Recent strategies to overcome breast cancer resistance.

Breast cancer is potentially a lethal disease and a leading cause of death in women. Chemotherapy and radiotherapy are the most frequently used treatment options. Drug resistance in advanced breast cancer limits the therapeutic output of treatment. The leading cause of resistance in breast cancer is endocrine and hormonal imbalance, particularly in triple negative and HER2 positive breast cancers. The efflux of drugs due to p-gp's activity is another leading cause of resistance. Breast cancer resistant protein also contributes significantly. Strategies used to combat resistance include the use of nanoparticles to target drug delivery by co-delivery of chemotherapeutic drugs and genes (siRNA and miRNA) that help to down-regulate genes causing resistance. The siRNA is specific and effectively silences p-gp and other proteins causing resistance. The use of chemosensitizers is also effective in overcoming resistance. Chemo-sensitizers sensitize cancer cells to the effects of chemotherapeutic drugs. Novel anti-neoplastic agents such as antibody-drug conjugates and mesenchymal stem cells are also effective tools used to improve the therapeutic response in breast cancer. Similarly, combination of photo/thermal ablation with chemotherapy can act to overcome breast cancer resistance. In this review, we focus on the mechanism of breast cancer resistance and the nanoparticle-based strategies used to combat resistance in breast cancer.

Evaluation of mAb 2C5-modified dendrimer-based micelles for the co-delivery of siRNA and chemotherapeutic drug in xenograft mice model.

Combination therapy with small interfering RNA (siRNA) and chemotherapeutic drug is proven to be effective in downregulating cancer resistance proteins, such as P-glycoprotein (P-gp). These proteins are involved in multidrug resistance (MDR) of tumors. A targeted formulation capable of delivering siRNA and chemotherapeutic drug will not only downregulate P-gp but also increase the concentration of the chemotherapeutic drug at the site of tumor thereby increasing the therapeutic effect and lowering the systemic exposure. In this study, monoclonal antibody 2C5-modified dendrimer-based micelles were used to co-deliver siRNA and doxorubicin (DOX) to the tumor site in both male and female xenograft mouse model. The nucleosome-specific 2C5 antibody recognizes the cancer cells via the cell-surface bound nucleosomes. The ability of ability of the 2C5-modified formulation to affect the metastasis of highly aggressive triple negative breast cancer cell migration in (MDA-MB-231) was assessed by a wound healing. Further, the therapeutic efficacy of the formulation was assessed by measuring the tumor volume progression in which the 2C5-modified nanoparticle group had a similar tumor volume to the free drug group at the end of the study, although a 50% increase in DOX concentrations in blood was observed after the last dose of nanoparticle. The free drug group on the other hand showed body weight reduction as well as the visible irritation around the injection spot. The treatment group with 2C5-modified micelles has shown to be safe at the current dose of DOX and siRNA. Furthermore, the siRNA mediated P-gp downregualtion was studied using western blotting assay. We observed a 29% reduction of P-gp levels in both males and females with respect to the control (BHG). We also conclude that the dose of DOX and siRNA should be further optimized to have a better efficacy in a metastatic tumor model, which will be the subject of our future studies.

The Interaction of SRL-2 Peptide with LRP-1 Receptor and Identification of Breast Cancer Related Biomarkers: An In-silico Approach.

Background: Breast cancer is a multifaceted disease characterized by genetic and epigenetic changes that lead to uncontrolled cell growth and metastasis. Early detection and treatment are crucial for managing diseases. Objectives: The objective of this study is to investigate the potential of chimeric peptides for drug delivery and to identify biomarkers associated with breast cancer. Recent studies have shown that the low-density lipoprotein receptor-related protein 1 (LRP-1) receptor has a significant impact on the development of breast cancer. In order to facilitate the identification of biomarkers, we have created a chimeric peptide that has been proven to bind successfully to the LRP-1 receptor. Methods: To identify biomarkers, we utilized advanced computational methods to conduct a meta-analysis of microarray data. Specifically, the g:Profiler and eXpression2Kinases (X2K) databases were utilized to identify gene ontologies and transcription factors. We then used the Human Protein Atlas to identify and assess crucial gene expressions. Results: Our results demonstrated that nucleolar and spindle-associated protein 1 (NUSAP1), melatonin receptor 1A (MELT), and cyclin-dependent kinase 1 (CDK1) are three hub genes that play pivotal roles in the pathogenesis of breast cancer. Conclusions: The research findings provide a deeper understanding of the molecular mechanisms involved in developing breast cancer. These findings have significant implications for developing novel therapies and diagnostics for this disease.

Combined thermal ablation and liposomal granulocyte-macrophage colony stimulation factor increases immune cell trafficking in a small animal tumor model.

PURPOSE: To characterize intratumoral immune cell trafficking in ablated and synchronous tumors following combined radiofrequency ablation (RFA) and systemic liposomal granulocyte-macrophage colony stimulation factor (lip-GM-CSF). METHODS: Phase I, 72 rats with single subcutaneous R3230 adenocarcinoma were randomized to 6 groups: a) sham; b&c) free or liposomal GM-CSF alone; d) RFA alone; or e&f) combined with blank liposomes or lip-GM-CSF. Animals were sacrificed 3 and 7 days post-RFA. Outcomes included immunohistochemistry of dendritic cells (DCs), M1 and M2 macrophages, T-helper cells (Th1) (CD4+), cytotoxic T- lymphocytes (CTL) (CD8+), T-regulator cells (T-reg) (FoxP3+) and Fas Ligand activated CTLs (Fas-L+) in the periablational rim and untreated index tumor. M1/M2, CD4+/CD8+ and CD8+/FoxP3+ ratios were calculated. Phase II, 40 rats with double tumors were randomized to 4 groups: a) sham, b) RFA, c) RFA-BL and d) RFA-lip-GM-CSF. Synchronous untreated tumors collected at 7d were analyzed similarly. RESULTS: RFA-lip-GMCSF increased periablational M1, CTL and CD8+/FoxP3+ ratio at 3 and 7d, and activated CTLs 7d post-RFA (p<0.05). RFA-lip-GMSCF also increased M2, T-reg, and reduced CD4+/CD8+ 3 and 7d post-RFA respectively (p<0.05). In untreated index tumor, RFA-lip-GMCSF improved DCs, M1, CTLs and activated CTL 7d post-RFA (p<0.05). Furthermore, RFA-lip-GMSCF increased M2 at 3 and 7d, and T-reg 7d post-RFA (p<0.05). In synchronous tumors, RFA-BL and RFA-lip-GM-CSF improved DC, Th1 and CTL infiltration 7d post-RFA. CONCLUSION: Systemic liposomal GM-CSF combined with RFA improves intratumoral immune cell trafficking, specifically populations initiating (DC, M1) and executing (CTL, FasL+) anti-tumor immunity. Moreover, liposomes influence synchronous untreated metastases increasing Th1, CTL and DCs infiltration.

Advances with Lipid-Based Nanosystems for siRNA Delivery to Breast Cancers.

Breast cancer is the most frequently diagnosed cancer among women. Breast cancer is also the key reason for worldwide cancer-related deaths among women. The application of small interfering RNA (siRNA)-based drugs to combat breast cancer requires effective gene silencing in tumor cells. To overcome the challenges of drug delivery to tumors, various nanosystems for siRNA delivery, including lipid-based nanoparticles that protect siRNA from degradation for delivery to cancer cells have been developed. These nanosystems have shown great potential for efficient and targeted siRNA delivery to breast cancer cells. Lipid-based nanosystems remain promising as siRNA drug delivery carriers for effective and safe cancer therapy including breast cancer. Lipid nanoparticles (LNPs) encapsulating siRNA enable efficient and specific silencing of oncogenes in breast tumors. This review discusses a variety of lipid-based nanosystems including cationic lipids, sterols, phospholipids, PEG-lipid conjugates, ionizable liposomes, exosomes for effective siRNA drug delivery to breast tumors, and the clinical translation of lipid-based siRNA nanosystems for solid tumors.

Dual targeting salinomycin-loaded smart nanomicelles for enhanced accumulation and therapeutic outcome in breast cancer.

Salinomycin is a polyether compound that exhibits strong anticancer activity and is known as the cancer stem cell inhibitor that reached clinical testing. The rapid elimination of nanoparticles from the bloodstream by the mononuclear phagocyte system (MPS), the liver, and the spleen, accompanied by protein corona (PC) formation, restricts in vivo delivery of nanoparticles in the tumor microenvironment (TME). The DNA aptamer (TA1) that successfully targets the overexpressed CD44 antigen on the surface of breast cancer cells suffers strongly from PC formation in vivo. Thus, cleverly designed targeted strategies that lead to the accumulation of nanoparticles in the tumor become a top priority in the drug delivery field. In this work, dual redox/pH-sensitive poly (ß-amino ester) copolymeric micelles modified with CSRLSLPGSSSKpalmSSS peptide and TA1 aptamer, as dual targeting ligands, were synthesized and fully characterized by physico-chemical methods. These biologically transformable stealth NPs were altered into the two ligand-capped (SRL-2 and TA1) NPs for synergistic targeting of the 4T1 breast cancer model after exposure to the TME. The PC formation was reduced sharply in Raw 264.7 cells by increasing the CSRLSLPGSSSKpalmSSS peptide concentration in modified micelles. Surprisingly, in vitro and in vivo biodistribution findings showed that dual targeted micelle accumulation in the TME of 4T1 breast cancer model was significantly higher than that of single modified formulation, along with deep penetration 24 h after intraperitoneal injection. Also, an in vivo treatment study showed remarkable tumor growth inhibition in 4T1 tumor-bearing Balb/c mice, compared to different formulations, with a 10% lower therapeutic dose (TD) of SAL that was confirmed by hematoxylin and eosin staining (H&E) and the TUNEL assay. Overall, in this study, we developed smart transformable NPs in which the body's own engineering systems alter their biological identity, which resulted in a reduction in therapeutic dosage along with a lowered off-target effect.

Advances in Targeted Therapy of Breast Cancer with Antibody-Drug Conjugate.

Antibody-drug conjugates (ADCs) are a potential and promising therapy for a wide variety of cancers, including breast cancer. ADC-based drugs represent a rapidly growing field of breast cancer therapy. Various ADC drug therapies have progressed over the past decade and have generated diverse opportunities for designing of state-of-the-art ADCs. Clinical progress with ADCs for the targeted therapy of breast cancer have shown promise. Off-target toxicities and drug resistance to ADC-based therapy have hampered effective therapy development due to the intracellular mechanism of action and limited antigen expression on breast tumors. However, innovative non-internalizing ADCs targeting the tumor microenvironment (TME) component and extracellular payload delivery mechanisms have led to reduced drug resistance and enhanced ADC effectiveness. Novel ADC drugs may deliver potent cytotoxic agents to breast tumor cells with reduced off-target effects, which may overcome difficulties related to delivery efficiency and enhance the therapeutic efficacy of cytotoxic cancer drugs for breast cancer therapy. This review discusses the development of ADC-based targeted breast cancer therapy and the clinical translation of ADC drugs for breast cancer treatment.

Mechanisms of Resistance and Current Treatment Options for Glioblastoma Multiforme (GBM).

Glioblastoma multiforme (GBM) is a highly aggressive form of brain cancer that is difficult to treat due to its resistance to both radiation and chemotherapy. This resistance is largely due to the unique biology of GBM cells, which can evade the effects of conventional treatments through mechanisms such as increased resistance to cell death and rapid regeneration of cancerous cells. Additionally, the blood-brain barrier makes it difficult for chemotherapy drugs to reach GBM cells, leading to reduced effectiveness. Despite these challenges, there are several treatment options available for GBM. The standard of care for newly diagnosed GBM patients involves surgical resection followed by concurrent chemoradiotherapy and adjuvant chemotherapy. Emerging treatments include immunotherapy, such as checkpoint inhibitors, and targeted therapies, such as bevacizumab, that attempt to attack specific vulnerabilities in GBM cells. Another promising approach is the use of tumor-treating fields, a type of electric field therapy that has been shown to slow the growth of GBM cells. Clinical trials are ongoing to evaluate the safety and efficacy of these and other innovative treatments for GBM, intending to improve with outcomes for patients.

Role of circular RNA and its delivery strategies to cancer - An overview.

With the passage of years and the progress of research on ribonucleic acids, the range of forms in which these molecules have been observed grows. One of them, discovered relatively recently, is circular RNA - covalently closed circles (circRNA). In recent years, there has been a huge increase in the interest of researchers in this group of molecules. It entailed a significant increase in the state of knowledge about them, which in turn caused a dramatic change in their perception. Rather than seeing circular RNAs as curiosities that represent a minor information noise in a cell or a result of RNA misprocessing, they came to be regarded as a common, essential, and potentially extremely useful group of molecules. Nevertheless, the current state of the art of circRNA is full of white cards. A lot of valuable information has been obtained from high-throughput methods to study whole transcriptomes, but many issues related to circular RNAs still need to be clarified. Presumably, each answer obtained will raise several new questions. However, circRNAs have a wealth of potential applications, including therapeutic applications.

Approaches to Improve EPR-Based Drug Delivery for Cancer Therapy and Diagnosis.

The innovative development of nanomedicine has promised effective treatment options compared to the standard therapeutics for cancer therapy. However, the efficiency of EPR-targeted nanodrugs is not always pleasing as it is strongly prejudiced by the heterogeneity of the enhanced permeability and retention effect (EPR). Targeting the dynamics of the EPR effect and improvement of the therapeutic effects of nanotherapeutics by using EPR enhancers is a vital approach to developing cancer therapy. Inadequate data on the efficacy of EPR in humans hampers the clinical translation of cancer drugs. Molecular targeting, physical amendment, or physiological renovation of the tumor microenvironment (TME) are crucial approaches for improving the EPR effect. Advanced imaging technologies for the visualization of EPR-induced nanomedicine distribution in tumors, and the use of better animal models, are necessary to enhance the EPR effect. This review discusses strategies to enhance EPR effect-based drug delivery approaches for cancer therapy and imaging technologies for the diagnosis of EPR effects. The effort of studying the EPR effect is beneficial, as some of the advanced nanomedicine-based EPR-enhancing approaches are currently undergoing clinical trials, which may be helpful to improve EPR-induced drug delivery and translation to clinics.

Co-Encapsulation of Drugs for Topical Application-A Review.

Achieving the best possible outcome for the therapy is the main goal of a medicine. Therefore, nanocarriers and co-delivery strategies were invented to meet this need, as they can benefit many diseases. This approach was applied specifically for cancer treatment, with some success. However, these strategies may benefit many other clinical issues. Skin is the largest and most exposed organ of the human body, with physiological and psychological properties. Due to its exposition and importance, it is not difficult to understand how many skin diseases may impact on patients' lives, representing an important burden for society. Thus, this review aims to summarize the state of the art in research concerning nanocarriers and co-delivery strategies for topical agents' applications targeting skin diseases. The challenge for the medicine of the future is to deliver the drug with spatial and temporal control. Therefore, the co-encapsulation of drugs and the appropriate form of administration for them are so important and remain as unmet needs.

Antibody-modified DNase I micelles specifically recognize the neutrophil extracellular traps (NETs) and promote their degradation.

Neutrophil extracellular traps (NETs) are structures consisting of decondensed chromatin with associated proteins, including histones and antimicrobial peptides, released from activated neutrophils. They are believed to be one of the body's first lines of defense against infectious agents. Despite their beneficial effect on the immune response process, some studies indicate that their excessive formation and the associated accumulation of extracellular DNA (eDNA) together with other polyelectrolytes (F-actin) plays an important role in the pathogenesis of many diseases. Thus NETs formation and removal are clinically significant. The monoclonal antibody 2C5 has strong specificity for intact nucleohistones (NS) and targets NS in NETs as we previously confirmed. Creation of a nano preparation that can specifically recognize and destroy NETs represents the aim for treatment many diseases. 2C5 antibody functionalized micelles coated with DNase I were created to achieve this aim.

Biopolymer-Based Nanosystems for siRNA Drug Delivery to Solid Tumors including Breast Cancer.

Nanobiopolymers such as chitosan, gelatin, hyaluronic acid, polyglutamic acid, lipids, peptides, exosomes, etc., delivery systems have prospects to help overwhelmed physiological difficulties allied with the delivery of siRNA drugs to solid tumors, including breast cancer cells. Nanobiopolymers have favorable stimuli-responsive properties and therefore can be utilized to improve siRNA delivery platforms to undruggable MDR metastatic cancer cells. These biopolymeric siRNA drugs can shield drugs from pH degradation, extracellular trafficking, and nontargeted binding sites and are consequently suitable for drug internalization in a controlled-release fashion. In this review, the utilization of numerous biopolymeric compounds such as siRNA drug delivery systems for MDR solid tumors, including breast cancers, will be discussed.

Evaluation of mAb 2C5-modified dendrimer-based micelles for the co-delivery of siRNA and chemotherapeutic drug in xenograft mice model.

A combination therapy with small interfering RNA (siRNA) and chemotherapeutic drug is proven to be effective in downregulating the cancer resistance proteins, such as P-glycoprotein (P-gp). These proteins are involved in multidrug resistance (MDR) of tumors. MDR lowers the efficacy of chemotherapy and even renders it ineffective. A possible strategy to counteract the resistance is by downregulating the resistance proteins using siRNA. A targeted formulation capable of delivering siRNA and chemotherapeutic drug will not only downregulate P-gp but also increase the concentration of the chemotherapeutic drug at the site of tumor thereby increasing the therapeutic effect and lowering the systemic exposure. In this study, monoclonal antibody 2C5-modified dendrimer-based micelles were used to co-deliver siRNA and doxorubicin (DOX) to the tumor site in both male and female xenograft mice model. The nucleosome-specific 2C5 antibody recognizes the cancer cells via the cell-surface bound nucleosomes. The ability of the 2C5-modified formulation in affecting the metastasis of highly aggressive triple negative breast cancer (MDA-MB-231) was assessed via wound healing assay where the 2C5-modified formulation halved the rate at which the cells were migrating. Further, the therapeutic efficacy of the formulation was assessed by measuring the tumor volume progression where the 2C5-modified nanoparticle group had a similar tumor volume to the free drug group at the end of the study, although a 50% increase in DOX concentrations in blood was observed after the last dose of nanoparticle. Despite a higher DOX concentration and residence time we did not observe any systemic toxicities in the nanoparticle groups. The free drug group on the other hand showed body weight reduction as well as the visible irritation around the injection spot. The treatment group with 2C5-modified micelles has shown to be safe at the current dose of DOX and siRNA.The ability of 2C5 antibody-functionalized nanoparticles in delivering cargo to the tumor site in vivo was evaluated for DOX using ex vivo imaging and siRNA by western blot study to evaluate the levels of P-gp. Furthermore, the siRNA mediated P-gp downregualtion was studied using western blotting assay. We observed a 29% reduction of P-gp levels in both males and females with respect to the control (BHG). We also conclude that the dose of DOX and siRNA should be further optimized to have a better efficacy in a metastatic tumor model, which will be the subject of our future studies.

Recent Trends in Nanomedicine-Based Strategies to Overcome Multidrug Resistance in Tumors.

Cancer is the leading cause of economic and health burden worldwide. The commonly used approaches for the treatment of cancer are chemotherapy, radiotherapy, and surgery. Chemotherapy frequently results in undesirable side effects, and cancer cells may develop resistance. Combating drug resistance is a challenging task in cancer treatment. Drug resistance may be intrinsic or acquired and can be due to genetic factors, growth factors, the increased efflux of drugs, DNA repair, and the metabolism of xenobiotics. The strategies used to combat drug resistance include the nanomedicine-based targeted delivery of drugs and genes using different nanocarriers such as gold nanoparticles, peptide-modified nanoparticles, as well as biomimetic and responsive nanoparticles that help to deliver payload at targeted tumor sites and overcome resistance. Gene therapy in combination with chemotherapy aids in this respect. siRNA and miRNA alone or in combination with chemotherapy improve therapeutic response in tumor cells. Some natural substances, such as curcumin, quercetin, tocotrienol, parthenolide, naringin, and cyclosporin-A are also helpful in combating the drug resistance of cancer cells. This manuscript summarizes the mechanism of drug resistance and nanoparticle-based strategies used to combat it.

An update on dual targeting strategy for cancer treatment.

The key issue in the treatment of solid tumors is the lack of efficient strategies for the targeted delivery and accumulation of therapeutic cargoes in the tumor microenvironment (TME). Targeting approaches are designed for more efficient delivery of therapeutic agents to cancer cells while minimizing drug toxicity to normal cells and off-targeting effects, while maximizing the eradication of cancer cells. The highly complicated interrelationship between the physicochemical properties of nanoparticles, and the physiological and pathological barriers that are required to cross, dictates the need for the success of targeting strategies. Dual targeting is an approach that uses both purely biological strategies and physicochemical responsive smart delivery strategies to increase the accumulation of nanoparticles within the TME and improve targeting efficiency towards cancer cells. In both approaches, either one single ligand is used for targeting a single receptor on different cells, or two different ligands for targeting two different receptors on the same or different cells. Smart delivery strategies are able to respond to triggers that are typical of specific disease sites, such as pH, certain specific enzymes, or redox conditions. These strategies are expected to lead to more precise targeting and better accumulation of nano-therapeutics. This review describes the classification and principles of dual targeting approaches and critically reviews the efficiency of dual targeting strategies, and the rationale behind the choice of ligands. We focus on new approaches for smart drug delivery in which synthetic and/or biological moieties are attached to nanoparticles by TME-specific responsive linkers and advanced camouflaged nanoparticles.

Co-Delivery of siRNA and Chemotherapeutic Drug Using 2C5 Antibody-Targeted Dendrimer-Based Mixed Micelles for Multidrug Resistant Cancers.

Multidrug resistance (MDR) observed in tumors significantly hinders the efficacy of chemotherapy. Downregulation of efflux proteins, such as P-glycoprotein (P-gp), using small interfering RNA (siRNA) can be an effective way to minimize the resistance in tumors. In this study, monoclonal antibody 2C5 (mAb 2C5)-PEG7k-DOPE conjugates were post-inserted into the mixed dendrimer micelles containing generation 4 (G4) polyamidoamine (PAMAM)-PEG2k-DOPE and PEG5k-DOPE. The inherent amphiphilic nature of DOPE conjugates causes the copolymers to self-assemble to form a micelle, which can encapsulate hydrophobic chemotherapeutic drugs in its core. The siRNA electrostatically binds to the cationic charges on the G4 PAMAM dendrimer. The tumor-specific mAb 2C5 on the surface of these nano-preparations resulted in improved tumor targeting. This active targeting to tumors can cause increase in the drug and siRNA accumulation at the tumor site, and thereby minimizing the off-target effects. The micelles were shown to have higher cellular association and effectiveness in vitro. The immunomicelle preparation was also tested for cytotoxicity in breast (MDA-MB-231) and ovarian (SKOV-3TR) MDR cancer cell lines.

Investigation of Eutectic Mixtures of Fatty Acids as a Novel Construct for Temperature-Responsive Drug Delivery.

Background: Most of the traditional nanocarriers of cancer therapeutic moieties present dose-related toxicities due to the uptake of chemotherapeutic agents in normal body cells. The severe life-threatening effects of systemic chemotherapy are well documented. Doxorubicin, DOX is the most effective antineoplastic agent but with the least specific action that is responsible for severe cardiotoxicity and myelosuppression that necessitates careful monitoring while administering. Stimuli-sensitive/intelligent drug delivery systems, specifically those utilizing temperature as an external stimulus to activate the release of encapsulated drugs, have become a subject of recent research. Thus, it would be ideal to have a nanocarrier comprising safe excipients and controllable drug release capacity to deliver the drug at a particular site to minimize unwanted and toxic effects of chemotherapeutics. We have developed a simple temperature-responsive nanocarrier based on eutectic mixture of fatty acids. This study aimed to develop, physicochemically characterize and investigate the biological safety of eutectic mixture of fatty acids as a novel construct for temperature-responsive drug release potential. Methods: We have developed phase change material, PCM, based on a series of eutectic mixtures of fatty acids due to their unique and attractive physicochemical characteristics such as safety, stability, cost-effectiveness, and ease of availability. The reversible solid-liquid phase transition of PCM is responsible to hold firm or actively release the encapsulated drug. The eutectic mixtures of fatty acids (stearic acid and myristic acid) along with liquid lipid (oleic acid) were prepared to exhibit a tunable thermoresponsive platform. Doxorubicin-loaded lipid nanocarriers were successfully developed with combined hot melt encapsulation (HME) and sonication method and characterized to achieve enhanced permeability and retention (EPR) effect-based solid tumor targeting in response to exogenous temperature stimulus. The cytotoxicity against melanoma cell lines and in vivo safety studies in albino rats was also carried out. Results: Doxorubicin-loaded lipid nanocarriers have a narrow size distribution (94.59-219.3 nm), and a PDI (0.160-0.479) as demonstrated by photon correlation microscopy and excellent colloidal stability (Z.P value: -22.7 to -32.0) was developed. Transmission electron microscopy revealed their spherical morphology and characteristics of a monodispersed system. A biphasic drug release pattern with a triggered drug release at 41°C and 43°C and a sustained drug release was observed at 37°C. The thermoresponsive cytotoxic potential was demonstrated in B16F10 cancer cell lines. Hemolysis assay and acute toxicity studies with drug-free and doxorubicin lipid nanocarrier formulations provided evidence for their non-toxic nature. Conclusion: We have successfully developed a temperature-responsive tunable platform with excellent biocompatibility and intelligent drug release potential. The formulation components being from natural sources present superior characteristics in terms of cost, compatibility with normal body cells, and adaptability to preparation methods. The reported preparation method is adapted to avoid complex chemical processes and the use of organic solvents. The lipid nanocarriers with tunable thermoresponsive characteristics are promising biocompatible drug delivery systems for improved localized delivery of chemotherapeutic agents.

Liposomal Co-delivery of PD-L1 siRNA/Anemoside B4 for Enhanced Combinational Immunotherapeutic Effect.

Combination therapy has gained a lot of attention thanks to its superior activity against cancer. In the present study, we report a cRGD-targeted liposomal preparation for co-delivery of programmed cell death ligand 1 (PD-L1) small interfering RNA (siRNA) and anemoside B4 (AB4)─AB4/siP-c-L─and evaluate its anticancer efficiency in mouse models of LLC and 4T1 tumors. AB4/siP-c-L showed a particle size of (180.7 ± 7.3) nm and a ζ-potential of (32.8 ± 1.5) mV, with high drug encapsulation, pH-sensitive release properties, and good stability in serum. AB4/siP-c-L demonstrated prolonged blood circulation and increased tumor accumulation. Elevated cellular uptake was dependent on the targeting ligand cRGD. This combination induced significant tumor inhibition in LLC xenograft tumor-bearing mice by downregulating PD-L1 protein expression and modulating the immunosuppressive microenvironment. Liposomes favored the antitumor T-cell response with long-term memory, without obvious toxicity. A similar tumor growth inhibition was also demonstrated in the 4T1 tumor model. In summary, our results indicate that cRGD-modified and AB4- and PD-L1 siRNA-coloaded liposomes have potential as an antitumor preparation, and this approach may lay a foundation for the development of a new targeted drug delivery system.