Polycaprolactone/Chitosan Composite Nanofiber Membrane as a Preferred Scaffold for the Culture of Mesothelial Cells and the Repair of Damaged Mesothelium

Electrospun polycaprolactone-chitosan nanofibers on a zinc mesh as biodegradable guided bone-regeneration membranes with enhanced mechanical, antibacterial, and osteogenic properties for alveolar bone-repair applications

Guided bone-regeneration membrane (GBRM) is commonly used in bone-repair surgery because it blocks fibroblast proliferation and provides spatial support in bone-defect spaces. However, the need for removal surgery and the lack of antibacterial properties of conventional GBRM limit its therapeutic applicability for alveolar bone defects. Here we developed a GBRM for alveolar bone-repair and -regeneration applications through double-sided electrospinning of polycaprolactone and chitosan layers on a Zn mesh surface (denoted DSZM). The DSZM showed a UTS of ∼25.6 MPa, elongation of ∼16.1%, strength-elongation product of ∼0.413 GPa%, and ultrahigh spatial maintenance ability, and the UTS was over 6 times higher than that of commercial Bio-Gide membrane. The DSZM exhibited a corrosion rate of ∼17 µm/y and a Zn ion concentration of ∼0.23 µg/ml after 1 month of immersion in Hanks' solution. The DSZM showed direct and indirect cytocompatibility with exceptional osteogenic differentiation and calcium deposition toward MC3T3-E1 cells. Further, the DSZM showed strongly sustained antibacterial activity against S. aureus and osteogenesis in a rat critical-sized maxillary defect model. Overall, the DSZM fits the requirements for alveolar bone-repair and -regeneration applications as a biodegradable GBRM material due to its spatial support, suitable degradability, cytocompatibility, and antibacterial and osteogenic capabilities. STATEMENT OF SIGNIFICANCE: This work reports the mechanical properties, antibacterial ability and osteogenic properties of electrospun PCL-CS nanofiber on Zn mesh as biodegradable guided bone-regeneration membrane for alveolar bone-repair applications. Our findings demonstrate that the DSZM prepared by double-sided electrospinning of PCL-CS layers on Zn mesh showed a UTS of ∼25.6 MPa, elongation of ∼16.1%, strength-elongation product of ∼0.413 GPa%, and ultrahigh spatial maintenance ability, and the UTS was over 6 times greater than that of commercial Bio-Gide® membrane. The DSZM showed direct and indirect cytocompatibility with exceptional osteogenic differentiation and calcium deposition toward MC3T3-E1 cells. Further, the DSZM showed strongly sustained antibacterial activity against S. aureus and osteogenesis in a rat critical-sized maxillary defect model.

Composite Polycaprolactone/Gelatin Nanofiber Membrane Scaffolds for Mesothelial Cell Culture and Delivery in Mesothelium Repair

To repair damaged mesothelium tissue, which lines internal organs and cavities, a tissue engineering approach with mesothelial cells seeded to a functional nanostructured scaffold is a promising approach. Therefore, this study explored the uses of electrospun nanofiber membrane scaffolds (NMSs) as scaffolds for mesothelial cell culture and transplantation. We fabricated a composite NMS through electrospinning by blending polycaprolactone (PCL) with gelatin. The addition of gelatin enhanced the membrane's hydrophilicity while maintaining its mechanical strength and promoted cell attachment. The in vitro study demonstrated enhanced adhesion of mesothelial cells to the scaffold with improved morphology and increased phenotypic expression of key marker proteins calretinin and E-cadherin in PCL/gelatin compared to pure PCL NMSs. In vivo studies in rats revealed that only cell-seeded PCL/gelatin NMS constructs fostered mesothelial healing. Implantation of these constructs leads to the regeneration of new mesothelium tissue. The neo-mesothelium is similar to native mesothelium from hematoxylin and eosin (H&E) and immunohistochemical staining. Taken together, the PCL/gelatin NMSs can be a promising scaffold for mesothelial cell attachment, proliferation, and differentiation, and the cell/scaffold construct can be used in therapeutic applications to reconstruct a mesothelium layer.

Preparation of amphiphilic polyquaternium nanofiber films with antibacterial activity via environmentally friendly microfluidic-blow-spinning for green food packaging applications

Green food packaging plays an important role in environmental protection and sustainable development. Therefore, it is advisable to employ low-energy consumption manufacturing techniques, select environmentally friendly materials, and focus on cost-effectiveness with high production yields during the production process. In this study, an amphiphilic polyquaternium called PBzCl was proposed and synthesized by free radical polymerization of cost-efficient quaternary ammonium salts and methacrylate monomers. Then, biodegradable PCL and PVP were used to rapidly prepare the PBzCl@PCL/PVP nanofiber films via environmentally friendly microfluidic-blow-spinning (MBS). The best antibacterial effect was observed at a PBzCl loading concentration of 13.5%, and the PBzCl@PCL/PVP nanofiber films had 91% and 100% antibacterial rates against Escherichia coli and Staphylococcus aureus, respectively. Besides, the loading of PBzCl improved the water stability of the PCL/PVP nanofiber films, and the films also showed excellent biocompatibility. Overall, PBzCl@PCL/PVP nanofibre films have promising food packaging potential.

Development and characterization of Polycaprolactone/chitosan-based scaffolds for tissue engineering of various organs: A review

Research in creating 3D structures mirroring the extracellular matrix (ECM) with accurate environmental cues holds paramount significance in biological applications.Biomaterials that replicate ECM properties-mechanical, physicochemical, and biological-emerge as pivotal tools in mimicking ECM behavior.Incorporating synthetic and natural biomaterials is widely used to produce scaffolds suitable for the intended organs.Polycaprolactone (PCL), a synthetic biomaterial, boasts commendable mechanical properties, albeit with relatively modest biological attributes due to its hydrophobic nature.Chitosan (CTS) exhibits strong biological traits but lacks mechanical resilience for complex tissue regeneration.Notably, both PCL and CTS have demonstrated their application in tissue engineering for diverse types of tissues.Their combination across varying PCL:CTS ratios has increased the likelihood of fabricating scaffolds to address defects in sturdy and pliable tissues.This comprehensive analysis aspires to accentuate their distinct attributes within tissue engineering across different organs.The central focus resides in the role of PCL:CTS-based scaffolds, elucidating their contribution to the evolution of advanced functional 3D frameworks tailored for tissue engineering across diverse organs.Moreover, this discourse delves into the considerations pertinent to each organ.

Advanced postoperative tissue antiadhesive membranes enabled with electrospun nanofibers

Tissue adhesion is one of the most common postoperative complications, which is frequently accompanied by inflammation, pain, and even dyskinesia, significantly reducing the quality of life of patients. Thus, to prevent the formation of tissue adhesions, various strategies have been explored. Among these methods, placing anti-adhesion membranes over the injured site to separate the wound from surrounding tissues is a simple and prominently favored method. Recently, electrospun nanofibers have been the most frequently investigated antiadhesive membranes due to their tunable porous structure and high porosities. They not only can act as an essential barrier and functional carrier system but also allow for high permeability and nutrient transport, showing great potential for preventing tissue adhesion. Herein, we provide a short review of the most recent applications of electrospun nanofibrous antiadhesive membranes in tendons, the abdominal cavity, dural sac, pericardium, and meninges. Firstly, each section highlights the most representative examples and they are sorted based on the latest progress of related research. Moreover, the design principles, preparation strategies, overall performances, and existing problems are highlighted and evaluated. Finally, the current challenges and several future ways to develop electrospun nanofibrous antiadhesive membranes are proposed. The systematic discussion and proposed directions can shed light on ideas and guide the reasonable design of electrospun nanofibrous membranes, contributing to the development of exceptional tissue anti-adhesive materials in the foreseeable future.

Nanofibers of chitosan-polycaprolactone blends as active support for photocatalytic nanoparticles: Outstanding role of chitosan in the degradation of an organic dye in water

Hybrid nanofibers of a chitosan-polycaprolactone blend containing titanium dioxide nanoparticles TiO2NPs, were prepared through electrospinning to study their adsorption and photocatalytic degradation capabilities of the model organic water pollutants, rhodamine B, RhB. To obtain uniform and bead-free nanofibers, an optimization of the electrospinning parameters was performed. The optimization was carried out by systematically adjusting the solution conditions (solvent, concentration, and polymer ratio) and instrumental parameters (voltage, needle tip-collector distance, and flow). The obtained materials were characterized by FT-IR, TGA, DSC, SEM, TEM, mechanical tensile test, and water contact angle. The photoactivity was investigated using a batch-type system by following UV-Vis absorbance and fluorescence of RhB. TiO2NPs were incorporated ex-situ into the polymer matrix, contributing to good mechanical properties and higher hydrophilicity of the material. The results showed that the presence of chitosan in the nanofibers significantly increased the adsorption of RhB and its photocatalytic degradation by TiO2NPs (5, 55 and 80 % of RhB degradation with NFs of PCL, TiO2/PCL and TiO2/CS-PCL, after 30 h of light irradiation, respectively), evidencing a synergistic effect between them. The results are attributed to an attraction of RhB by chitosan to the vicinity of TiO2NPs, favouring initial adsorption and degradation, phenomenon known as "bait-and-hook-and-destruct" effect.

Bioactive Nanostructured Scaffold-Based Approach for Tendon and Ligament Tissue Engineering

An effective therapeutic strategy to treat tendon or ligament injury continues to be a clinical challenge due to the limited natural healing capacity of these tissues. Furthermore, the repaired tendons or ligaments usually possess inferior mechanical properties and impaired functions. Tissue engineering can restore the physiological functions of tissues using biomaterials, cells, and suitable biochemical signals. It has produced encouraging clinical outcomes, forming tendon or ligament-like tissues with similar compositional, structural, and functional attributes to the native tissues. This paper starts by reviewing tendon/ligament structure and healing mechanisms, followed by describing the bioactive nanostructured scaffolds used in tendon and ligament tissue engineering, with emphasis on electrospun fibrous scaffolds. The natural and synthetic polymers for scaffold preparation, as well as the biological and physical cues offered by incorporating growth factors in the scaffolds or by dynamic cyclic stretching of the scaffolds, are also covered. It is expected to present a comprehensive clinical, biological, and biomaterial insight into advanced tissue engineering-based therapeutics for tendon and ligament repair.

Improving Solubility and Permeability of Hesperidin through Electrospun Orange-Peel-Extract-Loaded Nanofibers

Orange peel, which is a rich source of polyphenolic compounds, including hesperidin, is produced as waste in production. Therefore, optimization of the extraction of hesperidin was performed to obtain its highest content. The influence of process parameters such as the kind of extraction mixture, its temperature and the number of repetitions of the cycles on hesperidin content, the total content of phenolic compounds and antioxidant (DPPH scavenging assay) as well as anti-inflammation activities (inhibition of hyaluronidase activity) was checked. Methanol and temperature were key parameters determining the efficiency of extraction in terms of the possibility of extracting compounds with the highest biological activity. The optimal parameters of the orange peel extraction process were 70% of methanol in the extraction mixture, a temperature of 70 °C and 4 cycles per 20 min. The second part of the work focuses on developing electrospinning technology to synthesize nanofibers of polyvinylpyrrolidone (PVP) and hydroxypropyl-β-cyclodextrin (HPβCD) loaded with hesperidin-rich orange peel extract. This is a response to the circumvention of restrictions in the use of hesperidin due to its poor bioavailability resulting from low solubility and permeability. Dissolution studies showed improved hesperidin solubility (over eight-fold), while the PAMPA-GIT assay confirmed significantly better transmucosal penetration (over nine-fold). A DPPH scavenging assay of antioxidant activity as well as inhibition of hyaluronidase to express anti-inflammation activity was established for hesperidin in prepared electrospun nanofibers, especially those based on HPβCD and PVP. Thus, hesperidin-rich orange peel nanofibers may have potential buccal applications to induce improved systemic effects with pro-health biological activity.

Ovarian hormones influence immune response to liver ischemia-reperfusion

Liver injury occurs after ischemia and reperfusion (IR), as seen in transplant settings. Sex hormones have been implicated in many pathophysiological mechanisms in females and this could lead to liver protection under inflammatory reperfusion conditions where an excessive immune response occurs. Despite such assumptions, this fact needs to be further investigated. To address this, female and male C57BL/6J mice (8-12 weeks old) were studied. Bilateral ovariectomy (OVX) was performed in females to decrease estradiol levels. IR was performed, and after two weeks, all animals underwent a sham control operation or IR with euthanasia at the following time points after reperfusion: 6, 12, 24, and 48 h. IR triggered an inflammatory process in the liver with recruitment of neutrophils into the parenchyma of male mice. The female sham mice were protected against liver IR presenting no alteration of aminotransferase (ALT) levels compared to males. OVX caused loss of protection, increasing hepatic injury as represented by increased ALT levels and myeloperoxidase (MPO) activity. Female sham mice showed increased Akt phosphorylation and activation, while males showed reduced Akt activation. Estradiol pretreatment recovered ALT levels after IR injury, which was associated with decreased liver injury.

Current Research Trends in the Application of In Vitro Three-Dimensional Models of Liver Cells

The liver produces and stores various nutrients that are necessary for the body and serves as a chemical plant, metabolizing carbohydrates, fats, hormones, vitamins, and minerals. It is also a vital organ for detoxifying drugs and exogenous harmful substances. Culturing liver cells in vitro under three-dimensional (3D) conditions is considered a primary mechanism for liver tissue engineering. The 3D cell culture system is designed to allow cells to interact in an artificially created environment and has the advantage of mimicking the physiological characteristics of cells in vivo. This system facilitates contact between the cells and the extracellular matrix. Several technically different approaches have been proposed, including bioreactors, chips, and plate-based systems in fluid or static media composed of chemically diverse materials. Compared to conventional two-dimensional monolayer culture in vitro models, the ability to predict the function of the tissues, including the drug metabolism and chemical toxicity, has been enhanced by developing three-dimensional liver culture models. This review discussed the methodology of 3D cell cultures and summarized the advantages of an in vitro liver platform using 3D culture technology.

Electrospun Polycaprolactone/ZnO Nanocomposite Membranes with High Antipathogen Activity

The spread of bacterial, fungal, and viral diseases by airborne aerosol flows poses a serious threat to human health, so the development of highly effective antibacterial, antifungal and antiviral filters to protect the respiratory system is in great demand. In this study, we developed ZnO-modified polycaprolactone nanofibers (PCL-ZnO) by treating the nanofiber surface with plasma in a gaseous mixture of Ar/CO₂/C₂H₄ followed by the deposition of ZnO nanoparticles (NPs). The structure and chemical composition of the composite fibers were characterized by SEM, TEM, EDX, FTIR, and XPS methods. We demonstrated high material stability. The mats were tested against Gram-positive and Gram-negative pathogenic bacteria and pathogenic fungi and demonstrated high antibacterial and antifungal activity.