Direct ink writing (DIW) additive manufacturing is a versatile 3D printing technique for a broad range of materials. DIW can print a variety of materials provided that the ink is well-engineered with appropriate rheological properties. DIW could be an ideal technique in tissue engineering to repair and regenerate deformed or missing organs or tissues, for example, bone and tooth fracture that is a common problem that needs surgeon attention. A critical criterion in tissue engineering is that inserts must be compatible with their surrounding environment. Chemically produced calcium-rich materials are dominant in this application, especially for bone-related applications. These materials may be toxic leading to a rejection by the body that may need secondary surgery to repair. On the other hand, there is an abundance of biowaste building blocks that can be used for grafting with little adverse effect on the body. In this work, we report a bioderived ink made entirely of calcium derived from waste animal bones using a benign process. Calcium nanoparticles are extracted from the bones and the ink prepared by mixing with different biocompatible binders. The ink is used to print scaffolds with controlled porosity that allows better growth of cells. DIW printed parts show better mechanical properties and biocompatibility that are important for the grafting application. Degradation tests and a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay study were done to examine the biocompatibility of the extracted materials. In addition, discrete element modeling and computational fluid dynamics numerical methods are used in Rocky and Ansys software programs. This work shows that biowaste materials if well-engineered can be a never-ending source of raw materials for advanced application in orthopedic grafting.

In the present study, a dinuclear bis­(μ-acetate) dicopper­(II) complex [Cu2L2(μ1.1-CH3COO–)2] has been synthesized from a tridentate NNO Schiff Base ligand L (L = 2,4-dibromo-6-((3-(methylamino)­propylimino)­methyl)­phenol) and characterized by elemental, ultraviolet–visible (UV–vis), Fourier transform infrared (FTIR), 1H NMR, and electrospray ionization-mass spectrometry (ESI-MS) spectroscopic studies. The single-crystal X-ray structure, different noncovalent interactions, Hirshfeld surface analysis, and density functional theory (DFT) studies of the dinuclear complex were determined by crystallographic computational studies. The structural study exposed that the complex consists of the penta-coordinated double μ1.1-acetato-bridged dinuclear units of Cu­(II), and it is a centrosymmetric dimer in which the center of inversion lies at the midpoint of two Cu­(II) ions. Hirshfeld surface and DFT studies pointed out the probable potentiality of the crystal in prospective binding with the protein. This was experimentally verified by carrying out the binding interaction studies against bovine serum albumin (BSA) protein using various spectroscopic methods. It was observed that the copper­(II) complex could strongly bind to BSA and could quench the intrinsic fluorescence of BSA. Further, the studied complex was appraised for cell viability studies against SiHa cancer cells. It is observed that cell viability increases with time, demonstrating the biocompatible nature of the complex.

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Herein, we report a new Cu(II) complex [Cu(L)(2,2′‐bipy)](ClO4) obtained from a N,N,O donor Schiff base ligand, 2‐methoxy‐6‐((piperidin‐2‐ylmethylimino)methyl)phenol (HL), and 2,2′‐bipyridine. The title complex has been characterized using FTIR, electronic (UV–Vis), electrospray ionization mass spectrometry (ESI‐MS), and single‐crystal X‐ray studies. The crystallographic studies support the chemical formula, [Cu(L)(2,2′‐bipy)](ClO4), where the metal is coordinated by the deprotonated ligand L through N,N,O atoms and by a 2,2′‐bipy molecule chelating through the N donors. Thus, the studied complex attains penta‐coordinated distorted square pyramidal geometry with ON4 atomic environment. The existence of various non‐covalent interactions such as van der Waals, hydrogen bonding, and hydrophobic interactions that are very common in protein–small molecule interaction has been identified in the present complex from Hirshfeld surface analysis. This has provoked us to examine the nature of interactions of the studied complex with DNA and BSA protein by combined theoretical and experimental approaches. The experimental results reveal the strong binding ability of the complex to CT‐DNA by the mode of partial intercalation and to BSA by the hydrophobic manner. Apart from this, the molecular docking methodology that is used as theoretical tool in the present study also supports the binding ability and binding site of the complex inside the DNA and BSA protein. Moreover, cytotoxicity of the complex has been checked against SiHa cancer cell representing the biocompatibility of the complex and signifying its use as biomaterial transplant.

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