Light-responsive nanomedicine for cancer immunotherapy

Immunotherapy emerged as a paradigm shift in cancer treatments, which can effectively inhibit cancer progression by activating the immune system. Remarkable clinical outcomes have been achieved through recent advances in cancer immunotherapy, including checkpoint blockades, adoptive cellular therapy, cancer vaccine, and tumor microenvironment modulation. However, extending the application of immunotherapy in cancer patients has been limited by the low response rate and side effects such as autoimmune toxicities. With great progress being made in nanotechnology, nanomedicine has been exploited to overcome biological barriers for drug delivery. Given the spatiotemporal control, light-responsive nanomedicine is of great interest in designing precise modality for cancer immunotherapy. Herein, we summarized current research utilizing light-responsive nanoplatforms to enhance checkpoint blockade immunotherapy, facilitate targeted delivery of cancer vaccines, activate immune cell functions, and modulate tumor microenvironment. The clinical translation potential of those designs is highlighted and challenges for the next breakthrough in cancer immunotherapy are discussed.     

Biointerface engineering nanoplatforms for cancer-targeted drug delivery

Over the past decade, nanoparticle-based therapeutic modalities have become promising strategies in cancer therapy. Selective delivery of anticancer drugs to the lesion sites is critical for elimination of the tumor and an improved prognosis. Innovative design and advanced biointerface engineering have promoted the development of various nanocarriers for optimized drug delivery. Keeping in mind the biological framework of the tumor microenvironment, biomembrane-camouflaged nanoplatforms have been a research focus, reflecting their superiority in cancer targeting. In this review, we summarize the development of various biomimetic cell membrane-camouflaged nanoplatforms for cancer-targeted drug delivery, which are classified according to the membranes from different cells. The challenges and opportunities of the advanced biointerface engineering drug delivery nanosystems in cancer therapy are discussed.     

Manipulation of immune‒vascular crosstalk: new strategies towards cancer treatment

Tumor vasculature is characterized by aberrant structure and function, resulting in immune suppressive profiles of tumor microenvironment through limiting immune cell infiltration into tumors, endogenous immune surveillance and immune cell function. Vascular normalization as a novel therapeutic strategy tends to prune some of the immature blood vessels and fortify the structure and function of the remaining vessels, thus improving immune stimulation and the efficacy of immunotherapy. Interestingly, the presence of “immune‒vascular crosstalk” enables the formation of a positive feedback loop between vascular normalization and immune reprogramming, providing the possibility to develop new cancer therapeutic strategies. The applications of nanomedicine in vascular-targeting therapy in cancer have gained increasing attention due to its specific physical and chemical properties. Here, we reviewed the recent advances of effective routes, especially nanomedicine, for normalizing tumor vasculature. We also summarized the development of enhancing nanoparticle-based anticancer drug delivery via the employment of transcytosis and mimicking immune cell extravasation. This review explores the potential to optimize nanomedicine-based therapeutic strategies as an alternative option for cancer treatment.     

Recent advances in the liposomal nanovesicles based immunotherapy in the treatment of cancer: A review

Immunotherapy, along with chemotherapy, targeted delivery, radiation and surgery has become one of the most common cancer treatments. The aim of cancer immunology is to use the bodys immune system to combat tumors and develop a robust antitumor immune response. In the last few years, immune checkpoint inhibitors and chimeric antigen receptor-modified T cells have made substantial advancements in cancer immunotherapy. By boosting cell type-specific delivery and immunological responses, nanocarriers like liposomes have the ability to enhance greater immune responses. The efficacy of anti-tumor therapeutics is being significantly improved as liposomes can assist in resolving a number of issues that can arise from a variety of cancer immunotherapies. Since, liposomes can be loaded with both hydrophilic and hydrophobic drugs and protect the immunotherapeutic agents loaded inside the core, they offer significant advantages over other nano delivery systems. The use of liposomes for accurate and timely delivery of immunotherapies to particular targeted neoplasms, with little or no injury to healthy cells, maximizes immunotherapy efficacy. Liposomes are also suitable vehicles for delivering medications simultaneously with other therapies such as chemotherapy, radiation, and phototherapy. Liposomal nanoparticles will be introduced and used as an objective immunotherapy delivery system for great precision, making them a viable cancer treatment approach.With an emphasis on dendritic cells, T cells, tumor and natural killer cells, and macrophages; outline of many forms of immune-therapies in oncology and cutting-edge advances in liposomal nanovesicles for cancer immunotherapy are covered in this review.     

Nanomedicines modulating tumor immunosuppressive cells to enhance cancer immunotherapy

Cancer immunotherapy has veered the paradigm of cancer treatment. Despite recent advances in immunotherapy for improved antitumor efficacy, the complicated tumor microenvironment (TME) is highly immunosuppressive, yielding both astounding and unsatisfactory clinical successes. In this regard, clinical outcomes of currently available immunotherapy are confined to the varied immune systems owing in large part to the lack of understanding of the complexity and diversity of the immune context of the TME. Various advanced designs of nanomedicines could still not fully surmount the delivery barriers of the TME. The immunosuppressive TME may even dampen the efficacy of antitumor immunity. Recently, some nanotechnology-related strategies have been inaugurated to modulate the immunosuppressive cells within the tumor immune microenvironment (TIME) for robust immunotherapeutic responses. In this review, we will highlight the current understanding of the immunosuppressive TIME and identify disparate subclasses of TIME that possess an impact on immunotherapy, especially those unique classes associated with the immunosuppressive effect. The immunoregulatory cell types inside the immunosuppressive TIME will be delineated along with the existing and potential approaches for immunosuppressive cell modulation. After introducing the various strategies, we will ultimately outline both the novel therapeutic targets and the potential issues that affect the efficacy of TIME-based nanomedicines.     

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.     

The benefits and challenges associated with the use of drug delivery systems in cancer therapy

The use of drug delivery systems as nanocarriers for chemotherapeutic agents can improve the pharmacological properties of drugs by altering drug pharmacokinetics and biodistribution. Among the many drug delivery systems available, both micelles and liposomes have gained the most attention in recent years due to their clinical success. There are several formulations of these nanocarrier systems in various stages of clinical trials, as well as currently clinically approved liposomal-based drugs. In this review, we discuss these drug carrier systems, as well as current efforts that are being made in order to further improve their delivery efficacy through the incorporation of targeting ligands. In addition, this review discusses aspects of drug resistance attributed to the remodeling of the extracellular matrix that occurs during tumor development and progression, as well as to the acidic, hypoxic, and glucose-deprived tumor microenvironment. Finally, we address future prospective approaches to overcoming drug resistance by further modifications made to these drug delivery systems, as well as the possibility of coencapsulation/coadministration of various drugs aimed to surmount some of these microenvironmental-influenced obstacles for efficacious drug delivery in chemotherapy.     

食管鳞癌的肿瘤免疫微环境和免疫检查点抑制剂研究进展

食管鳞状细胞癌(esophageal squamous cell carcinoma, ESCC)是食管癌的主要组织学类型, 占全球病例的90%。尽管已经开展了广泛的研究和治疗, 但其预后仍较差。近年来, 抑制程序性死亡受体-1(programmed death-1, PD-1)或程序性死亡受体配体-1(programmed death ligand-1, PD-L1)的单抗在包含食管癌在内的多种恶性肿瘤中获得了较好的疗效。然而, 由于耐药性, 只有少数患者得到了临床获益。因此, 在临床中, 应明确能够精确预测的生物标志物, 以便进行个体化免疫治疗。由于肿瘤免疫微环境可能会影响患者对免疫检查点抑制剂的反应, 因此, 肿瘤免疫(如肿瘤细胞的PD-L1表达、肿瘤浸润性淋巴细胞、肿瘤相关巨噬细胞和髓系来源的肿瘤抑制细胞)在ESCC中值得进一步研究。本文综述了近年来有关ESCC中肿瘤免疫微环境和免疫检查点抑制剂的研究进展。     

Immune cell membrane-based biomimetic nanomedicine for treating cancer metastasis

Metastasis is the leading cause of cancer-related death. Despite extensive treatment, the prognosis for patients with metastatic cancer remains poor. In addition to conventional surgical resection, radiotherapy, immunotherapy, chemotherapy, and targeted therapy, various nanobiomaterials have attracted attention for their enhanced antitumor performance and low off-target effects. However, nanomedicines exhibit certain limitations in clinical applications, such as rapid clearance from the body, low biological stability, and poor targeting ability. Biomimetic methods utilize the natural biomembrane to mimic or hybridize nanoparticles and circumvent some of these limitations. Considering the involvement of immune cells in the tumor microenvironment of the metastatic cascade, biomimetic methods using immune cell membranes have been proposed with unique tumor-homing ability and high biocompatibility. In this review, we explore the impact of immune cells on various processes of tumor metastasis. Furthermore, we summarize the synthesis and applications of immune cell membrane-based nanocarriers increasing therapeutic efficacy against cancer metastases via immune evasion, prolonged circulation, enhanced tumor accumulation, and immunosuppression of the tumor microenvironment. Moreover, we describe the prospects and existing challenges in clinical translation.     

肿瘤免疫治疗新靶标PGE2受体EP4的研究进展

肿瘤免疫治疗已成为人们对抗癌症的重要手段，但响应率低仍是目前亟需解决的关键问题。大量研究表明，逆转肿瘤免疫抑制是阻断肿瘤免疫逃逸、增强和扩大免疫疗法疗效的重要策略。前列腺素E₂（PGE₂）是肿瘤微环境中的强效免疫介质，可特异性结合细胞膜上的七次跨膜蛋白EP4受体，诱导肿瘤微环境免疫抑制，驱动肿瘤免疫逃逸。特异性阻断PGE₂/EP4信号通路可有效解除肿瘤微环境免疫抑制，增强抗肿瘤免疫反应，促进肿瘤消退。本文从EP4受体的结构、信号转导、调控机制及其拮抗剂开发现状等方面阐述了EP4受体在肿瘤免疫治疗领域的新进展和新发现，并展望了新的发展方向。     

Light-controllable charge-reversal nanoparticles with polyinosinic-polycytidylic acid for enhancing immunotherapy of triple negative breast cancer

Nucleic acid drugs are highly applicable for cancer immunotherapy with promising therapeutic effects, while targeting delivery of these drugs to disease lesions remains challenging. Cationic polymeric nanoparticles have paved the way for efficient delivery of nucleic acid drugs, and achieved stimuli-responsive disassembly in tumor microenvironment (TME). However, TME is highly heterogeneous between individuals, and most nanocarriers lack active-control over the release of loaded nucleic acid drugs, which will definitely reduce the therapeutic efficacy. Herein, we have developed a light-controllable charge-reversal nanoparticle (LCCN) with controlled release of polyinosinic-polycytidylic acid [Poly(I:C)] to treat triple negative breast cancer (TNBC) by enhanced photodynamic immunotherapy. The nanoparticles keep suitably positive charge for stable loading of Poly(I:C), while rapidly reverse to negative charge after near-infrared light irradiation to release Poly(I:C). LCCN-Poly(I:C) nanoparticles trigger effective phototoxicity and immunogenic cell death on 4T1 tumor cells, elevate antitumor immune responses and inhibit the growth of primary and abscopal 4T1 tumors in mice. The approach provides a promising strategy for controlled release of various nucleic acid-based immune modulators, which may enhance the efficacy of photodynamic immunotherapy against TNBC     

Emerging nanomedicine-based therapeutics for hematogenous metastatic cascade inhibition: Interfering with the crosstalk between “seed and soil”

Despite considerable progresses in cancer treatment, tumor metastasis is still a thorny issue, which leads to majority of cancer-related deaths. In hematogenous metastasis, the concept of “seed and soil” suggests that the crosstalk between cancer cells (seeds) and premetastatic niche (soil) facilitates tumor metastasis. Considerable efforts have been dedicated to inhibit the tumor metastatic cascade, which is a highly complicated process involving various pathways and biological events. Nonetheless, satisfactory therapeutic outcomes are rarely observed, since it is a great challenge to thwart this multi-phase process. Recent advances in nanotechnology-based drug delivery systems have shown great potential in the field of anti-metastasis, especially compared with conventional treatment methods, which are limited by serious side effects and poor efficacy. In this review, we summarized various factors involved in each phase of the metastatic cascade ranging from the metastasis initiation to colonization. Then we reviewed current approaches of targeting these factors to stifle the metastatic cascade, including modulating primary tumor microenvironment, targeting circulating tumor cells, regulating premetastatic niche and eliminating established metastasis. Additionally, we highlighted the multi-phase targeted drug delivery systems, which hold a better chance to inhibit metastasis. Besides, we demonstrated the limitation and future perspectives of nanomedicine-based anti-metastasis strategies.     

Inflammatory fibroblasts in cancer

The association between inflammation and cancer has been studied widely. Indeed, the tumor microenvironment is influenced by inflammatory cells and affects tumor progression, tumor growth, and the survival of cancer cells. Also, the tumor microenvironment is essential to invasion and metastasis of cancer. Fibroblasts, immune cells, the extracellular matrix and other various components all constitute the tumor stroma, ordinarily referred to as the ‘reactive stroma’. Cancer-associated fibroblasts (CAFs), which are activated fibroblasts and one of the components of the tumor microenvironment, are associated with cancer progression, invasiveness and metastasis, and their functional contributions to these processes are beginning to emerge. CAFs mediate tumor-promoting inflammation through various signaling pathways. Epithelial–mesenchymal transition is a process for producing mesenchymal cells during invasion and metastasis of cancer cells. Fibroblasts have been identified as a key player in this mechanism. In the present review, we summarize the relationships between fibroblasts, inflammatory response, the tumor microenvironment and cancer progression. This review provides useful information for the development of cancer prevention and treatment therapies through controlling the inflammatory responses.     

Drug delivery: Beyond active tumour targeting

Despite improvements in our understanding of cancer and the concept of personalised medicine, cancer is still a major cause of death. It is established that solid tumours are highly heterogeneous, with a complex tumour microenvironment. Indeed, the tumour microenvironment is made up of a collection of immune cells, cancer-activated fibroblasts, and endothelial cells and in some cases a dense extracellular matrix. Accumulating evidence shows that the tumour microenvironment is a major barrier for the effective delivery of therapeutic drugs to tumour cells. Importantly, nanotechnology has come to the forefront as highly effective delivery vehicles for therapeutic agents. This perspective will discuss how nanomedicine can be used to target and deliver therapeutic drugs specifically to tumour cells. Moreover, emerging opportunities to modulate the tumour microenvironment and increase the delivery and efficacy of chemotherapy agents to solid tumours will be highlighted.From the Clinical EditorImproving drug delivery to treatment resistant tumors is a major target of many nanomedicine-based applications. This comprehensive review discusses the currently available and emerging opportunities, in addition to discussing tumor microenvironment modulation to facilitate efficient delivery.     

Impact of immune infiltration on tumor development and progression

Recently, immune infiltration has a crucial role in modulating tumor progression and response to therapy which comprised cells from the innate and adaptive immune response. Infiltrating immune cells can be detected in biopsy specimens and exploited to promote cancer metastasis, angiogenesis and growth. Mounting evidence demonstrates that many cancer-associated cell types within the tumor stromal support tumor growth and development, greatly modifying cancer cell behavior,facilitating invasion and metastasis and controlling sensitivity to drug therapy. Furthermore,immune infiltration of the tumor microenvironment has been associated with improved survival for some patients with solid tumors which have prognostic value. Infiltrating immune cells are both prognostic and predictive of response to cancer therapies. Understanding the interactions between tumor and immune infiltration is critical to find prognostic biomarkers,reduce drug resistance, and developnew therapies.Therefore, cancer immunotherapy based on tumor-infiltrating cell populations has become arguably the most promising advancement in cancer research and therapy in recent years. In this review, we provide an updated overview of key components of the immune infiltrating cells in the tumor microenvironment and the impact of immune infiltration on tumor development and progression. Moreover, we discuss the intricacy of the reciprocal interactions between cancer-associated immune cell types and signal transduction pathways, which appear to be crucially linked to cancer progression in response to the tumor microenvironment. Finally, we focus on the current immunotherapeutic strategies and emerging results from ongoing clinical trials are presented.     

Intratumoral Drug Delivery with Nanoparticulate Carriers

Stiff extracellular matrix, elevated interstitial fluid pressure, and the affinity for the tumor cells in the peripheral region of a solid tumor mass have long been recognized as significant barriers to diffusion of small-molecular-weight drugs and antibodies. However, their impacts on nanoparticle-based drug delivery have begun to receive due attention only recently. This article reviews biological features of many solid tumors that influence transport of drugs and nanoparticles and properties of nanoparticles relevant to their intratumoral transport, studied in various tumor models. We also discuss several experimental approaches employed to date for enhancement of intratumoral nanoparticle penetration. The impact of nanoparticle distribution on the effectiveness of chemotherapy remains to be investigated and should be considered in the design of new nanoparticulate drug carriers.     

中药多糖调控肿瘤微环境的研究进展

肿瘤微环境在肿瘤的发生、发展、转移等环节起到至关重要的作用。多种中药多糖通过调控肿瘤微环境而展现出抗肿瘤作用。从肿瘤微环境的各个组成部分如肿瘤相关成纤维细胞、肿瘤免疫细胞、血管内皮细胞、细胞外基质出发,阐述黄芪多糖、猪苓多糖、香菇多糖、车前子多糖、人参多糖、羊栖菜多糖和枸杞多糖对肿瘤微环境的调控作用,为抗肿瘤中药多糖药物的研发提供参考。     

Brain tumor-targeted drug delivery strategies

Despite the application of aggressive surgery, radiotherapy and chemotherapy in clinics, brain tumors are still a difficult health challenge due to their fast development and poor prognosis. Brain tumor-targeted drug delivery systems, which increase drug accumulation in the tumor region and reduce toxicity in normal brain and peripheral tissue, are a promising new approach to brain tumor treatments. Since brain tumors exhibit many distinctive characteristics relative to tumors growing in peripheral tissues, potential targets based on continuously changing vascular characteristics and the microenvironment can be utilized to facilitate effective brain tumor-targeted drug delivery. In this review, we briefly describe the physiological characteristics of brain tumors, including blood–brain/brain tumor barriers, the tumor microenvironment, and tumor stem cells. We also review targeted delivery strategies and introduce a systematic targeted drug delivery strategy to overcome the challenges.Key words: Barriers targeting, Tumor microenvironment, Tumor cells, Systematic targeted drug delivery     

Cancer Immunotherapy and Nanomedicine

The immune system has the ability to recognize and kill pre-cancer and cancer cells. However, with the immune system’s surveillance, the survival tumor cells learn how to escape the immune system after immunoselection. Cancer immunotherapy develops strategies to overcome these problems. Nanomedicine applications in cancer immunotherapy include the nanodiagnostics and nanobiopharmaceuticals. In cancer nanodiagnostics, it looks for specific “molecular signatures” in cancer cells or their microenvironment by using genomics and proteomics. Nanobiopharmaceuticals is the field that studies nanotechnology-based therapeutic agents and drug carriers. DNA, RNA, peptides, proteins and small molecules can all be used as cancer therapies when formulated in nanocarriers. Currently, cancer vaccines are applied in treatments with existing cancer or to prevent the development of cancer in certain high risk individuals. Most of the non-specific immune activation agents include adjuvants which enhance immunogenicity and accelerate and prolong the response of cancer vaccines. The carriers of vaccines, such as viruses and nanoparticles, have also been in clinical studies for many years. This review will discuss the relationships between the tumor and the immune system, and also will include topics covering the strategies used in eliminating tumors by using nanomedicine.