Exploiting nanotechnology to overcome tumor drug resistance: Challenges and opportunities

Advancements in nanomedicine: Precision delivery strategies for male pelvic malignancies - Spotlight on prostate and colorectal cancer

BACKGROUND

Pelvic malignancies consistently pose significant global health challenges, adversely affecting the well-being of the male population. It is anticipated that clinicians will continue to confront these cancers in their practice. Nanomedicine offers promising strategies that revolutionize the treatment of male pelvic malignancies by providing precise delivery methods that aim to improve the efficacy of therapeutic outcomes while minimizing side effects. Nanoparticles are designed to encapsulate therapeutic agents and selectively target cancer cells. They can also be loaded with theragnostic agents, enabling multifunctional capabilities.

OBJECTIVE

This review aims to summarize the latest nanomedicine research into clinical applications, focusing on nanotechnology-based treatment strategies for male pelvic malignancies, encompassing chemotherapy, radiotherapy, immunotherapy, and other cutting-edge therapies. The review is structured to assist physicians, particularly those with limited knowledge of biochemistry and bioengineering, in comprehending the functionalities and applications of nanomaterials.

METHODS

Multiple databases, including PubMed, the National Library of Medicine, and Embase, were utilized to locate and review recently published articles on advancements in nano-drug delivery for prostate and colorectal cancers.

CONCLUSION

Nanomedicine possesses considerable potential in improving therapeutic outcomes and reducing adverse effects for male pelvic malignancies. Through precision delivery methods, this emerging field presents innovative treatment modalities to address these challenging diseases. Nevertheless, the majority of current studies are in the preclinical phase, with a lack of sufficient evidence to fully understand the precise mechanisms of action, absence of comprehensive pharmacotoxicity profiles, and uncertainty surrounding long-term consequences.

Current status and advances to improving drug delivery in diffuse intrinsic pontine glioma

Diffuse midline glioma (DMG), including tumors diagnosed in the brainstem (diffuse intrinsic pontine glioma - DIPG), is the primary cause of brain tumor-related death in pediatric patients. DIPG is characterized by a median survival of <12 months from diagnosis, harboring the worst 5-year survival rate of any cancer. Corticosteroids and radiation are the mainstay of therapy; however, they only provide transient relief from the devastating neurological symptoms. Numerous therapies have been investigated for DIPG, but the majority have been unsuccessful in demonstrating a survival benefit beyond radiation alone. Although many barriers hinder brain drug delivery in DIPG, one of the most significant challenges is the blood-brain barrier (BBB). Therapeutic compounds must possess specific properties to enable efficient passage across the BBB. In brain cancer, the BBB is referred to as the blood-brain tumor barrier (BBTB), where tumors disrupt the structure and function of the BBB, which may provide opportunities for drug delivery. However, the biological characteristics of the brainstem's BBB/BBTB, both under normal physiological conditions and in response to DIPG, are poorly understood, which further complicates treatment. Better characterization of the changes that occur in the BBB/BBTB of DIPG patients is essential, as this informs future treatment strategies. Many novel drug delivery technologies have been investigated to bypass or disrupt the BBB/BBTB, including convection enhanced delivery, focused ultrasound, nanoparticle-mediated delivery, and intranasal delivery, all of which are yet to be clinically established for the treatment of DIPG. Herein, we review what is known about the BBB/BBTB and discuss the current status, limitations, and advances of conventional and novel treatments to improving brain drug delivery in DIPG.

Acidic/hypoxia dual-alleviated nanoregulators for enhanced treatment of tumor chemo-immunotherapy

Chemotherapy plays a crucial role in triple-negative breast cancer (TNBC) treatment as it not only directly kills cancer cells but also induces immunogenic cell death. However, the chemotherapeutic efficacy was strongly restricted by the acidic and hypoxic tumor environment. Herein, we have successfully formulated PLGA-based nanoparticles concurrently loaded with doxorubicin (DOX), hemoglobin (Hb) and CaCO3 by a CaCO3-assisted emulsion method, aiming at the effective treatment of TNBC. We found that the obtained nanomedicine (DHCaNPs) exhibited effective drug encapsulation and pH-responsive drug release behavior. Moreover, DHCaNPs demonstrated robust capabilities in neutralizing protons and oxygen transport. Consequently, DHCaNPs could not only serve as oxygen nanoshuttles to attenuate tumor hypoxia but also neutralize the acidic tumor microenvironment (TME) by depleting lactic acid, thereby effectively overcoming the resistance to chemotherapy. Furthermore, DHCaNPs demonstrated a notable ability to enhance antitumor immune responses by increasing the frequency of tumor-infiltrating effector lymphocytes and reducing the frequency of various immune-suppressive cells, therefore exhibiting a superior efficacy in suppressing tumor growth and metastasis when combined with anti-PD-L1 (αPD-L1) immunotherapy. In summary, this study highlights that DHCaNPs could effectively attenuate the acidic and hypoxic TME, offering a promising strategy to figure out an enhanced chemo-immunotherapy to benefit TNBC patients.

In vitro activities and mechanisms of action of anti-cancer molecules from African medicinal plants: a systematic review

Cancer is one of the leading causes of death worldwide. In recent years, African countries have been faced with a rapid increase in morbidity and mortality due to this pathology. Management is often complicated by the high treatment costs, side effects and the increasing occurrence of resistance to treatments. The identification of new active ingredients extracted from endemic medicinal plants is definitively an interesting approach for the implementation of new therapeutic strategies: their extraction is often lower cost; their identification is based on an ethnobotanical history and a tradipratic approach; their use by low-income populations is simpler; this can help in the development of new synthetic molecules that are more active, more effective and with fewer side effects. The objective of this review is to document the molecules derived from African medicinal plants whose in vitro anti-cancer activities and the mechanisms of molecular actions have been identified. From the scientific databases Science Direct, PubMed and Google Scholar, we searched for publications on compounds isolated from African medicinal plants and having activity on cancer cells in culture. The data were analyzed in particular with regard to the cytotoxicity of the compounds and their mode of action. A total of 90 compounds of these African medicinal plants were selected. They come from nine chemical groups: alkaloids, flavonoids, polyphenols, quinones, saponins, steroids, terpenoids, xanthones and organic sulfides. These compounds have been associated with several cellular effects: i) Cytotoxicity, including caspase activation, alteration of mitochondrial membrane potential, and/or induction of reactive oxygen species (ROS); ii) Anti-angiogenesis; iii) Anti-metastatic properties. This review points out that the cited African plants are rich in active ingredients with anticancer properties. It also stresses that screening of these anti-tumor active ingredients should be continued at the continental scale. Altogether, this work provides a rational basis for the selection of phytochemical compounds for use in clinical trials.

Overcoming multidrug resistance by reversan and exterminating glioblastoma and glioblastoma stem cells by delivering drug-loaded nanostructure hybrid lipid capsules (nHLCs)

Glioblastoma multiforme (GBM) is regarded as a highly aggressive brain cancer with a poor prognosis. There is an increase in the expression of P-glycoprotein (P-gp), responsible for multidrug resistance (MDR), making it a potential target for improving drug responses. Additionally, glioblastoma stem cells (GSCs) increase resistance to chemo- and radiotherapy and play a major role in cancer relapse. In this study, we targeted P-gp using a small molecule inhibitor, reversan (RV), to inhibit MDR that prolonged the retention of drugs in the cytosolic milieu. To eliminate GBM and GSCs, we have used two well-established anti-cancer drugs, regorafenib (RF) and curcumin (CMN). To improve the pharmacokinetics and decrease systemic delivery of drugs, we developed nanostructure hybrid lipid capsules (nHLCs), where hydrophobic drugs can be loaded in the core, and their physicochemical properties were determined by dynamic light scattering (DLS) and cryo-scanning electron microscopy (SEM). Inhibition of MDR by RV has also shown enhanced retention of nHLC in GBM cells. Co-delivery of drug-loaded nHLCs, pre-treated with RV, exhibited superior cytotoxicity in both GBM and GSCs than their individual doses and effectively reduced the size and stemness of tumor spheres and accelerated the rate of apoptosis, suggesting a promising treatment for glioblastoma.

Delivery of gefitinib loaded nanoparticles for effectively inhibiting prostate cancer progression

Androgen deprivation therapy is administered to suppress the growth of prostate cancer (PCa). However, some cells continue to proliferate independent of hormones, leading to the development of castration-resistant prostate cancer (CRPC). Overexpression of the epidermal growth factor receptor (EGFR) has been observed in CRPC and is associated with an unfavorable prognosis. Gefitinib (GEF) is an EGFR inhibitor used to treat patients with CRPC. Nevertheless, some clinical studies have reported that gefitinib does not result in prostate-specific antigen (PSA) or objectively measurable CRPC reactions. This lack of response may be attributed to the limited solubility in water, high side effects, low tumor aggregation, and insufficient tumor-specific reactions of GEF. In order to tackle these obstacles, we present a practical and efficient approach to administer GEF, encompassing the utilization of biocompatible nanostructures as a vehicle for drug delivery to augment its bioaccessibility and curative potency. Despite their small particle size, poly(D,L-lactide-co-glycolide) acid nanoparticles (PLGA NPs) exhibit a high drug-loading capacity, low toxicity, biocompatibility, biodegradability, and minimal immunogenicity. The drug delivery efficiency can be improved by employing GEF@PLGA NPs, which could also enhance drug cytotoxicity and impede the advancement of prostate cancer. Moreover, through experiments in vivo, it has been verified that GEF@PLGA NPs exhibit selective accumulation in the tumor and effectively restrain tumor growth. Therefore, the GEF@PLGA NPs hold great promise for the treatment of PCa.

Reversal mechanism of multidrug-resistant cancer cells by lectin as chemo-adjuvant and targeted therapy- a systematic review

BACKGROUND

Cancer is characterized as the leading cause of death, and the susceptibility of cancer cells to develop resistance due to long-term exposure to complementary chemotherapeutic treatment is referred to as multidrug resistance cancer cells (MDRC), which is a significant obstacle in the treatment of malignancies. Since complementary medicine lost its effectiveness, the development of potential alternative and novel therapeutic approaches has been elevated to a top priority in recent years. In this context, a bioactive protein lectin from plant and animal sources exhibits an invaluable source of anticancer agents with vast therapeutic potential.

PURPOSE

This manuscript's primary purpose is to enlighten the evidence-based (from 1986 to 2022) possible molecular mechanism of alternative treatment approaches using lectins over the complementary medicines used for cancer treatment.

METHODS

The PRISMA rules have been followed properly and qualitative and quantitative data are synthesized systematically. Articles were identified based on Clinical and preclinical reports published on lectin that investigated the in-depth cellular mechanisms, of reverse drug integrative oncology, as a nano-carried targeted delivery. Articles were systematically screened from 1986 to 2022 and selected based on electronic database searches, Medline (PubMed), Google Scholar, Web of Science, Encyclopaedias, Scopus, and ClinicalTrials.gov database.

RESULTS

The search turned up 4,212 publications from 38 different nations, of which 170 reference articles were used in our analysis, in 16 combination therapy and their mode of action, and 27 clinical trial studies including dosage and mechanism of action were included. Reports from the 30 lectins belonging to 28 different families have been included. The reversal mechanism of lectin and alternative therapy against MDRC is critically screened and according to a few clinical and preclinical reports, lectin can suppress the overexpressing genes like P-53, EGFR, and P-gp, MRP, and ABC transporter proteins associated with intracellular transportation of drugs. Since, the drug efflux mechanism leads to MDRC, in this phenomenon, lectin plays a key role in reversing the efflux mechanism. Few preclinical reports have mentioned that lectin shows synergism in combination with complementary medicine and as a nano drug carrier helps to deliver to the targeted site.

CONCLUSION

We have discussed the alternative therapy using lectin and an in-depth insight into the reversal drug resistance mechanisms to combat MDRC cancer, enhance the efficacy, reduce toxicity and adverse events, and ensure targeted delivery, and their application in the field of cancer diagnosis and prognosis has been discussed. However, further investigation is necessary in drug development and clinical trials which could be helpful to elaborate the reversal mechanism and unlock newer treatment modalities in MDRC cancer.

A detailed insight of the tumor targeting using nanocarrier drug delivery system

Human struggle against the deadly disease conditions is continued since ages. The contribution of science and technology in fighting against these diseases cannot be ignored exclusively due to the invention of novel procedure and products, extending their size ranges from micro to nano. Recently nanotechnology has been gaining more consideration for its ability to diagnose and treat different cancers. Different nanoparticles have been used to evade the issues related with conservative anticancer delivery systems, including their nonspecificity, adverse effects and burst release. These nanocarriers including, solid lipid nanoparticles (SLNs), liposomes, nano lipid carriers (NLCs), nano micelles, nanocomposites, polymeric and magnetic nanocarriers, have brought revolutions in antitumor drug delivery. Nanocarriers improved the therapeutic efficacy of anticancer drugs with better accumulation at the specific site with sustained release, improved bioavailability and apoptosis of the cancer cells while bypassing the normal cells. In this review, the cancer targeting techniques and surface modification on nanoparticles are discussed briefly with possible challenges and opportunities. It can be concluded that understanding the role of nanomedicine in tumor treatment is significant, and therefore, the modern progressions in this arena is essential to be considered for a prosperous today and an affluent future of tumor patients.

Rationally Designed Naringenin-Conjugated Polyester Nanoparticles Enable Folate Receptor-Mediated Peroral Delivery of Insulin

Receptor-mediated transcytosis of nanoparticles is paramount for the effective delivery of various drugs. Here, we report the design and synthesis of highly functional nanoparticles with specific targeting toward the folate receptor (FR) for the peroral delivery of insulin. In doing so, we demonstrate naringenin (NAR), a citrous flavonoid, as a targeting ligand to FR, with a similar affinity as folic acid. The NAR-decorated nanoparticles indicated a 4-fold increase in FR colocalization compared to unfunctionalized nanoparticles. The NAR-conjugated precision polyester allows for high insulin loading and entrapment efficiencies. As a result, insulin-laden NAR-functional nanoparticles offered a 3-fold higher bioavailability in comparison to unfunctionalized nanoparticles. This work generated a promising contribution to folate-receptor-mediated peroral delivery of insulin, utilizing polymeric nanoparticles decorated with a natural ligand, NAR.

Anti-cancer effect of fenbendazole-incorporated PLGA nanoparticles in ovarian cancer

OBJECTIVE

Fenbendazole (FZ) has potential anti-cancer effects, but its poor water solubility limits its use for cancer therapy. In this study, we investigated the anti-cancer effect of FZ with different drug delivery methods on epithelial ovarian cancer (EOC) in both in vitro and in vivo models.

METHODS

EOC cell lines were treated with FZ and cell proliferation was assessed. The effect of FZ on tumor growth in cell line xenograft mouse model of EOC was examined according to the delivery route, including oral and intraperitoneal administration. To improve the systemic delivery of FZ by converting fat-soluble drugs to hydrophilic, we prepared FZ-encapsulated poly(D,L-lactide-co-glycolide) acid (PLGA) nanoparticles (FZ-PLGA-NPs). We investigated the preclinical efficacy of FZ-PLGA-NPs by analyzing cell proliferation, apoptosis, and in vivo models including cell lines and patient-derived xenograft (PDX) of EOC.

RESULTS

FZ significantly decreased cell proliferation of both chemosensitive and chemoresistant EOC cells. However, in cell line xenograft mouse models, there was no effect of oral FZ treatment on tumor reduction. When administered intraperitoneally, FZ was not absorbed but aggregated in the intraperitoneal space. We synthesized FZ-PLGA-NPs to obtain water solubility and enhance drug absorption. FZ-PLGA-NPs significantly decreased cell proliferation in EOC cell lines. Intravenous injection of FZ-PLGA-NP in xenograft mouse models with HeyA8 and HeyA8-MDR significantly reduced tumor weight compared to the control group. FZ-PLGA-NPs showed anti-cancer effects in PDX model as well.

CONCLUSION

FZ-incorporated PLGA nanoparticles exerted significant anti-cancer effects in EOC cells and xenograft models including PDX. These results warrant further investigation in clinical trials.

Polydopamine-containing nano-systems for cancer multi-mode diagnoses and therapies: A review

Polydopamine (PDA) has fascinating properties such as inherent biocompatibility, simple preparation, strong near-infrared absorption, high photothermal conversion efficiency, and strong metal ion chelation, which have catalyzed extensive research in PDA-containing multifunctional nano-systems particularly for biomedical applications. Thus, it is imperative to overview synthetic strategies of various PDA-containing nanoparticles (NPs) for state-of-the-art cancer multi-mode diagnoses and therapies applications, and offer a timely and comprehensive summary. In this review, we will focus on the synthetic approaches of PDA NPs, and summarize the construction strategies of PDA-containing NPs with different structure forms. Additionally, the application of PDA-containing NPs in bioimaging such as photoacoustic imaging, fluorescence imaging, magnetic resonance imaging and other imaging modalities will be reviewed. We will especially offer an overview of their therapeutic applications in tumor chemotherapy, photothermal therapy, photodynamic therapy, photocatalytic therapy, sonodynamic therapy, radionuclide therapy, gene therapy, immunotherapy and combination therapy. At the end, the current trends, limitations and future prospects of PDA-containing nano-systems will be discussed. This review aims to provide guidelines for new scientists in the field of how to design PDA-containing NPs and what has been achieved in this area, while offering comprehensive insights into the potential of PDA-containing nano-systems used in cancer diagnosis and treatment.

Nano-engineering nanomedicines with customized functions for tumor treatment applications

Nano-engineering with unique "custom function" capability has shown great potential in solving technical difficulties of nanomaterials in tumor treatment. Through tuning the size and surface properties controllablly, nanoparticles can be endoewd with tailored structure, and then the characteristic functions to improve the therapeutic effect of nanomedicines. Based on nano-engineering, many have been carried out to advance nano-engineering nanomedicine. In this review, the main research related to cancer therapy attached to the development of nanoengineering nanomedicines has been presented as follows. Firstly, therapeutic agents that target to tumor area can exert the therapeutic effect effectively. Secondly, drug resistance of tumor cells can be overcome to enhance the efficacy. Thirdly, remodeling the immunosuppressive microenvironment makes the therapeutic agents work with the autoimmune system to eliminate the primary tumor and then prevent tumor recurrence and metastasis. Finally, the development prospects of nano-engineering nanomedicine are also outlined.

Ligand Chemistry in Antitumor Theranostic Nanoparticles

ConspectusTheranostic nanoparticles' potential in tumor treatment has been widely acknowledged thanks to their capability of integrating multifaceted functionalities into a single nanosystem. Theranostic nanoparticles are typically equipped with an inorganic core with exploitable physical properties for imaging and therapeutic functions, bioinert coatings for improved biocompatibility and immunological stealth, controlled drug-loading-release modules, and the ability to recognize specific cell type for uptake. Integrating multiple functionalities in a single nanosized construct require sophisticated molecular design and precise execution of assembly procedures. Underlying the multifunctionality of theranostic nanoparticles, ligand chemistry plays a decisive role in translating theoretical designs into fully functionalized theranostic nanoparticles. The ligand hierarchy in theranostic nanoparticles is usually threefold. As they serve to passivate the nanoparticle's surface, capping ligands form the first layer directly interfacing with the crystalline lattice of the inorganic core. The size and shape of nanoparticles are largely determined by the molecular property of capping ligands so that they have profound influences on the nanoparticles' surface chemistry and physical properties. Capping ligands are mostly chemically inert, which necessitates the presence of additional ligands for drug loading and tumor targeting. The second layer is commonly utilized for drug loading. Therapeutic drugs can either be covalently conjugated onto the capping layer or noncovalently loaded onto nanoparticles via drug-loading ligands. Drug-loading ligands need to be equally versatile in properties to accommodate the diversity of drugs. Biodegradable moieties are often incorporated into drug-loading ligands to enable smart drug release. With the aid of targeting ligands which usually stand the tallest on the nanoparticle surface to seek and bind to their corresponding receptors on the target, theranostic nanoparticles can preferentially accumulate at the tumor site to attain a higher precision and quantity for drug delivery. In this Account, the properties and utilities of representative capping ligands, drug-loading ligands, and targeting ligands are reviewed. Since these types of ligands are often assembled in close vicinity to each other, it is essential for them to be chemically compatible and able to function in tandem with each other. Relevant conjugation strategies and critical factors with a significant impact on ligands' performance on nanoparticles are discussed. Representative theranostic nanoparticles are presented to showcase how different types of ligands function synergistically from a single nanosystem. Finally, the technological outlook of evolving ligand chemistry on theranostic nanoparticles is provided.

Liposomes in Cancer Therapy: How Did We Start and Where Are We Now

Since their first discovery in the 1960s by Alec Bangham, liposomes have been shown to be effective drug delivery systems for treating various cancers. Several liposome-based formulations received approval by the U.S. Food and Drug Administration (FDA) and European Medicines Agency (EMA), with many others in clinical trials. Liposomes have several advantages, including improved pharmacokinetic properties of the encapsulated drug, reduced systemic toxicity, extended circulation time, and targeted disposition in tumor sites due to the enhanced permeability and retention (EPR) mechanism. However, it is worth noting that despite their efficacy in treating various cancers, liposomes still have some potential toxicity and lack specific targeting and disposition. This explains, in part, why their translation into the clinic has progressed only incrementally, which poses the need for more research to focus on addressing such translational limitations. This review summarizes the main properties of liposomes, their current status in cancer therapy, and their limitations and challenges to achieving maximal therapeutic efficacy.

Prospects for hypoxia-based drug delivery platforms for the elimination of advanced metastatic tumors: From 3D modeling to clinical concepts

Hypoxia is a unique characteristic of the solid tumor microenvironment. Hypoxia contributes to multi-drug resistance, metastasis and cancer relapse through numerous molecular pathways, but at the same time provides an opportunity for the development of novel drugs or modalities specifically targeting hypoxic tumor regions. Given the high significance of tumor hypoxia in therapeutic results, we here discuss a variety of hypoxia-adopted strategies, and their potential and utility in the treatment of deep-seated hypoxic tumor cells. We discuss the merits and demerits of these approaches, as well as their combination with other approaches such as photodynamic therapy. We also survey the currently available 3D hypoxia modeling systems, in particular organoid-based microfluidics. Finally, we discuss the potential and the current status of preclinical tumor hypoxia approaches in clinical trials for advanced cancer. We believe that multi-modal imaging and therapeutic hypoxia adopted drug delivery platforms could provide better efficacy and safety profiles, and more importantly personalized therapy. Determining the hypoxia status of tumors could offer a second chance for the clinical translation of hypoxia-based agents, such as hypoxia activated prodrugs (HAPs) from bench to bedside.

Chemotherapeutic Potential of Saikosaponin D: Experimental Evidence

Saikosaponin D (SSD), an active compound derived from the traditional plant Radix bupleuri, showcases potential in disease management owing to its antioxidant, antipyretic, and anti-inflammatory properties. The toxicological effects of SSD mainly include hepatotoxicity, neurotoxicity, hemolysis, and cardiotoxicity. SSD exhibits antitumor effects on multiple targets and has been witnessed in diverse cancer types by articulating various cell signaling pathways. As a result, carcinogenic processes such as proliferation, invasion, metastasis, and angiogenesis are inhibited, whereas apoptosis, autophagy, and differentiation are induced in several cancer cells. Since it reduces side effects and strengthens anti-cancerous benefits, SSD has been shown to have an additive or synergistic impact with chemo-preventive medicines. Regardless of its efficacy and benefits, the considerations of SSD in cancer prevention are absolutely under-researched due to its penurious bioavailability. Diverse studies have overcome the impediments of inadequate bioavailability using nanotechnology-based methods such as nanoparticle encapsulation, liposomes, and several other formulations. In this review, we emphasize the association of SSD in cancer therapeutics and the discussion of the mechanisms of action with the significance of experimental evidence.

The past, present, and future of chemotherapy with a focus on individualization of drug dosing

While there have been rapid advances in developing new and more targeted drugs to treat cancer, much less progress has been made in individualizing dosing. Even though the introduction of immunotherapies such as CAR T-cells and checkpoint inhibitors, as well as personalized therapies that target specific mutations, have transformed clinical treatment of cancers, chemotherapy remains a mainstay in oncology. Chemotherapies are typically dosed on either a body surface area (BSA) or weight basis, which fails to account for pharmacokinetic differences between patients. Drug absorption, distribution, metabolism, and excretion rates can vary between patients, resulting in considerable differences in exposure to the active drugs. These differences result in suboptimal dosing, which can reduce efficacy and increase side-effects. Therapeutic drug monitoring (TDM), genotype guided dosing, and chronomodulation have been developed to address this challenge; however, despite improving clinical outcomes, they are rarely implemented in clinical practice for chemotherapies. Thus, there is a need to develop interventions that allow for individualized drug dosing of chemotherapies, which can help maximize the number of patients that reach the most efficacious level of drug in the blood while mitigating the risks of underdosing or overdosing. In this review, we discuss the history of the development of chemotherapies, their mechanisms of action and how they are dosed. We discuss substantial intraindividual and interindividual variability in chemotherapy pharmacokinetics. We then propose potential engineering solutions that could enable individualized dosing of chemotherapies, such as closed-loop drug delivery systems and bioresponsive biomaterials.

Microbial Polysaccharide-Based Nanoformulations for Nutraceutical Delivery

In recent times, nutrition and diet have become prominent health paradigms due to sedentary lifestyle disorders. Preventive health care strategies are becoming increasingly popular instead of treating and managing diseases. A nutraceutical is an innovative concept that offers additional health benefits beyond its fundamental nutritional value. These nutraceuticals have the potential to reduce the exorbitant use of synthetic drugs because the modern medicine approach of treating diseases with high-tech, expensive supplements, and long-term consequences aggravates consumers. However, most nutraceuticals are plant-derived, making them susceptible to degradation and prone to chemical instability, poor solubility, unpleasant taste, and bioactivity loss before absorption to the targeted site. To counteract this problem, the bioavailability of these labile compounds can be maximized by encapsulating them in protective nanocarriers. It is crucial that nanoencapsulation technologies convert bioactive compounds into forms that can be easily combined with functional foods and beverages without adversely affecting their organoleptic properties. In recent years, nanoformulations using food-grade materials, such as polysaccharides, proteins, lipids, etc., have received considerable attention. Among them, microbial polysaccharides are biocompatible, nontoxic, and nonimmunogenic, and most of them are US-FDA approved and can undergo tailored modifications. The nanoformulation of microbial polysaccharide is a relatively new frontier which has several advantages over existing systems. The present article, for the first time, comprehensively reviews microbial polysaccharides-based nanodelivery systems for nutraceuticals and discusses various techno-commercial aspects of these nanotechnological preparations. Moreover, this has also attempted to draw a future research perspective in this area.

Superiority of biomimetic micelle-entrapped nanoporous silica xerogel to deliver poorly water-soluble itraconazole

Micelle-entrapped silica xerogel (M-Silica xerogel) was biomimetically synthesized to combine the advantages of micelles and silica xerogel to load poorly water-soluble drug itraconazole (ITZ). Tween 20, tween 40, and tween 80 were applied to prepare micelles as the templates for M20-Silica xerogel, M40-Silica xerogel, and M80-Silica xerogel, respectively. During the silica frame construction, the surfactant formed a micelle as the porous template, silicon hydroxyl groups interacted with the hydrophilic parts of the micelle, and polyethylenimine catalyzed silica polycondensation owing to its amino groups, resulting in the formation of the M-Silica xerogels. The results showed that the particle size of the sub-particles from the M40-Silica xerogel was larger than from the M20-Silica xerogel, and the M80-Silica xerogel was the largest among these three samples, demonstrating that the emulsifying ability had a direct impact on the particle size of the M-Silica xerogel. The M-Silica xerogel had a large pore size in the range of 10-50 nm. Small mesopores (2-5 nm) dominated the pore size of the M20-Silica xerogel, while medium mesopores (5-10 nm) occupied most the pore distribution of the M40-Silica xerogel, and large mesopores (10-50 nm) shouldered most the pore distribution for the M80-Silica xerogel. Among these three drug-loaded carriers, the M40-Silica xerogel with the largest amount of medium mesopores presented the best ITZ-release behavior, demonstrating that medium mesopores facilitated drug release, while small mesopores impeded drug release and large mesopores were not favorable to retaining amorphous drugs in the pores.

Preparation of antibacterial Zn and Ni substituted cobalt ferrite nanoparticles for efficient biofilm eradication

Zinc (Zn) and, alternatively, nickel (Ni) substituted cobalt ferrite (CF) nanoparticles (NPs) were prepared by sol-gel method. X-ray diffraction analysis revealed the formation of cubic structure of cobalt ferrite. FTIR analysis confirmed the vibrational band located at 550-580 cm^-1 that belongs to the M - O bond (M = Ni, and Zn). The alteration of the surface morphology of CF after the addition of Zn and Ni ions was observed from scanning electron microscopic images. The additional peaks in the energy dispersive X-ray diffraction (EDX) analysis spectra were found to correspond to Zn and Ni. The presence of Zn and, alternatively, Ni ions enhanced the biocidal properties of CF NPs against gram negative organisms, in a concentration and time-dependent manner. Furthermore, exposure to CF, CF-Zn and CF-Ni NPs decreased metabolic activity due to the damage of extra polymorphic substances, live/dead cell variation, architecture and surface integrity of the cells. Altogether, the present investigation provides the basis of metal ion substituted metal oxide NPs as anti-biofilm agents against gram-positive and gram-negative bacteria.

Approaches to minimize the effects of P-glycoprotein in drug transport: A review

P-glycoprotein (P-gp) is a transporter protein that is come under the ATP binding cassette family of proteins. It is situated on the surface of the intestine epithelium, where P-gp substrate binds to the transporter and is pumped into the intestine lumen by the ATP-driven energy-dependent process. In this review, we summarize the role of the P-gp efflux transporter situated on the intestine, the clinical importance of P-gp related drug interactions, and approaches to minimize the effect of P-gp in drug transport. This review also focuses on the impact of P-gp on the bioavailability of the orally administered drug. Many drug's oral bioavailabilities can improve by concomitant use of P-gp inhibitors. Multidrug resistance are reduced by using some naturally occurring compounds obtained from plants and several synthetic P-gp inhibitors. Formulation strategies, one of the most important approaches to mimic the P-gp transporter's action, finally enhancing the oral bioavailability of the drug by inhibiting its P-gp efflux. Vitamin E TPGS, Gelucire 44/14 and other pharmaceutical/formulation excipients inhibit the P-gp efflux. A prodrug approach might be a useful strategy to overcome drug resistance. Prodrug helps to enhance the solubility or alter the pharmacokinetic properties but does not diminish the pharmacological action.

Construction of an exosome-functionalized graphene oxide based composite bionic smart drug delivery system and its anticancer activity

Graphene oxide has covalently modified by chito oligosaccharides andγ-polyglutamic acid to form GO-CO-γ-PGA, which exhibits excellent performance as a drug delivery carrier, but this carrier did not have the ability to actively target. In this study, the targeting property of breast cancer tumor cell exosomes was exploited to give GO-CO-γ-PGA the ability to target breast tumor cells (MDA-MB-231), and the drug mitoxantrone (MIT) was loaded to finally form EXO-GO-CO-γ-PGA-MIT with an encapsulation efficiency of 73.02%. The pH response of EXO-GO-CO-γ-PGA showed a maximum cumulative release rate of 56.59% (pH 5.0, 120 h) and 6.73% (pH 7.4, 120 h) for MIT at different pH conditions.In vitrocellular assays showed that EXO-GO-CO-γ-PGA-MIT was more potent in killing MDA-MB-231 cells due to its targeting ability and had a significantly higher pro-apoptotic capacity compared to GO-CO-γ-PGA-MIT. The results showed that this bionic nano-intelligent drug delivery system has good drug slow release function and it can increase the local drug concentration of tumor and enhance the pro-apoptotic ability of MIT, so this newly synthesized bionic drug delivery carriers (EXO-GO-CO-γ-PGA-MIT) has potential application in breast cancer treatment.

Research advances in the role and pharmaceuticals of ATP-binding cassette transporters in autoimmune diseases

Autoimmune diseases are caused by the immune response of the body to its antigens, resulting in tissue damage. The pathogenesis of these diseases has not yet been elucidated. Most autoimmune diseases cannot be cured by effective drugs. The treatment strategy is to relieve the symptoms of the disease and balance the body's autoimmune function. The abnormal expression of ATP-binding cassette (ABC) transporters is directly related to the pathogenesis of autoimmune diseases and drug therapy resistance, which poses a great challenge for the drug therapy of autoimmune diseases. Therefore, this paper reviews the interplay between ABC transporters and the pathogenesis of autoimmune diseases to provide research progress and new ideas for the development of drugs in autoimmune diseases.

Hypoxia-Activated Fluorescent Probe Based on Self-Immolative Block Copolymer

This work reports a hypoxia-activated fluorescent probe for tumor imaging by using self-immolative block copolymer with azobenzene linkage. The water-soluble polymer composed of self-immolative building blocks shows no obvious fluorescence. Under the hypoxic microenvironment of tumor cells, the azobenzene is reduced by the overexpressed azoreductase, which will trigger a domino-like disassembly of the self-immolative polymer. The released building blocks from the self-immolative polymer emit strong fluorescence, which shows the potential application in tumor imaging.

Co-delivery of doxorubicin and SIS3 by folate-targeted polymeric micelles for overcoming tumor multidrug resistance

Multidrug resistance (MDR) is considered as a critical limiting factor for the successful chemotherapy, which is mainly characterized by the overexpression of ATP-binding cassette (ABC) transporter ABCB1 or ABCG2. In this study, folate-targeted polymeric micellar carrier was successfully constructed to co-delivery of doxorubicin (DOX) and SIS3 (FA/DOX/SIS3 micelles), a specific Smad3 inhibitor which sensitizes ABCB1- and ABCG2-overexpressing cancer cells to chemotherapeutic agents. The ratio of DOX to SIS3 in polymeric micelles was determined based on the anti-tumor activity against resistant breast cells. In addition, FA/DOX/SIS3 micelles exhibited a much longer circulation time in blood and were preferentially accumulated in resistant tumor tissue. Pharmacodynamic studies showed that FA/DOX/SIS3 micelles possessed superior anti-tumor activity than other DOX-based treatments. Overall, FA/DOX/SIS3 micelles are a promising formulation for the synergistic treatment of drug-resistant tumor.

C1632 suppresses the migration and proliferation of non-small-cell lung cancer cells involving LIN28 and FGFR1 pathway

Chemoresistance and migration represent major obstacles in the therapy of non‐small‐cell lung cancer (NSCLC), which accounts for approximately 85% of lung cancer patients in clinic. In the present study, we report that the compound C1632 is preferentially distributed in the lung after oral administration in vivo with high bioavailability and limited inhibitory effects on CYP450 isoenzymes. We found that C1632 could simultaneously inhibit the expression of LIN28 and block FGFR1 signalling transduction in NSCLC A549 and A549R cells, resulting in significant decreases in the phosphorylation of focal adhesion kinase and the expression of matrix metalloproteinase‐9. Consequently, C1632 effectively inhibited the migration and invasion of A549 and A549R cells. Meanwhile, C1632 significantly suppressed the cell viability and the colony formation of A549 and A549R cells by inhibiting DNA replication and inducing G0/G1 cell cycle arrest. Interestingly, compared with A549 cells, C1632 possesses the same or even better anti‐migration and anti‐proliferation effects on A549R cells, regardless of drug resistance. In addition, C1632 also displayed the capacity to inhibit the growth of A549R xenograft tumours in mice. Altogether, these findings reveal the potential of C1632 as a promising anti‐NSCLC agent, especially for chemotherapy‐resistant NSCLC treatment.

Injectable hydrogel for postoperative synergistic photothermal-chemodynamic tumor and anti-infection therapy

Tumor surgery is usually accompanied by neoplasm residual, tissue defects, and multi-drug resistant bacterial infection, causing high tumor recurrence, low survival rate, and chronic wounds. Herein, a light-activated injectable hydrogel based on bioactive nanocomposite system is developed by incorporating Ag₂S nanodots conjugated Fe-doped bioactive glass nanoparticles (BGN-Fe-Ag₂S) into biodegradable PEGDA and AIPH solution for inhibiting tumor growth, treating bacterial infection, and promoting wound healing. Under laser irradiation, the photothermal effect mediated by Ag₂S nanodots would trigger the decomposition of AIPH, generating alkyl radicals to initiate the gelation of PEGDA. The in-situ gelatinized hydrogel, with outstanding photothermal effect and chemodynamic effect derived from the doped Fe in BGN-Fe-Ag₂S, can not only eliminate multidrug-resistant bacteria but also efficiently ablated tumor during treatment. Moreover, the hydrogel significantly accelerated wound healing with more skin appendages in the full-thickness cutaneous wounds model because of the hydrolysis of bioactive glass. These results manifest that this multifunctional hydrogel is a suitable biomaterial to inhibit tumor proliferation and overcome tissue bacterial infection after surgical removal of tumors.

Saikosaponin D: review on the antitumour effects, toxicity and pharmacokinetics

CONTEXT

Bupleuri Radix, the dried root of Bupleurum chinense DC and Bupleurum scorzonerifolium Willd (Apiaceae), is an important medicinal herb widely used to treat cancers for hundreds of years in Asian countries. As the most antitumour component but also the main toxic component in Bupleuri Radix, saikosaponin D (SSD) has attracted extensive attention. However, no summary studies have been reported on the antitumour effects, toxicity and pharmacokinetics of this potential natural anticancer substance.

OBJECTIVE

To analyse and summarise the existing findings regarding to the antitumour effects, toxicity and pharmacokinetics of SSD.

MATERIALS AND METHODS

We collected relevant information published before April 2021 by conducting a search of literature available in various online databases including PubMed, Science Direct, CNKI, Wanfang database and the Chinese Biological Medicine Database. Bupleurum, Bupleuri Radix, saikosaponin, saikosaponin D, tumour, toxicity, and pharmacokinetics were used as the keywords.

RESULTS

The antitumour effects of SSD were multi-targeted and can be realised through various mechanisms, including inhibition of proliferation, invasion, metastasis and angiogenesis, as well as induction of cell apoptosis, autophagy, and differentiation. The toxicological effects of SSD mainly included hepatotoxicity, neurotoxicity, haemolysis and cardiotoxicity. Pharmacokinetic studies demonstrated that SSD had the potential to alter the pharmacokinetics of some drugs for its influence on CYPs and P-gp, and the oral bioavailability and actual pharmacodynamic substances in vivo of SSD are still controversial.

CONCLUSIONS

SSD is a potentially effective and relatively safe natural antitumour substance, but more research is needed, especially in vivo antitumour effects and pharmacokinetics of the compound.

Fibrinolytic nanocages dissolve clots in the tumor microenvironment, improving the distribution and therapeutic efficacy of anticancer drugs

Fibrin, one of the components of the extracellular matrix (ECM), acts as a transport barrier within the core of tumors by constricting the blood vessels and forming clots, leading to poor intratumoral distribution of anticancer drugs. Our group previously developed a microplasmin-based thrombolytic ferritin nanocage that efficiently targets and dissolves clots without causing systemic fibrinolysis or disrupting hemostatic clots. We hypothesized that the thrombolytic nanocage-mediated degradation of fibrin clots in the tumor ECM can lead to enhanced intratumoral drug delivery, especially for nanosized anticancer drugs. Fibrin clot deposition worsens after surgery and chemotherapy, further hindering drug delivery. Moreover, the risk of venous thromboembolism (VTE) also increases. Here, we used thrombolytic nanocages with multivalent clot-targeting peptides and fibrin degradation enzymes, such as microplasmin, to dissolve fibrin in the tumor microenvironment and named them fibrinolytic nanocages (FNCs). These FNCs target tumor clots specifically and effectively. FNCs efficiently dissolve fibrin clots inside of the tumor vessels, suggesting that they can mitigate the risk of VTE in cancer patients. Coadministration of FNC and doxorubicin led to improved chemotherapeutic activity in a syngeneic mouse melanoma model. Furthermore, the FNCs increased the distribution of Doxil/doxorubicin nanoparticles within mouse tumors. These results suggest that fibrinolytic cotherapy might help improve the therapeutic efficacy of anticancer nanomedicines. Thus, microplasmin-based fibrinolytic nanocages are promising candidates for this strategy due to their hemostatic safety and ability to home in on the tumor.

Targeted Photodynamic Therapy Using Alloyed Nanoparticle-Conjugated 5-Aminolevulinic Acid for Breast Cancer

Photodynamic therapy (PDT) has been investigated as an effective, non-invasive, and alternative tumor-ablative therapy that uses photosensitizers (PSs) and safe irradiation light in the presence of oxygen to generate reactive oxygen species (ROS) to kill malignant cancer cells. However, the off-target activation of the PSs can hinder effective PDT. Therefore, an advanced drug delivery system is required to selectively deliver the PS to the therapeutic region only and reduce off-target side effects in cancer treatment. The integration of laser-initiated PDT with nanotechnology has provided new opportunities in cancer therapy. In this study, plasmonic bimetallic nanoparticles (NPs) were prepared for the targeted PDT (TPDT) of in vitro cultured MCF-7 breast cancer cells. The NPs were functionalized with PEG through Au–thiol linkage to enhance their biocompatibility and subsequently attached to the PS precursor 5-aminolevulinic acid via electrostatic interactions. In order to enhance specific targeting, anti-HER-2 antibodies (Ab) were decorated onto the surface of the nanoconjugate (NC) to fabricate a 5-ALA/Au–Ag-PEG-Ab NC. In vitro studies showed that the synthesized NC can enter MCF-7 cells and localize in the cytoplasm to metabolize 5-ALA to protoporphyrin IX (PpIX). Upon light irradiation, PpIX can efficiently produce ROS for the PDT treatment of MCF-7. Cellular viability studies showed a decrease from 49.8% ± 5.6 ** to 13.8% ± 2.0 *** for free 5-ALA versus the NC, respectively, under equivalent concentrations of the PS (0.5 mM, IC50). These results suggest that the active targeted NC platform has an improved PDT effect on MCF-7 breast cancer cells.

Influencing factors and strategies of enhancing nanoparticles into tumors in vivo

The administration of nanoparticles (NPs) first faces the challenges of evading renal filtration and clearance of reticuloendothelial system (RES). After that, NPs infiltrate through the expanded endothelial space and penetrated the dense stroma of tumor microenvironment to tumor cells. As long as possible to prolong the time of NPs remaining in tumor tissue, NPs release active agent and induce pharmacological action. This review provides a comprehensive summary of the physical and chemical properties of NPs and the influence of various biological factors in tumor microenvironment, and discusses how to improve the final efficacy through adjusting the characteristics and structure of NPs. Perspectives and future directions are also provided.

When drug nanocarriers miss their target: extracellular diffusion and cell uptake are not enough to be effective

Biocompatible nanoscale iron carboxylate metal-organic frameworks (nanoMOFs) have already demonstrated their ability to efficiently deliver various therapeutic molecules. The versatility of the synthesis methods and functionalization strategies could further improve their drug carrier potential. However, in oncology, preclinical evaluation still suffers from the lack of relevant models able to mimic the heterogeneity and the microenvironment of human tumors. This may impact the significance of the preclinical data, hindering the clinical translation and drug development process. Motivated by this hurdle, a 3D lung tumor model is herein developed to investigate nanoMOFs, as bare nanoparticles or coated with polyethylene glycol. Loading with doxorubicin, as a model drug, enables the investigation of their penetration capacity and efficacy in the 3D tumor nodule. NanoMOFs carry a large cargo, can diffuse efficiently within the tumor and are capable of significant intracellular penetration. Nevertheless, they prove to be therapeutically ineffective because the loaded drug is sequestrated in the lysosomal compartment and does not reach the nucleus, the doxorubicin sub-cellular target. These results question the in vivo evaluation of these nanoMOFs and call for further optimization to achieve successful drug delivery.

Glutathione-responsive PLGA nanocomplex for dual delivery of doxorubicin and curcumin to overcome tumor multidrug resistance

Aim: This work aims to develop an injectable nano-drug delivery system to overcome tumor multidrug resistance (MDR). Methods: A drug delivery nanoplatform based on PEGylated PLGA with glutathione (GSH) responsivity was constructed for dual delivery of doxorubicin and curcumin (termed DCNP), and its MDR reversal efficiency was studied in vitro and in vivo. Results: The DCNPs exhibited a rapid drug release profile under high GSH concentration and could enhance the cellular uptake and cytotoxicity of doxorubicin to MDR cancer cells. Moreover, the DCNPs showed better biocompatibility, longer blood circulation and enhanced antitumor efficiency compared with free drugs. Conclusion: The GSH-responsive nanocarrier is believed to be a promising candidate for overcoming tumor MDR.

All-trans retinoic acid in anticancer therapy: how nanotechnology can enhance its efficacy and resolve its drawbacks

Introduction: All-trans retinoic acid (ATRA, tretinoin) is the main drug used in the treatment of acute promyelocytic leukemia (APL). Despite its impressive activity against APL, the same could not be clinically observed in other types of cancer. Nanotechnology can be a tool to enhance ATRA anticancer efficacy and resolve its drawbacks in APL as well as in other malignancies.Areas covered: This review covers ATRA use in APL and non-APL cancers, the problems that were found in ATRA therapy and how nanoencapsulation can aid to circumvent them. Pre-clinical results obtained with nanoencapsulated ATRA are shown as well as the two ATRA products based on nanotechnology that were clinically tested: ATRA-IV® and Apealea®.Expert opinion: ATRA presents interesting properties to be used in anticancer therapy with a notorious differentiation and antimetastatic activity. Bioavailability and resistance limitations impair the use of ATRA in non-APL cancers. Nanotechnology can circumvent these issues and provide tools to enhance its anticancer activities, such as co-loading of multiple drug and active targeting to tumor site.

Synthetic Receptor-Based Targeting Strategies to Improve Tumor Drug Delivery

Heterogeneity in tumor expression as well as expression in normal tissues of various targets limit the usefulness of current ligand-based active targeting approaches. Incorporation of synthetic receptors, which can be recognized by delivery systems engineered to present specific functional groups on the surface, is a novel approach to improve tumor targeting. Alternatively, introduction of synthetic functionalities on cellular carriers can also enhance tumor targeting. We review various strategies that have been utilized for the introduction of synthetic targets in tumor tissues. The introduction of synthetic functional groups in the tumor through improved strategies is anticipated to result in improved target specificity and reduced heterogeneity in target expression.

Update on drug transporter proteins in acute myeloid leukemia: Pathological implication and clinical setting

Acute myeloid leukemia (AML) is one of the most common hematological neoplasia causing death worldwide. The long-term overall survival is unsatisfactory due to many factors including older age, genetic heterogeneity and molecular characteristics comprising additional mutations, and resistance to chemotherapeutic drugs. The expression of ABCB1/P-glycoprotein, ABCC1/MRP1, ABCG2/BCRP and LRP transporter proteins is considered the major reason for multidrug resistance (MDR) in AML, however conflicting data have been reported. Here, we review the main issues about drug transporter proteins in AML clinical scenario, and highlight the clinicopathological significance of MDR phenotype associated with ABCB1 polymorphisms and FLT3 mutation.

Functional Doxorubicin-Loaded Omega-3 Unsaturated Fatty Acids Nanoparticles in Reversing Hepatocellular Carcinoma Multidrug Resistance

Background

This study investigated a nanoparticle drug delivery system to reverse multidrug resistance (MDR) and assessed its anticancer efficacy in hepatocellular carcinoma (HCC).

Material/Methods

Docosahexaenoic acid (DHA) was used as the functional excipient and doxorubicin (DOX) as the chemotherapeutic drug to synthesize DOX nanoparticles (DOX-nano). The human HCC cell line HepG2 was used for experiments. HepG2/DOX, HepG2+DOX, HepG2+DOX-nano, HepG2/DOX+DOX, and HepG2/DOX+DOX-nano groups cells were treated with DOX or DOX-nano (5 μg/mL). Nude mice bearing a HepG2/DOX xenograft were divided into model, DOX, vector-nano, and DOX-nano groups and injected with saline, DOX reagent, vector-nano, and DOX-nano (2 mg/kg), respectively. Next, cytotoxicity, cellular uptake, cell apoptosis and migration, fluorescence imaging, TUNEL assay, and tumor inhibition effects were assessed in vitro and in vivo. Furthermore, expression of MDR-related proteins was also detected using western blotting.

Results

Fluorescence imaging showed that the DOX uptake in the DOX-nano-treated group was the strongest in the HCC cells or tumors. Cell apoptosis was significantly increased in DOX-nano-treated HepG2/DOX cells and tumors, and cell migration was significantly inhibited in the DOX-nano-treated HepG2/DOX cells compared with the other groups. The tumor inhibitory rate in DOX-nano-injected tumors was also significantly higher than in other groups. The expression of breast cancer resistance protein, B-cell lymphoma 2, lung resistance protein, multidrug resistance protein, and protein kinase C alpha was significantly decreased in DOX-nano-treated HepG2/DOX cells and xenograft tumors. Significantly better antitumor and MDR-reversing effects were also observed in the HepG2+DOX group compared with the HepG2/DOX group.

Conclusions

This study revealed the potential efficacy of a DOX-nano drug delivery system for the treatment of HCC, using HepG2/DOX cells and nude mice bearing HepG2/DOX xenografts.

NIR-II light triggered nitric oxide release nanoplatform combined chemo-photothermal therapy for overcoming multidrug resistant cancer

The overexpression of P-glycoprotein (P-gp) in multidrug resistance (MDR) cancer cells increases the efflux of anticancer drugs thereby causing the failure of clinical chemotherapy. To address this obstacle, in this study, we rationally designed a near-infrared (NIR) light-responsive nitric oxide (NO) delivery nanoplatform for targeting the MDR tumors based on core-shell structured nanocomposites. The mesoporous silica shell provided abundant sites for modification of the NO donor, N-diazeniumdiolate, and tumor-targeting molecule, folic acid (FA), and enabled high encapsulation capacity for doxorubicin (DOX) loading. Under NIR light irradiation, the generation of NO gas can efficiently augment chemotherapeutic effects via the inhibition of P-gp expression. Simultaneously, the photothermal conversion agents of the Cu_2-xSe core produce a large amount of heat for photothermal therapy (PTT). Finally, this combinational gas/chemo/PTT not only displays a superior and synergistic effect for overcoming MDR cancer, but also provides an efficient strategy to construct a multifunctional nano-drug delivery system with diversified therapeutic modalities.

Recent advances in drug delivery systems for targeting cancer stem cells

Cancer stem cells (CSCs) are a subpopulation of cancer cells with functions similar to those of normal stem cells. Although few in number, they are capable of self-renewal, unlimited proliferation, and multi-directional differentiation potential. In addition, CSCs have the ability to escape immune surveillance. Thus, they play an important role in the occurrence and development of tumors, and they are closely related to tumor invasion, metastasis, drug resistance, and recurrence after treatment. Therefore, specific targeting of CSCs may improve the efficiency of cancer therapy. A series of corresponding promising therapeutic strategies based on CSC targeting, such as the targeting of CSC niche, CSC signaling pathways, and CSC mitochondria, are currently under development. Given the rapid progression in this field and nanotechnology, drug delivery systems (DDSs) for CSC targeting are increasingly being developed. In this review, we summarize the advances in CSC-targeted DDSs. Furthermore, we highlight the latest developmental trends through the main line of CSC occurrence and development process; some considerations about the rationale, advantages, and limitations of different DDSs for CSC-targeted therapies were discussed.

The challenges and applications of nanotechnology against bacterial resistance

Bacterial resistance to the antibiotics develops rapidly and is increasingly serious health concern in the world. It is an insoluble topic due to the multiple resistant mechanisms. The overexpression of relative activities of the efflux pump has proven to be a frequent and important source of bacterial resistance. Efflux transporters in the membrane from the resistant bacteria could play a key role to inhibit the intracellular drug intake and impede the drug activities. However, nanoparticles (NPs), one of the most frequently used encapsulation materials, could increase the intracellular accumulation of the drug and inhibit the transporter activity effectively. The rational and successful application of nanotechnology is a key factor in overcoming bacterial resistance. Furthermore, nanoparticles such as metallic, carbon nanotubes and so on, may prevent the development of drug resistance and be associated with antibiotic agents, inhibiting biofilm formation or increasing the access into the target cell and exterminating the bacteria eventually. In the current study, the mechanisms of bacterial resistance are discussed and summarized. Additionally, the opportunities and challenges in the use of nanoparticles against bacterial resistance are also illuminated. At the same time, the use of nanoparticles to combat multidrug-resistant bacteria is also investigated by coupling natural antimicrobials or other alternatives. In short, we have provided a new perspective for the application of nanoparticles against multidrug-resistant bacteria.

Indoxacarb-loaded fluorescent mesoporous silica nanoparticles for effective control of Plutella xylostella L. with decreased detoxification enzymes activities

BACKGROUND

Plutella xylostella L. is a cosmopolitan lepidopteron insect pest for numerous vegetables and crops. The extensive use of insecticides has resulted in the emergence of resistance in P. xylostella. Thus, development of innovative strategies to overcome the insecticide resistance and control P. xylostella effectively is highly desirable. Inspired by the concept and breakthrough of nanomedical strategies to treat multidrug resistance, nanotechnology may find potential application in overcoming or delaying insecticide resistance.

RESULTS

Carbon dots-embedded fluorescent mesoporous silica nanoparticles (FL-SiO₂ NPs) were successfully developed. Indoxacarb-loaded nanoparticles (IN@FL-SiO₂ NPs) were facilely prepared with loading content of 24%. The release of indoxacarb from IN@FL-SiO₂ NPs was pH sensitive. IN@FL-SiO₂ NPs exhibited better insecticidal activity against P. xylostella than indoxacarb technical under the same doses of active ingredient applied. Moreover, the activities of detoxification enzymes including GST, CarE, and P450 of P. xylostella were suppressed by treatment with IN@FL-SiO₂ NPs. Furthermore, the entry of FL-SiO₂ NPs into the midgut of P. xylostella was confirmed by CLSM observation.

CONCLUSIONS

Although there is no absolute correlation between the enzyme activity and resistance, the change in corresponding enzyme activity can afford valuable information on the resistance situation. IN@FL-SiO₂ NPs treated P. xylostella displayed higher mortality, along with decreased enzymes activities, which indicates that nano-based delivery system of insecticide could be potentially applied in insecticide resistance management. © 2020 Society of Chemical Industry.

A Functionalized Polydopamine Theranostic Nanoprobe for Efficient Imaging of miRNA-21 and In Vivo Synergetic Cancer Therapy

MicroRNAs (miRNAs) are emerging as vital biomarkers since their abnormal expression is associated with various disease types including cancer. Therefore, it is essential to develop a sensitive and specific platform to monitor the dynamic expression of miRNAs for early clinical diagnosis and treatment. In this study, we designed a functionalized polydopamine (PDA)-based theranostic nanoprobe for efficient detection of miRNA-21 and in vivo synergistic cancer therapy. PDA was modified with polyethylene glycol (PEG) and the obtained PDA-PEG nanoparticles showed good stability in different solutions. PDA-PEG nanoparticles were loaded with fluorescein isothiocyanate (FITC)-labeled hairpin DNA (hpDNA) and an anticancer drug doxorubicin (DOX). In the absence of miRNA-21, PDA effectively quenched the fluorescence of FITC-labeled hpDNA. The presence of miRNA-21 specifically recognized hpDNA and induced the dissociation of hpDNA from PDA-PEG and subsequently recovered the fluorescence signals. Upon cellular uptake of these nanoprobes, a dose-dependent fluorescence activation and synergetic cytotoxic effect were observed due to the release of DOX and inhibition of miRNA-21 function. Furthermore, PDA-PEG-DOX-hpDNA nanoparticles can afford long-term monitoring of miRNA-21 and combined therapeutic efficacy in the nude mice bearing 4T1 tumors. Our results demonstrate the capability of PDA-PEG-DOX-hpDNA as a theranostic nanoprobe for continuously tracking of miRNAs and synergetic cancer therapy.