Extraction and composition characterisation of amino acids from tung meal

<p>The most desirable content of amino acids (AAs) in the extracted products from tung (<i>Aleurites fordii</i>) meal was 93.88%, which was obtained from shelled tung meal at a hydrolysis temperature of 45°C and a isoelectric precipitation pH value of 4.4. Furthermore, the cytotoxic activity of extracted AAs was also evaluated by MTT assay. Antioxidant activity of extracted AAs was also measured by the DPPH assay. As a result, the high yield of extracted AAs exhibited so low cytotoxic and high antioxidant activity that had the potential use as a functional ingredient.</p

Supercooling Self-Assembly of Magnetic Shelled Core/Shell Supraparticles

Molecular self-assembly has emerged as a powerful technique for controlling the structure and properties of core/shell structured supraparticles. However, drug-loading capacities and therapeutic effects of self-assembled magnetic core/shell nanocarriers with magnetic nanoparticles in the core are limited by the intervention of the outer organic or inorganic shell, the aggregation of superparamagnetic nanoparticles, the narrowed inner cavity, etc. Here, we present a self-assembly approach based on rebalancing hydrogen bonds between components under a supercooling process to form a new core/shell nanoscale supraparticle with magnetic nanoparticles as the shell and a polysaccharide as a core. Compared with conventional iron oxide nanoparticles, this magnetic shelled core/shell nanoparticle possesses an optimized inner cavity and a loss-free outer magnetic property. Furthermore, we find that the drug-loaded magnetic shelled nanocarriers showed interesting <i>in vitro</i> release behaviors at different pH conditions, including “swelling-broken”, “dissociating-broken”, and “bursting-broken” modes. Our experiments demonstrate the novel design of the multifunctional hybrid nanostructure and provide a considerable potential for the biomedical applications

Shape Memory Actuation of Janus Nanoparticles with Amphipathic Cross-Linked Network

Preparation of nanoscale Janus particles that can respond to external stimulation and, at the same time, be prepared using an easily achievable method presents a significant challenge. Here, we have demonstrated the shape memory of Janus nanoparticles (SMJNPs) with a multifunctional combination of Janus nanostructure and a shape memory effect, composed of a well-defined amphipathic sucrose-poly­(ε-caprolactone) cross-linked network. A sudden negative pressure method was first used to prepare the Janus-shaped nanoparticles (temporary shape), which can switch their shape and wettability. The Janus-shaped nanoparticle is an amphipathic structure composed of hydrophilic and hydrophobic parts. Moreover, in response to temperature, the nanoparticle can recover their nanosphere state via a shape memory process. The novel Janus nanoparticles with the shape memory property also show a great potential for application such as drug delivery

Bioadhesive Microporous Architectures by Self-Assembling Polydopamine Microcapsules for Biomedical Applications

Bioadhesive microporous architectures that mimic the functions of a natural extracellular matrix (ECM) were prepared by self-assembling polydopamine (PDA) microcapsules, which not only favor cell adhesion and growth, but also facilitate growth factor immobilization and release. PDA-coated polystyrene (PS) microspheres are synthesized by polymerization of dopamine on sulfonated PS microspheres and then assembled using positively charged chitosan (CHI) layers as link agents. After the PS core templates were removed, microporous architectures composed of PDA microcapsules were obtained. The produced microporous PDA architectures have a high capability of adsorbing BMP-2 and realize the sustained release of BMP-2. More importantly, the bioadhesive micro architecture and its immobilized BMP-2 synergistically enhance the activity and osteogenetic differentiation of bone marrow mesenchymal stem cells (BMSCs). Both supercell adhesion and BMP-2 immobilization ability of these architectures are attributed to the intrinsic adhesive nature of PDA and the porous architectures via the assembly of PDA microcapsules. The bioadhesive microporous PDA architectures with both cell affinitive and GF release features have a great potential to mimic natural ECM for modifying various medical devices in the fields of tissue engineering and regenerative medicine

Enhanced Repairing of Critical-Sized Calvarial Bone Defects by Mussel-Inspired Calcium Phosphate Cement

The goal of this study is to investigate the biological response of mussel-inspired calcium phosphate cement (CPC) in vivo. Polydopamine (PDA), which is analogous to that of mussel adhesive proteins, was added in CPC. PDA-CPC was implanted into the femur, muscle, and critical-sized calvarial bone defects of rabbits. Histomorphometry of the sequential fluorescence sections showed that PDA-CPC was capable of forming more newborn bone than the control-CPC. More new bone, bone marrow cavity, and blood vessel were observed in PDA-CPC than in the control-CPC in decalcified and undecalcified histological sections. Necrosis bone was not observed in PDA-CPC, whereas it appeared in the control-CPC after 2 weeks. The histological sections in muscle witnessed that there was more ingrowth of collagen in PDA-CPC than that in the control-CPC. There were no significantly difference in the number of leukocyte between PDA-CPC and the control-CPC in blood. It was confirmed that the addition of PDA enhanced the bone repairing ability and biocompatibility of PDA-CPC. Push-out testing indicated that PDA increased the bonding strength between PDA-CPC and host bone in the early stage. These present results indicated that PDA-CPC might be one potential bone graft with gratifying biocompatibility and enhanced bone repairing