Supramolecular self-assembly forming a multifunctional synergistic system for targeted co-delivery of gene and drug

A supramolecular colloidal system based on folate-conjugated β-cyclodextrin polymer and indocyanine green for enhanced tumor-targeted cell imaging in 2D culture and 3D tumor spheroids

Indocyanine green (ICG) is an FDA-approved medical diagnostic agent that is widely used as a near-infrared (NIR) fluorescent imaging molecular probe. However, ICG tends to aggregate to form dimers or H-aggregates in water and lacks physical and optical stability, which greatly decreases its absorbance and fluorescence intensity in various applications. Additionally, ICG has no tissue- or tumor-targeting properties, and its structure is not easy to modify, which has further limited its application in cancer diagnosis. In this study, we addressed these challenges by developing a supramolecular colloidal carrier system that targets tumor cells. To this end, we synthesized a water-soluble β-cyclodextrin (β-CD) polymer conjugated with folate (FA), denoted PCD-FA, which is capable of forming inclusion complexes with ICG in water through host-guest interactions between the β-CD moieties and ICG molecules. The inclusion complexes formed by PCD-FA and ICG, called ICG@PCD-FA, dispersed stably in solution as colloidal nanoparticles, greatly improving the physical and optical properties of ICG by preventing ICG dimer formation, where ICG appeared as monomers and even J-aggregates. This resulted in stronger and more stable absorption at a longer wavelength of 900 nm, which may allow for deeper tissue penetration and imaging with reduced interference from biological tissues' autofluorescence. Moreover, ICG@PCD-FA showed a targeting effect on folate receptor-positive (FR+) tumor cells, which specifically highlighted FR+ cells via NIR endoscopic imaging. Notably, ICG@PCD-FA further improved permeation and accumulation in FR+ 3D tumor spheroids. Therefore, this ICG@PCD-FA supramolecular colloidal system may have a great potential for use in tumor NIR imaging and diagnostic applications.

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.

Bifunctional drug delivery system with carbonic anhydrase IX targeting and glutathione-responsivity driven by host-guest amphiphiles for effective tumor therapy

It remains a critical issue to deliver anticancer drugs to tumor tissues and reducing the toxic effects on normal tissues. The drug delivery system (DDS) based on self-assembly provides a multi-functional way for drug delivery. In this work, a supramolecular host (L-CD) with targeting function based on a β-cyclodextrin (β-CD) backbone was synthesized with carbonic anhydrase IX (CAIX) overexpressed on tumor cells as a target, and the methotrexate prodrug (MTX-SS-Ad) modified by adamantane and disulfide bond was prepared to be used as the guest. The amphiphilic complex was prepared between L-CD and MTX-SS-Ad through host-guest interactions and could further self-assemble into supramolecular nanoparticles (SNPs) with active targeting and stimulus release functions. The interaction between host and guest was investigated by UV, NMR, IR, XRD and TGA. The characteristic of SNPs was observed by DLS and TEM. Throng the study of molecular docking, in vitro inhibition, cell uptake experiments, and western blotting, SNPs have showed CAIX inhibitory effects both inside and outside the cells. The in vitro release experiments indicated that SNPs can undergo disintegration and release drugs under acidic and GSH conditions. Moreover, SNP can effectively inhibit the proliferation of cancer cells without generating additional toxic side effects on normal cells. So, we provide a strategy of bifunctional drug delivery system with targeting and glutathione-responsivity for effective tumor therapy.

A Multi-Layer Breast Cancer Model to Study the Synergistic Effect of Photochemotherapy

Breast cancer is one of the most common cancers among women. The development of new and effective therapeutic approaches in the treatment of breast cancer is an important challenge in modern oncology. Two-dimensional (2D) cell cultures are most often used in the study of compounds with potential anti-tumor nature. However, it is necessary to develop advanced three-dimensional (3D) cell models that can, to some extent, reflect the physiological conditions. The use of miniature cancer-on-a-chip microfluidic systems can help to mimic the complex cancer microenvironment. In this report, we developed a 3D breast cancer model in the form of a cell multilayer, composed of stromal cells (HMF) and breast cancer parenchyma (MCF-7). The developed cell model was successfully used to analyze the effectiveness of combined sequential photochemotherapy, based on doxorubicin and meso-tetraphenylporphyrin. We proved that the key factor that allows achieving the synergistic effect of combination therapy are the order of drug administration to the cells and the sequence of therapeutic procedures. To the best of our knowledge, studies on the effectiveness of combination photochemotherapy depending on the sequence of the component drugs were performed for the first time under microfluidic conditions on a 3D multilayered model of breast cancer tissue.

Cyclodextrin-Based Polymeric Drug Delivery Systems for Cancer Therapy

Cyclodextrins (CDs) are one of the most extensively studied cyclic-oligosaccharides due to their low toxicity, good biodegradability and biocompatibility, facile chemical modification, and unique inclusion capacity. However, problems such as poor pharmacokinetics, plasma membrane disruption, hemolytic effects and a lack of target specificity still exist for their applications as drug carriers. Recently, polymers have been introduced into CDs to combine the advantages of both biomaterials for the superior delivery of anticancer agents in cancer treatment. In this review, we summarize four types of CD-based polymeric carriers for the delivery of chemotherapeutics or gene agents for cancer therapy. These CD-based polymers were classified based on their structural properties. Most of the CD-based polymers were amphiphilic with the introduction of hydrophobic/hydrophilic segments and were able to form nanoassemblies. Anticancer drugs could be included in the cavity of CDs, encapsulated in the nanoparticles or conjugated on the CD-based polymers. In addition, the unique structures of CDs enable the functionalization of targeting agents and stimuli-responsive materials to realize the targeting and precise release of anticancer agents. In summary, CD-based polymers are attractive carriers for anticancer agents.

Nanoparticles design considerations to co-deliver nucleic acids and anti-cancer drugs for chemoresistance reversal

Chemoresistance and hence the consequent treatment failure is considerably challenging in clinical cancer therapeutics. The understanding of the genetic variations in chemoresistance acquisition encouraged the use of gene modulatory approaches to restore anti-cancer drug efficacy. Many smart nanoparticles are designed and optimized to mediate combinational therapy between nucleic acid and anti-cancer drugs. This review aims to define a rational design of such co-loaded nanocarriers with the aim of chemoresistance reversal at various cellular levels to improve the therapeutic outcome of anticancer treatment. Going through the principles of therapeutics loading, physicochemical characteristics tuning, and different nanocarrier modifications, also looking at combination effectiveness on chemosensitivity restoration. Up to now, these emerging nanocarriers are in development status but are expected to introduce outstanding outcomes.

A pH-responsive complex based on supramolecular organic framework for drug-resistant breast cancer therapy

Chemotherapy is one of the main ways to treat breast cancer clinically. However, the multidrug resistance to anti-tumor drugs limits their clinical use. To overcome these drawbacks, the development of drug delivery systems (DDSs) has attracted more and more attention in cancer therapy. At present, the preparation and purification process are complicated for many reported DDSs, while the clinic calls for new DDSs that are more convenient for preparation. Here a new pH-responsive supramolecular organic framework drug delivery complex loading doxorubicin (DOX) is fabricated. Anti-tumor activity of the system in vitro was investigated by cell cytotoxicity, uptake assay, and cell apoptosis analysis. The anti-tumor activity in vivo was investigated by inspecting nude mice body weight, tumor volume and weight, also a preliminary mechanism probe was conducted by HE and TUNEL staining. The DOX@SOF displayed high stability, good biocompatibility and pH-regulated drug release. At acid condition, the hydrazone bonds would be broken, which result in the dissociation of SOF, and then the drugs would be released from the system. Furthermore, DOX@SOF enhanced cellular internalization. Both in vitro and in vivo experiments reflected that DOX@SOF could enhance the anti-tumor activity of DOX. for the MCF-7/ADR tumor cells and tumors. This study provides a highly efficient strategy to prepare a stimulus-responsive supramolecular drug delivery complex for the treatment of drug-resistant cancer, the results presented inspiring scientific interests in exploring new drug delivery strategies and reversing multi-drug resistance for clinical chemotherapy.

"Targeting Design" of Nanoparticles in Tumor Therapy

Tumor-targeted therapy based on nanoparticles is a popular research direction in the biomedical field. After decades of research and development, both the passive targeting ability of the inherent properties of NPs and the active targeting based on ligand receptor interaction have gained deeper understanding. Unfortunately, most targeted delivery strategies are still in the preclinical trial stage, so it is necessary to further study the biological fate of particles in vivo and the interaction mechanism with tumors. This article reviews different targeted delivery strategies based on NPs, and focuses on the physical and chemical properties of NPs (size, morphology, surface and intrinsic properties), ligands (binding number/force, activity and species) and receptors (endocytosis, distribution and recycling) and other factors that affect particle targeting. The limitations and solutions of these factors are further discussed, and a variety of new targeting schemes are introduced, hoping to provide guidance for future targeting design and achieve the purpose of rapid transformation of targeted particles into clinical application.

Smart Hydrogel Formed by Alginate-g-Poly(N-isopropylacrylamide) and Chitosan through Polyelectrolyte Complexation and Its Controlled Release Properties

Smart hydrogels that can respond to external stimuli such as temperature and pH have attracted tremendous interest for biological and biomedical applications. In this work, we synthesized two alginate-graft-poly(N-isopropylacrylamide) (Alg-g-PNIPAAm) copolymers and aimed to prepare smart hydrogels through formation of polyelectrolyte complex (PEC) between the negatively charged Alg-g-PNIPAAm copolymers and the positively charged chitosan (Cts) in aqueous solutions. The hydrogels were expected to be able to respond to both temperature and pH changes due to the nature of Alg-g-PNIPAAm and chitosan. The hydrogel formation was determined by a test tube inverting method and confirmed by the rheological measurements. The rheological measurements showed that the PEC hydrogels formed at room temperature could be further enhanced by increasing temperature over the lower critical solution temperature (LCST) of PNIPAAm, because PNIPAAm would change from hydrophilic to hydrophobic upon increasing temperature over its LCST, and the hydrophobic interaction between the PNIPAAm segments may act as additional physical crosslinking. The controlled release properties of the hydrogels were studied by using the organic dye rhodamine B (RB) as a model drug at different pH. The PEC hydrogels could sustain the RB release more efficiently at neutral pH. Both low pH and high pH weakened the PEC hydrogels, and resulted in less sustained release profiles. The release kinetics data were found to fit well to the Krosmyer–Peppas power law model. The analysis of the release kinetic parameters obtained by the modelling indicates that the release of RB from the PEC hydrogels followed mechanisms combining diffusion and dissolution of the hydrogels, but the release was mainly governed by diffusion with less dissolution at pH 7.4 when the PEC hydrogels were stronger and stabler than those at pH 5.0 and 10.0. Therefore, the PEC hydrogels are a kind of smart hydrogels holding great potential for drug delivery applications.

Stimulus-responsive drug/gene delivery system based on polyethylenimine cyclodextrin nanoparticles for potential cancer therapy

Combination therapy through simultaneous delivery of anti-cancer drugs and genes with nano-assembled structure has been proved to be a simple and effective approach for treating breast cancer. In this study, redox-sensitive folate-appended-polyethylenimine-β-cyclodextrin (roFPC) host-guest supramolecular nanoparticles (HGSNPs) were developed as a targeted co-delivery system of doxorubicin (Dox) and Human telomerase reverse transcriptase-small interfering RNA) hTERT siRNA) for potential cancer therapy. The nanotherapeutic system was prepared by loading adamantane-conjugated doxorubicin (Ad-Dox) into roFPC through the supramolecular assembly, followed by electrostatically-driven self-assembly between hTERT siRNA and roFPC/Ad-Dox. The roFPC' host-guest structures allow pH-dependent intracellular drug release in a sustained manner, as well as simultaneous and effective gene transfection. This co-delivery vector displayed combined anti-tumor properties of the Dox-enhanced gene transfection, good water-solubility, and biocompatibility, possesses considerably enhanced hemocompatibility, and especially targets folate receptor-positive cells only at low N/P levels to prompt effective cell apoptosis for cancer treatment.

Lignin-Based Nonviral Gene Carriers Functionalized by Poly[2-(Dimethylamino)ethyl Methacrylate]: Effect of Grafting Degree and Cationic Chain Length on Transfection Efficiency

Lignin is a natural renewable biomass resource with great potential for applications, while its development into high value-added molecules or materials is rare. The development of biomass lignin as potential nonviral gene delivery carriers was initiated by our group through the "grafting-from" approach. Firstly, the lignin was modified into macroinitiator using 2-bromoisobutyryl bromide. Then cationic polymer chains of poly[2-(dimethylamino)ethyl methacrylate] (PDMAEMA) were grown from the lignin backbone using atom transfer radical polymerization (ATRP) to yield lignin-PDMAEMA graft copolymers (LPs) with branched structure. To gain a deep understanding of the relationship between the nonviral gene transfection efficiency of such copolymers and their structural and compositional factors, herein eight lignin-based macroinitiators with different modification degrees (MDs, from 3.0 to 100%) were synthesized. Initiated by them, a series of 20 LPs were synthesized with varied structural factors such as grafting degree (GD, which is equal to MD, determining the cationic chain number per lignin macromolecule), cationic chain length (represented by number of repeating DMAEMA units per grafted arm or degree of polymerization, DP) as well as the content of N element (N%) which is due to the grafted PDMAEMA chains and proportional to molecular weight of the LPs. The in vitro gene transfection capability of these graft copolymers was evaluated by luciferase assay in HeLa, COS7 and MDA-MB-231cell lines. Generally, the copolymers LP-12 (N% = 7.28, MD = 36.7%, DP = 13.6) and LP-14 (N% = 6.05, MD = 44.4%, DP = 5.5) showed good gene transfection capabilities in the cell lines tested. Overall, the performance of LP-12 was the best among all the LPs in the three cell lines at the N/P ratios from 10 to 30, which was usually several times higher than PEI standard. However, in MDA-MB-231 at N/P ratio of 30, LP-14 showed the best gene transfection performance among all the LPs. Its gene transfection efficiency was ca. 11 times higher than PEI standard at this N/P ratio. This work demonstrated that, although the content of N element (N%) which is due to the grafted PDMAEMA chains primarily determines the gene transfection efficiency of the LPs, it is not the only factor in explaining the performance of such copolymers with the branched structure. Structural factors of these copolymers such as grafting degree and cationic chain length could have a profound effect on the copolymer performance on gene transfection efficiency. Through carefully adjusting these factors, the gene transfection efficiency of the LPs could be modulated and optimized for different cell lines, which could make this new type of biomass-based biomaterial an attractive choice for various gene delivery applications.

A pH-responsive complex based on supramolecular organic framework for drug-resistant breast cancer therapy

Chemotherapy is one of the main ways to treat breast cancer clinically. However, the multidrug resistance to anti-tumor drugs limits their clinical use. To overcome these drawbacks, development of drug delivery systems (DDSs) has attracted more and more attention in cancer therapy. At present, the preparation and purification process are complicated for many reported DDSs, while clinic calls for new DDSs that are more convenient for preparation. Here, a new pH-responsive supramolecular organic framework drug delivery complex loading doxorubicin (DOX) is fabricated. Anti-tumor activity of the system in vitro was investigated by cell cytotoxicity, uptake assay, and cell apoptosis analysis. The anti-tumor activity in vivo was investigated by inspecting nude mice body weight, tumor volume, and weight, also a preliminary mechanism probe was conducted by HE and TUNEL staining. The DOX@SOF displayed high stability, good biocompatibility, and pH regulated drug release. At acid condition, the hydrazone bonds would be broken, which result in the dissociation of SOF, and then the drugs would be released from the system. Furthermore, DOX@SOF enhanced cellular internalization. Both in vitro and in vivo experiments reflected that DOX@SOF could enhance the anti-tumor activity of DOX for the MCF-7/ADR tumor cells and tumors. This study provides a highly efficient strategy to prepare stimulus-responsive supramolecular drug delivery complex for treatment of drug-resistant cancer, the results presented inspiring scientific interests in exploring new drug delivery strategy and reversing multi-drug resistance for clinical chemotherapy.

Supramolecular Surface Functionalization of Iron Oxide Nanoparticles with α-Cyclodextrin-Based Cationic Star Polymer for Magnetically-Enhanced Gene Delivery

Supramolecular polymers formed through host-guest complexation have inspired many interesting developments of functional materials for biological and biomedical applications. Here, we report a novel design of a non-viral gene delivery system composed of a cationic star polymer forming supramolecular complexes with the surface oleyl groups of superparamagnetic iron oxide nanoparticles (SPIONs), for magnetically enhanced delivery of DNA into mammalian cells. The cationic star polymer was synthesized by grafting multiple oligoethylenimine (OEI) chains onto an α-cyclodextrin (α-CD) core. The SPIONs were synthesized from iron(III) acetylacetonate and stabilized by hydrophobic oleic acid and oleylamine in hexane, which were characterized in terms of their size, structure, morphology, and magnetic properties. The synthesized magnetic particles were found to be superparamagnetic, making them a suitable ferrofluid for biological applications. In order to change the hydrophobic surface of the SPIONs to a hydrophilic surface with functionalities for plasmid DNA (pDNA) binding and gene delivery, a non-traditional but simple supramolecular surface modification process was used. The α-CD-OEI cationic star polymer was dissolved in water and then mixed with the SPIONs stabilized in hexane. The SPIONs were "pulled" into the water phase through the formation of supramolecular host-guest inclusion complexes between the α-CD unit and the oleyl surface of the SPIONs, while the surface of the SPIONs was changed to OEI cationic polymers. The α-CD-OEI-SPION complex could effectively bind and condense pDNA to form α-CD-OEI-SPION/pDNA polyplex nanoparticles at the size of ca. 200 nm suitable for delivery of genes into cells through endocytosis. The cytotoxicity of the α-CD-OEI-SPION complex was also found to be lower than high-molecular-weight polyethylenimine, which was widely studied previously as a standard non-viral gene vector. When gene transfection was carried out in the presence of an external magnetic field, the α-CD-OEI-SPION/pDNA polyplex nanoparticles greatly increased the gene transfection efficiency by nearly tenfold. Therefore, the study has demonstrated a facile two-in-one method to make the SPIONs water-soluble as well as functionalized for enhanced magnetofection.

Co-delivery of paclitaxel and STAT3 siRNA by a multifunctional nanocomplex for targeted treatment of metastatic breast cancer

Metastasis is one of the major causes of mortality in patients suffering from breast cancer. The signal transducer and activator of transcription 3 (STAT3) is closely related to cancer metastasis. Herein, a multifunctional nanocomplex was developed to simultaneously deliver paclitaxel (PTX) and STAT3 siRNA (siSTAT3) to inhibit tumor growth and prevent metastasis of breast cancer cells. PTX was encapsulated into the synthesized polyethyleneimine-polylactic acid-lipoic acid (PPL) micelle through hydrophobic interaction, while siSTAT3 was condensed onto polyethyleneimine through electrostatic interaction. The surface charge of the drug-loaded nanocomplex (^siSTAT3PPL_PTX) was then converted to negative by coating with hyaluronic acid (HA). The multifunctional nanocomplex (HA/^siSTAT3PPL_PTX) effectively entered CD44-overexpressed 4T1 cells via an active targeting mechanism. HA shell was degraded by the concentrated hyaluronidase in the endo/lysosome and the rapid drug release was triggered by the redox micro-environment of cytoplasm. Moreover, HA/^siSTAT3PPL_PTX showed enhanced cytotoxicity against tumor cells due to a synergistic effect of PTX and siSTAT3. The effective inhibition of tumor metastasis was confirmed by in vitro cell migration and invasion in 4T1 cells. More importantly, a superior antitumor efficacy was observed in orthotopic 4T1 tumor-bearing mice, with no side effects in major organs, and the lung metastasis was strongly inhibited in 4T1 metastasis model. In conclusion, the multifunctional nanocomplex provides a versatile platform for efficient treatment of metastatic cancer through tumor-targeted chemo-gene combined therapy. STATEMENT OF SIGNIFICANCE: Metastasis is one of the major causes of mortality in patients suffering from breast cancer. The signal transducer and activator of transcription 3 (STAT3) is closely related to cancer metastasis. In this study, a multifunctional nanocomplex co-loaded with paclitaxel (PTX) and STAT3 siRNA was constructed and characterized. The co-delivery system exhibited active tumor targeting, effective endo/lysosomal escape, and rapid intracellular drug release. Both in vitro and in vivo studies indicated that the nanocomplex could lead to superior tumor growth inhibition, as well as metastasis suppression by silencing expression of STAT3 and p-STAT3. This present study implies that the nanocomplex could be a potential platform for targeted treatment of metastatic cancer through chemo-gene combined therapy.

Polydopamine nanoparticles with different sizes for NIR-promoted gene delivery and synergistic photothermal therapy

The combination of photothermal therapy and gene therapy has received increasing attention in tumor treatment. However, how to improve synergistic efficacy has become a new challenge. NIR light has a great potential in tumor treatment because of its considerable penetration depth and spatiotemporal controllability. Polydopamine is a popular photothermal conversion agent, which has desirable photothermal conversion ability and good biocompatibility. In this research, polydopamine-polyethyleneimine nanoparticles with diameters of 13 nm (SPPNPs) and 236 nm (LPPNPs) were prepared as gene carriers. The size of polydopamine nanoparticles had great effect on the complexes formation, photothermal conversion ability and gene transfection efficiency. After loading gene, the SPPNPs/gene and LPPNPs/gene complexes were about 60-80 nm and 240 nm respectively, indicating different styles of complexes formation. Both SPPNPs/gene and LPPNPs/gene complexes without NIR irradiation could achieve similar gene transfection efficiency as commercial lipofectamine 2000, while with lower cytotoxicity. Due to better photothermal conversion ability, the transfection level of LPPNPs/pGL-3 complexes increased to 4.5 times after NIR irradiation (2.6 W/cm², 15 min), which ascribed to the quick escape of gene complexes from the endosome. The produced heat under NIR irradiation could also ablate tumor cells. So LPPNPs were chosen to deliver tumor suppressor gene p53 DNA to investigate the synergistic efficacy of gene/photothermal therapy. The tumor in KB tumor-bearing mice was almost eliminated after intratumoral injection, and the tumor inhibition efficacy of gene/photothermal synergistic therapy achieved to 99%. By combining NIR-promoted gene transfection and gene/photothermal synergistic therapy, the LPPNPs hold great promise in practical tumor treatment.

Polymeric Delivery of Therapeutic Nucleic Acids

The advent of genome editing has transformed the therapeutic landscape for several debilitating diseases, and the clinical outlook for gene therapeutics has never been more promising. The therapeutic potential of nucleic acids has been limited by a reliance on engineered viral vectors for delivery. Chemically defined polymers can remediate technological, regulatory, and clinical challenges associated with viral modes of gene delivery. Because of their scalability, versatility, and exquisite tunability, polymers are ideal biomaterial platforms for delivering nucleic acid payloads efficiently while minimizing immune response and cellular toxicity. While polymeric gene delivery has progressed significantly in the past four decades, clinical translation of polymeric vehicles faces several formidable challenges. The aim of our Account is to illustrate diverse concepts in designing polymeric vectors towards meeting therapeutic goals of in vivo and ex vivo gene therapy. Here, we highlight several classes of polymers employed in gene delivery and summarize the recent work on understanding the contributions of chemical and architectural design parameters. We touch upon characterization methods used to visualize and understand events transpiring at the interfaces between polymer, nucleic acids, and the physiological environment. We conclude that interdisciplinary approaches and methodologies motivated by fundamental questions are key to designing high-performing polymeric vehicles for gene therapy.

A Novel Targeted Therapy System for Cervical Cancer: Co-Delivery System of Antisense LncRNA of MDC1 and Oxaliplatin Magnetic Thermosensitive Cationic Liposome Drug Carrier

BACKGROUND

This study was aimed to prepare a novel magnetic thermosensitive cationic liposome drug carrier for the codelivery of Oxaliplatin (OXA) and antisense lncRNA of MDC1 (MDC1-AS) to Cervical cancer cells and evaluate the efficiency of this drug carrier and its antitumor effects on Cervical cancer.

METHODS

Thermosensitive magnetic cationic liposomes were prepared using thin-film hydration method. The OXA and MDC1-AS vectors were loaded into the codelivery system, and the in vitro OXA thermosensitive release activity, efficiency of MDC1-AS regulating MDC1, in vitro cytotoxicity, and in vivo antitumor activity were determined.

RESULTS

The codelivery system had desirable targeted delivery efficacy, OXA thermosensitive release, and MDC1-AS regulating MDC1. Codelivery of OXA and MDC1-AS enhanced the inhibition of cervical cancer cell growth in vitro and in vivo, compared with single drug delivery.

CONCLUSION

The novel codelivery of OXA and MDC1-AS magnetic thermosensitive cationic liposome drug carrier can be applied in the combined chemotherapy and gene therapy for cervical cancer.

Co-delivery Systems of Multiple Drugs Using Nanotechnology for Future Cancer Therapy

Cancer treatments have improved significantly during the last decade but are not yet satisfactory. Combination therapy is often administered to improve efficacy and safety. Drug delivery systems can also improve efficacy and safety. To control the spatiotemporal distribution of drugs, nanotechnology involving liposomes, solid lipid nanoparticles, and polymeric micelles has been developed. Co-delivery systems of multiple drugs are a promising approach to combat cancer. Synergistic effects and reduced side effects are expected from the use of co-delivery systems. In this review, we summarize various co-delivery systems for multiple drugs, including small-molecule drugs, nucleic acids, genes, and proteins. Co-delivery of drugs with different properties is relatively difficult, but some researchers have succeeded in developing such co-delivery systems. Environment-responsive carrier designs can control the release of cargos. Although their preparation is more complicated than that of mono-delivery systems, co-delivery systems can simplify clinical procedures and improve patient QOL.

Folic Acid/Peptides Modified PLGA-PEI-PEG Polymeric Vectors as Efficient Gene Delivery Vehicles: Synthesis, Characterization and Their Biological Performance

Polymeric vectors are safer alternatives for gene delivery owing to their advantages as compared to viral vectors. To improve the stability and transfection efficiency of poly(lactic-co-glycolic acid) (PLGA)- and poly(ethylenimine) (PEI)-based vectors, poly(ethylene glycol) (PEG), folic acid (FA), arginylglycylaspartic acid (RGD) peptides and isoleucine-lysine-valine-alanine-valine (IKVAV) peptides were employed and PLGA-PEI-PEG-FA and PLGA-PEI-PEG-RGD copolymers were synthesized. PLGA-PEI-PEG-FA/DNA, PLGA-PEI-PEG-RGD/DNA and PLGA-PEI-PEG-RGD/IKVAV/DNA nanocomplexes (NCs) were formed through bulk mixing. The structure and properties, including morphology, particle size, surface charge and DNA encapsulation, of NCs were studied. Robust NCs with spherical shape, uniform size distribution and slightly positive charge were able to completely bind DNA above their respective N/P ratios. The critical N/P ratio for PLGA-PEI-PEG-FA/DNA, PLGA-PEI-PEG-RGD/DNA and PLGA-PEI-PEG-RGD/IKVAV/DNA NCs was identified to be 12:1, 8:1 and 10:1, respectively. The covalent modification of PEI through a combination of biodegradable PLGA, hydrophilic PEG and targeting motifs significantly decreased the cytotoxicity of PEI. The developed NCs showed both N/P ratio and cell type-dependent transfection efficiency. An increase in N/P ratio resulted in increased transfection efficiency, and much improved transfection efficiency of NCs was observed above their respective critical N/P ratios. This study provides a promising means to produce polymeric vectors for gene delivery.

A supramolecular platform for controlling and optimizing molecular architectures of siRNA targeted delivery vehicles

It requires multistep synthesis and conjugation processes to incorporate multifunctionalities into a polyplex gene vehicle to overcome numerous hurdles during gene delivery. Here, we describe a supramolecular platform to precisely control, screen, and optimize molecular architectures of siRNA targeted delivery vehicles, which is based on rationally designed host-guest complexation between a β-cyclodextrin-based cationic host polymer and a library of guest polymers with various PEG shape and size, and various density of ligands. The host polymer is responsible to load/unload siRNA, while the guest polymer is responsible to shield the vehicles from nonspecific cellular uptake, to prolong their circulation time, and to target tumor cells. A series of precisely controlled molecular architectures through a simple assembly process allow for a rapid optimization of siRNA delivery vehicles in vitro and in vivo for therapeutic siRNA-Bcl2 delivery and tumor therapy, indicating the platform is a powerful screening tool for targeted gene delivery vehicles.

Novel Chitosan Derivatives with Reversible Cationization and Hydrophobicization for Tumor Cytoplasm-Specific Burst Co-delivery of siRNA and Chemotherapeutics

Despite the great potential of combination therapy based on siRNA and chemotherapeutics, an efficient vehicle with abilities of well drug co-loading, synchronizing in vivo trafficking, and target-specific co-burst release remains elusive, which results in a suboptimal synergistic potency. Herein, a novel chitosan amphiphile (PEI-ss-HECS-ss-OA, HSPO) with glutathione (GSH)-reversible cationization and hydrophobicization by polyethylenimine (PEI) and octylamine (OA), respectively, was developed for this purpose. HSPO spontaneously assembled in aqueous solution to be a micellar system and effectively co-encapsulated the two drugs with an adjustable dosage ratio. With a surface charge inversion strategy by hyaluronic acid (HA) coating, the HA(HSPO) co-delivery micelles with a negative surface charge (-21.45 ± 1.44 mV) and suitable size (192.52 ± 7.41 nm) selectively accumulated into CD44 overexpressed A549 tumors through a combination of passive and active targeting mechanism. Then, tumor cytoplasm-selective co-burst release was obtained through GSH triggered collapse of the amphiphilic assembly alongside a decrease of positive charge condensation, finally leading to an enhanced synergistic antitumor effect with a superior inhibition ratio of 86.63%. Overall, this study validated the great promise of HSPO as an efficient site-specific rapid co-trafficking vehicle of siRNA and chemotherapeutics for a remarkable synergistic tumor inhibition.

Ligand targeting and peptide functionalized polymers as non-viral carriers for gene therapy

Ligand targeting and peptide functionalized polymers serve as gene carriers for efficient gene delivery.

Supramolecular prodrugs based on host–guest interactions

The concept, detailed progress, advantages and opportunities of supramolecular drugs via host–guest chemistry are summarized.

Diblock brush-arm star copolymers via a core-first/graft-from approach using γ-cyclodextrin and ROMP: a modular platform for drug delivery

Water-soluble diblock brush-arm star copolymers using γ-CD-based core-first ring-opening metathesis polymerization, allowing for anticancer drug delivery via host–guest interaction.

Synergistic effect of the combination therapy on ovarian cancer cells under microfluidic conditions

Ovarian cancer belongs to the group of gynecological cancers and indicates the high resistance to many drugs used in standard anticancer therapy. The treatment of ovarian cancer is a big challenge for the present medicine. In our report we tested the effectiveness of the combination anticancer therapy against ovarian cells: human ovarian carcinoma (A2780) and human ovarian fibroblasts (HOF). Two different types of drugs were used: doxorubicin (DOX) and a new-generation photosensitizer, nanoencapsulated meso-tetraphenylporphyrin (nano-TPP). The aim of the research was to compare the effect of the sequential combination therapy (chemotherapy with DOX and photodynamic therapy with nano-TPP) carried out in static and dynamic conditions. To achieve dynamic culture conditions, similar to in vivo environment, we designed a new microfluidic system in which the simultaneous, independent cultures of two cell lines (non-malignant and cancer cells) and their one-step analysis were possible. We observed that the sequential combination of photodynamic therapy (PDT) with chemotherapy allowed to obtain the synergistic effect of the treatment with using low doses of drugs. We also confirmed that the use of microfluidic conditions significantly increased the effectiveness of combination therapy and allowed for maintaining a high selectivity of the action of drugs on cancer cells. To the best of our knowledge, for the first time the microfluidic system was used to carry out sequential combination therapy against ovarian cancer.

Supramolecular nanoscale drug-delivery system with ordered structure

Supramolecular chemistry provides a means to integrate multi-type molecules leading to a dynamic organization. The study of functional nanoscale drug-delivery systems based on supramolecular interactions is a recent trend. Much work has focused on the design of supramolecular building blocks and the engineering of supramolecular integration, with the goal of optimized delivery behavior and enhanced therapeutic effect. This review introduces recent advances in supramolecular designs of nanoscale drug delivery. Supramolecular affinity can act as a main driving force either in the self-assembly of carriers or in the loading of drugs. It is also possible to employ strong recognitions to achieve self-delivery of drugs. Due to dynamic controllable drug-release properties, the supramolecular nanoscale drug-delivery system provides a promising platform for precision medicine.

Charge Regulation of Self-Assembled Tubules by Protonation for Efficiently Selective and Controlled Drug Delivery

Despite the success for targeted delivery in the body, the efficient release without side effects caused by residual drug remains a challenge. For reducing residual drug, the pH-responsive carriers were prepared by self-assembly from aromatic macrocycles, which were non-toxic and biocompatible. The inner surroundings of aromatic macrocycles could be protonated positively by acid inducing the separation of neighboring macrocycles. Thus, Dox-loaded carriers successfully inhibited the proliferation of carcinoma cells (HepG2 and 4T1) rather than normal cells (HL7702). The effects were further proved in vivo without systemic cytotoxicity. Notably, the responsive environment for drug release depended on the concentration of carriers. Particularly, drug release was promoted by carrier separation. Carrier 2 exhibited preferable anticancer efficacy than carrier 1 due to the efficient release of Dox by full separation of the carrier. Collectively, we have developed a novel strategy serving as a selective and controlled drug release platform for cancer therapeutics.

Specific driving of the suicide E gene by the CEA promoter enhances the effects of paclitaxel in lung cancer

Classical chemotherapy for lung cancer needs new strategies to enhance its antitumor effect. The cytotoxicity, nonspecificity, and low bioavailability of paclitaxel (PTX) limits their use in this type of cancer. Suicide gene therapy using tumor-specific promoters may increase treatment effectiveness. We used carcinoembryonic antigen (CEA) as a tumor-specific promoter to drive the bacteriophage E gene (pCEA-E) towards lung cancer cells (A-549 human and LL2 mice cell lines) but not normal lung cells (L132 human embryonic lung cell line), in association with PTX as a combined treatment. The study was carried out using cell cultures, tumor spheroid models (MTS), subcutaneous induced tumors and lung cancer stem cells (CSCs). pCEA-E induced significant inhibition of A-549 and LL2 cell proliferation in comparison to L132 cells, which have lower CEA expression levels. Moreover, pCEA-E induced an important decrease in volume growth of A-549 and LL2 MTS producing intense apoptosis, in comparison to L132 MTS. In addition, pCEA-E enhanced the antitumor effects of PTX when combined, showing a synergistic effect. This effect was also observed in A-549 CSCs, which have been related to the recurrence of cancer. The in vivo study corroborated the effectiveness of the pCEA-E-PTX combined therapy, inducing a greater decrease in tumor volume compared to PTX and pCEA-E alone. Our results suggest that the CEA promoter is an excellent candidate for directing E gene expression specifically towards lung cancer cells, and may be used to enhance the effectiveness of PTX against this type of tumor.

Tangeretin-Assisted Platinum Nanoparticles Enhance the Apoptotic Properties of Doxorubicin: Combination Therapy for Osteosarcoma Treatment

Osteosarcoma (OS) is the most common type of cancer and the most frequent malignant bone tumor in childhood and adolescence. Nanomedicine has become an indispensable field in biomedical and clinical research, with nanoparticles (NPs) promising to increase the therapeutic efficacy of anticancer drugs. Doxorubicin (DOX) is a commonly used chemotherapeutic drug against OS; however, it causes severe side effects that restrict its clinical applications. Here, we investigated whether combining platinum NPs (PtNPs) and DOX could increase their anticancer activity in human bone OS epithelial cells (U2OS). PtNPs with nontoxic, effective, thermally stable, and thermoplasmonic properties were synthesized and characterized using tangeretin. We examined the combined effects of PtNPs and DOX on cell viability, proliferation, and morphology, reactive oxygen species (ROS) generation, lipid peroxidation, nitric oxide, protein carbonyl content, antioxidants, mitochondrial membrane potential (MMP), adenosine tri phosphate (ATP) level, apoptotic and antiapoptotic gene expression, oxidative stress-induced DNA damage, and DNA repair genes. PtNPs and DOX significantly inhibited U2OS viability and proliferation in a dose-dependent manner, increasing lactate dehydrogenase leakage, ROS generation, and malondialdehyde, nitric oxide, and carbonylated protein levels. Mitochondrial dysfunction was confirmed by reduced MMP, decreased ATP levels, and upregulated apoptotic/downregulated antiapoptotic gene expression. Oxidative stress was a major cause of cytotoxicity and genotoxicity, confirmed by decreased levels of various antioxidants. Furthermore, PtNPs and DOX increased 8-oxo-dG and 8-oxo-G levels and induced DNA damage and repair gene expression. Combination of cisplatin and DOX potentially induce apoptosis comparable to PtNPs and DOX. To the best of our knowledge, this is the first report to describe the combined effects of PtNPs and DOX in OS.

In Vitro and In Vivo Co-delivery of siRNA and Doxorubicin by Folate-PEG-Appended Dendrimer/Glucuronylglucosyl-β-Cyclodextrin Conjugate

We have previously reported the utility of folate-polyethylene glycol-appended dendrimer conjugate with glucuronylglucosyl-β-cyclodextrin (Fol-PEG-GUG-β-CDE) (generation 3) as a tumor-selective carrier for siRNA against polo-like kinase 1 (siPLK1) in vitro. In the present study, we evaluated the potential of Fol-PEG-GUG-β-CDE as a carrier for the low-molecular antitumor drug doxorubicin (DOX). Further, to fabricate advanced antitumor agents, we have prepared a ternary complex of Fol-PEG-GUG-β-CDE/DOX/siPLK1 and evaluated its antitumor activity both in vitro and in vivo. Fol-PEG-GUG-β-CDE released DOX in an acidic pH and enhanced the cellular accumulation and cytotoxic activity of DOX in folate receptor-α (FR-α)-overexpressing KB cells. Importantly, the Fol-PEG-GUG-β-CDE/DOX/siPLK1 ternary complex exhibited higher cytotoxic activity than a binary complex of Fol-PEG-GUG-β-CDE with DOX or siPLK1 in KB cells. In addition, the cytotoxic activity of the ternary complex was reduced by the addition of folic acid, a competitor against FR-α. Furthermore, the ternary complex showed a significant antitumor activity after intravenous administration to the tumor-bearing mice. These results suggest that Fol-PEG-GUG-β-CDE has the potential of a tumor-selective co-delivery carrier for DOX and siPLK1.

A Polycationic Brush Mediated Co-Delivery of Doxorubicin and Gene for Combination Therapy

The combination of drug and gene strategies for cancer therapy, has exhibited greater effectiveness than drug or gene therapy alone. In this paper, a coil-comb shaped polycationic brush was used as a multifunctional carrier for co-delivery of drug and gene. The side chains of the comb block of the brush were composed of cyclodextrin (CD)-containing cationic star polymers, with a super-high density of positive charge. Doxorubicin (DOX) could be loaded into the cavity of CD polymers to form DOX-loaded nanoparticles (DOX-NPs) and the p53 gene could be subsequently condensed by DOX-NPs. The obtained DOX-NPs/pDNA complexes were less than 150 nm in size, and so could transport DOX and the gene into the same cell. The complexes performed well with regards to their transfection efficiency on MCF-7 cancer cells. As a result, enhanced cell growth inhibition, with decreased DOX dosage was achieved due to the synergistic effect of co-delivery of DOX and the p53 gene. This finding provides an efficient approach for the development of a co-delivery system in combination therapy.

Nanotechnology for Cancer Therapy Based on Chemotherapy

Chemotherapy has been widely applied in clinics. However, the therapeutic potential of chemotherapy against cancer is seriously dissatisfactory due to the nonspecific drug distribution, multidrug resistance (MDR) and the heterogeneity of cancer. Therefore, combinational therapy based on chemotherapy mediated by nanotechnology, has been the trend in clinical research at present, which can result in a remarkably increased therapeutic efficiency with few side effects to normal tissues. Moreover, to achieve the accurate pre-diagnosis and real-time monitoring for tumor, the research of nano-theranostics, which integrates diagnosis with treatment process, is a promising field in cancer treatment. In this review, the recent studies on combinational therapy based on chemotherapy will be systematically discussed. Furthermore, as a current trend in cancer treatment, advance in theranostic nanoparticles based on chemotherapy will be exemplified briefly. Finally, the present challenges and improvement tips will be presented in combination therapy and nano-theranostics.

Co-Delivery of Drugs and Genes Using Polymeric Nanoparticles for Synergistic Cancer Therapeutic Effects

Drug and gene delivery systems based on nanoparticles, microparticles and hydrogels have been widely studied for cancer treatment in the past decade. To achieve an efficient and safe delivery, selection of drug and gene delivery carrier is critical. Biocompatible polymeric nanoparticles are considerably promising carrier candidates in delivery of drugs and genes because of their unique chemical and physical properties. However, delivery of a drug or gene sometimes cannot achieve a satisfactory treatment effect. Therefore, co-delivery of dual drugs or co-delivery of a drug and a gene in a polymeric nanoparticle has attracted attention. Such co-delivery systems can overcome multi-drug resistance of chemical drugs and achieve a synergistic therapeutic effect. In this progress report, we summarize recent progress in the preparation and application of polymeric drug and gene co-delivery nanosystems. The remaining challenges and future trends in this field are also included.

A synergistic polyphosphoester-based co-delivery system of the anticancer drug doxorubicin and the tumor suppressor gene p53 for lung cancer therapy

Hybrid micelles composed of polymeric prodrug and gene carrier were constructed by polyphosphoester-based co-delivery system for lung cancer therapy.

A "protective umbrella" nanoplatform for loading ICG and multi-modal imaging-guided phototherapy

In order to prevent the aggregation of ICG and enhance its stability, a novel nanoplatform (TiO₂:Yb,Ho,F-β-CD@ICG/HA) was designed for NIR-induced phototherapy along with multi-mode imaging(UCL/MRI/Flu). In this nanosysytem: TiO₂:Yb,Ho,F was used as upconversion materials and applied in vivo for the first time; β-CD acted as a "protective umbrella" to load separated ICG and avoid the low phototherapy efficiency because of its aggregation; HA was the capping agent of β-CD to prevent ICG unexpected leaking and a target to recognize CD44 receptor. The nanosystem exhibited excellent size (~200 nm) and photo- and thermal-stability, preferable reactive oxygen yield and temperature response (50.4 °C) under 808 nm laser. It could efficiently target and suppress tumor growth. The imaging ability (UCL/MRI) of TiO₂:Yb,Ho,F could facilitate diagnosis of the tumor, especially for deep tissues. Altogether, our work successfully improved the phototherapy efficacy through incorporating the ICG into the cavity of β-CD and applied TiO₂:Yb,Ho,F for upconversion imaging in vivo.