Enriched physicochemical and blood-compatible properties of nanofibrous polyurethane patch engrafted with juniper oil and titanium dioxide for cardiac tissue engineering

Cephradine drug release using electrospun chitosan nanofibers incorporated with halloysite nanoclay

The chitosan/polyvinyl alcohol/halloysite nanoclay (CS/PVA/HNC) loaded with cephradine drug electrospun nanofibers (NFs) were fabricated and characterized by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), thermogravimetric analysis (TGA) techniques. FTIR analysis confirmed the hydrogen bonding between the polymer chain and the developed siloxane linkages. SEM analysis revealed the formation of uniform NFs having beads free and smooth surface with an average diameter in 50–200 nm range. The thermal stability of the NFs was increased by increasing the HNC concentration. The antimicrobial activity was examined against Escherichia  coli and staphylococcus strains and the NFs revealed auspicious antimicrobial potential. The drug release was studied at pH 7.4 (in PBS) at 37 °C. The drug release analysis showed that 90% of the drug was released from NFs in 2 h and 40 min. Hence, the prepared NFs could be used as a potential drug carrier and release in a control manner for biomedical application.

Binding interaction of benzamide derivatives as inhibitors of DNA gyrase and Sec14p using Molegro Virtual Docker based on binding free energy

The docking simulation of benzamide derivatives as ligands and protein targets (DNA–gyrase) was performed and Sec14p binding mode interaction was predicted based on binding free energy analysis. Software Molegro Virtual Docking (MVD) was used to visualize the ligand–protein binding interactions. The results indicated the prevalence of steric or hydrophobic interactions among all the benzamide ligands besides hydrogen bonding or electrostatic interactions. The compounds B2, B4 against DNA gyrase, and compounds B3, B5 against Sec14p showed an uncompetitive pattern of inhibition as compared with the reference molecule. While compounds B1, B5 exhibited the best MolDock scores, i.e., −109.736 and −114.391 kcal/mol respectively for DNA gyrase, also compounds B1 and B2 against Sec14p displayed −100.105 and −119.451 kcal/mol sequentially. It was evident from the comparison of MolDock score for both the bacterial and fungal protein receptors that all the ligands were found to be more potent against DNA gyrase than Sec14p. However, only compound B2 with MolDock score −119.451 kcal/mol showed exceptional activity against Sec14p and was predicted to have potency as a lead compound to find a new anti-fungal therapeutic agent. Docking studies further highlighted the unique interactions such as tail-end hydrophobic rings of benzamide inhibitors with catalytically important amino acid residues, allowing flexibility in binding to both the receptors different from other inhibitors. These findings showed us that B1, B2 against Staphylococcus aureus and B5 against Saccharomyces cerevisiae could be leading compounds to discover new multidrug-resistant strains.

Self-Adhesion Conductive Sub-micron Fiber Cardiac Patch from Shape Memory Polymers to Promote Electrical Signal Transduction Function

Myocardial infarction (MI) constitutes the first cause of morbidity and mortality in our life, so using highly conductive and elastic materials to produce an engineered cardiac patch is an effective way to improve the myocardium infarction area function. Here, shape memory polymers of the polyurethane/polyaniline/silicon oxide (PU/PANI/SiO₂) electrospinning sub-micron fiber patch were precisely produced in the case of the hydrogen bonding effect and interaction between the carboxyl groups to provide compatibility, phase mixing/miscibility, and stability. The sub-micron fiber patch prepared by our group has some remarkable characteristics, such as sub-micron fibers, 3D porous structure, special thickness to simulate the extracellular matrix (ECM), elastic deformation, good properties in conducting weak electrical signals, stability to maintain the whole structure, and self-adhesion. This sub-micron fiber material has been proven to be effective, easy, and reliable. Through precise design of the material system, structure regulation, and performance optimization, the aim is to produce a sub-micron fiber cardiac patch to simulate the myocardium ECM and improve conductive signal transduction for potential MI therapy.

Design and Characterization of Sodium Alginate and Poly(vinyl) Alcohol Hydrogels for Enhanced Skin Delivery of Quercetin

Nature has led to the discovery of biopolymers with noteworthy pharmaceutical applications. Blended biopolymers have demonstrated promising characteristics when compared with their individual counterparts. Sodium alginate (SA) is a marine polymer that has demonstrated the ability to form hydrogels, an interesting property for the development of cutaneous formulations. Predicting the good performance of blended biopolymers, a novel series of hybrid hydrogels based on SA and poly(vinyl) alcohol (PVA) were prepared. Quercetin, a natural polyphenolic flavonoid commonly found in fruits and vegetables, is widely known for its strong anti-inflammatory and antioxidant activity, thus with potential applications against melanoma, dermatitis, psoriasis, and skin ageing. Here, hydrogels were produced at different ratios of SA and PVA. The surface morphology, structure, interaction of polymers, the capacity to absorb water and the entrapment efficiency of quercetin were evaluated for the blended hydrogels. Targeting the cutaneous application of the formulations, the rheological properties of all unloaded and quercetin-loaded hydrogels revealed pseudoplastic behavior, evidence of non-thixotropy, good resistance to deformation, and profile maintenance with temperatures ranging from 20 °C up to 40 °C. The incorporation of quercetin in the hydrogel retained its antioxidant activity, confirmed by radical scavenging assays (ABTS and DPPH). The permeability of quercetin through the skin showed different penetration/permeation profiles according to the hydrogel's blend. This behavior will allow the selection of SA-PVA at 2/1 ratio for a local and prolonged skin effect, making the use of these hydrogels a good solution to consider for the treatment of skin ageing and inflammation.

Recent advances in tissue engineering scaffolds based on polyurethane and modified polyurethane

Organ repair, regeneration, and transplantation are constantly in demand due to various acute, chronic, congenital, and infectious diseases. Apart from traditional remedies, tissue engineering (TE) is among the most effective methods for the repair of damaged tissues via merging the cells, growth factors, and scaffolds. With regards to TE scaffold fabrication technology, polyurethane (PU), a high-performance medical grade synthetic polymer and bioactive material has gained significant attention. PU possesses exclusive biocompatibility, biodegradability, and modifiable chemical, mechanical and thermal properties, owing to its unique structure-properties relationship. During the past few decades, PU TE scaffold bioactive properties have been incorporated or enhanced with biodegradable, electroactive, surface-functionalised, ayurvedic products, ceramics, glass, growth factors, metals, and natural polymers, resulting in the formation of modified polyurethanes (MPUs). This review focuses on the recent advances of PU/MPU scaffolds, especially on the biomedical applications in soft and hard tissue engineering and regenerative medicine. The scientific issues with regards to the PU/MPU scaffolds, such as biodegradation, electroactivity, surface functionalisation, and incorporation of active moieties are also highlighted along with some suggestions for future work.

Novel chitosan/guar gum/PVA hydrogel: Preparation, characterization and antimicrobial activity evaluation

A series of chitosan/poly(vinyl alcohol)/guar gum (CS/PVA/GG) blends were prepared. The synthesis was carried out using different combinations of CS and GG, while keeping PVA constant by casting solution method. The effect of formaldehyde as a crosslinking agent was also evaluated. The blends were characterized by scanning electron microscopy (SEM), Fourier Transform Infra-red (FTIR) and X-ray powder diffraction (XRD). Additionally, the swelling ratio along with antimicrobial activity was also studied. SEM exhibited the phenomenon that surface morphology was mostly affected by blend ratios and cross-linker. The XRD shows the crystalline structure of blends. The FTIR confirmed the strong intermolecular bonding between polymers. Swelling exhibits that cross-linking affects the hydrophilicity of blends and swelling was excellent for S4 blend. The prepared blends showed promising antimicrobial activity against P. multocida, S. aureus, E. coli, and B. subtilis bacterial agents. The data concludes that GG, CS and PVA ternary blends could possibly be used for the biomedical applications.

Antithrombogenic properties of Tulbaghia violacea–loaded polycaprolactone nanofibers

A broad range of polymers have been utilized for the development of blood-contacting implantable medical devices; however, their rate of failure has raised the need for developing more hemocompatible biomaterial surfaces. In this study, a novel scaffold based on polycaprolactone incorporated with 10% and 15% (w/w) Tulbaghia violacea plant extracts were fabricated using electrospinning technique. The fabricated scaffolds were then treated with T. violacea aqueous plant extracts (100 and 1000 µg/mL) to investigate their use as interfaces for blood-contacting implants. The 10% Tvio scaffold produced the lowest mean fibre diameter (193 ± 30 nm), whereas the 15% Tvio scaffold produces the highest mean fibre diameter (538 ± 236 nm) when compared with the control polycaprolactone (275 ± 61 nm) scaffold. The number of adhered platelets was directly linked to fibre diameter and concentration of plant extract in such a way that the lowest fibre diameter scaffold (10% Tvio) inhibited platelet adhesion, whereas more platelets adhered to the scaffold with the highest fibre diameter (15% Tvio scaffolds). There was also an increase in platelet adhesion as the concentration of T. violacea was increased from 100 to 1000 µg/mL for all designed scaffolds. The improved blood compatibility demonstrated by the 10% Tvio scaffold suggests that the plant possesses antithrombogenic properties, particularly at lower concentrations.