Surface-anchored tumor microenvironment-responsive protein nanogel-platelet system for cytosolic delivery of therapeutic protein in the post-surgical cancer treatment

Tumor-targeting and redox-responsive photo-cross-linked nanogel derived from multifunctional hyaluronic acid-lipoic acid conjugates for enhanced in vivo protein delivery

The fabrication of a secure and efficacious nanosystem for intracellular protein delivery is greatly desired, which relies on coordination of the interactions among loading ability, systemic stability, precise tumor targeting, successful endo-lysosomal evasion, and on-demand release characteristics. Herein, we constructed tumor-targeting and redox-responsive photo-crosslinkable nanogels (TRNGs) via UV light-induced ring-opening polymerization (ROP) of lipoic acid moieties incorporated in the side chain of methoxy poly (ethylene glycol) and diethylenetriamine-modified hyaluronic acid (HA-g-mPEG/Deta-c-LA) to create disulfide cross-linked core for the in vivo delivery of cytochrome c (CC). The TRNGs had satisfactory stability for 48 h in physiological environments and high CC encapsulation efficiency via multi-physical interactions. In vivo and in vitro fluorescence imaging proved the preferential accumulation of CC-loaded TRNGs in tumor tissues of human lung tumor-bearing mice and these nanoparticles were efficiently taken up into the CD44-positive A549 cells through CD44-mediated endocytosis compared to CD44-negative HepG2 cells. In addition, the nanoparticles underwent swift exocytosis from the endo-lysosomal compartment, thus promoting the liberation of CC within a reducing intracellular environment. The in vitro therapeutic outcomes proved that empty TRNGs presented excellent biocompatibility and minimal cytotoxicity, whereas CC-loaded TRNGs demonstrated a superior capacity to kill A549 cells compared to free CC and exhibited low effect on CD44-negative HepG2 cells. Moreover, CC-loaded TRNGs also had enhanced antitumor activity without eliciting any adverse effects. Our study highlighted the potential of TRNGs as a novel nanoplatform for the treatment of protein-based cancers.

Long-acting bioengineered platelets with internal doxorubicin loaded and external quercetin liposomes anchored for post-surgical tumor therapy

Due to its natural tumor targeting ability, platelet-based drug delivery platform shows the great potential for tumor targeted treatment. However, both limited in vitro storage stability and rapid in vivo clearance rate severely restrict its clinical application. Here, utilizing the spatial structure of platelets precisely, chemotherapy drug doxorubicin (Dox) and liposomes-containing quercetin (Que) are loaded inside and anchored outside platelets, respectively, for establishing the engineered platelet platform (PDQLs). Dox plays the important role in inhibiting tumor growth, while Que mainly inhibits platelet apoptosis through activating serine/threonine protein kinase. PDQLs show the strong ability to resist external stimulation and physical damage. After being stored at room temperature for 4 days, more than 70 % of the platelets remain active. Given the natural wound tropism and tumor targeting abilities, the tumor accumulation of PDQLs is 1.02-fold higher than that of the solution. Base on the stealth characteristics of platelets and the continuous action of Que, PDQLs exhibit 10.63-fold increase area under the curve of solution. PDQLs can balance the anti-tumor recurrence and metastasis efficacy after surgery and safety. Our findings open a promising perspective and new sights for the development of bioengineered platelet platform in clinical application.

Targeting capture and eradicate circulating tumor cells by activated platelet derived vehicle for inhibiting triple-negative breast cancer metastasis

Circulating tumor cells (CTCs) are cardinal intermediaries in the metastatic cascade, particularly in triple-negative breast cancer (TNBC), owing to their high-affinity interactions that bolster survival and dissemination. Addressing this pivotal mechanism, we have developed APEVs@DOX, a pioneering biomimetic delivery system. Utilizing activated platelet membranes as a scaffold, APEVs@DOX recapitulates the natural affinity between platelets and CTCs, enabling targeted delivery of doxorubicin. Our results, substantiated by meticulous in vitro and in vivo experimentation, revealed 78 % reduction in lung metastasis nodules in murine models relative to controls, affirming APEVs@DOX's proficiency in CTCs capture and eradication. This study not only illuminates the potential of CTCs-targeted therapies in the precision medicine armamentarium for TNBC but also contributes empirical data to guide the strategic design of anti-metastatic interventions. The therapeutic impact of APEVs@DOX in curtailing metastatic spread offers a beacon of hope for advancing TNBC treatment paradigms.

Microwave-Responsive Engineered Platelet Microneedle Patch for Deep Tumor Penetration and Precision Therapy

Controllable and precise delivery of therapeutic agents is critical for effective tumor therapy. However, tumor targeting and the deep penetration of drugs remain among the most challenging issues in achieving controlled delivery. Herein, a novel engineered platelet microneedle patch with a microwave-responsive magnetic biometal-organic framework is proposed to facilitate the combination of the engineered platelet and microwave hyperthermia, enhancing deep drug penetration into tumors and enabling precision therapy. The prepared magnetic biometal-organic framework as nanomedicine exhibits excellent microwave thermal effects. The engineered platelets could be activated in the tumor microenvironment to release PMPs and nanomedicines combined with microwave hyperthermia for enhancing both cell uptake and deep drug penetration into tumors. The developed separable microneedle patch system allows the microneedle tip to be quickly detached from the backing layer and retained within the target tissue for repeated local cancer hyperthermia treatments. By integration of engineered platelets into the microneedle patch, the transdermal deep delivery of drugs could be effectively enhanced for local microwave thermochemotherapy of tumors. This work represents the first attempt to graft microwave-responsive inorganic nanomedicines onto platelets as cell drugs, offering a novel strategy for precise drug delivery activated by microwave thermal therapy.

A facile combined therapy of chemotherapeutic agent and microRNA for hepatocellular carcinoma using non-cationic nanogel

High drug resistance remains a challenge for chemotherapy against hepatocellular carcinoma (HCC). Combining chemotherapeutic agents with microRNA (miRNA), which simultaneously regulates multiple pathways, offers a promising approach to improve therapeutic efficacy against HCC. Although cationic amphiphilic copolymers have been used to co-deliver these agents, their effectiveness is often limited by low co-encapsulation efficiency and inherent cationic toxicity. In this study, we developed a facile approach to co-deliver doxorubicin (DOX) and miRNA-26a (miR-26a) using a non-cationic nanogel. The incorporation of an amphiphilic monomer and a lysosomal enzyme-sensitive crosslinker endows the nanomedicine with several advantages, including high co-encapsulation efficiency, lysosomal escape, and minimal toxicity. miR-26a significantly increased the sensitivity of HCC to DOX by 3.35-fold through targeting multiple pathways, and promoted DOX penetration within tumor tissue through reducing type I collagen content, thereby showing significant synergistic anticancer effects. This study provides a facile and biosafe nanoplatform for the efficient co-delivery of DOX and miRNA with synergistic drug effect.

Natural endogenous material-based vehicles for delivery of macromolecular drugs

Natural endogenous materials (NEMs), such as cell and cell derivatives, polysaccharide, protein and peptide, and nucleic acid-derived vectors, often exhibit biocompatibility, biodegradability and natural homing ability, which can minimize adverse reactions in vivo and have the potential to improve drug delivery efficacy. Currently, a variety of drug delivery systems (DDSs) based on NEMs have been constructed for macromolecules to address the challenges posed by their inherent large size, intricate structure, low permeability, and susceptibility to harsh environments. The aim of this article is to provide a comprehensive overview of various delivery strategies that predominantly utilize NEMs as carriers for macromolecular delivery. By thoroughly discussing the pros and cons of NEM-based DDSs, we hope to provide valuable insights into future innovations in pharmaceutical science, with a focus on improving therapeutic outcomes through advanced drug formulations.

Multi-Sensitive Au NCs/5-FU@Carr-LA Composite Hydrogels for Targeted Multimodal Anti-Tumor Therapy

Multifunctional targeted drug delivery systems have been explored as a novel cancer treatment strategy to overcome limitations of traditional chemotherapy. The combination of photodynamic therapy and chemotherapy has been shown to enhance efficacy, but the phototoxicity of traditional photosensitizers is a challenge. In this study, we prepared a multi-sensitive composite hydrogel containing gold nanoclusters (Au NCs) and the temperature-sensitive antitumor drug 5-fluorourac il (5-FU) using carboxymethyl cellulose (Carr) as a dual-functional template. Au NCs were synthesized using sodium borohydride as a reducing agent and potassium as a promoter. The resulting Au NCs were embedded in the Carr hydrogel, which was then conjugated with lactobionic acid (LA) as a targeting ligand. The resulting Au NCs/5-FU@Carr-LA composite hydrogel was used for synergistic photodynamic therapy (PDT), photothermal therapy (PTT), and chemotherapy. Au NCs/5-FU@Carr-LA releases the drug faster at pH 5.0 due to the acid sensitivity of the Carr polymer chain. In addition, at 50 °C, the release rate of Au NCs/5-FU@Carr-LA is 78.2%, indicating that the higher temperature generated by the photothermal effect is conducive to the degradation of Carr polymer chains. The Carr hydrogel stabilized the Au NCs and acted as a matrix for drug loading, and the LA ligand facilitated targeted delivery to tumor cells. The composite hydrogel exhibited excellent biocompatibility and synergistic antitumor efficacy, as demonstrated by in vitro and in vivo experiments. In addition, the hydrogel had thermal imaging capabilities, making it a promising multifunctional platform for targeted cancer therapy.

Emerging platelet-based drug delivery systems

Drug delivery systems are becoming increasingly utilized; however, a major challenge in this field is the insufficient target of tissues or cells. Although efforts with engineered nanoparticles have shown some success, issues with targeting, toxicity and immunogenicity persist. Conversely, living cells can be used as drug-delivery vehicles because they typically have innate targeting mechanisms and minimal adverse effects. As active participants in hemostasis, inflammation, and tumors, platelets have shown great potential in drug delivery. This review highlights platelet-based drug delivery systems, including platelet membrane engineering, platelet membrane coating, platelet cytoplasmic drug loading, genetic engineering, and synthetic/artificial platelets for different applications.

Platelet-Based Nanoparticles with Stimuli-Responsive for Anti-Tumor Therapy

In addition to hemostasis and coagulation, years of studies have proved that platelets are involved in the whole process of tumor progression, including tumor invasion, intravasation, extravasation, and so on. It means that this property of platelets can be used in anti-tumor therapy. However, traditional platelet-based antitumor drugs often cause autologous platelet damage due to lack of targeting, resulting in serious side effects. Therefore, the researchers designed a variety of anti-tumor drug delivery systems based on platelets by targeting platelets or platelet membrane coating. The drug delivery systems have special response modes, which is crucial in the design of nanoparticles. These modes enhance the targeting and improve the anti-tumor effect. Here, we present a review of recent discoveries in the field of the crosstalk between platelets and tumors and the progress of platelet-based anti-tumor nanoparticles.

Revolutionizing cancer treatment: The power of cell-based drug delivery systems

Intravenous administration of drugs is a widely used cancer therapy approach. However, the efficacy of these drugs is often hindered by various biological barriers, including circulation, accumulation, and penetration, resulting in poor delivery to solid tumors. Recently, cell-based drug delivery platforms have emerged as promising solutions to overcome these limitations. These platforms offer several advantages, including prolonged circulation time, active targeting, controlled release, and excellent biocompatibility. Cell-based delivery systems encompass cell membrane coating, intracellular loading, and extracellular backpacking. These innovative platforms hold the potential to revolutionize cancer diagnosis, monitoring, and treatment, presenting a plethora of opportunities for the advancement and integration of pharmaceuticals, medicine, and materials science. Nevertheless, several technological, ethical, and financial barriers must be addressed to facilitate the translation of these platforms into clinical practice. In this review, we explore the emerging strategies to overcome these challenges, focusing specifically on the functions and advantages of cell-mediated drug delivery in cancer treatment.

Platelets for advanced drug delivery in cancer

INTRODUCTION

Cancer-related drug expenses are rising with the increasing cancer incidence and cost may represent a severe challenge for drug access for patients with cancer. Consequently, strategies for increasing therapeutic efficacy of already available drugs may be essential for the future health-care system.

AREAS COVERED

In this review, we have investigated the potential for the use of platelets as drug-delivery systems. We searched PubMed and Google Scholar to identify relevant papers written in English and published up to January 2023. Papers were included at the authors' discretion to reflect an overview of state of the art.

EXPERT OPINION

It is known that cancer cells interact with platelets to gain functional advantages including immune evasion and metastasis development. This platelet-cancer interaction has been the inspiration for numerous platelet-based drug delivery systems using either drug-loaded or drug-bound platelets, or platelet membrane-containing hybrid vesicles combining platelet membranes with synthetic nanocarriers. Compared to treatment with free drug or synthetic drug vectors, these strategies may improve pharmacokinetics and selective cancer cell targeting. There are multiple studies showing improved therapeutic efficacy using animal models, however, no platelet-based drug delivery systems have been tested in humans, meaning the clinical relevance of this technology remains uncertain.