Development of New Collagen/Clay Composite Biomaterials

The fabrication of collagen-based biomaterials for skin regeneration offers various challenges for tissue engineers. The purpose of this study was to obtain a novel series of composite biomaterials based on collagen and several types of clays. In order to investigate the influence of clay type on drug release behavior, the obtained collagen-based composite materials were further loaded with gentamicin. Physiochemical and biological analyses were performed to analyze the obtained nanocomposite materials after nanoclay embedding. Infrared spectra confirmed the inclusion of clay in the collagen polymeric matrix without any denaturation of triple helical conformation. All the composite samples revealed a slight change in the 2-theta values pointing toward a homogenous distribution of clay layers inside the collagen matrix with the obtaining of mainly intercalated collagen-clay structures, according X-ray diffraction analyses. The porosity of collagen/clay composite biomaterials varied depending on clay nanoparticles sort. Thermo-mechanical analyses indicated enhanced thermal and mechanical features for collagen composites as compared with neat type II collagen matrix. Biodegradation findings were supported by swelling studies, which indicated a more crosslinked structure due additional H bonding brought on by nanoclays. The biology tests demonstrated the influence of clay type on cellular viability but also on the antimicrobial behavior of composite scaffolds. All nanocomposite samples presented a delayed gentamicin release when compared with the collagen-gentamicin sample. The obtained results highlighted the importance of clay type selection as this affects the performances of the collagen-based composites as promising biomaterials for future applications in the biomedical field.

Therapeutic Applications of Halloysite

In recent years, nanomaterials have attracted significant research interest for applications in biomedicine. Many kinds of engineered nanomaterials, such as lipid nanoparticles, polymeric nanoparticles, porous nanomaterials, silica, and clay nanoparticles, have been investigated for use in drug delivery systems, regenerative medicine, and scaffolds for tissue engineering. Some of the most attractive nanoparticles for biomedical applications are nanoclays. According to their mineralogical composition, approximately 30 different nanoclays exist, and the more commonly used clays are bentonite, halloysite, kaolinite, laponite, and montmorillonite. For millennia, clay minerals have been extensively investigated for use in antidiarrhea solutions, anti-inflammatory agents, blood purification, reducing infections, and healing of stomach ulcers. This widespread use is due to their high porosity, surface properties, large surface area, excellent biocompatibility, the potential for sustained drug release, thermal and chemical stability. We begin this review by discussing the major nanoclay types and their application in biomedicine, focusing on current research areas for halloysite in biomedicine. Finally, recent trends and future directions in HNT research for biomedical application are explored.

Time fractional model of electro-osmotic Brinkman-type nanofluid with heat generation and chemical reaction effects: application in cleansing of contaminated water

Drilling fluids execute a dominant role in the extraction of oil and gas from the land and rocks. To enhance the efficiency of drilling fluid, clay nanoparticulate has been utilized. The inclusion of clay nanomaterial to drilling fluids significantly elevate their viscosity and thermal conductivity. Therefore, the present investigation is focused on the analysis of time-fractional free convective electro-osmotic flow of Brinkman-type drilling nanofluid with clay nanoparticles. The heat generation and chemical reaction characteristics and influence of the transverse magnetic field have also been taken into an account. The local mathematical model is formulated in terms of coupled PDEs along with appropriate physical conditions. The dimensional governing equations have been non-dimensionalized by using relative similarity variables to encounter the units and reduce the variables. Further, the non-dimensional local model has been artificially converted to a generalized model by utilizing the definition of time-fractional Caputo–Fabrizio derivative with the exponential kernel. The graphical results are analyzed via computational software Mathematica, to study the flow behavior against inserted parameters. From graphical analysis it has been observed qualitatively that the velocity field has been raised against the greater magnitude of electro-osmosis parameter $$Es$$ Es . Numerical table for Nusselt number is calculated from the obtained exact solutions. From the analysis 11.83% elevation in the rate of energy transition of drilling nanofluid has been reported in response of clay nanoparticles.

Maghnite: an innovative inorganic reinforcement utilized in the synthesis of polyamide 12 nanocomposites with optimized thermal and mechanical properties

This study will contribute to the identification and understanding of the reinforcement mechanisms of thermoplastic matrices by nanofillers. This aspect is addressed through the investigation of the thermal and mechanical properties of nanocomposites consisting of a polyamide 12 (PA12) matrix crammed with organically modified clay nanoparticles. An efficient approach to the synthesis of polyamide 12 (PA12) nanocomposites was investigated; Maghnite may be a processed Algerian mineral clay which will act both as a catalyst and as an inorganic reinforcement. Two sorts of organic substances were used, labeled CTA-Mag (1CEC) and CTA-Mag (2CEC), modified by cetyltrimethylammonium (CTA) ions. However, PA12/CTA-Mag nanocomposites are characterized by various physico-chemical techniques, XRD, FTIR, TGA, scanning and transmission electron microscopy (SEM and TEM). Measurements of tensile modulus, yield strength, lastingness, elongation at break and toughness were done to assess the behavior of the mechanical properties. Furthermore, we have analyzed the consequences of the mass fraction of the fillers on the structural, thermal and mechanical properties of those nanocomposites. Specific attention has been paid to the study of relationships between the macroscopic properties and therefore the structure of nanocomposites. Thermomechanical tests showed a big improvement within the properties of the nanocomposites compared to neat PA12.

Effect of Nanoparticles Surface Bonding and Aspect Ratio on Mechanical Properties of Highly Cross-Linked Epoxy Nanocomposites: Mesoscopic Simulations

The paper aims to study the mechanical properties of epoxy resin filled with clay nanoparticles (NPs), depending on their shapes and content on the surface of a modifying agent capable of forming covalent bonds with a polymer. The cylindrical clay nanoparticles with equal volume and different aspects ratios (disks, barrel, and stick) are addressed. The NPs’ bonding ratio with the polymer (RGC) is determined by the fraction of reactive groups and conversion time and varies from RGC = 0 (non-bonded nanoparticles) to RGC = 0.65 (more than half of the surface groups are linked with the polymer matrix). The performed simulations show the so-called load-bearing chains (LBCs) of chemically cross-linked monomers and modified nanoparticles to determine the mechanical properties of the simulated composites. The introduction of nanoparticles leads to the breaking of such chains, and the chemical cross-linking of NPs with the polymer matrix restores the LBCs and strengthens the composite. At small values of RGC, the largest value of the elastic modulus is found for systems filled with nanoparticles having the smallest surface area, and at high values of RGC, on the contrary, the systems containing disk-shaped particles with the largest surface area have a larger elastic modulus than the others. All calculations are performed within the framework of a mesoscopic model based on accurate mapping of the atomistic structures of the polymer matrix and nanoparticles into coarse-grained representations, which, if necessary, allow reverse data mapping and quantitative assessment of the state of the filled epoxy resin. On the other hand, the obtained data can be used to design the functional materials with specified mechanical properties based on other practically significant polymer matrices and nanofillers.