Injectable and self-healing dual crosslinked gelatin/kappa-carrageenan methacryloyl hybrid hydrogels via host-guest supramolecular interaction for wound healing

Injectable hydrogels based on natural polymers have shown great potential for various tissue engineering applications, such as wound healing. However, poor mechanical properties and weak self-healing ability are still major challenges. In this work, we introduce a host-guest (HG) supramolecular interaction between acrylate-β-cyclodextrin (Ac-β-CD) conjugated on methacrylated kappa-carrageenan (MA-κ-CA) and aromatic residues on gelatin to provide self-healing characteristics. We synthesize an MA-κ-CA to conjugate Ac-β-CD and fabricate dual crosslinked hybrid hydrogels with gelatin to mimic the native extracellular matrix (ECM). The dual crosslinking occurs on the MA-κ-CA backbone through the addition of KCl and photocrosslinking process, which enhances mechanical strength and stability. The hybrid hydrogels exhibit shear-thinning, self-healing, and injectable behavior, which apply easily under a minimally invasive manner and contribute to shear stress during the injection. In-vitro studies indicate enhanced cell viability. Furthermore, scratch assays are performed to examine cell migration and cell-cell interaction. It is envisioned that the combination of self-healing and injectable dual crosslinked hybrid hydrogels with HG interactions display a promising and functional biomaterial platform for wound healing applications.

Synthesis and investigation of the properties of novel azocalix[4]arenes

The azocalix[4]arenes molecules such as methylphenylazocalix[4]aren (MPcalix[4]) and methoxyphenylazocalix[4]aren (MOPcalix[4]) have been synthesized and characterized by experimental FT-IR and (1)H NMR spectral analyses. The fundamental vibrational transitions have been addressed by experimental FT-IR (4000-400 cm(-1)) technique and density functional theory (DFT) employing B3LYP level with the 6-31G(d) and 6-311G(d,p) basis sets. The (1)H NMR spectra of the studied compounds have been recorded in chloroform, and compared with computed data obtained by using gauge including atomic orbital (GIAO) method. Furthermore, thermodynamic properties (heat capacity, entropy, and enthalpy changes) and frontier molecular orbitals of the molecules in the ground state have been calculated by using the same method and basis sets. The non-linear optical properties such as the first order hyperpolarizability (β0), related properties (α0 and Δα) are also computed. Information about the charge density distribution of the molecules and its chemical reactivity has been studied by mapping molecular electrostatic potential surface (MEPs). The scaled vibrational frequency values have been compared with experimental FT-IR spectroscopic data. The correlations between the observed and calculated frequencies are in good agreement with each other as well as the correlation of NMR data. The linear polarizability and first hyperpolarizability of the studied molecules indicate that the compounds are a good candidate of nonlinear optical materials.

Synthesis and DFT calculation of a novel 5,17-di(2-antracenylazo)-25,27-di(ethoxycarbonylmethoxy)-26,28-dihydroxycalix[4]arene

In this study, 5,17-di(2-antracenylazo)-25,27-di(ethoxycarbonylmethoxy)-26,28-dihydroxycalix[4]arene has been synthesized from 2-aminoantracene and 25,27-dihydroxy-26,28-diethylacetate calix[4]arene. In order to identify the molecular structure and vibrational features of the prepared azocalix[4]arene, FT-IR and (1)H NMR spectral data have been used. FT-IR spectrum of the studied molecule is recorded in the region 4000-400 cm(-1). (1)H NMR spectrum is recorded for 0.1-0.2 M solutions in DMSO-d6 solution. The molecular geometry, infrared spectrum are calculated by the density functional method employing B3LYP level with different basis sets, including 6-31G(d) and LanL2DZ. The chemical shifts calculation for (1)H NMR of the title molecule is calculated by using by Gauge-Invariant Atomic Orbital method by utilizing the same basis sets. The total density of state, the partial density of state and the overlap population density of state diagram analysis are done via GaussSum 3.0 program. Frontier molecular orbital (HOMO-LUMO) and molecular electrostatic potential surface on the title molecule are carried out for various intramolecular interactions that are responsible for the stabilization of the molecule. The experimental results and theoretical calculations have been compared, and they are found to be in good agreement.