Fabrication and Characterization of Poly (vinyl alcohol) and Chitosan Oligosaccharide-Based Blend Films

Flaxseed Mucilage/Hydroxypropyl Methylcellulose and Sodium Alginate/Polyvinyl Alcohol Composite Bilayer Film as a Promising Drug Carrier for Periodontal Treatment

Objectives

The present study focused on the formulation of mucoadhesive bilayer composite films for the treatment of periodontitis and evaluation of their physicochemical properties.

Materials and Methods

The solvent casting technique was used to prepare films. The primary layer (D) was prepared with flaxseed and hydroxypropyl methylcellulose composite to sustain the release of doxycycline hyclate. The second layer (S) comprised sodium alginate and polyvinyl alcohol composite for faster release of clove oil. Both layers were combined to generate the bilayer film (B). All formulations were characterized further to obtain an optimized formulation.

Results

Attenuated total reflection-Fourier transform infrared radiation results showed intactness of drug and clove oil in the presence of excipients. The pH of the films was compatible with the periodontal cavity and the thickness was suitable for inserting into the cavity. The immediate release layer showed faster disintegration and swelling. The content of clove oil was above 80%. The rate of swelling of the primary layer was slow and drug content complied with the United States Pharmacopoeia. Scanning electron microscope analysis revealed intact, non-porous and smooth films. Films exhibited better mechanical strength and bioadhesiveness. Clove oil was released from the immediate release layer within 10 min, and doxycycline hyclate release was retarded to a minimum of up to 8 h in the primary layer as well as the bilayer. Formulation also had a significant effect on both Escherichia coli and Staphylococcus aureus.

Conclusion

In the current study, bilayers were successfully prepared and characterized. The optimized formulation can be effectively used for the treatment of periodontitis.

Nanocrystalline cellulose as a reinforcing agent for poly (vinyl alcohol)/ gellan-gum-based composite film for moxifloxacin ocular delivery

Nanocrystalline cellulose (NCC) is a star material in drug delivery applications due to its good biocompatibility, large specific surface area, high tensile strength (TS), and high hydrophilicity. Poly(Vinyl Alcohol)/Gellan-gum-based innovative composite film has been prepared using nanocrystalline cellulose (PVA/GG/NCC) as a strengthening agent for ocular delivery of moxifloxacin (MOX) via solvent casting method. Impedance analysis was studied using the capacitive sensing technique for examining new capacitance nature of the nanocomposite MOX film. Antimicrobial properties of films were evaluated using Pseudomonas aeruginosa and Staphylococcus aureus as gram-negative and gram-positive bacteria respectively by disc diffusion technique. XRD revealed the characteristic peak of NCC and the amorphous form of the drug. Sustained in vitro release and enhanced corneal permeation of drug were noticed in the presence of NCC. Polymer matrix enhanced the mechanical properties (tensile strength 22.05 to 28.41 MPa) and impedance behavior (resistance 59.23 to 213.23 Ω) in the film due to the presence of NCC rather than its absence (16.78 MPa and 39.03 Ω respectively). Occurrence of NCC brought about good antimicrobial behavior (both gram-positive and gram-negative) of the film. NCC incorporated poly(vinyl alcohol)/gellan-gum-based composite film exhibited increased mechanical properties and impedance behavior for improved ocular delivery of moxifloxacin.

Development of microemulgel formulations with varied permeation enhancers for transungual delivery of luliconazole in onychomycosis management

Luliconazole-loaded microemulgels containing different permeation enhancers were formulated for transungual drug delivery for the management of onychomycosis, onychomycosis, which affects nails. The physicochemical properties like droplet size, zeta potential, pH, viscosity, spreadability, extrudability, oil binding capacity, drug content, and microscopic study were evaluated. The Pseudo-ternary phase diagram was constructed for the formulation of microemulsions (MEs) by keeping the Km ratio constant at 3:1 and characterized for clarity, mean droplet size, zeta potential, viscosity, pH, transmittance, refractive index, and stability. The ME mean droplet size and zeta potential were found in the range of 38.78 to 171.4 nm, and 0.00 to - 6.6 mV, respectively. Prepared MEs were converted into microemulgel by adding a 2.5% gelling agent (Carbapol 934) in the external phase, and a drug release study was conducted. Formulation E3 showed better drug release and was chosen as the control. Four different penetration enhancers were added separately within E3 and further evaluated for pH, viscosity, spreadability, extrudability, oil binding capacity, drug content, microscopic study, Compatibility study, XRD, and DSC. A favorable docking score was observed between luliconazole and Lanosterol 14-alpha-demethylase. In-vitro cumulative drug release at the end of 24 h from E3-SS, containing sodium sulfide as a penetration enhancer, was found to be 94.70% and was 2 times more than the control formulation. Ex-vivo transungual permeation studies through cutting nail clippings were found to be in the range of 28.18 - 36.52 µg/mm2. The microemulgels tagged as E3, E3-SS, and E3-SL showed a significant zone of inhibition against Candida albicans and Aspergillus fumigatus as compared to the marketed formulation.

Towards personalized drug delivery via semi-solid extrusion: Exploring poly(vinyl alcohol-co-vinyl acetate) copolymers for hydrochlorothiazide-loaded films

The increasing need for personalized drug delivery requires developing systems with tailorable properties. The copolymer poly(vinyl alcohol-co-vinyl acetate) (PVA/PVAc) allows for adjusting the monomer ratio. This study explored the effect of vinyl alcohol (VA) and vinyl acetate (VAc) monomer ratio on the properties of hydrochlorothiazide (HCT) films. Five copolymers with different VA/VAc ratios were selected and characterized. Semi-solid extrusion was employed as a method for the preparation of HCT-PVA/PVAc films to address the challenges of HCT´s low water solubility, high melting point, and low permeability. All copolymers were suitable for semi-solid extrusion, however, the mechanical properties of films with higher VA proportions were more suitable. The drug was found to be homogeneously distributed on a micrometer level throughout the prepared films. It was found that using different monomer ratios in the copolymer allows for drug release tuning - higher VA proportions showed an increased rate of drug release. Experiments through HT29-MTX cell monolayers revealed differences in HCT permeability between the different formulations. In addition, no cytotoxicity was observed for the tested formulations. The results highlight the effect of monomer ratio on film properties, providing valuable guidance for formulators in selecting PVA/PVAc copolymers for achieving desired high-quality films. In addition, varying the monomer ratio allows tuning of the film properties, and can be applied for personalization, with flexible-dose adjustment and design of appealing shapes of the pharmaceutics, not least attractive for pediatric drug delivery.

A novel biomimetic nanofibrous cardiac tissue engineering scaffold with adjustable mechanical and electrical properties based on poly(glycerol sebacate) and polyaniline

Biomaterial tissue engineering scaffolds play a critical role in providing mechanical support, promoting cells growth and proliferation. However, due to the insulation and inappropriate stiffness of most biomaterials, there is an unmet need to engineer a biomimetic nanofibrous cardiac tissue engineering scaffold with tailorable mechanical and electrical properties. Here, we demonstrate for the first time the feasibility to generate a novel type of biocompatible fibrous scaffolds by blending elastic poly(glycerol sebacate) (PGS) and conductive polyaniline (PANI) with the help of a nontoxic carrier polymer, poly (vinyl alcohol) (PVA). Aligned and random PGS/PANI scaffolds are successfully obtained after electrospinning, cross-linking, water and ethanol wash. Incorporating of different concentrations of PANI into PGS fibers, the fibrous sheets show enhanced conductivity and slower degradation rates while maintaining the favorable hemocompatibility. The elastic modulus of the PGS/PANI scaffolds is in the range of 0.65-2.18 MPa under wet conditions, which is similar to that of natural myocardium. All of these fibrous mats show good cell viability and were able to promote adhesion and proliferation of H9c2 cells. Furthermore, the in vivo host responses of both random and aligned scaffolds confirm their good biocompatibility. Therefore, these PGS/PANI scaffolds have great potential for cardiac tissue engineering.

Application of Coating Chitosan Derivatives (N,O-Carboxymethyl Chitosan/Chitosan Oligomer Saccharide) in Combination with Polyvinyl Alcohol Solutions to Preserve Fresh Ngoc Linh Ginseng Quality

The postharvest preservation of Ngoc Linh ginseng (NL ginseng) is essential to retain its quality and sensory values for prolonged storage. In this study, the efficacy of NL ginseng preservation by coating chitosan derivatives in combination with polyvinyl alcohol (PVA) solutions was investigated under refrigeration conditions (~3 °C; ~40% RH) for 56 days. The effect of the chitosan-based solutions, including N,O-carboxymethyl chitosan (NOCC), chitosan oligomer saccharide (COS), or chitosan (CS), and the blend solutions (NOCC-PVA or COS-PVA) on the coated NL ginsengs was observed during storage. The pH values, viscosity, and film-forming capability of the coating solutions were determined, while the visual appearance, morphology, and mechanical properties of the films formed on glass substrates as a ginseng model for coating were also observed. The appearance, skin lightness, weight loss, sensory evaluation, total saponin content (TSC), total polyphenol content (TPC), and total antioxidant capacity (TAC) of the coated NL ginsengs were evaluated. The findings showed that the observed values of the coated NL ginsengs were better than those of the non-coated samples, with the exception of the COS-coated samples, which had completely negative results. Furthermore, the NOCC-PVA solution exhibited a better preservation effect compared with the COS-PVA one based on the observed indices, except for TPC and TAC, which were not impacted by the coating. Notably, the optimal preservation time was determined to be 35 days. This study presents promising preservation technology using the coating solution of NOCC-PVA, harnessing the synergistic effect of pH 7.4 and the form-firming capacity, to maintain the shelf life, medicinal content, and sensory attributes of NL ginseng.

Composition Effects on the Morphology of PVA/Chitosan Electrospun Nanofibers

Since the SARS-CoV-2 pandemic, the interest in applying nanofibers t air filtration and personal protective equipment has grown significantly. Due to their morphological and structural properties, nanofibers have potential applications for air filtration in masks and air filters. However, most nanofiber membrane materials used for these purposes are generally non-degradable materials, which can contribute to the disposal of plastic waste into the environment. Hence, this work aims to produce polyvinyl alcohol (PVA) and chitosan (CS) biodegradable nanofibers with controlled morphology and structure via electrospinning. An experimental design was used to investigate the effects of the PVA|CS ratio and concentration on the properties of the electrospinning compositions and electrospun nanofiber mat. The electrospinning parameters were constant for all experiments: Voltage of 20 kV, a feed rate of 0.5 mL·h−1, and a distance of 10 cm between the needle and a drum collector. CS proved to be an efficient adjuvant to the PVA’s electrospinning, obtaining a wide range of nanofiber diameters. Furthermore, 6.0% PVA and 1% CS were the best compositions after optimization with the response surface methodology, with a mean fiber diameter of 204 nm. The addition of biocide agents using the optimized condition was also investigated, using surfactants, citric acid, and pure and encapsulated essential oils of Lippia sidoides. Pure oil improved the material without enlarging the nanofiber sizes compared to the other additives. The nanofiber membranes produced have the potential to be used in air filtration or wound-dressing applications where biocidal activity is needed.

Essential Oils as Antimicrobial Active Substances in Wound Dressings

Wound dressings for skin lesions, such as bedsores or pressure ulcers, are widely used for many patients, both during hospitalization and in subsequent treatment at home. To improve the treatment and shorten the healing time and, therefore, the cost, numerous types of wound dressings have been developed by manufacturers. Considering certain inconveniences related to the intolerance of some patients to antibiotics and the antimicrobial, antioxidant, and curative properties of certain essential oils, we conducted research by incorporating these oils, based on polyvinyl alcohol/ polyvinyl pyrrolidone (PVA/PVP) biopolymers, into dressings. The objective of this study was to study the potential of a polymeric matrix for wound healing, with polyvinyl alcohol as the main material and polyvinyl pyrrolidone and hydroxypropyl methylcellulose (HPMC) as secondary materials, together with additives (plasticizers poly(ethylene glycol) (PEG) and glycerol), stabilizers (Zn stearate), antioxidants (vitamin A and vitamin E), and four types of essential oils (fennel, peppermint, pine, and thyme essential oils). For all the studied samples, the combining compatibility, antimicrobial, and cytotoxicity properties were investigated. The obtained results demonstrated a uniform morphology for almost all the samples and adequate barrier properties for contact with suppurating wounds. The results show that the obtained samples containing essential oils have a good inhibitory effect on, or antimicrobial properties against, Staphylococcus aureus ATCC 25923, Enterococcus faecalis ATCC 29212, Escherichia coli ATCC 25922, Pseudomonas aeruginosa ATCC 27853, and Candida albicans ATCC 10231. The MTT assay showed that the tested samples were not toxic and did not lead to cell death. The results showed that the essential oils used provide an effective solution as active substances in wound dressings.

Date-Palm-Derived Cellulose Nanocrystals as Reinforcing Agents for Poly(vinyl alcohol)/Guar-Gum-Based Phase-Separated Composite Films

The current study delineates the use of date-palm-derived cellulose nanocrystals (dp-CNCs) as reinforcing agents. dp-CNCs were incorporated in varying amounts to poly(vinyl alcohol)/guar-gum-based phase-separated composite films. The films were prepared by using the solution casting method, which employed glutaraldehyde as the crosslinking agent. Subsequently, the films were characterized by bright field and polarizing microscopy, UV-Vis spectroscopy, FTIR spectroscopy, and mechanical study. The microscopic techniques suggested that phase-separated films were formed, whose microstructure could be tailored by incorporating dp-CNCs. At higher levels of dp-CNC content, microcracks could be observed in the films. The transparency of the phase-separated films was not significantly altered when the dp-CNC content was on the lower side. FTIR spectroscopy suggested the presence of hydrogen bonding within the phase-separated films. dp-CNCs showed reinforcing effects at the lowest amount, whereas the mechanical properties of the films were compromised at higher dp-CNC content. Moxifloxacin was included in the films to determine the capability of the films as a drug delivery vehicle. It was found that the release of the drug could be tailored by altering the dp-CNC content within the phase-separated films. In gist, the developed dp-CNC-loaded poly(vinyl alcohol)/guar-gum-based phase-separated composite films could be explored as a drug delivery vehicle.

Inherent and Composite Hydrogels as Promising Materials to Limit Antimicrobial Resistance

Antibiotic resistance has increased significantly in the recent years, and has become a global problem for human health and the environment. As a result, several technologies for the controlling of health-care associated infections have been developed over the years. Thus, the most recent findings in hydrogel fabrication, particularly antimicrobial hydrogels, could offer valuable solutions for these biomedical challenges. In this review, we discuss the most promising strategies in the development of antimicrobial hydrogels and the application of hydrogels in the treatment of microbial infections. The latest advances in the development of inherently and composite antimicrobial hydrogels will be discussed, as well as hydrogels as carriers of antimicrobials, with a focus on antibiotics, metal nanoparticles, antimicrobial peptides, and biological extracts. The emergence of CRISR-Cas9 technology for removing the antimicrobial resistance has led the necessity of new and performant carriers for delivery of the CRISPR-Cas9 system. Different delivery systems, such as composite hydrogels and many types of nanoparticles, attracted a great deal of attention and will be also discussed in this review.