Novel insights into seasonal airborne bacterial interactions and potential threats to human health in a northwest city, China.

Bioaerosols significantly influence air quality and human health. This study investigated the diversity, structure, and interaction of bacterial communities in particulate matter (PM) across four seasons in Xi'an. The results revealed that operational taxonomic units (OTUs) were the highest in autumn, reaching levels comparable to those in winter, but were 3.

Grafting of CAG peptides and (polyethylene glycol) on unsaturated polyurethane films to promote selective adhesion and migration of urethral epithelial cells.

Selective adhesion and migration of urethral epithelial cells (HUCs) over fibroblasts (FIBs) are very important in the reconstruction of the urethral epithelial layer and prevention of ureteral scarring and stenosis. In this study, unsaturated polyurethane (PPFU-CO-SS) films were co-grafted with a cell-resisting poly(ethylene glycol) (PEG) layer and HUC-selective Cys-Ala-Gly (CAG) peptides, whose physicochemical changes were confirmed by X-ray photon spectroscopy, fluorescence spectroscopy and water contact angle measurements. The adhesion and activation of platelets on the PEG/CAG grafted surface were significantly reduced compared to those on the PPFU-CO-SS, resulting in a similar status as that on a PEG-grafted surface.

Large fuzzy biodegradable polyester microspheres with dopamine deposition enhance cell adhesion and bone regeneration in vivo.

The biodegradable polymer microparticles with different surface morphology and chemical compositions may influence significantly the behaviors of cells, and thereby further the performance of tissue regeneration in vivo. In this study, multi-stage hierarchical textures of poly(D,L-lactic-co-glycolide) (PLGA)/PLGA-b-PEG (poly(ethylene glycol)) microspheres with a diameter as large as 50-100 μm are fabricated based on interfacial instability of an emulsion. The obtained fuzzy structures on the microspheres are sensitive to annealing, which are changed gradually to a smooth one after treatment at 37 °C for 6 d or 80 °C for 1 h.

A tarsus construct of a novel branched polyethylene with good elasticity for eyelid reconstruction .

Branched polyethylene (B-PE) elastomer was investigated for its potential medical application as a tarsus construct. The results showed that the B-PE and processed B-PE films or scaffolds did not exhibit noticeable cytotoxicity to the NIH3T3 fibroblasts and human vascular endothelial cells (ECs). The B-PE scaffolds with a pore size of 280-480 µm were prepared by using a gelatin porogen-leaching method.

Adsorption of serum proteins on titania nanotubes and its role on regulating adhesion and migration of mesenchymal stem cells.

Migration and differentiation of bone marrow-derived mesenchymal stem cells (BMSCs) is an important biological process in tissue regeneration. Nanostructured titanium materials are believed to play a fundamental role in dental and orthopedic applications. However, the protein adsorption on nanostructured titanium materials and its correlation with the subsequent cell behaviors have not been studied.

Unsaturated polyurethane films grafted with enantiomeric polylysine promotes macrophage polarization to a M2 phenotype through PI3K/Akt1/mTOR axis.

The immune system responds immediately to tissue trauma and to biomaterial implants under the participation of M1/M2 macrophages polarization. The surface properties of biomaterials can significantly influence the tissue repair progress through modulating the macrophage functions. In this study, the surface of poly(propylene fumarate) polyurethane films (PPFU) is grafted with a same density of enantiomeric poly-l-lysine (PPFU-g-PLL) and poly-d-lysine (PPFU-g-PDL), leading to a similar level of enhanced surface wettability for the PPFU-g-PLL and PPFU-g-PDL.

Methylcobalamin-Loaded PLCL Conduits Facilitate the Peripheral Nerve Regeneration.

The feasible fabrication of nerve guidance conduits (NGCs) with good biological performance is important for translation in clinics. In this study, poly(d,l-lactide-co-caprolactone) (PLCL) films loaded with various amounts (wt; 5%, 15%, 25%) of methylcobalamin (MeCbl) are prepared, and are further rolled and sutured to obtain MeCbl-loaded NGCs. The MeCbl can be released in a sustainable manner up to 21 days.

Biodegradable Anisotropic Microparticles for Stepwise Cell Adhesion and Preparation of Janus Cell Microparticles.

The biomimetic anisotropic particles have different physicochemical properties on the opposite two sides, enabling diverse applications in emulsion, photonic display, and diagnosis. However, the traditional anisotropic particles have a very small size, ranging from submicrons to a few microns. The design and fabrication of anisotropic macron-sized particles with new structures and properties is still challenging.

The External Performance Appraisal of China Energy Regulation: An Empirical Study Using a TOPSIS Method Based on Entropy Weight and Mahalanobis Distance.

In China's industrialization process, the effective regulation of energy and environment can promote the positive externality of energy consumption while reducing negative externality, which is an important means for realizing the sustainable development of an economic society. The study puts forward an improved technique for order preference by similarity to an ideal solution based on entropy weight and Mahalanobis distance (briefly referred as E-M-TOPSIS). The performance of the approach was verified to be satisfactory.

Preparation of photo-responsive poly(ethylene glycol) microparticles and their influence on cell viability.

Intelligent colloidal particles have been widely used as carriers for delivery of bioactive molecules due to the ability of controlled release. However, attention is mainly paid to the effects of their payloads, whereas the impacts of carriers are largely ignored. In this study, photo-responsive polyethylene glycol (PEG) microparticles were fabricated by using 8-arm-PEG with terminal amine groups (8-arm-PEG-NH) and a photo-cleavable cross-linker.

Fabrication of polyurethane microcapsules with different shapes and their influence on cellular internalization.

The shape of particles is recognized as an important parameter to influence their interactions with cells. In this study, spherical and discal polyurethane microcapsules were prepared via an adsorption and crosslinking method on the templates with corresponding shapes in organic solvent. Both types of capsules could be well dispersed in aqueous medium and maintain their original shapes.

Non-covalent assembly of poly(allylamine hydrochloride)/triethylamine microcapsules with ionic strength-responsiveness and auto-fluorescence.

Ionic strength-responsive microcapsules with auto-fluorescence were fabricated by incubation of poly(allylamine hydrochloride) (PAH)-doped CaCO particles in triethylamine (EtN), followed by core removal using HCl. Based on the combination of hydrophobic interaction and hydrogen bonding, PAH and EtN formed a complex with a molar ratio of 3:1 (repeating unit of PAH: EtN). The as-prepared capsules showed extraordinary stability against 1M HCl, 1M NaOH and 6M urea solutions, and could swell or shrink reversibly in response to the ionic strength.

Synthesis of Chiral Oligomer-Grafted Biodegradable Polyurethanes and Their Chiral-Dependent Influence on Bone Marrow Stem Cell Behaviors.

Chirality is one of the most fascinating and ubiquitous features in nature, especially in biological systems. The effects of chiral surfaces, especially in combination with degradable materials of good biocompatibility, on stem cell behaviors has not yet been tackled. In this communication, the chiral monomers N-acryloyl-l(d)-valine (l(d)-AV) are synthesized and are polymerized to obtain chiral (l(d)-PAV-SH) oligomers, which are covalently immobilized onto electron-deficient poly(propylene fumarate) polyurethane (PPFU) via Michael addition.

Aligned PLLA nanofibrous scaffolds coated with graphene oxide for promoting neural cell growth.

Unlabelled: The graphene oxide (GO) has attracted tremendous attention in biomedical fields. In order to combine the unique physicochemical properties of GO nanosheets with topological structure of aligned nanofibrous scaffolds for nerve regeneration, the GO nanosheets were coated onto aligned and aminolyzed poly-l-lactide (PLLA) nanofibrous scaffolds. Scanning electronic microscopy (SEM) and atomic force microscopy (AFM) revealed that the surface of aligned PLLA nanofibers after being coated with GO became rougher than those of the aligned PLLA and aminolyzed PLLA nanofibrous scaffolds.