Cancer cell membrane cloaking nanoparticles for targeted co-delivery of doxorubicin and PD-L1 siRNA

Advancing cancer treatments: The role of oligonucleotide-based therapies in driving progress

Although recent advancements in cancer immunology have resulted in the approval of numerous immunotherapies, minimal progress has been observed in addressing hard-to-treat cancers. In this context, therapeutic oligonucleotides, including interfering RNAs, antisense oligonucleotides, aptamers, and DNAzymes, have gained a central role in cancer therapeutic approaches due to their capacity to regulate gene expression and protein function with reduced toxicity compared with conventional chemotherapeutics. Nevertheless, systemic administration of naked oligonucleotides faces many extra- and intracellular challenges that can be overcome by using effective delivery systems. Thus, viral and non-viral carriers can improve oligonucleotide stability and intracellular uptake, enhance tumor accumulation, and increase the probability of endosomal escape while minimizing other adverse effects. Therefore, gaining more insight into fundamental mechanisms of actions of various oligonucleotides and the challenges posed by naked oligonucleotide administration, this article provides a comprehensive review of the recent progress on oligonucleotide delivery systems and an overview of completed and ongoing cancer clinical trials that can shape future oncological treatments.

Chitosan-based smart stimuli-responsive nanoparticles for gene delivery and gene therapy: Recent progresses on cancer therapy

Recent cancer therapy research has found that chitosan (Ch)-based nanoparticles show great potential for targeted gene delivery. Chitosan, a biocompatible and biodegradable polymer, has exceptional properties, making it an ideal carrier for therapeutic genes. These nanoparticles can respond to specific stimuli like pH, temperature, and enzymes, enabling precise delivery and regulated release of genes. In cancer therapy, these nanoparticles have proven effective in delivering genes to tumor cells, slowing tumor growth. Adjusting the nanoparticle's surface, encapsulating protective agents, and using targeting ligands have also improved gene delivery efficiency. Smart nanoparticles based on chitosan have shown promise in improving outcomes by selectively releasing genes in response to tumor conditions, enhancing targeted delivery, and reducing off-target effects. Additionally, targeting ligands on the nanoparticles' surface increases uptake and effectiveness. Although further investigation is needed to optimize the structure and composition of these nanoparticles and assess their long-term safety, these advancements pave the way for innovative gene-focused cancer therapies.

Robust aptamer-targeted CRISPR/Cas9 delivery using mesenchymal stem cell membrane -liposome hybrid: BIRC5 gene knockout against melanoma

In this study, a platform was fabricated by combining a cationic lipid, 1,2-Dioleoyl-3-trimethylammonium-propane (DOTAP) with mesenchymal stem cell membrane (MSCM) to produce a positively charged hybrid vesicle. The prepared hybrid vesicle was used to condense BIRC5 CRISPR/Cas9 plasmid for survivin (BIRC5) gene editing. The Sgc8-c aptamer (against protein tyrosine kinase 7) was then attached to the surface of the prepared NPs through electrostatic interactions. In this regard, melanoma cancer cells (B16F0 cell line) overexpressing PTK7 receptor could be targeted. Investigations were conducted on this system to evaluate its transfection efficiency, cellular toxicity, and therapeutic performance in preclinical stage using B16F0 tumor bearing C57BL/6 J mice. The results verified the superiority of the Hybrid/ BIRC5 compared to Liposome/ BIRC5 in terms of cellular toxicity and transfection efficiency. The cells exposure to Hybrid/BIRC5 significantly enhanced cytotoxicity. Moreover, cells treated with Apt-Hybrid/BIRC5 showed higher anti-proliferation activity toward PTK7-positive B16F0 cancer cells than that of the PKT7-negative CHO cell line. The active tumor targeting nanoparticles increased the cytotoxicity through down-regulation of BIRC5 expression as confirmed by Western blot analysis. In preclinical stage, Apt-Hybrid/BIRC5 showed remarkable tumor growth suppression toward B16F0 tumorized mice. Thus, our study suggested that genome editing for BIRC5 through the CRISPR/Cas9 system could provide a potentially safe approach for melanoma cancer therapy and has great potential for clinical translation.

Biomimetic Nucleic Acid Drug Delivery Systems for Relieving Tumor Immunosuppressive Microenvironment

Immunotherapy combats tumors by enhancing the body's immune surveillance and clearance of tumor cells. Various nucleic acid drugs can be used in immunotherapy, such as DNA expressing cytokines, mRNA tumor vaccines, small interfering RNAs (siRNA) knocking down immunosuppressive molecules, and oligonucleotides that can be used as immune adjuvants. Nucleic acid drugs, which are prone to nuclease degradation in the circulation and find it difficult to enter the target cells, typically necessitate developing appropriate vectors for effective in vivo delivery. Biomimetic drug delivery systems, derived from viruses, bacteria, and cells, can protect the cargos from degradation and clearance, and deliver them to the target cells to ensure safety. Moreover, they can activate the immune system through their endogenous activities and active components, thereby improving the efficacy of antitumor immunotherapeutic nucleic acid drugs. In this review, biomimetic nucleic acid delivery systems for relieving a tumor immunosuppressive microenvironment are introduced. Their immune activation mechanisms, including upregulating the proinflammatory cytokines, serving as tumor vaccines, inhibiting immune checkpoints, and modulating intratumoral immune cells, are elaborated. The advantages and disadvantages, as well as possible directions for their clinical translation, are summarized at last.

Advances in biomimetic nanomaterial delivery systems: harnessing nature's inspiration for targeted drug delivery

The properties of nanomaterials make them promising and advantageous for use in drug delivery systems, but challenges arise from the immune system's recognition of exogenous nanoparticles, leading to their clearance and reduced targeting efficiency. Drawing inspiration from nature, this paper explores biomimetic strategies to transform recognizable nanomaterials into a "camouflaged state." The focal point of this paper is the exploration of bionic nanoparticles, with a focus on cell membrane-coated nanoparticles. These biomimetic structures, particularly those mimicking red blood cells (RBCs), white blood cells (WBCs), platelets, and cancer cells, demonstrate enhanced drug delivery efficiency and prolonged circulation. This article underscores the versatility of these biomimetic structures across diverse diseases and explores the use of hybrid cell membrane-coated nanoparticles as a contemporary trend. This review also investigated exosomes and protein bionic nanoparticles, emphasizing their potential for specific targeting, immune evasion, and improved therapeutic outcomes. We expect that this continued development based on biomimetic nanomaterials will contribute to the efficiency and safety of disease treatment.

Recent progress in biomimetic nanomedicines based on versatile targeting strategy for atherosclerosis therapy

Atherosclerosis (AS) is considered to be one of the major causes of cardiovascular disease. Its pathological microenvironment is characterised by increased production of reactive oxygen species, lipid oxides, and excessive inflammatory factors, which accumulate at the monolayer endothelial cells in the vascular wall to form AS plaques. Therefore, intervention in the pathological microenvironment would be beneficial in delaying AS. Researchers have designed biomimetic nanomedicines with excellent biocompatibility and the ability to avoid being cleared by the immune system through different therapeutic strategies to achieve better therapeutic effects for the characteristics of AS. Biomimetic nanomedicines can further enhance delivery efficiency and improve treatment efficacy due to their good biocompatibility and ability to evade clearance by the immune system. Biomimetic nanomedicines based on therapeutic strategies such as neutralising inflammatory factors, ROS scavengers, lipid clearance and integration of diagnosis and treatment are versatile approaches for effective treatment of AS. The review firstly summarises the targeting therapeutic strategy of biomimetic nanomedicine for AS in recent 5 years. Biomimetic nanomedicines using cell membranes, proteins, and extracellular vesicles as carriers have been developed for AS.

Advancing cancer immunotherapy through siRNA-based gene silencing for immune checkpoint blockade

Cancer immunotherapy represents a revolutionary strategy, leveraging the patient's immune system to inhibit tumor growth and alleviate the immunosuppressive effects of the tumor microenvironment (TME). The recent emergence of immune checkpoint blockade (ICB) therapies, particularly following the first approval of cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) inhibitors like ipilimumab, has led to significant growth in cancer immunotherapy. The extensive explorations on diverse immune checkpoint antibodies have broadened the therapeutic scope for various malignancies. However, the clinical response to these antibody-based ICB therapies remains limited, with less than 15% responsiveness and notable adverse effects in some patients. This review introduces the emerging strategies to overcome current limitations of antibody-based ICB therapies, mainly focusing on the development of small interfering ribonucleic acid (siRNA)-based ICB therapies and innovative delivery systems. We firstly highlight the diverse target immune checkpoint genes for siRNA-based ICB therapies, incorporating silencing of multiple genes to boost anti-tumor immune responses. Subsequently, we discuss improvements in siRNA delivery systems, enhanced by various nanocarriers, aimed at overcoming siRNA's clinical challenges such as vulnerability to enzymatic degradation, inadequate pharmacokinetics, and possible unintended target interactions. Additionally, the review presents various combination therapies that integrate chemotherapy, phototherapy, stimulatory checkpoints, ICB antibodies, and cancer vaccines. The important point is that when used in combination with siRNA-based ICB therapy, the synergistic effect of traditional therapies is strengthened, improving host immune surveillance and therapeutic outcomes. Conclusively, we discuss the insights into innovative and effective cancer immunotherapeutic strategies based on RNA interference (RNAi) technology utilizing siRNA and nanocarriers as a novel approach in ICB cancer immunotherapy.

Nanomaterials in Drug Delivery: Strengths and Opportunities in Medicine

There is a myriad of diseases that plague the world ranging from infectious, cancer and other chronic diseases with varying interventions. However, the dynamism of causative agents of infectious diseases and incessant mutations accompanying other forms of chronic diseases like cancer, have worsened the treatment outcomes. These factors often lead to treatment failure via different drug resistance mechanisms. More so, the cost of developing newer drugs is huge. This underscores the need for a paradigm shift in the drug delivery approach in order to achieve desired treatment outcomes. There is intensified research in nanomedicine, which has shown promises in improving the therapeutic outcome of drugs at preclinical stages with increased efficacy and reduced toxicity. Regardless of the huge benefits of nanotechnology in drug delivery, challenges such as regulatory approval, scalability, cost implication and potential toxicity must be addressed via streamlining of regulatory hurdles and increased research funding. In conclusion, the idea of nanotechnology in drug delivery holds immense promise for optimizing therapeutic outcomes. This work presents opportunities to revolutionize treatment strategies, providing expert opinions on translating the huge amount of research in nanomedicine into clinical benefits for patients with resistant infections and cancer.

Application and advances of biomimetic membrane materials in central nervous system disorders

Central nervous system (CNS) diseases encompass spinal cord injuries, brain tumors, neurodegenerative diseases, and ischemic strokes. Recently, there has been a growing global recognition of CNS disorders as a leading cause of disability and death in humans and the second most common cause of death worldwide. The global burdens and treatment challenges posed by CNS disorders are particularly significant in the context of a rapidly expanding global population and aging demographics. The blood-brain barrier (BBB) presents a challenge for effective drug delivery in CNS disorders, as conventional drugs often have limited penetration into the brain. Advances in biomimetic membrane nanomaterials technology have shown promise in enhancing drug delivery for various CNS disorders, leveraging properties such as natural biological surfaces, high biocompatibility and biosafety. This review discusses recent developments in biomimetic membrane materials, summarizes the types and preparation methods of these materials, analyzes their applications in treating CNS injuries, and provides insights into the future prospects and limitations of biomimetic membrane materials.

Better together: nanoscale co-delivery systems of therapeutic agents for high-performance cancer therapy

Combination therapies can enhance the sensitivity of cancer to drugs, lower drug doses, and reduce side effects in cancer treatment. However, differences in the physicochemical properties and pharmacokinetics of different therapeutic agents limit their application. To avoid the above dilemma and achieve accurate control of the synergetic ratio, a nanoscale co-delivery system (NCDS) has emerged as a prospective tool for combined therapy in cancer treatment, which is increasingly being used to co-load different therapeutic agents. In this study, we have summarized the mechanisms of therapeutic agents in combination for cancer therapy, nanoscale carriers for co-delivery, drug-loading strategies, and controlled/targeted co-delivery systems, aiming to give a general picture of these powerful approaches for future NCDS research studies.

Cancer cell membrane-coated nanoparticles: a promising anti-tumor bionic platform

Nanoparticle (NP) drug delivery systems have shown promise in tumor therapy. However, limitations such as susceptibility to immune clearance and poor targeting in a complex intercellular environment still exist. Recently, cancer cell membrane-encapsulated nanoparticles (CCM-NPs) constructed using biomimetic nanotechnology have been developed to overcome these problems. Proteins on the membrane surface of cancer cells can provide a wide range of activities for CCM-NPs, including immune escape and homologous cell recognition properties. Meanwhile, the surface of the cancer cell membrane exhibits obvious antigen enrichment, so that CCM-NPs can transmit tumor-specific antigen, activate a downstream immune response, and produce an effective anti-tumor effect. In this review, we first provided an overview of the functions of cancer cell membranes and summarized the preparation techniques and characterization methods of CCM-NPs. Then, we focused on the application of CCM-NPs in tumor therapy. In addition, we summarized the functional modifications of cancer cell membranes and compiled the patent applications related to CCM-NPs in recent years. Finally, we proposed the future challenges and directions of this technology in order to provide guidance for researchers in this field.

Membrane-Cloaked Nanoparticles for RNA Interference of β-Catenin in Triple-Negative Breast Cancer

There is an outstanding need for targeted therapies for triple-negative breast cancer (TNBC), an aggressive breast cancer subtype. Since TNBC's rapid growth and metastasis are driven by hyperactive Wnt signaling, suppressing the key-pathway mediator β-catenin through RNA interference may improve patient outcomes. However, small interfering ribonucleic acid (siRNA) molecules require a carrier to elicit targeted gene silencing. Here, we show that 4T1 cancer cell membrane wrapped poly(lactic-co-glycolic acid) (PLGA) nanoparticles (NPs) can deliver siRNA into TNBC cells, silence β-catenin expression, and reduce the cells' tumorigenic qualities. Compared to unwrapped and nontargeted NPs, the cancer cell membrane wrapped nanoparticles (CCNPs) exhibit dramatically improved uptake by TNBC cells versus breast epithelial cells and greater gene silencing at mRNA and protein levels. Congruently, β-catenin siRNA-loaded CCNPs significantly activate senescence in 2D cultured TNBC cells and reduce proliferation in 3D spheroids. This work advances the development of nucleic acid carriers for targeted RNA interference therapy.

Cancer Cell Membrane-Based Materials for Biomedical Applications

The nanodelivery system provides a novel direction for disease diagnosis and treatment; however, its delivery effectiveness is restricted by the short biological half-life and inadequate tumor targeting. The immune evasion properties and homologous targeting capabilities of natural cell membranes, particularly those of cancer cell membranes (CCM), have gained significant interest. The integration of CCM and nanoparticles has resulted in the emergence of CCM-based nanoplatforms (CCM-NPs), which have gained significant attention due to their unique properties. CCM-NPs not only prolong the blood circulation time of core nanoparticles, but also direct them for homologous tumor targeting. Herein, the history and development of CCM-NPs as well as how these platforms have been used for biomedical applications are discussed. The application of CCM-NPs for cancer therapy will be described in detail. Translational efforts are currently under way and further research to address key areas of need will ultimately be required to facilitate the successful clinical adoption of CCM-NPs.

Cell Membrane-Camouflaged Nanoparticles Mediated Nucleic Acids Delivery

Nucleic acids have emerged as promising therapeutic agents for many diseases because of their potential in modulating gene expression. However, the delivery of nucleic acids remains a significant challenge in gene therapy. Although viral vectors have shown high transfection efficiency, concerns regarding teratogenicity or carcinogenicity have been raised. Non-viral vehicles, including cationic polymers, liposomes, and inorganic materials possess advantages in terms of safety, ease of preparation, and low cost. Nevertheless, they also face limitations related to immunogenicity, quick clearance in vivo, and lack of targeting specificity. On the other hand, bioinspired strategies have shown increasing potential in the field of drug delivery, yet there is a lack of comprehensive reviews summarizing the rapid development of bioinspired nanoparticles based on the cell membrane camouflage to construct the nucleic acids vehicles. Herein, we enumerated the current difficulties in nucleic acid delivery with various non-viral vehicles and provided an overview of bioinspired strategies for nucleic acid delivery.

Biomimetic theranostic nanoparticles for effective anticancer therapy and MRI imaging

Cancer remains a leading cause of mortality worldwide, necessitating the development of innovative therapeutic approaches. Nanoparticle-based drug delivery systems have garnered significant interest due to their multifunctionality, offering the potential to enhance cancer treatment efficacy and improve patient tolerability. Membrane-coated drug delivery systems hold great potential for enhancing the therapeutic outcome of nanoparticle-based anticancer therapies. In this study, we report the synthesis of multifunctional iron-functionalized mesoporous polydopamine nanoparticles (MPDAFe NPs). These nanoformulations demonstrate substantial potential for combining efficient drug delivery and magnetic resonance imaging (MRI) and showcase the advantages of biomimetic coating with tumor cell-derived membranes. This coating confers prolonged circulation and improved the targeting capabilities of the nanoparticles. Furthermore, comprehensive biosafety evaluations reveal negligible toxicity to normal cells, while the combined chemo- and phototherapy exhibited significant cytotoxicity towards cancer cells. Additionally, the photothermal effect evaluation highlights the enhanced cytotoxicity achieved through laser irradiation, showcasing the synergistic effects of the nanomaterials and photothermal therapy. Importantly, our chemotherapeutic effect evaluation demonstrates the superior efficacy of doxorubicin-loaded MPDAFe@Mem NPs (cancer cell membrane-coated MPDAFe NPs) in inhibiting cancer cell viability and proliferation, surpassing the potency of free doxorubicin. This study comprehensively investigates theranostic, membrane-coated drug delivery systems, underlining their potential to increase the efficacy of cancer treatment strategies. The multifunctional nature of the iron-functionalized polydopamine nanoparticles allows for efficient drug delivery and imaging capabilities, while the biomimetic coating enhances their biocompatibility and targeting ability. These findings contribute valuable insights towards the development of advanced nanomedicine for improved cancer therapeutics.

Multifunctional cell membranes-based nano-carriers for targeted therapies: a review of recent trends and future perspective

Nanotechnology has ignited a transformative revolution in disease detection, prevention, management, and treatment. Central to this paradigm shift is the innovative realm of cell membrane-based nanocarriers, a burgeoning class of biomimetic nanoparticles (NPs) that redefine the boundaries of biomedical applications. These remarkable nanocarriers, designed through a top-down approach, harness the intrinsic properties of cell-derived materials as their fundamental building blocks. Through shrouding themselves in natural cell membranes, these nanocarriers extend their circulation longevity and empower themselves to intricately navigate and modulate the multifaceted microenvironments associated with various diseases. This comprehensive review provides a panoramic view of recent breakthroughs in biomimetic nanomaterials, emphasizing their diverse applications in cancer treatment, cardiovascular therapy, viral infections, COVID-19 management, and autoimmune diseases. In this exposition, we deliver a concise yet illuminating overview of the distinctive properties underpinning biomimetic nanomaterials, elucidating their pivotal role in biomedical innovation. We subsequently delve into the exceptional advantages these nanomaterials offer, shedding light on the unique attributes that position them at the forefront of cutting-edge research. Moreover, we briefly explore the intricate synthesis processes employed in creating these biomimetic nanocarriers, shedding light on the methodologies that drive their development.

Advances in targeted therapy for pancreatic cancer

Pancreatic cancer (PC) represents a group of malignant tumours originating from pancreatic duct epithelial cells and acinar cells, and the 5-year survival rate of PC patients is only approximately 12%. Molecular targeted drugs are specific drugs designed to target and block oncogenes, and they have become promising strategies for the treatment of PC. Compared to traditional chemotherapy drugs, molecular targeted drugs have greater targeting precision, and they have significant therapeutic effects and minimal side effects. This article reviews several molecular targeted drugs that are currently in the experimental stage for the treatment of PC; these include antibody-drug conjugates (ADCs), aptamer-drug conjugates (ApDCs) and peptide-drug conjugates (PDCs). ADCs can specifically recognize cell surface antigens and reduce systemic exposure and toxicity of chemotherapy drugs. By delivering nucleic acid drugs to target cells, the targeting RNA of ApDCs can inhibit the expression or translation of mutated genes, thereby inhibiting tumour development. Moreover, PDCs can effectively penetrate tumour cells, and the peptide groups in PDCs preferentially target tumour cells with minimal side effects. In the targeted therapy of PC, molecular targeted drugs have very broad prospects, which provides new hope for the clinical treatment of PC patients and is worth further research.

Surface modification strategies in translocating nano-vesicles across different barriers and the role of bio-vesicles in improving anticancer therapy

Nanovesicles and bio-vesicles (BVs) have emerged as promising tools to achieve targeted cancer therapy due to their ability to overcome many of the key challenges currently being faced with conventional chemotherapy. These challenges include the diverse and often complex pathophysiology involving the progression of cancer, as well as the various biological barriers that circumvent therapeutic molecules reaching their target site in optimum concentration. The scientific evidence suggests that surface-functionalized nanovesicles and BVs camouflaged nano-carriers (NCs) both can bypass the established biological barriers and facilitate fourth-generation targeting for the improved regimen of treatment. In this review, we intend to emphasize the role of surface-functionalized nanovesicles and BVs camouflaged NCs through various approaches that lead to an improved internalization to achieve improved and targeted oncotherapy. We have explored various strategies that have been employed to surface-functionalize and biologically modify these vesicles, including the use of biomolecule functionalized target ligands such as peptides, antibodies, and aptamers, as well as the targeting of specific receptors on cancer cells. Further, the utility of BVs, which are made from the membranes of cells such as mesenchymal stem cells (MSCs), white blood cells (WBCs), red blood cells (RBCs), platelets (PLTs) as well as cancer cells also been investigated. Lastly, we have discussed the translational challenges and limitations that these NCs can encounter and still need to be overcome in order to fully realize the potential of nanovesicles and BVs for targeted cancer therapy. The fundamental challenges that currently prevent successful cancer therapy and the necessity of novel delivery systems are in the offing.

Nano-immunotherapy: overcoming delivery challenge of immune checkpoint therapy

Immune checkpoint (ICP) molecules expressed on tumor cells can suppress immune responses against tumors. ICP therapy promotes anti-tumor immune responses by targeting inhibitory and stimulatory pathways of immune cells like T cells and dendritic cells (DC). The investigation into the combination therapies through novel immune checkpoint inhibitors (ICIs) has been limited due to immune-related adverse events (irAEs), low response rate, and lack of optimal strategy for combinatorial cancer immunotherapy (IMT). Nanoparticles (NPs) have emerged as powerful tools to promote multidisciplinary cooperation. The feasibility and efficacy of targeted delivery of ICIs using NPs overcome the primary barrier, improve therapeutic efficacy, and provide a rationale for more clinical investigations. Likewise, NPs can conjugate or encapsulate ICIs, including antibodies, RNAs, and small molecule inhibitors. Therefore, combining the drug delivery system (DDS) with ICP therapy could provide a profitable immunotherapeutic strategy for cancer treatment. This article reviews the significant NPs with controlled DDS using current data from clinical and pre-clinical trials on mono- and combination IMT to overcome ICP therapeutic limitations.

Remodeling the tumor immune microenvironment via siRNA therapy for precision cancer treatment

How to effectively transform the pro-oncogenic tumor microenvironments (TME) surrounding a tumor into an anti-tumoral never fails to attract people to study. Small interfering RNA (siRNA) is considered one of the most noteworthy research directions that can regulate gene expression following a process known as RNA interference (RNAi). The research about siRNA delivery targeting tumor cells and TME has been on the rise in recent years. Using siRNA drugs to silence critical proteins in TME was one of the most efficient solutions. However, the manufacture of a siRNA delivery system faces three major obstacles, i.e., appropriate cargo protection, accurately targeted delivery, and site-specific cargo release. In the following review, we summarized the pharmacological actions of siRNA drugs in remolding TME. In addition, the delivery strategies of siRNA drugs and combination therapy with siRNA drugs to remodel TME are thoroughly discussed. In the meanwhile, the most recent advancements in the development of all clinically investigated and commercialized siRNA delivery technologies are also presented. Ultimately, we propose that nanoparticle drug delivery siRNA may be the future research focus of oncogene therapy. This summary offers a thorough analysis and roadmap for general readers working in the field.

Cancer Cell Membrane Wrapped Nanoparticles for the Delivery of a Bcl-2 Inhibitor to Triple-Negative Breast Cancer

Overexpression of the antiapoptotic protein B-cell lymphoma 2 (Bcl-2) is correlated with poor survival outcomes in triple-negative breast cancer (TNBC), making Bcl-2 inhibition a promising strategy to treat this aggressive disease. Unfortunately, Bcl-2 inhibitors developed to date have limited clinical success against solid tumors, owing to poor bioavailability, insufficient tumor delivery, and off-target toxicity. To circumvent these problems, we loaded the Bcl-2 inhibitor ABT-737 in poly(lactic-co-glycolic acid) (PLGA) nanoparticles (NPs) that were wrapped with phospholipid membranes derived from 4T1 murine mammary cancer cells, which mimic the growth and metastasis of human TNBC. We show that the biomimetic cancer cell membrane coating enabled the NPs to preferentially target 4T1 TNBC cells over noncancerous mammary epithelial cells in vitro and significantly increased NP accumulation in orthotopic 4T1 tumors in mice after intravenous injection by over 2-fold compared to poly(ethylene glycol)-poly(lactide-co-glycolic) (PEG-PLGA) copolymer NPs. Congruently, the ABT-737 loaded, cancer cell membrane-wrapped PLGA NPs (ABT CCNPs) induced higher levels of apoptosis in TNBC cells in vitro than ABT-737 delivered freely or in PEG-PLGA NPs. When tested in a syngeneic spontaneous metastasis model, the ABT CCNPs significantly increased apoptosis (evidenced by elevated active caspase-3 and decreased Bcl-2 staining) and decreased proliferation (denoted by reduced Ki67 staining) throughout tumors compared with saline or ABT-loaded PEG-PLGA NP controls. Moreover, the ABT CCNPs did not alter animal weight or blood composition, suggesting that the specificity afforded by the TNBC cell membrane coating mitigated the off-target adverse effects typically associated with ABT-737. Despite these promising results, the low dose of ABT CCNPs administered only modestly reduced primary tumor growth and metastatic nodule formation in the lungs relative to controls. We posit that increasing the dose of ABT CCNPs, altering the treatment schedule, or encapsulating a more potent Bcl-2 inhibitor may yield more robust effects on tumor growth and metastasis. With further development, drug-loaded biomimetic NPs may safely treat solid tumors such as TNBC that are characterized by Bcl-2 overexpression.

Biomembrane-wrapped gene delivery nanoparticles for cancer therapy

As a promising strategy, gene delivery for cancer treatment accepts encouraging progress due to its high efficacy, low toxicity, and exclusive selectivity. However, the delivery efficiency, specific biological distribution, targeted uptake, and biosafety of naked nucleic acid agents still face serious challenges, which limit further clinical application. To overcome the above bottleneck, safe and efficient functional nanovectors are developed to improve the delivery efficiency of nucleic acid agents. In recent years, emerging membrane-wrapped biomimetic nanoparticles (MBNPs) based on the concept of "imitating nature" are well known for their advantages, such as low immunogenicity and long cycle time, and especially play a crucial role in improving the overall efficiency of gene delivery and reducing adverse reactions. Therefore, combining MBNPs and gene delivery is an effective strategy to enhance tumor treatment efficiency. This review presents the mechanism of gene therapy and the current obstacles to gene delivery. Remarkably, the latest development of gene delivery MBNPs and the strategies to overcome these obstacles are summarized. Finally, the future challenges and prospects of gene delivery MBNPs toward clinical transformation are introduced. The principal purpose of this review is to discuss the biomedical potential of gene delivery MBNPs for cancer therapy and to provide guidance for further enhancing the efficiency of tumor gene therapy.

Cell membrane-coated nanomaterials for cancer therapy

With the development of nanotechnology, nanoparticles have emerged as a delivery carrier for tumor drug therapy, which can improve the therapeutic effect by increasing the stability and solubility and prolonging the half-life of drugs. However, nanoparticles are foreign substances for humans, are easily cleared by the immune system, are less targeted to tumors, and may even be toxic to the body. As a natural biological material, cell membranes have unique biological properties, such as good biocompatibility, strong targeting ability, the ability to evade immune surveillance, and high drug-carrying capacity. In this article, we review cell membrane-coated nanoparticles (CMNPs) and their applications to tumor therapy. First, we briefly describe CMNP characteristics and applications. Second, we present the characteristics and advantages of different cell membranes as well as nanoparticles, provide a brief description of the process of CMNPs, discuss the current status of their application to tumor therapy, summarize their shortcomings for use in cancer therapy, and propose future research directions. This review summarizes the research progress on CMNPs in cancer therapy in recent years and assesses remaining problems, providing scholars with new ideas for future research on CMNPs in tumor therapy.

Surface engineering of hollow gold nanoparticle with mesenchymal stem cell membrane and MUC-1 aptamer for targeted theranostic application against metastatic breast cancer

Mesenchymal stem cell membrane (MSCM)-coated biomimetic doxorubicin-loaded hollow gold nanoparticles were fabricated and decorated with MUC1 aptamer in order to provide smart theranostic platform. The prepared targeted nanoscale biomimetic platform was extensively characterized and evaluated in terms of selective delivery of DOX and CT-scan imaging. The fabricated system illustrated spherical morphology with 118 nm in diameter. Doxorubicin was loaded into the hollow gold nanoparticles through physical absorption technique with encapsulation efficiency and loading content of 77%±10 and 31%±4, respectively. The in vitro release profile demonstrated that the designed platform could respond to acidic environment, pH 5.5 and release 50% of the encapsulated doxorubicin during 48 h, while 14% of the encapsulated doxorubicin was released in physiological condition, pH 7.4 up to 48 h. The in vitro cytotoxicity experiments on 4T1 as MUC1 positive cell line illustrated that the targeted formulation could significantly increase mortality at 0.468 and 0.23 µg/ml of equivalent DOX concentration compared to non-targeted formulation while this cytotoxicity was not observed in CHO as MUC1 negative cell line. Furthermore, in vivo experiments showed high tumor accumulation of the targeted formulation even 24 h after intravenous injection which induced effective tumor growth suppression against 4T1 tumor bearing mice. On the other hand, existence of hollow gold in this platform provided CT scan imaging capability of the tumor tissue in 4T1 tumor bearing mice up to 24 h post-administration. The obtained results indicated that the designed paradigm are promising and safe theranostic system for fighting against metastatic breast cancer.

Biomimetic cell membrane-coated nanocarriers for targeted siRNA delivery in cancer therapy

Small interfering RNA (siRNA) therapeutics for cancer are a focus of increasing research interest. However, the major obstacle to their clinical application is the targeted delivery of siRNA to cancer cells at desirable levels. Cell membrane-coated nanocarriers have the advantage of combining the properties of both cell membranes and nanoparticles (NPs). In this review, we highlight the most common RNAi therapeutics and the extracellular and intracellular barriers to siRNA delivery. Moreover, we discuss clinical applications of different cell membrane-coated nanocarriers for targeted siRNA delivery, including cancer cell membranes (CCMs), platelet membranes, erythrocyte membranes, stem cell membranes, exosome membranes, and hybrid membranes. Taken together, biomimetic cell membrane-coated nanotechnology is a promising strategy for targeted siRNA delivery for cancer treatment.

Advances in nanomaterial-based targeted drug delivery systems

Nanomaterial-based drug delivery systems (NBDDS) are widely used to improve the safety and therapeutic efficacy of encapsulated drugs due to their unique physicochemical and biological properties. By combining therapeutic drugs with nanoparticles using rational targeting pathways, nano-targeted delivery systems were created to overcome the main drawbacks of conventional drug treatment, including insufficient stability and solubility, lack of transmembrane transport, short circulation time, and undesirable toxic effects. Herein, we reviewed the recent developments in different targeting design strategies and therapeutic approaches employing various nanomaterial-based systems. We also discussed the challenges and perspectives of smart systems in precisely targeting different intravascular and extravascular diseases.

Nanodecoys: A Quintessential Candidate to Augment Theranostic Applications for a Plethora of Diseases

Nanoparticles (NPs) designed for various theranostic purposes have hugely impacted scientific research in the field of biomedicine, bringing forth hopes of a future revolutionized area called nanomedicine. A budding advancement in this area is the conjugation of various cell membranes onto nanoparticles to develop biomimetic cells called 'Nanodecoys' (NDs), which can imitate the functioning of natural cells. This technology of coating cell membranes on NPs has enhanced the working capabilities of nano-based techniques by initiating effective navigation within the bodily system. Due to the presence of multiple functional moieties, nanoparticles coated with cell membranes hold the ability to interact with complex biological microenvironments inside the body with ease. Although developed with the initial motive to increase the time of circulation in the bloodstream and stability by coating membranes of red blood cells, it has further outstretched a wide range of cell lines, such as mesenchymal stem cells, beta cells, thrombocytes, white blood cells, and cancer cells. Thus, these cells and the versatile properties they bring along with them open up a brand-new domain in the biomedical industry where different formulations of nanoparticles can be used in appropriate dosages to treat a plethora of diseases. This review comprises recent investigations of nanodecoys in biomedical applications.

Novel Development of Nanoparticles-A Promising Direction for Precise Tumor Management

Although the clinical application of nanoparticles is still limited by biological barriers and distribution, with the deepening of our understanding of nanoparticles over the past decades, people are gradually breaking through the previous limitations in the diagnosis and treatment of tumors, providing novel strategies for clinical decision makers. The transition of nanoparticles from passive targeting to active tumor-targeting by abundant surface-modified nanoparticles is also a development process of precision cancer treatment. Different particles can be used as targeted delivery tools of antitumor drugs. The mechanism of gold nanoparticles inducing apoptosis and cycle arrest of tumor cells has been discovered. Moreover, the unique photothermal effect of gold nanoparticles may be widely used in tumor therapy in the future, with less side effects on surrounding tissues. Lipid-based nanoparticles are expected to overcome the blood-brain barrier due to their special characteristics, while polymer-based nanoparticles show better biocompatibility and lower toxicity. In this paper, we discuss the development of nanoparticles in tumor therapy and the challenges that need to be addressed.

Recent advances of metal-based nanoparticles in nucleic acid delivery for therapeutic applications

Recent efforts in designing nanomaterials to deliver potential therapeutics to the targeted site are overwhelming and palpable. Engineering nanomaterials to deliver biological molecules to exert desirable physiological changes, with minimized side effects and optimal dose, has revolutionized the next-generation therapy for several diseases. The rapid progress of nucleic acids as biopharmaceutics is going to alter the traditional pharmaceutics practices in modern medicine. However, enzymatic instability, large size, dense negative charge (hydrophilic for cell uptake), and unintentional adverse biological responses-such as prolongation of the blood coagulation and immune system activation-hamper the potential use of nucleic acids for therapeutic purposes. Moreover, the safe delivery of nucleic acids into the clinical setting is an uphill task, and several efforts are being put forward to deliver them to targeted cells. Advances in Metal-based NanoParticles (MNPs) are drawing attention due to the unique properties offered by them for drug delivery, such as large surface-area-to-volume ratio for surface modification, increased therapeutic index of drugs through site-specific delivery, increased stability, enhanced half-life of the drug in circulation, and efficient biodistribution to the desired targeted site. Here, the potential of nanoparticles delivery systems for the delivery of nucleic acids, specially MNPs, and their ability and advantages over other nano delivery systems are reviewed.

Application of nanomaterials in combined thermal ablation and immunotherapy for liver tumors

Thermal ablation is one of the important treatments for liver tumors, but the postoperative recurrence rate is high. Thermal ablation has been reported to trigger the release of tumor-associated antigens, which in turn initiates antitumor immune response. However, this anti-tumor immune effect cannot effectively suppress tumor recurrence due to the obstacles of antigen presentation, the formation of tumor-suppressive immune microenvironment, and the hypoxic and hypovascular tumor microenvironment. Therefore, using immunotherapy to enhance the antitumor immune effect after thermal ablation is a potential strategy to improve the prognosis of tumor patients. However, free immune drugs have the disadvantages of poor targeting and short half-life. Nanomaterials have the advantages of strong modifiability, controllable drug ratio, and excellent targeting. Based on the characteristics of the tumor immune microenvironment after thermal ablation, scholars have designed nano-immunopharmaceuticals that can increase the tumor permeability of immune drugs, stimulate antigen presentation, and reshape the tumor immune microenvironment. This review focuses on the role of nanomaterials in tumor ablation combined with immunotherapy for liver tumors.

Development and application of bionic systems consisting of tumor-cell membranes

Malignant tumors pose a serious threat to human health but during the past decade, great progress has been made in the treatment of tumors. The tumor-cell membrane is well constructed and can be used to solve problems in tumor therapy. Tumor-cell membranes exhibit not only high biocompatibility due to their homology but also enhanced therapeutic effects when combined with nanotechnology. Meanwhile, nanomaterials show high selectivity, sensitivity, and clinical transformation potential. Enhanced immunotherapy or tumor vaccines have potential clinical application because of tumor-membrane surface-specific antigens. Several studies have confirmed the feasibility and advantages of using tumor-cell membrane-incorporated nanosystems for tumor therapy. Considering all this, we focus in this review on the application of tumor-cell-membrane bionic platforms and, in the summary, provide ideas for new scientific developments.

Recent advances in biological membrane-based nanomaterials for cancer therapy

Nanomaterials have shown significant advantages in cancer theranostics, owing to their enhanced permeability and retention effect in tumors and multi-function integration capability. Biological membranes, which are collected from various cells and their secreted membrane structures, can further be applied to establish membrane-based nanomaterials with perfect biocompatibility, tumor-targeting capacity, immune-stimulatory activity and adjustable versatility for cancer therapy. In this review, according to their source, membranes are divided into four groups: (1) cell membranes; (2) secretory membranes; (3) engineered membranes; and (4) hybrid membranes. First, cell membranes can be extracted from natural cells of the body, tumor tissue cells, and bacteria. Furthermore, secretory membranes mainly refer to exosome, apoptotic body and bacterial outer membrane vesicle, and membranes with specific protein/peptide expression or therapeutic inclusions are obtained from engineered cells. Finally, a hybrid membrane will be constituted by two or more of the abovementioned membranes. These membranes can form drug-carrying nanoparticles themselves or coat multi-functional nanoparticles, further realizing efficient cancer therapy. We summarize the application of various biological membrane-based nanomaterials in cancer therapy and point out their advantages as well as the places that need to be further improved, providing systematic knowledge of this field and a strategy for further optimization.

Membrane-wrapped nanoparticles for nucleic acid delivery

There is an unmet need for carriers that can deliver nucleic acids (NAs) to cancer cells and tumors to perpetuate gene regulation and manage disease progression. Membrane-wrapped nanoparticles (NPs) can be loaded with exogenously designed nucleic acid cargoes, such as plasmid deoxyribonucleic acid (pDNA), messenger ribonucleic acid (mRNA), small interfering RNA (siRNA), microRNA (miRNA), and immunostimulatory CpG oligodeoxynucleotides (CpG ODNs), to mitigate challenges presented by NAs' undesirable negative charge, hydrophilicity, and relatively large size. By conjugating or encapsulating NAs within membrane-wrapped NPs, various physiological barriers can be overcome so that NAs experience increased blood circulation half-lives and enhanced accumulation in intended sites. This review discusses the status of membrane-wrapped NPs as NA delivery vehicles and their advancement in gene regulation for cancer management in vitro and in vivo. With continued development, membrane-wrapped NPs have great potential as future clinical tools to treat cancer and other diseases with a known genetic basis.

The Future of Tissue-Targeted Lipid Nanoparticle-Mediated Nucleic Acid Delivery

The earliest example of in vivo expression of exogenous mRNA is by direct intramuscular injection in mice without the aid of a delivery vehicle. The current state of the art for therapeutic nucleic acid delivery is lipid nanoparticles (LNP), which are composed of cholesterol, a helper lipid, a PEGylated lipid and an ionizable amine-containing lipid. The liver is the primary organ of LNP accumulation following intravenous administration and is also observed to varying degrees following intramuscular and subcutaneous routes. Delivery of nucleic acid to hepatocytes by LNP has therapeutic potential, but there are many disease indications that would benefit from non-hepatic LNP tissue and cell population targeting, such as cancer, and neurological, cardiovascular and infectious diseases. This review will concentrate on the current efforts to develop the next generation of tissue-targeted LNP constructs for therapeutic nucleic acids.

Cell membrane-based biomimetic nanosystems for advanced drug delivery in cancer therapy: A comprehensive review

Natural types of cells display distinct characteristics with homotypic targeting and extended circulation in the blood, which are worthy of being explored as promising drug delivery systems (DDSs) for cancer therapy. To enhance their delivery efficiency, these cells can be combined with therapeutic agents and artificial nanocarriers to construct the next generation of DDSs in the form of biomimetic nanomedicines. In this review, we present the recent advances in cell membrane-based DDSs (CDDSs) and their applications for efficient cancer therapy. Different sources of cell membranes are discussed, mainly including red blood cells (RBC), leukocytes, cancer cells, stem cells and hybrid cells. Moreover, the extraction methods used for obtaining such cells and the mechanism contributing to the functional action of these biomimetic CDDSs are explained. Finally, a future perspective is proposed to highlight the limitations of CDDSs and the possible resolutions toward clinical transformation of currently developed biomimetic chemotherapies.

Advancements in cell membrane camouflaged nanoparticles: A bioinspired platform for cancer therapy

The idea of employing natural cell membranes as a coating medium for nanoparticles (NPs) endows man-made vectors with natural capabilities and benefits. In addition to retaining the physicochemical characteristics of the NPs, the biomimetic NPs also have the functionality of source cell membranes. It has emerged as a promising approach to enhancing the properties of NPs for drug delivery, immune evasion, imaging, cancer-targeting, and phototherapy sensitivity. Several studies have been reported with a multitude of approaches to reengineering the surface of NPs using biological membranes. Owing to their low immunogenicity and intriguing biomimetic properties, cell-membrane-based biohybrid delivery systems have recently gained a lot of interest as therapeutic delivery systems. This review summarises different kinds of biomimetic NPs reported so far, their fabrication aspects, and their application in the biomedical field. Finally, it briefs on the latest advances available in this biohybrid concept.

Targeting the PD-1/PD-L1 axis for cancer treatment: a review on nanotechnology

Although nanomedicines have been in the oncology field for almost three decades with the introduction of doxil, only a few nanomedicine products have reached approval. Can nanotechnology be a realistic tool to reduce the number of hospital beds? At present, several clinically approved anti-PD-1/PD-L1 antibodies or CAR T cell-based therapies are available; however, the immunotherapy field is far from mature. Will immunotherapy be the fourth pillar of cancer treatment? In this review, we summarized the current status of immunotherapy using PD-1/PD-L1-targeting nanocarriers. The knowledge on material science, therapeutic agents and formulation designs could pave the way for high-efficacy treatment outcomes.

Combinational Chemoimmunotherapy for Breast Cancer by Codelivery of Doxorubicin and PD-L1 siRNA Using a PAMAM-Incorporated Liposomal Nanoplatform

Chemoimmunotherapy can synergistically enhance the therapeutic effects and decrease the side effects by a combined method. However, the effective targeted codelivery of various chemotherapeutic agents and siRNAs remains challenging. Although nanomedicine-based chemoimmunotherapy has shown great potential in cancer treatment in recent years, further effort is needed to simplify the nanocarrier designs and maintain their effective functions. Here, we report a simple but robust multifunctional liposomal nanocarrier that contains a pH-sensitive liposome (LP) shell and a dendritic core for tumor-targeted codelivery of programmed cell death ligand 1 (PD-L1) siRNA and doxorubicin (DOX) (siPD-L1@PM/DOX/LPs). siPD-L1@PM/DOX/LPs had a suitable particle size and zeta potential, excellent stability in serum, and pH-sensitive drug release in vitro. They exhibited significant cell proliferation inhibition compared to free DOX and DOX-loaded LPs and could escape endosomes, effectively release siRNA into the cytoplasm of MCF-7 cells, and significantly reduce the PD-L1 expression on tumor cells. In vivo imaging confirmed high accumulation of siPD-L1@PM/DOX/LPs at the tumor site. More importantly, compared with siPD-L1@PM/LPs or DOX alone, siPD-L1@PM/DOX/LPs were more effective in inhibiting tumor growth and activating cytotoxic T cells in vivo. In conclusion, this nanocarrier may hold promise as a codelivery nanoplatform to improve the treatment of various solid tumors.

Research on the synthesis of nanoparticles of betulinic acid and their targeting antitumor activity

Betulinic acid (BA), a natural pentacyclic lupine-type triterpene, has shown its prominent efficiency on the selective antitumor activity. However, its poor water solubility and bioavailability have limited its application. Herein, targeting nanoparticles were prepared to improve BA-based liposome (BL)'s restricted chemotherapeutic efficacy. Multi-layers membranes from the cancer cells were added as highly penetrative targeting ligands to functionalize the BA-based liposomes. In vitro experiments including the MTT assay and the fluorescence imaging of live/dead staining were adopted to prove its great inhibition in the growth of tumor cells. And it manifests that the antitumor efficacy of BL coated with cell membranes (BLCM) achieves nearly 4.3 times as that of BL under the same conditions in the MTT experiments. In addition, the fluorescence imaging stained with DAPI-FITC was applied to prove the targeting positioning effects on the BLCM. In a nutshell, the nanomedicine has good targeting antitumor efficacy and has great potential in being applied for the personalized cancer clinical treatment.

Cell membrane coated-nanoparticles for cancer immunotherapy

Cancer immunotherapy can effectively inhibit cancer progression by activating the autoimmune system, with low toxicity and high effectiveness. Some of cancer immunotherapy had positive effects on clinical cancer treatment. However, cancer immunotherapy is still restricted by cancer heterogeneity, immune cell disability, tumor immunosuppressive microenvironment and systemic immune toxicity. Cell membrane-coated nanoparticles (CMCNs) inherit abundant source cell-relevant functions, including “self” markers, cross-talking with the immune system, biological targeting, and homing to specific regions. These enable them to possess preferred characteristics, including better biological compatibility, weak immunogenicity, immune escaping, a prolonged circulation, and tumor targeting. Therefore, they are applied to precisely deliver drugs and promote the effect of cancer immunotherapy. In the review, we summarize the latest researches of biomimetic CMCNs for cancer immunotherapy, outline the existing specific cancer immune therapies, explore the unique functions and molecular mechanisms of various cell membrane-coated nanoparticles, and analyze the challenges which CMCNs face in clinical translation.

Simultaneous nanocarrier-mediated delivery of siRNAs and chemotherapeutic agents in cancer therapy and diagnosis: Recent advances

Recently, investigations have revealed that RNA interference (RNAi) has a remarkable potential to decrease cancer burden by downregulating genes. Among various RNAi molecules, small interfering RNA (siRNA) has been more attractive for this goal and is able to silence a target pathological path and promote the degradation of a certain mRNA, resulting in either gain or loss of function of proteins. Moreover, therapeutic siRNAs have exhibited low side effects compared to other therapeutic molecular candidates. Nevertheless, siRNA delivery has its own limitations including quick degradation in circulation, ineffective internalization and low passive uptake by cells, possible toxicity against off-target sites, and inducing unfavorable immune responses. Therefore, delivery tools must be able to specifically direct siRNAs to their target locations without inflicting detrimental effects on other sites. To conquer the mentioned problems, nanocarrier-mediated delivery of siRNAs, using inorganic nanoparticles (NPs), polymers, and lipids, has been developed as a biocompatible delivery approach. In this review, we have discussed recent advances in the siRNA delivery methods that employ nanoparticles, lipids, and polymers, as well as the inorganic-based co-delivery systems used to deliver siRNAs and anticancer agents to target cells.

Nature-inspired dynamic gene-loaded nanoassemblies for the treatment of brain diseases

Gene therapy has great potential to treat brain diseases. However, genetic drugs need to overcome a cascade of barriers for their full potential. The conventional delivery systems often struggle to meet expectations. Natural biological particles that are highly optimized for specific functions in body, can inspire optimization of dynamic gene-loaded nanoassemblies (DGN). The DGN refer to gene loaded nanoassemblies whose functions and structures are changeable in response to the biological microenvironments or can dynamically interact with tissues or cells. The nature-inspired DGN can meet the needs in brain diseases treatment, including i) Non-elimination in blood (N), ii) Across the blood-brain barrier (A), iii) Targeting cells (T), iv) Efficient uptake (U), v) Controllable release (R), vi) Eyeable (E)-abbreviated as the "NATURE". In this Review, from nature to "NATURE", we mainly summarize the specific application of nature-inspired DGN in the "NATURE" cascade process. Furthermore, the Review provides an outlook for this field.

Pre-Clinical and Clinical Applications of Small Interfering RNAs (siRNA) and Co-Delivery Systems for Pancreatic Cancer Therapy

Pancreatic cancer (PC) is one of the leading causes of death and is the fourth most malignant tumor in men. The epigenetic and genetic alterations appear to be responsible for development of PC. Small interfering RNA (siRNA) is a powerful genetic tool that can bind to its target and reduce expression level of a specific gene. The various critical genes involved in PC progression can be effectively targeted using diverse siRNAs. Moreover, siRNAs can enhance efficacy of chemotherapy and radiotherapy in inhibiting PC progression. However, siRNAs suffer from different off target effects and their degradation by enzymes in serum can diminish their potential in gene silencing. Loading siRNAs on nanoparticles can effectively protect them against degradation and can inhibit off target actions by facilitating targeted delivery. This can lead to enhanced efficacy of siRNAs in PC therapy. Moreover, different kinds of nanoparticles such as polymeric nanoparticles, lipid nanoparticles and metal nanostructures have been applied for optimal delivery of siRNAs that are discussed in this article. This review also reveals that how naked siRNAs and their delivery systems can be exploited in treatment of PC and as siRNAs are currently being applied in clinical trials, significant progress can be made by translating the current findings into the clinical settings.

Current Strategies for Cancer Cell-Derived Extracellular Vesicles for Cancer Therapy

Cancer cell-derived extracellular vesicles (CEVs), a novel type of therapeutic agent in cancer treatment, can be prepared from the autocrine secretion of various cancer cells, the direct extraction of cancer cells and the combination of cancer cell-derived membranes with advanced materials. With various bioactive molecules, exosomes are produced by cells for intercellular communication. Although cancer cell-derived exosomes are known to inhibit tumor apoptosis and promote the progression of cancer, researchers have developed various innovative strategies to prepare anti-tumor vesicles from cancer cells. With current strategies for anti-tumor vesicles, four different kinds of CEVs are classified including irradiated CEVs, advanced materials combined CEVs, chemotherapeutic drugs loaded CEVs and genetically engineered CEVs. In this way, CEVs can not only be the carriers for anti-tumor drugs to the target tumor area but also act as immune-active agents. Problems raised in the strategies mainly concerned with the preparation, efficacy and application. In this review, we classified and summarized the current strategies for utilizing the anti-tumor potential of CEVs. Additionally, the challenges and the prospects of this novel agent have been discussed.

Targeted Delivery of Drugs and Genes Using Polymer Nanocarriers for Cancer Therapy

Cancer is one of the primary causes of worldwide human deaths. Most cancer patients receive chemotherapy and radiotherapy, but these treatments are usually only partially efficacious and lead to a variety of serious side effects. Therefore, it is necessary to develop new therapeutic strategies. The emergence of nanotechnology has had a profound impact on general clinical treatment. The application of nanotechnology has facilitated the development of nano-drug delivery systems (NDDSs) that are highly tumor selective and allow for the slow release of active anticancer drugs. In recent years, vehicles such as liposomes, dendrimers and polymer nanomaterials have been considered promising carriers for tumor-specific drug delivery, reducing toxicity and improving biocompatibility. Among them, polymer nanoparticles (NPs) are one of the most innovative methods of non-invasive drug delivery. Here, we review the application of polymer NPs in drug delivery, gene therapy, and early diagnostics for cancer therapy.

Recent trends in biodegradable polyester nanomaterials for cancer therapy

Biodegradable polyester nanomaterials-based drug delivery vehicles (DDVs) have been largely used in most of the cancer treatments due to its high biological performance and wider applications. In several previous studies, various biodegradable and biocompatible polyester backbones were used which are poly(lactic acid) (PLA), poly(ε-caprolactone) (PCL), poly(propylene fumarate) (PPF), poly(lactic-co-glycolic acid) (PLGA), poly(propylene carbonate) (PPC), polyhydroxyalkanoates (PHA), and poly(butylene succinate) (PBS). These polyesters were fabricated into therapeutic nanoparticles that carry drug molecules to the target site during the cancer disease treatment. In this review, we elaborately discussed the chemical synthesis of different synthetic polyesters and their use as nanodrug carriers (NCs) in cancer treatment. Further, we highlighted in brief the recent developments of metal-free semi-aromatic polyester nanomaterials along with its role as cancer drug delivery vehicles.

Cell membrane cloaked nanomedicines for bio-imaging and immunotherapy of cancer: Improved pharmacokinetics, cell internalization and anticancer efficacy

Despite enormous advancements in the field of oncology, the innocuous and effectual treatment of various types of malignancies remained a colossal challenge. The conventional modalities such as chemotherapy, radiotherapy, and surgery have been remained the most viable options for cancer treatment, but lacking of target-specificity, optimum safety and efficacy, and pharmacokinetic disparities are their impliable shortcomings. Though, in recent decades, numerous encroachments in the field of onco-targeted drug delivery have been adapted but several limitations (i.e., short plasma half-life, early clearance by reticuloendothelial system, immunogenicity, inadequate internalization and localization into the onco-tissues, chemoresistance, and deficient therapeutic efficacy) associated with these onco-targeted delivery systems limits their clinical viability. To abolish the aforementioned inadequacies, a promising approach has been emerged in which stealthing of synthetic nanocarriers has been attained by cloaking them into the natural cell membranes. These biomimetic nanomedicines not only retain characteristics features of the synthetic nanocarriers but also inherit the cell-membrane intrinsic functionalities. In this review, we have summarized preparation methods, mechanism of cloaking, and pharmaceutical and therapeutic superiority of cell-membrane camouflaged nanomedicines in improving the bio-imaging and immunotherapy against various types of malignancies. These pliable adaptations have revolutionized the current drug delivery strategies by optimizing the plasma circulation time, improving the permeation into the cancerous microenvironment, escaping the immune evasion and rapid clearance from the systemic circulation, minimizing the immunogenicity, and enabling the cell-cell communication via cell membrane markers of biomimetic nanomedicines. Moreover, the preeminence of cell-membrane cloaked nanomedicines in improving the bio-imaging and theranostic applications, alone or in combination with phototherapy or radiotherapy, have also been pondered.