Regenerative medicine is a field that aims to influence and improvise the processes of tissue repair and restoration and to assist the body to heal and recover. In the field of hard tissue regeneration, bio-inert materials are being predominantly used, and there is a necessity to use bioactive materials that can help in better tissue–implant interactions and facilitate the healing and regeneration process. One such bioactive material that is being focused upon and studied extensively in the past few decades is bioactive glass (BG). The original bioactive glass (45S5) is composed of silicon dioxide, sodium dioxide, calcium oxide, and phosphorus pentoxide and is mainly referred to by its commercial name Bioglass. BG is mainly used for bone tissue regeneration due to its osteoconductivity and osteostimulation properties. The bioactivity of BG, however, is highly dependent on the compositional ratio of certain glass-forming system content. The manipulation of content ratio and the element compositional flexibility of BG-forming network developed other types of bioactive glasses with controllable chemical durability and chemical affinity with bone and bioactivity. This review article mainly discusses the basic information about silica-based bioactive glasses, including their composition, processing, and properties, as well as their medical applications such as in bone regeneration, as bone grafts, and as dental implant coatings.

Nanotechnology refers to nanomaterials of different dimensions, ranging in size from 1 to 100 nm. Shape and size, as well as properties of nanomaterials, depend on the materials based on their production. Nanomaterials are classified according to the type of substrate into carbon-based nanomaterials, metal-based nanomaterials, ceramic nanomaterials, lipid-based nanomaterials, semiconductor nanomaterials, and polymer nanomaterials. There are many physical methods that are widely used to produce nanomaterials, among these methods are inert gas condensation (IGC), physical evaporation, electric arc discharge, sputtering, and laser methods. Many characterization analysis techniques of nanomaterials, including ultraviolet–visible (UV–V) spectroscopy, XRD (X-ray diffraction), BET (Brunauere emmette teller), FESEM (Field emission scanning electron microscopy), FTIRS (Fourier transform infrared spectroscopy), TEM (Transmission electron microscopy) and Zeta size analysis. The unique properties that distinguish nanomaterials, allows them to penetrate many applications that directly serve the world. Nanomaterials have been utilized in various applications in the environment, agriculture, food industries, medical industries, chemical processing, and military industries.

Microbial fuel cells (MFCs) are an environmentally friendly technology and a source of renewable energy. It is used to generate electrical energy from organic waste using bacteria, which is an effective technology in wastewater treatment. The anode and the cathode electrodes and proton exchange membranes (PEM) are important components affecting the performance and operation of MFC. Conventional materials used in the manufacture of electrodes and membranes are insufficient to improve the efficiency of MFC. The use of nanomaterials in the manufacture of the anode had a prominent effect in improving the performance in terms of increasing the surface area, increasing the transfer of electrons from the anode to the cathode, biocompatibility, and biofilm formation and improving the oxidation reactions of organic waste using bacteria. The use of nanomaterials in the manufacture of the cathode also showed the improvement of cathode reactions or oxygen reduction reactions (ORR). The PEM has a prominent role in separating the anode and the cathode in the MFC, transferring protons from the anode chamber to the cathode chamber while preventing the transfer of oxygen. Nanomaterials have been used in the manufacture of membrane components, which led to improving the chemical and physical properties of the membranes and increasing the transfer rates of protons, thus improving the performance and efficiency of MFC in generating electrical energy and improving wastewater treatment.

In this work, we attempt to find an anisotropic solution for a compact star generated by gravitational decoupling in f(Q)-gravity theory having a null complexity factor. To do this, we initially derive the complexity factor condition in f(Q) gravity theory using the definition given by Herrera (Phys Rev D 97:044010, 2018) and then derived a bridge equation between gravitational potentials by assuming complexity factor to be zero (Contreras and Stuchlik in Eur Phys J C 82:706, 2022). Next, we obtain two systems of equations using the complete geometric deformation (CGD) approach. The first system of equations is assumed to be an isotropic system in f(Q)-gravity whose isotropic condition is similar to GR while the second system is dependent on deformation functions. The solution of the first system is obtained by Buchdahl’s spacetime geometry while the governing equations for the second system are solved through the mimic constraint approach along with vanishing complexity condition. The novelty of our work is to generalize the perfect fluid solution into an anisotropic domain in f(Q)-gravity theory with zero complexity for the first time. We present the solution’s analysis to test its physical viability. We exhibit that the existence of pressure anisotropy due to gravitational within the self-gravitating bounded object plays a vital role to stabilize the f(Q) gravity system. In addition, we show that the constant involved in the solution controls the direction of energy flow between the perfect fluid and generic fluid matter distributions.

In this paper, we present an anisotropic solution for static and spherically symmetric self-gravitating systems by demanding the vanishing of the complexity factor (Herrera in Phys Rev D 97:044010, 2018) along with the isotropization technique through the gravitational decoupling (GD) approach (Ovalle in Phys Rev D 95:104019, 2017) in $$f(\mathscr {T})$$f ( T ) -gravity theory. We begin by implementing gravitational decoupling via MGD scheme as the generating mechanism to obtain anisotropic solutions describing physically realizable static, spherical self-gravitating systems. We adopt the Krori–Barua ansatz and present two new classes of stellar solutions: the minimally deformed anisotropic solution with a vanishing complexity factor and the isotropic solution via gravitational decoupling. We demonstrate that both classes of solutions obey conditions of regularity, causality and stability. An interesting feature is the switch in trends of some of the thermodynamical quantities such as effective density, radial and transverse stresses at some finite radius, $$r=r_*$$r = r ∗ , depending on different values of the decoupling constant $$\beta $$β . We show that gravitational decoupling via the vanishing complexity factor enhances the stability of the stellar fluid surrounding the core’s central areas. By analyzing the effect of the decoupling constant $$\beta $$β on the $$M-Y_{TF}$$M - Y TF plots, (where $$Y_{TF}$$Y TF denotes the complexity factor) derived from both solutions, we find that a small contribution from the complexity factor leads to the prediction of lower maximum mass of a self-gravitating compact star via gravitational decoupling in $$f(\mathscr {T})$$f ( T ) -gravity compared to their pure $$f(\mathscr {T})$$f ( T ) -gravity counterparts. Furthermore, we have also determined the impact of decoupling constant $$\beta $$β and surface density on predicted radii via $$M{-}R$$M - R for some known compact objects.