Improved melanoma suppression with target-delivered TRAIL and Paclitaxel by a multifunctional nanocarrier

Design and Application of pH-Responsive Liposomes for Site-Specific Delivery of Cytotoxin from Cobra Venom

Background

Current immunotherapies with unexpected severe side effects and treatment resistance have not resulted in the desired outcomes for patients with melanoma, and there is a need to discover more effective medications. Cytotoxin (CTX) from Cobra Venom has been established to have favorable cytolytic activity and antitumor efficacy and is regarded as a promising novel anticancer agent. However, amphiphilic CTX with excellent anionic phosphatidylserine lipid-binding ability may also damage normal cells.

Methods

We developed pH-responsive liposomes with a high CTX load (CTX@PSL) for targeted acidic-stimuli release of drugs in the tumor microenvironment. The morphology, size, zeta potential, drug-release kinetics, and preservation stability were characterized. Cell uptake, apoptosis-promoting effects, and cytotoxicity were assessed using MTT assay and flow cytometry. Finally, the tissue distribution and antitumor effects of CTX@PSL were systematically assessed using an in vivo imaging system.

Results

CTX@PSL exhibited high drug entrapment efficiency, drug loading, stability, and a rapid release profile under acidic conditions. These nanoparticles, irregularly spherical in shape and small in size, can effectively accumulate at tumor sites (six times higher than free CTX) and are rapidly internalized into cancer cells (2.5-fold higher cell uptake efficiency). CTX@PSL displayed significantly stronger cytotoxicity (IC50 0.25 μg/mL) and increased apoptosis in than the other formulations (apoptosis rate 71.78±1.70%). CTX@PSL showed considerably better tumor inhibition efficacy than free CTX or conventional liposomes (tumor inhibition rate 79.78±5.93%).

Conclusion

Our results suggest that CTX@PSL improves tumor-site accumulation and intracellular uptake for sustained and targeted CTX release. By combining the advantages of CTX and stimuli-responsive nanotechnology, the novel CTX@PSL nanoformulation is a promising therapeutic candidate for cancer treatment.

A dual drug-loaded peptide system with morphological transformation prolongs drug retention and inhibits breast cancer growth

The treatment of breast cancer relies heavily on chemotherapy, but chemotherapy is limited by the disadvantages of poor targeting, susceptibility to extracellular matrix (ECM) interference and a short duration of action in tumor cells. To address these limitations, we developed an amphipathic peptide containing an RGD motif, Pep1, that encapsulated paclitaxel (PTX) and losartan potassium (LP) to form the drug-loaded peptide PL/Pep1. PL/Pep1 self-assembled into spherical nanoparticles (NPs) under normal physiological conditions and transformed into aggregates containing short nanofibers at acidic pH. The RGD peptide facilitated tumor targeting and the aggregates prolonged drug retention in the tumor, which allowed more drug to reach and accumulate in the tumor tissue to promote apoptosis and remodel the tumor microenvironment. The results of in vitro and in vivo experiments confirmed the superiority of PL/Pep1 in terms of targeting, prolonged retention and facilitated penetration for antitumor therapy. In conclusion, amphipathic peptides as coloaded drug carriers are a new platform and strategy for breast cancer chemotherapy.

Cell-Penetrating Peptide-Based Delivery of Macromolecular Drugs: Development, Strategies, and Progress

Cell-penetrating peptides (CPPs), developed for more than 30 years, are still being extensively studied due to their excellent delivery performance. Compared with other delivery vehicles, CPPs hold promise for delivering different types of drugs. Here, we review the development process of CPPs and summarize the composition and classification of the CPP-based delivery systems, cellular uptake mechanisms, influencing factors, and biological barriers. We also summarize the optimization routes of CPP-based macromolecular drug delivery from stability and targeting perspectives. Strategies for enhanced endosomal escape, which prolong its half-life in blood, improved targeting efficiency and stimuli-responsive design are comprehensively summarized for CPP-based macromolecule delivery. Finally, after concluding the clinical trials of CPP-based drug delivery systems, we extracted the necessary conditions for a successful CPP-based delivery system. This review provides the latest framework for the CPP-based delivery of macromolecular drugs and summarizes the optimized strategies to improve delivery efficiency.

A Nano-targeted Co-delivery System Based on Gene Regulation and Molecular Blocking Strategy for Synergistic Enhancement of Platinum Chemotherapy Sensitivity in Ovarian Cancer

Ovarian cancer (OC) has a low five-year survival rate, mainly because of its drug resistance to chemotherapy. It is the key to reverse drug resistance to combine multiple sensitization pathways to play a synergistic role. A nano scaled targeted co-delivery system (P123-PEI-G12, PPG) modified by bifunctional peptide tLyP-1-NLS (G12) was fabricated by using Pluronic P123 conjugated with low molecular weight polyethyleneimine (PEI). This delivery system can co-delivery Olaparib (Ola) and p53 plasmids to synergistically enhance the sensitivity of OC to platinum-based chemotherapy. P53@P123-PEI-G2/Ola (Co-PPGs) can achieve efficient tumor accumulation and cellular internalization through G12-mediated targeting. Co-PPGs then break down in the tumor cells, releasing the drug. Co-PPGs significantly enhanced the sensitivity of cisplatin (DDP) in platinum-resistant ovarian cancer (PROC) and synergistically inhibited the proliferation of PROC in vitro and in vivo. The sensitizing and synergistic effects of Co-PPGs were related to the activation of p53, inhibition of poly-ADP-ribose polymerase (PARP) and p-glycoprotein (P-gp) expression. This work provides a promising strategy for the effective treatment of PROC.

Codelivery of TRAIL and Mitomycin C via Liposomes Shows Improved Antitumor Effect on TRAIL-Resistant Tumors

Although tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) constitutes a promising antitumor drug, tumor resistance to TRAIL has become a major obstacle in its clinical application. Mitomycin C (MMC) is an effective TRAIL-resistant tumor sensitizer, which indicates a potential utility of combination therapy. However, the efficacy of this combination therapy is limited owing to its short half-life and the cumulative toxicity of MMC. To address these issues, we successfully developed a multifunctional liposome (MTLPs) with human TRAIL protein on the surface and MMC encapsulated in the internal aqueous phase to codeliver TRAIL and MMC. MTLPs are uniform spherical particles that exhibit efficient cellular uptake by HT-29 TRAIL-resistant tumor cells, thereby inducing a stronger killing effect compared with control groups. In vivo assays revealed that MTLPs efficiently accumulated in tumors and safely achieved 97.8% tumor suppression via the synergistic effect of TRAIL and MMC in an HT-29 tumor xenograft model while ensuring biosafety. These results suggest that the liposomal codelivery of TRAIL and MMC provides a novel approach to overcome TRAIL-resistant tumors.

Exploiting Nanomedicine for Cancer Polychemotherapy: Recent Advances and Clinical Applications

The most important limitations of chemotherapeutic agents are severe side effects and the development of multi-drug resistance. Recently, the clinical successes achieved with immunotherapy have revolutionized the treatment of several advanced-stage malignancies, but most patients do not respond and many of them develop immune-related adverse events. Loading synergistic combinations of different anti-tumor drugs in nanocarriers may enhance their efficacy and reduce life-threatening toxicities. Thereafter, nanomedicines may synergize with pharmacological, immunological, and physical combined treatments, and should be increasingly integrated in multimodal combination therapy regimens. The goal of this manuscript is to provide better understanding and key considerations for developing new combined nanomedicines and nanotheranostics. We will clarify the potential of combined nanomedicine strategies that are designed to target different steps of the cancer growth as well as its microenvironment and immunity interactions. Moreover, we will describe relevant experiments in animal models and discuss issues raised by translation in the human setting.

Advances in Lipid-Based Codelivery Systems for Cancer and Inflammatory Diseases

Combination therapy targeting multiple therapeutic targets is a favorable strategy to achieve better therapeutic outcomes in cancer and inflammatory diseases. Codelivery is a subfield of drug delivery that aims to achieve combined delivery of diverse therapeutic cargoes within the same delivery system, thereby ensuring delivery to the same site and providing an opportunity to tailor the release kinetics as desired. Among the wide range of materials being investigated in the design of codelivery systems, lipids have stood out on account of their low toxicity, biocompatibility, and ease of formulation scale-up. This review highlights the advances of the last decade in lipid-based codelivery systems focusing on the codelivery of drug-drug, drug-nucleic acid, nucleic acid-nucleic acid, and protein therapeutic-based combinations for targeted therapy in cancer and inflammatory diseases.

Recent Advances in the Development of Nanodelivery Systems Targeting the TRAIL Death Receptor Pathway

The TRAIL (TNF-related apoptosis-inducing ligand) apoptotic pathway is extensively exploited in the development of targeted antitumor therapy due to TRAIL specificity towards its cognate receptors, namely death receptors DR4 and DR5. Although therapies targeting the TRAIL pathway have encountered many obstacles in attempts at clinical implementation for cancer treatment, the unique features of the TRAIL signaling pathway continue to attract the attention of researchers. Special attention is paid to the design of novel nanoscaled delivery systems, primarily aimed at increasing the valency of the ligand for improved death receptor clustering that enhances apoptotic signaling. Optionally, complex nanoformulations can allow the encapsulation of several therapeutic molecules for a combined synergistic effect, for example, chemotherapeutic agents or photosensitizers. Scaffolds for the developed nanodelivery systems are fabricated by a wide range of conventional clinically approved materials and innovative ones, including metals, carbon, lipids, polymers, nanogels, protein nanocages, virus-based nanoparticles, dendrimers, DNA origami nanostructures, and their complex combinations. Most nanotherapeutics targeting the TRAIL pathway are aimed at tumor therapy and theranostics. However, given the wide spectrum of action of TRAIL due to its natural role in immune system homeostasis, other therapeutic areas are also involved, such as liver fibrosis, rheumatoid arthritis, Alzheimer's disease, and inflammatory diseases caused by bacterial infections. This review summarizes the recent innovative developments in the design of nanodelivery systems modified with TRAIL pathway-targeting ligands.

Multifunctional nanoparticle for cancer therapy

Cancer is a complex disease associated with a combination of abnormal physiological process and exhibiting dysfunctions in multiple systems. To provide effective treatment and diagnosis for cancer, current treatment strategies simultaneously focus on various tumor targets. Based on the rapid development of nanotechnology, nanocarriers have been shown to exhibit excellent potential for cancer therapy. Compared with nanoparticles with single functions, multifunctional nanoparticles are believed to be more aggressive and potent in the context of tumor targeting. However, the development of multifunctional nanoparticles is not simply an upgraded version of the original function, but involves a sophisticated system with a proper backbone, optimized modification sites, simple preparation method, and efficient function integration. Despite this, many well-designed multifunctional nanoparticles with promising therapeutic potential have emerged recently. Here, to give a detailed understanding and analyzation of the currently developed multifunctional nanoparticles, their platform structures with organic or inorganic backbones were systemically generalized. We emphasized on the functionalization and modification strategies, which provide additional functions to the nanoparticle. We also discussed the application combination strategies that were involved in the development of nanoformulations with functional crosstalk. This review thus provides an overview of the construction strategies and application advances of multifunctional nanoparticles.

Recent advances in selective and targeted drug/gene delivery systems using cell-penetrating peptides

Biological cell membranes are a natural barrier for living cells. In the last few decades, the cell membrane has been the main hurdle in the efficient delivery of bioactive and therapeutic agents. To increase the drug efficacy of these agents, additional mediators have been considered. Cell-penetrating peptides (CPPs), a series of oligopeptides composed of mostly hydrophobic and/or positively charged side chains, can increase the interaction with the cell membrane. CPP-based delivery platforms have shown great potential for the efficient and direct cytosol delivery of various cargos, including genes, proteins, and small molecule drugs. Bypassing endocytosis allows the CPP-based delivery systems greater defense against the degradation of protein-based drugs than other drug delivery systems. However, the delivery of CPPs exhibits intrinsically non-specific targeting, which limits their medical applications. To endow CPPs with specific targeting ability, the conjugation of pH-sensitive, enzyme-specific cleavable, and multiple targeting ligands has been reported. Optimization of the length and sequence of CPPs is still needed for various drugs of different sizes and surface charges. Toxicity issues in CPP-based delivery systems should be addressed carefully before clinical use.

The functions and molecular mechanisms of Tribbles homolog 3 (TRIB3) implicated in the pathophysiology of cancer

Currently, cancer ranks as the second leading cause of death worldwide, and at the same time, the burden of cancer continues to increase. The underlying molecular pathways involved in the initiation and development of cancer are the subject of considerable research worldwide. Further understanding of these pathways may lead to new cancer treatments. Growing data suggest that Tribble's homolog 3 (TRIB3) is essential in oncogenesis in many types of cancer. The mammalian tribbles family's proteins regulate various cellular and physiological functions, such as the cell cycle, stress response, signal transduction, propagation, development, differentiation, immunity, inflammatory processes, and metabolism. To exert their activities, Tribbles proteins must alter key signaling pathways, including the mitogen-activated protein kinase (MAPK) and phosphatidylinositol 3 kinase (PI3K)/AKT pathways. Recent evidence supports that TRIB3 dysregulation has been linked to various diseases, including tumor development and chemoresistance. It has been speculated that TRIB3 may either promote or inhibit the onset and development of cancer. However, it is still unclear how TRIB3 performs this dual function in cancer. In this review, we present and discuss the most recent data on the role of TRIB3 in cancer pathophysiology and chemoresistance. Furthermore, we describe in detail the molecular mechanism TRIB3 regulates in cancer.

pH and its applications in targeted drug delivery

Physiologic pH is vital for the normal functioning of tissues and varies in different parts of the body. The varying pH of the body has been exploited to design pH-sensitive smart oral, transdermal and vaginal drug delivery systems (DDS). The DDS demonstrated promising results in hard-to-treat diseases such as cancer and Helicobacter pylori infection. In some cases, a change in pH of tissues or body fluids has also been employed as a useful diagnostic biomarker. This paper aims to comprehensively review the development and applications of pH-sensitive DDS as well as recent advances in the field.

Phytochemicals as Chemo-Preventive Agents and Signaling Molecule Modulators: Current Role in Cancer Therapeutics and Inflammation

Cancer is one of the deadliest non communicable diseases. Numerous anticancer medications have been developed to target the molecular pathways driving cancer. However, there has been no discernible increase in the overall survival rate in cancer patients. Therefore, innovative chemo-preventive techniques and agents are required to supplement standard cancer treatments and boost their efficacy. Fruits and vegetables should be tapped into as a source of compounds that can serve as cancer therapy. Phytochemicals play an important role as sources of new medication in cancer treatment. Some synthetic and natural chemicals are effective for cancer chemoprevention, i.e., the use of exogenous medicine to inhibit or impede tumor development. They help regulate molecular pathways linked to the development and spread of cancer. They can enhance antioxidant status, inactivating carcinogens, suppressing proliferation, inducing cell cycle arrest and death, and regulating the immune system. While focusing on four main categories of plant-based anticancer agents, i.e., epipodophyllotoxin, camptothecin derivatives, taxane diterpenoids, and vinca alkaloids and their mode of action, we review the anticancer effects of phytochemicals, like quercetin, curcumin, piperine, epigallocatechin gallate (EGCG), and gingerol. We examine the different signaling pathways associated with cancer and how inflammation as a key mechanism is linked to cancer growth.

Delivery of Theranostic Nanoparticles to Various Cancers by Means of Integrin-Binding Peptides

Active targeting of tumors is believed to be the key to efficient cancer therapy and accurate, early-stage diagnostics. Active targeting implies minimized off-targeting and associated cytotoxicity towards healthy tissue. One way to acquire active targeting is to employ conjugates of therapeutic agents with ligands known to bind receptors overexpressed onto cancer cells. The integrin receptor family has been studied as a target for cancer treatment for almost fifty years. However, systematic knowledge on their effects on cancer cells, is yet lacking, especially when utilized as an active targeting ligand for particulate formulations. Decoration with various integrin-targeting peptides has been reported to increase nanoparticle accumulation in tumors ≥ 3-fold when compared to passively targeted delivery. In recent years, many newly discovered or rationally designed integrin-binding peptides with excellent specificity towards a single integrin receptor have emerged. Here, we show a comprehensive analysis of previously unreviewed integrin-binding peptides, provide diverse modification routes for nanoparticle conjugation, and showcase the most notable examples of their use for tumor and metastases visualization and eradication to date, as well as possibilities for combined cancer therapies for a synergetic effect. This review aims to highlight the latest advancements in integrin-binding peptide development and is directed to aid transition to the development of novel nanoparticle-based theranostic agents for cancer therapy.

A new core–shell-type nanoparticle loaded with paclitaxel/norcantharidin and modified with APRPG enhances anti-tumor effects in hepatocellular carcinoma

Nanoparticle delivery systems have been shown to improve the therapeutic efficacy of anti-cancer drugs, including a variety of drugs for the treatment of hepatocellular carcinoma (HCC). However, the current systems show some limitations, and the delivery of more effective nanoparticle systems for anti-HCC drugs with better targeting ability are needed. Here, we created paclitaxel (PTX)/norcantharidin (NCTD)-loaded core–shell lipid nanoparticles modified with a tumor neovasculature-targeted peptide (Ala-Pro-Arg-Pro-Gly, APRPG) and investigated their anti-tumor effects in HCC. Core–shell-type lipid nanoparticles (PTX/NCTD-APRPG-NPs) were established by combining poly(lactic-co-glycolic acid) (PLGA)-wrapped PTX with phospholipid-wrapped NCTD, followed by modification with APRPG. For comparison, PTX-loaded PLGA nanoparticles (PTX-NPs) and PTX/NCTD-loaded core–shell-type nanoparticles without APRPG (PTX/NCTD-NPs) were prepared. The in vitro and in vivo anti-tumor effects were examined in HepG2 cells and tumor-bearing mice, respectively. Morphological and release characterization showed that PTX/NCTD-APRPG-NPs were prepared successfully and achieved up to 90% release of PTX in a sustained manner. Compared with PTX/NCTD-NPs, PTX/NCTD-APRPG-NPs significantly enhanced the uptake of PTX. Notably, the inhibition of proliferation and migration of hepatoma cells was significantly higher in the PTX/NCTD-APRPG-NP group than those in the PTX-NP and PTX/NCTD-NP groups, which reflected significantly greater anti-tumor properties as well. Furthermore, key molecules in cell proliferation and apoptosis signaling pathways were altered most in the PTX/NCTD-APRPG-NP group, compared with the PTX-NP and PTX/NCTD-NP groups. Collectively, PTX/NCTD-loaded core–shell lipid nanoparticles modified with APRPG enhance the effectiveness of anti-HCC drugs and may be an effective system for the delivery of anti-HCC drugs.

Photothermal immunotherapy of melanoma using TLR-7 agonist laden tobacco mosaic virus with polydopamine coat

Photothermal therapy (PTT) is a promising cancer treatment that debulks tumors locally while priming immune responses. However, PTT as a standalone treatment approach often has limited systemic efficacy, motivating the development of synergistic combination approaches. Toward this goal, herein, the tobacco mosaic virus (TMV) was loaded with a small molecule immunomodulator, toll-like receptor 7 agonist (1V209), and its surface was coated with photothermal biopolymer polydopamine (PDA). The resulting 1V209-laden and PDA-coated TMV was used to treat B16F10 dermal melanoma in C57BL/6 mice. 1V209-TMV-PDA was intratumorally injected and irradiated using an 808-nm near infrared laser. 60 % of the mice receiving PTT with intratumoral 1V209-TMV-PDA + laser remained alive at the end point - in contrast to only 20 % survivors were observed in the control group. Immunological analysis indicates systemic anti-tumor immunity being induced by the combination therapy with a greater number of tumor-specific T cells (as determined by a splenocyte assay). This study highlights the potential of TMV versatility as a multifunctional nano-platform for combined PTT-immunotherapy.

Ultra-small lipid carriers with adjustable release profiles for synergistic treatment of drug-resistant ovarian cancer

Multidrug resistance has dramatically compromised the effectiveness of paclitaxel (PTX). The combined application of PTX and tetrandrine (TET) is a promising avenue in drug-resistant cancer therapy. However, poor drug release and limited intracellular drug accumulation greatly impede this combinational antitumor therapy. To address this problem, we successfully developed a tunable controlled release lipid platform (PT@usNLC) for coordinated drug delivery. The drug release rate of PT@usNLC can be tuned by varying the lipid ratio, which has potential to maximize the therapeutic effects of combined drugs. The TET release rate from PT@usNLC was faster than PTX, which could restore the sensitivity of tumor cells to PTX and exert a synergistic antitumor effect. The appropriate size of PT@usNLC could effectively increase the intracellular drug accumulation. Bothin vitroandin vivostudies revealed that PT@usNLC significantly enhanced the therapeutic effect compared to conventional therapies. This study provides a new strategy for resistant ovarian cancer therapy.

Deletion of TRIB3 disrupts the tumor progression induced by integrin αvβ3 in lung cancer

BACKGROUND

Integrin αvβ3 has been proposed as crucial determinant for tumor sustained progression and a molecular marker for the estimation of tumor angiogenesis. Our study suggested that integrin αvβ3 could efficiently promote lung cancer cell proliferation and stem-like phenotypes in a tribbles homolog 3 (TRIB3) dependent manner.

RESULT

Integrin αvβ3 could mediate the activation of FAK/AKT pro-survival signaling pathway. Meanwhile, activated TRIB3 interacted with AKT to upregulated FOXO1 and SOX2 expression, resulting in sustained tumor progression in lung cancer. Our further analysis revealed that TRIB3 was significantly upregulated in lung tumor tissues and correlated with the poor outcome in clinical patients, indicating the potential role of TRIB3 in diagnostic and prognostic estimation for patients with lung cancer.

CONCLUSION

Our study showed here for the first time that integrin αvβ3 promote lung cancer development by activating the FAK/AKT/SOX2 axis in a TRIB3 dependent signaling pathway, and interrupting TRIB3/AKT interaction significantly improved the outcome of chemotherapy in tumor-bearing mice, representing a promising therapeutic strategy in lung cancer.

Emerging nanomedicines of paclitaxel for cancer treatment

Malignant tumor is still a leading threat to human health. Despite the rapid development of targeted therapeutic strategies, any treatment specifically acting on single target would inevitably suffer from tumor resistance, largely due to the genetic instability and variability of tumor cells. Thus, traditional therapies such as broad-spectrum chemotherapy would certainly occupy an important position in clinical cancer therapy. Nevertheless, most chemotherapeutic drugs have long been criticized for unsatisfactory therapeutic efficacy with severe off-target toxicity. Although several chemotherapeutic nanomedicines with improved therapeutic safety have been applied in clinics, the therapeutic outcomes still do not fulfill expectation. To address this challenge, enormous efforts have been devoted to developing novel nano-formulations for efficient delivery of chemotherapeutic drugs. Herein, we aim to outline the latest progression in the emerging nanomedicines of paclitaxel (PTX), with special attention to the functional nanocarriers, self-delivering prodrug-nanoassemblies and combination nanotherapeutics of PTX. Finally, the challenges and opportunities of these functional PTX nanomedicines in clinical translation are spotlighted.

Polydopamine-based nanoplatform for photothermal ablation with long-term immune activation against melanoma and its recurrence

The high risk of tumor recurrence presents a big challenge in melanoma therapy. Photothermal therapy (PTT) has merged as a powerful weapon against tumor in recent years, which produces tumor-associated antigens (TAA) and recruits dendritic cells (DCs) to tumor sites through immunogenic cell death (ICD) for immune activation. However, due to the lack of activation signals of DCs, the immune effect induced by PTT is not sufficient to inhibit the recurrence and proliferation of tumor. To efficiently cooperate PTT and immunotherapy to circumvent tumor recurrence, here we constructed a polydopamine (PDA) based core-shell nanoplatform loading CpG ODNs to elicit robust photothermal ablation and antitumor immune responses. Cationized polydopamine coated with hyaluronic acid (HA) shell was proven an efficient photothermal agent that increased the surface temperature of tumor by 16 °C and induced ICD. CpG ODNs effectively induced maturation of DCs by elevating the expression of co-stimulating markers. PTT combined with CpG ODNs achieved a remarkable synergistic treatment effect in the maturation of DCs and activation of T cells in melanoma-bearing mice model compared with PTT or CpG ODNs alone. Furthermore, in a tumor recurrence model, photothermal-immune combination therapy increased the infiltration of CTLs in distant tumor compared with PTT or CpG ODNs alone. The combination therapy overcame insufficient immunity at distant tumor caused by PTT alone and relieved immunosuppression microenvironment of the tumor. Hence, the PDA based core-shell nanoplatform presents a potent photo-immunotherapy against proliferation and recurrence of melanoma. STATEMENT OF SIGNIFICANCE: In order to solve the insufficient immunity induced by photothermal therapy (PTT), CpG ODNs were utilized to enhance the weak immune response mediated by PTT through inducing DCs maturation. Hence, we designed a polydopamine (PDA) based core-shell nanoplatform loading CpG ODNs followed by hyaluronic acid named PPP/CpG/HA to elicit robust photothermal ablation and antitumor immune responses. CpG ODNs were delivered to the tumor site through the targeting effect of the HA shell. The core-shell nanoplatform achieved a remarkable synergistic treatment effect in the maturation of DCs and activation of T cells, thereby overcoming insufficient immunity at distant tumor caused by PTT alone. The core-shell nanoplatform presents a potent photo-immunotherapy against proliferation and recurrence of melanoma.

Site-Specific Vesicular Drug Delivery System for Skin Cancer: A Novel Approach for Targeting

Skin cancer, one of the most prevalent cancers worldwide, has demonstrated an alarming increase in prevalence and mortality. Hence, it is a public health issue and a high burden of disease, contributing to the economic burden in its treatment. There are multiple treatment options available for skin cancer, ranging from chemotherapy to surgery. However, these conventional treatment modalities possess several limitations, urging the need for the development of an effective and safe treatment for skin cancer that could provide targeted drug delivery and site-specific tumor penetration and minimize unwanted systemic toxicity. Therefore, it is vital to understand the critical biological barriers involved in skin cancer therapeutics for the optimal development of the formulations. Various nanocarriers for targeted delivery of chemotherapeutic drugs have been developed and extensively studied to overcome the limitations faced by topical conventional dosage forms. A site-specific vesicular drug delivery system appears to be an attractive strategy in topical drug delivery for the treatment of skin malignancies. In this review, vesicular drug delivery systems, including liposomes, niosomes, ethosomes, and transfersomes in developing novel drug delivery for skin cancer therapeutics, are discussed. Firstly, the prevalence statistics, current treatments, and limitations of convention dosage form for skin cancer treatment are discussed. Then, the common type of nanocarriers involved in the research for skin cancer treatment are summarized. Lastly, the utilization of vesicular drug delivery systems in delivering chemotherapeutics is reviewed and discussed, along with their beneficial aspects over other nanocarriers, safety concerns, and clinical aspects against skin cancer treatment.

NK Cells in the Tumor Microenvironment as New Potential Players Mediating Chemotherapy Effects in Metastatic Melanoma

Until the last decade, chemotherapy was the standard treatment for metastatic cutaneous melanoma, even with poor results. The introduction of immune checkpoints inhibitors (ICIs) radically changed the outcome, increasing 5-year survival from 5% to 60%. However, there is still a large portion of unresponsive patients that would need further therapies. NK cells are skin-resident innate cytotoxic lymphocytes that recognize and kill virus-infected as well as cancer cells thanks to a balance between inhibitory and activating signals delivered by surface molecules expressed by the target. Since NK cells are equipped with cytotoxic machinery but lack of antigen restriction and needing to be primed, they are nowadays gaining attention as an alternative to T cells to be exploited in immunotherapy. However, their usage suffers of the same limitations reported for T cells, that is the loss of immunogenicity by target cells and the difficulty to penetrate and be activated in the suppressive tumor microenvironment (TME). Several evidence showed that chemotherapy used in metastatic melanoma therapy possess immunomodulatory properties that may restore NK cells functions within TME. Here, we will discuss the capability of such chemotherapeutics to: i) up-regulate melanoma cells susceptibility to NK cell-mediated killing, ii) promote NK cells infiltration within TME, iii) target other immune cell subsets that affect NK cells activities. Alongside traditional systemic melanoma chemotherapy, a new pharmacological strategy based on nanocarriers loaded with chemotherapeutics is developing. The use of nanotechnologies represents a very promising approach to improve drug tolerability and effectiveness thanks to the targeted delivery of the therapeutic molecules. Here, we will also discuss the recent developments in using nanocarriers to deliver anti-cancer drugs within the melanoma microenvironment in order to improve chemotherapeutics effects. Overall, we highlight the possibility to use standard chemotherapeutics, possibly delivered by nanosystems, to enhance NK cells anti-tumor cytotoxicity. Combined with immunotherapies targeting NK cells, this may represent a valuable alternative approach to treat those patients that do not respond to current ICIs.

Anti-melanoma effects of concomitant inhibition of SIRT1 and SIRT3 in BrafV600E/PtenNULL mice

Novel therapeutic strategies are required for the effective and lasting treatment of metastatic melanoma, one of the deadliest skin malignancies. In this study, we determined the anti-melanoma efficacy of 4'-bromo-resveratrol (4'-BR), which is a small molecule dual inhibitor of SIRT1 and SIRT3 in a Braf^V600E/Pten^NULL mouse model that recapitulates human disease, including metastases. Tumors were induced by topical application of 4-hydroxy-tamoxifen on shaved backs of 10-week-old mice, and the effects of 4'-BR (5-30 mg/kg b.wt.; intraperitoneally; 3d/week for 5 weeks) were assessed on melanoma development and progression. We found that 4'-BR at a dose of 30 mg/kg significantly reduced size and volume of primary melanoma tumors, as well as lung metastasis, with no adverse effects. Further, mechanistic studies on tumors showed significant modulation in markers of proliferation, survival and melanoma progression. As SIRT1 and SIRT3 are linked to immunomodulation, we performed differential gene expression analysis via NanoString PanCancer Immune Profiling panel (770 genes). Our data demonstrated that 4'-BR significantly downregulated genes related to metastasis-promotion, chemokine/cytokine-regulation, and innate/adaptive immune functions. Overall, inhibition of SIRT1 and SIRT3 by 4'-BR is a promising anti-melanoma therapy with anti-metastatic and immunomodulatory activities warranting further detailed studies, including clinical investigations.

Combination immunotherapy of chlorogenic acid liposomes modified with sialic acid and PD-1 blockers effectively enhances the anti-tumor immune response and therapeutic effects

Melanoma is one of the most common malignant tumors. The anti-PD-1 antibody is used for the treatment of metastatic melanoma. Treatment success is only 35–40% and a range of immune-related adverse reactions can occur. Combination of anti-PD1 antibody therapy with other oncology therapies has been attempted. Herein, we assessed whether chlorogenic acid liposomes modified with sialic acid (CA-SAL) combined with anti-PD1 antibody treatment was efficacious as immunotherapy for melanoma. CA-SAL liposomes were prepared and characterized. In a mouse model of B16F10 tumor, mice were treated with an anti-PD1 antibody, CA-SAL, or combination of CA-SAL + anti-PD1 antibody, and compared with no treatment controls. The tumor inhibition rate, tumor-associated macrophages (TAMs) phenotype, T-cell activity, and safety were investigated. We observed a significant decrease in the proportion of M2-TAMs and CD4⁺Fop3⁺ T cells, while there was a significant increase in the proportion of M1-TAMs and CD8⁺ T cells, and in the activity of T cells, and thus in the tumor inhibition rate. No significant toxicity was observed in major organs. CA-SAL and anti-PD1 Ab combination therapy presented synergistic anti-tumor activity, which enhanced the efficacy of the PD-1 checkpoint blocker in a mouse model of melanoma. In summary, combination immunotherapy of CA-SAL and anti-PD1 Ab has broad prospects in improving the therapeutic effect of melanoma, and may provide a new strategy for clinical treatment.

Integrin α2β1 Targeting DGEA-Modified Liposomal Doxorubicin Enhances Antitumor Efficacy against Breast Cancer

Breast cancer was the leading cause of newly diagnosed cases of tumors in 2020, ranking as the second highest cause of female death. Chemotherapy remains the conventional treatment of choice for breast tumors in most clinical cases. However, it is often accompanied by a poor prognosis and severe side effects, resulting from an insufficient accumulation of the drug at tumor sites and an unsystematic distribution of the drug across the body. Inspired by the fact that breast tumor cells overexpress integrin α2β1 on the surface, we designed and constructed an integrin α2β1 targeting DGEA-modified liposomal doxorubicin (DGEA-Lipo-DOX) platform for application in breast cancer therapy. The DGEA-Lipo-DOX was stable with a uniform particle size of 121.1 ± 3.8 nm and satisfactory drug encapsulation. Demonstrated in vitro and in vivo, the constructed platform exhibited improved antitumor ability. The DGEA-Lipo-DOX showed 4-fold enhanced blood circulation and 6-fold increased accumulation of DOX at the tumor sites compared to those of free DOX, resulting in a significantly enhanced antitumor efficacy in tumor-bearing mice. A preliminary safety evaluation suggested that the systemic toxicity of DOX was relieved by DGEA-Lipo delivery. Collectively, binding integrin α2β1 by DGEA may represent an alternative therapeutic strategy for potentially safer breast cancer treatment.

Progress in tumour-targeted drug delivery based on cell-penetrating peptides

Since the discovery of cell-penetrating peptides (CPP) in the 1980s, they have played a unique role in various fields owing to their excellent and unique cell membrane penetration function. In particular, in the treatment of tumours, CPPS have been used to deliver several types of 'cargos' to cancer cells. To address the insufficient targeting ability, non-selectivity, and blood instability, activatable cell-penetrating peptides, which can achieve targeted drug delivery in tumour treatment, enhance curative effects, and reduce toxicity have been developed. This study reviews the application of different cell-penetrating peptides in tumour-targeted delivery, overcoming multidrug resistance, organelle targeting, tumour imaging, and diagnosis, and summarises the different mechanisms of activatable cell-penetrating peptides in detail.

Multifunctional nanoplatforms co-delivering combinatorial dual-drug for eliminating cancer multidrug resistance

Clinically, the primary cause of chemotherapy failure belongs to the occurrence of cancer multidrug resistance (MDR), which directly leads to the recurrence and metastasis of cancer along with high mortality. More and more attention has been paid to multifunctional nanoplatform-based dual-therapeutic combination to eliminate resistant cancers. In addition to helping both cargoes improve hydrophobicity and pharmacokinetic properties, increase bioavailability, release on demand and enhance therapeutic efficacy with low toxic effects, these smart co-delivery nanocarriers can even overcome drug resistance. Here, this review will not only present different types of co-delivery nanocarriers, but also summarize targeted and stimuli-responsive combination nanomedicines. Furthermore, we will focus on the recent progress in the co-delivery of dual-drug using such intelligent nanocarriers for surmounting cancer MDR. Whereas it remains to be seriously considered that there are some knotty issues in the fight against MDR of cancers via using co-delivery nanoplatforms, including limited intratumoral retention, the possible changes of combinatorial ratio under complex biological environments, drug release sequence from the nanocarriers, and subsequent free-drug resistance after detachment from the nanocarriers. It is hoped that, with the advantage of continuously developing nanomaterials, two personalized therapeutic agents in combination can be better exploited to achieve the goal of cooperatively combating cancer MDR, thus advancing the time to clinical transformation.

Nanocarrier-Based Drug Delivery for Melanoma Therapeutics

Melanoma, as a tumor cell derived from melanocyte transformation, has the characteristics of malignant proliferation, high metastasis, rapid recurrence, and a low survival rate. Traditional therapy has many shortcomings, including drug side effects and poor patient compliance, and so on. Therefore, the development of an effective treatment is necessary. Currently, nanotechnologies are a promising oncology treatment strategy because of their ability to effectively deliver drugs and other bioactive molecules to targeted tissues with low toxicity, thereby improving the clinical efficacy of cancer therapy. In this review, the application of nanotechnology in the treatment of melanoma is reviewed and discussed. First, the pathogenesis and molecular targets of melanoma are elucidated, and the current clinical treatment strategies and deficiencies of melanoma are then introduced. Following this, we discuss the main features of developing efficient nanosystems and introduce the latest reports in the literature on nanoparticles for the treatment of melanoma. Subsequently, we review and discuss the application of nanoparticles in chemotherapeutic agents, immunotherapy, mRNA vaccines, and photothermal therapy, as well as the potential of nanotechnology in the early diagnosis of melanoma.

Taxanes in cancer treatment: Activity, chemoresistance and its overcoming

Since 1984, when paclitaxel was approved by the FDA for the treatment of advanced ovarian carcinoma, taxanes have been widely used as microtubule-targeting antitumor agents. However, their historic classification as antimitotics does not describe all their functions. Indeed, taxanes act in a complex manner, altering multiple cellular oncogenic processes including mitosis, angiogenesis, apoptosis, inflammatory response, and ROS production. On the one hand, identification of the diverse effects of taxanes on oncogenic signaling pathways provides opportunities to apply these cytotoxic drugs in a more rational manner. On the other hand, this may facilitate the development of novel treatment modalities to surmount anticancer drug resistance. In the latter respect, chemoresistance remains a major impediment which limits the efficacy of antitumor chemotherapy. Taxanes have shown impact on key molecular mechanisms including disruption of mitotic spindle, mitosis slippage and inhibition of angiogenesis. Furthermore, there is an emerging contribution of cellular processes including autophagy, oxidative stress, epigenetic alterations and microRNAs deregulation to the acquisition of taxane resistance. Hence, these two lines of findings are currently promoting a more rational and efficacious taxane application as well as development of novel molecular strategies to enhance the efficacy of taxane-based cancer treatment while overcoming drug resistance. This review provides a general and comprehensive picture on the use of taxanes in cancer treatment. In particular, we describe the history of application of taxanes in anticancer therapeutics, the synthesis of the different drugs belonging to this class of cytotoxic compounds, their features and the differences between them. We further dissect the molecular mechanisms of action of taxanes and the molecular basis underlying the onset of taxane resistance. We further delineate the possible modalities to overcome chemoresistance to taxanes, such as increasing drug solubility, delivery and pharmacokinetics, overcoming microtubule alterations or mitotic slippage, inhibiting drug efflux pumps or drug metabolism, targeting redox metabolism, immune response, and other cellular functions.

Development, Characterization and Use of Liposomes as Amphipathic Transporters of Bioactive Compounds for Melanoma Treatment and Reduction of Skin Inflammation: A Review

The skin is the largest organ in the human body, providing a barrier to the external environment. It is composed of three layers: epidermis, dermis and hypodermis. The most external epidermis is exposed to stress factors that may lead to skin conditions such as photo-aging and skin cancer. Some treatments for skin disease utilize the incorporation of drugs or bioactive compounds into nanocarriers known as liposomes. Liposomes are membranes whose sizes range from nano to micrometers and are composed mostly of phospholipids and cholesterol, forming similar structures to cell membranes. Thus, skin treatments with liposomes have lower toxicity in comparison to traditional treatment routes such as parenteral and oral. Furthermore, addition of edge activators to the liposomes decreases the rigidity of the bilayer structure making it deformable, thereby improving skin permeability. Liposomes are composed of an aqueous core and a lipidic bilayer, which confers their amphiphilic property. Thus, they can carry hydrophobic and hydrophilic compounds, even simultaneously. Current applications of these nanocarriers are mainly in the cosmetic and pharmaceutic industries. Nevertheless, new research has revealed promising results regarding the effectiveness of liposomes for transporting bioactive compounds through the skin. Liposomes have been well studied; however, additional research is needed on the efficacy of liposomes loaded with bioactive peptides for skin delivery. The objective of this review is to provide an up-to-date description of existing techniques for the development of liposomes and their use as transporters of bioactive compounds in skin conditions such as melanoma and skin inflammation. Furthermore, to gain an understanding of the behavior of liposomes during the process of skin delivery of bioactive compounds into skin cells.