A review of polysaccharide cytotoxic drug conjugates for cancer therapy

Prodrug-based nanomedicines for rheumatoid arthritis

Most antirheumatic drugs with high toxicity exhibit a narrow therapeutic window due to their nonspecific distribution in the body, leading to undesirable side effects and reduced patient compliance. To in response to these challenges, prodrug-based nanoparticulate drug delivery systems (PNDDS), which combines prodrug strategy and nanotechnology into a single system, resulting their many advantages, including stability for prodrug structure, the higher drug loading capacity of the system, improving the target activity and bioavailability, and reducing their untoward effects. PNDDS have gained attention as a method for relieving arthralgia syndrome of rheumatoid arthritis in recent years. This article systematically reviews prodrug-based nanocarriers for rheumatism treatment, including Nano systems based on prodrug-encapsulated nanomedicines and conjugate-based nanomedicines. It provides a new direction for the clinical treatment of rheumatoid arthritis.

Plant-derived polyphenolic compounds: nanodelivery through polysaccharide-based systems to improve the biological properties

Plant-derived polyphenols are naturally occurring compounds widely distributed in plants. They have received greater attention in the food and pharmaceutical industries due to their potential health benefits, reducing the risk of some chronic diseases due to their antioxidant, anti-inflammatory, anticancer, cardioprotective, and neuro-action properties. Polyphenolic compounds orally administered can be used as adjuvants in several treatments but with restricted uses due to chemical instability. The review discusses the different structural compositions of polyphenols and their influence on chemical stability. Despite the potential and wide applications, there is a need to improve the delivery of polyphenolics to target the human intestine without massive chemical modifications. Oral administration of polyphenols is unfeasible due to instability, low bioaccessibility, and limited bioavailability. Nano-delivery systems based on polysaccharides (starch, pectin, chitosan, and cellulose) have been identified as a viable option for oral ingestion, potentiate biological effects, and direct-controlled delivery in specific tissues. The time and dose can be individualized for specific diseases, such as intestinal cancer. This review will address the mechanisms by which polysaccharides-based nanostructured systems can protect against degradation and enhance intestinal permeation, oral bioavailability, and the potential application of polysaccharides as nanocarriers for the controlled and targeted delivery of polyphenolic compounds.

Preparation of injectable hydrophilic dextran/AgNPs nanocomposite product: White light active biomolecules as an antitumor agent

Incidence of various cancers including melanoma continues to rise worldwide. While treatment options have expanded in the recent years, the benefit of these treatments suffer from short period of duration for many patients. Hence, new treatment options are highly desired. Here, we propose a method combining a Dextran/reactive-copolymer/AgNPs nanocomposite and a harmless visible light approach to obtain a plasma substitute carbohydrate-based nanoproduct (D@AgNP) that shows strong antitumor activity. Light-driven polysaccharide-based nanocomposite provided essential conditions for extra small (8-12nm) AgNPs capping with subsequent specific self-assembly into spherical-like cloud nanostructures. Obtained biocompatible D@AgNP are stable over six months at room temperature and demonstrated absorbance peak at 406 nm. New formulated nanoproduct revealed efficient anticancer properties against A375 with IC50 0.0035 mg/mL following 24-h incubation; complete cell death is achieved at 0.001 mg/mL and 0.0005 mg/mL by 24- and 48-h time points, respectively. SEM examination shows that D@AgNP altered the shape of the cell structure and damaged the cell membrane. TEM finding shows that D@AgNP are mostly localized at vesicles such as the endosomes, lysosomes and mitochondria. It is anticipated that the introduced new method serves as the cornerstone for improving the generation of biocompatible hydrophilic carbohydrate-based anticancer drugs.

Nanozymes with Peroxidase-like Activity for Ferroptosis-Driven Biocatalytic Nanotherapeutics of Glioblastoma Cancer: 2D and 3D Spheroids Models

Glioblastoma (GBM) is the most common primary brain cancer in adults. Despite the remarkable advancements in recent years in the realm of cancer diagnosis and therapy, regrettably, GBM remains the most lethal form of brain cancer. In this view, the fascinating area of nanotechnology has emerged as an innovative strategy for developing novel nanomaterials for cancer nanomedicine, such as artificial enzymes, termed nanozymes, with intrinsic enzyme-like activities. Therefore, this study reports for the first time the design, synthesis, and extensive characterization of innovative colloidal nanostructures made of cobalt-doped iron oxide nanoparticles chemically stabilized by a carboxymethylcellulose capping ligand (i.e., Co-MION), creating a peroxidase-like (POD) nanozyme for biocatalytically killing GBM cancer cells. These nanoconjugates were produced using a strictly green aqueous process under mild conditions to create non-toxic bioengineered nanotherapeutics against GBM cells. The nanozyme (Co-MION) showed a magnetite inorganic crystalline core with a uniform spherical morphology (diameter, 2R = 6-7 nm) stabilized by the CMC biopolymer, producing a hydrodynamic diameter (H_D) of 41-52 nm and a negatively charged surface (ZP~-50 mV). Thus, we created supramolecular water-dispersible colloidal nanostructures composed of an inorganic core (Cox-MION) and a surrounding biopolymer shell (CMC). The nanozymes confirmed the cytotoxicity evaluated by an MTT bioassay using a 2D culture in vitro of U87 brain cancer cells, which was concentration-dependent and boosted by increasing the cobalt-doping content in the nanosystems. Additionally, the results confirmed that the lethality of U87 brain cancer cells was predominantly caused by the production of toxic cell-damaging reactive oxygen species (ROS) through the in situ generation of hydroxyl radicals (·OH) by the peroxidase-like activity displayed by nanozymes. Thus, the nanozymes induced apoptosis (i.e., programmed cell death) and ferroptosis (i.e., lipid peroxidation) pathways by intracellular biocatalytic enzyme-like activity. More importantly, based on the 3D spheroids model, these nanozymes inhibited tumor growth and remarkably reduced the malignant tumor volume after the nanotherapeutic treatment (ΔV~40%). The kinetics of the anticancer activity of these novel nanotherapeutic agents decreased with the time of incubation of the GBM 3D models, indicating a similar trend commonly observed in tumor microenvironments (TMEs). Furthermore, the results demonstrated that the 2D in vitro model overestimated the relative efficiency of the anticancer agents (i.e., nanozymes and the DOX drug) compared to the 3D spheroid models. These findings are notable as they evidenced that the 3D spheroid model resembles more precisely the TME of "real" brain cancer tumors in patients than 2D cell cultures. Thus, based on our groundwork, 3D tumor spheroid models might be able to offer transitional systems between conventional 2D cell cultures and complex biological in vivo models for evaluating anticancer agents more precisely. These nanotherapeutics offer a wide avenue of opportunities to develop innovative nanomedicines for fighting against cancerous tumors and reducing the frequency of severe side effects in conventionally applied chemotherapy-based treatments.

Recent advances in pH/enzyme-responsive polysaccharide-small-molecule drug conjugates as nanotherapeutics

Now-a-days, the polysaccharides are extensively employed for the delivery of small-molecule drugs ascribed to their excellent biocompatibility, biodegradability and modifiability. An array of drug molecules is often chemically conjugated with different polysaccharides to augment their bio-performances. As compared to their therapeutic precursors, these conjugates could typically demonstrate an improved intrinsic solubility, stability, bioavailability and pharmacokinetic profiles of the drugs. In current years, various stimuli-responsive particularly pH and enzyme-sensitive linkers or pendants are also exploited to integrate the drug molecules into the polysaccharide backbone. The resulting conjugates could experience a rapid molecular conformational change upon exposure to the microenvironmental pH and enzyme changes of the diseased states, triggering the release of the bioactive cargos at the targeted sites and eventually minimize the systemic side effects. Herein, the recent advances in pH and enzyme -responsive polysaccharide-drug conjugates and their therapeutic benefits are systematically reviewed, following a brief description on the conjugation chemistry of the polysaccharides and drug molecules. The challenges and future perspectives of these conjugates are also precisely discussed.

Polymer-drug conjugates: Design principles, emerging synthetic strategies and clinical overview

Adagen, an enzyme replacement treatment for adenosine deaminase deficiency, was the first protein-polymer conjugate to be approved in early 1990s. Post this regulatory approval, numerous polymeric drugs and polymeric nanoparticles have entered the market as advanced or next-generation polymer-based therapeutics, while many others have currently been tested clinically. The polymer conjugation to therapeutic moiety offers several advantages, like enhanced solubilization of drug, controlled release, reduced immunogenicity, and prolonged circulation. The present review intends to highlight considerations in the design of therapeutically effective polymer-drug conjugates (PDCs), including the choice of linker chemistry. The potential synthetic strategies to formulate PDCs have been discussed along with recent advancements in the different types of PDCs, i.e., polymer-small molecular weight drug conjugates, polymer-protein conjugates, and stimuli-responsive PDCs, which are under clinical/preclinical investigation. Current impediments and regulatory hurdles hindering the clinical translation of PDC into effective therapeutic regimens for the amelioration of disease conditions have been addressed.

Near-Infrared Fluorescence Tumor-Targeted Imaging in Lung Cancer: A Systematic Review

Lung cancer is the most common cancer type worldwide, with non-small cell lung cancer (NSCLC) being the most common subtype. Non-disseminated NSCLC is mainly treated with surgical resection. The intraoperative detection of lung cancer can be challenging, since small and deeply located pulmonary nodules can be invisible under white light. Due to the increasing use of minimally invasive surgical techniques, tactile information is often reduced. Therefore, several intraoperative imaging techniques have been tested to localize pulmonary nodules, of which near-infrared (NIR) fluorescence is an emerging modality. In this systematic review, the available literature on fluorescence imaging of lung cancers is presented, which shows that NIR fluorescence-guided lung surgery has the potential to identify the tumor during surgery, detect additional lesions and prevent tumor-positive resection margins.

Insight on structural modification, biological activity, structure-activity relationship of PPD-type ginsenoside derivatives

Ginsenosides, characterized by triterpenoid, are one of the active components of ginseng. Among them, PPD-type ginsenosides have potent and diverse pharmacological activities, while the effective applications and clinical studies are limited by the poor stability, water solubility and oral bioavailability. In this review, we have attempted to demonstrate the structural-activity relationship of chemical modifications on the dammarane-type skeleton and the C-17 side chain, noting that certain structurally modified derivatives exhibit satisfactory pharmacological activity. This review will provide ideas for the design and synthesis of novel PPD derivatives, and valuable help for the further study of PPD derivatives to make it realize clinical application.

Enhancing cisplatin anticancer effectivity and migrastatic potential by modulation of molecular weight of oxidized dextran carrier

The molecular weight (M_w) of dextran derivatives, such as regioselectively oxidized dicarboxydextran (DXA), is greatly influencing their faith in an organism, which could be possibly used to improve anticancer drug delivery. Here we present a modified method of sulfonation-induced chain scission allowing direct and accurate control over the M_w of DXA without increasing its polydispersity. Prepared DXA derivatives (M_w = 10-185 kDa) have been conjugated to cisplatin and the M_w of the carrier found to have a significant impact on cisplatin release rates, in vitro cytotoxicity, and migrastatic potential. Conjugates with the high-M_w DXA showed particularly increased anticancer efficacy. The best conjugate was four times more effective against malignant prostatic cell lines than free cisplatin and significantly inhibited the ovarian cancer cell migration. This was traced to the characteristics of spontaneously formed cisplatin-crosslinked DXA nanogels influenced by M_w of DXA and amount of loaded cisplatin.

Biopolymer and Synthetic Polymer-Based Nanocomposites in Wound Dressing Applications: A Review

Biopolymers are materials obtained from a natural origin, such as plants, animals, microorganisms, or other living beings; they are flexible, elastic, or fibrous materials. Polysaccharides and proteins are some of the natural polymers that are widely used in wound dressing applications. In this review paper, we will provide an overview of biopolymers and synthetic polymer-based nanocomposites, which have promising applications in the biomedical research field, such as wound dressings, wound healing, tissue engineering, drug delivery, and medical implants. Since these polymers have intrinsic biocompatibility, low immunogenicity, non-toxicity, and biodegradable properties, they can be used for various clinical applications. The significant advancements in materials research, drug development, nanotechnology, and biotechnology have laid the foundation for changing the biopolymeric structural and functional properties. The properties of biopolymer and synthetic polymers were modified by blending them with nanoparticles, so that these materials can be used as a wound dressing application. Recent wound care issues, such as tissue repairs, scarless healing, and lost tissue integrity, can be treated with blended polymers. Currently, researchers are focusing on metal/metal oxide nanomaterials such as zinc oxide (ZnO), cerium oxide (CeO₂), silver (Ag), titanium oxide (TiO₂), iron oxide (Fe₂O₃), and other materials (graphene and carbon nanotubes (CNT)). These materials have good antimicrobial properties, as well as action as antibacterial agents. Due to the highly antimicrobial properties of the metal/metal oxide materials, they can be used for wound dressing applications.

Thiolated-Polymer-Based Nanoparticles as an Avant-Garde Approach for Anticancer Therapies-Reviewing Thiomers from Chitosan and Hyaluronic Acid

Thiomers (or thiolated polymers) have broken through as avant-garde approaches in anticancer therapy. Their distinguished reactivity and properties, closely linked to their final applications, justify the extensive research conducted on their preparation and use as smart drug-delivery systems (DDSs). Multiple studies have demonstrated that thiomer-rich nanoformulations can overcome major drawbacks found when administering diverse active pharmaceutical ingredients (APIs), especially in cancer therapy. This work focuses on providing a complete and concise review of the synthetic tools available to thiolate cationic and anionic polymers, in particular chitosan (CTS) and hyaluronic acid (HA), respectively, drawing attention to the most successful procedures. Their chemical reactivity and most relevant properties regarding their use in anticancer formulations are also discussed. In addition, a variety of NP formation procedures are outlined, as well as their use in cancer therapy, particularly for taxanes and siRNA. It is expected that the current work could clarify the main synthetic strategies available, with their scope and drawbacks, as well as provide some insight into thiomer chemistry. Therefore, this review can inspire new research strategies in the development of efficient formulations for the treatment of cancer.

Chitosan-based blends for biomedical applications

Polysaccharides are the most abundant naturally available carbohydrate polymers; composed of monosaccharide units covalently connected together. Chitosan is the most widely used polysaccharides because of its exceptional biocompatibility, mucoadhesion, and chemical versatility. However, it suffers from a few drawbacks, e.g. poor mechanical properties and antibacterial activity for biomedical applications. Blending chitosan with natural or synthetic polymers may not merely improve its physicochemical and mechanical properties, but may also improve its bioactivity-induced properties. This review paper summarizes progress in chitosan blends with biodegradable polymers and polysaccharides and their biomedical applications. Blends of chitosan with alginate, starch, cellulose, pectin and dextran and their applications were particularly addressed. The critical and challenging aspects as well as the future ahead of the use of chitosan-based blends were eventually enlightened.

Supramolecular magnetonanohybrids for multimodal targeted therapy of triple-negative breast cancer cells

Despite the undeniable advances in recent decades, cancer remains one of the deadliest diseases of the current millennium, where the triple-negative breast cancer (TNBC) is very aggressive, extremely metastatic, and resistant to conventional chemotherapy. The nanotheranostic approach focusing on targeting membrane receptors often expressed at abnormal levels by cancer cells can be a strategic weapon for fighting malignant tumors. Herein, we introduced a novel "all-in-one nanosoldier" made of colloidal hybrid nanostructures, which were designed for simultaneously targeting, imaging, and killing TNBC cells. These nanohybrids comprised four distinct components: (a) superparamagnetic iron oxide nanoparticles, as bi-functional nanomaterials for inducing ferroptosis via inorganic nanozyme-mediated catalysis and magnetotherapy by hyperthermia treatment; (b) carboxymethyl cellulose biopolymer, as a water-soluble capping macromolecule; (c) folic acid, as the membranotopic vector for targeting folate receptors; (d) and doxorubicin (DOX) drug for chemotherapy. The results demonstrated that this novel strategy was highly effective for targeting and killing TNBC cells in vitro, expressing high levels of folate membrane-receptors. The results evidenced that three integrated mechanisms triggered the deaths of the cancer cells in vitro: (a) ferroptosis, by magnetite nanoparticles inducing a Fenton-like reaction; (b) magneto-hyperthermia effect by generating heat under an alternate magnetic field; and (c) chemotherapy, through the DOX intracellular release causing DNA dysfunction. This "all-in-one nanosoldier" strategy offers a vast realm of prospective alternatives for attacking cancer cells, combining multimodal therapy and the delivery of therapeutic agents to diseased sites and preserving healthy cells, which is one of the most critical clinical challenges faced in fighting drug-resistant breast cancers.

Oxidized polysaccharides for anticancer-drug delivery: What is the role of structure?

Study provides an in-depth analysis of the structure-function relationship of polysaccharide anticancer drug carriers and points out benefits and potential drawbacks of differences in polysaccharide glycosidic bonding, branching and drug binding mode of the carriers. Cellulose, dextrin, dextran and hyaluronic acid have been regioselectively oxidized to respective dicarboxylated derivatives, allowing them to directly conjugate cisplatin, while preserving their major structural features intact. The structure of source polysaccharide has crucial impact on conjugation effectiveness, carrier capacity, drug release rates, in vitro cytotoxicity and cellular uptake. For example, while branched structure of dextrin-based carrier partially counter the undesirable initial burst release, it also attenuates the cellular uptake and the cytotoxicity of carried drug. Linear polysaccharides containing β-(1→4) glycosidic bonds and oxidized at C2 and C3 (cellulose and hyaluronate) have the best overall combination of structural features for improved drug delivery applications including potentiation of the cisplatin efficacy towards malignances.

Doxorubicin delivery systems based on doped CaCO3 cores and polyanion drug conjugates

In order to prolong the release and reduce the toxicity of anticancer drug - doxorubicin (DOX), delivery systems (DS) using different polyanions have been developed. Structural (size, morphological stability) and functional (encapsulation efficiency, DOX release) characteristics of three types of DS are compared: CaCO₃ porous vaterites doped with polyanions by co-precipitation and coating techniques, and DOX-polyanion conjugates. Using scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS), it was shown that the doping enhances the morphological stability of CaCO₃-based DS during the DOC loading. Doping of CaCO₃ cores by co-precipitation reduces its sizes (up to 1 µm) and DOX encapsulation efficiency. Polyanion-coated CaCO₃ cores and polyanion drug conjugates show about 98 w/w% DOX encapsulation. For the first time, it was shown that the release of DOX from developed DS into human blood plasma is more intense (from 1.3 to 3.0 times for different DS) than into model tumour environment.

Self-assembly of amphiphilic copolymers containing polysaccharide: PISA versus nanoprecipitation, and the temperature effect

The self-assembly methods and the temperature have a considerable impact on the morphology of the resulting nanoobjects in the case of amphiphilic glycopolymers.

Marine Polysaccharides in Pharmaceutical Applications: Fucoidan and Chitosan as Key Players in the Drug Delivery Match Field

The use of marine-origin polysaccharides has increased in recent research because they are abundant, cheap, biocompatible, and biodegradable. These features motivate their application in nanotechnology as drug delivery systems; in tissue engineering, cancer therapy, or wound dressing; in biosensors; and even water treatment. Given the physicochemical and bioactive properties of fucoidan and chitosan, a wide range of nanostructures has been developed with these polysaccharides per se and in combination. This review provides an outline of these marine polysaccharides, including their sources, chemical structure, biological properties, and nanomedicine applications; their combination as nanoparticles with descriptions of the most commonly used production methods; and their physicochemical and biological properties applied to the design of nanoparticles to deliver several classes of compounds. A final section gives a brief overview of some biomedical applications of fucoidan and chitosan for tissue engineering and wound healing.

Doxorubicin-Loaded Delta Inulin Conjugates for Controlled and Targeted Drug Delivery: Development, Characterization, and In Vitro Evaluation

Delta inulin, also known as microparticulate inulin (MPI), was modified by covalently attaching doxorubicin to its nanostructured surface for use as a targeted drug delivery vehicle. MPI is readily endocytosed by monocytes, macrophages, and dendritic cells and in this study, we sought to utilize this property to develop a system to target anti-cancer drugs to lymphoid organs. We investigated, therefore, whether MPI could be used as a vehicle to deliver doxorubicin selectively, thereby reducing the toxicity of this antibiotic anthracycline drug. Doxorubicin was covalently attached to the surface of MPI using an acid–labile linkage to enable pH-controlled release. The MPI-doxorubicin conjugate was characterized using FTIR and SEM, confirming covalent attachment and indicating doxorubicin coupling had no obvious impact on the physical nanostructure, integrity, and cellular uptake of the MPI particles. To simulate the stability of the MPI-doxorubicin in vivo, it was stored in artificial lysosomal fluid (ALF, pH 4.5). Although the MPI-doxorubicin particles were still visible after 165 days in ALF, 53% of glycosidic bonds in the inulin particles were hydrolyzed within 12 days in ALF, reflected by the release of free glucose into solution. By contrast, the fructosidic bonds were much more stable. Drug release studies of the MPI-doxorubicin in vitro, demonstrated a successful pH-dependent controlled release effect. Confocal laser scanning microscopy studies and flow cytometric analysis confirmed that when incubated with live cells, MPI-doxorubicin was efficiently internalized by immune cells. An assay of cell metabolic activity demonstrated that the MPI carrier alone had no toxic effects on RAW 264.7 murine monocyte/macrophage-like cells, but exhibited anti-cancer effects against HCT116 human colon cancer cells. MPI-doxorubicin had a greater anti-cancer cell effect than free doxorubicin, particularly when at lower concentrations, suggesting a drug-sparing effect. This study establishes that MPI can be successfully modified with doxorubicin for chemotherapeutic drug delivery.

Self-associating cellulose-graft-poly(ε-caprolactone) to design nanoparticles for drug release

The growing interest in the use of polysaccharides nanoparticles for biomedical applications is related to the recent progresses on the synthesis of cellulose-based polymers with the specific functionalities. In particular, cellulose graft copolymers are emerging as amphiphilic materials suitable to fabricate smart nanoparticles for drug delivery applications. In this work, a cellulose-graft-poly(ε-caprolactone) (cell-g-PCL) was synthetized and characterized by FTIR, TGA and DSC in order to validate the synthesis process. We demonstrated that fast evaporation processes promoted cell-g-PCL self-assembly to form nanomicellar structures with hydrodynamic radius ranged from 30 to 60 nm as confirmed by TEM analysis. Moreover, the application of controlled electrostatic forces on solvent evaporation - namely electrospraying - allowed generating round-like nanoscaled particles, as confirmed by SEM supported via image analysis. We demonstrated also that sodium diclofenac (DS) drastically influenced the mechanism of particle formation, favoring the deposition of erythrocyte-like particles with highly concave surfaces, not penalizing the encapsulation efficiency of nanoparticles (>80%). The release profile showed a fast delivery of DS - about 60% during the first 24 h - followed by a sustained release - about 20% during the next 6 days - strictly related to the peculiar weak interactions among amphiphilic polymer segments and water molecules, thus suggesting a successful use of electrosprayed cell-g-PCL nanoparticles for therapeutic treatments in nanomedicine.

Present Scenario of Bioconjugates in Cancer Therapy: A Review

Cancer is one of the deadliest diseases and poses a risk to people all over the world. Surgery, chemo, and radiation therapy have been the only options available until today to combat this major problem. Chemotherapeutic drugs have been used for treatment for more than 50 years. Unfortunately, these drugs have inherent cytotoxicities and tumor cells have started inducing resistance against these drugs. Other common techniques such as surgery and radiotherapy have their own drawbacks. Therefore, such techniques are incompetent tools to alleviate the disease efficiently without any adverse effects. This scenario has inspired researchers to develop alternative techniques with enhanced therapeutic effects and minimal side effects. Such techniques include targeted therapy, liposomal therapy, hormonal therapy, and immunotherapy, etc. However, these therapies are expensive and not effective enough. Furthermore, researchers have conjugated therapeutic agents or drugs with different molecules, delivery vectors, and/or imaging modalities to combat such problems and enhance the therapeutic effect. This conjugation technique has led to the development of bioconjugation therapy, in which at least one molecule is of biological origin. These bioconjugates are the new therapeutic strategies, having prospective synergistic antitumor effects and have potency to overcome the complications being produced by chemo drugs. Herein, we provide an overview of various bioconjugates developed so far, as well as their classification, characteristics, and targeting approach for cancer. Additionally, the most popular nanostructures based on their organic or inorganic origin (metallic, magnetic, polymeric nanoparticles, dendrimers, and silica nanoparticles) characterized as nanocarriers are also discussed. Moreover, we hope that this review will provide inspiration for researchers to develop better bioconjugates as therapeutic agents.

Anti-cervical carcinoma effect of Portulaca oleracea L. polysaccharides by oral administration on intestinal dendritic cells

BACKGROUND

Cervical cancer is the second most prevalent cancer worldwide. Portulaca oleracea L. polysaccharide (POL-P3b) has been found to have enhancing immune and anti-cervical cancer activity by oral administration. Dendritic cells (DC) play a key roles in regulating intestinal immune homeostasis. In this study, we analyzed the inhibition apoptosis effects of POL-P3b on intestinal DC and relevant mechanisms.

METHODS

Intestinal DC was isolated from U14-bearing mice treated with POL-P3b (50 mg/kg, 100 mg/kg and 200 mg/kg, respectively). The effects of POL-P3b on proliferation and inhibiting apoptosis in intestinal DC were evaluated by MTT assay, Hoechst 33342 and Annexin V-FITC/PI staining. Mitochondrial Ca²⁺ was analyzed using flow cytometry instrument. The potential mechanisms underlying POL-P3b-induced protection of intestinal DC from cervical cancer-induced apoptosis were detected with Western blotting evaluation of expression levels of TLR4 and relevant proteins for apoptotic signaling pathway.

RESULTS

We found that a large number of intestinal DC were apoptosis in U14-bearing mice. Treatment with POL-P3b in U14-bearing mice at different doses for 12 d resulted in a significant increase in intestinal DC survival, and the mechanisms were related to inhibiting DC apoptosis.

CONCLUSION

Our results suggested that POL-P3b-induced protection against tumor-induced intestinal DC apoptosis through stimulating the TLR4-PI3K/AKT-NF-κB signaling pathway. This study enhanced understanding of the oral administration with POL-P3b exerted on anti-tumor activity and its action mechanism.

Hexyl alginate derivative, an amphiphilic innovative buccal film-forming material of promising mechanical and release characteristics for the improvement of repaglinide bioavailability

BACKGROUND

Association of long hydrocarbon chain with alginate molecule imparts surface active properties and increases chain flexibility.

PURPOSE

This work studied the efficacy of synthesized hexyl alginate derivative as a film-forming material with unique amphiphilic and mechanical properties for the preparation of rapidly disintegrating repaglinide oral films with higher drug release rate and improved bioavailability.

METHODS

Alginate hexyl amide derivative was prepared and used in the formulation of oral films by solvent casting technique. Using Box-Behnken experimental design, formulations were optimized at different polymer, plasticizer, and disintegrant levels as independent variables for maximum drug release rate, higher tensile strength, and shortest disintegration time as responses. Optimized film formulae were fully evaluated and subjected to further in vivo bioavailability studies in rabbits.

RESULTS

Higher dependency of response results on the selected variables was observed. Optimized formula showed satisfactory tensile strength (145.862 g/cm2), rapid disintegration (22.2 seconds), and higher drug release rate (97.799% within 30 minutes). The drug bioavailability was significantly improved in comparison with plain drug and conventional alginate oral films, where the AUC and Cmax values reached 296.072 μg.h/mL and 116.932 μg/mL in comparison with 164.917 μg.h/mL and 56.568 μg/mL for alginate film and 95.368 μg.h/mL and 31.925 μg/mL for plain drug, respectively. Tmax also showed significant reduction to be only 30 minutes in comparison with 60 minutes for other forms.

CONCLUSION

This led to the final conclusion that the synthesized alginate derivative is an innovative promising film-forming material with unique mechanical and drug release properties for application in buccal drug delivery especially of Biopharmaceutics Classification System (BCS) class II drugs to increase solubility and improve bioavailability.

Kinase Inhibitors of Novel Pyridopyrimidinone Candidates: Synthesis and In Vitro Anticancer Properties

A new class of pyridopyrimidinone compounds containing different nitrogenous heterocycles were synthesized starting from the key precursor 2-hydrazinyl-5-phenyl-7-(pyridin-3-yl)pyrido[2,3-d]pyrimidin-4(3H)-one via condensation with series of aromatic aldehydes and cyclization using different reagents as ethyl acetoacetate, ethyl cyanoacetate, diethyl malonate, and ammonium isothiocyanate. The bioassay results showed compound 6 to be highly effective towards three human cancer cell lines (HepG2, PC-3, and HCT-116) in vitro with promising activity values (IC50: 0.5 μM) relative to the standard doxorubicin (IC50: 0.6 μM). Kinase inhibitory evaluation of compound 6 displays hopeful inhibitory action against BRAF V600E, EGFR, and PDGFRβ at100 μM. The molecular docking studies supported the initial kinase assay.

Sugar-based biopolymers as novel imaging agents for molecular magnetic resonance imaging

Sugar-based biopolymers have been recognized as attractive materials to develop macromolecule- and nanoparticle-based cancer imaging and therapy. However, traditional biopolymer-based imaging approaches rely on the use of synthetic or isotopic labeling, and because of it, clinical translation often is hindered. Recently, a novel magnetic resonance imaging (MRI) technology, chemical exchange saturation transfer (CEST), has emerged, which allows the exploitation of sugar-based biopolymers as MRI agents by their hydroxyl protons-rich nature. In the study, we reviewed recent studies on the topic of CEST MRI detection of sugar-based biopolymers. The CEST MRI property of each biopolymer was briefly introduced, followed by the pre-clinical and clinical applications. The findings of these preliminary studies imply the enormous potential of CEST detectable sugar-based biopolymers in developing highly sensitive and translatable molecular imaging agents and constructing image-guided biopolymer-based drug delivery systems. This article is categorized under: Diagnostic Tools > in vivo Nanodiagnostics and Imaging Therapeutic Approaches and Drug Discovery > Emerging Technologies.

pH/redox dual-sensitive platinum (IV)-based micelles with greatly enhanced antitumor effect for combination chemotherapy

To achieve precise control of nano-carrier structure and drug release behavior, we designed a pH/redox dual-responsive polymeric prodrug by condensation polymerization using octahedrally coordinated cisplatin (Pt IV) and ortho ester monomer. The prodrug was then self-assembled with doxorubicin (DOX) in aqueous solution to give a synergetic drug delivery system. The polymer backbone can completely degrade and release cisplatin (Pt II) and DOX under the acidic and reductive environment of tumor cells, owing to the breakage of ortho ester bonds and the reduction of Pt (IV). The size and micromorphology of micelles were observed by dynamic light scattering (DLS) and transmission electron microscopy (TEM). In vitro study of drug release, cellular uptake and cytotoxicity revealed that the micelles could be triggered intracellularly to release two drugs. In vivo drug distribution and antitumor activity also provide the evidence for the excellent antitumor effect of micelles.

Glutathione responsive chitosan-thiolated dextran conjugated miR-145 nanoparticles targeted with AS1411 aptamer for cancer treatment

miR-145 is a tumor suppressive miRNA which is abnormally reduced in different cancers. miR-145 overexpression reduces cancer migration, invasion, and cell adhesion. Increasing miR-145 level using suitable and efficient gene delivery systems could be valuable in cancer treatment. In this study, a redox-responsive miR-145 conjugated thiolated dextran (TD-miR) was prepared. Also, polyelectrolyte complexes (PECs) of TD-miR and chitosan were fabricated and decorated with anti nucleolin aptamer, AS1411 (apt-PEC). The size of the PECs was between 40-270 nm, and the zeta potential was varied according to the TD-miR to chitosan molar ratio. The outcomes of cellular studies indicated the excellence of the apt-PEC as a duel targeted delivery system and the PECs composed of chitosan 18 kDa with TD-miR to chitosan ratio of 5. TD-miR and the PECs are appropriate as the smart gene delivery systems which preserve and transfect the cargo and release it in cytoplasm.

Design, characterization, and in vitro antiproliferative efficacy of gemcitabine conjugates based on carboxymethyl glucan

Gemcitabine (GEM) is widely used in clinical practice in the treatment of cancer and several other solid tumors. Nevertheless, the antitumor effect of GEM is partially prevented by some limitations including short half life, and lack of tumor localizing. Carboxymethyl glucan (CMG), a carboxymethylated derivative of β-(1-3)-glucan, shows biocompatibility and biodegradability as well as a potential anticarcinogenic effect. To enhance the antiproliferative activity of GEM, four water soluble conjugates of GEM bound to CMG via diverse amino acid linkers were designed and synthesized. ¹H NMR, FT IR, elementary analysis and RP-HPLC chromatography were employed to verify the correct achievement of the conjugates. In vitro release study indicated that conjugates presented slower release in physiological buffer (pH 7.4) than acidic buffer (pH 5.5) mimicking the acidic tumor microenvironment. Moreover, A549, HeLa and Caco-2 cancer cell lines were used to evaluate the in vitro cytotoxicity of conjugates and the results showed that binding GEM to CMG significantly enhanced antiproliferative activity of GEM on A549 cells. Therefore, these conjugates may be potentially useful as a delivery vehicle in cancer therapy and worthy of further study on structure-activity relationship and antiproliferative activity in vitro and in vivo, especially for lung tumor.

Molecular Insights of Hyaluronic Acid as Potential Source of Polymer-Drug Conjugate in the Target-Mediated Treatment of Cancer

The naturally occurring polysaccharide hyaluronic acid (HA) is a major component of the extracellular matrix and is found over expressed in many cancer cells. Hyaluronic acid is reported to be a potential carrier for drug delivery with the dual advantage of accumulation at the tumor site and receptor-mediated uptake. The use of drugs conjugated with macromolecules was shown to improve the drug pharmacokinetic profile. The various biological potentials such as biodegradability, biocompatibility, non-toxicity, hydrophilicity and non-immunogenicity, together with the availability of various chemical groups that allow the conjugation of drugs, put forward HA as a potential choice for the development of drug conjugates. In this context, the present study is focused to provide, through docking studies, insights on the activity of cancer drugs such as methotrexate, 3′,5′-dichloromethotrexate and ornithine-methotrexate and their activity against the receptor caspase-1, which is a well-established drug target in the treatment of cancer. The docking study envisages that the usage of methotrexate properly conjugated to the natural polysaccharide HA might serve as a potential drug to effectively treat some cancer diseases.

Synthesis and antitumor evaluation of hybrids of 5,8-dioxo-5,8-dihydroisoquinoline-4-carboxylates and carbohydrates

Aim: Cancer has emerged as a growing public health problem in many parts of the world. Methodology: We describe the synthesis of a series of carbohydrate-based isoquinoline-5,8-diones through the 1,4-addition reaction between 5,8-dioxo-5,8-dihydroisoquinoline and aminocarbohydrates. Halogenated quinones were also synthesized. Their inhibitory effects on the proliferation of human cancer cell lines were studied. Results & conclusion: The most promising compound, derived from isoquinoline-5,8-dione, containing ribofuranosidyl ring, was selectively active in vitro against H1299 cancer cells, with 1.7-fold higher activity than that of vinorelbine tartrate. This result suggests that the glycoconjugate in question may constitute a valuable lead compound to design and synthesize a more active and less toxic derivative with respect to the development of a new antitumor substance.

New utilization of Polygonum multiflorum polysaccharide as macromolecular carrier of 5-fluorouracil for controlled release and immunoprotection

WPMP-2 is an acid polysaccharide isolated from Polygonum multiflorum, which demonstrated excellent immunomodulatory activity. In order to reduce immunosuppression of 5-fluorouracil (5-Fu), WPMP-2 was utilized as a macromolecular carrier to conjugate the 5-Fu derivatives 5-fluorouracil-1-acetic acid (5-FUAC) through ester bond. The conjugate showed controlled drug release behaviour in vitro at 37°C in phosphate buffer (pH7.4), and only 5-FUAC was detected in the media. The cytotoxicity test in vitro showed that the conjugate exhibited different cytotoxicity to HepG-2 and HT-29 cells. In addition, immunization study in vivo illustrated that the conjugate displayed immunoprotective effect by mitigating inhibition and damage effects of 5-Fu on secretion of cytokines, proliferation of splenocytes, and phagocytosis of peritoneal macrophages. It was indicated that the conjugation of 5-Fu and WPMP-2 could be a potential double effective drug delivery system.

Mannan-based conjugates as a multimodal imaging platform for lymph nodes

We show that mannan-based conjugates possess exceptional features for multimodal imaging because of their biocompatibility, biodegradability and self-targeting properties. Two new mannan conjugates, containing a gadolinium complex and a fluorescent probe, one based only on polysaccharide and the other one comprising polysaccharide with poly(2-methyl-2-oxazoline) grafts, were prepared and simultaneously visualized in vitro and in vivo by magnetic resonance and fluorescence imaging. The synthesis of these mannan-based complexes was based on alkylation with allyl bromide or grafting with poly(2-methyl-2-oxazoline) chains, followed by a thiol-ene click reaction with cysteamine to introduce primary amino groups into their structure. Finally, the obtained conjugates were functionalized with contrast labels using the corresponding N-hydroxysuccinimide esters. When used to detect lymph nodes, the polymers showed better imaging properties than a commercially available contrast agent.

Combined use of insoluble β-glucan from the cell wall of Candida albicans and cyclophosphamide: Validation in S180 tumor-bearing mice

BACKGROUND

Cyclophosphamide (CTX) is a widely used antitumor drug that can suppress the immune system. The effects of regulating immune response and antitumor of β-glucan from the cell wall of Candida albicans (CAIBG) have been confirmed. However, the effects of the combined use of CAIBG and CTX remain unclear and warrant further investigation.

METHODS

S180 tumor-bearing models were developed for CAIBG (100 mg/10 mL/kg) and CTX (30 mg/10 mL/kg) intervention. The weights of the body, tumor spleen, and Thymus were recorded to calculate the index of the spleen and Thymus. The spleen and Thymus were observed by hematoxylin and eosin staining, whereas the expression of tumor necrosis factor (TNF)-α and interleukin (IL)-1β was determined by Western blot. The survival times of mice were followed and recorded for analysis.

RESULTS

CAIBG, CTX, and combined use of CAIBG and CTX could down-regulate the tumor growth and prolong the survival time. The spleen and Thymus index significantly increased in the CAIBG + CTX group than in the CTX group, but it was lower than that in the CAIBG group. Moreover, the Thymus index was significantly lower in the CAIBG + CTX group than in the CAIBG group. The lymphocytes of the spleen and Thymus decreased significantly in the CTX group but improved significantly in the CAIBG and CAIBG + CTX groups. The expression level of TNF-α and IL-1β in the CTX+CAIBG group increased significantly compared with that in the CTX group. The survival time of the CAIBG group and CAIBG + CTX group was significantly higher than that of the CTX group.

CONCLUSIONS

CAIBG has strong treatment potential in combating tumor growth and prolonging survival time of S180 tumor-bearing mice. Combined use of CAIBG and CTX can compensate the CTX-induced immunosuppression and provide antitumor effects. Future studies are necessary to elucidate the underlying mechanism.

Novel apigenin-loaded sodium hyaluronate nano-assemblies for targeting tumor cells

We aimed to construct a novel nano-assembly carrying apigenin (APG), a hydrophobic drug, and to evaluate its in vitro targeting ability for A549 cells overexpressing CD44 receptors. The apigenin-loaded sodium hyaluronate nano-assemblies (APG/SH-NAs) were assembled by multiple non-covalent interactions between sodium hyaluronate (SH) and APG. The prepared APG/SH-NAs exhibited a small average size and narrow particle size distribution. In addition, satisfactory encapsulation efficiency and drug loading were obtained. The drug release curves indicated that APG/SH-NAs achieved a sustainable drug-release effect due to the presence of hydrophilic materials. The in vitro cytotoxicity of APG/SH-NAs against A549 cells and HepG2 cells was evaluated, and the results indicated that the prepared APG/SH-NA showed higher cytotoxicity compared to apigenin suspensions. When CD44 receptors on the surface of A549 cells were blocked by the addition of excess SH, the cytotoxicity of APG/SH-NA was significantly reduced. However, similar phenomena were not observed in HepG2 cells with relatively low CD44 receptor expression. The resulting APG/SH-NAs could efficiently facilitate the internalization of APG into A549 cells, which might be due to their high affinity for CD44 receptors. Moreover, the apoptotic rate of APG/SH-NAs through receptor-mediated endocytosis mechanism was higher than that of the other groups in A549 cells. Thus, such nano-assemblies were considered to be an effective transport system with excellent affinity for CD44 receptors to allow the SH-mediated targeted delivery of APG.

Molecular Insights of Hyaluronic Acid as Potential Source of Polymer-Drug Conjugate in the Target-Mediated Treatment of Cancer

The naturally occurring polysaccharide hyaluronic acid (HA) is a major component of the extracellular matrix and is found over expressed in many cancer cells. Hyaluronic acid is reported to be a potential carrier for drug delivery with the dual advantage of accumulation at the tumor site and receptor-mediated uptake. The use of drugs conjugated with macromolecules was shown to improve the drug pharmacokinetic profile. The various biological potentials such as biodegradability, biocompatibility, non-toxicity, hydrophilicity and non-immunogenicity, together with the availability of various chemical groups that allow the conjugation of drugs, put forward HA as a potential choice for the development of drug conjugates. In this context, the present study is focused to provide, through docking studies, insights on the activity of cancer drugs such as methotrexate, 3′,5′-dichloromethotrexate and ornithine-methotrexate and their activity against the receptor caspase-1, which is a well-established drug target in the treatment of cancer. The docking study envisages that the usage of methotrexate properly conjugated to the natural polysaccharide HA might serve as a potential drug to effectively treat some cancer diseases.

Toxicity, Biocompatibility, pH-Responsiveness and Methotrexate Release from PVA/Hyaluronic Acid Cryogels for Psoriasis Therapy

Poly(vinyl alcohol)/hyaluronic acid cryogels loaded with methotrexate were studied. The physical⁻chemical characterization of cryogels was performed by FT-IR spectroscopy, scanning electron microscopy, differential scanning calorimetry and dynamic mechanical thermal analysis. Acute toxicity and haematological parameters were determined by "in vivo" tests. The biocompatibility tests proved that the obtained cryogels showed significantly decreased toxicity and are biocompatible. The pH-responsiveness of the swelling behaviour and of the methotrexate release from the poly(vinyl alcohol)/hyaluronic acid (PVA/HA) cryogels were studied in a pH interval of 2⁻7.4. A significant change in properties was found at pH 5.5 specific for treatment of affected skin in psoriasis disease.