In vitro biocompatibility analysis of functionalized poly(vinyl chloride)/layered double hydroxide nanocomposites

Designing a contact lens with atropine base using a microemulsion technique

PURPOSE

Myopia or near-sightedness is a global vision problem. Atropine eye drops and myopia-controlling contact lenses can help to slow down its progression, but neither is sufficient alone. The present research work was conducted to design a contact lens embedded with an atropine base within a microemulsion system. The goal was to improve the stability of atropine base and facilitate its release from the lens, preventing the rapid clearance observed with atropine eye drops.

METHODS

Two microemulsions, one with a pH of 7.4 and the other with a pH of 6.5, were developed using the surfactant D-alpha-tocopherol polyethylene glycol 1000 succinate (TPGS), the co-surfactant polyethylene glycol 400 (PEG 400), the emulsifier Capmul MCM C8, atropine base, and phosphate-buffered saline (PBS). The microemulsions were kept at room temperature (21 °C) and the amount of the atropine base in microemulsions were checked periodically over one year using reverse-phase High Performance Liquid Chromatography (RPHPLC) to determine its stability. The globule size of the formulations was measured using a zetasizer. MiSight contact lenses were soaked in the atropine base microemulsion formulations for 24 h, and the amount of atropine base loaded into contact lenses and released in PBS was measured by a RPHPLC. ISO 10993-5 guidelines were used to measure the in vitro cytotoxicity of atropine base loaded contact lenses.

RESULTS

The atropine base was more stable in the microemulsion at pH 6.5 (ME 6.5) with less than 4 % degradation, compared to a 10 % degradation at pH 7.4 (ME 7.4). The globule sizes of the microemulsions ranged between 17-21 nm. MiSight lenses absorbed4.25 ± 1.67 µg atropine base from ME 6.5, with the majority of the atropine base (3.52 ± 0.03 µg) released within 2 h. However, elutes from atropine base loaded contact lenses were toxic to human corneal epithelial cells (HCECs), reducing cell viability to less than 5 % after 24 h.

CONCLUSIONS

While the microemulsions were stable and the contact lenses released sufficient amounts of atropine base, future studies are needed to address the toxicity issue.

Chemical and physical modification of graphene oxide nano-sheets using casein, Zn-Al layered double hydroxide, alginate hydrogel, and magnetic nanoparticles for biomedical applications

In our study, we developed a novel nanobiocomposite using graphene oxide (GO), casein (Cas), ZnAl layered double hydroxide (LDH), sodium alginate (Alg), and Fe3O4 magnetic nanoparticles. To synthesize the GO, we used a modified Hummer's method and then covalently functionalized its surface with Cas protein. The functionalized GO was combined with as-synthesized ZnAl LDH, and the composite was conjugated with alginate hydrogel through the gelation process. Finally, we magnetized the nanobiocomposite using in-situ magnetization. The nanobiocomposite was comprehensively characterized using FT-IR, FE-SEM, EDX, and XRD. Its biological potential was assessed through cell viability, hemolysis, and anti-biofilm assays, as well as its application in hyperthermia. The MTT assay showed high cell viability percentages for Hu02 cells after 24, 48, and 72 h of incubation. The nanobiocomposite had a hemolytic effect lower than 3.84 %, and the measured bacterial growth inhibition percentages of E. coli and S. aureus bacteria in the presence of the nanobiocomposite were 52.18 % and 55.72 %, respectively. At a concentration of 1 mg.mL-1 and a frequency of 400 kHz, the nanocomposite exhibits a remarkable specific absorption rate (SAR) of 67.04 W.g-1, showcasing its promising prospects in hyperthermia applications.

Eco-friendly bio-nanocomposites: pioneering sustainable biomedical advancements in engineering

Biomedical nanocomposites, which are an upcoming breed of mischievous materials, have ushered in a new dimension in the healthcare sector. Incorporating these materials tends to boost features this component already possesses and give might to things these components could not withstand alone. The biopolymer, which carries the nanoparticles, can simultaneously improve the composite's stiffness and biological characteristics, and vice versa. This increases the options of the composite and the number of times it can be used. The bio-nanocomposites and nanoparticles enable the ecocompatibility of the medicine in their biodegradability, and they, in this way, have ecological sustainability. The outcome is the improved properties of medicine and its associated positive impact on the environment. They have broad applications in antimicrobial agents, drug carriers, tissue regeneration, wound care, dentistry, bioimaging, and bone filler, among others. The dissertation on the elements of bio-nanocomposites emphasizes production techniques, their diverse applications in medicine, match-up issues, and future-boasting prospects in the bio-nanocomposites field. Through the utilization of such materials, scientists can develop more suitable for the environment and healthy biomedical solutions, and world healthcare in this way improves as well.

Blood Compatibility of Drug-Inorganic Hybrid in Human Blood: Red Blood Cell Hitchhiking and Soft Protein Corona

A drug-delivery system consisting of an inorganic host-layered double hydroxide (LDH)-and an anticancer drug-methotrexate (MTX)-was prepared via the intercalation route (MTX-LDH), and its hematocompatibility was investigated. Hemolysis, a red blood cell counting assay, and optical microscopy revealed that the MTX-LDH had no harmful toxic effect on blood cells. Both scanning electron microscopy and atomic force microscopy exhibited that the MTX-LDH particles softly landed on the concave part inred blood cells without serious morphological changes of the cells. The time-dependent change in the surface charge and hydrodynamic radius of MTX-LDH in the plasma condition demonstrated that the proteins can be gently adsorbed on the MTX-LDH particles, possibly through protein corona, giving rise to good colloidal stability. The fluorescence quenching assay was carried out to monitor the interaction between MTX-LDH and plasma protein, and the result showed that the MTX-LDH had less dynamic interaction with protein compared with MTX alone, due to the capsule moiety of the LDH host. It was verified by a quartz crystal microbalance assay that the surface interaction between MTX-LDH and protein was reversible and reproducible, and the type of protein corona was a soft one, having flexibility toward the biological environment.

Modification of Poly(vinyl chloride) with Bio-Based Cassia Oil to Improve Thermo-Mechanical and Antimicrobial Properties

The purpose of this study was to modify plasticised PVC to obtain a material with antimicrobial properties and selected mechanical properties. Natural cassia oil (CO) was used to modify plasticised PVC materials. The modified material was produced by extrusion. The introduced modifier had a maximum concentration of 20 phr. Rheological and mechanical properties were evaluated, and the glass transition temperature was determined. The antioxidant and antimicrobial activity of the agar diffusion method was investigated by analysing the growth inhibition zones against Enterococcus faecalis and Listeria monocytogenes. A favourable effect of the cassia oil content on the increase in antioxidant activity of the developed polymeric materials was found with an increase in the modifier content and the duration of action (30 days). The largest growth restriction zones were observed for L. monocytogenes, i.e., they showed the highest sensitivity to the modified material. The simultaneous decrease in modulus of elasticity, increase in elongation at break, and decrease in T_g indicate that the modifier has a plasticising effect on PVC. The developed material may find application as an active and/or functional material, especially as an emitter of antimicrobial agents, in the packaging used to store minimally processed food.

A Preliminary Cytotoxicity Study of Fagonia arabica against Breast (MCF-7), Oral (KB-3-1), and Lung Cancer (A-549) Cell Lines: A Study Supported by Molecular Marker Analysis Using Dual Staining Dyes

Aim: The objective of this research is to present a phytochemical profile of Fagonia arabica and to investigate the cytotoxic potential of its extracts against breast, oral, and lung cancer cell lines using MTT assay and dual staining-based mechanistic analysis. Methods: The progressive extraction of F. arabica was carried out using the Soxhlet extraction technique. The total phenolic and flavonoid content was calculated as part of the phytochemical profiling performed using GCMS and LCMS methods. The MTT assay was utilized to assess the cytotoxicity against normal L929 cells, as well as malignant A549, MCF-7, and KB-3-1cell lines. Results: The phenolic compounds and flavonoids were the two main elements of the F. arabica methanolic extract, with 1323 µg GAE/g of dry weight and 523.07 µg QE/g of dry weight, respectively. The presence of the functional phytochemicals was verified by GCMS and LCMS analyses. Toxicity testing on the L929 cell line found that the F. arabica methanol extract was the least harmful, with the highest IC50 (296.11 µg/mL). The MTT assay for cell viability against MCF-7 and KB-3-1 yielded significant results, with IC50 values of 135.02 µg/mL and 195.21 µg/mL, respectively. The aqueous extract exhibited significant cytotoxicity against the A549 cell lines (IC50 116.06 µg/mL). The molecular marker analyses using dual staining revealed that the methanolic extract successfully triggered apoptosis in the different cancer cells tested. Conclusion: The present data suggest that the methanol extract of F. arabica has substantial cytotoxic action against lung, breast, and oral cancer cell lines. Thus, F. Arabica would be a promising source of anticancer medicines, warranting more research to identify the lead molecules with anticancer properties.

Surface modification of two-dimensional layered double hydroxide nanoparticles with biopolymers for biomedical applications

Layered double hydroxides (LDHs) are appealing nanomaterials for (bio)medical applications and their potential is threefold. One can gain advantage of the structure of LDH frame (i.e., layered morphology), anion exchanging property towards drugs with acidic character and tendency for facile surface modification with biopolymers. This review focuses on the third aspect, as it is necessary to evaluate the advantages of polymer adsorption on LDH surfaces. Beside the short discussion on fundamental and structural features of LDHs, LDH-biopolymer interactions will be classified in terms of the effect on the colloidal stability of the dispersions. Thereafter, an overview on the biocompatibility and biomedical applications of LDH-biopolymer composite materials will be given. Finally, the advances made in the field will be summarized and future research directions will be suggested.

Anticoagulation polyvinyl chloride extracorporeal circulation catheters for heparin-free treatment

Extracorporeal circulation (ECC) catheters have potential to be blood compatible and could be used to prevent thrombotic occlusion. Here, we produced heparin-mimicking anticoagulation PVC tubing on a large scale by synthesizing a heparin-mimicking polymer (HMP) and co-extruding. The PVC@HMP catheter was evaluated using whole human blood in vitro, which indicated it could prevent plasma protein attachment, reduce platelet adhesion and activation, and inhibit coagulation factors (XII, XI, IX, and VIII). Moreover, the anticoagulation PVC tubing was assembled into extracorporeal circulation with a New Zealand rabbit model, manifesting excellent real-time antithrombogenic properties without systemic heparin anticoagulation in vivo. The rapid recovery of coagulation factors after operation further confirmed its superiority over heparin, which would not completely inactivate the activity of those coagulation factors (XII, XI, IX and VIII). In addition, the PVC@HMP-1 catheters remain patent after being implanted in rats for 28 days without apparent inflammation and mortality complications. The anticoagulation PVC tubes could be used to construct various systemic and integrative anticlotting biomedical devices, which would dramatically reduce the introduction of heparin into blood circulation, thus preventing side effects and promoting the development of heparin-free treatment.

Layered double hydroxide-based nanocomposite scaffolds in tissue engineering applications

Layered double hydroxides (LDHs), when incorporated into biomaterials, provide a tunable composition, controllable particle size, anion exchange capacity, pH-sensitive solubility, high-drug loading efficiency, efficient gene and drug delivery, controlled release and effective intracellular uptake, natural biodegradability in an acidic medium, and negligible toxicity. In this review, we study potential applications of LDH-based nanocomposite scaffolds for tissue engineering. We address how LDHs provide new solutions for nanostructure stability and enhance in vivo studies' success.

Cytotoxic and apoptotic inducing activity of Amoora rohituka leaf extracts in human breast cancer cells

BACKGROUND

Amoora rohituka is described in Ayurveda, an Indian traditional system of medicine for management of disorders of blood, diseases of eye, helminthiasis disease, ulcer, liver disorders and splenomegaly. However, the leaves were not reported to have anticancer properties till date.

OBJECTIVE

This study was carried out to evaluate the cytotoxic potential of leaf extracts of Amoora rohituka.

MATERIALS AND METHODS

The leaves powder was macerated in petroleum ether, ethyl acetate and methanol and evaluated their anticancer activities in vitro. The phytochemical constituents of the active (ethyl acetate) extract were screened by FTIR analysis and phytochemical screening methods.

RESULTS

The ethyl acetate extract (RLEA) showed the presence of alkaloids, flavonoids, steroids, tannins, saponins and terpenoids. The RLEA exhibited high cytotoxic effect against human breast cancer cells, MCF-7 (IC50 = 9.81 μg/mL) and induced apoptosis by altering nuclear morphology and DNA laddering. Wound healing assays explained the potency of extract to decrease the cell migration.

CONCLUSION

The extract of Amoora rohituka leaves exhibited anticancer activity with less toxicity and it could be used for development of alternative drugs in the treatment of human breast cancer.

Biogenic green synthesis of MgO nanoparticles using Saussurea costus biomasses for a comprehensive detection of their antimicrobial, cytotoxicity against MCF-7 breast cancer cells and photocatalysis potentials

Distinct morphological MgO nanoparticles (MgONPs) were synthesized using biomasses of Saussurea costus roots. The biomass of two varieties of Saussurea costus (Qustal hindi and Qustal bahri) were used in the green synthesis of MgONPs. The physical and chemical features of nanoparticles were confirmed by spectroscopic and microscopic techniques. The surface morphology of the obtained nanoparticles was detected at different magnifications by SEM and TEM microscopy and the size of nanoparticles were found to be 30 and 34 nm for Qustal hindi and Qustal bahri, respectively. The antimicrobial activity of the prepared MgONPs was screened against six pathogenic strains. The synthesized nanoparticles by Qustal bahri biomass exerted significant inhibition zones 15, 16, 18, 17, 14, and 10 mm against E. coli, P. aeruginosa, C. tropicalis and C. glabrata, S. aureus and B. subtilis as compared to those from Qustal hindi 12, 8 and 17 mm against B. subtilis, E. coli and C. tropicalis, respectively. MgONPs showed a potential cytotoxicity effect against MCF-7 breast cancer cell lines. Cellular investigations of MgONPs revealed that the prepared nanoparticles by Qustal bahri exhibited high cytotoxicity against MCF-7 cancer cell lines. IC50 values in MCF-7 cells were found to be 67.3% and 52.1% for MgONPs of Saussurea costus biomasses, respectively. Also, the photocatalytic activity of MgONPs of each Saussurea costus variety was comparatively studied. They exhibited an enhanced photocatalytic degradation of methylene blue after UV irradiation for 1 h as 92% and 59% for those prepared by Qustal bahri and Qustal hindi, respectively. Outcome of results revealed that the biosynthesized MgONPs showed promising biomedical potentials.

Graphene oxide/alginate/silk fibroin composite as a novel bionanostructure with improved blood compatibility, less toxicity and enhanced mechanical properties

For biomedical applications, the design and synthesis of biocompatible nanostructures, are considered as critical challenges. In this study, graphene oxide (GO) was covalently modified by natural sodium alginate (Alg) polymer. By adding silk fibroin (SF) to this nanostructure, a hybrid nanobiocomposite (GO/Alg/SF) was resulted and its unique features were determined using FT-IR, EDX, FE-SEM, XRD and TG analyses. Because of using less toxic and high biocompatible materials, specific biological results were achieved. The cell viability of this novel nanostructure was 89.2 % and its hemolytic effect was less than 6% while the highest concentration (1000 μg/mL) of this nanostructure was chosen for these purposes. Also, high mechanical properties including the compressive strength (0.87 ± 0.034 (MPa)) and the compressive modulus (2.25 ± 0.091 (MPa)) were exposed. This nanostructure can be considered as a scaffold for wound dressing applications due to the mentioned properties.

Morphology, Thermal Stability, and Flammability Properties of Polymer-Layered Double Hydroxide (LDH) Nanocomposites: A Review

The utilization of layered nanofillers in polymer matrix, as reinforcement, has attracted great interest in the 21st century. This can be attributed to the high aspect ratios of the nanofillers and the attendant substantial improvement in different properties (i.e., increased flammability resistance, improved modulus and impact strength, as well as improved barrier properties) of the resultant nanocomposite when compared to the neat polymer matrix. Amongst the well-known layered nanofillers, layered inorganic materials, in the form of LDHs, have been given the most attention. LDH nanofillers have been employed in different polymers due to their flexibility in chemical composition as well as an adjustable charge density, which permits numerous interactions with the host polymer matrices. One of the most important features of LDHs is their ability to act as flame-retardant materials because of their endothermic decomposition. This review paper gives detailed information on the: preparation methods, morphology, flammability, and barrier properties as well as thermal stability of LDH/polymer nanocomposites.

Design and identification of poly(vinyl chloride)/layered double hydroxide@MnO2 nanocomposite films and evaluation of the methyl orange uptake: linear and non-linear isotherm and kinetic adsorption models

In this work, an adsorbent based on poly(vinyl chloride) (PVC) for the removal of methyl orange (MO) dye is proposed.

Characterization and evaluation of mycosterol secreted from endophytic strain of Gymnema sylvestre for inhibition of α-glucosidase activity

Endophytic fungi produce various types of chemicals for establishment of niche within the host plant. Due to symbiotic association, they secrete pharmaceutically important bioactive compounds and enzyme inhibitors. In this research article, we have explored the potent α-glucosidse inhibitor (AGI) produced from Fusarium equiseti recovered from the leaf of Gymnema sylvestre through bioassay-guided fraction. This study investigated the biodiversity, phylogeny, antioxidant activity and α-glucosidse inhibition of endophytic fungi isolated from Gymnema sylvestre. A total of 32 isolates obtained were grouped into 16 genera, according to their morphology of colony and spores. A high biodiversity of endophytic fungi were observed in G. sylvestre with diversity indices. Endophytic fungal strain Fusarium equiseti was identified through DNA sequencing and the sequence was deposited in GenBank database (https://ncbi.nim.nih.gov) with acession number: MF403109. The characterization of potent compound was done by FTIR, LC-ESI-MS and NMR spectroscopic analysis with IUPAC name 17-(5-ethyl-6-methylheptan-2-yl)-10,13-dimethyl-2,3,4,7,8,9,10,11,12,13,14,15,16,17-tetradecahydro-1H-cyclopenta[a] phenanthren-3-ol. The isolated bioactive compound showed significant α-amylase and α-glucosidase inhibition activity with IC50 values, 4.22 ± 0.0005 µg/mL and 69.72 ± 0.001 µg/mL while IC50 values of acarbose was 5.75 ± 0.007 and 55.29 ± 0.0005 µg/mL respectively. This result is higher in comparison to other previous study. The enzyme kinetics study revealed that bioactive compound was competitive inhibitor for α-amylase and α-glucosidase. In-silico study showed that bioactive compound binds to the binding site of α-amylase, similar to that of acarbose but with higher affinity. The study highlights the importance of endophytic fungi as an alternative source of AGI (α-glucosidase inhibition) to control the diabetic condition in vitro.

Mg-Al-CO3 layered double hydroxide reinforced polymer inclusion membrane as an extractant phase for thin-film microextraction of cyanide from environmental water samples

In this paper, a flexible and efficient nano-reinforced polymer inclusion membrane (PIM) was fabricated and used for cyanide (CN^-) extraction from water samples. Aliquat 336 (a liquid anion exchanger) was embedded in poly(vinyl chloride) (PVC) support as the extractant. Mg-Al-CO₃ layered double hydroxide (LDH) with high surface area and anion exchange ability was applied to promote the extraction efficiency of PIM. A PIM comprising 56% PVC, 40% Aliquat 336, and 4% Mg-Al-CO₃ LDH showed the best extraction efficiency. A single beam ultraviolet-visible spectrophotometer was used for the detection of cyanide. Surface morphology of the PIM was studied by field emission scanning electron microscopy. The experimental parameters influencing the extraction process were investigated and optimized. The intra- and inter-day relative standard deviations at two different concentrations were in the range of 2.8-7.6%. The dynamic range of the method was in the range of 5-500 μg L^-1, and the detection limit was 1.4 μg L^-1. The LDH reinforced PIM showed proper characteristics for the extraction of cyanide from real water and wastewater samples with recoveries between 82 and 115%.