proliferation, migration, and differentiation of cells, mediated by its interaction with specific cellular receptors or by tuning the mechanical properties of the ECM. This review summarizes the recent advances on strategies used to mimic the HA present in the ECM to study healthy or pathological cellular behavior. This includes the development of HA-based 2D and 3D in vitro tissue models for the seeding and encapsulation of cells, respectively, and HA particles as carriers for the targeted delivery of therapeutic agents.

Biomimetic phosphorylcholine strategy to improve the hemocompatibility of pH-responsive micelles containing tertiary amino groups

pH-responsive nanocarriers such as polymeric micelles that self-assemble from amphiphilic copolymers containing amino groups have been limited by their significant effects on the blood and thus compromise of their hemocompatibility due to the amino group-induced positive charges. Here we report a biomimetic phosphorylcholine strategy to improve the hemocompatibility of the pH-responsive micelles with positive charges. Amphiphilic copolymers containing different number of tertiary amino groups were synthesized in five steps through ring opening polymerization, azide reaction, thio-bromo "Click" chemistry, and atom transfer radical polymerization to self-assemble biomimetic phosphorylcholine micelles with pH-responsiveness, which shown no significant effects on red blood cells, coagulation, and platelet activation. Moreover, albumin adsorption on the micelles was significantly lower than that of polycaprolactone-methoxypolyethylene glycol (PCL-mPEG) control, and in terms of immune cells, the micelles showed controllable phagocytosis that dependent on the number of tertiary amino groups, in which the one containing four tertiary amino groups in its corresponding copolymer remains had a lower phagocytosis by whole blood leukocyte than that of PCL-mPEG. Based on these results, the hemocompatibility related mechanism of the micelles was discussed and proposed. Our findings demonstrated that this biomimetic phosphorylcholine is a promising strategy to improve the hemocompatibility of the positively charged nanocarriers.

Self-assembled hyaluronan nanocapsules for the intracellular delivery of anticancer drugs

Preparation of sophisticated delivery systems for nanomedicine applications generally involve multi-step procedures using organic solvents. In this study, we have developed a simple self-assembling process to prepare docetaxel-loaded hyaluronic acid (HA) nanocapsules by using a self-emulsification process without the need of organic solvents, heat or high shear forces. These nanocapsules, which comprise an oily core and a shell consisting of an assembly of surfactants and hydrophobically modified HA, have a mean size of 130 nm, a zeta potential of -20 mV, and exhibit high docetaxel encapsulation efficiency. The nanocapsules exhibited an adequate stability in plasma. Furthermore, in vitro studies performed using A549 lung cancer cells, showed effective intracellular delivery of docetaxel. On the other hand, blank nanocapsules showed very low cytotoxicity. Overall, these results highlight the potential of self-emulsifying HA nanocapsules for intracellular drug delivery.

A dual responsive hyaluronic acid graft poly(ionic liquid) block copolymer micelle for an efficient CD44-targeted antitumor drug delivery

Illustration of the formation and elevated antitumor mechanism of the HA-g-mPEG-polymers nanocarriers.