Integrated cell membrane encapsulated PQDs-TK quantum dot nanoclusters with ROS-responsive triggering for efficient and visualized DNA delivery

With the unique photo-physical properties and strong bio-compatibility. Quantum dots (QDs) have sparked interest in biomedical fields such as imaging, biosensing and therapeutics. However, the low stability and insufficient tumor specificity have largely constrained their potential biomedical applications. Here, we reported a cell membrane encapsulated PQDs-TK quantum dots nanoclusters (CM-PQDs-TK) gene delivery system with ROS-responsive triggering for efficient and visualized DNA delivery. CM-PQDs-TK possessed excellent DNA loading capacity and protective ability. The particle size and morphology change suggested that CM-PQDs-TK displayed superior ROS responsiveness. As expected, CM-PQDs-TK had an obvious nanocluster structure, and the particle size was stabilized in the range of 200-300 nm. Compared with PQDs and PQDs-TK, HlM-PQDs-TK/DNA encapsulated by Hela cell membrane has higher uptake efficiency and transfection ability, reaching 67.14 % and 63.41 % in 293 T cells, and the DNA transfection efficiency could still reach 43.98 % even in cancer cells (Hela cells). Moreover, flow cytometry and fluorescence microscopy showedthat nanoclusters could effectively enter tumor cells, and the internal DNA could be effectively released. In this process, PQDs-TK responded to high ROS in tumor cells and greatly improved DNA delivery efficiency. After loading DNA, cell membrane encapsulation technology was used to enhance its biocompatibility and targeting further. This work was anticipated to provide an in-depth understanding of the important role of PEI quantum dots in the field of ROS-responsive intelligent gene carriers and laid a foundation for the design and preparation of novel quantum dots gene carriers.

Cinnamaldehyde-Based ROS-Responsive Polymeric Gene Vectors for Efficient Gene Delivery and Tumor Cell Growth Inhibition

Reactive oxygen species (ROS)-sensitive polymers are extensively used in cancer therapies. However, the ROS levels in the tumor microenvironment are often insufficient to trigger an adequate therapeutic response. Herein, we report a cinnamaldehyde (CA)-based ROS-responsive cationic polymer (PCA) and demonstrate its high efficiency in gene delivery and tumor cell growth inhibition. CA could be released from the polymer via a ROS-sensitive thioacetal bond by endogenous ROS. The released CA successively induced more ROS accumulation through GSH depletion, and the positive feedback helped PCA to achieve self-accelerating degradation. Results proved that PCA/p53 complexes were efficient in depleting GSH, upregulating ROS levels, and gene transfection. Besides, PCA was also shown to be effective in delivering the therapeutic gene p53. More importantly, PCA/p53 complexes could significantly induce tumor cell growth suppression by a synergistic effect of PCA and p53, providing valuable insights into the design of self-amplifying ROS-responsive polymeric gene vectors.

Tumor Microenvironment-Responsive Polymer-Based RNA Delivery Systems for Cancer Treatment

Ribonucleic acid (RNA) therapeutics offer a broad prospect in cancer treatment. However, their successful application requires overcoming various physiological barriers to effectively deliver RNAs to the target sites. Currently, a number of RNA delivery systems based on polymeric nanoparticles are developed to overcome these barriers in RNA delivery. This work provides an overview of the existing RNA therapeutics for cancer gene therapy, and particularly summarizes those that are entering the clinical phase. This work then discusses the core features and latest research developments of tumor microenvironment-responsive polymer-based RNA delivery carriers which are designed based on the pathological characteristics of the tumor microenvironment. Finally, this work also proposes opportunities for the transformation of RNA therapies into cancer immunotherapy methods in clinical applications.

Reactive oxygen species driven prodrug-based nanoscale carriers for transformative therapies

Reactive oxygen species (ROS) drive processes in various pathological conditions serving as an attractive target for therapeutic strategies. This review highlights the development and use of ROS-dependent prodrug-based nanoscale carriers that has transformed many biomedical applications. Incorporating prodrugs into nanoscale carriers not only improves their stability and solubility but also enables site-specific drug delivery ultimately enhancing the therapeutic effectiveness of the nanoscale carriers. We critically examine recent advances in ROS-responsive nanoparticulate platforms, encompassing liposomes, polymeric nanoparticles, and inorganic nanocarriers. These platforms facilitate precise control over drug release upon encountering elevated ROS levels at disease sites, thereby minimizing off-target effects and maximizing therapeutic efficiency. Furthermore, we investigate the potential of combination therapies in which ROS-activated prodrugs are combined with other therapeutic agents and underscore their synergistic potential for treating multifaceted diseases. This comprehensive review highlights the immense potential of ROS-dependent prodrug-based nanoparticulate systems in revolutionizing biomedical applications; such nanoparticulate systems can facilitate selective and controlled drug delivery, reduce toxicity, and improve therapeutic outcomes for ROS-associated diseases.

Microenvironment-responsive smart hydrogels with antibacterial activity and immune regulation for accelerating chronic wound healing

Current therapeutic strategies for chronic refractory wounds remain challenge owing to their unfavorable wound microenvironment and poor skin regeneration ability. Thus far, a regimen for effective chronic refractory wounds management involves bacterial elimination, alleviation of oxidative stress, inhibition of inflammatory response, and promotion of angiogenesis. In this work, an injectable glycopeptide hydrogel based on phenylboronic acid-grafted ϵ-polylysine (EPBA) and poly (vinyl alcohol) (PVA) with pH/reactive oxygen species (ROS) dual-responsive properties was prepared, which exerted intrinsic antibacterial and antioxidant properties. ROS-responsive micelles (MIC) loaded with herb-derived Astragaloside IV (AST) are introduced into the hydrogel before gelation. Attributed to the acidic condition and oxidative stress microenvironment of wound bed, the hydrogel gradually disintegrates, and the released EPBA could help to eliminate bacterial. Meanwhile, the subsequential release of AST could help to achieve anti-oxidation, anti-inflammatory, proangiogenic effects, and regulation of macrophage polarization to accelerate chronic wound healing. In addition, the wound repair mechanism of composite hydrogel accelerating skin regeneration was assessed by RNA-sequencing, exploring a range of potential targets and pathway for further study. Collectively, this multifunctional hydrogel dressing, matching different healing stages of tissue remodeling, holds a great potential for the treatment of chronic refractory wounds.

Free drug and ROS-responsive nanoparticle delivery of synergistic doxorubicin and olaparib combinations to triple negative breast cancer models

Combinations of the topoisomerase II inhibitor doxorubicin and the poly (ADP-ribose) polymerase inhibitor olaparib offer potential drug-drug synergy for the treatment of triple negative breast cancers (TNBC). In this study we performed in vitro screening of combinations of these drugs, administered directly or encapsulated within polymer nanoparticles, in both 2D and in 3D spheroid models of breast cancer. A variety of assays were used to evaluate drug potency, and calculations of combination index (CI) values indicated that synergistic effects of drug combinations occurred in a molar-ratio dependent manner. It is suggested that the mechanisms of synergy were related to enhancement of DNA damage as shown by the level of double-strand DNA breaks, and mechanisms of antagonism associated with mitochondrial mediated cell survival, as indicated by reactive oxygen species (ROS) generation. Enhanced drug delivery and potency was observed with nanoparticle formulations, with a greater extent of doxorubicin localised to cell nuclei as evidenced by microscopy, and higher cytotoxicity at the same time points compared to free drugs. Together, the work presented identifies specific combinations of doxorubicin and olaparib which were most effective in a panel of TNBC cell lines, explores the mechanisms by which these combined agents might act, and shows that formulation of these drug combinations into polymeric nanoparticles at specific ratios conserves synergistic action and enhanced potency in vitro compared to the free drugs.

Theranostic Fluorescent Probes

The ability to gain spatiotemporal information, and in some cases achieve spatiotemporal control, in the context of drug delivery makes theranostic fluorescent probes an attractive and intensely investigated research topic. This interest is reflected in the steep rise in publications on the topic that have appeared over the past decade. Theranostic fluorescent probes, in their various incarnations, generally comprise a fluorophore linked to a masked drug, in which the drug is released as the result of certain stimuli, with both intrinsic and extrinsic stimuli being reported. This release is then signaled by the emergence of a fluorescent signal. Importantly, the use of appropriate fluorophores has enabled not only this emerging fluorescence as a spatiotemporal marker for drug delivery but also has provided modalities useful in photodynamic, photothermal, and sonodynamic therapeutic applications. In this review we highlight recent work on theranostic fluorescent probes with a particular focus on probes that are activated in tumor microenvironments. We also summarize efforts to develop probes for other applications, such as neurodegenerative diseases and antibacterials. This review celebrates the diversity of designs reported to date, from discrete small-molecule systems to nanomaterials. Our aim is to provide insights into the potential clinical impact of this still-emerging research direction.

PEI-based functional materials: Fabrication techniques, properties, and biomedical applications

Cationic polymers have recently attracted considerable interest as research breakthroughs for various industrial and biomedical applications. They are particularly interesting due to their highly positive charges, acceptable physicochemical properties, and ability to undergo further modifications, making them attractive candidates for biomedical applications. Polyethyleneimines (PEIs), as the most extensively utilized polymers, are one of the valuable and prominent classes of polycations. Owing to their flexible polymeric chains, broad molecular weight (MW) distribution, and repetitive structural units, their customization for functional composites is more feasible. The specific beneficial attributes of PEIs could be introduced by purposeful functionalization or modification, long service life, biocompatibility, and distinct geometry. Therefore, PEIs have significant potential in biotechnology, medicine, and bioscience. In this review, we present the advances in PEI-based nanomaterials, their transfection efficiency, and their toxicity over the past few years. Furthermore, the potential and suitability of PEIs for various applications are highlighted and discussed in detail. This review aims to inspire readers to investigate innovative approaches for the design and development of next-generation PEI-based nanomaterials possessing cutting-edge functionalities and appealing characteristics.

Biodegradable nanomaterials for diagnosis and therapy of tumors

Although degradable nanomaterials have been widely designed and applied for cancer bioimaging and various cancer treatments, few reviews of biodegradable nanomaterials have been reported. Herein, we have summarized the representative research advances of biodegradable nanomaterials with respect to the mechanism of degradation and their application in tumor imaging and therapy. First, four kinds of tumor microenvironment (TME) responsive degradation are presented, including pH, glutathione (GSH), hypoxia and matrix metalloproteinase (MMP) responsive degradation. Second, external stimulation degradation is summarized briefly. Next, we have outlined the applications of nanomaterials in bioimaging. Finally, we have focused on some typical examples of biodegradable nanomaterials in radiotherapy (RT), photothermal therapy (PTT), starvation therapy, photodynamic therapy (PDT), chemotherapy, chemodynamic therapy (CDT), sonodynamic therapy (SDT), gene therapy, immunotherapy and combination therapy.

Cartilage targeting therapy with reactive oxygen species-responsive nanocarrier for osteoarthritis

Targeting cartilage is a promising strategy for the treatment of osteoarthritis, and various delivery vehicles were developed to assist the therapeutic agents into cartilage. However, the underlying biomechanisms and potential bioactivities remain oversimplified. Inspired by oxidative stress in the pathogenesis of osteoarthritis, we firstly testified the antioxidant capacity of a synthetic small molecule compound, oltipraz (OL), to the chondrocytes treated by IL-1β. Then a functional reactive oxygen species (ROS) responsive nanocarrier, mesoporous silica nanoparticles (MSN) modified with methoxy polyethylene glycol-thioketal, was constructed. In vitro biomolecular results showed that compared with OL alone, MSN-OL could significantly activate Nrf2/HO-1 signaling pathway, which exhibited better ROS-scavenging proficiency and greater anti-apoptotic ability to protect mitochondrial membrane potential of chondrocytes. Further bioinformatics analysis revealed that MSN-OL suppressed clusters of genes associated with extracellular matrix organization, cell apoptosis and cellular response to oxidative stress. Animal experiments further confirmed the great cartilage-protecting ability of MSN-OL through upregulating the expression of Nrf2/HO-1 signaling pathway without obvious toxicity. In summary, this study provided a delivery system through ROS-responsive regulation of the therapeutic agents into chondrocytes of the cartilage, and confirmed the exact biological mechanisms of this innovative strategy.

Applications of the ROS-Responsive Thioketal Linker for the Production of Smart Nanomedicines

Reactive oxygen species (ROS)-sensitive drug delivery systems (DDS) specifically responding to altered levels of ROS in the pathological microenvironment have emerged as an effective means to enhance the pharmaceutical efficacy of conventional nanomedicines, while simultaneously reducing side effects. In particular, the use of the biocompatible, biodegradable, and non-toxic ROS-responsive thioketal (TK) functional group in the design of smart DDS has grown exponentially in recent years. In the design of TK-based DDS, different technological uses of TK have been proposed to overcome the major limitations of conventional DDS counterparts including uncontrolled drug release and off-target effects. This review will focus on the different technological uses of TK-based biomaterials in smart nanomedicines by using it as a linker to connect a drug on the surface of nanoparticles, form prodrugs, as a core component of the DDS to directly control its structure, to control the opening of drug-releasing gates or to change the conformation of the nano-systems. A comprehensive view of the various uses of TK may allow researchers to exploit this reactive linker more consciously while designing nanomedicines to be more effective with improved disease-targeting ability, providing novel therapeutic opportunities in the treatment of many diseases.

Targeted Delivery Methods for Anticancer Drugs

Several drug-delivery systems have been reported on and often successfully applied in cancer therapy. Cell-targeted delivery can reduce the overall toxicity of cytotoxic drugs and increase their effectiveness and selectivity. Besides traditional liposomal and micellar formulations, various nanocarrier systems have recently become the focus of developmental interest. This review discusses the preparation and targeting techniques as well as the properties of several liposome-, micelle-, solid-lipid nanoparticle-, dendrimer-, gold-, and magnetic-nanoparticle-based delivery systems. Approaches for targeted drug delivery and systems for drug release under a range of stimuli are also discussed.

Cationic Polyporphyrins as siRNA Delivery Vectors for Photodynamic and Gene Synergistic Anticancer Therapy

Successful gene therapy is highly dependent on the efficiency of gene delivery, which is mostly achieved by the carrier. Current gene carriers are generally nontherapeutic and take over most of the proportion in the delivery systems. Therefore, a library of polymerized and cationic photosensitive drugs (polyphotosensitizers, pPSs) with HIF-1α siRNA delivery capability is constructed to realize using "drug" to deliver "gene". The pPS component acts as both a therapeutic carrier for intracellular HIF-1α siRNA delivery and a photosensitive drug with photodynamic therapy (PDT). A reactive oxygen species (ROS)-cleavable linker is used to polymerize PS, allowing the successful segregation of PS monomers in space, avoiding the undesired aggregation-caused quenching (ACQ) effect and enhancing the in vitro and in vivo PDT effect. The complexes formed by pPSs and HIF-1α siRNA exhibited desired siRNA condensation and serum stability at the optimal conditions (pPSs with guanidines/siRNA weight ratio of 15), efficient intracellular internalization, and gene-silencing efficiency (60%) compared with commercial available transfection reagents (40%), as well as synergistic in vitro and in vivo phototoxicity for the combination PDT-gene therapy toward cancer treatment. This study provides a promising paradigm for the design of both the gene delivery carrier and the photosensitizer, as well as for broad utilities in the combination therapy toward cancer treatment.

Properties of polyplexes formed between a cationic polymer derived from l-arabinitol and nucleic acids

Polyplexes formed between a cationic polymer, PUArab, and both linear and plasmid DNA were studied. The transfection efficiency of PURarab/pDNA was investigated.

Multicomponent polymerization toward biodegradable polymers with diverse responsiveness in tumor microenvironments

Multicomponent polymerization (MCP), as a powerful synthetic tool, has been widely utilized to prepare diverse functional polymers for optical, electronic, and biomedical applications.