Lysosome-Independent Intracellular Drug/Gene Codelivery by Lipoprotein-Derived Nanovector for Synergistic Apoptosis-Inducing Cancer-Targeted Therapy

Codelivery of Doxorubicin and p53 Gene by β-Cyclodextrin-Based Supramolecular Nanoparticles Formed via Host-Guest Complexation and Electrostatic Interaction

We developed a supramolecular system for codelivery of doxorubicin (Dox) and p53 gene based on a β-CD-containing star-shaped cationic polymer. First, a star-shaped cationic polymer consisting of a β-CD core and 3 arms of oligoethylenimine (OEI), named CD-OEI, was used to form a supramolecular inclusion complex with hydrophobic Dox. The CD-OEI/Dox complex was subsequently used to condense plasmid DNA via electrostatic interactions to form CD-OEI/Dox/DNA polyplex nanoparticles with positive surface charges that enhanced the cellular uptake of both Dox and DNA. This supramolecular drug and gene codelivery system showed high gene transfection efficiency and effective protein expression in cancer cells. The codelivery of Dox and DNA encoding the p53 gene resulted in reduced cell viability and enhanced antitumor effects at low Dox concentrations. With its enhanced cellular uptake and anticancer efficacy, the system holds promise as a delivery carrier for potential combination cancer therapies.

Well-Defined pH-Responsive Self-Assembled Block Copolymers for the Effective Codelivery of Doxorubicin and Antisense Oligonucleotide to Breast Cancer Cells

The worldwide steady increase in the number of cancer patients motivates the development of innovative drug delivery systems for combination therapy as an effective clinical modality for cancer treatment. Here, we explored a design concept based on poly(ethylene glycol)-b-poly(2-(dimethylamino)ethyl methacrylate)-b-poly(2-hydroxyethyl methacrylate-formylbenzoic acid) [PEG-b-PDMAEMA-b-P(HEMA-FBA)] for the dual delivery of doxorubicin (DOX) and GTI2040 (an antisense oligonucleotide for ribonucleotide reductase inhibition) to MCF-7 breast cancer cells. PEG-b-PDMAEMA-b-PHEMA, the precursor copolymer, was prepared through chain extensions from a PEG-based macroinitiator via two consecutive atom transfer radical polymerization (ATRP) steps. Then, it was modified at the PHEMA block with 4-formylbenzoic acid (FBA) to install reactive aldehyde moieties. A pH-responsive polymer-drug conjugate (PDC) was obtained by conjugating DOX to the polymer structure via acid-labile imine linkages, and subsequently self-assembled in an aqueous solution to form DOX-loaded self-assembled nanoparticles (DOX-SAN) with a positively charged shell. DOX-SAN condensed readily with negatively charged GTI2040 to form GTI2040/DOX-SAN nanocomplexes. Gel-retardation assay confirmed the affinity between GTI2040 and DOX-SAN. The GTI2040/DOX-SAN nanocomplex at N/P ratio of 30 exhibited a volume-average hydrodynamic size of 136.4 nm and a zeta potential of 21.0 mV. The pH-sensitivity of DOX-SAN was confirmed by the DOX release study based on the significant cumulative DOX release at pH 5.5 relative to pH 7.4. Cellular uptake study demonstrated favorable accumulation of GTI2040/DOX-SAN inside MCF-7 cells compared with free GTI2040/DOX. In vitro cytotoxicity study indicated higher therapeutic efficacy of GTI2040/DOX-SAN relative to DOX-SAN alone because of the downregulation of the R2 protein of ribonucleotide reductase. These outcomes suggest that the self-assembled pH-responsive triblock copolymer is a promising platform for combination therapy, which may be more effective in combating cancer than individual therapies.

An enzyme-responsive and NIR-triggered lipid-polymer hybrid nanoplatform for synergistic photothermal/chemo cancer therapy

A combination of photothermal therapy (PTT) and chemotherapy is an emerging therapeutic strategy with promising clinical prospects in cancer treatment. Despite the huge progress achieved in the past years, a number of obstacles still hamper the therapeutic efficacy of this synergistic modality such as uneven heat distribution, lack of targetability of anti-cancer agents and dosage-related side effects. Thus, developing a nanoplatform for targeted drug delivery against cancer is of great necessity. Herein, a lipid-polymer hybrid nanosystem (LP/ID) based on polyethyleneimine (PEI)-lecithin-polyethylene glycol (PEG) was fabricated to co-load indocyanine green (ICG) and dichloroacetate (DCA) for combined photothermal/chemotherapy. DCA and ICG were linked to the PEI backbone to form a dense hydrophobic core through amide bonds and electrostatic interactions, which increased the payload of DCA and ICG as well as achieved enzyme-responsive drug release because of the overexpressed amidase in tumor cells. Lecithin and DSPE-PEG₂₀₀₀ self-assembled around the hydrophobic complexes to obtain prolonged blood circulation and attenuated systemic toxicity of the hybrid nanosystem. The prepared LP/ID exhibited favourable stability in a physiological environment, good tumor imaging properties, and satisfactory photothermal/chemotherapeutic performance. Moreover, LP/ID could also enhance the cellular uptake and tumor retention capacity in comparison with free drug administration. Notably, by co-loading two therapeutic agents with different anti-cancer mechanisms, an obvious inhibitory effect on tumor growth was observed with negligible damage to normal tissues and organs because of the synergistic photothermal/chemotherapy effect, indicating the great potential of LP/ID as a robust nanoplatform for cancer treatment.

Combining nanotechnology with the multifunctional roles of neutrophils against cancer and inflammatory disease

Neutrophils, the most abundant leukocytes in humans, play a crucial role in acute inflammation during infection and tumorigenesis. Neutrophils are the major types of cells recruited to the inflammation sites induced by pathogens, exhibiting great homing ability towards inflammatory disorders and tumor sites. Therefore, a neutrophil-based drug delivery system (NDDS) has become a promising platform for anti-cancer and anti-inflammatory treatment. Recent decades have witnessed the huge progress of applying nanomaterials in drug delivery. Nanomaterials are regarded as innovative components to enrich the field of neutrophil-based therapies due to their unique physiochemical characteristics. In this review, the latest advancement of combining diverse nanomaterials with an NDDS for cancer and inflammatory disease treatment will be summarized. It is discussed how nanomaterials empower the therapeutic area of an NDDS and how an NDDS circumvents the limitations of nanomaterials. Moreover, based on the finding that neutrophils are closely involved in the progression of cancer and inflammatory diseases, emerging therapeutic strategies that target neutrophils will be outlined. Finally, as neutrophils were demonstrated to play a central role in the immunopathology of COVID-19, which causes necroinflammation that is responsible for the cytokine storm and sepsis during coronavirus infections, novel therapeutic approaches that anchor neutrophils against the pathological consequences related to COVID-19 will be highlighted as well.

Insights on functionalized carbon nanotubes for cancer theranostics

Despite the exciting breakthroughs in medical technology, cancer still accounts for one of the principle triggers of death and conventional therapeutic modalities often fail to attain an effective cure. Recently, nanobiotechnology has made huge advancement in cancer therapy with gigantic application potential because of their ability in achieving precise and controlled drug release, elevating drug solubility and reducing adverse effects. Carbon nanotubes (CNTs), one of the most promising carbon-related nanomaterials, have already achieved much success in biomedical field. Due to their excellent optical property, thermal and electronic conductivity, easy functionalization ability and high drug loading capacity, CNTs can be applied in a multifunctional way for cancer treatment and diagnosis. In this review, we will give an overview of the recent progress of CNT-based drug delivery systems in cancer theranostics, which emphasizes their targetability to intracellular components of tumor cells and extracellular elements in tumor microenvironment. Moreover, a detailed introduction on how CNTs penetrate inside the tumor cells to reach their sites of action and achieve the therapeutic effects, as well as their diagnostic applications will be highlighted.

Superstable and Large-Scalable Organosilica-Micellar Hybrid Nanosystem via a Confined Gelation Strategy for Ultrahigh-Dosage Chemotherapy

Although various drug nanocarriers have been developed for treating solid tumors, their clinical transformation is greatly limited by the difficulties in quantity production and unpredictable in vivo toxic effects. Herein, a facile "confined-gelation" strategy is developed to quantity-produce intelligent pluronic organosilica micelles (designated as IPOMs) with an undetectable critical micelle concentration (CMC), which features the self-assembly induced core confinement by block copolymers, the inner hydrolysis-condensation of silane to the oligomer skeleton, and oxidative cross-linking of disulfide skeleton to core gelation. The docetaxel-loaded IPOMs (DTX@IPOMs) with precise glutathione (GSH) responsiveness not only display an ultrahigh tolerated dose (360 mg/kg) in healthy Kunming mice model but also exhibit a remarkable tumor inhibition efficacy in both subcutaneous and orthotopic mice tumor models upon an extraordinarily large dosage (50 mg/kg). The present confined-gelation strategy provides a novel pathway to design and quantity-produce low-toxic and high-efficacy organic-inorganic hybrid nanodrugs in future clinical transformations.

Fabrication of aminated poly(glycidyl methacrylate)-based polymers for co-delivery of anticancer drugs and the p53 gene

Aminated poly(glycidyl methacrylate)s-based polymers for gene delivery not only can reduce toxicity and improve solubility, but can improve gene transfection efficiency and reduce protein aggregation. In this study, we first prepared poly(glycidyl methacrylate) (PGMA) via reversible addition-fragmentation chain transfer (RAFT) polymerization, and then the obtained PGMA homopolymer was post-modified with ethanol amine (EA), 1-amino-2-propanol (AP), 3-(dibutylamino)propylamine (DA) and N-(2-hydroxyethyl)ethylenediamine (HA), respectively, to yield four kinds of PGMA-based gene vectors containing hydroxyl groups (abbreviated as PGEA, PGAP, PGDA and PGHA). The effects of the different side chains and hydroxyl groups on the biological properties of these four cationic polymers were investigated. We found that the transfection efficiency of the PGHA/p53 complex was higher than those of the other three polymer/gene complexes through MTT assay and laser scanning confocal microscopy. Hence, we chose HA for further post-modification to fabricate a cationic copolymer, PCL-ss-P(PEGMA-co-GHA) (abbreviated as PGHAP), via a combination of ring opening polymerization (ROP) and RAFT copolymerization. The PCL-ss-P(PEGMA-co-GHA) amphiphilic copolymer could self-assemble into nanoparticles, which could be used to encapsulate anticancer drug doxorubicin (DOX) and compress the p53 gene to form the DOX-loaded PCL-ss-P(PEGMA-co-GHA)/p53 complex (abbreviated as DPGHAP/p53). The gel retardation assay showed that p53 gene could be well immobilized and remained stable under the electronegative conditions. MTT assay showed that the DPGHAP/p53 complex had a significant antitumor effect on A549 cells and H1299 cells compared with free DOX or/and p53 gene therapy alone. Furthermore, the test results from live cell imaging systems revealed that the DPGHAP/p53 complexes could effectively deliver DOX and the p53 gene into A549 cells. Therefore, the constructed cationic polymer PCL-ss-P(PEGMA-co-GHA) has potential application prospects as a co-vector of anticancer drugs and genes.

Reconstituted high density lipoprotein (rHDL), a versatile drug delivery nanoplatform for tumor targeted therapy

rHDL is a synthesized drug delivery nanoplatform exhibiting excellent biocompatibility, which possesses most of the advantages of HDL. rHDL shows almost no toxicity and can be degraded to non-toxic substances in vivo. The severe limitation of the application of various antitumor agents is mainly due to their low bioavailability, high toxicity, poor stability, etc. Favorably, antitumor drug-loaded rHDL nanoparticles (NPs), which are known as an important drug delivery system (DDS), help to change the situation a lot. This DDS shows an outstanding active-targeting ability towards tumor cells and improves the therapeutic effect during antitumor treatment while overcoming the shortcomings mentioned above. In the following text, we will mainly focus on the various applications of rHDL in tumor targeted therapy by describing the properties, preparation, receptor active-targeting ability and antitumor effects of antineoplastic drug-loaded rHDL NPs.

Serum protein-based nanoparticles for cancer diagnosis and treatment

Serum protein as naturally essential biomacromolecules has recently emerged as a versatile carrier for diagnostic and therapeutic drug delivery for cancer nanomedicine with superior biocompatibility, improved pharmacokinetics and enhanced targeting capacity. A variety of serum proteins have been utilized for drug delivery, mainly including albumin, ferritin/apoferritin, transferrin, low-density lipoprotein, high-density lipoprotein and hemoglobin. As evidenced by the success of paclitaxel-bound albumin nanoparticles (Abraxane^TM), serum protein-based nanoparticles have gained attractive attentions for precise biological design and potential clinical application. In this review, we summarize the general design strategies, targeting mechanisms and recent development of serum protein-based nanoparticles in the field of cancer nanomedicine. Moreover, we also concisely specify the current challenges to be addressed for a bright future of serum protein-based nanomedicines.

Development of synthetic high-density lipoprotein-based ApoA-I mimetic peptide-loaded docetaxel as a drug delivery nanocarrier for breast cancer chemotherapy

In this study, a synthetic high-density lipoprotein (sHDL), peptide-based nanocarrier loaded with docetaxel (DTX) was constructed, against breast cancer. The thermodynamic and molecular dynamic analyses were conducted to examine the stability of nanoparticles synthesized from mimetic peptide 5 A and various types of phospholipids. Furthermore, the cellular uptake and in vivo fluorescence imaging analysis experiments, with scavenger receptor B-I (SR-BI) were carried out to examine the tumor-targeting ability of sHDL. The nanoparticles were investigated for their pharmacodynamic and cytotoxic effects to show their effectivity as anti-tumor agents. The results showed that the synthesized sHDL nanoparticles exhibited a high payload of DTX, sustained drug release properties, and excellent biocompatibility. Moreover, DTX-sHDL nanoparticles enhanced the uptake of DTX, increased the cytotoxicity against MCF-7 cells, and reduced the off-target side-effects to normal cells. Finally, experiments in 4T1 cell line-bearing mice indicate that inhibition of tumor growth by DTX-sHDL nanoparticles was superior to that of free DTX group. Thus, the sHDL nanoparticles are a promising drug delivery vehicle for improving the efficacy of anti-cancer drugs.

Cancer-Cell-Membrane-Coated Nanoparticles with a Yolk-Shell Structure Augment Cancer Chemotherapy

Despite rapid advancements in antitumor drug delivery, insufficient intracellular transport and subcellular drug accumulation are still issues to be addressed. Cancer cell membrane (CCM)-camouflaged nanoparticles (NPs) have shown promising potential in tumor therapy due to their immune escape and homotypic binding capacities. However, their efficacy is still limited due to inefficient tumor penetration and compromised intracellular transportation. Herein, a yolk-shell NP with a mesoporous silica nanoparticle (MSN)-supported PEGylated liposome yolk and CCM coating, CCM@LM, was developed for chemotherapy and exhibited a homologous tumor-targeting effect. The yolk-shell structure endowed CCM@LM with moderate rigidity, which might contribute to the frequent transformation into an ellipsoidal shape during infiltration, leading to facilitated penetration throughout multicellular spheroids in vitro (up to a 23.3-fold increase compared to the penetration of membrane vesicles). CCM@LM also exhibited a cellular invasion profile mimicking an enveloped virus invasion profile. CCM@LM was directly internalized by membrane fusion, and the PEGylated yolk (LM) was subsequently released into the cytosol, indicating the execution of an internalization pathway similar to that of an enveloped virus. The incoming PEGylated LM further underwent efficient trafficking throughout the cytoskeletal filament network, leading to enhanced perinuclear aggregation. Ultimately, CCM@LM, which co-encapsulated low-dose doxorubicin and the poly(ADP-ribose) polymerase inhibitor, mefuparib hydrochloride, exhibited a significantly stronger antitumor effect than the first-line chemotherapeutic drug Doxil. Our findings highlight that NPs that can undergo facilitated tumor penetration and robust intracellular trafficking have a promising future in cancer chemotherapy.

A TRAIL-Delivered Lipoprotein-Bioinspired Nanovector Engineering Stem Cell-Based Platform for Inhibition of Lung Metastasis of Melanoma

Genetically engineered mesenchymal stem cells (MSCs), as non-viral gene delivery platforms, are rapidly evolving in tumor therapy due to their low immunogenicity and natural tumor-homing capacity. Methods: In this paper, we selected reconstituted high-density lipoprotein (rHDL), a lipoprotein-bioinspired nanovector with specific binding ability to scavenger receptor B type I (SR-BI) expressed on MSCs, as a transfection agent to genetically modify MSCs. pDNA encoding tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL) was used as a functional gene to be transfected into the nucleus of MSCs for TRAIL expression. Lauric acid-coupled polyethyleneimine (PEI-LA) as an amphiphilic cationic polymer was synthesized to electrostatically bind to pDNA, and then incorporated into rHDL to form rHDL/PEI-LA/pDNA nanoparticles. Results: The nanoparticles exhibited homogenous particle size and excellent serum stability in vitro. Meanwhile, this SR-BI-targeted rHDL performed efficient intracellular gene delivery, specific lysosome-independent mechanism of cellular uptake and high transfection of pDNA towards MSCs. Moreover, high TRAIL expression in MSCs was detected after rHDL-mediated transfection. In vitro and in vivo results indicated that genetically engineered MSCs could accurately target to B16F10 cells, thereby producing significant apoptosis-inducing effect on aggressive melanoma. Conclusion: TRAIL-expressing MSCs engineered by rHDL nanovector was an efficient and hypotoxic method for stem cells-based pulmonary melanoma metastasis-targeting therapy.

Targeted multifunctional redox-sensitive micelle co-delivery of DNA and doxorubicin for the treatment of breast cancer

Drug/gene co-delivery carriers are a promising strategy for cancer treatment. Thus, herein, T7-conjugated redox-sensitive amphiphilic polyethylene glycol-polyethyleneimine-poly(caprolactone)-SS-poly(caprolactone)-polyethyleneimine-polyethylene glycol (PEG-PEI-PCL-SS-PCL-PEG) (PPPT) is designed to realize the co-delivery of pORF-hTRAIL and DOX efficiently into tumor cells. PPPT is synthesized via the ring opening polymerization (ROP) of ε-caprolactone followed by Michael addition polymerization and atom transfer radical polymerization (ATRP) of the maleic imide group of MAL-PEG-NHS. The PPPT micelles present a spherical or ellipsoidal geometry with a mean diameter of approximately 100-120 nm. Meanwhile, they also exhibit a redox-responsive drug release profile in vitro. The blood compatibility and complement activation tests reveal that the PPPT micelles do not induce blood hemolysis, blood clotting, or complement activation. The T7-modified co-delivery system shows a higher cellular uptake efficiency than the unmodified co-delivery system in human breast cancer MCF-7 cells and is accumulated in tumor more efficiently in vivo. These results suggest that the T7-targeted codelivery system of DOX and pORF-hTRAIL is a combined delivery platform that can significantly improve the treatment of breast cancer.