Applications of nanoparticle drug delivery systems for the reversal of multidrug resistance in cancer

Heparin-functionalized Cu-based metal-organic framework: An efficient active and passive targeting nanocarrier for anticancer doxorubicin drug delivery

In this study, by innovative combining the unique characteristics of Cu-based metal-organic framework (MOF) with the versatile attributes of saccharides (i.e., heparin, Hep), a promising approach is established for active and passive targeting DDS, Cu-MOF/Hep, with a pH-controlled release profile and enhanced drug efficacy. The characterization of the synthesized materials (i.e., FT-IR, XRD, SEM, EDX, TEM, DLS, and TGA) confirms the successful synthesis of Cu-MOF/Hep. In vitro studies concerning the loading and release of DOX observed that a higher amount of DOX was released at pH 5 (>90 % on 96 h, 41 °C) compared to pH 7.4 (<10 % on 96 h, 37 °C). The sensitive feature of the used MOF to the pH conditions increased the drug release in environmental conditions similar to cancer tissues. Furthermore, cytotoxicity assessments indicated notable cytotoxicity effects of DOX-loaded Cu-MOF/Hep on MCF-7 cells (IC50: ∼10 μg/mL in 48 h) with a significant apoptosis rate. The existence of CD44 receptors on the surfaces of cells underscores the significance of Hep-modified systems in facilitating the apoptosis of cancerous cells. The results suggest that the combined Cu-MOF and Hep have the potential to be a viable option for creating platforms that deliver anticancer treatments.

Ultrasound-assisted encapsulating folic acid-based carbon quantum dots within breast cancer cell-derived exosomes as a co-receptors-mediated anticancer nanocarrier for enhanced breast cancer therapy

The nonspecific nature of cancer drug delivery often results in substantial toxic side effects during treatments for breast cancer. To mitigate these negative outcomes, our approach involves loading methotrexate (MTX) within carbon quantum dots (CQDs) synthesized from folic acid, which are then enveloped in exosomal membranes obtained from breast cancer cells (Ex@MTX-CQDs). Analysis utilizing nanoparticle tracking techniques has demonstrated that these Ex@MTX-CQDs maintain the physical and biochemical properties of their exosomal precursors. The release profile of MTX indicated a restricted release percentage (less than 10%) under normal physiological conditions, which is contrasted by a more consistent release rate (approximately 65%) when emulating the conditions found within tumor tissues. The toxicological assessments have confirmed that the presence of exosomes combined with leftover folic acid significantly improves the delivery efficacy of MTX directly to the cancerous cells through the binding to folate and heparan sulfate proteoglycan receptors. This process results in increased disruption of the mitochondrial membrane potential and subsequently triggers apoptosis, ultimately leading to the destruction of cancerous cells. Our research could potentially contribute to the further innovation and application of nanocarriers derived from biological sources for the targeted treatment of breast cancer.

Degradable bifunctional phototherapy composites based on upconversion nanoparticle-metal phenolic network for multimodal tumor therapy in the near-infrared biowindow

Phototherapy has garnered increasing attention as it allows for precise treatment of tumor sites with its accurate spatiotemporal control. In this study, we have successfully synthesized degradable bifunctional phototherapy agents (UCNPs@mSiO2@MPN-MC540/DOX) based on upconversion nanoparticle (UCNPs) and metal phenolic network (MPN), serving as a novel nanoplatform for multimodal tumor treatment in the near-infrared (NIR) biological window. To address the issue of low light penetration depth, the UCNPs we synthesized exhibited efficient light conversion ability under 808 nm laser irradiation to activate the photosensitizer Merocyanine 540 (MC540) for photodynamic therapy. Simultaneously, the 808 nm NIR light can also excite the MPN layer to achieve photothermal therapy for tumors. Additionally, the MPN layer possesses the capability of self-degradation under weakly acidic conditions. Within the tumor microenvironment, the MPN layer gradually degrades, facilitating the controlled release of the chemotherapy drug doxorubicin (DOX), thus achieving pH-responsive drug release and reducing the side effects of chemotherapy. This study provides an example of NIR-excited multimodal tumor treatment and pH-responsive drug release, offering a therapy model for precise tumor therapy.

Nanodelivery systems: An efficient and target-specific approach for drug-resistant cancers

BACKGROUND

Cancer treatment is still a global health challenge. Nowadays, chemotherapy is widely applied for treating cancer and reducing its burden. However, its application might be in accordance with various adverse effects by exposing the healthy tissues and multidrug resistance (MDR), leading to disease relapse or metastasis. In addition, due to tumor heterogeneity and the varied pharmacokinetic features of prescribed drugs, combination therapy has only shown modestly improved results in MDR malignancies. Nanotechnology has been explored as a potential tool for cancer treatment, due to the efficiency of nanoparticles to function as a vehicle for drug delivery.

METHODS

With this viewpoint, functionalized nanosystems have been investigated as a potential strategy to overcome drug resistance.

RESULTS

This approach aims to improve the efficacy of anticancer medicines while decreasing their associated side effects through a range of mechanisms, such as bypassing drug efflux, controlling drug release, and disrupting metabolism. This review discusses the MDR mechanisms contributing to therapeutic failure, the most cutting-edge approaches used in nanomedicine to create and assess nanocarriers, and designed nanomedicine to counteract MDR with emphasis on recent developments, their potential, and limitations.

CONCLUSIONS

Studies have shown that nanoparticle-mediated drug delivery confers distinct benefits over traditional pharmaceuticals, including improved biocompatibility, stability, permeability, retention effect, and targeting capabilities.

cRGD-Conjugated GdIO Nanoclusters for the Theranostics of Pancreatic Cancer through the Combination of T1-T2 Dual-Modal MRI and DTX Delivery

Clinically, magnetic resonance imaging (MRI) often uses contrast agents (CAs) to improve image contrast, but single-signal MRI CAs are often susceptible to calcification, hemorrhage, and magnetic sensitivity. Herein, iron acetylacetone and gadolinium acetylacetone were used as raw materials to synthesize a T1-T2 dual-mode imaging gadolinium-doped iron oxide (GdIO) nanocluster. Moreover, to endow the nanoclusters with targeting properties and achieve antitumor effects, the cyclic Arg-Gly-Asp (cRGD) peptide and docetaxel (DTX) were attached to the nanocluster surface, and the efficacy of the decorated nanoclusters against pancreatic cancer was evaluated. The final synthesized material cRGD-GdIO-DTX actively targeted αvβ3 on the surface of Panc-1 pancreatic cancer cells. Compared with conventional passive targeting, the enrichment of cRGD-GdIO-DTX in tumor tissues improved, and the diagnostic accuracy was significantly enhanced. Moreover, the acidic tumor microenvironment triggered the release of DTX from cRGD-GdIO-DTX, thus achieving tumor treatment. The inhibition of the proliferation of SW1990 and Panc-1 pancreatic cancer cells by cRGD-GdIO-DTX was much stronger than that by the untargeted GdIO-DTX and free DTX in vitro. In addition, in a human pancreatic cancer xenograft model, cRGD-GdIO-DTX considerably slowed tumor development and demonstrated excellent magnetic resonance enhancement. Our results suggest that cRGD-GdIO-DTX has potential applications for the precise diagnosis and efficient treatment of pancreatic cancer.

Insights on the Role of Polyphenols in Combating Cancer Drug Resistance

Chemotherapy resistance is still a serious problem in the treatment of most cancers. Many cellular and molecular mechanisms contribute to both inherent and acquired drug resistance. They include the use of unaffected growth-signaling pathways, changes in the tumor microenvironment, and the active transport of medicines out of the cell. The antioxidant capacity of polyphenols and their potential to inhibit the activation of procarcinogens, cancer cell proliferation, metastasis, and angiogenesis, as well as to promote the inhibition or downregulation of active drug efflux transporters, have been linked to a reduced risk of cancer in epidemiological studies. Polyphenols also have the ability to alter immunological responses and inflammatory cascades, as well as trigger apoptosis in cancer cells. The discovery of the relationship between abnormal growth signaling and metabolic dysfunction in cancer cells highlights the importance of further investigating the effects of dietary polyphenols, including their ability to boost the efficacy of chemotherapy and avoid multidrug resistance (MDR). Here, it is summarized what is known regarding the effectiveness of natural polyphenolic compounds in counteracting the resistance that might develop to cancer drugs as a result of a variety of different mechanisms.

Recent Advances in the Application of ATRP in the Synthesis of Drug Delivery Systems

Advances in atom transfer radical polymerization (ATRP) have enabled the precise design and preparation of nanostructured polymeric materials for a variety of biomedical applications. This paper briefly summarizes recent developments in the synthesis of bio-therapeutics for drug delivery based on linear and branched block copolymers and bioconjugates using ATRP, which have been tested in drug delivery systems (DDSs) over the past decade. An important trend is the rapid development of a number of smart DDSs that can release bioactive materials in response to certain external stimuli, either physical (e.g., light, ultrasound, or temperature) or chemical factors (e.g., changes in pH values and/or environmental redox potential). The use of ATRPs in the synthesis of polymeric bioconjugates containing drugs, proteins, and nucleic acids, as well as systems applied in combination therapies, has also received considerable attention.

Nano Strategies for Artemisinin Derivatives to Enhance Reverse Efficiency of Multidrug Resistance in Breast Cancer

Artemisinin (ART) has been found to exert anti-tumor activity by regulating the cell cycle, inducing apoptosis, inhibiting angiogenesis and tumor invasion and metastasis. Its derivatives (ARTs) can regulate the expression of drug-resistant proteins and reverse the multidrug resistance (MDR) of tumor cells by inhibiting intracellular drug efflux, inducing apoptosis and autophagy of tumor cells, thus enhancing the sensitivity of tumor cells to chemotherapy and radiotherapy. Recent studies have shown that nanodrugs play an important role in the diagnosis and treatment of cancer, which can effectively solve the shortcomings of poor hydrophilicity and low bioavailability of ARTs in the human body, prolong the in vivo circulation time, improve the targeting of drugs (including tumor tissues or specific organelles), and control the release of drugs in target tissues, thereby reducing the side effect. This review systematically summarized the latest research progress of nano-strategies of ARTs to enhance the efficiency of MDR reversal in breast cancer (BC) from the following two aspects: (1) Chemicals encapsulated in nanomaterials based on innovative anti-proliferation mechanism: non-ABC transporter receptor candidate related to ferroptosis (dihydroartemisinin/DHA analogs). (2) Combination therapy strategy of nanomedicine (drug-drug combination therapy, drug-gene combination, and chemical-physical therapy). Self-assembled nano-delivery systems enhance therapeutic efficacy through increased drug loading, rapid reactive release, optimized delivery sequence, and realization of cascade-increasing effects. New nanotechnology methods must be designed for specific delivery routines to achieve targeting administration and overcome MDR without affecting normal cells. The significance of this review is to expect that ART and ARTs can be widely used in clinical practice. In the future, nanotechnology can help people to treat multidrug resistance of breast cancer more accurately and efficiently.

Self-assembled amphiphilic copolymers-doxorubicin conjugated nanoparticles for gastric cancer therapy with low in vivo toxicity and high efficacy

Amphiphilic copolymers have long been utilized to turn hydrophobic anticancer drugs into nanoparticles administered to patients with cancer. A lack of stability in these monotherapies may be blamed for their poor clinical results in patients with cancer. We propose novel nanotherapies based on polymeric small prodrugs that preserve pharmacologic effectiveness while significantly reducing the toxicity of the fabricated drugs in animals to overcome this problem. Doxorubicin is attached to the end of the PLA fragments through a hydrolyzable ester bond utilizing methoxypolyethylene glycol-block-poly(d, l-lactic acid) (mPEG-PCL(2K)) with conjugates to mimic the self-assembly of colloidal nanotherapies. In a gastric cancer xenograft model, this nanotherapy displays a long-lasting suppression of tumor growth once a reasonable dosage is administered. Our findings imply that a toxic chemical and hydrophobic can be converted into therapeutic effective self-delivery nanotreatment.

Antitumor Effects of a Solid Lipid Nanoparticle Loaded with Gemcitabine and Oxaliplatin on the Viability, Apoptosis, Autophagy and Hsp90 of Ovarian Cancer Cells

Aim: The present study aimed to explore the sensitizing capability of the anticancer agents, gemcitabine (GEM) and oxaliplatin (OXA), encapsulated in a novel SLN (GEM:OXA-SLN) against the ovarian cancer cell lines.

METHODS

A novel SLN, prepared using hot homogenization by mixing phosphatidylcholine, cholesterol, tween 80 and oleic acid, was characterized using Transmission Electron Microscope and zetasizer. The anticancer activities and the underlying molecular mechanisms of GEM:OXA-SLN were investigated.

RESULTS

The average z-diameter of the homogeneous spherical GEM:OXA-SLN was (70.33 ± 0.70) nm with zeta potential (-7.69 ± 0.61) mV. GEM:OXA-SLN significantly inhibited the viability of ovarian cancer cells in a dose-dependent manner within 24 h. It also triggered the induction of autophagy cellular death, suppression of multidrug resistance efflux pump and inhibition of heat shock protein (Hsp90).

CONCLUSION

The encapsulation of GEM and OXA in SLN improved the efficacy of the drugs and diminished the ovarian cancer cell's resistance.

Drug delivery systems for cancer treatment: a review of marine-derived polysaccharides

Abstract:

Cancer is a disease characterized by uncontrolled cell proliferation and the spread of cells to other tissues and remains one of the worldwide problems waiting to be solved. There are various treatment strategies for cancer, such as chemotherapy, surgery, radiotherapy, and immunotherapy, although it varies according to its type and stage. Many chemotherapeutic agents have limited clinical use due to lack of efficacy, off-target toxicity, metabolic instability, or poor pharmacokinetics. One possible solution to this high rate of clinical failure is to design drug delivery systems that deliver drugs in a controlled and specific manner and are not toxic to normal cells. Marine systems contain biodiversity, including components and materials that can be used in biomedical applications and therapy. Biomaterials such as chitin, chitosan, alginate, carrageenan, fucoidan, hyaluronan, agarose, and ulvan obtained from marine organisms have found use in DDSs today. These polysaccharides are biocompatible, non-toxic, biodegradable, and cost-effective, making them ideal raw materials for increasingly complex DDSs with a potentially regulated release. In this review, the contributions of polysaccharides from the marine environment to the development of anticancer drugs in DDSs will be discussed.

Lenvatinib and Cu2-xS nanocrystals co-encapsulated in poly(D,L-lactide-co-glycolide) for synergistic chemo-photothermal therapy against advanced hepatocellular carcinoma

Lenvatinib (LT) is gradually replacing sorafenib as an alternative targeted drug against advanced hepatocellular carcinoma (HCC). However, the anticancer effects of LT are still limited because of its low cytotoxicity, multidrug resistance (MDR), and tumor relapse. Herein, we constructed a smart biophotonic nanoplatform to overcome the barriers preventing high performance. LT and copper sulfide nanocrystals (Cu_2-xS NCs) with excellent photothermal properties in the near-infrared-II (NIR-II) zone were co-encapsulated in poly(D,L-lactide-co-glycolide) (PLGA) through nanoprecipitation. Both in vitro and in vivo evaluations demonstrated that Cu_2-xS NCs enhanced the anticancer efficacy of LT, without recurrence. In addition, the presence of copper ions could allow glutathione (GHS) to be consumed and oxygen to be produced, likely suppressing the expression of P-glycoprotein (P-gp) and overcoming the issue of MDR relating to LT. More importantly, synergistic chemo-photothermal therapy with LT and Cu_2-xS NCs was more effective than any single therapy or theoretical combination. This nanoplatform is promising for advancing future LT-based treatment strategies for HCC therapy.

Mechanisms of Drug Resistance and Use of Nanoparticle Delivery to Overcome Resistance in Breast Cancers

Breast cancer is the leading cancer type diagnosed among women in the world. Unfortunately, drug resistance to current breast cancer chemotherapeutics remains the main challenge for a higher survival rate. The recent progress in the nanoparticle platforms and distinct features of nanoparticles that enhance the efficacy of therapeutic agents, such as improved delivery efficacy, increased intracellular cytotoxicity, and reduced side effects, hold great promise to overcome the observed drug resistance. Currently, multifaceted investigations are probing the resistance mechanisms associated with clinical drugs, and identifying new breast cancer-associated molecular targets that may lead to improved therapeutic approaches with the nanoparticle platforms. Nanoparticle platforms including siRNA, antibody-specific targeting and the role of nanoparticles in cellular processes and their effect on breast cancer were discussed in this article.

Drug Resistance in Metastatic Breast Cancer: Tumor Targeted Nanomedicine to the Rescue

Breast cancer, specifically metastatic breast, is a leading cause of morbidity and mortality in women. This is mainly due to relapse and reoccurrence of tumor. The primary reason for cancer relapse is the development of multidrug resistance (MDR) hampering the treatment and prognosis. MDR can occur due to a multitude of molecular events, including increased expression of efflux transporters such as P-gp, BCRP, or MRP1; epithelial to mesenchymal transition; and resistance development in breast cancer stem cells. Excessive dose dumping in chemotherapy can cause intrinsic anti-cancer MDR to appear prior to chemotherapy and after the treatment. Hence, novel targeted nanomedicines encapsulating chemotherapeutics and gene therapy products may assist to overcome cancer drug resistance. Targeted nanomedicines offer innovative strategies to overcome the limitations of conventional chemotherapy while permitting enhanced selectivity to cancer cells. Targeted nanotheranostics permit targeted drug release, precise breast cancer diagnosis, and importantly, the ability to overcome MDR. The article discusses various nanomedicines designed to selectively target breast cancer, triple negative breast cancer, and breast cancer stem cells. In addition, the review discusses recent approaches, including combination nanoparticles (NPs), theranostic NPs, and stimuli sensitive or “smart” NPs. Recent innovations in microRNA NPs and personalized medicine NPs are also discussed. Future perspective research for complex targeted and multi-stage responsive nanomedicines for metastatic breast cancer is discussed.

Antitumor potential of cisplatin loaded into SBA-15 mesoporous silica nanoparticles against B16F1 melanoma cells: in vitro and in vivo studies

CP (cisplatin) and mesoporous silica SBA-15 (Santa Barbara amorphous 15) loaded with CP (→SBA-15|CP) were tested in vitro and in vivo against low metastatic mouse melanoma B16F1 cell line. SBA-15 only, as drug carrier, is found to be not active, while CP and SBA-15|CP revealed high cytotoxicity in lower μM range. The activity of SBA-15|CP was found similar to the activity of CP alone. Both CP and SBA-15|CP induced inhibition of cell proliferation (carboxyfluorescein succinimidyl ester - CFSE assay) along with G2/M arrest (4',6-diamidino-2-phenylindole - DAPI assay). Apoptosis (Annexin V/ propidium iodide - PI assay), through caspase activation (apostat assay) and nitric oxide (NO) production (diacetate(4-amino-5-methylamino-2',7'-difluorofluorescein-diacetat) - DAF FM assay), was identified as main mode of cell death. However, slight elevated autophagy (acridine orange - AO assay) was detected in treated B16F1 cells. CP and SBA-15|CP did not affect production of ROS (reactive oxygen species) in B16F1 cells. Both SBA-15|CP and CP induced in B16F1 G2 arrest and subsequent senescence. SBA-15|CP, but not CP, blocked the growth of melanoma in C57BL/6 mice. Moreover, hepato- and nephrotoxicity in SBA-15|CP treated animals were diminished in comparison to CP confirming multiply improved antitumor potential of immobilized CP. Outstandingly, SBA-15 boosted in vivo activity and diminished side effects of CP.

Expanding Opportunities in Treatment of Leukemia by Solid Lipid Nanoparticles

Background:

Leukemia is a severe type of blood cancer that involves an abnormal proliferation of blood-forming cells. Its conventional treatment faces many challenges, including resistance, lack of specificity and high unwanted toxicity of drugs. Nano drug delivery systems help in overcoming these challenges by delivering the drug to the target site actively or passively. Solid lipid nanoparticles are gaining popularity because they reduce unwanted toxicity, are biocompatible, increase bioavailability and are versatile in terms of incorporated agents (hydrophilic as well as lipophilic drugs, genes, enzymes, etc.).

Purpose:

The aim of this review is to discuss recent advancements in anti-leukemic therapy utilizing solid lipid nanoparticles (SLNs) as successful carriers in enhancing the efficiency of the treatment and bioavailability of the incorporated drug along with overcoming multidrug resistance.

Methods:

This review represents the existing literature on the applications of SLNs in anti-leukemic therapy. A qualitative literature review has been performed for this purpose. We performed keyword research in popular databases such as Google Scholar, Wiley, Elsevier, Scopus, Google patent and PubMed. Only articles published in English and from reputed journals from specific fields were considered. Benchmark studies having major importance from 2000 to 2020 were selected to follow the progress in the field across the globe.

Results:

This article improves the understanding of the role of SLNs in the treatment of leukemia. Traditional anti-leukemic therapy involves many challenges, including resistance, lack of specificity and high unwanted toxicity of drugs. SLNs are emerging as a better alternative to conventional delivery systems as they can reduce unwanted toxicity, are biocompatible, and can provide active as well as passive molecular targeting.

Conclusion:

SLNs provide several advantages in drug delivery for leukemia, including enhancement of efficiency and bioavailability and reduction of toxicity by virtue of their small size, lipid core, non-dependency on organic solvents and versatility in terms of incorporated drugs.

Nanotechnological approaches for counteracting multidrug resistance in cancer

Every year, cancer accounts for a vast portion of deaths worldwide. Established clinical protocols are based on chemotherapy, which, however, is not tumor-selective and produces a series of unbearable side effects in healthy tissues. As a consequence, multidrug resistance (MDR) can arise causing metastatic progression and disease relapse. Combination therapy has demonstrated limited responses in the treatment of MDR, mainly due to the different pharmacokinetic properties of administered drugs and to tumor heterogeneity, challenges that still need to be solved in a significant percentage of cancer patients. In this perspective, we briefly discuss the most relevant MDR mechanisms leading to therapy failure and we report the most advanced strategies adopted in the nanomedicine field for the design and evaluation of ad hoc nanocarriers. We present some emerging classes of nanocarriers developed to reverse MDR and discuss recent progress evidencing their limits and promises.

Overcoming Doxorubicin Resistance with Lipid-Polymer Hybrid Nanoparticles Photoreleasing Nitric Oxide

We report on tailored lipid-polymer hybrid nanoparticles (NPs) delivering nitric oxide (NO) under the control of visible light as a tool for overcoming doxorubicin (DOX) resistance. The NPs consist of a polymeric core and a coating. They are appropriately designed to entrap DOX in the poly(lactide-co-glycolide) core and a NO photodonor (NOPD) in the phospholipid shell to avoid their mutual interaction both in the ground and excited states. The characteristic red fluorescence of DOX, useful for its tracking in cells, is well preserved upon incorporation within the NPs, even in the copresence of NOPD. The NP scaffold enhances the NO photoreleasing efficiency of the entrapped NOPD when compared with that of the free compound, and the copresence of DOX does not significantly affect such enhanced photochemical performance. Besides, the delivery of DOX and NOPD from NPs is also not mutually influenced. Experiments carried out in M14 DOX-resistant melanoma cells demonstrate that NO release from the multicargo NPs can be finely regulated by excitation with visible light, at a concentration level below the cytotoxic doses but sufficient enough to inhibit the efflux transporters mostly responsible for DOX cellular extrusion. This results in increased cellular retention of DOX with consequent enhancement of its antitumor activity. This approach, in principle, is not dependent on the type of chemotherapeutic used and may pave the way for new treatment modalities based on the photoregulated release of NO to overcome the multidrug resistance phenomenon and improve cancer chemotherapies.

Poly(ethylene glycol)-sheddable reduction-sensitive polyurethane micelles for triggered intracellular drug delivery for osteosarcoma treatment

BACKGROUND

The survival rate of osteosarcoma therapy still lags behind overall cancer therapies due to the intrinsic or acquired drug resistance. Developing novel drug delivery systems that may overcome drug resistance would greatly facilitate osteosarcoma therapy.

METHODS

Poly(ethylene glycol) (PEG)-sheddable reduction-sensitive polyurethane (SS-PU-SS-PEG) was synthesized using a disulfide-containing polycaprolactone diol as the hydrophobic block and a cystamine-functionalized PEG as the hydrophilic block. SS-PU-SS-PEG micelles were then prepared to load the anti-tumor drug Doxorubicin (DOX) in order to achieve triggered intracellular drug delivery to improve the efficacy of osteosarcoma therapy.

RESULTS

When DOX was used as a model drug, the drug-loaded SS-PU-SS-PEG micelles were about 82∼94 nm in diameter and exhibited good stability in phosphate buffer saline (PBS). The micelles could release about 80% DOX in a quantitative fashion within 5 hours under a reductive environment. The intracellular drug release of DOX-loaded SS-PU-SS-PEG micelles increased upon incubation with Saos-2 cells in vitro. The micelles had good biocompatibility. In vitro, DOX-loaded SS-PU-SS-PEG micelles showed significant antitumor activity toward Saos-2 cells, which was close to that of free DOX. In vivo, DOX-loaded SS-PU-SS-PEG micelles exhibited better antitumor activity than free DOX.

CONCLUSION

Findings from this study suggest that the SS-PU-SS-PEG micelles could achieve well-controlled triggered drug release in a reduction environment and could therefore improve the antitumor efficacy of osteosarcoma therapies.

TRANSLATION POTENTIAL OF THIS ARTICLE

In this study we developed PEG-sheddable reduction-sensitive polyurethane micelles (SS-PU-SS-PEG), which were able to achieve well-controlled triggered release of anti-tumor drug Doxorubicin (DOX) in an intracellular reduction environment. DOX-loaded SS-PU-SS-PEG micelles markedly improved the antitumor efficacy in a Saos-2 cells-bearing xenograft tumor model. Therefore, such micelles might be used as a novel drug delivery system for osteosarcoma treatment.

Nanoparticles carrying fingolimod and methotrexate enables targeted induction of apoptosis and immobilization of invasive thyroid cancer

Metastatic tumors are the main cause of cancer-related death, as the invading cancer cells disrupt normal functions of distant organs and are nearly impossible to eradicate by traditional cancer therapeutics. This is of special concern when the cancer has created multiple metastases and extensive surgery would be too dangerous to execute. Therefore, combination chemotherapy is often the selected treatment form. However, drug cocktails often have severe adverse effects on healthy cells, whereby the development of targeted drug delivery could minimize side-effects of drugs and increase the efficacy of the combination therapy. In this study, we utilized the folate antagonist methotrexate (MTX) as targeting ligand conjugated onto mesoporous silica nanoparticles (MSNs) for selective eradication of folate receptor-expressing invasive thyroid cancer cells. The MSNs was subsequently loaded with the drug fingolimod (FTY720), which has previously been shown to efficiently inhibit proliferation and invasion of aggressive thyroid cancer cells. To assess the efficiency of our carrier system, comprehensive in vitro methods were employed; including flow cytometry, confocal microscopy, viability assays, invasion assay, and label-free imaging techniques. The in vitro results show that MTX-conjugated and FTY720-loaded MSNs potently attenuated both the proliferation and invasion of the cancerous thyroid cells while keeping the off-target effects in normal thyroid cells reasonably low. For a more physiologically relevant in vivo approach we utilized the chick chorioallantoic membrane (CAM) assay, showing decreased invasive behavior of the thyroid derived xenografts and an increased necrotic phenotype compared to tumors that received the free drug cocktail. Thus, the developed multidrug-loaded MSNs effectively induced apoptosis and immobilization of invasive thyroid cancer cells, and could potentially be used as a carrier system for targeted drug delivery for the treatment of diverse forms of aggressive cancers that expresses folate receptors.

Enhanced Reactive Oxygen Species Generation by Mitochondria Targeting of Anticancer Drug To Overcome Tumor Multidrug Resistance

As a major clinical tumor chemotherapeutic burden, multidrug resistance (MDR) is often a result of up-regulation of P-glycoprotein (P-gp), which strongly enhances anticancer drug efflux. The excess mitochondrial reactive oxygen species (ROS) could not only inhibit the function of P-gp through insufficient adenosine triphosphate supply but also cause apoptosis in MDR cells. Here, we designed a mitochondria targeting nanoparticulate system (GNPs-P-Dox-GA) for overcoming MDR through enhanced ROS generation, where increased cellular uptake as well as mitochondria accumulation were both realized by glycyrrhetinic acid (GA). First, doxorubicin was conjugated with GA (GA-Dox) and then grafted onto a N-(2-hydroxypropyl) methacrylamide (HPMA) copolymer backbone via hydrazone bond (P-Dox-GA). The obtained P-Dox-GA was subsequently attached to the surface of gelatin nanoparticles (GNPs). As gelatin is a substrate of tumor extracellular metal matrix protease-2 (MMP2), GNPs-P-Dox-GA nanoparticles could be degraded and release small size P-Dox-GA to facilitate tumor tissue penetration. After P-Dox-GA internalized by tumor cells under GA mediation, Dox-GA detached from HPMA copolymer through hydrolysis of hydrazone bond and then efficiently delivered to mitochondria. Compared to non-GA modified carriers, GNPs-P-Dox-GA exhibited increased cellular uptake nearly 4-fold and mitochondria distribution 8.8-fold, and increased ROS production level nearly 3-fold, significantly decreased efflux rate (55% compared with Dox group) in drug resistant HepG2/ADR cells, and then led to improved in vitro antitumor efficiency in HepG2/ADR cells (IC₅₀ only 19.5% of unmodified ones) as well as exciting in vivo antitumor efficiency on HepG2/ADR heterotopic tumor nude mice (1.75-fold higher tumor growth inhibition rate than free drug).

pH-Responsive i-motif Conjugated Hyaluronic Acid/Polyethylenimine Complexes for Drug Delivery Systems

i-motif is cytosine (C)-rich oligonucleotide (ODN) which shows pH-responsive structure change in acidic condition. Therefore, it has been utilized for the trigger of intercalated drug release, responding to environmental pH change. In this study, 2.76 molecules of i-motif binding ODNs (IBOs) were conjugated to each hyaluronic acid (HA) via amide bond linkages. Synthesis of HA-IBO conjugate (HB) was confirmed by FT-IR and agarose gel electrophoresis with Stains-All staining. After hybridization of HB with i-motif ODN (IMO), it was confirmed that doxorubicin (DOX) could be loaded in HB-IMO hybrid structure (HBIM) with 65.6% of drug loading efficiency (DLE) and 25.0% of drug loading content (DLC). At pH 5.5, prompt and significant DOX release from HBIM was observed due to the disruption of HBIM hybrid structure via i-motif formation of IMO, contrary to pH 7.4 condition. Then, HBIM was complexed with low molecular weight polyethylenimine (PEI1.8k), forming positively charged nanostructures (Z-average size: 126.0 ± 0.4 nm, zeta-potential: 16.1 ± 0.3 mV). DOX-loaded HBIM/PEI complexes displayed higher anticancer efficacy than free DOX in A549 cells, showing the potential for pH-responsive anticancer drug delivery systems.

Protein corona variation in nanoparticles revisited: A dynamic grouping strategy

Bio-nano interface investigation models are mainly based on the type of proteins present on corona, bio-nano interaction responses and the evaluation of final outcomes. Due to the extensive diversity in correlative models for investigation of nanoparticles biological responses, a comprehensive model considering different aspects of bio-nano interface from nanoparticles properties to protein corona fingerprints appeared to be essential and cannot be ignored. In order to minimize divergence in studies in the era of bio-nano interface and protein corona with following therapeutic implications, a useful investigation model on the basis of RADAR concept is suggested. The contents of RADAR concept consist of five modules: 1- Reshape of our strategy for synthesis of nanoparticles (NPs), 2- Application of NPs selected based on human fluid, 3- Delivery strategy of NPs selected based on target tissue, 4- Analysis of proteins present on corona using correct procedures and 5- Risk assessment and risk reduction upon the collection and analysis of results to increase drug delivery efficiency and drug efficacy. RADAR grouping strategy for revisiting protein corona phenomenon as a key of success will be discussed with respect to the current state of knowledge.

Methotrexate loaded on magnetite iron nanoparticles coated with chitosan: Biosynthesis, characterization, and impact on human breast cancer MCF-7 cell line

Methotrexate (MTX) is effective therapeutic agent treated many tumors and autoimmune diseases. The aim of our study was to design an effective delivery nanocarrier for methotrexate to improve stability and biodistribution, reduce adverse effects and maximize clinical efficacy. Magnetite nanoparticles (Fe₃O₄-NPs) were synthesized using Pterocladiella. The size of Fe₃O₄-NPs, CS-Fe₃O₄-NPs and MTX/CS-Fe₃O₄-NPs were 37.6, 61.4 and 150 nm respectively. Methotrexate loading efficiency was 74.15% of total amount of MTX loaded on CS-Fe₃O₄-NPs and 39.8% of the loaded drug was initially released and the remaining amount was released through 120 h. The IC₅₀ of MTX and MTX/CS-Fe₃O₄-NPs was 51.4 and 9.7 μg/ml respectively after 72 h. MTX/CS-Fe₃O₄-NPs caused remarkable damage to the membrane of MCF-7 cells led to increasing the LDH activity 5 fold in MCF-7 cells as compared with MTX treated once. DNA fragmentation and caspase-3 activity were higher in MCF-7 cells treated with MTX/CS-Fe₃O₄-NPs than that of MTX. Up-regulation of caspase3 and DHFR genes expression was observed in the treatment with MTX/CS-Fe₃O₄-NPs. The loading of MTX on chitosan coated Fe₃O₄-NPs improves the release and anticancer efficacy of MTX for effective cancer treatment.

Functionalized 2D nanomaterials with switchable binding to investigate graphene-bacteria interactions

Graphene and its derivatives have recently attracted much attention for sensing and deactivating pathogens. However, the mechanism of multivalent interactions at the graphene-pathogen interface is not fully understood. Since different physicochemical parameters of graphene play a role at this interface, control over graphene's structure is necessary to study the mechanism of these interactions. In this work, different graphene derivatives and also zwitterionic graphene nanomaterials (ZGNMs) were synthesized with defined exposure, in terms of polymer coverage and functionality, and isoelectric points. Then, the switchable interactions of these nanomaterials with E. coli and Bacillus cereus were investigated to study the validity of the generally proposed "trapping" and "nano-knives" mechanisms for inactivating bacteria by graphene derivatives. It was found that the antibacterial activity of graphene derivatives strongly depends on the accessible area, i.e. edges and basal plane of sheets and tightness of their agglomerations. Our data clearly confirm the authenticity of "trapping" and "nano-knives" mechanisms for the antibacterial activity of graphene sheets.

Mitochondrial Targeted Doxorubicin-Triphenylphosphonium Delivered by Hyaluronic Acid Modified and pH Responsive Nanocarriers to Breast Tumor: in Vitro and in Vivo Studies

Multidrug resistance (MDR) is the major obstacle for chemotherapy. In a previous study, we have successfully synthesized a novel doxorubicin (DOX) derivative modified by triphenylphosphonium (TPP) to realize mitochondrial delivery of DOX and showed the potential of this compound to overcome DOX resistance in MDA-MB-435/DOX cells. (1) To introduce specificity for DOX-TPP to cancer cells, here we report on the conjugation of DOX-TPP to hyaluronic acid (HA) by hydrazone bond with adipic acid dihydrazide (ADH) as the acid-responsive linker, producing HA- hydra-DOX-TPP nanoparticles. Hyaluronic acid (HA) is a natural water-soluble linear glycosaminoglycan, which was hypothesized to increase the accumulation of nanoparticles containing DOX-TPP in the mitochondria of tumor cells upon systemic administration, overcoming DOX resistance, in vivo. Our results showed HA- hydra-DOX-TPP to self-assemble to core/shell nanoparticles of good dispersibility and effective release of DOX-TPP from the HA- hydra-DOX-TPP conjugate in cancer cells, which was followed by enhanced DOX mitochondria accumulation. The HA- hydra-DOX-TPP nanoparticles also showed improved anticancer effects, better tumor cell apoptosis, and better safety profile compared to free DOX in MCF-7/ADR bearing mice.

Cholecalciferol-PEG Conjugate Based Nanomicelles of Doxorubicin for Treatment of Triple-Negative Breast Cancer

Triple-negative breast cancer (TNBC) is the leading cancer in women. Chemotherapeutic agents used for TNBC are mainly associated with dose-dependent toxicities and development of resistance. Hence, novel strategies to overcome resistance and to offer dose reduction are warranted. In this study, we designed a novel dual-functioning agent, conjugate of cholecalciferol with PEG2000 (PEGCCF) which can self-assemble into micelles to encapsulate doxorubicin (DOX) and act as a chemosensitizer to improve the therapeutic potential of DOX. DOX-loaded PEGCCF (PEGCCF-DOX) micelles have particle size, polydispersity index (PDI), and zeta potential of 40 ± 8.7 nm, 0.180 ± 0.051, and 2.39 ± 0.157 mV, respectively. Cellular accumulation studies confirmed that PEGCCF was able to concentration-dependently enhance the cellular accumulation of DOX and rhodamine 123 in MDA-MB-231 cells through its P-glycoprotein (P-gp) inhibition activity. PEGCCF-DOX exhibited 1.8-, 1.5-, and 2.9-fold enhancement in cytotoxicity of DOX in MDA-MB-231, MDA-MB-468, and MDA-MB-231DR (DOX-resistant) cell lines, respectively. Western blot analyses showed that PEGCCF-DOX caused significant reduction in tumor markers including mTOR, c-Myc, and antiapoptotic marker Bcl-xl along with upregulation of preapoptotic marker Bax. Further, reduction in mTOR activity by PEGCCF-DOX indicates reduced P-gp activity due to P-gp downregulation as well and, hence, PEGCCF causes enhanced chemosensitization and induces apoptosis. Substantially enhanced apoptotic activity of DOX (10-fold) in MDA-MB-231(DR) cells confirmed apoptotic potential of PEGCCF. Conclusively, PEGCCF nanomicelles are promising delivery systems for improving anticancer activity of DOX in TNBC, thereby reducing its side effects and may act as a potential carrier for other chemotherapeutic agents.

Inhibit or Evade Multidrug Resistance P-Glycoprotein in Cancer Treatment

Multidrug resistance (MDR) is a major cause of failure in cancer chemotherapy. P-glycoprotein (P-gp), a promiscuous drug efflux pump, has been extensively studied for its association with MDR due to overexpression in cancer cells. Several P-gp inhibitors or modulators have been investigated in clinical trials in hope of circumventing MDR, with only limited success. Alternative strategies are actively pursued, such as the modification of existing drugs, development of new drugs, or combination of novel drug delivery agents to evade P-gp-dependent efflux. Despite the importance and numerous studies, these efforts have mostly been undertaken without a priori knowledge of how drugs interact with P-gp at the molecular level. This review highlights and discusses progress toward and challenges impeding drug development for inhibiting or evading P-gp in the context of our improved understanding of the structural basis and mechanism of P-gp-mediated MDR.

Polysaccharide-based nanoparticles for co-loading mitoxantrone and verapamil to overcome multidrug resistance in breast tumor

The aim of this study was to evaluate the potential of polyelectrolyte complex nanoparticles (PENPs) based on hyaluronic acid/chitosan hydrochloride (HA/HCS) for co-loading mitoxantrone (MTO) and verapamil (VRP) to overcome multidrug resistance in breast tumors. PENPs co-loaded with MTO and VRP (MTO-VRP-PENPs) were affected by the method of preparation, molecular weight of HA, mass ratios and initial concentrations of HA/HCS, pH, and drug quantities. Optimized MTO-VRP-PENPs were ~209 nm in size with a zeta potential of approximately -24 mV. Encapsulation efficiencies (%) of MTO and VRP were 98.33%±0.27% and 44.21%±8.62%, respectively. MTO and VRP were successfully encapsulated in PENPs in a molecular or amorphous state. MTO-VRP-PENPs showed significant cytotoxicity in MCF-7/ADR cells in contrast to MTO-loaded PENPs (MTO-PENPs). The reversal index of MTO-VRP-PENPs was 13.25 and 10.33 times greater than that of the free MTO and MTO-PENPs, respectively. In conclusion, MTO-VRP-PENPs may serve as a promising carrier to overcome tumor drug resistance.

Silicon-based nanotheranostics

With the rapid expansion of nanoscience and nanotechnology in interdisciplinary fields, multifunctional nanomaterials have attracted particular attention. Recent advances in nanotherapeutics for cancer applications provided diverse groups of synthetic particles with defined cellular and biological functions. The advance of nanotechnology significantly increased the number of possibilities for the construction of diverse biological tools. Such materials are destined to be of great importance because of the opportunity to combine the biotechnological potential of nanoparticles together with the recognition, sensitivity and modulation of cellular pathways or genes when applied to living organisms. In this mini review three main types of Si-based nanomaterials are highlighted in the area of their application for therapy and imaging: porous silicon nanoparticles (pSiNPs), mesoporous silica nanoparticles (MSNs), focusing on their nanoconstructs containing coordination compounds, and periodic mesoporous silica nanoparticles (PMONPs). Moreover, a critical discussion on the research efforts in the construction of nanotheranostics is presented.

Anti-tumor effects of the American cockroach, Periplaneta americana

Since the incidence of cancer has been on the rise due to increasing exposure to various carcinogenic factors in recent years, cancer has gradually become the first killer to the health of human beings. A growing attention has been paid to anti-cancer effects of traditional Chinese medicine (TCM) with low toxicity and good efficacy. As a kind of TCM, Periplaneta americana (P. americana) has a good effect on clinical application, and its anti-tumor effects has been increasingly well studied. In this review, the research progress on the anti-tumor effects of P. americana was summarized. The main mechanisms of its anti-tumor effects include suppression of tumor cell growth, induction of cell cycle arrest and tumor cell apoptosis, inhibition of angiogenesis, enhancement of immunity, and reversal of tumor drug resistance. This review aims to provide an overview of the research on anti-tumor effects of P. americana and aids in its further application as an anti-tumor drug.

New concepts of personalized therapy in salivary gland carcinomas

Salivary gland carcinomas are rare tumours and therapy strategies are less standardized than in lung, gastric or breast cancer. Therapy is based on surgery, but not all carcinomas are completely resectable, e.g. because carcinomas often show infiltration of nerves. For further therapy decision pathology is recommended, but evaluation of potential targets for personalized therapy is not part of the routine panel. Many salivary gland carcinomas can be resistant to radio- and/or chemotherapy, which limits therapeutic options. This review summarizes new concepts for personalized therapy in salivary gland carcinoma patients. Targeting growth receptors HER2, EGFR, AR and ER is possible but, in some studies, potential target molecules were not adequately tested before therapy. In addition, approximately 20-25% of carcinomas have RAS mutation (mainly H-RAS), which could explain resistance to therapy. Possible therapy options in the future could be immunomodulation (inhibition of PDL1/PD1 signalling), nanoparticles (gold nanoparticles conjugated to cetuximab can increase radiosensitivity) and drug delivery systems (trastuzumab emtansine/T-DM1).

Overcoming multidrug resistance through co-delivery of ROS-generating nano-machinery in cancer therapeutics

The use of nanotechnology to overcome multidrug resistance (MDR) in cancer cells has been predominant. Herein, we report the conjugation of copper(ii)-doxorubicin complexes on the surfaces of layered double hydroxide nanoparticles (LDHs) along with ascorbic acid intercalation in the gallery space to demonstrate synergistic effects to conquer MDR. The pH-sensitive release of doxorubicin (Dox) and the sustained release of ascorbic acid (AA) generate high amounts of hydrogen peroxide intracellularly that concomitantly results in conversion to cytotoxic free radicals through a copper(ii)-catalyzed Fenton-like reaction. Therefore, the combination of the chemotherapeutic agent (Dox) and free radical attack can devastate the MDR for effective cancer treatment through the co-delivery system.

SBA-15 mesoporous silica particles loaded with cisplatin induce senescence in B16F10 cells

Nanoparticles obtained by loading of cisplatin into mesoporous silica SBA-15 (SBA-15|CP) change the phenotype of surviving B16F10 melanoma cells from malignant to senescent.