Immune response following transcatheter aortic valve procedure

Aortic valve stenosis is the most common type of heart valve disease in the United States and Europe and calcific aortic stenosis (AS) affects 2-7% of people aged 65 years and older. Aortic valve replacement (AVR) is the only effective treatment for individuals with this condition. Transcatheter Aortic Valve Replacement (TAVR) has been widely accepted as a minimally invasive therapeutic approach for addressing symptomatic AS in patients who are considered to have a high risk for traditional surgical intervention. TAVR procedure may have a paradoxical effect on the immune system and inflammatory status. A major portion of these immune responses is regulated by activating or inhibiting inflammatory monocytes and the complement system with subsequent changes in inflammatory cytokines. TAVR has the potential to induce various concurrent exposures, including disruption of the native valve, hemodynamic changes, antigenicity of the bioprosthesis, and vascular damage, which finally lead to the development of inflammation. On the other hand, it is important to acknowledge that TAVR may also have anti-inflammatory effects by helping in the resolution of stenosis.The inflammation and immune response following TAVR are complex processes that significantly impact procedural outcomes and patient well-being. Understanding the underlying mechanisms, identifying biomarkers of inflammation, and exploring therapeutic interventions to modulate these responses are crucial for optimizing TAVR outcomes. Further research is warranted to elucidate the precise immunological dynamics and develop tailored strategies to attenuate inflammation and enhance post-TAVR healing while minimizing complications.

Magnetic nanocomposite through coating mannose-functionalized metal-organic framework with biopolymeric pectin hydrogel beads: A potential targeted anticancer oral delivery system

This study designed magnetic nanocomposite hydrogel beads for a potential targeted anticancer oral delivery system. To end this, nanohybrids of Fe3O4/MIL-88(Fe) (FM) were synthesized through in-situ method by the treatment of terephthalic acid (TPA) and (Fe(NO3)3·9H2O) in the presence of Fe3O4 nanoparticles. They were then modified with mannose sugar as an anticancer receptor to achieve a targeted drug delivery system. After loading methotrexate (MTX), they were coated with pH-sensitive pectin hydrogel beads in the presence of a calcium chloride crosslinker for possible transferring the nanohybrids to the intestine through the acidic environment of the digestive system. The results of different analysis techniques showed that the materials were properly synthesized, coated, and loaded. The designed magnetic nanocomposite hydrogel beads showed pH-sensitive swelling and drug release rate, protecting MTX from the acidic environment of the stomach. MTT test revealed a good cytotoxicity toward colon cancer HT29 cell lines. Remarkably, the functionalization of MTX-loaded FM nanohybrids with mannose (MTX-MFM) enhanced their anticancer properties up to about 20 %. The results recommended that the prepared novel magnetic nanocomposite hydrogel beads have a good potential to be used as a targeted anticancer oral delivery system.

Recent advances in fluorescence nanoparticles "quantum dots" as gene delivery system: A review

Biomaterial scientists have recently focused their attention on evaluating various aspects of delivering genetic materials into cells to induce a cellular response. The process involves complexing negatively charged plasmids, followed by delivering the resulting package into cells, a process facilitated by lipids, peptides, viruses, synthetically modified cationic polymers, and specific inorganic nanomaterials. In the context of gene delivery for specific imaging in biological and biomedical applications, fluorescence nanocrystals or quantum dots (QDs) present promising candidates as engineered nanoparticles (NPs). This literature review study aims to investigate the potential of QDs as a novel tool for gene delivery to retinal cells. The proficiency of QDs in this context arises from their unique physicochemical characteristics, including optical electronic and catalytic properties, which render them viable options for biosensing imaging, drug delivery, and gene delivery applications. In the field of gene delivery to the retinal cells, factors such as photoluminescence, quantum yield, biocompatibility, size, and shape play crucial roles in the utilization of QDs. In this paper, we discuss the most appropriate credentials and briefly outline the findings, supported by relevant illustrative samples, to explore the delivery of genetic material utilizing QDs.

A review on the impacts of metal/metal nanoparticles on characteristics of hydrogels: Special focus on carbohydrate polymers

Hydrogels with very interesting properties such as high water content, porosity, swelling, and mimicking the structure of the extracellular matrix (ECM) are promising candidates for a variety of applications. Recently, great efforts are being made to improve the shape and functionality of three-dimensional (3D) hydrogels. One of the most promising approaches is the incorporation of metal or metal nanoparticles (NPs) into hydrogels made of natural and synthetic polymers such as proteins, carbohydrates (i.e. chitosan, carboxymethyl cellulose, hyaluronic acid, etc), and the development of dynamic functional hydrogels that have been extensively studied. This review article focuses on the incorporation of metals or metal NPs into hydrogels to enhance their functionality and properties. In the first part, various metal-based hydrogels including metal- coordinated hydrogels, metal-nanocomposite hydrogels, and their synthesis methods are discussed. Subsequently, various properties of metal-containing hydrogels such as mechanical, self-healing, bioadhesion, antibacterial activity, and conductivity are explained. Finally, stimuli-responsive metal-based hydrogels are discussed with a special focus on carbohydrate polymers. This review article presents a new perspective on the development of hydrogels for various biomedical applications.

Encapsulation of thymol and menthol loaded N/S co-doped carbon dots derived from a mixture of herbal extracts as theranostic agents with anticancer properties

This research was conducted by synthesizing carbon dots MNE-CDs (mixed natural extract-carbon dots) based on mixed natural extract (ginger, garlic, turmeric) through the hydrothermal routh. Menthol and thymol were loaded as multi-therapeutic drugs with the addition of the bio-enhancer loaded on MNE-CDs with the hydrothermal method during a separate stage. These nanostructures were successfully encapsulated in chitosan by the nanospray drying method to enhance sustainability and release control. This study answered three of these issues by fabricating novel carbon dots for anticancer potential, release behavior and bioimaging at the same time. Preparation carbon dots are characterized using UV-vis, PL, FE-SEM, DLS, EDX, and FT-IR analysis. A moderate and sustained release profile of encapsulated carbon dots was noticed in comparison to the free carbon dots over 48 h of study in both simulated physicological environment (pH 7.4) and tumor tissue (pH 5.2) conditions. It was found that the release of bioactive substances from encapsulated samples was significantly attenuated. The cell viability assay showed all the samples, including free and encapsulated carbon dots, offered acceptable cytotoxicity against MCF-7 breast cancer cells. Despite this, the toxicity of free carbon dots is more than the encapsulated samples, and also the enhancement in anticancer potential was not observed for carbon dots loaded with menthol and thymol. Upon the obtained results, the synthesized fluorescence N/S co-doped carbon dots hold great anticancer potential and biological fluorescent labeling.

Recent progress in tannic acid based approaches as a natural polyphenolic biomaterial for cancer therapy: A review

Significant advancements have been noticed in cancer therapy for decades. Despite this, there are still many critical challenges ahead, including multidrug resistance, drug instability, and side effects. To overcome obstacles of these problems, various types of materials in biomedical research have been explored. Chief among them, the applications of natural compounds have grown rapidly due to their superb biological activities. Natural compounds, especially polyphenolic compounds, play a positive and great role in cancer therapy. Tannic acid (TA), one of the most famous polyphenols, has attracted widespread attention in the field of cancer treatment with unique structural, physicochemical, pharmaceutical, anticancer, antiviral, antioxidant and other strong biological features. This review concentrated on the basic structure along with the important role of TA in tuning oncological signal pathways firstly, and then focused on the use of TA in chemotherapy and preparation of delivery systems including nanoparticles and hydrogels for cancer therapy. Besides, the application of TA/Fe3+ complex coating in photothermal therapy, chemodynamic therapy, combined therapy and theranostics is discussed.

Matricaria chamomilla essential oil-loaded hybrid electrospun nanofibers based on polycaprolactone/sulfonated chitosan/ZIF-8 nanoparticles for wound healing acceleration

Recently, developing antibacterial wound dressings based on biomaterials display good biocompatibility and the potential to accelerate wound healing. For this aim, we prepared eco-friendly and biodegradable nanofibers (NFs) based on N-(3-sulfopropyl)chitosan/ poly (ε-caprolactone) incorporated by zeolite imidazolate framework-8 nanoparticles (ZIF-8 NPs) and chamomile essential oil (MCEO) via the electrospinning technique for their efficacy as wound dressing scaffolds. Fabricated NFs were characterized and studied for their structural, morphological, mechanical, hydrophilic, and thermal stability properties. The results of scanning electron microscopy (SEM) revealed that adding the ZIF-8 NPs/ MCEO, very slightly influenced the average diameter of NFs (PCL/SPCS (90:10) with 90 ± 32 nm). The developed uniform MCEO-loaded ZIF-8/PCL/SPCS NFs displayed better cytocompatibility, proliferation, and physicochemical properties (e.g. thermal stability and mechanical properties) than neat NFs. The results of cytocompatibility, DAPI (4',6-diamidino-2-phenylindole) staining study, and SEM micrographs demonstrated that formulated NFs had promising adhesion and proliferation against normal human foreskin fibroblasts-2 (HFF-2 cell line). The prepared NFs revealed excellent antibacterial activity against both Staphylococcus aureus and Escherichia coli with inhibition of 32.3 mm and 31.2 mm, respectively. Accordingly, the newly developed antibacterial NFs hold great potential as effective biomaterials for use as an active platform in wound healing applications.

Thermoplastic starch/bentonite clay nanocomposite reinforced with vitamin B2: Physicochemical characteristics and release behavior

This study presents the development and characterization of a nanocomposite material, consisting of thermoplastic starch (TPS) reinforced with bentonite clay (BC) and encapsulated with vitamin B₂ (VB). The research is motivated by the potential of TPS as a renewable and biodegradable substitute for petroleum-based materials in the biopolymer industry. The effects of VB on the physicochemical properties of TPS/BC films, including mechanical and thermal properties, water uptake, and weight loss in water, were investigated. In addition, the surface morphology and chemical composition of the TPS samples were analyzed using high-resolution SEM microscopy and EDS, providing insight into the structure-property relationship of the nanocomposites. The results showed that the addition of VB significantly increased the tensile strength and Young's modulus of TPS/BC films, with the highest values observed for nanocomposites containing 5 php of VB and 3 php of BC. Furthermore, the release of VB was controlled by the BC content, with higher BC content leading to lower VB release. These findings demonstrate the potential of TPS/BC/VB nanocomposites as environmentally friendly materials with improved mechanical properties and controlled release of VB, which can have significant applications in the biopolymer industry.

Gentamicin-loaded chitosan/folic acid-based carbon quantum dots nanocomposite hydrogel films as potential antimicrobial wound dressing

BACKGROUND

To provide effective healing in the wound, various carbohydrate polymers are commonly utilized that are highly potent platforms as wound dressing films. In this work, novel antibacterial flexible polymeric hydrogel films were designed via crosslinking polymeric chitosan (CS) with folic acid-based carbon quantum dots (CQDs). To end this, folic acid as a bio-precursor is used to synthesize CQDs through the hydrothermal technique. The synthesized CQDs as a crosslinking agent was performed at different concentrations to construct nanocomposite hydrogel films via the casting technique. Also, gentamicin (GM), L-Arginine and glycerol were supplemented in the formulation of nanocomposite since their antibiotic, bioactivity and plasticizing ability, respectively.

RESULTS

The successful construction of films were verified with different methods (FT-IR, UV-Vis, PL, SEM, and AFM analyses). The GM release profile displayed a controlled release manner over 48 h with a low initial burst release in the simulated wound media (PBS, pH 7.4). Antibacterial and in vitro cytotoxicity results showed a significant activity toward different gram-positive and negative bacterial strains (about 2.5 ± 0.1 cm inhibition zones) and a desired cytocompatibility against Human skin fibroblast (HFF-1) cells (over 80% cell viability), respectively.

CONCLUSION

The obtained results recommend CQDs-crosslinked CS (CS/CQD) nanocomposite as a potent antimicrobial wound dressing.

Graphene-MoS2 polyfunctional hybrid hydrogels for the healing of transected Achilles tendon

Healing of injured tendon is a major clinical challenge in orthopaedic medicine, due to the poor regenerative potential of this tissue. Two-dimensional nanomaterials, as versatile scaffolds, have shown a great potential to support, trigger and accelerate the tendon regeneration. However, weak mechanical properties, poor functionality and low biocompatibility of these scaffolds as well as post-surgery infections are main drawbacks that limit their development in the higher clinical phases. In this work, a series of hydrogels consisting polyglycerol functionalized reduced graphene oxide (PG), polyglycerol-functionalized molybdenum disulfide (PMoS₂) and PG/PMoS₂ hybrid within the gelatin matrix are formulated in new scaffolds and their ability for the healing of injured Achilles tendon, due to their high mechanical properties, low toxicity, cell proliferation enhancement, and antibacterial activities is investigated. While scaffolds containing PG and PMoS₂ showed a moderate tendon regeneration and anti-inflammatory effect, respectively, their hybridization into PG/PMoS₂ demonstrated a synergistic healing efficiency. Along the same line, an accelerated return of tendon function with low peritendinous adhesion and low cross-sectional area in animal group treated with scaffold containing PG/PMoS₂ was observed. Taking advantage of the high biocompatibility, high strength, straightforward construction and fast tendon regeneration, PG/PMoS₂ can be used as a new scaffold for the future tissue engineering.

Electrospun nanofibers based on carboxymethyl cellulose/polyvinyl alcohol as a potential antimicrobial wound dressing

In this work, citric acid-based quantum dots (CA-QDs) as a novel and safe crosslinked agent was applied in different feeding ratios (5-15 wt%) to synthesize carboxymethyl cellulose/polyvinyl alcohol (CMC/PVA) nanofibers (NFs) for the first time. Colistin (CL) as an antibacterial agent was also loaded (2 w/w%) during the synthesizing process of CMC/PVA electrospun NFs to trigger antimicrobial properties. The morphological, hydrophilic, and mechanical properties of the prepared NFs were fully investigated with different techniques. The electrospun NFs with crosslinking ratios of 10 wt% CA-QDs revealed appropriate mechanical properties. According to cell culture data, the prepared NFs demonstrated good cytocompatibility against HFF-1 cells (over 80% cell viability). Remarkably, CL-loaded NFs showed desired antibacterial efficacy against S. aureus, E. coli, K. pneumoniae, and P. aeruginosa with 1.0-1.4, 1.3-1.4, 0.8-1.0, and 1.3-1.5 cm inhibition zones, respectively. These outcomes suggested that the fabricated NFs can be useful as wound healing scaffolds.

Sulfonated magnetic sugarcane bagasse as an efficient natural polymer-based catalyst for the synthesis of nitrogen-containing heterocyclic rings in water

A new species of catalysts that are prepared from biocompatible materials is demonstrated. Sulfonated magnetic sugarcane bagasse has been synthesized as a novel biodegradable and robust heterogeneous catalyst for organic transformations. The catalyst was characterized by different techniques. Next, the efficiency of this acid catalyst was examined with multi-component reactions for the synthesis of some biologically active scaffolds of heterocyclic organic compounds such 2,3-dihydroquinazolin-4(1H)-ones and pyrido[2,3-d]pyrimidin-4-one derivatives. A wide range of these heterocycles was synthesized with excellent yields in short reaction times under green conditions. In all cases, sulfonated magnetic sugarcane bagasse could be simply collected using an external magnet and reused for several runs without any significant loss of catalytic activity.

Antisense agents against antibiotic-resistant bacteria

Abstract:

The dramatically increasing levels of antibiotic resistance are being seen worldwide, and is a significant threat to public health. Antibiotic and drug resistance is seen in various bacterial species. Antibiotic resistance is associated with increased morbidity and mortality and increased treatment costs. Antisense-relevant technologies include the utilization of oligonucleotide molecules to interfere with gene expression, as a new technique for the treatment of antibiotic-resistant bacteria has been proposed antisense agents or nucleic acids analogs with antibacterial properties, which are commonly very short and their size almost 10-20 bases and can be hinted to peptide nucleic acids (PNAs), phosphorodiamidate morpholino oligomers (PPMOs) and locked nucleic acids (LNAs). This review highlights that PNAs, PPMOs, and LNAs target the genes that cause destroy the gene and inhibit the growth of bacteria. These results open a new perspective for therapeutic intervention. In future studies, it is necessary to examine different aspects of antisense agents, for example, safety, toxicity, and pharmacokinetic properties of antisense agents to be employed in clinical treatment.

Ultrasound-assisted synthesis of MIL-88(Fe) coordinated to carboxymethyl cellulose fibers: A safe carrier for highly sustained release of tetracycline

For stopping long-time harmful bacterial infection, designing a drug carrier with a highly prolonged release profile is a promising approach that is of interest to different biomedical areas. The subject of this work is to synthesis a novel carrier system through coordination of MIL-88(Fe) to carboxymethyl cellulose (CMC) for enhancing interaction between drug and carrier. We established an ultrasound-assisted synthetic method for in situ synthesis of MIL-88(Fe) in the presence of CMC resulting in CMC/MIL-88(Fe) composite. The CMC/MIL-88(Fe) was loaded with a high amount of Tetracycline (TC) by immersion of carrier to the TC aqueous solution. The release profile in the simulated physiological conditions, pH 7.4, revealed a low initial burst release followed by a sustained and prolonged release over 384 h. The in vitro cytotoxicity of CMC/MIL-88(Fe) against Human skin fibroblast (HFF-1) cells was calculated by MTT assay and showed a good cytocompatibility. The antibacterial activity was found for TC-loaded CMC/MIL-88(Fe) toward both E. coli and S. aureus with MIC 64 mg·ml^-1.

Fabrication and characterization of a titanium dioxide (TiO2) nanoparticles reinforced bio-nanocomposite containing Miswak (Salvadora persica L.) extract - the antimicrobial, thermo-physical and barrier properties

Objective: The microbial, physico-chemical and optical corruptions threaten a variety of foods and drugs and consequently the human biological safety and its accessible resources. The humanbeing's tendency towards bio-based materials and natural plant-extracts led to an increase in the usage of antimicrobial biocomposites based on medicinal herbs. Miswak (Salvadora persica L.) extract (SPE) has been proved effective for its antimicrobial and other biological activities. Therefore, in this study, titanium dioxide (TiO₂) nanoparticles (TONP) and SPE were applied to fabricate antimicrobial carboxymethyl cellulose (Na-CMC) based bio-nanocomposites which would simultaneously promote some thermo-physical and barrier properties. Methods: CMC-neat film (C1), CMC/TONP-2% (C2) and CMC/TONP-2% with 150, 300 and 450 mg/mL SPE (SPE150, SPE30 and SPE450, respectively) were fabricated. The physical and mechanical properties; elemental mapping analysis (MAP), X-ray diffraction (XRD), scanning electron microscopy (SEM), thermal gravimetric analysis (TGA-DTG); fourier transform infrared (FTIR), energy-dispersive X-ray (EDX) and UV-vis spectroscopies were done to further validate the results. Results: Addition of TONP (2%) improved the blocking of UV light at 280 nm while SPE-containing nanocomposites completely blocked it. FTIR, XRD and SEM confirmed the formation of homogeneous films and high miscibility of applied materials. TONP led to an increase in Young's modulus (YM) and stress at break (SB) while SPE decreased them and enhanced the elongation to break (EB) (flexibility) of the active nanocomposites. Compared to CMC-film, the thermo-gravimetric analysis (TGA-DTG) showed a higher thermal stability for CMC/TONP and CMC/TONP/SPE nanocomposites. The EDX spectroscopy and elemental mapping analysis (MAP) proved the existence and well-distributedness of Na, K, Cl, S, Ti, F and N elements in SPE-activated nanocomposites. The pure SPE and SPE-activated nanocomposites showed a favorable antimicrobial activity against both gram-positive (Staphylococcus aureus) and negative (Escherichia coli) bacteria. Conclusion: The CMC-TiO₂-SPE nanocomposites were homogeneously produced. Combination of TiO₂ nanoparticles and dose-dependent SPE led to an improvement of thermal stability, and high potential in antimicrobial and UV-barrier properties. These results can generally highlight the role of the fabricated antimicrobial bio-nanocomposites as a based for different applications especially in food/drug packaging or coating.