Poly‐allylamine hydrochloride and fucoidan‐based self‐assembled polyelectrolyte complex nanoparticles for cancer therapeutics

Sustainable oil palm trunk fibre based activated carbon for the adsorption of methylene blue

Activated carbon (AC) is becoming the limelight due to its widespread application as an adsorbent for wastewater treatment, gases, and catalysis. However, its high consumption and price have drawn more attention to the sustainable use of natural resources as precursor for AC production. This study focuses on synthesising AC from two types of oil palm trunk (OPT) fibres, a significant agricultural waste products produced by Malaysia's thriving palm oil industries. The BET surface area of about 2057.9 m2 g-1 was achieved by chemical activation with phosphoric acid (H3PO4). The efficiency of the synthesised AC was critically analysed based on the adsorption experiments with methylene blue (MB) by varying several parameters (dosage of adsorbent, pH, initial dye concentration, and temperature of the solution) to elucidate the adsorption mechanism(s). A maximum adsorption capacity of 320.4 mg g-1 at 50 °C was achieved, and the Temkin (r2 = 0.98, 0.95, 0.95) and Langmuir (r2 = 0.94, 0.93, 0.95) isotherm models fitted the adsorption process better than the Freundlich (r2 = 0.95, 0.90, 0.86) model. Besides, the pseudo-second-order model (r2 > 0.90) best described the adsorption process, favouring chemisorption over physisorption. Thermodynamics showed MB adsorption on AC was spontaneous except at the highest dye concentration. It was exothermic at lower dye concentrations (50 and 100 mg L-1) and endothermic at higher ones (300, 500, and 700 mg L-1). In a nutshell, this study reveals that OPT fibre is a promising precursor for synthesising highly porous AC for the adsorption of MB dye.

Bioactive Carbohydrate Polymers-Between Myth and Reality

Polysaccharides are complex macromolecules long regarded as energetic storage resources or as components of plant and fungal cell walls. They have also been described as plant mucilages or microbial exopolysaccharides. The development of glycosciences has led to a partial and difficult deciphering of their other biological functions in living organisms. The objectives of glycobiochemistry and glycobiology are currently to correlate some structural features of polysaccharides with some biological responses in the producing organisms or in another one. In this context, the literature focusing on bioactive polysaccharides has increased exponentially during the last two decades, being sometimes very optimistic for some new applications of bioactive polysaccharides, notably in the medical field. Therefore, this review aims to examine bioactive polysaccharide, taking a critical look of the different biological activities reported by authors and the reality of the market. It focuses also on the chemical, biochemical, enzymatic, and physical modifications of these biopolymers to optimize their potential as bioactive agents.

Surface Decoration via Physical Interaction of Cupric Diethyldithiocarbamate Nanocrystals and Its Impact on Biodistribution and Tumor Targeting

The vascular wall is the first physiologic barrier that circulating nanoparticles (NPs) encounter, which also is a key biological barrier to cancer drug delivery. NPs can continually scavenge the endothelium for biomarkers of cancer, and the chance of NPs' extravasation into the tumors can be enhanced. Here, we envision P-selectin as a target for specific delivery of drug nanocrystals to tumors. The cupric diethyldithiocarbamate nanocrystals (CuET NCs) were first prepared by an antisolvent method, and then nanocrystals were coated with fucoidan via physical interaction. The fucoidan-coated CuET nanocrystals (CuET@Fuc) possess high drug loading and have the ability to interact with human umbilical vein endothelial cells expressing P-selectin, which transiently enhances the endothelial permeability and facilitates CuET@Fuc extravasation from the peritumoral vascular to achieve higher tumor accumulation of drugs than bare CuET NCs. The CuET NC shows poorer anticancer efficacy than CuET@Fuc at the same dose of CuET. Upon repeated dosing of CuET@Fuc for 2 weeks, no mortality was observed in treated melanoma-bearing mice, while the mortality in the control group and excipient-treated groups reached 23%. The growth rate of melanoma in the CuET@Fuc-treated group was significantly lower than those in other groups. Furthermore, an acute toxicity study revealed that CuET@Fuc is a safe formulation for cancer treatment.

Enhanced Cellular Uptake in an Electrostatically Interacting Fucoidan-L-Arginine Fiber Complex

Fucoidan is an abundant marine sulfated polysaccharide extracted from the cell wall of brown macroalgae (seaweed). Recently, fucoidan has been highly involved in various industrial applications, such as pharmaceuticals, biomedicals, cosmetics, and food. However, the presence of a sulfate group (negative surface charge) in the fucoidan structure limits its potential and biological activity for use in biomedical applications during cellular uptake. Thus, we aimed to improve the uptake of fucoidan by using an L-arginine uptake enhancer within an in vitro study. A Fucoidan-L-Arginine (Fuc-L-Arg) fiber complex was prepared via α-helical electrostatic interactions using a freeze-drying technique and confirmed using field-emission scanning electron microscopy, Fourier transform infrared spectroscopy, and nuclear magnetic resonance spectroscopy. In addition, fucoidan was conjugated with cyanine 3 (Cy3) dye to track its cellular uptake. Furthermore, the results of Fuc-L-Arg (1:1, 1:2.5) complexes revealed biocompatibility >80% at various concentrations (5, 10, 25, 50, 100 µg/mL). Owing to the higher internalization of the Fuc-L-Arg (1:5) complex, it exhibited <80% biocompatibility at higher concentrations (25, 50, 100 µg/mL) of the complex. In addition, improved cellular internalization of Fuc-L-Arg complexes (1:5) in HeLa cells have been proved via flow cytometry quantitative analysis. Hence, we highlight that the Fuc-L-Arg (1:5) fiber complex can act as an excellent biocomplex to exhibit potential bioactivities, such as targeting cancers, as fucoidan shows higher permeability in HeLa cells.

Anti-tumour drugs of marine origin currently at various stages of clinical trials (review)

Oncological diseases for a long time have remained one of the most significant health problems of modern society, which causes great losses in its labour and vital potential. Contemporary oncology still faces unsolved issues as insufficient efficacy of treatment of progressing and metastatic cancer, chemoresistance, and side-effects of the traditional therapy which lead to disabilities among or death of a high number of patients. Development of new anti-tumour preparations with a broad range of pharmaceutical properties and low toxicity is becoming increasingly relevant every year. The objective of the study was to provide a review of the recent data about anti-tumour preparations of marine origin currently being at various phases of clinical trials in order to present the biological value of marine organisms – producers of cytotoxic compounds, and the perspectives of their use in modern biomedical technologies. Unlike the synthetic oncological preparations, natural compounds are safer, have broader range of cytotoxic activity, can inhibit the processes of tumour development and metastasis, and at the same time have effects on several etiopathogenic links of carcinogenesis. Currently, practical oncology uses 12 anti-tumour preparations of marine origin (Fludarabine, Cytarabine, Midostaurin, Nelarabine, Eribulin mesylate, Brentuximab vedotin, Trabectedin, Plitidepsin, Enfortumab vedotin, Polatuzumab vedotin, Belantamab mafodotin, Lurbinectedin), 27 substances are at different stages of clinical trials. Contemporary approaches to the treatment of oncological diseases are based on targeted methods such as immune and genetic therapies, antibody-drug conjugates, nanoparticles of biopolymers, and metals. All those methods employ bioactive compounds of marine origin. Numerous literature data from recent years indicate heightened attention to the marine pharmacology and the high potential of marine organisms for the biomedicinal and pharmaceutic industries.

Growth characteristics of human bone marrow mesenchymal stromal cells at cultivation on synthetic polyelectrolyte nanofilms in vitro

This study examines the adhesive properties and cytotoxicity of polyelectrolyte nanofilms from polyethyleneimine (PEI), polyallylamine hydrochloride (PAH) and sodium polystyrene sulfonate (PSS) on human bone marrow mesenchymal stromal cells (h-MSCs) and mouse adipose tissue (m-MSC) in vitro. Films are formed on 24- and 96-well culture plates in the combinations: PEI, PAH, PEI-PSS, PEI-PSS-PAH, PEI-PSS-PEI. An analysis of the culture results show that direct contact of h-MSCs with the PEI surface promotes adhesion (93–95% of adhesive cells versus 40% in the control). On the PEI surface, h-MSCs are evenly distributed, form colonies and 80% monolayer after 72 h of culture, as in the control on culture plastic. On nanofilms from PAH and PEI-PSS-PAH, cells grow in the form of rosette-like colonies with long and thin processes similar to neurites. The cytotoxic properties of PSS were revealed in direct contact with h-MSCs (more than 40% of nonviable cells with damaged plasma membranes). On the PSS surface, cells lost their adhesiveness. To culture and stably grow the cell mass of h-MSCs, it is better to use monolayer nanofilms made of highly adhesive and non-toxic PEI polyelectrolyte, which can bind the growth factors of blood serum and platelet lysate, ensuring the growth of h-MSCs under in vitro deprivation conditions.

Review of Contemporary Self-Assembled Systems for the Controlled Delivery of Therapeutics in Medicine

The novel and unique design of self-assembled micro and nanostructures can be tailored and controlled through the deep understanding of the self-assembly behavior of amphiphilic molecules. The most commonly known amphiphilic molecules are surfactants, phospholipids, and block copolymers. These molecules present a dual attraction in aqueous solutions that lead to the formation of structures like micelles, hydrogels, and liposomes. These structures can respond to external stimuli and can be further modified making them ideal for specific, targeted medical needs and localized drug delivery treatments. Biodegradability, biocompatibility, drug protection, drug bioavailability, and improved patient compliance are among the most important benefits of these self-assembled structures for drug delivery purposes. Furthermore, there are numerous FDA-approved biomaterials with self-assembling properties that can help shorten the approval pathway of efficient platforms, allowing them to reach the therapeutic market faster. This review focuses on providing a thorough description of the current use of self-assembled micelles, hydrogels, and vesicles (polymersomes/liposomes) for the extended and controlled release of therapeutics, with relevant medical applications. FDA-approved polymers, as well as clinically and commercially available nanoplatforms, are described throughout the paper.

Evaluation of a Brown Seaweed Extract from Dictyosiphon foeniculaceus as a Potential Therapeutic Agent for the Treatment of Glioblastoma and Uveal Melanoma

Ingredients of brown seaweed like fucoidans are often described for their beneficial biological effects, that might be interesting for a medical application. In this study, we tested an extract from Dictyosiphon foeniculaceus (DF) to evaluate the effects in glioblastoma and uveal melanoma, looking for a possible anti-cancer treatment. We investigated toxicity, VEGF (vascular endothelial growth factor) secretion and gene expression of tumor and non-tumor cells. SVGA (human fetal astrocytes), the human RPE (retinal pigment epithelium) cell line ARPE-19, the tumor cell line OMM-1 (human uveal melanoma), and two different human primary glioblastoma cultures (116-14 and 118-14) were used. Tests for cell viability were conducted with MTS-Assay (3-(4,5-Dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium), and the proliferation rate was determined with cell counting. VEGF secretion was assessed with ELISA (enzyme-linked immunosorbent assay). The gene expression of VEGF receptor 1 (VEGFR1), VEGF receptor 2 (VEGFR2) and VEGF-A was determined with real-time qPCR (quantitative polymerase chain reaction). DF lowered the cell viability of OMM-1. Proliferation rates of ARPE-19 and OMM-1 were decreased. The VEGF secretion was inhibited in ARPE-19 and OMM-1, whereas it was increased in SVGA and 116-14. The expression of VEGFR1 was absent and not influenced in OMM-1 and ARPE-19. VEGFR2 expression was lowered in 116-14 after 24 h, whereas VEGF-A was increased in 118-14 after 72 h. The extract lowered cell viability slightly and was anti-proliferative depending on the cell type investigated. VEGF was heterogeneously affected. The results in glioblastoma were not promising, but the anti-tumor properties in OMM-1 could make them interesting for further research concerning cancer diseases in the human eye.

Pancreatic Cancer (PDAC): Introduction of Evidence-Based Complementary Measures into Integrative Clinical Management

The most common form of pancreatic cancer is pancreatic ductal adenocarcinoma (PDAC), which comprises some 85% of all cases. Currently, this is the fourth highest cause of cancer mortality worldwide and its incidence is rising steeply. Commonly applied clinical therapies offer limited chance of a lasting cure and the five-year survival rate is one of the lowest of the commonly occurring cancers. This review cultivates the hypothesis that the best management of PDAC would be possible by integrating 'western' clinical medicine with evidence-based complementary measures. Protecting the liver, where PDAC frequently first spreads, is also given some consideration. Overall, the complementary measures are divided into three groups: dietary factors, nutraceutical agents and lifestyle. In turn, dietary factors are considered as general conditioners, multi-factorial foodstuffs and specific compounds. The general conditioners are alkalinity, low-glycemic index and low-cholesterol. The multi-factorial foodstuffs comprise red meat, fish, fruit/vegetables, dairy, honey and coffee. The available evidence for the beneficial effects of the specific dietary and nutraceutical agents was considered at four levels (in order of prominence): clinical trials, meta-analyses, in vivo tests and in vitro studies. Thus, 9 specific agents were identified (6 dietary and 3 nutraceutical) as acceptable for integration with gemcitabine chemotherapy, the first-line treatment for pancreatic cancer. The specific dietary agents were the following: Vitamins A, C, D and E, genistein and curcumin. As nutraceutical compounds, propolis, triptolide and cannabidiol were accepted. The 9 complementary agents were sub-grouped into two with reference to the main 'hallmarks of cancer'. Lifestyle factors covered obesity, diabetes, smoking, alcohol and exercise. An integrative treatment regimen was devised for the management of PDAC patients. This involved combining first-line gemcitabine chemotherapy with the two sub-groups of complementary agents alternately in weekly cycles. The review concludes that integrated management currently offers the best patient outcome. Opportunities to be investigated in the future include emerging modalities, precision medicine, the nerve input to tumors and, importantly, clinical trials.

Therapies from Fucoidan: New Developments

Since our last review in 2015, the study and use of fucoidan has extended in several research areas. Clinical use of fucoidan for the treatment of renal disease has become available and human safety studies have been undertaken on radiolabeled fucoidan for the purpose of imaging thrombi. Fucoidan has been incorporated into an increasing number of commercially available supplements and topical treatments. In addition, new measuring techniques are now available to assess the biologically relevant uptake of fucoidans and to assist in production. Microbiome modulation and anti-pathogenic effects are increasingly promising applications for fucoidans, due to the need for alternative approaches to antibiotic use in the food chain. This review outlines promising new developments in fucoidan research, including potential future therapeutic use.

Possibilities of Fucoidan Utilization in the Development of Pharmaceutical Dosage Forms

Fucoidan is a polysaccharide built from L-fucose molecules. The main source of this polysaccharide is the extracellular matrix of brown seaweed (Phaeophyta), but it can be also isolated from invertebrates such as sea urchins (Echinoidea) and sea cucumbers (Holothuroidea). Interest in fucoidan is related to its broad biological activity, including possible antioxidant, anti-inflammatory, antifungal, antiviral or antithrombotic effects. The potential application of fucoidan in the pharmaceutical technology is also due to its ionic nature. The negative charge of the molecule results from the presence of sulfate residues in the C-2 and C-4 positions, occasionally in C-3, allowing the formation of complexes with other oppositely charged molecules. Fucoidan is non-toxic, biodegradable and biocompatible compound approved by Food and Drug Administration (FDA) as Generally Recognized As Safe (GRAS) category as food ingredient. Fucoidan plays an important role in the pharmaceutical technology, so in this work aspects concerning its pharmaceutical characteristics and designing of various dosage forms (nanoparticles, liposomes, microparticles, and semisolid formulations) with fucoidan itself and with its combinations with other polymers or components that give a positive charge were reviewed. Advantages and limitations of fucoidan utilization in the pharmaceutical technology were also discussed.