Enhanced Chemotherapy of Cancer Using pH-Sensitive Mesoporous Silica Nanoparticles to Antagonize P-Glycoprotein–Mediated Drug Resistance

Systemic Codelivery of Thymoquinone and Doxorubicin by Targeted Mesoporous Silica Nanoparticle Sensitizes Doxorubicin-Resistant Breast Cancer by Interfering between the MDR1/P-gp and miR 298 Crosstalk

Multi drug resistance (MDR) in breast carcinoma still poses a significant impairment to successful chemotherapy. As the arsenal of anticancer agents increases with improved preclinical methods, the growth of therapeutic drug combinations is now unprecedented. The malignancies addressed by mono drugs often fail to limit cancer progression, resulting in resistant cancer, thereby offering combinatorial therapies a terrific edge over monodrug regimes. However, the selection of drug combinations required enough preliminary evidence for their synergistic effect. The fundamental mechanisms of MDR to chemotherapeutics are associated with the overexpression of membrane efflux pumps, alternations in drug targets, and increased drug metabolism. Unfortunately, it is very difficult for drugs to overcome resistance produced on their own or by another different drug action. In this context, herein, we report a simple delivery system for coencapsulation and intracellular codelivery of dual-drug thymoquinone (TQ) and doxorubicin (DOX) to resensitize DOX-resistant MDA MB231 cell line (231 R). The 231 R cell line developed in our lab showed an enhanced expression of the ATP-binding cassette (ABC) transporters P-gp1/MDR-1 and a declined miR-298 expression. The present delivery system is based on amine-functionalized mesoporous silica nanoparticles (MSNs), in which the side chain amine functional group was used to react with the carbonyl group of TQ, which acts as a pro-drug system (TQ-MSN) to release TQ and DOX simultaneously. DOX was encapsulated later into the above TQ-MSN by a simple diffusion method. The drugs containing MSNs were further coated with a hyaluronic acid-conjugated PEG-PLGA polymer (HA@TQ-DOX-MSN). This simple nanostrategy interferes with the MDR-1/miR-298 cross-talk, thereby allowing a significant reduction in drug efflux from the cell and highlighting a promising nanotechnology-based combinatorial delivery approach in managing breast cancer chemoresistance.

Strategies, Challenges, and Prospects of Nanoparticles in Gynecological Malignancies

Gynecologic cancers are a significant health issue for women globally. Early detection and successful treatment of these tumors are crucial for the survival of female patients. Conventional therapies are often ineffective and harsh, particularly in advanced stages, necessitating the exploration of new therapy options. Nanotechnology offers a novel approach to biomedicine. A novel biosensor utilizing bionanotechnology can be employed for early tumor identification and therapy due to the distinctive physical and chemical characteristics of nanoparticles. Nanoparticles have been rapidly applied in the field of gynecologic malignancies, leading to significant advancements in recent years. This study highlights the significance of nanoparticles in treating gynecological cancers. It focuses on using nanoparticles for precise diagnosis and continuous monitoring of the disease, innovative imaging, and analytic methods, as well as multifunctional drug delivery systems and targeted therapies. This review examines several nanocarrier systems, such as dendrimers, liposomes, nanocapsules, and nanomicelles, for gynecological malignancies. The review also examines the enhanced therapeutic potential and targeted delivery of ligand-functionalized nanoformulations for gynecological cancers compared to nonfunctionalized anoformulations. In conclusion, the text also discusses the constraints and future exploration prospects of nanoparticles in chemotherapeutics. Nanotechnology will offer precise methods for diagnosing and treating gynecological cancers.

Dual electro-/pH-responsive nanoparticle/hydrogel system for controlled delivery of anticancer peptide

An electro-chemo-responsive carrier has been engineered for the controlled release of a highly hydrophilic anticancer peptide, CR(NMe)EKA (Cys-Arg- N-methyl-Glu-Lys-Ala). Remotely controlled on demand release of CR(NMe)EKA, loaded in electro-responsive poly(3,4-ethylenedioxythiophene) (PEDOT) nanoparticles, has been achieved by applying electrical stimuli consisting of constant positive (+0.50 V) or negative voltages (-0.50 V) at pre-defined time intervals. In addition, after loading CR(NMe)EKA/PEDOT nanoparticles into an injectable pH responsive hydrogel formed by phenylboronic acid grafted to chitosan (PBA-CS), the efficiency of the controlled peptide release has increased approximately by a factor of 2.6. The hydration ratio of such hydrogel is significantly lower in acidic environments than in neutral and basic media, which has been attributed to the dissociation of the boronate bonds between polymer chains. Hence, the electro-controlled peptide release from PBA-CS/CR(NMe)EKA/PEDOT hydrogels, in the acidic environment of tumors, combines the effects of the oxidation and reduction of PEDOT chains on the interactions with the peptide and the carrier, with the peptide concentration gradient at the interface between the collapsed hydrogel and the release medium. Furthermore, the peptide released by electro-stimulation preserved its bioactivity assessed by promoting human prostate cancer cells death. Overall, this work is a promising attempt to develop a carrier platform for small hydrophilic anticancer peptides, which delivery rationale is synergistically regulated by the electrical and pH responsiveness of the carrier.

Current advances in nanoformulations of therapeutic agents targeting tumor microenvironment to overcome drug resistance

The tumor microenvironment (TME) plays a pivotal role in cancer development and progression. In this line, revealing the precise mechanisms of the TME and associated signaling pathways of tumor resistance could pave the road for cancer prevention and efficient treatment. The use of nanomedicine could be a step forward in overcoming the barriers in tumor-targeted therapy. Novel delivery systems benefit from enhanced permeability and retention effect, decreasing tumor resistance, reducing tumor hypoxia, and targeting tumor-associated factors, including immune cells, endothelial cells, and fibroblasts. Emerging evidence also indicates the engagement of multiple dysregulated mediators in the TME, such as matrix metalloproteinase, vascular endothelial growth factor, cytokines/chemokines, Wnt/β-catenin, Notch, Hedgehog, and related inflammatory and apoptotic pathways. Hence, investigating novel multitargeted agents using a novel delivery system could be a promising strategy for regulating TME and drug resistance. In recent years, small molecules from natural sources have shown favorable anticancer responses by targeting TME components. Nanoformulations of natural compounds are promising therapeutic agents in simultaneously targeting multiple dysregulated factors and mediators of TME, reducing tumor resistance mechanisms, overcoming interstitial fluid pressure and pericyte coverage, and involvement of basement membrane. The novel nanoformulations employ a vascular normalization strategy, stromal/matrix normalization, and stress alleviation mechanisms to exert higher efficacy and lower side effects. Accordingly, the nanoformulations of anticancer monoclonal antibodies and conventional chemotherapeutic agents also improved their efficacy and lessened the pharmacokinetic limitations. Additionally, the coadministration of nanoformulations of natural compounds along with conventional chemotherapeutic agents, monoclonal antibodies, and nanomedicine-based radiotherapy exhibits encouraging results. This critical review evaluates the current body of knowledge in targeting TME components by nanoformulation-based delivery systems of natural small molecules, monoclonal antibodies, conventional chemotherapeutic agents, and combination therapies in both preclinical and clinical settings. Current challenges, pitfalls, limitations, and future perspectives are also discussed.

A Dual Concentration-Tailored Cytokine-Chemo Nanosystem to Alleviate Multidrug Resistance and Redirect Balance of Cancer Proliferation and Apoptosis

Background

Cancer multidrug resistance (MDR) is an important factor that severely affects the chemotherapeutic efficacy. Among various methods to bypass MDR, usage of cytokines, such as tumor necrosis factor alpha (TNFα) is attractive, which exerts antitumor effects of immunotherapeutic response and apoptotic/proinflammatory pathways. Nevertheless, the challenges remain how to implement targeted delivery of TNFα to reduce toxicity and manifest the involved signaling mechanism that subdues MDR.

Methods

We synthesized a multifunctional nanosytem, in which TNFα covalently bound to doxorubicin (Dox)-loaded pH-responsive mesoporous silica nanoparticles (MSN) through bi-functional polyethylene glycol (TNFα-PEG-MSN-Hydrazone-Dox) as a robust design to overcome MDR.

Results

The salient features of this nanoplatform are: 1) by judicious tailoring of TNFα concentration conjugated on MSN, we observed it could lead to a contrary effect of either proliferation or suppression of tumor growth; 2) the MSN-TNFα at higher concentration serves multiple functions, besides tumor targeting and inducer of apoptosis through extrinsic pathway, it inhibits the expression level of p-glycoprotein (P-gp), a cell membrane protein that functions as a drug efflux pump; 3) the enormous surface area of MSN provides for TNFα functionalization, and the nanochannels accommodate chemotherapeutics, Dox; 4) targeted intracellular release of Dox through the pH-dependent cleavage of hydrazone bonds induces apoptosis by the specific intrinsic pathway; and 5) TNFα-PEG-MSN-Hydrazone-Dox (MSN-Dox-TNFα) could infiltrate deep into the 3D spheroid tumor model through disintegration of tight junction proteins. When administered intratumorally in a Dox-resistant mouse tumor model, MSN-Dox-TNFα exhibited a synergistic therapeutic effect through the collective performances of TNFα and Dox.

Conclusion

We hereby develop and demonstrate a multifunctional MSN-Dox-TNFα system with concentration-tailored TNFα that can abrogate the drug resistance mechanism, and significantly inhibit the tumor growth through both intrinsic and extrinsic apoptosis pathways, thus making it a highly potential nanomedicine translated in the treatment of MDR tumors.

Red Blood Cell Membrane Camouflaged Mesoporous Silica Nanorods as Nanocarriers for Synergistic Chemo-Photothermal Therapy

In recent years, nanoparticles camouflaged by red blood cell membrane (RBCM) have become a potential nano-drug delivery platform due to their good biocompatibility and immune evasion capability. Here, a multifunctional drug nanocarrier based on RBCM camouflaged mesoporous silica nanorods (MSNR) is presented, which can be used in pH and near-infrared (NIR) light triggered synergistic chemo-photothermal killing of cancer cells. To fabricate such a nanocarrier, MSNR and RBCM were prepared by the sol-gel method and modified hypotonic lysis method, respectively. Drugs were loaded into the pores of MSNR. Finally, RBCM was coated on the surface of MSNR by extrusion through a polycarbonate membrane. The advantages of the nanocarrier include: 1) MSNR can induce more cellular uptake than sphere shaped mesoporous silica nanoparticles. 2) The RBCM can reduce drug leakage and prevent clearance of the nanocarriers by macrophages. 3) By simultaneous loading doxorubicin (DOX) and indocyanine green (ICG), pH and NIR triggered synergistic chemo-photothermal therapy can be realized. In the experiment, we studied the drug releasing and cellular uptake of the nanocarriers in a breast cancer cell line (SKBR3 cells), in which a sufficient killing effect was observed. Such a multifunctional drug nanocarrier holds a broad application prospect in cancer treatment.

Conquering Cancer Multi-Drug Resistance Using Curcumin and Cisplatin Prodrug-Encapsulated Mesoporous Silica Nanoparticles for Synergistic Chemo- and Photodynamic Therapies

Recently, the development of anti-cancer approaches using different physical or chemical pathways has shifted from monotherapy to synergistic therapy, which can enhance therapeutic effects. As a result, enormous efforts have been devoted to developing various delivery systems encapsulated with dual agents for synergistic effects and to combat cancer cells acquired drug resistance. In this study, we show how to make Institute of Bioengineering and Nanotechnology (IBN)-1-based mesoporous silica nanoparticles (MSNs) for multifunctional drug delivery to overcome drug resistance cancer therapy. Initially, curcumin (Cur)-embedded IBN-1 nanocomposites (IBN-1-Cur) are synthesized in a simple one-pot co-condensation and then immobilized with the prodrug of Cisplatin (CP) on the carboxylate-modified surface (IBN-1-Cur-CP) to achieve photodynamic therapy (PDT) and chemotherapy in one platform, respectively, in the fight against multidrug resistance (MDR) of MES-SA/DX5 cancer cells. The Pluronic F127 triblock copolymer, as the structure-directing agent, in nanoparticles acts as a p-glycoprotein (p-gp) inhibitor. These designed hybrid nanocomposites with excellent structural properties are efficiently internalized by the endocytosis and successfully deliver Cur and CP molecules into the cytosol. Furthermore, the presence of Cur photosensitizer in the nanochannels of MSNs resulted in increased levels of cellular reactive oxygen species (ROS) under light irradiation. Thus, IBN-1-Cur-CP showed excellent anti-cancer therapy in the face of MES-SA/DX5 resistance cancer cells, owing to the synergistic effects of chemo- and photodynamic treatment.

Engineered Mesoporous Silica-Based Core-Shell Nanoarchitectures for Synergistic Chemo-Photodynamic Therapies

Combinatorial therapies have garnered enormous interest from researchers in efficiently devastating malignant tumors through synergistic effects. To explore the combinatorial approach, multiple therapeutic agents are typically loaded in the delivery vehicles, controlling their release profiles and executing subsequent therapeutic purposes. Herein, we report the fabrication of core (silica)-shell (mesoporous silica nanoparticles, MSNs) architectures to deliver methylene blue (MB) and cupric doxorubicin (Dox) as model drugs for synergistic photodynamic therapy (PDT), chemotherapy, and chemodynamic therapy (CDT). MB, as the photosensitizer, is initially loaded and stabilized in the silica core for efficient singlet oxygen generation under light irradiation towards PDT. The most outside shell with imidazole silane-modified MSNs is immobilized with a chemotherapeutic agent of Dox molecules through the metal (Copper, Cu)-ligand coordination interactions, achieving the pH-sensitive release and triggering the production of intracellular hydrogen peroxide and subsequent Fenton-like reaction-assisted Cu-catalyzed free radicals for CDT. Further, the designed architectures are systematically characterized using various physicochemical characterization techniques and demonstrate the potent anti-cancer efficacy against skin melanoma. Together our results demonstrated that the MSNs-based core-shell nanoarchitectures have great potential as an effective strategy in synergistically ablating cancer through chemo-, chemodynamic, and photodynamic therapies.

Engineering mesoporous silica nanoparticles for drug delivery: where are we after two decades?

The present review details a chronological description of the events that took place during the development of mesoporous materials, their different synthetic routes and their use as drug delivery systems. The outstanding textural properties of these materials quickly inspired their translation to the nanoscale dimension leading to mesoporous silica nanoparticles (MSNs). The different aspects of introducing pharmaceutical agents into the pores of these nanocarriers, together with their possible biodistribution and clearance routes, would be described here. The development of smart nanocarriers that are able to release a high local concentration of the therapeutic cargo on-demand after the application of certain stimuli would be reviewed here, together with their ability to deliver the therapeutic cargo to precise locations in the body. The huge progress in the design and development of MSNs for biomedical applications, including the potential treatment of different diseases, during the last 20 years will be collated here, together with the required work that still needs to be done to achieve the clinical translation of these materials. This review was conceived to stand out from past reports since it aims to tell the story of the development of mesoporous materials and their use as drug delivery systems by some of the story makers, who could be considered to be among the pioneers in this area.

Synergistic effect of obeticholic acid and fasting-mimicking on proliferative, migration, and survival signaling in prostate cancer

The systemic and resistant nature of the androgen-independent stage of prostate cancers makes it largely incurable even after intensive multimodal therapy. Apoptosis and epithelial-mesenchymal transition (EMT) are two fundamental events that are deeply linked to carcinogenesis. Hence, it is necessary to find a new combination of several therapies targeting apoptosis and EMT without causing side effects. Several recent studies have indicated that the Farnesoid X receptor is extensively associated with human tumorigenesis. The FXR agonist obeticholic acid (INT 747) has preliminarily exhibited a tumor suppressor potential. In this present study, we assess the potential synergism of FXR activation under nutrient deprivation in prostate cancer cell lines to investigate whether FXR activation enhances starvation-induced apoptosis in PC3 cells. In this study, PC-3 treatment with INT 747 significantly repressed cell proliferation and clonogenic potential. In addition, it significantly induced apoptosis of PC-3 cells and decreased their cancerogenic potential, as evaluated by annexin v apoptosis and transwell migration assay, respectively. The decreased expression of pro-caspase 3 by western blot analysis further confirmed INT 747-induced apoptosis. Furthermore, the fasting-mimicking diet (FMD) potentiated the antiproliferative, pro-apoptotic, and antimetastatic effects of INT 747. Mechanistically, these effects were mediated through the downregulation of cyclin D1 and upregulation of PTEN. In conclusion, INT 747 alone markedly decreases, and when combined with FMD abrogates the growth and migration of PC-3 cells.

Targeting vascular inflammation through emerging methods and drug carriers

Acute inflammation is a common dangerous component of pathogenesis of many prevalent conditions with high morbidity and mortality including sepsis, thrombosis, acute respiratory distress syndrome (ARDS), COVID-19, myocardial and cerebral ischemia-reperfusion, infection, and trauma. Inflammatory changes of the vasculature and blood mediate the course and outcome of the pathology in the tissue site of insult, remote organs and systemically. Endothelial cells lining the luminal surface of the vasculature play the key regulatory functions in the body, distinct under normal vs. pathological conditions. In theory, pharmacological interventions in the endothelial cells might enable therapeutic correction of the overzealous damaging pro-inflammatory and pro-thrombotic changes in the vasculature. However, current agents and drug delivery systems (DDS) have inadequate pharmacokinetics and lack the spatiotemporal precision of vascular delivery in the context of acute inflammation. To attain this level of precision, many groups design DDS targeted to specific endothelial surface determinants. These DDS are able to provide specificity for desired tissues, organs, cells, and sub-cellular compartments needed for a particular intervention. We provide a brief overview of endothelial determinants, design of DDS targeted to these molecules, their performance in experimental models with focus on animal studies and appraisal of emerging new approaches. Particular attention is paid to challenges and perspectives of targeted therapeutics and nanomedicine for advanced management of acute inflammation.

[(WR)8WKβA]-Doxorubicin Conjugate: A Delivery System to Overcome Multi-Drug Resistance against Doxorubicin

Doxorubicin (Dox) is an anthracycline chemotherapeutic agent used to treat breast, leukemia, and lymphoma malignancies. However, cardiotoxicity and inherent acquired resistance are major drawbacks, limiting its clinical application. We have previously shown that cyclic peptide [WR]₉ containing alternate tryptophan (W) and arginine (R) residues acts as an efficient molecular transporter. An amphiphilic cyclic peptide containing a lysine (K) residue and alternative W and R was conjugated through a free side chain amino group with Dox via a glutarate linker to afford [(WR)₈WKβA]-Dox conjugate. Antiproliferative assays were performed in different cancer cell lines using the conjugate and the corresponding physical mixture of the peptide and Dox to evaluate the effectiveness of synthesized conjugate compared to the parent drug alone. [(WR)₈WKβA]-Dox conjugate showed higher antiproliferative activity at 10 µM and 5 µM than Dox alone at 5 μM. The conjugate inhibited the cell viability of ovarian adenocarcinoma (SK-OV-3) by 59% and the triple-negative breast cancer cells MDA-MB-231 and MCF-7 by 71% and 77%, respectively, at a concentration of 5 μM after 72 h of incubation. In contrast, Dox inhibited the proliferation of SK-OV-3, MDA-MB-231, and MCF-7 by 35%, 63%, and 57%, respectively. Furthermore, [(WR)₈WKβA]-Dox conjugate (5 µM) inhibited the cell viability of Dox-resistant cells (MES-SA/MX2) by 92%, while the viability of cells incubated with free Dox was only 15% at 5 μM. Confocal microscopy images confirmed the ability of both Dox conjugate and the physical mixture of the peptide with the drug to deliver Dox through an endocytosis-independent pathway, as the uptake was not inhibited in the presence of endocytosis inhibitors. The stability of Dox conjugate was observed at different time intervals using analytical HPLC when the conjugate was incubated with 25% human serum. Half-life (t_1/2) for [(WR)₈WKβA]-Dox conjugate was (∼6 h), and more than 80% of the conjugate was degraded at 12 h. The release of free Dox was assessed intracellularly using the CCRF-CEM cell line. The experiment demonstrated that approximately 100% of free Dox was released from the conjugate intracellularly within 72 h. These data confirm the ability of the cyclic cell-penetrating peptide containing tryptophan and arginine residues as an efficient tool for delivery of Dox and for overcoming resistance to it.

[(WR)8WKβA]-Doxorubicin Conjugate: A Delivery System to Overcome Multi-Drug Resistance against Doxorubicin

Doxorubicin (Dox) is an anthracycline chemotherapeutic agent used to treat breast, leukemia, and lymphoma malignancies. However, cardiotoxicity and inherent acquired resistance are major drawbacks, limiting its clinical application. We have previously shown that cyclic peptide [WR]9 containing alternate tryptophan (W) and arginine (R) residues acts as an efficient molecular transporter. An amphiphilic cyclic peptide containing a lysine (K) residue and alternative W and R was conjugated through a free side chain amino group with Dox via a glutarate linker to afford [(WR)8WKβA]-Dox conjugate. Antiproliferative assays were performed in different cancer cell lines using the conjugate and the corresponding physical mixture of the peptide and Dox to evaluate the effectiveness of synthesized conjugate compared to the parent drug alone. [(WR)8WKβA]-Dox conjugate showed higher antiproliferative activity at 10 µM and 5 µM than Dox alone at 5 μM. The conjugate inhibited the cell viability of ovarian adenocarcinoma (SK-OV-3) by 59% and the triple-negative breast cancer cells MDA-MB-231 and MCF-7 by 71% and 77%, respectively, at a concentration of 5 μM after 72 h of incubation. In contrast, Dox inhibited the proliferation of SK-OV-3, MDA-MB-231, and MCF-7 by 35%, 63%, and 57%, respectively. Furthermore, [(WR)8WKβA]-Dox conjugate (5 µM) inhibited the cell viability of Dox-resistant cells (MES-SA/MX2) by 92%, while the viability of cells incubated with free Dox was only 15% at 5 μM. Confocal microscopy images confirmed the ability of both Dox conjugate and the physical mixture of the peptide with the drug to deliver Dox through an endocytosis-independent pathway, as the uptake was not inhibited in the presence of endocytosis inhibitors. The stability of Dox conjugate was observed at different time intervals using analytical HPLC when the conjugate was incubated with 25% human serum. Half-life (t1/2) for [(WR)8WKβA]-Dox conjugate was (∼6 h), and more than 80% of the conjugate was degraded at 12 h. The release of free Dox was assessed intracellularly using the CCRF-CEM cell line. The experiment demonstrated that approximately 100% of free Dox was released from the conjugate intracellularly within 72 h. These data confirm the ability of the cyclic cell-penetrating peptide containing tryptophan and arginine residues as an efficient tool for delivery of Dox and for overcoming resistance to it.

Nanoparticles for Triple Drug Release for Combined Chemo- and Photodynamic Therapy

A pH-responsive drug delivery system (DDS) based on mesoporous silica nanoparticles (MSNs) has been prepared for the delivery of three anticancer drugs with different modes of action. The novelty of this system is its ability to combine synergistic chemotherapy and photodynamic therapy. A photoactive conjugate of a phthalocyanine (Pc) and a topoisomerase I inhibitor (topo-I), namely camptothecin (CPT), linked by a poly(ethylene glycol) (PEG) chain has been synthesized and then loaded into the mesopores of MSNs. Doxorubicin (DOX), which is a topoisomerase II inhibitor (topo-II), has also been covalently anchored to the outer surface of the MSNs through a dihydrazide PEG linker. In the acidic environment of tumor cells, selective release of the three drugs takes place. In vitro studies have demonstrated the endocytosis of the system into HeLa and HepG2 cells, and the subsequent release of the three drugs into the cytoplasm and nucleus. Furthermore, the cytotoxic effect of DOX, CPT and Pc has been assessed in vitro before and upon light irradiation.

Microfluidic assembly of pomegranate-like hierarchical microspheres for efflux regulation in oral drug delivery

Herein, a multi-functional nano-in-micro hierarchical microsphere system is demonstrated for controlling the intestinal efflux pumps that affect the oral bioavailability of many therapeutic drugs. The hierarchical particles were generated by a co-flow microfluidic device and consisted of porous silica nanoparticles packed in Eudragit® polymeric matrix. Meropenem (MER), a last-resort antibacterial drug, was loaded into porous silica (MCM-48) with a loading capacity of 34.3 wt%. In this unique materials combination, MCM-48 enables ultrahigh loading of a hydrophilic MER, while the Eudragit® polymers not only protect MER from gastric pH but also act as an antagonist for p-glycoprotein protein efflux pumps to reduce the efflux of MER back into the gastrointestinal lumen. We investigated the in-vitro temporal MER release and bidirectional (absorptive and secretory) drug permeation model across the Caco-2 monolayer. The bioavailability of MER was significantly improved by all of the prepared formulations (i.e. increased absorptive transport and reduced secretory transport). The Eudragit® RSPO formulated MER-MCM showed the best performance with an efflux ratio (i.e. secretory transport/absorptive transport) of 0.35, which is 7.4 folds less than pure MER (2.62). Lastly, the prepared formulations were able to retain the antibacterial activity of MER against Staphylococcus aureus and Pseudomonas aeruginosa. STATEMENT OF SIGNIFICANCE: Meropenem (MER) is a last resort antibiotic used for the treatment of drug-resistant and acute infections and only available as intravenous injectable dosage due to its poor chemical and thermal stability, and ultra-poor oral bioavailability because of the efflux action of P-glycoprotein (P-gp) pumps. Multifunctional colloidal micro/nanoparticles can help to solve these issues. Herein, we designed pomegranate-like hierarchical microspheres comprised of porous silica nanoparticles and enteric Eudragit® polymers (Eudragit®S100, Eudragit®RSPO, and Eudragit®RS100) using a co-flow microfluidic device. Our formulations allow for ultrahigh loading of hydrophilic MER, protects MER from gastric pH, and also block P-gp efflux pumps for enhanced MER permeation/retention with Eudragit®RSPO - showing 13.9-folds higher permeation and 7.4-folds reduction in efflux ratio in a bi-directional Caco-2 monolayer culture system.

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

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

Targeted and stimuli-responsive mesoporous silica nanoparticles for drug delivery and theranostic use

For cancer therapy, the usefulness of mesoporous silica nanoparticles (MPSNPs) has been widely discussed, likely due to its inorganic nature and excellent structural features. The MPSNPs-based chemotherapeutics have been promisingly delivered to their target sites that help to minimize side effects and improve therapeutic effectiveness. A wide array of studies have been conducted to functionalize drug-loaded MPSNPs using targeting ligands and stimuli-sensitive substances. In addition, anticancer drugs have been precisely delivered to their target sites using MPSNPs, which respond to multi-stimuli. Furthermore, MPSNPs have been extensively tested for their safety and compatibility. The toxicity level of MPSNPs is substantially lower as compared to that of colloidal silica; however, in oxidative stress, they exhibit cytotoxic features. The biocompatibility of MPSNPs can be improved by modifying their surfaces. This article describes the production procedures, functionalization, and applications of biocompatible MPSNPs in drug delivery.

Controlled drug delivery systems for cancer based on mesoporous silica nanoparticles

The implementation of nanotechnology in medicine has opened new research horizons particularly in the field of therapeutic delivery. Mesoporous silica particles have emerged as biocompatible drug delivery systems with an enormous potential in the treatment of cancer among many other pathologies. In this review, we focus on the unique properties of these particles as chemotherapy delivery carriers. Here, we summarize the general characteristics of these nanomaterials - including their physicochemical properties and customizable surfaces - different stimuli that can be used to trigger targeted drug release, biocompatibility and finally, the drawbacks of these types of nanomaterials, highlighting some of the most important features of mesoporous silica nanoparticles in drug delivery.

P-glycoprotein-targeted photodynamic therapy boosts cancer nanomedicine by priming tumor microenvironment

Cancer nanomedicines only modestly improve the overall survival of patients because their anticancer activity is limited by biological barriers posed by the tumor microenvironment. Currently, all the drugs in FDA-approved cancer nanomedicines are substrates for P-glycoprotein (Pgp), and thus, Pgp-mediated multidrug resistance (MDR) remains a hurdle for cancer nanomedicines.

Methods: In this study, Pgp-targeted photodynamic therapy (PDT) was developed to enhance the anticancer efficacy of nanomedicines by depleting MDR cancer cells as well as enhancing tumor penetration of nanomedicines. We first examined the Pgp specificity of our targeted PDT approach, and then tested combination therapy of PDT with Doxil in mixed tumor models of MDR cancer cells and stromal cells, mimicking human heterogeneous tumors.

Results: In vitro studies showed that the antibody-photosensitizer conjugates produced Pgp-specific cytotoxicity towards MDR cancer cells upon irradiation with a near-infrared light. The studies with a co-culture model of MDR cancer cells and stromal cells revealed synergistic effects in the combination therapy of PDT with Doxil. Using a mouse model of mixed tumors containing MDR cancer cells and stroma cells, we observed markedly enhanced tumor delivery of Doxil after PDT in vivo. We further examined the effects of the two modalities on individual cell populations and their synergism using an in vivo dual substrate bioluminescence assay. The results indicated that Pgp-targeted PDT specifically depleted MDR cancer cells and further enhanced Doxil's actions on both MDR cancer cells and stromal cells.

Conclusion: We conclude that our targeted PDT approach markedly enhances anticancer actions of nanomedicines by depleting MDR cancer cells and increasing their tumor penetration, and thereby, may provide an effective approach to facilitate translation of cancer nanomedicines.

Mesoporous silica nanoparticles as cutting-edge theranostics: Advancement from merely a carrier to tailor-made smart delivery platform

Large surface area, uniform and tunable pore size, high pore volume and low mass density- such attractive features of Mesoporous silica nanoparticles (MSNPs) have compelled researchers to explore the biomedical potential of this nano-material. Recently gained interest in MSNPs have been due to their tremendous potential in cancer therapy and imaging. Last several years have witnessed a rapid development in engineering functionalized MSNPs with various types of functional groups integrated into the system for imaging and therapeutic applications. Although their potential for drug delivery application has been studied since the year 2000, still a major challenge is to improve drug loading capacity and in vivo targeting with minimal side-effects to major organs. In this review article, the recent development of MSNPs as a therapeutic and diagnostic platform has been detailed out with emphasis on drug and bio-macromolecule delivery/co-delivery, bio-imaging and detoxification.

Light-Activated ROS-Responsive Nanoplatform Codelivering Apatinib and Doxorubicin for Enhanced Chemo-Photodynamic Therapy of Multidrug-Resistant Tumors

Clinical chemotherapy confronts a challenge resulting from cancer-related multidrug resistance (MDR), which can directly lead to treatment failure. To address it, an innovative approach is proposed to construct a light-activated reactive oxygen species (ROS)-responsive nanoplatform based on a protoporphyrin (PpIX)-conjugated and dual chemotherapeutics-loaded polymer micelle. This system combines chemotherapy and photodynamic therapy (PDT) to defeat the MDR of tumors. Such an intelligent nanocarrier can prolong the circulation time in blood because of the negative polysaccharide component of chondroitin sulfate, and subsequently being selectively internalized by MCF-7/ADR cells [doxorubicin (DOX)-resistant]. When exposed to 635 nm red light, this nanoplatform generates sufficient ROS through the photoconversion of PpIX, further triggering the disassociation of the micelles to release the dual cargoes. Afterward, the released apatinib, serving as a reversal inhibitor of MDR, can recover the chemosensitivity of DOX by competitively inhibiting the P-glycoprotein drug pump in drug-resistant tumor cells, and the excessive ROS has a strong capacity to exert its PDT effect to act on the mitochondria or the nuclei, ultimately causing cell apoptosis. As expected, this intelligent nanosystem successfully reverses tumor MDR via the synergism between apatinib-enhanced DOX sensitivity and ROS-mediated PDT performance.

Inhibition of human prostate cancer (PC-3) cells and targeting of PC-3-derived prostate cancer stem cells with koenimbin, a natural dietary compound from Murraya koenigii (L) Spreng

BACKGROUND

Inhibition of prostate cancer stem cells (PCSCs) is an efficient curative maintenance protocol for the prevention of prostate cancer. The objectives of this study were to assess the efficiency of koenimbin, a major biologically active component of Murraya koenigii (L) Spreng, in the suppression of PC-3 cells and to target PC-3-derived cancer stem cells (CSCs) through apoptotic and CSC signaling pathways in vitro.

MATERIALS AND METHODS

The antiproliferative activity of koenimbin was examined using MTT, and the apoptotic detection was carried out by acridine orange/propidium iodide (AO/PI) double-staining and multiparametric high-content screening (HCS) assays. Caspase bioluminescence assay, reverse transcription polymerase chain reaction (RT-PCR), and immunoblotting were conducted to confirm the expression of apoptotic-associated proteins. Cell cycle analysis was investigated using flow cytometry. Involvement of nuclear factor-kappa B (NF-κB) was analyzed using HCS assay. Aldefluor™ and prostasphere formation examinations were used to evaluate the impact of koenimbin on PC-3 CSCs in vitro.

RESULTS

Koenimbin remarkably inhibited cell proliferation in a dose-dependent manner. Koenimbin induced nuclear condensation, formation of apoptotic bodies, and G0/G1 phase arrest of PC-3 cells. Koenimbin triggered the activation of caspase-3/7 and caspase-9 and the release of cytochrome c, decreased anti-apoptotic Bcl-2 and HSP70 proteins, increased pro-apoptotic Bax proteins, and inhibited NF-κB translocation from the cytoplasm to the nucleus, leading to the activation of the intrinsic apoptotic pathway. Koenimbin significantly (P<0.05) reduced the aldehyde dehydrogenase-positive cell population of PC-3 CSCs and the size and number of PC-3 CSCs in primary, secondary, and tertiary prostaspheres in vitro.

CONCLUSION

Koenimbin has chemotherapeutic potential that may be employed for future treatment through decreasing the recurrence of cancer, resulting in the improvement of cancer management strategies and patient survival.

Controlled drug delivery vehicles for cancer treatment and their performance

Although conventional chemotherapy has been successful to some extent, the main drawbacks of chemotherapy are its poor bioavailability, high-dose requirements, adverse side effects, low therapeutic indices, development of multiple drug resistance, and non-specific targeting. The main aim in the development of drug delivery vehicles is to successfully address these delivery-related problems and carry drugs to the desired sites of therapeutic action while reducing adverse side effects. In this review, we will discuss the different types of materials used as delivery vehicles for chemotherapeutic agents and their structural characteristics that improve the therapeutic efficacy of their drugs and will describe recent scientific advances in the area of chemotherapy, emphasizing challenges in cancer treatments.

Improving the delivery of cancer therapies to tumor sites is crucial to reduce unwanted side effects and patient mortality rates. Pralay Maiti and colleagues at the Indian Institute of Technology in Varanasi, India, review the latest developments in drug delivery vehicles and treatment approaches designed to enhance the effectiveness of current cancer therapies. New nanoparticle-based carriers, hydrogels and hybrid materials that offer controlled and sustained drug release are showing great promise in animal models. Furthermore, materials that respond to stimuli such as heat, light, magnetic or electric fields are also being tested to aid target-specific drug delivery and, thus, avoid damage to healthy tissues. Although there are some challenges in translating these findings to the clinic, there is no doubt that technological advances are shaping better and safer treatment options.

Mesoporous silica nanoparticles for drug and gene delivery

Mesoporous silica nanoparticles (MSNs) are attracting increasing interest for potential biomedical applications. With tailored mesoporous structure, huge surface area and pore volume, selective surface functionality, as well as morphology control, MSNs exhibit high loading capacity for therapeutic agents and controlled release properties if modified with stimuli-responsive groups, polymers or proteins. In this review article, the applications of MSNs in pharmaceutics to improve drug bioavailability, reduce drug toxicity, and deliver with cellular targetability are summarized. Particularly, the exciting progress in the development of MSNs-based effective delivery systems for poorly soluble drugs, anticancer agents, and therapeutic genes are highlighted.

Overcoming STC2 mediated drug resistance through drug and gene co-delivery by PHB-PDMAEMA cationic polyester in liver cancer cells

Stanniocalcin 2 (STC2) overexpression in hepatocellular carcinoma (HCC) could lead to poor prognosis, which might be due to its induced P-glycoprotein and Bcl-2 protein expression level increase. P-glycoprotein or membrane pump induced drug efflux and altered prosurvival Bcl-2 expression are key mechanisms for drug resistance leading to failure of chemotherapy in HCC. However, current strategy to overcome both P-glycoprotein and Bcl-2 protein induced drug resistance was rarely reported. In this work, we utilized an amphiphilic poly[(R)-3-hydroxybutyrate] (PHB)-b-poly(2-(dimethylamino)ethyl methacrylate) (PDMAEMA) cationic polyester to encapsulate chemotherapeutic paclitaxel (PTX) in hydrophobic PHB domain and Bcl-2 convertor Nur77/ΔDBD gene (Nur77 without DNA binding domain for mitochondria localization) by formation of polyplex due to cationic PDMAEMA segment, to effectively inhibit the drug resistant HepG2/STC2 and SMCC7721/STC2 liver cancer cell growth. Thanks to the cationic nanoparticle complex formation ability and high transfection efficiency to express Bcl-2 conversion proteins, PHB-PDMAEMA/PTX@polyplex could partially impair P-glycoprotein induced PTX efflux and activate the apoptotic function of previous prosurvival Bcl-2 protein. This is the pioneer report of cationic amphiphilic polyester PHB-PDMAEMA to codeliver anticancer drug and therapeutic plasmid to overcome both pump and non-pump mediated chemotherapeutic resistance in liver cancer cells, which might be inspiring for the application of polyester in personalized cancer therapy.

MDR in cancer: Addressing the underlying cellular alterations with the use of nanocarriers

Multidrug resistance (MDR) is associated with a wide range of pathological changes at different cellular and intracellular levels. Nanoparticles (NPs) have been extensively exploited as the carriers of MDR reversing payloads to resistant tumor cells. However, when properly formulated in terms of chemical composition and physicochemical properties, NPs can serve as beyond delivery systems and help overcome MDR even without carrying a load of chemosensitizers or MDR reversing molecular cargos. Whether serving as drug carriers or beyond, a wise design of the nanoparticulate systems to overcome the cellular and intracellular alterations underlying the resistance is imperative. Within the current review, we will initially discuss the cellular changes occurring in resistant cells and how such changes lead to chemotherapy failure and cancer cell survival. We will then focus on different mechanisms through which nanosystems with appropriate chemical composition and physicochemical properties can serve as MDR reversing units at different cellular and intracellular levels according to the changes that underlie the resistance. Finally, we will conclude by discussing logical grounds for a wise and rational design of MDR reversing nanoparticulate systems to improve the cancer therapeutic approaches.

The autophagic inhibition oral squamous cell carcinoma cancer growth of 16-hydroxy-cleroda-3,14-dine-15,16-olide

16-hydroxycleroda-3, 13-dine-15, 16-olide (HCD) isolated from Polyalthia longifolia possesses numerous biological activities. Previous studies have reported that HCD can block phosphorylation activity of cancer cells to inhibit tumor cell growth, but the anti-tumor activity in oral squamous cell carcinoma is unrevealed. This study investigates the inhibiting effect of HCD on human OSCC cell growth; thereby, developing a new oral cancer drug. In in vitro cultured human OSCC cells (OECM1 and SAS) were employed to test the inhibitory growth of HCD via cell cytotoxic effect using 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) assay, Western blotting, and further determining of the inhibitory efficacy of tumor growth by a xenograft tumor on BALB/c male nude mice (in vivo test). Under various concentrations of HCD and time course treatments were shown to effectively cause cell death and cell-cycle arrest in OECM1 and SAS cells, which was confirmed via a clinical drug (cisplatin) as a positive control. In addition, HCD induced the autophagic cell death in OECM1 and SAS cells by LC3-mediated LC3-I/LC3-II/p62 pathway at the in vitro level. An in vivo assay indicated that HCD could treat oral cancer by deferring tumor growth. These findings provide a favorable assessment for further elucidating the role of HCD that targets autophagic cell death pathways as a potential agent for cancer therapy.

Stimuli-Responsive Mesoporous Silica NPs as Non-viral Dual siRNA/Chemotherapy Carriers for Triple Negative Breast Cancer

Triple negative breast cancer (TNBC) is the most aggressive and lethal subtype of breast cancer. It is associated with a very poor prognosis and intrinsically resistant to several conventional and targeted chemotherapy agents and has a 5-year survival rate of less than 25%. Because the treatment options for TNBC are very limited and not efficient enough for achieving minimum desired goals, shifting toward a new generation of anti-cancer agents appears to be very critical. Among recent alternative approaches being proposed, small interfering RNA (siRNA) gene therapy can potently suppress Bcl-2 proto-oncogene and p-glycoprotein gene expression, the most important chemotherapy resistance inducers in TNBC. When resensitized, primarily ineffective chemotherapy drugs turn back into valuable sources for further intensive chemotherapy. Regrettably, siRNA's poor stability, rapid clearance in the circulatory system, and poor cellular uptake mostly hampers the beneficial outcomes of siRNA therapy. Considering these drawbacks, dual siRNA/chemotherapy drug encapsulation in targeted delivery vehicles, especially mesoporous silica nanoparticles (MSNs) appears to be the most reasonable solution. The literature is full of reports of successful treatments of multi-drug-resistant cancer cells by administration of dual drug/siRNA-loaded MSNs. Here we tried to answer the question of whether application of a similar approach with identical delivery devices in TNBC is rational.

Reversal of paclitaxel resistance in human ovarian cancer cells with redox-responsive micelles consisting of α-tocopheryl succinate-based polyphosphoester copolymers

P-glycoprotein (P-gp)-mediated multidrug resistance (MDR) is a major obstacle in achieving the therapeutic benefits of paclitaxel (PTX) in the treatment of human ovarian carcinoma. This study is aimed to develop an efficient PTX drug delivery approach to overcome MDR. Redox-responsive micelles consisting of amphiphilic polymers containing disulfide linkages, ie, poly (phosphate ester)-SS-D-α-tocopheryl succinate (POPEA-SS-TOS, PSST) were prepared. PTX-loaded PSST micelles (PTX/PSST-M) designed to display synergistic functions, including reversible inhibition of P-gp, intracellular redox-sensitive release and potent anticancer activities. The average size of PTX/PSST-M was 68.1±4.9 nm. The encapsulated PTX was released quickly through redox-triggered dissociation of micelles. The inhibition of P-gp activity and enhanced cellular accumulation of the PSST micelles were validated. PTX/PSST-M showed significantly increased cytotoxicity against PTX-resistant human ovarian cancer A2780/PTX cells: when the cells were treated with PTX/PSST-M for 48 h, the equivalent IC₅₀ value of PTX was reduced from 61.51 to 0.49 μmol/L. The enhanced cytotoxic effects of PTX/PSST-M against A2780/PTX cells were attributed to their synergistic effects on reducing the mitochondrial transmembrane potential, ATP depletion, ROS production, and activation of apoptotic pathways. Furthermore, PTX/PSST-M significantly increased cell apoptosis/necrosis and cell cycle arrest at the G₂/M phase in A2780/PTX cells. These results demonstrate that the redox-responsive PSST micelles inhibit P-gp activity and have a good potential to effectively reverse PTX resistance in human ovarian carcinoma cells by activating intrinsic apoptotic pathways.

Encapsulation of 16-Hydroxycleroda-3,13-Dine-16,15-Olide in Mesoporous Silica Nanoparticles as a Natural Dipeptidyl Peptidase-4 Inhibitor Potentiated Hypoglycemia in Diabetic Mice

Natural supplements comprise good efficacy with less adverse effects as against diabetic therapy, but their advancement as anti-diabetic agents is unsatisfactory with regard to the delivery system. Dipeptidyl peptidase-4 (DPP4)/CD26) can degrade glucagon-like pepetide-1 (GLP-1) which renders a decrease of blood glucose levels. 16-hydroxycleroda-3,13-dine-16,15-olide (HCD) extracted from Polyalthia longifolia, exhibits numerous medicinal potentials including hypoglycemic potential. On consideration of HCD application, the bioavailability is affected by low solubility. Extended experiments of anti-diabetic efficacy confirmed HCD biocompatible with mesoporous silica nanoparticles (MSNs) encapsulation resulted in a sustained release property in delivering HCD for the inhibition of DPP4 via the activity and protein levels of DPP4 analysis. In the enzymatic activity assay, MSN-HCD directly changed DPP4 activity. Moreover, MSN-HCD nanoparticles were treated with Caco-2 cells and the protein levels of DPP4 determined within the cells. The results revealed that MSN-HCD caused reduction of DPP4 activity in a time- and dose-dependent fashion. Orally administered MSN-HCD in diet-induced diabetic mice alleviated blood glucose via an oral glucose tolerance test. In addition, administration of MSN-HCD for five weeks revealed that the biochemical cues such as pyruvate transaminase (GPT), glutamate oxaloacetate transaminase (GOT), triglycerides (TG), cholesterol (CHO), and glycated hemoglobin (HbA1c) in mice were commendable as further confirmation of MSN-HCD efficacy and less adverse effects in down-regulation of hyperglycemia. Furthermore, this formulation effectively controlled blood glucose and significantly decreased the body weight of mice, suggesting that MSN-HCD exerts natural DPP4 inhibitor as a potential clinical drug for the treatment of diabetes.

Titania-coated gold nanorods as an effective carrier for gambogic acid

Titania-coated gold nanorods were used as a carrier for gambogic acid, and the drug-loaded nanoparticles show an enhanced anticancer effect.

Mesoporous silica nanoparticles for stimuli-responsive controlled drug delivery: advances, challenges, and outlook

With the development of nanotechnology, the application of nanomaterials in the field of drug delivery has attracted much attention in the past decades. Mesoporous silica nanoparticles as promising drug nanocarriers have become a new area of interest in recent years due to their unique properties and capabilities to efficiently entrap cargo molecules. This review describes the latest advances on the application of mesoporous silica nanoparticles in drug delivery. In particular, we focus on the stimuli-responsive controlled release systems that are able to respond to intracellular environmental changes, such as pH, ATP, GSH, enzyme, glucose, and H2O2. Moreover, drug delivery induced by exogenous stimuli including temperature, light, magnetic field, ultrasound, and electricity is also summarized. These advanced technologies demonstrate current challenges, and provide a bright future for precision diagnosis and treatment.

Inorganic Nanocarriers Overcoming Multidrug Resistance for Cancer Theranostics

Cancer multidrug resistance (MDR) could lead to therapeutic failure of chemotherapy and radiotherapy, and has become one of the main obstacles to successful cancer treatment. Some advanced drug delivery platforms, such as inorganic nanocarriers, demonstrate a high potential for cancer theranostic to overcome the cancer-specific limitation of conventional low-molecular-weight anticancer agents and imaging probes. Specifically, it could achieve synergetic therapeutic effects, demonstrating stronger killing effects to MDR cancer cells by combining the inorganic nanocarriers with other treatment manners, such as RNA interference and thermal therapy. Moreover, the inorganic nanocarriers could provide imaging functions to help monitor treatment responses, e.g., drug resistance and therapeutic effects, as well as analyze the mechanism of MDR by molecular imaging modalities. In this review, the mechanisms involved in cancer MDR and recent advances of applying inorganic nanocarriers for MDR cancer imaging and therapy are summarized. The inorganic nanocarriers may circumvent cancer MDR for effective therapy and provide a way to track the therapeutic processes for real-time molecular imaging, demonstrating high performance in studying the interaction of nanocarriers and MDR cancer cells/tissues in laboratory study and further shedding light on elaborate design of nanocarriers that could overcome MDR for clinical translation.

Drug-loaded liposome-capped mesoporous core-shell magnetic nanoparticles for cellular toxicity study

Liposome-capped core-shell mesoporous silica-coated superparamagnetic iron oxide nanoparticles called 'magnetic protocells' were prepared as novel nanocomposites and used for loading anticancer drug doxorubicin (DOX) for cellular toxicity study. Cytotoxicity of the magnetic protocells with or without DOX was tested in vitro on commercial MCF7 and U87 cell lines under alternating magnetic field. MCF7 cell line treated with the DOX-loaded nanoparticles under alternating magnetic field exhibited nearly 20% lower survival rate after 24 h compared with cells treated with free DOX and similarly, it was around 24% when applied to U87. The results indicate that the magnetic protocells could be useful for future cancer treatment in vivo by the combination of targeted drug delivery and magnetic hyperthermia.

Hurdles in selection process of nanodelivery systems for multidrug-resistant cancer

PURPOSE

Most of the nanomedicines for treatment of multidrug-resistant cancer do not reach Phase III trials and many are terminated or withdrawn or are in an indeterminate state since long without any study results being presented. Extensive perusal of nanomedicine development research revealed that one of the critical aspects influencing clinical outcomes and which requires diligent scrutiny is selection process of nanodelivery system.

METHODS

Research papers and articles published on development of nanodelivery systems for treatment of multidrug-resistant cancer were analyzed. Observations and conclusions noted by these researchers which might shed some light on poor clinical performance of nanocarriers were collated and summarized under observation section. Further research articles were studied to find possible solutions which may be applied to these particular problems for resolving them. The inferences of these findings were composed in Result section.

RESULT

Plausible solutions for the observed obstacles were noted as examples of novel formulations that can yield the following: better in vivo imaging, precise targeting and dosing of a specific site and specific cell type in a particular cancer, modulation of tumor surroundings, intonation of systemic effects and high reproducibility.

CONCLUSION

The angle of approach to the development of best nanosystem for a specific type of tumor needs to be spun around. Some of these changes can be brought about by individual scientists, some need to be established by collated efforts of scientists globally and some await advent of better technologies. Regardless of the stratagem, it can be said decisively that the schematics of development phase need rethinking.

Reversing Cancer Multidrug Resistance in Xenograft Models via Orchestrating Multiple Actions of Functional Mesoporous Silica Nanoparticles

A multistimuli responsive drug delivery system (DDS) based on sulfhydryl and amino-cofunctionalized mesoporous silica nanoparticles (SH/NH2-MSNs) has been developed, in which the multifunctional hyaluronic acid (HA) derivatives were grafted onto the SH/NH2-MSNs by disulfide bonds for targeting delivery, controlling drug release and reversing multidrug resistance (MDR). The doxorubicin (Dox) loaded multifunctional HA derivatives modified mesoporous silica nanoparticles (Dox/HHS-MSNs) were enzyme and redox sensitive, which could respond to the intracellular stimuli of hyaluronidase (HAase) and glutathione (GSH) successively and prevent drug leakage before reaching the tumor tissues. The cellular uptake experiments showed that Dox/HHS-MSNs were vulnerable to be endocytosed into the Dox-resistant human breast adenocarcinoma (MCF-7/ADR) cells, efficiently realized the endolysosomal escape and remained in the cytoplasm. Because of orchestrating multiple actions above including active targeting, endolysosomal escape and efficient multilevel drug release, Dox/HHS-MSNs could induce the strongest apoptosis and cytotoxicity of MCF-7/ADR cells. Furthermore, a series of in vivo studies on MCF-7/ADR tumor-bearing xenograft mouse models demonstrated that Dox/HHS-MSNs possessed the enhanced tumor-targeting capacity and the best therapeutic efficacy to reverse cancer MDR.