An artificial cell system for biocompatible gene delivery in cancer therapy

Engineering Self-Assembled Nanomedicines Composed of Clinically Approved Medicines for Enhanced Tumor Nanotherapy

The traditional nanocarriers are typically constructed to deliver anticancer agents for improving drug bioavailability and enhancing chemotherapeutic efficacy, but this strategy suffers from the critical issue of nanocarrier biosafety that hinders further clinical translation. In this work, a unique nanomedicine (PTX@ICG) has been rationally constructed by combining two clinically approved agents, i.e., paclitaxel (PTX) and indocyanine green (ICG), by a facile ultrasound-assisted self-assembly methodology. The formation of the nanostructure can effectively increase the enrichment of PTX and ICG molecules in the tumor site, and improve the utilization factor of hydrophobic PTX. Moreover, since the molecule interaction in PTX@ICG is mainly Van der Waals forces, the self-assembled structure can be spontaneously dissociated under laser irradiation and release PTX in situ to achieve safe tumor-targeted chemotherapy. Simultaneously, the released ICG can act as photothermic agents for photothermal therapy (PTT), thus combining chemotherapy and PTT to obtain an enhanced tumor nanotherapy via facile self-assembly. The synergistic chemo/photothermal tumor nanotherapy achieved the efficient tumor cell-killing effect and tumor-ablation ability, as systematically demonstrated both in vitro and in vivo. This work provides a distinct paradigm of the self-assembled nanomedicine design for effectively improving the drug bioavailability to achieve high antitumor efficacy.

Cancer Exosome Loaded with Paclitaxel for Targeted Lung Cancer Therapy

Lung cancer is a serious issue to threat the health of human and the treatment using currently available chemotherapy drug, such as paclitaxel (PTX) is significantly impaired by the poor solubility and targetability. In this study, we used the cancer exosome (CE) derived from lung cancer cell line A549 to load PTX (CE/PTX) and construct a drug delivery system (DDS) for the treatment of A549 tumor in a mice mode. The DDS realized better inhibition on both A549 cells and tumors as compared to commercial PTX formulation (Taxol). Therefore, we believe this strategy can be applied to clinical trials for better cancer treatment.

Artificial cell design: reconstructing biology for life science applications

Artificial cells are developed to redesign novel biological functions in a programmable and tunable manner. Although it aims to reconstitute living cell features and address 'origin of life' related questions, rapid development over the years has transformed artificial cells into an engineering tool with huge potential in applied biotechnology. Although the application of artificial cells was introduced decades ago as drug carriers, applications in other sectors are relatively new and could become possible with the technological advancement that can modulate its designing principles. Artificial cells are non-living system that includes no prerequisite designing modules for their formation and therefore allow freedom of assembling desired biological machinery within a physical boundary devoid of complex contemporary living-cell counterparts. As stimuli-responsive biomimetic tools, artificial cells are programmed to sense the surrounding, recognise their target, activate its function and perform the defined task. With the advantage of their customised design, artificial cells are being studied in biosensing, drug delivery, anti-cancer therapeutics or artificial photosynthesis type fields. This mini-review highlights those advanced fields where artificial cells with a minimalistic setup are developed as user-defined custom-made microreactors, targeting to reshape our future 'life'.

Artificial Cells: Past, Present and Future

Artificial cells are constructed to imitate natural cells and allow researchers to explore biological process and the origin of life. The construction methods for artificial cells, through both top-down or bottom-up approaches, have achieved great progress over the past decades. Here we present a comprehensive overview on the development of artificial cells and their properties and applications. Artificial cells are derived from lipids, polymers, lipid/polymer hybrids, natural cell membranes, colloidosome, metal-organic frameworks and coacervates. They can be endowed with various functions through the incorporation of proteins and genes on the cell surface or encapsulated inside of the cells. These modulations determine the properties of artificial cells, including producing energy, cell growth, morphology change, division, transmembrane transport, environmental response, motility and chemotaxis. Multiple applications of these artificial cells are discussed here with a focus on therapeutic applications. Artificial cells are used as carriers for materials and information exchange and have been shown to function as targeted delivery systems of personalized drugs. Additionally, artificial cells can function to substitute for cells with impaired function. Enzyme therapy and immunotherapy using artificial cells have been an intense focus of research. Finally, prospects of future development of cell-mimic properties and broader applications are highlighted.

Recent advances in surface modification of micro- and nano-scale biomaterials with biological membranes and biomolecules

Surface modification of biomaterial can improve its biocompatibility and add new biofunctions, such as targeting specific tissues, communication with cells, and modulation of intracellular trafficking. Here, we summarize the use of various natural materials, namely, cell membrane, exosomes, proteins, peptides, lipids, fatty acids, and polysaccharides as coating materials on micron- and nano-sized particles and droplets with the functions imparted by coating with different materials. We discuss the applicability, operational parameters, and limitation of different coating techniques, from the more conventional approaches such as extrusion and sonication to the latest innovation seen on the microfluidics platform. Methods commonly used in the field to examine the coating, including its composition, physical dimension, stability, fluidity, permeability, and biological functions, are reviewed.

Spatial confinement toward creating artificial living systems

Lifeforms are regulated by many physicochemical factors, and these factors could be controlled to play a role in the construction of artificial living systems. Among these factors, spatial confinement is an important one, which mediates biological behaviors at multiscale levels and participates in the biomanufacturing processes accordingly. This review describes how spatial confinement, as a fundamental biological phenomenon, provides cues for the construction of artificial living systems. Current knowledge about the role of spatial confinement in mediating individual cell behavior, collective cellular behavior, and tissue-level behavior are categorized. Endeavors on the synthesis of biomacromolecules, artificial cells, engineered tissues, and organoids in spatially confined bioreactors are then emphasized. After that, we discuss the cutting-edge applications of spatially confined artificial living systems in biomedical fields. Finally, we conclude by assessing the remaining challenges and future trends in the context of fundamental science, technical improvement, and practical applications.

Facile Preparation of Paclitaxel Nano-Suspensions to Treat Lung Cancer

Lung cancer is a worldwide issue which account for the death of thousands every year. Paclitaxel (PTX) as the first line chemotherapy drug to treat lung cancer, its clinical applications is largely limited by its poor solubility. The facile preparation of pharmaceutical formulations to increase the solubility as well as targetability of PTX is of vital importance in lung cancer treatment. Herein, we introduced a facile method to prepare PTX nano-suspensions (NSs), which have high drug loading as well as well-dispersed particle size. The in vitro cell experiments revealed its capability to enhance the drug accumulation in A549 cells than free PTX. Moreover, in vivo animal assay suggested its better tumor accumulation and antitumor efficacy than PTX injection (Taxol).

Manganese dioxide nanozyme for reactive oxygen therapy of bacterial infection and wound healing

Reactive oxygen species (ROS) are the weapons of neutrophiles against bacterial pathogens, and also the central effectors in reactive oxygen therapy for skin and soft tissue infection. Nanozymes that spontaneously generate ROS under physiological conditions are new antibacterials that hold promise towards multidrug resistant pathogens. The clinical use of the nanozymes is however limited by their low biocompatibility and toxicity in vivo. Here, we develop an oleic acid (OA) nanoemulsion template method for the one-pot synthesis of OA-manganese dioxide (MnO₂) nanozyme. The OA-MnO₂ nanozyme showed high stability and biocompatibility under physiological conditions with marked oxidase-like activity. The ROS generated by the OA-MnO₂ nanozyme effectively kill the Gram-positive Staphylococcus aureus and the Gram-negative Escherichia coli strains. Moreover, the OA-MnO₂ nanozyme shows promising abilities to prevent and destruct biofilm formation by Staphylococcus aureus, and result in superior in vivo antibacterial performance as compared to vancomycin. The reactive oxygen therapy based on OA-MnO₂ nanozyme cures the infected skin and promotes wound healing in mice, manifesting its potential use in skin and soft tissue infection.

A Fluorescent Self-Reporting Vector with GSH Reduction Responsiveness for Nucleic Acid Delivery

Nonviral gene vectors with stimulus responsiveness and self-reporting properties have broad application prospects in gene therapy. Herein, we developed a nanosized reduction-responsive cationic liposomal vector formed from DNS(Zn), in which a naphthalimide-sulfonamide group was used as the glutathione (GSH)-responsive group to generate a blue fluorescence signal at 458 nm. Macrocyclic polyamine (cyclen) was used as a cationic headgroup to facilitate Zn(II) coordination, which may reduce the cytotoxicity and improve transfection efficiency. The Zn-free and nonresponsive analogues were used for comparison. Fluorescent assays revealed that the GSH response of DNS(Zn) could increase the blue fluorescence signal and improve the DNA release in cells. The title material also showed higher positive ζ-potential than its nonresponsive analogue, resulting in stronger DNA binding ability and better cellular uptake. These advantages made DNS(Zn) a good candidate for nonviral gene delivery, and the transfection efficiency in HeLa cells was distinctly higher than that of its analogue and the commercially available transfection reagent. Besides plasmid DNA, DNS(Zn) could also deliver small interfering RNA (siRNA) with good gene silencing efficiency, extending the application of the liposomes. These results suggest that DNS(Zn) can serve as a highly efficient nucleic acid delivery vector with reduction-responsive fluorescence self-reporting ability in tumor cells.

Autophagy Modulation and Synergistic Therapy to Combat Multidrug Resistance Breast Cancer Using Hybrid Cell Membrane Nanoparticles

The development of multidrug resistance (MDR) is a commonly observed phenomenon in many cancer types. It contributed significantly to the poor outcome of many currently available chemotherapies. Considering autophagy as one of the most important physiological process in cancer progression, we thereby proposed an anti-autophagy siRNA and doxorubicin (Dox) co-delivery system (MC/D-siR) to combat MDR breast cancer using sequential construction. Our results demonstrated the potential of MC/D-siR to effectively transfect the loaded siRNA to result in significant downregulation of intracellular autophagy level in MCF-7/Adr (Dox resistance MCF-7 cell line) cells, which in turn cut off the ATP supply and to reverse the MDR and potentiated accumulated drug retention in cells. As a result, MC/D-siR showed much elevated anticancer benefits than single loaded platforms (MC/Dox or MC/siRNA), indicating the ability for effective MDR cancer treatment through the combination of autophagy regulation and chemotherapy.

Co-delivery of cisplatin and oleanolic acid by silica nanoparticles-enhanced apoptosis and reverse multidrug resistance in lung cancer

Multidrug resistance (MDR) of chemotherapy is one of the significant concerns in cancer therapy. Here in our study, cisplatin (DDP) and oleanolic acid (OA) were co-loaded in mesoporous silica nanoparticles (Nsi) to construct DDP/OA-Nsi and solve the DDP-resistance in lung cancer therapy. The cytotoxicity and apoptosis assays demonstrated that in DDP-resistant A549/DDP cells, the cytotoxicity of DDP/OA-Nsi was significantly higher than that of free DDP or DDP single delivery system (DDP-Nsi). The intracellular drug accumulation study revealed that the intracellular DDP concentration in the DDP/OA-Nsi group was also higher than that in free DDP and DDP-Nsi groups. In the A549/DDP xenograft tumor model, DDP/OA-Nsi showed the best anticancer effect. In summary, DDP/OA-Nsi was a promising drug delivery system to solve MDR in lung cancer therapy.

Red Blood Cell Membrane-Coated Silica Nanoparticles Codelivering DOX and ICG for Effective Lung Cancer Therapy

The effective chemotherapy of cancer is usually hindered by the unsatisfied cell internalization of the drug delivery systems (DDS) as well as drug resistance of cancer cells. In order to solve these dilemmas in one design, red blood cell membrane (RBM)-coated silica nanoparticles (RS) were fabricated to codeliver doxorubicin (Dox) and indocyanine green (ICG) to effectively treat the model lung cancer using photothermal-assisted chemotherapy. Our results demonstrated that the RS/I-D was the nanoparticle at around 100 nm with superior stability and biocompatibility. Especially, the photothermal effects of ICG were well preserved and could be applied to accelerate the drug release from the DDS. More importantly, the RBM modification can mediate enhanced cell internalization of drugs as compared to their free forms, which finally resulted in enhanced anticancer efficacy in Dox-resistant A549 cells (A549/Dox) both in vitro and in vivo with enhanced cell apoptosis and cell arrest.

Chondroitin sulfate modified and adriamycin preloaded hybrid nanoparticles for tumor-targeted chemotherapy of lung cancer

Promising cancer treatment requires the assistant of drug delivery systems (DDS) with the aim to increase the accumulation of drugs in tumor tissue. Herein, a hybrid DDS was successfully developed to integrate chondroitin sulfate (CS) and calcium carbonate (CC) in to one system. Anticancer drug adriamycin (Adr) was preloaded into CC nanoparticles to obtain Adr-loaded CC nanoparticles (CC/Adr). The resulted CS-CC/Adr nanoparticles as a biocompatible DDS was able to specifically target cancer cells to enhance the chemotherapy of lung cancer due to the surface modification of CS. Intracellular uptake as well as in vivo imaging results revealed the obtained CS-CC/Adr nanoparticles (size of ~100 nm) showed CS mediated tumor specific accumulation into A549 and LLC cells than unmodified CC/Adr, in which the CD44 receptor might be involved, which finally resulted in stronger anticancer capability than Adr or CC/Adr. As a result, CS-CC/Adr nanoparticles could be further extended to clinical administration in our future works.

Nanostructured Lipid Carriers Delivering Sorafenib to Enhance Immunotherapy Induced by Doxorubicin for Effective Esophagus Cancer Therapy

The tumor microenvironment (TME) plays a significant role in weakening the effect of cancer immunotherapy, which calls for the remodeling of TME. Herein, we fabricated a nanostructured lipid carrier (NLC) to codeliver doxorubicin (Dox) and sorafenib (Sfn) as a drug delivery system (NLC/D-S). The Sfn was expected to regulate the TME of esophagus cancer. As a result, the immune response induced by Dox-related immunogenicity cell death could be fully realized. Our results demonstrated that Sfn was able to remodel the TME through downregulation of regulatory T cells (Treg), activation of effector T cells, and relieving of PD-1 expression, which achieved synergistic effect on the inhibition of primary tumor but also subsequent strong immune response on the regeneration of distant tumor.

A cell membrane vehicle co-delivering sorafenib and doxorubicin remodel the tumor microenvironment and enhance immunotherapy by inducing immunogenic cell death in lung cancer cells

Cancer immunotherapy is a promising approach for cancer therapy but is usually hindered by the inhibition of the tumor microenvironment (TME). Herein, we developed a cell membrane vehicle (CV) to co-deliver doxorubicin (Dox) and sorafenib (Sfn) as a drug delivery system (CV/D-S) to regulate the TME and sensitize the immunogenic cell death (ICD)-induced immune response against tumors. The CV/D-S showed high stability, acid-responsive drug release, high biocompatibility with tumor-specific cellular uptake, and target-ability that preferably resulted in the in vitro and in vivo anticancer performance. Most importantly, the Dox in the DDS can induce significant ICD while Sfn was able to remodel the TME, downregulate Treg, activate effector T cells and relieve programmed cell death protein 1 (PD-1) expression. As a result, the synergistic effect of Dox and Sfn achieved strong immune response in CV/D-S treated mice, which is believed to open a new window for the design and development of future platforms for the more effective immunotherapy of cancer.

Mirror siRNAs loading for dual delivery of doxorubicin and autophagy regulation siRNA for multidrug reversing chemotherapy

The multidrug resistance (MDR) which widely observed in multiple cancer types is responsible for the poor chemotherapy benefits of doxorubicin (Dox). Here in our study, Dox was firstly loaded into a scramble siRNA and then condensed by polyethyleneimine (PEI) 25k together with anti-autophagy siRNA, the obtained PEI/Si-D containing mirror RNAs was further coated with hyaluronic acid (HA) to shield the surface charge of PEI and offer tumor-homing property that finally developed a platform for effective cancer chemotherapy (HP/Si-D). Our results revealed that the obtained HP/Si-D was showed high stability and biocompatibility with promising transfection profile. As a result, the anti-autophagy siRNA downregulated autophagy level of target cells, which further decreased ATP supply to enhance drug retention and cell cycle arrest. These results contributed significantly to reverse the MDR of A549/Dox (Dox resistance A549 cell line) cells with promising in vitro and in vivo results, which suggested the potential of effective MDR cancer therapy using synergistic anti-autophagy and chemotherapy.