Kappa-Carrageenan/PVA Filmswith Antibacterial Properties: Part 1. Optimization of Preparation Conditions and Preliminary Drug Release Studies

Low-cost and eco-friendly PVA/carrageenan membrane to efficiently remove cationic dyes from water: Isotherms, kinetics, thermodynamics, and regeneration study

Methylene blue (MB), a common dye in the textile industry, has a multitude of detrimental consequences on humans and the environment. Accordingly, it is necessary to remove dyes from water to guarantee our health and sustainable ecosystem. In this study, we developed polyvinyl alcohol (PVA)-based hydrogel adsorbents with high adsorption capacity by adding three types of carrageenan (kappa, iota, and lambda) to remove MB from water. Thanks to the functional groups, the PVA/carrageenan membranes dramatically increased the removal efficiency (kappa, 98.8%; iota, 97.0%; lambda, 95.4%) compared to the pure PVA membrane (6.3%). Among the three types of PVA/carrageenan membranes, the PVA/kappa-carrageenan membrane exhibited the best adsorption capacity of 147.8 mg/g. This result implies that steric hindrance was considerably significant, given that kappa carrageenan has only one sulfate group in the repeating unit, whereas iota and lambda carrageenan composite PVA membranes possess two and three sulfate groups. Apart from the maximum adsorption capacity, this study addressed a variety of characteristics of PVA/carrageenan membranes such as the effects of initial MB concentration, kappa carrageenan weight percentage, contact time, adsorbent dosage, and temperature on the adsorption performance. In addition, the kinetic and thermodynamic studies were also carried out. Lastly, the reusability of the PVA/carrageenan membrane was verified by the 98% removal efficiency maintained after five adsorption-desorption cycles.

Evaluation of Opuntia-carrageenan superporous hydrogel (OPM-CRG SPH) as an effective biomaterial for drug release and tissue scaffold

The process of wound healing involves complex interplay of systems biology, dependent on coordination of various cell types, both intra and extracellular mechanisms, proteins, and signaling pathways. To enhance these interactions, drugs must be administered precisely and continuously, effectively regulating the intricate mechanisms involved in the body's response to injury. Controlled drug delivery systems (DDS) play a pivotal role in achieving this objective. A proficient DDS shields the wound from mechanical, oxidative, and enzymatic stress, against bacterial contamination ensuring an adequate oxygen supply while optimizing the localized and sustained delivery of drugs to target tissue. A pH-sensitive SPH was designed by blending two natural polysaccharides, Opuntia mucilage and carrageenan, using microwave irradiation and optimized according to swelling index at pH 1.2, 7.0, and 8.0 and % porosity. Optimized grade was analyzed for surface hydrophilicity-hydrophobicity using OCA. Analytical characterizations were performed using FTIR, TGA, XRD, DSC, reflecting semicrystalline behavior. Mechanical property confirmed adequate strength. In vitro drug release study with ciprofloxacin-HCL as model drug showed 97.8 % release within 10 h, fitting to the Korsmeyer-Peppas model following diffusion and erosion mechanism. In vitro antimicrobial, anti-inflammatory assays, zebrafish toxicity, and animal studies in mice with SPH concluded it as a novel biomaterial.

Development, Characterization, and Burn Wound-Healing Potential of Neomycin-Loaded Clay-Reinforced Nanofibers

Background: Skin wounds affect millions of individuals around the world, and their treatment is expensive. Objective: The purpose of this study was to make neomycin-loaded CG/PVA/PAN (NCPP) nanofibers to improve wound healing. Methods: The NCPP nanofibers were characterized by using thermogravimetric analysis (TGA), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy, and X-ray diffraction. Drug solubility, dissolution, swelling ratio, erosion, and antibacterial studies were performed. The in vivo wound healing study of nanofibers was performed in a rabbit model and was supported by % age wound closure and histopathology. Results: The results of SEM showed some sort of agglomeration on the surface of fibers, while TGA showed 10% more stability for drug-loaded nanofibers. The drug permeation study indicated that the formulation with 15% PVA showed a controlled release profile of the drug. The NCPP nanofibers had an appreciable water retention capability. The NCPP nanofibers showed appreciable antibacterial activity against Enterococcus faecalis (Gram-positive bacteria) and Klebsiella pneumonia (Gram-negative bacteria). The wound healing study showed the better healing properties of NCPP nanofibers within 15 days. Conclusion: The findings helped us to conclude that the NCPP nanofibers were successfully fabricated and found to have a promising role in infected wound healing.

Synthesis and Characterization of 𝒌-Carrageenan/PVA Nanocomposite Hydrogels in Combination with MgZnO Nanoparticles to Evaluate the Catechin Release

In the current study, nanocomposites were prepared by combining k-carrageenan, polyvinyl alcohol (PVA), and doped nanoparticles (Magnesium oxide) MgO, (Magnesium Zinc oxide) MgZnO 1%, MgZnO 3%, and MgZnO 5%. The nanoparticles were synthesized by a sol-gel method and mixed with a mixture of k-carrageenan/PVA (Ca/PVA) in various ratios. The structure of the composites was analyzed using thermogravimetric analysis (TGA), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FTIR). The Ca/PVA mixture was then mixed with nanoparticles and loaded with active ingredient, catechin. Scanning electron microscope (SEM) and texture analysis were performed to analyze the nanocomposites. Entrapment efficiency (EE%) and drug release studies confirmed that k-carrageenan/PVA/MgZnO 5% had the highest EE% at 81.58% and a drug release of 75.21% ± 0.94. The EE% of k-carrageenan/PVA/MgO was 55.21% and its drug release was 45%. This indicates that ZnO plays an effective role in the structure and performance of Ca/PVA composites. The SEM images of MgO composites show smoother surfaces compared to MgZnO composites. This may be one of the reasons for the increased EE% and drug release of MgZnO composites. The addition of ZnO to the composite structure can lead to the appearance of pores on the surface of the composite, increasing entrapment and drug release.

Furcellaran Surface Deposition and Its Potential in Biomedical Applications

Surface coatings of materials by polysaccharide polymers are an acknowledged strategy to modulate interfacial biocompatibility. Polysaccharides from various algal species represent an attractive source of structurally diverse compounds that have found application in the biomedical field. Furcellaran obtained from the red algae Furcellaria lumbricalis is a potential candidate for biomedical applications due to its gelation properties and mechanical strength. In the present study, immobilization of furcellaran onto polyethylene terephthalate surfaces by a multistep approach was studied. In this approach, N-allylmethylamine was grafted onto a functionalized polyethylene terephthalate (PET) surface via air plasma treatment. Furcellaran, as a bioactive agent, was anchored on such substrates. Surface characteristics were measured by means of contact angle measurements, X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM). Subsequently, samples were subjected to selected cell interaction assays, such as antibacterial activity, anticoagulant activity, fibroblasts and stem cell cytocompatibility, to investigate the Furcellaran potential in biomedical applications. Based on these results, furcellaran-coated PET films showed significantly improved embryonic stem cell (ESC) proliferation compared to the initial untreated material.

Expanding the Repertoire of Electrospinning: New and Emerging Biopolymers, Techniques, and Applications

Electrospinning has emerged as a versatile and accessible technology for fabricating polymer fibers, particularly for biological applications. Natural polymers or biopolymers (including synthetically derivatized natural polymers) represent a promising alternative to synthetic polymers, as materials for electrospinning. Many biopolymers are obtained from abundant renewable sources, are biodegradable, and possess inherent biological functions. This review surveys recent literature reporting new fibers produced from emerging biopolymers, highlighting recent developments in the use of sulfated polymers (including carrageenans and glycosaminoglycans), tannin derivatives (condensed and hydrolyzed tannins, tannic acid), modified collagen, and extracellular matrix extracts. The proposed advantages of these biopolymer-based fibers, focusing on their biomedical applications, are also discussed to highlight the use of new and emerging biopolymers (or new modifications to well-established ones) to enhance or achieve new properties for electrospun fiber materials.

Enhanced blood coagulation and antibacterial activities of carboxymethyl-kappa-carrageenan-containing nanofibers

Ideal wound dressings should be biocompatible, exhibit high antibacterial activity, and promote blood coagulation. To impart these imperative functions, carboxymethyl-kappa-carrageenan was incorporated into poly(vinyl alcohol) nanofibers (PVA-CMKC). The antibacterial activity of the nanofibers was evaluated. Adsorption of two important blood proteins, fibrinogen and albumin, was also assessed. The adhesion and activation of platelets, and the clotting of whole blood were evaluated to characterize the ability of the nanofibers to promote hemostasis. Adhesion and morphology of both Staphylococcus aureus and Pseudomonas aeruginosa were evaluated using fluorescence microscopy and scanning electron microscopy. CMKC-containing nanofibers demonstrated significant increases in platelet adhesion and activation, percentage of coagulation in whole blood clotting test and fibrinogen adsorption, compared to PVA nanofibers, showing blood coagulation activity. Incorporating CMKC also reduces adhesion and viability of S. aureus and P. aeruginosa bacteria after 24 h of incubation. PVA-CMKC nanofibers show potential application as dressings for wound healing applications.

Novel polymeric hydrogel composites: Synthesis, physicochemical, mechanical and biocompatible properties

In this research study, novel hydrogel composite films were constructed using different ratios of poly (vinyl alcohol) (PVA)/kappa-carrageenan (KC) (PVA90/KC10%, PVA80/KC20%, PVA70/KC30%, PVA60/KC40%) crosslinked with glutaraldehyde (0.025%) and investigated their physicochemical characteristics such as mechanical, thermal, morphological, swelling behaviour, and cell viability. SEM and FTIR revealed that surface morphology changed to heterogeneous and the presence of molecular interaction among the polymers. PVA90KC10 and PVA60KC40 exhibited smaller and larger pores on surface respectively. The change in the proportion of PVA and KC also triggered the tensile strength (Ts) of the film and the highest Ts observed were 21.60 MPa for PVA60KC40. Moreover, the thermal analysis showed three-phase degradation, and an increase in KC40 concentration results inversely proportional to a decrease in the rate of thermal degradation. Further, swelling and in-vitro biodegradation study confirmed the enhanced perseverance of water uptake for PVA60KC40 (286%) due to pores structure of the hydrogel film and PVA and KC alone degraded faster as compare to other films results suggested higher concentration of PVA90KC10 showed lower degradation rate and highest for PVA60KC40 about 6% and 22% respectively. Further, the cell viability was studied with MTT assay method by using NIH3T3 and HEK-293 cells for biocompatibility study revealed NIH3T3 cells were more biocompatible than HEK-293 and cell viability percent for PVA60KC40 showed the highest cell attachment about 99%. Overall corroborating data obtained from the study attested to the average swelling, appreciable mechanical characters, good interaction between molecules, and cell viability of the constructed PVA/KC hydrogel film, these all characters pave to be used as a potential template for biomedical applications such as tissue engineering and drug delivery.

Physically Crosslinked Poly (Vinyl Alcohol)/Kappa-Carrageenan Hydrogels: Structure and Applications

This paper discusses the structure morphology and the thermal and swelling behavior of physically crosslinked hydrogels, obtained from applying four successive freezing-thawing cycles to poly (vinyl alcohol) blended with various amounts of κ-carrageenan. The addition of carrageenan in a weight ratio of 0.5 determines a twofold increase in the swelling degree and the early diffusion coefficients of the hydrogels when immersed in distilled water, due to a decrease in the crystallinity of the polymer matrix. The diffusion of water into the polymer matrix could be considered as a relaxation-controlled transport (anomalous diffusion). The presence of the sulfate groups determines an increased affinity of the hydrogels towards crystal violet cationic dye. A maximum physisorption capacity of up to 121.4 mg/g for this dye was attained at equilibrium.