Polysaccharides for the Delivery of Antitumor Drugs

Identification of Bletilla striata and related decoction pieces: a data fusion method combining electronic nose, electronic tongue, electronic eye, and high-performance liquid chromatography data

Introduction: We here describe a new method for distinguishing authentic Bletilla striata from similar decoctions (namely, Gastrodia elata, Polygonatum odoratum, and Bletilla ochracea schltr). Methods: Preliminary identification and analysis of four types of decoction pieces were conducted following the Chinese Pharmacopoeia and local standards. Intelligent sensory data were then collected using an electronic nose, an electronic tongue, and an electronic eye, and chromatography data were obtained via high-performance liquid chromatography (HPLC). Partial least squares discriminant analysis (PLS-DA), support vector machines (SVM), and back propagation neural network (BP-NN) models were built using each set of single-source data for authenticity identification (binary classification of B. striata vs. other samples) and for species determination (multi-class sample identification). Features were extracted from all datasets using an unsupervised approach [principal component analysis (PCA)] and a supervised approach (PLS-DA). Mid-level data fusion was then used to combine features from the four datasets and the effects of feature extraction methods on model performance were compared. Results and Discussion: Gas chromatography-ion mobility spectrometry (GC-IMS) showed significant differences in the types and abundances of volatile organic compounds between the four sample types. In authenticity determination, the PLS-DA and SVM models based on fused latent variables (LVs) performed the best, with 100% accuracy in both the calibration and validation sets. In species identification, the PLS-DA model built with fused principal components (PCs) or fused LVs had the best performance, with 100% accuracy in the calibration set and just one misclassification in the validation set. In the PLS-DA and SVM authenticity identification models, fused LVs performed better than fused PCs. Model analysis was used to identify PCs that strongly contributed to accurate sample classification, and a PC factor loading matrix was used to assess the correlation between PCs and the original variables. This study serves as a reference for future efforts to accurately evaluate the quality of Chinese medicine decoction pieces, promoting medicinal formulation safety.

Polysaccharide-Based Coatings as Drug Delivery Systems

Therapeutic polysaccharide-based coatings have recently emerged as versatile strategies to transform a conventional medical implant into a drug delivery system. However, the translation of these polysaccharide-based coatings into the clinic as drug delivery systems still requires a deeper understanding of their drug degradation/release profiles. This claim is supported by little or no data. In this review paper, a comprehensive description of the benefits and challenges generated by the polysaccharide-based coatings is provided. Moreover, the latest advances made towards the application of the most important representative coatings based on polysaccharide types for drug delivery are debated. Furthermore, suggestions/recommendations for future research to speed up the transition of polysaccharide-based drug delivery systems from the laboratory testing to clinical applications are given.

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.

Marine Biomaterials: Hyaluronan

The marine-derived hyaluronic acid and other natural biopolymers offer exciting possibilities in the field of biomaterials, providing sustainable and biocompatible alternatives to synthetic materials. Their unique properties and abundance in marine sources make them valuable resources for various biomedical and industrial applications. Due to high biocompatible features and participation in biological processes related to tissue healing, hyaluronic acid has become widely used in tissue engineering applications, especially in the wound healing process. The present review enlightens marine hyaluronan biomaterial providing its sources, extraction process, structures, chemical modifications, biological properties, and biocidal applications, especially for wound healing/dressing purposes. Meanwhile, we point out the future development of wound healing/dressing based on hyaluronan and its composites and potential challenges.

Traversing the diverse avenues of exopolysaccharides-based nanocarriers in the management of cancer

Exopolysaccharides are unique polymers generated by living organisms such as algae, fungi and bacteria to protect them from environmental factors. After a fermentative process, these polymers are extracted from the medium culture. Exopolysaccharides have been explored for their anti-viral, anti-bacterial, anti-tumor, and immunomodulatory effects. Specifically, they have acquired massive attention in novel drug delivery strategies owing to their indispensable properties like biocompatibility, biodegradability, and lack of irritation. Exopolysaccharides such as dextran, alginate, hyaluronic acid, pullulan, xanthan gum, gellan gum, levan, curdlan, cellulose, chitosan, mauran, and schizophyllan exhibited excellent drug carrier properties. Specific exopolysaccharides, such as levan, chitosan, and curdlan, have demonstrated significant antitumor activity. Moreover, chitosan, hyaluronic acid and pullulan can be employed as targeting ligands decorated on nanoplatforms for effective active tumor targeting. This review shields light on the classification, unique characteristics, antitumor activities and nanocarrier properties of exopolysaccharides. In addition, in vitro human cell line experiments and preclinical studies associated with exopolysaccharide-based nanocarriers have also been highlighted.

Biopolymer-Based Nanogel Approach in Drug Delivery: Basic Concept and Current Developments

Due to their increased surface area, extent of swelling and active substance-loading capacity and flexibility, nanogels made from natural and synthetic polymers have gained significant interest in scientific and industrial areas. In particular, the customized design and implementation of nontoxic, biocompatible, and biodegradable micro/nano carriers makes their usage very feasible for a range of biomedical applications, including drug delivery, tissue engineering, and bioimaging. The design and application methodologies of nanogels are outlined in this review. Additionally, the most recent advancements in nanogel biomedical applications are discussed, with particular emphasis on applications for the delivery of drugs and biomolecules.

Carbohydrate ligands-directed active tumor targeting of combinatorial chemotherapy/phototherapy-based nanomedicine: A review

Phototherapies or light mediated therapies, including mutually photothermal and photodynamic therapy that encompass irradiation of the target organs with light, have been widely employed as minimally invasive approach associated with negligible drug resistance for eradicating multiple tumors with minimal hazards to normal organs. Despite all these advantages, many obstacles in phototherapy hinder progress toward clinical application. Therefore, researchers have developed nano-particulate delivery systems integrated with phototherapy and therapeutic cytotoxic drugs to overcome these obstacles and achieve maximum efficacy in cancer treatment. Active targeting ligands were integrated into their surfaces to improve the selectivity and tumor targeting ability, enabling easy binding and recognition by cellular receptors overexpressed on the tumor tissue compared to normal ones. This enhances intratumoral accumulation with minimal toxicity on the adjacent normal cells. Various active targeting ligands, including antibodies, aptamers, peptides, lactoferrin, folic acid and carbohydrates, have been explored for the targeted delivery of chemotherapy/phototherapy-based nanomedicine. Among these ligands, carbohydrates have been applied due to their unique features that ameliorate the bioadhesive, noncovalent conjugation to biological tissues. In this review, the up-to-date techniques of employing carbohydrates active targeting ligands will be highlighted concerning the surface modification of the nanoparticles for ameliorating the targeting ability of the chemo/phototherapy.

Bacterial polysaccharides-A big source for prebiotics and therapeutics

Bacterial polysaccharides are unique due to their higher purity, hydrophilic nature, and a finer three-dimensional fibrous structure. Primarily, these polymers provide protection, support, and energy to the microorganism, however, more recently several auxiliary properties of these biopolymers have been unmasked. Microbial polysaccharides have shown therapeutic abilities against various illnesses, augmented the healing abilities of the herbal and Western medicines, improved overall health of the host, and have exerted positive impact on the growth of gut dwelling beneficial bacteria. Specifically, the review is discussing the mechanism through which bacterial polysaccharides exert anti-inflammatory, antioxidant, anti-cancer, and anti-microbial properties. In addition, they are holding promising application in the 3D printing. The review is also discussing a perspective about the metagenome-based screening of polysaccharides, their integration with other cutting-edge tools, and synthetic microbiome base intervention of polysaccharides as a strategy for prebiotic intervention. This review has collected interesting information about the bacterial polysaccharides from Google Scholar, PubMed, Scopus, and Web of Science databases. Up to our knowledge, this is the first of its kind review article that is summarizing therapeutic, prebiotics, and commercial application of bacterial polysaccharides.

Microbial polysaccharides: An emerging family of natural biomaterials for cancer therapy and diagnostics

Microbial polysaccharides (MPs) offer immense diversity in structural and functional properties. They are extensively used in advance biomedical science owing to their superior biodegradability, hemocompatibility, and capability to imitate the natural extracellular matrix microenvironment. Ease in tailoring, inherent bio-activity, distinct mucoadhesiveness, ability to absorb hydrophobic drugs, and plentiful availability of MPs make them prolific green biomaterials to overcome the significant constraints of cancer chemotherapeutics. Many studies have demonstrated their application to obstruct tumor development and extend survival through immune activation, apoptosis induction, and cell cycle arrest by MPs. Synoptic investigations of MPs are compulsory to decode applied basics in recent inclinations towards cancer regimens. The current review focuses on the anticancer properties of commercially available and newly explored MPs, and outlines their direct and indirect mode of action. The review also highlights cutting-edge MPs-based drug delivery systems to augment the specificity and efficiency of available chemotherapeutics, as well as their emerging role in theranostics.

Carbohydrate Polymer-Based Targeted Pharmaceutical Formulations for Colorectal Cancer: Systematic Review of the Literature

Colon cancer is the third most diagnosed cancer worldwide, followed by lung and breast cancer. Conventional treatment methods are associated with numerous side effects and compliance issues. Thus, colon targeted drug delivery has gained much attention due to its evident advantages. Although many technologies have been explored, the use of pH-sensitive polymers, especially biodegradable polymers, holds exceptional promise. This review aims to collate research articles concerning recent advances in this area. A systematic search using multiple databases (Google Scholar, EMBASE, PubMed, MEDLINE and Scopus) was carried out following the preferred reported items for systematic reviews and meta-analyses (PRISMA) guidelines with an aim to explore the use of pH-sensitive carbohydrate polymers in developing colon targeted pharmaceutical formulations. Following screening and quality assessment for eligibility, 42 studies were included, exploring either single or a combination of carbohydrate polymers to develop targeted formulations for colon cancer therapy. Pectin (11) is the most widely used of these biopolymers, followed by chitosan (09), alginate (09) and guar gum (08). This systematic review has successfully gathered experimental evidence highlighting the importance of employing carbohydrate polymers in developing targeting formulations to manage colon cancer.

miRacle of microRNA-Driven Cancer Nanotherapeutics

MicroRNAs (miRNAs) are non-protein-coding RNA molecules 20-25 nucleotides in length that can suppress the expression of genes involved in numerous physiological processes in cells. Accumulating evidence has shown that dysregulation of miRNA expression is related to the pathogenesis of various human diseases and cancers. Thus, stragegies involving either restoring the expression of tumor suppressor miRNAs or inhibiting overexpressed oncogenic miRNAs hold potential for targeted cancer therapies. However, delivery of miRNAs to tumor tissues is a challenging task. Recent advances in nanotechnology have enabled successful tumor-targeted delivery of miRNA therapeutics through newly designed nanoparticle-based carrier systems. As a result, miRNA therapeutics have entered human clinical trials with promising results, and they are expected to accelerate the transition of miRNAs from the bench to the bedside in the next decade. Here, we present recent perspectives and the newest developments, describing several engineered natural and synthetic novel miRNA nanocarrier formulations and their key in vivo applications and clinical trials.

Xanthan and alginate-matrix used as transdermal delivery carrier for piroxicam and ketoconazole

This study presents new drug delivery systems based on xanthan, unmodified or modified by esterification with oleic acid, and alginate for controlled release of bioactive substances with anti-inflammatory (piroxicam) and antifungal properties (ketoconazole). The mechanical properties of the developed drug carriers showed that their compressive strength was affected by the encapsulation of the bioactive principles. When ketoconazole was added into the xanthan/alginate matrix, an increment in the mechanical strength was recorded (66.68% compression). The release of the active principles from the materials was best described by the Korsmeyer-Peppas model, with non-Fickian or Fickian diffusion (the values of the exponent of release are between 0.29 and 0.75), depending on the composition of the polymeric matrix. The release rate constant presents smaller values for the materials based on chemically modified xanthan (between 0.89 and 20.11) as compared with materials based on the unmodified form (between 4.27 and 25.00). All materials were characterized by Fourier Transform Infrared Spectroscopy (FTIR) and Scanning Electron Microscopy (SEM). The designed systems prove to have antimicrobial and anti-inflammatory activity. The findings make prone these biomaterials for the manufacture of transdermal drug delivery systems.

Nano-strategies as Oral Drug Delivery Platforms for Treatment of Cancer: Challenges and Future Perspectives

Oral drug administration is the oldest and widely used method for drug administration. The objectives behind developing an oral drug delivery for the treatment of cancer are to achieve low cost treatment by utilizing novel techniques to target cancer through gut-associated lymphoid tissue (GALT) and to enhance patient comfort and compliance through a hospital-free treatment leading to "Chemotherapy at Home." Unfortunately, due to the physiological environment of the GIT and physicochemical properties of drug candidate, the efficacy of oral drug delivery methods is limited in the treatment of cancer. Due to their low hydrophilicity, high P-gp efflux and restricted intestinal permeability most of the anti-cancer drugs fail to achieve oral bioavailability. The review focuses on the efforts, challenges, opportunities and studies conducted by scientists worldwide on the oral administration of anticancer medications via nanocarriers such as liposomes, SLNs and dendrimers, because of their potential to overcome the epithelial barrier associated with GALT, as well as the applications of different polymers in targeting the cancer. The oral delivery can set newer horizons in cancer therapy to make it more patient friendly.

Antimicrobial polysaccharides obtained from natural sources

With the increase in resistance to conventional antibiotics among bacterial pathogens, the search for new antimicrobials becomes more and more necessary. Although most studies focus on the discovery of antimicrobial peptides for the development of new antibiotics, several others in the literature have described polysaccharides with the same biological activity with the potential for use as therapeutic alternatives. Here we review the currently available literature on antimicrobial polysaccharides isolated from different sources to demonstrate that there are several possible unconventional carbohydrate polymers that could act as therapeutic alternatives in the battle against drug-resistant pathogens.

An Overview of siRNA Delivery Strategies for Urological Cancers

The treatment of urological cancers has been significantly improved in recent years. However, for the advanced stages of these cancers and/or for those developing resistance, novel therapeutic options need to be developed. Among the innovative strategies, the use of small interfering RNA (siRNA) seems to be of great therapeutic interest. siRNAs are double-stranded RNA molecules which can specifically target virtually any mRNA of pathological genes. For this reason, siRNAs have a great therapeutic potential for human diseases including urological cancers. However, the fragile nature of siRNAs in the biological environment imposes the development of appropriate delivery systems to protect them. Thus, ensuring siRNA reaches its deep tissue target while maintaining structural and functional integrity represents one of the major challenges. To reach this goal, siRNA-based therapies require the development of fine, tailor-made delivery systems. Polymeric nanoparticles, lipid nanoparticles, nanobubbles and magnetic nanoparticles are among nano-delivery systems studied recently to meet this demand. In this review, after an introduction about the main features of urological tumors, we describe siRNA characteristics together with representative delivery systems developed for urology applications; the examples reported are subdivided on the basis of the different delivery materials and on the different urological cancers.

Effect of chest physiotherapy on cystic fibrosis sputum nanostructure: an experimental and theoretical approach

Cystic fibrosis (CF) is a disease characterized by the production of viscous mucoid secretions in multiple organs, particularly the airways. The pathological increase of proteins, mucin and biological polymers determines their arrangement into a three-dimensional polymeric network, affecting the whole mucus and impairing the muco-ciliary clearance which promotes inflammation and bacterial infection. Thus, to improve the efficacy of the drugs usually applied in CF therapy (e.g., mucolytics, anti-inflammatory and antibiotics), an in-depth understanding of the mucus nanostructure is of utmost importance. Drug diffusivity inside a gel-like system depends on the ratio between the diffusing drug molecule radius and the mesh size of the network. Based on our previous findings, we propose the combined use of rheology and low field NMR to study the mesh size distribution of the sputum from CF patients. Specifically, we herein explore the effects of chest physiotherapy on CF sputum characteristic as evaluated by rheology, low field NMR and the drug penetration through the mucus via mathematical simulation. These data show that chest physiotherapy has beneficial effects on patients, as it favourably modifies sputum and enhances drug penetration through the respiratory mucus.

Cellulose Acetate-g-Polycaprolactone Copolymerization Using Diisocyanate Intermediates and the Effect of Polymer Chain Length on Surface, Thermal, and Antibacterial Properties

The need for biodegradable and biocompatible polymers is growing quickly, particularly in the biomedical and environmental industries. Cellulose acetate, a natural polysaccharide, can be taken from plants and modified with polycaprolactone to improve its characteristics for a number of uses, including biomedical applications and food packaging. Cellulose acetate-g-polycaprolactone was prepared by a three-step reaction: First, polymerization of ε-caprolactone via ring-opening polymerization (ROP) reaction using 2-hydroxyethyl methacrylate (HEMA) and functionalization of polycaprolactone(PCL) by introducing NCO on the hydroxyl end of the HEMA-PCL using hexamethyl lenediisocyanate(HDI) were carried out. Then, the NCO–HEMA-PCL was grafted onto cellulose acetate (using the “grafting to” method). The polycaprolactone grafted cellulose acetate was confirmed by FTIR, the thermal characteristics of the copolymers were investigated by DSC and TGA, and the hydrophobicity was analyzed via water CA measurement. Introducing NCO-PCL to cellulose acetate increased the thermal stability. The contact angle of the unreacted PCL was higher than that of cellulose acetate-g-PCL, and it increased when the chain length increased. The CA-g-PCL50, CA-g-PCL100, and CA-g-PCL200 showed very high inhibition zones for all three bacteria tested (E. coli, S. aureus, and P. aeruginosa).

Enhanced Anticancer Activity of Nedaplatin Loaded onto Copper Nanoparticles Synthesized Using Red Algae

Marine algae are a rich source of biologically active compounds that can be utilized in various food and pharmaceutical applications. In this study, ultrasound-assisted extraction (UAE) was optimized to maximize yield and total carbohydrate content extracted from the red algae, Pterocladia capillacea. The extract was shown to possess potent antioxidant activity of up to ~70%, and was successfully used as a reducing and capping agent in the green synthesis of copper nanoparticles, which were characterized by UV-spectroscopy, Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), transmission electron microscopy (TEM), and dynamic light scattering (DLS). Primarily, CuO nanoparticles with an average size of 62 nm were produced. FTIR spectra for the extract and algal-mediated CuO nanoparticles showed characteristic polysaccharide peaks. The synthesized CuO nanoparticles were subsequently loaded with nedaplatin where UV data suggested a complex formation. Nedaplatin release profiles showed a sustained release that reached a maximum at 120 h. The formulation was shown to have greater cytotoxicity relative to nedaplatin on hepatocellular carcinoma, breast cancer and ovarian cancer cell lines with IC50 values of 0.40 ± 0.08, 1.50 ± 0.12, and 0.70 ± 0.09 µg/mL, respectively. Loading nedaplatin onto CuO nanoparticles synthesized using red algae extract, greatly enhances its anticancer effect.

Biomaterials from the sea: Future building blocks for biomedical applications

Marine resources have tremendous potential for developing high-value biomaterials. The last decade has seen an increasing number of biomaterials that originate from marine organisms. This field is rapidly evolving. Marine biomaterials experience several periods of discovery and development ranging from coralline bone graft to polysaccharide-based biomaterials. The latter are represented by chitin and chitosan, marine-derived collagen, and composites of different organisms of marine origin. The diversity of marine natural products, their properties and applications are discussed thoroughly in the present review. These materials are easily available and possess excellent biocompatibility, biodegradability and potent bioactive characteristics. Important applications of marine biomaterials include medical applications, antimicrobial agents, drug delivery agents, anticoagulants, rehabilitation of diseases such as cardiovascular diseases, bone diseases and diabetes, as well as comestible, cosmetic and industrial applications.

Industrial biotransformations catalyzed by microbial lipases: screening platform and commercial aspects

The successfulness of a lipase-catalyzed industrial process depends on a proper lipase selection. In this work, an alternative screening platform for industrially important biotransformations catalyzed by microbial lipases was proposed. Thus, the reactivity of sixty lipase activities from spore-forming microorganisms towards hydrolytic and transesterification reactions by using p-nitrophenyl palmitate as a chromogenic acyl donor substrate was explored. Only three biocatalysts were capable of catalyzing all reactions tested. Fourteen biocatalysts did not show hydrolytic activity at all; however, they displayed transesterification activities using ethanol, starch, low-methoxyl (LM) pectin, high-methoxyl (HM) pectin, or vitamin C as acyl acceptors. Using heat-treated biocatalysts, hydrolytic activities were not highly correlated with the corresponding transesterification activities using ethanol (r =  -0.058, p = 0.660), starch (r = 0.431, p = 0.001), LM pectin (r =  -0.010, p = 0.938), HM pectin (r = 0.167, p = 0.202), and vitamin C (r =  -0.048, p = 0.716) as acyl acceptor. In addition, to the best of our knowledge, several transesterification activities produced from microorganisms of the genus Bacillus, Brevibacillus, Lysinibacillus, Geobacillus, or Sporosarcina were reported for first time. Finally, the global lipase market was presented and segmented by date, application, geography and player highlighting the commercial contribution of microbial lipases.

Bio-Nanocarriers for Lung Cancer Management: Befriending the Barriers

Lung cancer is a complex thoracic malignancy developing consequential to aberrations in a myriad of molecular and biomolecular signaling pathways. It is one of the most lethal forms of cancers accounting to almost 1.8 million new annual incidences, bearing overall mortality to incidence ratio of 0.87. The dismal prognostic scenario at advanced stages of the disease and metastatic/resistant tumor cell populations stresses the requisite of advanced translational interdisciplinary interventions such as bionanotechnology. This review article deliberates insights and apprehensions on the recent prologue of nanobioengineering and bionanotechnology as an approach for the clinical management of lung cancer. The role of nanobioengineered (bio-nano) tools like bio-nanocarriers and nanobiodevices in secondary prophylaxis, diagnosis, therapeutics, and theranostics for lung cancer management has been discussed. Bioengineered, bioinspired, and biomimetic bio-nanotools of considerate translational value have been reviewed. Perspectives on existent oncostrategies, their critical comparison with bio-nanocarriers, and issues hampering their clinical bench side to bed transformation have also been summarized.

Azo modified hyaluronic acid based nanocapsules: CD44 targeted, UV-responsive decomposition and drug release in liver cancer cells

Herein, we demonstrate a novel UV-induced decomposable nanocapsule of natural polysaccharide (HA-azo/PDADMAC). The nanocapsules are fabricated based on layer-by-layer co-assembly of anionic azobenzene functionalized hyaluronic acid (HA-azo) and cationic poly diallyl dimethylammonium chloride (PDADMAC). When the nanocapsules are exposed to 365 nm light, ultraviolet photons can trigger the photo-isomerization of azobenzene groups in the framework. The nanocapsules could decompose from large-sized nanocapsules to small fragments. Due to their optimized original size (~180 nm), the nanocapsules can effectively avoid biological barriers, provide a long blood circulation and achieve high tumor accumulation. It can fast eliminate nanocapsules from tumor and release the loaded drugs for chemotherapy after UV-induced dissociation. Besides, HA is an endogenous polysaccharide that shows intrinsic targetability to CD44 receptors on surface of cancer cells. The intracellular experiment shows that the HA-azo/PDADMAC nanocapsules with CD44 targeting ability and UV-controlled intracellular drug release are promising for cancer chemotherapy.

Anticancer and Immunomodulatory Effects of Polysaccharides

Cancer is one of the leading causes of death and one of the most important public health problems in the world. And every year, millions of new cancers and hundreds of thousands of cancer-related deaths are reported worldwide. In recent decades, a number of biologically active polysaccharides and polysaccharide-protein complexes have been isolated from plants, lichen, algae, yeast, fungi and mushroom, and due to their antitumor and immunomodulatory properties, these compounds have received considerable attention. Overall, the two key mechanisms by which polysaccharides act on tumor cells are direct action (inhibition of cancer cell growth and induction of programmed cell death/apoptosis) and indirect action (stimulation of immunity). Immunosuppressive effects are recognizable in both cancer patients and tumor bearing animals, suggesting that the immune system plays an important role in the immune surveillance of cancer cells. Thus, enhancement of the host immune response has been evaluated as a possible way of inhibiting tumor growth without damaging the host. In addition to their therapeutic and prophylactic properties, the polysaccharides are effective and less toxic than chemotherapy. The anticancer activity and immunomodulatory effects of most polysaccharides have shown the promising and real potential for the benefits of human health.

Fabrication of tumor-targeting composites based on the triple helical β-glucan through conjugation of aptamer

Herein the nucleic acid aptamers were attached to the polydeoxyadenylic acid (poly(dA)) tail for improving the tumor-targetability and cellular internalization of s-LNT/poly(dA) composite composed of two single chains of triple helical β-glucan lentinan (s-LNT) and one poly(dA) chain. The in vitro results demonstrate that the cellular uptake of s-LNT/poly(dA) composites in MCF-7 cancer cells was enhanced effectively after attaching the aptamer. The as-prepared fluorescin isothiocyanate (FITC)-labelled LNT (LNT-FITC) through grafting was used for tracing the enhanced tumor-targetability of the composites. As a result, the cellular internalization of the LNT-FITC into MCF-7 and 4T1 cancer cells was further increased by the aptamer conjugated to poly(dA). Meanwhile, the in vivo experiments further demonstrate more s-LNT/poly(dA)-aptamer composites were effectively accumulated at the tumor site compared with s-LNT alone. This work provides a novel strategy for fabricating triplex β-glucan as delivery vectors with active tumor-targetability.

Gallic Acid-Laminarin Conjugate Is a Better Antioxidant than Sulfated or Carboxylated Laminarin

A 12.4 kDa laminarin (LM) composed of β(1→3)-glucan with β(1→6)-branches was extracted from brown seaweed Lobophora variegata and modified via carboxylation using dielectric barrier discharge (LMC), conjugation with gallic acid (LMG), and sulfation (LMS). Analyses of the chemical composition of LMC, LMG, and LMS yielded 11.7% carboxyl groups, 1.5% gallic acid, and 1.4% sulfate content, respectively. Antioxidant activities of native and modified laminarins were assessed using six different in vitro methods. Sulfation stopped the antioxidant activities of LM. On the other hand, carboxylation improved cooper chelation (1.2 times). LMG was found to be a more efficient antioxidant agent than LM in terms of copper chelation (1.3 times), reducing power (1.3 times), and total antioxidant capacity (80 times). Gallic acid conjugation was further confirmed using Fourier transform infrared spectroscopy (FT-IR) and one- and two-dimensional NMR spectroscopy analyses. LMG also did not induce cell death or affect the cell cycle of Madin–Darby canine kidney (MDCK) cells. On the contrary, LMG protected MDCK cells from H₂O₂-induced oxidative damage. Taken together, these results show that LMG has the potent antioxidant capacity, and, therefore, potential applications in pharmacological and functional food products.

Altered glycosylation in cancer: A promising target for biomarkers and therapeutics

Glycosylation is a well-regulated cell and microenvironment specific post-translational modification. Several glycosyltransferases and glycosidases orchestrate the addition of defined glycan structures on the proteins and lipids. Recent advances and systemic approaches in glycomics have significantly contributed to a better understanding of instrumental roles of glycans in health and diseases. Emerging research evidence recognized aberrantly glycosylated proteins as the modulators of the malignant phenotype of cancer cells. The Cancer Genome Atlas has identified alterations in the expressions of glycosylation-specific genes that are correlated with cancer progression. However, the mechanistic basis remains poorly explored. Recent researches have shown that specific changes in the glycan structures are associated with 'stemness' and epithelial-to-mesenchymal transition of cancer cells. Moreover, epigenetic changes in the glycosylation pattern make the tumor cells capable of escaping immunosurveillance mechanisms. The deciphering roles of glycans in cancer emphasize that glycans can serve as a source for the development of novel clinical biomarkers. The ability of glycans in intervening various stages of tumor progression and the biosynthetic pathways involved in glycan structures constitute a promising target for cancer therapy. Advances in the knowledge of innovative strategies for identifying the mechanisms of glycan-binding proteins are hoped to hold great potential in cancer therapy. This review discusses the fundamental role of glycans in regulating tumorigenesis and tumor progression and provides insights into the influence of glycans in the current tactics of targeted therapies in the clinical setting.

Carrier-free nanodrugs for safe and effective cancer treatment

Clinical applications of many anti-cancer drugs are restricted due to their hydrophobic nature, requiring use of harmful organic solvents for administration, and poor selectivity and pharmacokinetics resulting in off-target toxicity and inefficient therapies. A wide variety of carrier-based nanoparticles have been developed to tackle these issues, but such strategies often fail to encapsulate drug efficiently and require significant amounts of inorganic and/or organic nanocarriers which may cause toxicity problems in the long term. Preparation of nano-formulations for the delivery of water insoluble drugs without using carriers is thus desired, requiring elegantly designed strategies for products with high quality, stability and performance. These strategies include simple self-assembly or involving chemical modifications via coupling drugs together or conjugating them with various functional molecules such as lipids, carbohydrates and photosensitizers. During nanodrugs synthesis, insertion of redox-responsive linkers and tumor targeting ligands endows them with additional characteristics like on-target delivery, and conjugation with immunotherapeutic reagents enhances immune response alongside therapeutic efficacy. This review aims to summarize the methods of making carrier-free nanodrugs from hydrophobic drug molecules, evaluating their performance, and discussing the advantages, challenges, and future development of these strategies.

Dexamethasone- loaded polymeric porous sponge as a direct pulp capping agent

This study aims to achieve the principles of tissue engineering using biopolymers to be applied in the field of vital endodontic treatment to stimulate stem cells and engineering and regeneration of dentin tissue. the polymer blend was loaded with the steroidal anti-inflammatory drug, dexamethasone, and the porous drug-loaded bio-sponge was produced by lyophilization. Bio-sponge, as a direct pulp capping agent, was histologically studied compared to calcium hydroxide Ca(OH)₂ in an animal experiment. The results indicated the effectiveness of the bio-sponge as a direct pulp capping agent where the dentin bridge was formed faster than Ca(OH)₂ treated samples. There was no inflammatory response in the pulp tissue throughout the follow-up period. The porous bio-sponge loaded with dexamethasone with a neutral pH resulted in enhancement of the odontoblast differentiation from stem cells, resulting in the formation of a renewed dentin bridge without the slightest inflammatory response in the pulp.

Nanotechnology-Based Biopolymeric Oral Delivery Platforms for Advanced Cancer Treatment

Routes of drug administration and their corresponding physiochemical characteristics play major roles in drug therapeutic efficiency and biological effects. Each route of delivery has favourable aspects and limitations. The oral route of delivery is the most convenient, widely accepted and safe route. However, the oral route of chemotherapeutics to date have displayed high gastric degradation, low aqueous solubility, poor formulation stability and minimum intestinal absorption. Thus, mainstream anti-cancer drugs in current formulations are not suitable as oral chemotherapeutic formulations. The use of biopolymers such as chitosan, gelatin, hyaluronic acid and polyglutamic acid, for the synthesis of oral delivery platforms, have potential to help overcome problems associated with oral delivery of chemotherapeutics. Biopolymers have favourable stimuli-responsive properties, and thus can be used to improve oral bioavailability of anti-cancer drugs. These biopolymeric formulations can protect gastric-sensitive drugs from pH degradation, target specific binding sites for targeted absorption and consequently control drug release. In this review, the use of various biopolymers as oral drug delivery systems for chemotherapeutics will be discussed.

Strategies for Delivery of siRNAs to Ovarian Cancer Cells

The unmet need for novel therapeutic options for ovarian cancer (OC) deserves further investigation. Among the different novel drugs, small interfering RNAs (siRNAs) are particularly attractive because of their specificity of action and efficacy, as documented in many experimental setups. However, the fragility of these molecules in the biological environment necessitates the use of delivery materials able to protect them and possibly target them to the cancer cells. Among the different delivery materials, those based on polymers and lipids are considered very interesting because of their biocompatibility and ability to carry/deliver siRNAs. Despite these features, polymers and lipids need to be engineered to optimize their delivery properties for OC. In this review, we concentrated on the description of the therapeutic potential of siRNAs and polymer-/lipid-based delivery systems for OC. After a brief description of OC and siRNA features, we summarized the strategies employed to minimize siRNA delivery problems, the targeting strategies to OC, and the preclinical models available. Finally, we discussed the most interesting works published in the last three years about polymer-/lipid-based materials for siRNA delivery.

Chemopreventive role of arabinogalactan against experimentally induced pulmonary carcinogenesis: a study in relation to its initiation phase

The aim of the present study is to divulge the chemopreventive potential of arabinogalactan (AG) on benzo(a)pyrene [B(a)P] induced initiation of lung carcinogenesis. AG is one of the naturally occurring bioactive polysaccharides which is widely found in medicinal plants. Male Balb/c mice were divided into four experimental groups. Group I served as control. Group II animals were injected with B(a)P (50 mg/kg b. wt. i.p.). Group III animals were administered with AG (7.5 mg/kg b.wt.) orally. Group IV animals received B(a)P and AG as in group II and group III, respectively. B(a)P treatment in mice resulted in imbalance of carcinogen metabolizing enzymes and respiratory marker enzymes at 2nd, 6th and 10th week of the experimental protocol. Also, it leads to the increased protein synthesis as depicted by increased argyrophilic nucleolar organizer regions (AgNOR) positive cells and altered histopathological features. Studies on bronchoalveolar lavage fluid (balf) of B(a)P exposed animals revealed increase in surface tension when compared with control counterparts. Apart from target tissue (lung), B(a)P also led to the clastogenic damage in other tissues (spleen and bone marrow) as depicted by increase in percentage of micronucleus cells at different time intervals. Treatment with AG efficiently counteracted all the above anomalies and restored cellular homeostasis. These observations suggest that AG has the potential to modulate B(a)P induced changes in the pulmonary tissue as well as other tissues which could have implications in delaying the initiation of carcinogenesis, however, further investigations are required to explore its complete mechanism of action.

Developments in Carbohydrate-Based Cancer Therapeutics

Cancer cells of diverse origins express extracellular tumor-specific carbohydrate antigens (TACAs) because of aberrant glycosylation. Overexpressed TACAs on the surface of tumor cells are considered biomarkers for cancer detection and have always been prioritized for the development of novel carbohydrate-based anti-cancer vaccines. In recent years, progress has been made in developing synthetic, carbohydrate-based antitumor vaccines to improve immune responses associated with targeting these specific antigens. Tumor cells also exhaust more energy for proliferation than normal cells, by consuming excessive amounts of glucose via overexpressed sugar binding or transporting receptors located in the cellular membrane. Furthermore, inspired by the Warburg effect, glycoconjugation strategies of anticancer drugs have gained considerable attention from the scientific community. This review highlights a small cohort of recent efforts which have been made in carbohydrate-based cancer treatments, including vaccine design and the development of glycoconjugate prodrugs, glycosidase inhibiting iminosugars, and early cancer diagnosis.

Theoretical Importance of PVP-Alginate Hydrogels Structure on Drug Release Kinetics

BACKGROUND

The new concepts of personalized and precision medicine require the design of more and more refined delivery systems. In this frame, hydrogels can play a very important role as they represent the best surrogate of soft living tissues for what concerns rheological properties. Thus, this paper focusses on a global theoretical approach able to describe how hydrogel polymeric networks can affect the release kinetics of drugs characterized by different sizes. The attention is focused on a case study dealing with an interpenetrated hydrogel made up by alginate and poly(N-vinyl-2-pyrrolidone).

METHODS

Information about polymeric network characteristics (mesh size distribution and polymer volume fraction) is deduced from the theoretical interpretation of the rheological and the low field Nuclear Magnetic Resonance (NMR) characterization of hydrogels. This information is then, embodied in the mass balance equation whose resolution provides the release kinetics.

RESULTS

Our simulations indicate the influence of network characteristics on release kinetics. In addition, the reliability of the proposed approach is supported by the comparison of the model outcome with experimental release data.

CONCLUSIONS

This study underlines the necessity of a global theoretical approach in order to design reliable delivery systems based on hydrogels.

Characterization and study of the antibacterial mechanisms of silver nanoparticles prepared with microalgal exopolysaccharides

The green synthesis of biomaterials is of significant interest as it enables the safe and sustainable preparation of noble metallic nanoparticles for medical applications. Microalgae polysaccharides have received attention due to their outstanding properties such as biocompatibility, biodegradability and low cost. In addition, due to their variety of remarkable biological and physicochemical properties, polysaccharide-based nanoparticles have advantageous features yet to be explored. The primary objective of the current research was to investigate exopolysaccharides isolated from green microalgae Botryococcus braunii (EPBb) and Chlorella pyrenoidosa (EPCp), as both reducing and stabilizing agents, for the green synthesis of silver nanoparticles (AgNPs). Their antibacterial activity towards Gram-positive bacteria (Staphylococcus aureus), Gram-negative bacteria (Escherichia coli), and antibiotic-resistant bacteria (methicillin-resistant Staphylococcus aureus) was studied, as well as their cytotoxicity to human dermal fibroblasts. The presently synthesized AgNPs were spherical in shape and exhibited characteristic surface plasmon resonance at 430 nm. The main population had a particle size which ranged between 5 and 15 nm as analyzed by transmission electron micrographs. Zeta potentials averaged -51.81 ± 3.01 mV using EPBb and -12.16 ± 2.41 mV using EPCp. More importantly, AgNPs possessed strong antibacterial activity in a dose-dependent manner, even against drug-resistant bacteria. The enhanced antibacterial activity of these particles is explained due to extensive reactive oxygen species generation and bacterial cell membrane damage. In contrast, such AgNPs were not cytotoxic at the same therapeutic range to fibroblasts (0.5-10.0 μg/mL). In summary, these results showed that polysaccharide-capped AgNPs have a strong potential for numerous medical applications, such as antibacterial agents in pharmaceutical and biomedical areas.

Molecular simulation and in vitro evaluation of chitosan nanoparticles as drug delivery systems for the controlled release of anticancer drug cytarabine against solid tumours

The present work is an attempt to integrate the molecular simulation studies with in vitro cytotoxicity of cytarabine-loaded chitosan nanoparticles and exploring the potential of this formulation as therapeutics for treating solid tumours. The molecular simulation was performed using GROMACS v5.4 in which, chitosan polymer (CHT; six molecules) was used to study the encapsulation and release of a single molecule of cytarabine. Root Mean Square Deviation (RMSD) of the Cα atom of cytarabine (CBR) molecule shows that CBR starts to diffuse out of the CHT polymer binding pocket around 10.2 ns, indicated by increased fluctuation of RMSD at pH 6.4, while the drug diffusion is delayed at pH 7.4 and starts diffusing around 17.5 ns. Cytarabine-loaded chitosan nanoparticles (CCNP), prepared by ionic gelation method were characterized for encapsulation efficiency, particle size and morphology, zeta potential, crystallinity and drug release profile at pH 6.4 and 7.4. CCNPs showed 64% encapsulation efficiency with an average diameter of 100 nm and zeta potential of + 53.9 mV. It was found that cytarabine existed in amorphous state in nanoformulation. In vitro release studies showed 70% cytarabine was released from the chitosan-based nanoformulation release at pH 6.4, which coincides with the pH of tumour microenvironment. Cytotoxicity against breast cancer cell line (MCF 7) was higher for nanoformulation compared to free cytarabine. Haemocompatibility studies showed that chitosan-based nanoformulation is safe, biocompatible and nonhaemolytic in nature; hence, can be used as a safe drug delivery system. Taken together, our study suggests that chitosan nanoformulation would be an effective strategy for the pH-dependent release of cytarabine against solid tumours and might impart better therapeutic efficiency.