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Mar. Drugs, Volume 12, Issue 12 (December 2014), Pages 5719-6268

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Open AccessArticle Mucoadhesive Microparticles for Gastroretentive Delivery: Preparation, Biodistribution and Targeting Evaluation
Mar. Drugs 2014, 12(12), 5764-5787; doi:10.3390/md12125764
Received: 16 October 2014 / Revised: 14 November 2014 / Accepted: 19 November 2014 / Published: 1 December 2014
Cited by 4 | PDF Full-text (931 KB) | HTML Full-text | XML Full-text
Abstract
The aim of this research was to prepare and characterize alginate-chitosan mucoadhesive microparticles containing puerarin. The microparticles were prepared by an emulsification-internal gelatin method using a combination of chitosan and Ca2+ as cationic components and alginate as anions. Surface morphology, particle size,
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The aim of this research was to prepare and characterize alginate-chitosan mucoadhesive microparticles containing puerarin. The microparticles were prepared by an emulsification-internal gelatin method using a combination of chitosan and Ca2+ as cationic components and alginate as anions. Surface morphology, particle size, drug loading, encapsulation efficiency and swelling ratio, in vitro drug released, in vitro evaluation of mucoadhesiveness and Fluorescence imaging of the gastrointestinal tract were determined. After optimization of the formulation, the encapsulation efficiency was dramatically increased from 70.3% to 99.2%, and a highly swelling ratio was achieved with a change in particle size from 50.3 ± 11.2 μm to 124.7 ± 25.6 μm. In ethanol induced gastric ulcers, administration of puerarin mucoadhesive microparticles at doses of 150 mg/kg, 300 mg/kg, 450 mg/kg and 600 mg/kg body weight prior to ethanol ingestion significantly protected the stomach ulceration. Consequently, significant changes were observed in inflammatory cytokines, such as prostaglandin E2 (PGE2), tumor necrosis factor (TNF-α), interleukin 6 (IL-6), and interleukin1β (IL-1β), in stomach tissues compared with the ethanol control group. In conclusion, core-shell type pH-sensitive mucoadhesive microparticles loaded with puerarin could enhance puerarin bioavailability and have the potential to alleviate ethanol-mediated gastric ulcers. Full article
(This article belongs to the Special Issue Advances in Marine Chitin and Chitosan) Printed Edition available
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Open AccessCommunication Two New Lyngbyatoxin Derivatives from the Cyanobacterium, Moorea producens
Mar. Drugs 2014, 12(12), 5788-5800; doi:10.3390/md12125788
Received: 10 October 2014 / Revised: 11 November 2014 / Accepted: 19 November 2014 / Published: 1 December 2014
Cited by 5 | PDF Full-text (595 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
The toxin-producing cyanobacterium, Moorea producens, is a known causative organism of food poisoning and seaweed dermatitis (also known as “swimmer’s itch”). Two new toxic compounds were isolated and structurally elucidated from an ethyl acetate extract of M. producens collected from Hawaii. Analyses
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The toxin-producing cyanobacterium, Moorea producens, is a known causative organism of food poisoning and seaweed dermatitis (also known as “swimmer’s itch”). Two new toxic compounds were isolated and structurally elucidated from an ethyl acetate extract of M. producens collected from Hawaii. Analyses of HR-ESI-MS and NMR spectroscopies, as well as optical rotations and CD spectra indicated two new lyngbyatoxin derivatives, 2-oxo-3(R)-hydroxy-lyngbyatoxin A (1) and 2-oxo-3(R)-hydroxy-13-N-desmethyl-lyngbyatoxin A (2). The cytotoxicity and lethal activities of 1 and 2 were approximately 10- to 150-times less potent than lyngbyatoxin A. Additionally, the binding activities of 1 and 2 possessed 10,000-times lower affinity for the protein kinase Cδ (PKCδ)-C1B peptide when compared to lyngbyatoxin A. These findings suggest that these new lyngbyatoxin derivatives may mediate their acute toxicities through a non-PKC activation pathway. Full article
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Open AccessArticle The Influence of 1-Butanol and Trisodium Citrate Ion on Morphology and Chemical Properties of Chitosan-Based Microcapsules during Rigidification by Alkali Treatment
Mar. Drugs 2014, 12(12), 5801-5816; doi:10.3390/md12125801
Received: 9 October 2014 / Revised: 17 November 2014 / Accepted: 19 November 2014 / Published: 2 December 2014
Cited by 4 | PDF Full-text (1360 KB) | HTML Full-text | XML Full-text
Abstract
Linseed oil which has various biomedical applications was encapsulated by chitosan (Chi)-based microcapsules in the development of a suitable carrier. Oil droplets formed in oil-in-water emulsion using sodium dodecyl sulfate (SDS) as emulsifier was stabilized by Chi, and microcapsules with multilayers were formed
[...] Read more.
Linseed oil which has various biomedical applications was encapsulated by chitosan (Chi)-based microcapsules in the development of a suitable carrier. Oil droplets formed in oil-in-water emulsion using sodium dodecyl sulfate (SDS) as emulsifier was stabilized by Chi, and microcapsules with multilayers were formed by alternate additions of SDS and Chi solutions in an emulsion through electrostatic interaction. No chemical cross-linker was used in the study and the multilayer shell membrane was formed by ionic gelation using Chi and SDS. The rigidification of the shell membrane of microcapsules was achieved by alkali treatment in the presence of a small amount of 1-butanol to reduce aggregation. A trisodium citrate solution was used to stabilize the charge of microcapsules by ionic cross-linking. Effects of butanol during alkali treatment and citrate in post alkali treatment were monitored in terms of morphology and the chemical properties of microcapsules. Various characterization techniques revealed that the aggregation was decreased and surface roughness was increased with layer formation. Full article
(This article belongs to the Special Issue Advances in Marine Chitin and Chitosan) Printed Edition available
Open AccessArticle Chromomycin A2 Induces Autophagy in Melanoma Cells
Mar. Drugs 2014, 12(12), 5839-5855; doi:10.3390/md12125839
Received: 22 August 2014 / Revised: 17 November 2014 / Accepted: 20 November 2014 / Published: 4 December 2014
Cited by 4 | PDF Full-text (1041 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
The present study highlights the biological effects of chromomycin A2 toward metastatic melanoma cells in culture. Besides chromomycin A2, chromomycin A3 and demethylchromomycin A2 were also identified from the extract derived from Streptomyces sp., recovered from Paracuru Beach, located in the northeast region
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The present study highlights the biological effects of chromomycin A2 toward metastatic melanoma cells in culture. Besides chromomycin A2, chromomycin A3 and demethylchromomycin A2 were also identified from the extract derived from Streptomyces sp., recovered from Paracuru Beach, located in the northeast region of Brazil. The cytotoxic activity of chromomycin A2 was evaluated across a panel of human tumor cell lines, which found IC50 values in the nM-range for exposures of 48 and 72 h. MALME-3M, a metastatic melanoma cell line, showed the highest sensitivity to chromomycin A2 after 48h incubation, and was chosen as a model to investigate this potent cytotoxic effect. Treatment with chromomycin A2 at 30 nM reduced cell proliferation, but had no significant effect upon cell viability. Additionally, chromomycin A2 induced accumulation of cells in G0/G1 phase of the cell cycle, with consequent reduction of S and G2/M and unbalanced expression of cyclins. Chromomycin A2 treated cells depicted several cellular fragments resembling autophagosomes and increased expression of proteins LC3-A and LC3-B. Moreover, exposure to chromomycin A2 also induced the appearance of acidic vacuolar organelles in treated cells. These features combined are suggestive of the induction of autophagy promoted by chromomycin A2, a feature not previously described for chromomycins. Full article
(This article belongs to the Special Issue Bioactive Compounds from Marine Microbes)
Open AccessCommunication Rumphellaoic Acid A, a Novel Sesquiterpenoid from the Formosan Gorgonian Coral Rumphella antipathies
Mar. Drugs 2014, 12(12), 5856-5863; doi:10.3390/md12125856
Received: 9 September 2014 / Revised: 4 November 2014 / Accepted: 21 November 2014 / Published: 4 December 2014
Cited by 6 | PDF Full-text (410 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
A novel sesquiterpenoid, rumphellaoic acid A (1), was isolated from the gorgonian coral Rumphella antipathies, and was found to possess a carbon skeleton that was obtained for the first time from a natural sources. The structure of 1 was elucidated
[...] Read more.
A novel sesquiterpenoid, rumphellaoic acid A (1), was isolated from the gorgonian coral Rumphella antipathies, and was found to possess a carbon skeleton that was obtained for the first time from a natural sources. The structure of 1 was elucidated by spectroscopic methods and this compound and was found to exert a moderate inhibitory effect on the release of elastase by human neutrophils. Full article
(This article belongs to the Special Issue Terpenoids of Marine Origin)
Open AccessArticle Polyoxygenated Steroids from the Octocoral Leptogorgia punicea and in Vitro Evaluation of Their Cytotoxic Activity
Mar. Drugs 2014, 12(12), 5864-5880; doi:10.3390/md12125864
Received: 20 August 2014 / Revised: 19 November 2014 / Accepted: 20 November 2014 / Published: 4 December 2014
Cited by 2 | PDF Full-text (603 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
Five new polyoxygenated marine steroids—punicinols A–E (15)—were isolated from the gorgonian Leptogorgia punicea and characterized by spectroscopic methods (IR, MS, 1H, 13C and 2-D NMR). The five compounds induced in vitro cytotoxic effects against lung cancer A549
[...] Read more.
Five new polyoxygenated marine steroids—punicinols A–E (15)—were isolated from the gorgonian Leptogorgia punicea and characterized by spectroscopic methods (IR, MS, 1H, 13C and 2-D NMR). The five compounds induced in vitro cytotoxic effects against lung cancer A549 cells, while punicinols A and B were the most active, with IC50 values of 9.7 μM and 9.6 μM, respectively. The synergistic effects of these compounds with paclitaxel, as well as their effects on cell cycle distribution and their performance in the clonogenic assay, were also evaluated. Both compounds demonstrated significant synergistic effects with paclitaxel. Full article
Open AccessArticle Cytotoxic Polyketides from the Deep-Sea-Derived Fungus Engyodontium album DFFSCS021
Mar. Drugs 2014, 12(12), 5902-5915; doi:10.3390/md12125902
Received: 20 October 2014 / Revised: 25 November 2014 / Accepted: 25 November 2014 / Published: 9 December 2014
Cited by 14 | PDF Full-text (642 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
Eight new chromones, engyodontiumones A–H (18), and three new phenol derivatives (911) together with eight known polyketides (1219) were isolated from the deep-sea-derived fungus Engyodontium album DFFSCS021. Their structures were identified
[...] Read more.
Eight new chromones, engyodontiumones A–H (18), and three new phenol derivatives (911) together with eight known polyketides (1219) were isolated from the deep-sea-derived fungus Engyodontium album DFFSCS021. Their structures were identified by extensive spectroscopic analysis. Compounds 8 and 16 showed significant selective cytotoxicity against human histiocytic lymphoma U937 cell line with IC50 values of 4.9 and 8.8 μM, respectively. In addition, this is the first time to report that 8, 15 and 16 had mild antibacterial activity against Escherichia coli and Bacillus subtilis, and 15 showed potent antilarval activity against barnacle Balanus amphitrite larval settlement. Full article
Open AccessArticle Sargassopenillines A–G, 6,6-Spiroketals from the Alga-Derived Fungi Penicillium thomii and Penicillium lividum
Mar. Drugs 2014, 12(12), 5930-5943; doi:10.3390/md12125930
Received: 24 September 2014 / Revised: 21 November 2014 / Accepted: 2 December 2014 / Published: 9 December 2014
Cited by 6 | PDF Full-text (640 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
Seven new 6,6-spiroketals, sargassopenillines A–G (17) were isolated from the alga-derived fungi Penicillium thomii KMM 4645 and Penicillium lividum KMM 4663. The structures of these metabolites were determined by HR-MS and 1D and 2D NMR. The absolute configurations of
[...] Read more.
Seven new 6,6-spiroketals, sargassopenillines A–G (17) were isolated from the alga-derived fungi Penicillium thomii KMM 4645 and Penicillium lividum KMM 4663. The structures of these metabolites were determined by HR-MS and 1D and 2D NMR. The absolute configurations of compounds 1, 5 and 6 were assigned by the modified Mosher’s method and by CD data. Sargassopenilline C (3) inhibited the transcriptional activity of the oncogenic nuclear factor AP-1 with an IC50 value of 15 µM. Full article
Open AccessArticle Atlantic Salmon (Salmo salar L.) as a Marine Functional Source of Gamma-Tocopherol
Mar. Drugs 2014, 12(12), 5944-5959; doi:10.3390/md12125944
Received: 16 September 2014 / Revised: 21 November 2014 / Accepted: 26 November 2014 / Published: 9 December 2014
Cited by 1 | PDF Full-text (466 KB) | HTML Full-text | XML Full-text
Abstract
Gamma tocopherol (gT) exhibits beneficial cardiovascular effects partly due to its anti-inflammatory activity. Important sources of gT are vegetable oils. However, little is known to what extent gT can be transferred into marine animal species such as Atlantic salmon by feeding. Therefore, in
[...] Read more.
Gamma tocopherol (gT) exhibits beneficial cardiovascular effects partly due to its anti-inflammatory activity. Important sources of gT are vegetable oils. However, little is known to what extent gT can be transferred into marine animal species such as Atlantic salmon by feeding. Therefore, in this study we have investigated the transfer of dietary gT into salmon. To this end, fish were fed a diet supplemented with 170 ppm gT for 16 weeks whereby alpha tocopherol levels were adjusted to 190 ppm in this and the control diet. Feeding gT-rich diets resulted in a three-fold increase in gT concentrations in the liver and fillet compared to non-gT-supplemented controls. Tissue alpha tocopherol levels were not decreased indicating no antagonistic interaction between gamma- and alpha tocopherol in salmon. The concentration of total omega 3 fatty acids slightly increased in response to dietary gT. Furthermore, dietary gT significantly decreased malondialdehyde in the fillet, determined as a biomarker of lipid peroxidation. In the liver of gT fed salmon we observed an overall down-regulation of genes involved in lipid homeostasis. Additionally, gT improved the antioxidant capacity by up-regulating Gpx4a gene expression in the pyloric caeca. We suggest that Atlantic salmon may provide a marine functional source capable of enriching gT for human consumption. Full article
(This article belongs to the Special Issue Marine Functional Food Products - Cardiovascular Diseases)
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Open AccessArticle Characterisation of Non-Autoinducing Tropodithietic Acid (TDA) Production from Marine Sponge Pseudovibrio Species
Mar. Drugs 2014, 12(12), 5960-5978; doi:10.3390/md12125960
Received: 15 September 2014 / Revised: 5 November 2014 / Accepted: 12 November 2014 / Published: 10 December 2014
Cited by 15 | PDF Full-text (1184 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
The search for new antimicrobial compounds has gained added momentum in recent years, paralleled by the exponential rise in resistance to most known classes of current antibiotics. While modifications of existing drugs have brought some limited clinical success, there remains a critical need
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The search for new antimicrobial compounds has gained added momentum in recent years, paralleled by the exponential rise in resistance to most known classes of current antibiotics. While modifications of existing drugs have brought some limited clinical success, there remains a critical need for new classes of antimicrobial compound to which key clinical pathogens will be naive. This has provided the context and impetus to marine biodiscovery programmes that seek to isolate and characterize new activities from the aquatic ecosystem. One new antibiotic to emerge from these initiatives is the antibacterial compound tropodithietic acid (TDA). The aim of this study was to provide insight into the bioactivity of and the factors governing the production of TDA in marine Pseudovibrio isolates from a collection of marine sponges. The TDA produced by these Pseudovibrio isolates exhibited potent antimicrobial activity against a broad spectrum of clinical pathogens, while TDA tolerance was frequent in non-TDA producing marine isolates. Comparative genomics analysis suggested a high degree of conservation among the tda biosynthetic clusters while expression studies revealed coordinated regulation of TDA synthesis upon transition from log to stationary phase growth, which was not induced by TDA itself or by the presence of the C10-acyl homoserine lactone quorum sensing signal molecule. Full article
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Open AccessArticle Customizing Properties of β-Chitin in Squid Pen (Gladius) by Chemical Treatments
Mar. Drugs 2014, 12(12), 5979-5992; doi:10.3390/md12125979
Received: 18 September 2014 / Revised: 3 December 2014 / Accepted: 4 December 2014 / Published: 15 December 2014
Cited by 6 | PDF Full-text (916 KB) | HTML Full-text | XML Full-text
Abstract
The squid pen (gladius) from the Loligo vulgaris was used for preparation of β-chitin materials characterized by different chemical, micro- and nano-structural properties that preserved, almost completely the macrostructural and the mechanical ones. The β-chitin materials obtained by alkaline treatment showed porosity, wettability
[...] Read more.
The squid pen (gladius) from the Loligo vulgaris was used for preparation of β-chitin materials characterized by different chemical, micro- and nano-structural properties that preserved, almost completely the macrostructural and the mechanical ones. The β-chitin materials obtained by alkaline treatment showed porosity, wettability and swelling that are a function of the duration of the treatment. Microscopic, spectroscopic and synchrotron X-ray diffraction techniques showed that the chemical environment of the N-acetyl groups of the β-chitin chains changes after the thermal alkaline treatment. As a consequence, the crystalline packing of the β-chitin is modified, due to the intercalation of water molecules between β-chitin sheets. Potential applications of these β-chitin materials range from the nanotechnology to the regenerative medicine. The use of gladii, which are waste products of the fishing industry, has also important environmental implications. Full article
(This article belongs to the Special Issue Marine Biomaterials)
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Open AccessArticle Three New Asperentin Derivatives from the Algicolous Fungus Aspergillus sp. F00785
Mar. Drugs 2014, 12(12), 5993-6002; doi:10.3390/md12125993
Received: 21 October 2014 / Revised: 21 November 2014 / Accepted: 4 December 2014 / Published: 15 December 2014
Cited by 5 | PDF Full-text (582 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
Three new asperentin-type compounds, 6-O-α-d-ribosylasperentin (1) and 6-O-α-d-ribosyl-8-O-methylasperentin (2) and 5-hydroxyl-6-O-methylasperentin (3), along with asperentin (4) and its known analogues (59), were isolated
[...] Read more.
Three new asperentin-type compounds, 6-O-α-d-ribosylasperentin (1) and 6-O-α-d-ribosyl-8-O-methylasperentin (2) and 5-hydroxyl-6-O-methylasperentin (3), along with asperentin (4) and its known analogues (59), were isolated from a halotolerant Aspergillus sp. strain F00785, an endotrophic fungus from marine alga. Their structures were determined using extensive NMR and HRESIMS spectroscopic analysis, including the X-ray crystallographic data for the assignment of the absolute configurations of compound 9. Compound 4 exhibited highly potent inhibitory activity against crop pathogens, Colletotrichum gleosporioides Penz. and Colletotrichum gleosporioides (Penz.) Sacc. Full article
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Open AccessArticle Aaptamine Derivatives with Antifungal and Anti-HIV-1 Activities from the South China Sea Sponge Aaptos aaptos
Mar. Drugs 2014, 12(12), 6003-6013; doi:10.3390/md12126003
Received: 15 October 2014 / Revised: 3 November 2014 / Accepted: 2 December 2014 / Published: 16 December 2014
Cited by 7 | PDF Full-text (525 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
Five new alkaloids of aaptamine family, compounds (15) and three known derivatives (68), have been isolated from the South China Sea sponge Aaptos aaptos. The structures of all compounds were unambiguously elucidated by spectroscopic
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Five new alkaloids of aaptamine family, compounds (15) and three known derivatives (68), have been isolated from the South China Sea sponge Aaptos aaptos. The structures of all compounds were unambiguously elucidated by spectroscopic analyses, as well as by comparison with the literature data. Compounds 12 are characterized with triazapyrene lactam skeleton, whereas compounds 45 share an imidazole-fused aaptamine moiety. These compounds were evaluated in antifungal and anti-HIV-1 assays. Compounds 3, 7, and 8 showed antifungal activity against six fungi, with MIC values in the range of 4 to 64 μg/mL. Compounds 78 exhibited anti-HIV-1 activity, with inhibitory rates of 88.0% and 72.3%, respectively, at a concentration of 10 μM. Full article
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Open AccessArticle Secocrassumol, a seco-Cembranoid from the Dongsha Atoll Soft Coral Lobophytum crassum
Mar. Drugs 2014, 12(12), 6028-6037; doi:10.3390/md12126028
Received: 16 October 2014 / Revised: 7 November 2014 / Accepted: 28 November 2014 / Published: 17 December 2014
Cited by 7 | PDF Full-text (504 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
Chemical investigations on the Dongsha Atoll soft coral Lobophytum crassum led to the purification of a new seco-cembranoid, secocrassumol. The structural elucidation was established by extensive NMR, HRESIMS and CD data. The absolute configuration at C-12 was determined as S using a
[...] Read more.
Chemical investigations on the Dongsha Atoll soft coral Lobophytum crassum led to the purification of a new seco-cembranoid, secocrassumol. The structural elucidation was established by extensive NMR, HRESIMS and CD data. The absolute configuration at C-12 was determined as S using a modified Mosher’s acylation. Secocrassumol differs from previously known marine seco-cembranoid in that it possesses an unprecedented skeleton functionalized at C11-C12 bond cleavage. Secocrassumol showed antiviral activity against human cytomegalovirus (HCMV) with an IC50 value of 5.0 μg/mL. Full article
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Open AccessArticle Anti-Mycobacterial Nucleoside Antibiotics from a Marine-Derived Streptomyces sp. TPU1236A
Mar. Drugs 2014, 12(12), 6102-6112; doi:10.3390/md12126102
Received: 30 October 2014 / Revised: 9 December 2014 / Accepted: 10 December 2014 / Published: 17 December 2014
Cited by 13 | PDF Full-text (663 KB) | HTML Full-text | XML Full-text
Abstract
Five new nucleoside antibiotics, named streptcytosines A–E (15), and six known compounds, de-amosaminyl-cytosamine (6), plicacetin (7), bamicetin (8), amicetin (9), collismycin B (10), and SF2738 C (11),
[...] Read more.
Five new nucleoside antibiotics, named streptcytosines A–E (15), and six known compounds, de-amosaminyl-cytosamine (6), plicacetin (7), bamicetin (8), amicetin (9), collismycin B (10), and SF2738 C (11), were isolated from a culture broth of Streptomyces sp. TPU1236A collected in Okinawa, Japan. The structures of new compounds were elucidated on the basis of their spectroscopic data (HRFABMS, IR, UV, and 2D NMR experiments including 1H-1H COSY, HMQC, HMBC, and NOESY spectra). Streptcytosine A (1) belonged to the amicetin group antibiotics, and streptcytosines B–E (25) were derivatives of de-amosaminyl-cytosamine (6), 2,3,6-trideoxyglucopyranosyl cytosine. Compound 1 inhibited the growth of Mycobacterium smegmatis (MIC = 32 µg/mL), while compounds 25 were not active at 50 µg/disc. Bamicetin (8) and amicetin (9) showed the MICs of 16 and 8 µg/mL, respectively. Full article
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Open AccessArticle Territrem and Butyrolactone Derivatives from a Marine-Derived Fungus Aspergillus Terreus
Mar. Drugs 2014, 12(12), 6113-6124; doi:10.3390/md12126113
Received: 17 September 2014 / Revised: 24 November 2014 / Accepted: 8 December 2014 / Published: 17 December 2014
Cited by 14 | PDF Full-text (567 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
Seventeen lactones including eight territrem derivatives (18) and nine butyrolactone derivatives (917) were isolated from a marine-derived fungus Aspergillus terreus SCSGAF0162 under solid-state fermentation of rice. Compounds 13 and 910
[...] Read more.
Seventeen lactones including eight territrem derivatives (18) and nine butyrolactone derivatives (917) were isolated from a marine-derived fungus Aspergillus terreus SCSGAF0162 under solid-state fermentation of rice. Compounds 13 and 910 were new, and their structures were elucidated by spectroscopic analysis. The acetylcholinesterase inhibitory activity and antiviral activity of compounds 117 were evaluated. Among them, compounds 1 and 2 showed strong inhibitory activity against acetylcholinesterase with IC50 values of 4.2 ± 0.6, 4.5 ± 0.6 nM, respectively. This is the first time it has been reported that 3, 6, 10, 12 had evident antiviral activity towards HSV-1 with IC50 values of 16.4 ± 0.6, 6.34 ± 0.4, 21.8 ± 0.8 and 28.9 ± 0.8 μg·mL−1, respectively. Antifouling bioassay tests showed that compounds 1, 11, 12, 15 had potent antifouling activity with EC50 values of 12.9 ± 0.5, 22.1 ± 0.8, 7.4 ± 0.6, 16.1 ± 0.6 μg·mL−1 toward barnacle Balanus amphitrite larvae, respectively. Full article
(This article belongs to the Special Issue Bioactive Compounds from Marine Fungi)
Open AccessArticle Astaxanthin Activates Nuclear Factor Erythroid-Related Factor 2 and the Antioxidant Responsive Element (Nrf2-ARE) Pathway in the Brain after Subarachnoid Hemorrhage in Rats and Attenuates Early Brain Injury
Mar. Drugs 2014, 12(12), 6125-6141; doi:10.3390/md12126125
Received: 9 October 2014 / Revised: 19 November 2014 / Accepted: 8 December 2014 / Published: 18 December 2014
Cited by 23 | PDF Full-text (1175 KB) | HTML Full-text | XML Full-text
Abstract
Astaxanthin (ATX) has been proven to ameliorate early brain injury (EBI) after experimental subarachnoid hemorrhage (SAH) by modulating cerebral oxidative stress. This study was performed to assess the effect of ATX on the Nrf2-ARE pathway and to explore the underlying molecular mechanisms of
[...] Read more.
Astaxanthin (ATX) has been proven to ameliorate early brain injury (EBI) after experimental subarachnoid hemorrhage (SAH) by modulating cerebral oxidative stress. This study was performed to assess the effect of ATX on the Nrf2-ARE pathway and to explore the underlying molecular mechanisms of antioxidant properties of ATX in EBI after SAH. A total of 96 male SD rats were randomly divided into four groups. Autologous blood was injected into the prechiasmatic cistern of the rat to induce an experimental SAH model. Rats in each group were sacrificed at 24 h after SAH. Expressions of Nrf2 and heme oxygenase-1 (HO-1) were measured by Western blot and immunohistochemistry analysis. The mRNA levels of HO-1, NAD (P) H: quinone oxidoreductase 1 (NQO-1), and glutathione S-transferase-α1 (GST-α1) were determined by real-time polymerase chain reaction (PCR). It was observed that administration of ATX post-SAH could up-regulate the cortical expression of these agents, mediated in the Nrf2-ARE pathway at both pretranscriptional and posttranscriptional levels. Meanwhile, oxidative damage was reduced. Furthermore, ATX treatment significantly attenuated brain edema, blood–brain barrier (BBB) disruption, cellular apoptosis, and neurological dysfunction in SAH models. This study demonstrated that ATX treatment alleviated EBI in SAH model, possibly through activating the Nrf2-ARE pathway by inducing antioxidant and detoxifying enzymes. Full article
Open AccessArticle Briarane Diterpenoids from the Gorgonian Dichotella gemmacea
Mar. Drugs 2014, 12(12), 6178-6189; doi:10.3390/md12126178
Received: 21 October 2014 / Revised: 27 November 2014 / Accepted: 8 December 2014 / Published: 18 December 2014
Cited by 3 | PDF Full-text (189 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
Seven new briarane diterpenoids, gemmacolides AS-AY (17), were isolated together with ten known analogues (817) from the South China Sea gorgonian Dichotella gemmacea. The structures of the new compounds were elucidated by the
[...] Read more.
Seven new briarane diterpenoids, gemmacolides AS-AY (17), were isolated together with ten known analogues (817) from the South China Sea gorgonian Dichotella gemmacea. The structures of the new compounds were elucidated by the detailed analysis of spectroscopic data and comparison with reported data. The absolute configuration of compounds was determined based on electronic circular dichroism (ECD) experiments and genetic correlations as well. Compounds 15 and 16 were reported for the first time for the gorgonian. In the preliminary in vitro bioassays, compound 5 showed potential growth inhibitory activity against MG63 cells. Full article
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Open AccessArticle Multiple Beneficial Lipids Including Lecithin Detected in the Edible Invasive Mollusk Crepidula fornicata from the French Northeastern Atlantic Coast
Mar. Drugs 2014, 12(12), 6254-6268; doi:10.3390/md12126254
Received: 29 September 2014 / Revised: 8 December 2014 / Accepted: 10 December 2014 / Published: 22 December 2014
Cited by 3 | PDF Full-text (400 KB) | HTML Full-text | XML Full-text
Abstract
The invasive mollusk Crepidula fornicata, occurring in large amounts in bays along the French Northeastern Atlantic coasts, may have huge environmental effects in highly productive ecosystems where shellfish are exploited. The present study aims at determining the potential economic value of this marine
[...] Read more.
The invasive mollusk Crepidula fornicata, occurring in large amounts in bays along the French Northeastern Atlantic coasts, may have huge environmental effects in highly productive ecosystems where shellfish are exploited. The present study aims at determining the potential economic value of this marine species in terms of exploitable substances with high added value. Lipid content and phospholipid (PL) composition of this mollusk collected on the Bourgneuf Bay were studied through four seasons. Winter specimens contained the highest lipid levels (5.3% dry weight), including 69% of PLs. Phosphatidylcholine (PC) was the major PL class all year, accounting for 63.9% to 88.9% of total PLs. Consequently, the winter specimens were then investigated for PL fatty acids (FAs), and free sterols. Dimethylacetals (DMAs) were present (10.7% of PL FA + DMA mixture) revealing the occurrence of plasmalogens. More than forty FAs were identified, including 20:5n-3 (9.4%) and 22:6n-3 (7.3%) acids. Fourteen free sterols were present, including cholesterol at 31.3% of the sterol mixture and about 40% of phytosterols. These data on lipids of C. fornicata demonstrate their positive attributes for human nutrition and health. The PL mixture, rich in PC and polyunsaturated FAs, offers an interesting alternative source of high value-added marine lecithin. Full article
(This article belongs to the Special Issue Marine Lipids)
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Review

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Open AccessReview Alternative Methods for the Detection of Emerging Marine Toxins: Biosensors, Biochemical Assays and Cell-Based Assays
Mar. Drugs 2014, 12(12), 5719-5763; doi:10.3390/md12125719
Received: 5 September 2014 / Revised: 11 November 2014 / Accepted: 11 November 2014 / Published: 26 November 2014
Cited by 13 | PDF Full-text (644 KB) | HTML Full-text | XML Full-text
Abstract
The emergence of marine toxins in water and seafood may have a considerable impact on public health. Although the tendency in Europe is to consolidate, when possible, official reference methods based on instrumental analysis, the development of alternative or complementary methods providing functional
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The emergence of marine toxins in water and seafood may have a considerable impact on public health. Although the tendency in Europe is to consolidate, when possible, official reference methods based on instrumental analysis, the development of alternative or complementary methods providing functional or toxicological information may provide advantages in terms of risk identification, but also low cost, simplicity, ease of use and high-throughput analysis. This article gives an overview of the immunoassays, cell-based assays, receptor-binding assays and biosensors that have been developed for the screening and quantification of emerging marine toxins: palytoxins, ciguatoxins, cyclic imines and tetrodotoxins. Their advantages and limitations are discussed, as well as their possible integration in research and monitoring programs. Full article
(This article belongs to the Special Issue Emerging Marine Toxins)
Open AccessReview Marine Nucleosides: Structure, Bioactivity, Synthesis and Biosynthesis
Mar. Drugs 2014, 12(12), 5817-5838; doi:10.3390/md12125817
Received: 4 August 2014 / Revised: 20 November 2014 / Accepted: 21 November 2014 / Published: 2 December 2014
Cited by 13 | PDF Full-text (946 KB) | HTML Full-text | XML Full-text
Abstract
Nucleosides are glycosylamines that structurally form part of nucleotide molecules, the building block of DNA and RNA. Both nucleosides and nucleotides are vital components of all living cells and involved in several key biological processes. Some of these nucleosides have been obtained from
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Nucleosides are glycosylamines that structurally form part of nucleotide molecules, the building block of DNA and RNA. Both nucleosides and nucleotides are vital components of all living cells and involved in several key biological processes. Some of these nucleosides have been obtained from a variety of marine resources. Because of the biological importance of these compounds, this review covers 68 marine originated nucleosides and their synthetic analogs published up to June 2014. The review will focus on the structures, bioactivities, synthesis and biosynthetic processes of these compounds. Full article
Open AccessReview Marine Origin Collagens and Its Potential Applications
Mar. Drugs 2014, 12(12), 5881-5901; doi:10.3390/md12125881
Received: 1 August 2014 / Revised: 11 November 2014 / Accepted: 19 November 2014 / Published: 5 December 2014
Cited by 35 | PDF Full-text (623 KB) | HTML Full-text | XML Full-text
Abstract
Collagens are the most abundant high molecular weight proteins in both invertebrate and vertebrate organisms, including mammals, and possess mainly a structural role, existing different types according with their specific organization in distinct tissues. From this, they have been elected as one of
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Collagens are the most abundant high molecular weight proteins in both invertebrate and vertebrate organisms, including mammals, and possess mainly a structural role, existing different types according with their specific organization in distinct tissues. From this, they have been elected as one of the key biological materials in tissue regeneration approaches. Also, industry is constantly searching for new natural sources of collagen and upgraded methodologies for their production. The most common sources are from bovine and porcine origin, but other ways are making their route, such as recombinant production, but also extraction from marine organisms like fish. Different organisms have been proposed and explored for collagen extraction, allowing the sustainable production of different types of collagens, with properties depending on the kind of organism (and their natural environment) and extraction methodology. Such variety of collagen properties has been further investigated in different ways to render a wide range of applications. The present review aims to shed some light on the contribution of marine collagens for the scientific and technological development of this sector, stressing the opportunities and challenges that they are and most probably will be facing to assume a role as an alternative source for industrial exploitation. Full article
(This article belongs to the Special Issue Marine Biomaterials)
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Open AccessReview Marine Pseudovibrio sp. as a Novel Source of Antimicrobials
Mar. Drugs 2014, 12(12), 5916-5929; doi:10.3390/md12125916
Received: 25 August 2014 / Revised: 24 November 2014 / Accepted: 25 November 2014 / Published: 9 December 2014
Cited by 6 | PDF Full-text (565 KB) | HTML Full-text | XML Full-text
Abstract
Antibiotic resistance among pathogenic microorganisms is becoming ever more common. Unfortunately, the development of new antibiotics which may combat resistance has decreased. Recently, however the oceans and the marine animals that reside there have received increased attention as a potential source for natural
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Antibiotic resistance among pathogenic microorganisms is becoming ever more common. Unfortunately, the development of new antibiotics which may combat resistance has decreased. Recently, however the oceans and the marine animals that reside there have received increased attention as a potential source for natural product discovery. Many marine eukaryotes interact and form close associations with microorganisms that inhabit their surfaces, many of which can inhibit the attachment, growth or survival of competitor species. It is the bioactive compounds responsible for the inhibition that is of interest to researchers on the hunt for novel bioactives. The genus Pseudovibrio has been repeatedly identified from the bacterial communities isolated from marine surfaces. In addition, antimicrobial activity assays have demonstrated significant antimicrobial producing capabilities throughout the genus. This review will describe the potency, spectrum and possible novelty of the compounds produced by these bacteria, while highlighting the capacity for this genus to produce natural antimicrobial compounds which could be employed to control undesirable bacteria in the healthcare and food production sectors. Full article
(This article belongs to the Special Issue Bioactive Compounds from Marine Microbes)
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Open AccessReview Nano- and Microdelivery Systems for Marine Bioactive Lipids
Mar. Drugs 2014, 12(12), 6014-6027; doi:10.3390/md12126014
Received: 11 October 2014 / Revised: 24 November 2014 / Accepted: 28 November 2014 / Published: 17 December 2014
Cited by 6 | PDF Full-text (530 KB) | HTML Full-text | XML Full-text
Abstract
There is an increasing body of evidence of the positive impact of several marine lipids on human health. These compounds, which include ω-3 polyunsaturated fatty acids, have been shown to improve blood lipid profiles and exert anti-inflammatory and cardioprotective effects. The high instability
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There is an increasing body of evidence of the positive impact of several marine lipids on human health. These compounds, which include ω-3 polyunsaturated fatty acids, have been shown to improve blood lipid profiles and exert anti-inflammatory and cardioprotective effects. The high instability of these compounds to oxidative deterioration and their hydrophobicity have a drastic impact in their pharmacokinetics. Thus, the bioavailability of these compounds may be affected, resulting in their inability to reach the target sites at effective concentrations. In this regard, micro/nanoparticles can offer a wide range of solutions that can prevent the degradation of targeted molecules, increase their absorption, uptake and bioavailability. In this work we will present the options currently available concerning micro- and nanodelivery systems for marine lipids; with emphasis on micro/nanoparticles; such as micro/nanocapsules and emulsions. A wide range of bottom-up approaches using casein, chitosan, cyclodextrins, among others; will be discussed. Full article
(This article belongs to the Special Issue Marine Functional Food Products - Cardiovascular Diseases)
Open AccessReview Glycol Chitosan-Based Fluorescent Theranostic Nanoagents for Cancer Therapy
Mar. Drugs 2014, 12(12), 6038-6057; doi:10.3390/md12126038
Received: 9 October 2014 / Revised: 27 November 2014 / Accepted: 27 November 2014 / Published: 17 December 2014
Cited by 13 | PDF Full-text (1449 KB) | HTML Full-text | XML Full-text
Abstract
Theranostics is an integrated nanosystem that combines therapeutics with diagnostics in attempt to develop new personalized treatments with enhanced therapeutic efficacy and safety. As a promising therapeutic paradigm with cutting-edge technologies, theranostic agents are able to simultaneously deliver therapeutic drugs and diagnostic imaging
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Theranostics is an integrated nanosystem that combines therapeutics with diagnostics in attempt to develop new personalized treatments with enhanced therapeutic efficacy and safety. As a promising therapeutic paradigm with cutting-edge technologies, theranostic agents are able to simultaneously deliver therapeutic drugs and diagnostic imaging agents and also monitor the response to therapy. Polymeric nanosystems have been intensively explored for biomedical applications to diagnose and treat various cancers. In recent years, glycol chitosan-based nanoagents have been developed as dual-purpose materials for simultaneous diagnosis and therapy. They have shown great potential in cancer therapies, such as chemotherapeutics and nucleic acid and photodynamic therapies. In this review, we summarize the recent progress and potential applications of glycol chitosan-based fluorescent theranostic nanoagents for cancer treatments and discuss their possible underlying mechanisms. Full article
(This article belongs to the Special Issue Advances in Marine Chitin and Chitosan) Printed Edition available
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Open AccessReview Conotoxin Gene Superfamilies
Mar. Drugs 2014, 12(12), 6058-6101; doi:10.3390/md12126058
Received: 28 October 2014 / Revised: 29 November 2014 / Accepted: 4 December 2014 / Published: 17 December 2014
Cited by 39 | PDF Full-text (2366 KB) | HTML Full-text | XML Full-text
Abstract
Conotoxins are the peptidic components of the venoms of marine cone snails (genus Conus). They are remarkably diverse in terms of structure and function. Unique potency and selectivity profiles for a range of neuronal targets have made several conotoxins valuable as research
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Conotoxins are the peptidic components of the venoms of marine cone snails (genus Conus). They are remarkably diverse in terms of structure and function. Unique potency and selectivity profiles for a range of neuronal targets have made several conotoxins valuable as research tools, drug leads and even therapeutics, and has resulted in a concerted and increasing drive to identify and characterise new conotoxins. Conotoxins are translated from mRNA as peptide precursors, and cDNA sequencing is now the primary method for identification of new conotoxin sequences. As a result, gene superfamily, a classification based on precursor signal peptide identity, has become the most convenient method of conotoxin classification. Here we review each of the described conotoxin gene superfamilies, with a focus on the structural and functional diversity present in each. This review is intended to serve as a practical guide to conotoxin superfamilies and to facilitate interpretation of the increasing number of conotoxin precursor sequences being identified by targeted-cDNA sequencing and more recently high-throughput transcriptome sequencing. Full article
(This article belongs to the Special Issue Marine Peptides and Their Mimetics)
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Open AccessReview Synthetic Approaches to the Lamellarins—A Comprehensive Review
Mar. Drugs 2014, 12(12), 6142-6177; doi:10.3390/md12126142
Received: 3 November 2014 / Revised: 1 December 2014 / Accepted: 5 December 2014 / Published: 18 December 2014
Cited by 16 | PDF Full-text (5436 KB) | HTML Full-text | XML Full-text
Abstract
The present review discusses the known synthetic routes to the lamellarin alkaloids published until 2014. It begins with syntheses of the structurally simpler type-II lamellarins and then focuses on the larger class of the 5,6-saturated and -unsaturated type-I lamellarins. The syntheses are grouped
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The present review discusses the known synthetic routes to the lamellarin alkaloids published until 2014. It begins with syntheses of the structurally simpler type-II lamellarins and then focuses on the larger class of the 5,6-saturated and -unsaturated type-I lamellarins. The syntheses are grouped by the strategy employed for the assembly of the central pyrrole ring. Full article
(This article belongs to the Special Issue Synthesis around Marine Natural Products)
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Open AccessReview Impact of DHA on Metabolic Diseases from Womb to Tomb
Mar. Drugs 2014, 12(12), 6190-6212; doi:10.3390/md12126190
Received: 9 October 2014 / Revised: 25 November 2014 / Accepted: 11 December 2014 / Published: 18 December 2014
Cited by 5 | PDF Full-text (637 KB) | HTML Full-text | XML Full-text
Abstract
Long chain polyunsaturated fatty acids (LC-PUFAs) are important mediators in improving and maintaining human health over the total lifespan. One topic we especially focus on in this review is omega-3 LC-PUFA docosahexaenoic acid (DHA). Adequate DHA levels are essential during neurodevelopment and, in
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Long chain polyunsaturated fatty acids (LC-PUFAs) are important mediators in improving and maintaining human health over the total lifespan. One topic we especially focus on in this review is omega-3 LC-PUFA docosahexaenoic acid (DHA). Adequate DHA levels are essential during neurodevelopment and, in addition, beneficial in cognitive processes throughout life. We review the impact of DHA on societal relevant metabolic diseases such as cardiovascular diseases, obesity, and diabetes mellitus type 2 (T2DM). All of these are risk factors for cognitive decline and dementia in later life. DHA supplementation is associated with a reduced incidence of both stroke and atherosclerosis, lower bodyweight and decreased T2DM prevalence. These findings are discussed in the light of different stages in the human life cycle: childhood, adolescence, adulthood and in later life. From this review, it can be concluded that DHA supplementation is able to inhibit pathologies like obesity and cardiovascular disease. DHA could be a dietary protector against these metabolic diseases during a person’s entire lifespan. However, supplementation of DHA in combination with other dietary factors is also effective. The efficacy of DHA depends on its dose as well as on the duration of supplementation, sex, and age. Full article
(This article belongs to the Special Issue Marine Functional Food Products - Cardiovascular Diseases)
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Open AccessReview An Update on 2,5-Diketopiperazines from Marine Organisms
Mar. Drugs 2014, 12(12), 6213-6235; doi:10.3390/md12126213
Received: 14 September 2014 / Revised: 5 December 2014 / Accepted: 9 December 2014 / Published: 19 December 2014
Cited by 20 | PDF Full-text (808 KB) | HTML Full-text | XML Full-text
Abstract
2,5-Diketopiperazines (2,5-DKPs) are an important category of structurally diverse cyclic dipeptides with prominent biological properties. These 2,5-DKPs have been obtained from a variety of natural resources, including marine organisms. Because of the increasing numbers and biological importance of these compounds, this review covers
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2,5-Diketopiperazines (2,5-DKPs) are an important category of structurally diverse cyclic dipeptides with prominent biological properties. These 2,5-DKPs have been obtained from a variety of natural resources, including marine organisms. Because of the increasing numbers and biological importance of these compounds, this review covers 90 marine originated 2,5-DKPs that were reported from 2009 to the first half-year of 2014. The review will focus on the structure characterizations, biological properties and proposed biosynthetic processes of these compounds. Full article
Open AccessReview Design of Chitosan and Its Water Soluble Derivatives-Based Drug Carriers with Polyelectrolyte Complexes
Mar. Drugs 2014, 12(12), 6236-6253; doi:10.3390/md12126236
Received: 9 October 2014 / Revised: 11 December 2014 / Accepted: 12 December 2014 / Published: 19 December 2014
Cited by 13 | PDF Full-text (535 KB) | HTML Full-text | XML Full-text
Abstract
Chitosan, the cationic polysaccharide derived from the natural polysaccharide chitin, has been studied as a biomaterial for more than two decades. As a polycationic polymer with favorable properties, it has been widely used to form polyelectrolyte complexes with polyanions for various applications in
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Chitosan, the cationic polysaccharide derived from the natural polysaccharide chitin, has been studied as a biomaterial for more than two decades. As a polycationic polymer with favorable properties, it has been widely used to form polyelectrolyte complexes with polyanions for various applications in drug delivery fields. In recent years, a growing number of studies have been focused on the preparation of polyelectrolyte complexes based on chitosan and its water soluble derivatives. They have been considered well-suited as biomaterials for a number of vital drug carriers with targeted/controlled release profiles, e.g., films, capsules, microcapsules. In this work, an overview highlights not only the favorable properties of chitosan and its water soluble derivatives but also the good performance of the polyelectrolyte complexes produced based on chitosan. Their various types of applications as drug carriers are reviewed in detail. Full article
(This article belongs to the Special Issue Advances in Marine Chitin and Chitosan) Printed Edition available
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