: The unpolarized absorption and circular dichroism spectra of the fundamental vibrational transitions of the chiral molecule, 4-methyl-2-oxetanone, are calculated ab initio. Harmonic force fields are obtained using Density Functional Theory (DFT), MP2, and SCF methodologies and a 5S4P2D/3S2P (TZ2P) basis set. DFT calculations use the Local Spin Density Approximation (LSDA), BLYP, and Becke3LYP (B3LYP) density functionals. Mid-IR spectra predicted using LSDA, BLYP, and B3LYP force fields are of significantly different quality, the B3LYP force field yielding spectra in clearly superior, and overall excellent, agreement with experiment. The MP2 force field yields spectra in slightly worse agreement with experiment than the B3LYP force field. The SCF force field yields spectra in poor agreement with experiment.The basis set dependence of B3LYP force fields is also explored: the 6-31G* and TZ2P basis sets give very similar results while the 3-21G basis set yields spectra in substantially worse agreements with experiment. jg

Ab initio calculation of vibrational absorption and circular dichroism spectra using density functional force fields

In this review, we focus on the very recent developments on the use of the stimuli responsive properties of polymer hydrogels for targeted drug delivery, tissue engineering, and biosensing utilizing their different optoelectronic properties. Besides, the stimuli-responsive hydrogels, the conducting polymer hydrogels are discussed, with specific attention to the energy generation and storage behavior of the xerogel derived from the hydrogel. The electronic and ionic conducting gels have been discussed that have applications in various electronic devices, e.g., organic field effect transistors, soft robotics, ionic skins, and sensors. The properties of polymer hybrid gels containing carbon nanomaterials have been exemplified here giving attention to applications in supercapacitors, dye sensitized solar cells, photocurrent switching, etc. Recent trends in the properties and applications of some natural polymer gels to produce thermal and acoustic insulating materials, drug delivery vehicles, self-healing material, tissue engineering, etc., are discussed. Besides the polymer gels, peptide gels of different dipeptides, tripeptides, oligopeptides, polypeptides, cyclic peptides, etc., are discussed, giving attention mainly to biosensing, bioimaging, and drug delivery applications. The properties of peptide-based hybrid hydrogels with polymers, nanoparticles, nucleotides, fullerene, etc., are discussed, giving specific attention to drug delivery, cell culture, bio-sensing, and bioimaging properties. Thus, the present review delineates, in short, the preparation, properties, and applications of different polymer and peptide hydrogels prepared in the past few years.

A review on recent advances in polymer and peptide hydrogels

Nanocellulose is cellulose in the form of nanostructures, i.e., features not exceeding 100 nm at least in one dimension. These nanostructures include nanofibrils, found in bacterial cellulose; nanofibers, present particularly in electrospun matrices; and nanowhiskers, nanocrystals, nanorods, and nanoballs. These structures can be further assembled into bigger two-dimensional (2D) and three-dimensional (3D) nano-, micro-, and macro-structures, such as nanoplatelets, membranes, films, microparticles, and porous macroscopic matrices. There are four main sources of nanocellulose: bacteria (Gluconacetobacter), plants (trees, shrubs, herbs), algae (Cladophora), and animals (Tunicata). Nanocellulose has emerged for a wide range of industrial, technology, and biomedical applications, namely for adsorption, ultrafiltration, packaging, conservation of historical artifacts, thermal insulation and fire retardation, energy extraction and storage, acoustics, sensorics, controlled drug delivery, and particularly for tissue engineering. Nanocellulose is promising for use in scaffolds for engineering of blood vessels, neural tissue, bone, cartilage, liver, adipose tissue, urethra and dura mater, for repairing connective tissue and congenital heart defects, and for constructing contact lenses and protective barriers. This review is focused on applications of nanocellulose in skin tissue engineering and wound healing as a scaffold for cell growth, for delivering cells into wounds, and as a material for advanced wound dressings coupled with drug delivery, transparency and sensorics. Potential cytotoxicity and immunogenicity of nanocellulose are also discussed.

https://www.mdpi.com/2079-4991/9/2/164/pdf

Versatile Application of Nanocellulose: From Industry to Skin Tissue Engineering and Wound Healing

Natural Polymer-Based Antimicrobial Hydrogels without Synthetic Antibiotics as Wound Dressings

Cellulose, lignin and lignocellulose are important bioresources in the nature. Their effective and environmentally friendly utilization not only reduces dependence on fossil resources but also protects the environment. Recently, a class of novel eco-friendly solvents, ionic liquids, is employed to dissolve and process these bioresources. In this mini-review, we summarized the recent advances of processing and valorization of cellulose, lignin and lignocellulose in ionic liquids. It is expected that this up-to-date survey provides a comprehensive information of this field, and accelerates the development and utilization of the renewable plant biomass resources.

Processing and valorization of cellulose, lignin and lignocellulose using ionic liquids

Facile fabrication of redox/pH dual stimuli responsive cellulose hydrogel.

Durable antibacterial and hydrophobic cotton fabrics utilizing enamine bonds.

Cellulosic sponges with pH responsive wettability for efficient oil-water separation.

Thiol-functionalised cellulose sponges were conveniently synthesised by reacting (2,2,6,6-tetramethylpiperidin-1-yl)oxyl oxidised cellulose nanofibrils (CNF) with (3-mercaptopropyl)-trimethoxysilane (MPTMS) at room temperature. The sponges, whose structures resemble honeycombs, were systematically characterised using Fourier transform infrared spectroscopy, solid-state 13C nuclear magnetic resonance spectroscopy, elemental analysis, scanning electron microscopy, energy-dispersive X-ray spectroscopy and compression tests. It was shown that the sponges could be used to selectively remove Hg2+ from an aqueous solution containing other metal ions and had excellent adsorption capacities of up to 700 mg/g. The sorption isotherm followed the typical Langmuir model and the adsorption kinetics fit a pseudo-second-order model. X-ray photoelectron spectroscopy was applied to confirm that sulfur and oxygen had significant roles in the adsorption of Hg2+. The sponges also showed high reusability after three adsorption–desorption cycles. This paper provides a simple method to prepare highly efficient adsorbents for the adsorption of Hg2+ from aqueous solutions.

Liduo Rong

Papers

Facile fabrication of redox/pH dual stimuli responsive cellulose hydrogel.

Durable antibacterial and hydrophobic cotton fabrics utilizing enamine bonds.

Cellulosic sponges with pH responsive wettability for efficient oil-water separation.

Facile fabrication of thiol-modified cellulose sponges for adsorption of Hg 2+ from aqueous solutions

A light-weight and high-efficacy antibacterial nanocellulose-based sponge via covalent immobilization of gentamicin.