Gliotoxin from Aspergillus fumigatus reverses epithelial to mesenchymal transition: implications in renal fibrosis.

Fibrosis is generally characterized by an excessive accumulation and deposition of extracellular matrix (ECM) that progressively leads to the destruction of functional nephrons of the kidney. Current study is aimed to propose a probable antifibrotic mechanism of gliotoxin, isolated from marine Aspergillus fumigatus strain, in proximal tubule renal epithelial cells by inhibiting HIF-1α, Ang-II and NF-κB in a dose dependent manner. GTX at a concentration of 1.6 ng/ml also showed more than 80% cell viability. Scanning Electron Microscopy, fluorescence microscopy, FACS, mRNA and protein profiles further confirmed that gliotoxin reverses the epithelial to mesenchymal transition in HK-2 cells by scavenging the production of reactive oxygen species (g=69.7) when compared to negative control (g=467.74). Under the light of obtained results, the present study holds immense promise for the biomedical implication of the fungal metabolite, Gliotoxin in medicine for treating various clinical cases of renal fibrosis.

Chitosan-alginate biocomposite containing fucoidan for bone tissue engineering.

Over the last few years, significant research has been conducted in the construction of artificial bone scaffolds. In the present study, different types of polymer scaffolds, such as chitosan-alginate (Chi-Alg) and chitosan-alginate with fucoidan (Chi-Alg-fucoidan), were developed by a freeze-drying method, and each was characterized as a bone graft substitute. The porosity, water uptake and retention ability of the prepared scaffolds showed similar efficacy. The pore size of the Chi-Alg and Chi-Alg-fucoidan scaffolds were measured from scanning electron microscopy and found to be 62-490 and 56-437 µm, respectively. In vitro studies using the MG-63 cell line revealed profound cytocompatibility, increased cell proliferation and enhanced alkaline phosphatase secretion in the Chi-Alg-fucoidan scaffold compared to the Chi-Alg scaffold. Further, protein adsorption and mineralization were about two times greater in the Chi-Alg-fucoidan scaffold than the Chi-Alg scaffold. Hence, we suggest that Chi-Alg-fucoidan will be a promising biomaterial for bone tissue regeneration.

Green synthesis of α-aminophosphonate derivatives on a solid supported TiO2 -SiO2 catalyst and their anticancer activity.

Syntheses of a new series of biologically potent α-aminophosphonates were accomplished by one-pot Kabachnik-Fields reaction using TiO2-SiO2 as solid supported catalyst under microwave irradiation conditions. The chemical structures of all the newly synthesized compounds were confirmed by analytical and spectral (IR, 1H, 13C, 31P NMR, and mass) data. Their anticancer nature was evaluated by screening the in vitro activity on two human cancer cell lines, HeLa and SK-BR-3. Compounds 4i and 4o showed the best activity on these cancer cells even though the majority of the compounds, and particularly 4l and 4p, have good cytotoxic activity against them.

Chitosan reduced in-situ synthesis of gold nanoparticles on paper towards fabricating highly sensitive, stable uniform SERS substrates for sensing applications.

Surface-Enhanced Raman Spectroscopy (SERS) is a powerful surface-sensitive technique for molecular analysis. Its use is limited due to high cost, non-flexible rigid substrates such as silicon, alumina or glass and less reproducibility due to non-uniform surface. Recently, paper-based SERS substrates, a low-cost and highly flexible alternative, received significant attention. We report here a rapid, inexpensive method for chitosan-reduced, in-situ synthesis of gold nanoparticles (GNPs) on paper devices towards direct utilization as SERS substrates. GNPs have been prepared by reducing chloroauric acid with chitosan as a reducing and capping reagent on the cellulose-based paper surface at 100 °C, under the saturated humidity condition (100 % humidity). GNPs thus obtained were uniformly distributed on the surface and had fairly uniform particle size with a diameter of 10 ± 2 nm. Substrate coverage of resulting GNPs directly depended on the precursor's ratio, temperature and reaction time. Techniques such as TEM, SEM, and FE-SEM were utilized to determine the shape, size, and distribution of GNPs on paper substrate. SERS substrate produced by this simple, rapid, reproducible and robust method of chitosan-reduced, in situ synthesis of GNPs, showed exceptional performance and long-term stability, with a detection limit of up to 1 pM concentration of test analyte, R6G. Present paper-based SERS substrates are cost-effective, reproducible, flexible, and suitable for field applications.

Ready-to-use vertical flow paper device for instrument-free room temperature reverse transcription.

Paper-based nucleic acid detection and diagnosis are currently gaining much interest in point-of-care (POC) applications. The major steps involved in any nucleic acid amplification testing (NAAT) based diagnostics are nucleic acid isolation, reverse transcription (RT) (in the case of RNA), amplification and detection. RT is an important step in quantifying the viral load in case of disease diagnosis as well as quantifying gene expression levels in other molecular studies. cDNA synthesis is routinely carried out using a thermal cycler, with the process requiring temperatures between 40ºC to 65ºC. Here we report for the first time an instrument-free RT, performed at room temperature on cellulose-based paper devices. cDNA synthesis on paper was confirmed by RT-PCR and Sanger sequencing of the PCR products. Purified RNA from varied sources such as cell lysate, tissue and blood were used to test the methodology. Synthetic hepatitis C virus (HCV) RNA and human blood RNA were used as proof-of-concept to demonstrate the use of these devices in diagnostic applications. Further, ready-to-use paper-based reverse transcription (PRT) devices have been developed, wherein only the RNA sample is added on the device and the cDNA can be eluted after 30 min of incubation at room temperature. The devices were found to be stable for 30 days at - 20ºC storage. The cellulose-based PRT devices are simple, time saving and user-friendly for a complete instrument-free cDNA synthesis at room temperature.

Synthesis, characterization, DNA binding properties, fluorescence studies and toxic activity of cobalt(III) and ruthenium(II) polypyridyl complexes.

The new ligand 4-(isopropylbenzaldehyde)imidazo[4,5-f ][1,10]phenanthroline (ippip) and its complexes [Ru(phen)(2)(ippip)](2+)(1),[Co(phen)(2)(ippip)](3+)(2),[Ru(bpy)(2)(ippip)](2+)(3),[Co(bpy)(2)(ippip)](3+)(4)(bpy=2,2-bipyridine) and (phen=1,10-phenanthroline) were synthesized and characterized by ES(+)-MS, (1)H and (13)C NMR. The DNA binding properties of the four complexes were investigated by different spectrophotometric methods and viscosity measurements. The results suggest that complexes bind to calf thymus DNA (CT-DNA) through intercalation. When irradiated at 365 nm, the complexes promote the photocleavage of pBR322 DNA, and complex 1 cleaves DNA more effectively than 2, 3, 4 complexes under comparable experimental conditions. Furthermore, photocleavage studies reveal that singlet oxygen ((1)O(2)) plays a significant role in the photocleavage.

A novel method for fabrication of paper-based microfluidic devices using BSA-ink.

This paper describes the fabrication of paper-based microfluidic devices using a novel, inexpensive ink composed of bovine serum albumin (BSA), utilizing BSA's thermal denaturation and aggregation to create a hydrophobic barrier on Whatman® Grade 4 filter paper. A 20% aqueous solution of BSA was inked onto the paper using a pen plotter at moderate speed (5 cm/s) with desired shape and size followed by heating at 80 °C to denature the BSA leading to hydrophobic barriers formation, whereas below 80 °C the barrier layer is prone to collapse. The minimum line gap and line width of ~1 mm and ~1.3 mm were achieved. Finally, a proof-of-concept glucose sensing was shown while addressing the issue of the coffee ring effect using the biopolymer NanoCheck-ATH® from ChitoLytic Inc. The glucose concentration limit of detection (LOD) as low as 0.2 mg/mL was estimated. The developed technique offers ease of fabrication, high reproducibility, cost-effectiveness, and is environmentally friendly.

Complex target SELEX-based identification of DNA aptamers against Bungarus caeruleus venom for the detection of envenomation using a paper-based device.

Complex target SELEX always have been an intriguing approach to the scientific community, as it offers the potential discovery of novel biomarkers. We herein successfully performed SELEX on Bungarus caeruleus venom to develop a panel of highly affine aptamers that specifically recognizes the B. caeruleus (common krait) venom and was able to discriminate the B. caeruleus venom from Cobra, Russell's, and Saw-scaled viper's venom. The aptamers generated against the crude venom also lead to the identification of the specific component of the venom, which is ß-Bungarotoxin, a toxin uniquely present in the B. caeruleus venom. The best performing aptamer candidates were used as a molecular recognition element in a paper-based device and were able to detect as low as 2 ng krait venom in human serum background. The developed aptamer-based paper device can be used for potential point-of-care venom detection applications due to its simplicity and affordability.

Immense essence of excellence: marine microbial bioactive compounds.

Oceans have borne most of the biological activities on our planet. A number of biologically active compounds with varying degrees of action, such as anti-tumor, anti-cancer, anti-microtubule, anti-proliferative, cytotoxic, photo protective, as well as antibiotic and antifouling properties, have been isolated to date from marine sources. The marine environment also represents a largely unexplored source for isolation of new microbes (bacteria, fungi, actinomycetes, microalgae-cyanobacteria and diatoms) that are potent producers of bioactive secondary metabolites. Extensive research has been done to unveil the bioactive potential of marine microbes (free living and symbiotic) and the results are amazingly diverse and productive. Some of these bioactive secondary metabolites of microbial origin with strong antibacterial and antifungal activities are being intensely used as antibiotics and may be effective against infectious diseases such as HIV, conditions of multiple bacterial infections (penicillin, cephalosporines, streptomycin, and vancomycin) or neuropsychiatric sequelae. Research is also being conducted on the general aspects of biophysical and biochemical properties, chemical structures and biotechnological applications of the bioactive substances derived from marine microorganisms, and their potential use as cosmeceuticals and nutraceuticals. This review is an attempt to consolidate the latest studies and critical research in this field, and to showcase the immense competence of marine microbial flora as bioactive metabolite producers. In addition, the present review addresses some effective and novel approaches of procuring marine microbial compounds utilizing the latest screening strategies of drug discovery.

Marine antitumor drugs: status, shortfalls and strategies.

Cancer is considered as one of the deadliest diseases in the medical field. Apart from the preventive therapies, it is important to find a curative measure which holds no loopholes and acts accurately and precisely to curb cancer. Over the past few decades, there have been advances in this field and there are many antitumor compounds available on the market, which are of natural as well as synthetic origin. Marine chemotherapy is well recognized nowadays and profound development has been achieved by researchers to deal with different molecular pathways of tumors. However, the marine environment has been less explored for the production of safe and novel antitumor compounds. The reason is a number of shortfalls in this field. Though ample reviews cover the importance and applications of various anticancerous compounds from marine natural products, in the present review, we have tried to bring the current status of antitumor research based on marine inhibitors of cancer signaling pathways. In addition, focus has been placed on the shortfalls and probable strategies in the arena of marine antitumor drug discovery.

Cross-linked chitosan biofunctionalized paper-based microfluidic device towards long term stabilization of blood typing antibodies.

Long term stability of antibodies at room temperature is a major challenge in the commercialization of point-of-care devices for diagnostics. Since chitosan has been proven to be an excellent biofunctionalization material, the effects of four different biofunctionalization processes were studied to improve the room temperature stability of antibodies immobilized on chitosan modified paper-based microfluidic devices using blood typing antibodies as candidates. The devices used in this work have a flower-shaped design with 4 test zones at each corner. In three zones Anti-A, Anti-B, and Anti-D (Anti-Rh) antibodies are immobilized and the fouth zone represents the control (no antibodies) after biofunctionalization. The biofunctionalization of the paper devices was done with chitosan and chitosan cross-linked with sodium triphosphate pentabasic, glutaraldehyde, and sodium hydroxide. These devices were used for blood typing assays using real blood samples. A similar assay was also performed on unmodified (non-biofunctionalized) paper devices for comparison. Chitosan based biofunctionalized paper-devices showed better stability, up to 100 days as compared to 14 days on unmodified paper, at room temperature. Such biofunctionalized paper-based devices will be suitable for on-field and remote testing without any technical expertise and requirement for the cold chain.

Sulfated Polysaccharides from Macroalgae for Bone Tissue Regeneration.

BACKGROUND: Utilization of macroalgae has gained much attention in the field of pharmaceuticals, nutraceuticals, food and bioenergy. Macroalgae has been widely consumed in Asian countries as food from ancient days and proved that it has potential bioactive compounds which are responsible for its nutritional properties. Macroalgae consists of a diverse range of bioactive compounds including proteins, lipids, pigments, polysaccharides, etc. Polysaccharides from macroalgae have been utilized in food industries as gelling agents and drug excipients in the pharmaceutical industries owing to their biocompatibility and gel forming properties. Exploration of macroalgae derived sulfated polysaccharides in biomedical applications is increasing recently. METHODS: In the current review, we have provided information of three different sulfated polysaccharides such as carrageenan, fucoidan and ulvan and their isolation procedure (enzymatic precipitation, microwave assisted method, and enzymatic hydrolysis method), structural details, and their biomedical applications exclusively for bone tissue repair and regeneration. RESULTS: From the scientific results on sulfated polysaccharides from macroalgae, we conclude that sulfated polysaccharides have exceptional properties in terms of hydrogel-forming ability, scaffold formation, and mimicking the extracellular matrix, increasing alkaline phosphatase activity, enhancement of biomineralization ability and stem cell differentiation for bone tissue regeneration. CONCLUSION: Overall, sulfated polysaccharides from macroalgae may be promising biomaterials in bone tissue repair and regeneration.

Chitosan stabilized gold nanoparticle mediated self-assembled gliP nanobiosensor for diagnosis of Invasive Aspergillosis.

Diagnosis of Invasive Aspergillosis (IA) casused by Aspergillus fumigatus in miniaturized setting is challenging with great importance in human health. In this direction, we have designed a sensitive electrochemical nanobiosensor for diagnosis of IA through detecting the virulent glip target gene (glip-T) in a miniaturized experimetal setting. The sensor probe was fabricated using 1,6-Hexanedithiol and chitosan stabilized gold nanoparticle mediated self-assembly of glip probes (glip-P) on gold electrode. It was characterized by UV-visible spectroscopy, cyclic voltametry and electrochemical impedance spectroscopy. The ability of sensor to detect glip-T was analysed based on the hybridyzation reaction and the signal obtained using toluidine blue as indicator molecule. Analytical parameters were optimized in terms of glip-P concentration, temperature, reaction time, and concentration of toluidine blue. The biosensor showed the dynamic range between 1 × 10-14- 1 × 10-2 M with the detection limit of 0.32 ±â€¯0.01 × 10-14(RSD < 5.2%). The regeneration of biosensor was evaluated and the interference due to non-target oligonucleotide sequences was evaluated individualy as well as in mixed sample to validate the high selectivity of the designed sensor. The stability of the designed sensor was examined and practical applicability of biosensor was tested by detecting glip-T in real sample environment.

Chitosan as biomaterial in drug delivery and tissue engineering.

Chitin is one of the most abundant polysaccharide found on earth. The deacetylated form of chitin viz. chitosan has been reported for its various important pharmacological properties and its role in tissue engineering and regenerative medicine is also well documented. Chitosan based bone graft substitutes are biocompatible, biodegradable, osteoconductive, osteoinductive and structurally similar to bone, with excellent mechanical strength and cost effectiveness. Chitosan based hydrogels and wound healing bandages have also found a great market in the field of medicine. More recently, chitosan has gained popularity for its use as a matrix molecule for drug delivery and also finds an upcoming utility in the area of dentistry. The present article has tried to review the latest research on chitosan based tissue engineering constructs, drug delivery vehicles as well as dental care products. An attempt has also been made to discuss the various modifications of chitosan that enhance its use for a given set of applications which would pave a way for future applied research in the field of biomedical innovation and regenerative medicine.

Chitosan: An undisputed bio-fabrication material for tissue engineering and bio-sensing applications.

Biopolymers have been serving the mankind in various ways since long. Over the last few years, these polymers have found great demand in various domains which includes bio medicine, tissue engineering, bio sensor fabrications etc. because of their excellent bio compatibility. In this context, chitosan has found global attention due to its environmentally benign nature, biocompatibility, biodegradability, and ease of availability. In last one decade or so, extensive research in active biomaterials, like chitosan has led to the development of novel delivery systems for drugs, genes, and biomolecules; and regenerative medicine. Additionally, chitosan has also witnessed its usage in functionalization of biocompatible materials, nanoparticle (NP) synthesis, and immobilization of various bio-recognition elements (BREs) to form active bio-surfaces with great ease. Keeping these aspects in mind, we have written a comprehensive review which aims to acquaint its readers with the exceptional properties of chitosan and its usage in the domain of biomedicine, tissue engineering, and biosensor fabrication. Herein, we have briefly explained various aspects of direct utilization of chitosan and then presented vivid strategies towards formulation of chitosan based nanocomposites for biomedicine, tissue engineering, and biosensing applications.

Interaction of stem cells with nano hydroxyapatite-fucoidan bionanocomposites for bone tissue regeneration.

The combination of bioceramics with biopolymers are playing major role in the construction of artificial bone. Hydroxyapatite (HA) has been extensively studied as a material in bone repair and replacement in last two decades. In the present study, we have prepared the hydroxyapatite-fucoidan (HA-Fucoidan) nanocomposites by in situ chemical method and biologically characterized them for bone graft substitute. Biological results inferred that mineralization effect of HA-F nanocomposites shows significant enhancement compared to HA in adipose derived stem cell (ADSC). It may be due to the addition of fucoidan in the nanocomposites. The important gene expression such as osteocalcin, osteopontin, collagen and runx-2 were checked using ADSC with HA and HA-fucoidan nanocomposites and the results show that the enhancements were found at 7th day. Furthermore, we have performed in vivo study of HA-fucoidan nanocomposites with rabbit model and a slight amount of bone formation was observed in HA-fucoidan nanocomposites. Herewith, we suggest that HA-fucoidan nanocomposites will be good biomaterials for bone repair/replacement in future.

Alginate composites for bone tissue engineering: a review.

Bone is a complex and hierarchical tissue consisting of nano hydroxyapatite and collagen as major portion. Several attempts have been made to prepare the artificial bone so as to replace the autograft and allograft treatment. Tissue engineering is a promising approach to solve the several issues and is also useful in the construction of artificial bone with materials including polymer, ceramics, metals, cells and growth factors. Composites consisting of polymer-ceramics, best mimic the natural functions of bone. Alginate, an anionic polymer owing enormous biomedical applications, is gaining importance particularly in bone tissue engineering due to its biocompatibility and gel forming properties. Several composites such as alginate-polymer (PLGA, PEG and chitosan), alginate-protein (collagen and gelatin), alginate-ceramic, alginate-bioglass, alginate-biosilica, alginate-bone morphogenetic protein-2 and RGD peptides composite have been investigated till date. These alginate composites show enhanced biochemical significance in terms of porosity, mechanical strength, cell adhesion, biocompatibility, cell proliferation, alkaline phosphatase increase, excellent mineralization and osteogenic differentiation. Hence, alginate based composite biomaterials will be promising for bone tissue regeneration. This review will provide a broad overview of alginate preparation and its applications towards bone tissue engineering.

Polymer functionalized single walled carbon nanotubes mediated drug delivery of gliotoxin in cancer cells.

During recent years, significant development has been achieved in carbon nanotube conjugated with polymer system for drug delivery system (DDS). In the present study, we have prepared functionalized single walled carbon nanotube conjugated with chitooligosaccharide (f-SWNT-COS) as a Drug Delivery System. In addition, drug Gliotoxin (GTX) and targeting molecules (Lysozyme, p53 and Folic acid) have been incorporated into f-SWNT-COS. f-SWNTs-COS-GTX-p53, f-SWNTs-COS-GTX-lysozyme, f-SWNTs-COS-GTX-FA have been physiochemically characterized for DDS. FT-IR, SEM and TEM analysis confirmed the formation of chemical interaction and polymer coating. FT-IR result clearly confirmed the interaction between f-SWNT and COS. The effective drug release was monitored against cervical cancer (HeLa) cells and Breast Cancer (MCF-7) cells and it was found that all the three drug delivery systems showed significant cytotoxicity. f-SWNTs-COS-GTX-p53 delivery vehicle and its effective cytotoxicity on HeLa cells was further checked with fluorescent activated cell sorter analysis. Our results suggest that the f-SWNTs-COS-GTX-p53 is the most effective delivery vehicle with a controlled release and enhanced cytotoxicity rendered through apoptosis in human cervical cancer (HeLa) cells. These systems can further be used for the delivery of other commercially available anti cancer drugs as well.

Antimicrobial Activity of Chitosan-Carbon Nanotube Hydrogels.

In the present study, we have prepared chitosan-carbon nanotube (Chitosan-CNT) hydrogels by the freeze-lyophilization method and examined their antimicrobial activity. Different concentrations of CNT were used in the preparation of Chitosan-CNT hydrogels. These differently concentrated CNT hydrogels were chemically characterized using Fourier Transform-Infrared Spectroscopy, Scanning Electron Microscopy and Optical microscopy. The porosity of the hydrogels were found to be >94%. Dispersion of chitosan was observed in the CNT matrix by normal photography and optical microscopy. The addition of CNT in the composite scaffold significantly reduced the water uptake ability. In order to evaluate antimicrobial activity, the serial dilution method was used towards Staphylococcus aureus, Escherichia coli and Candida tropicalis. The composite Chitosan-CNT hydrogel showed greater antimicrobial activity with increasing CNT concentration, suggesting that Chitosan-CNT hydrogel scaffold will be a promising biomaterial in biomedical applications.

In vivo study of chitosan-natural nano hydroxyapatite scaffolds for bone tissue regeneration.

Significant development has been achieved with bioceramics and biopolymer scaffolds in the construction of artificial bone. In the present study, we have developed and compared chitosan-micro hydroxyapatite (chitosan-mHA) and chitosan-nano hydroxyapatite (chitosan-nHA) scaffolds as bone graft substitutes. The biocompatibility and cell proliferation of the prepared scaffolds were checked with preosteoblast (MC3T3-E1) cells. Total Volume (TV), bone volume (BV), bone surface (BS), trabecular thickness (Tb.Th), trabecular number (Tb.N) and trabecular separation (Tb.Sp) were found to be higher in chitosan-nHA than chitosan-mHA scaffold. Hence, we suggest that chitosan-nHA scaffold could be a promising biomaterial for bone tissue engineering.