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A novel nano-hydroxyapatite (HA)/chitosan composite scaffold with high porosity was developed. The nano-HA particles were made in situ through a chemical method and dispersed well on the porous scaffold. They bound to the chitosan scaffolds very well. This method prevents the migration of nano-HA particles into surrounding tissues to a certain extent. The morphologies, components, and biocompatibility of the composite scaffolds were investigated. Scanning electron microscopy, porosity measurement, thermogravimetric analysis, X-ray diffraction, X-ray photoelectron spectroscopy, and Fourier transformed infrared spectroscopy were used to analyze the physical and chemical properties of the composite scaffolds. The biocompatibility was assessed by examining the proliferation and morphology of MC 3T3-E1 cells seeded on the scaffolds. The composite scaffolds showed better biocompatibility than pure chitosan scaffolds. The results suggest that the newly developed nano-HA/chitosan composite scaffolds may serve as a good three-dimensional substrate for cell attachment and migration in bone tissue engineering.

The growth of microbes on textiles during use and storage negatively affects the wearer as well as the textile itself. The detrimental effects can be controlled by durable antimicrobial finishing of the textile using broad-spectrum biocides or by incorporating the biocide into synthetic fibers during extrusion. Consumers' attitude towards hygiene and active lifestyle has created a rapidly increasing market for antimicrobial textiles, which in turn has stimulated intensive research and development. This article reviews the requirements for antimicrobial finishing, qualitative and quantitative evaluations of antimicrobial efficacy, the application methods of antimicrobial agents and some of the most recent developments in antimicrobial treatments of textiles using various active agents such as silver, quaternary ammonium salts, polyhexamethylene biguanide, triclosan, chitosan, dyes and regenerable N-halamine compounds and peroxyacids. Examples of commercial antimicrobial products are presented to illustrate the active agents used and their finishing methods.

Electrospinning is an economical and relatively simple method to produce continuous and uniform nanofibers from almost any synthetic and many natural polymers. Because of the high specific surface area, tunable pore size, and flexibility, the nanofibrous membranes are finding an increasingly wide range of applications. Some particular attention has been devoted to antibacterial nanofibers for applications such as wound dressings. A variety of biocides, e.g., antibiotics, quaternary ammonium salts, triclosan, biguanides, (silver, titanium dioxide, and zinc oxide) nanoparticles and chitosan have been incorporated by various techniques into nanofibers that exhibit strong antibacterial activity in standard assays. However, the small diameters of the nanofibers also mean that the incorporated biocides are often burst released once the materials are submerged in an aqueous solution. Nevertheless, several strategies, such as coresheath structure of the nanofiber, covalent bonding of the biocide on the fiber surface and adsorption of the biocide in nanostructures, can be utilized to sustain the release over several days. This review summarizes recent development in the fabrication of antibacterial nanofibers, the release profiles of the biocides and their applications in in vivo systems.

In this study, a series of nanofibrous membranes were prepared from cellulose acetate (CA) and polyester urethane (PEU) using coelectrospinning or blend-electrospinning. The drug release, in vitro antimicrobial activity and in vivo wound healing performance of the nanofiber membranes were evaluated for use as wound dressings. To prevent common clinical infections, an antimicrobial agent, polyhexamethylene biguanide (PHMB) was incorporated into the electrospun fibers. The presence of CA in the nanofiber membrane improved its hydrophilicity and permeability to air and moisture. CA fibers became slightly swollen upon contacting with liquid phase. CA not only increased the liquid uptake but also created a moist environment for the wound, which accelerated wound recovery. PHMB release dynamics of the membranes was controlled by the structure and component ratios of the membranes. The lower ratio of CA: PEU helped to preserve the physical and thermal properties of the membranes, and also reduced the burst release effectively and slowed down diffusion of PHMB during in vitro tests. The controlled-diffusion membranes exerted long-term antimicrobial effect for wound healing.

In the past 30 years, researchers have worked to reduce the size of ordinary three-dimensional (3D) materials into 1D or 2D materials in order to obtain new properties and applications...

Chitosan, a natural polysaccharide that has excellent biocompatibility and biodegradability, can be used as nerve conduit material. The purpose of this work was to study the ability of chitosan and some chitosan-derived materials to facilitate nerve cell attachment, differentiation and growth. The biomaterials studied were chitosan, poly-L-lysine-blended chitosan (CP), collagen-blended chitosan (CC) and albumin-blended chitosan (CA), with collagen control material. Culture of PC12 cells and fetal mouse cerebral cortex (FMCC) cells on these biomaterials was used to evaluate their nerve cell affinity. The composite materials, including CP, CC and CA, had significantly improved nerve cell affinity compared to chitosan, as established by increasing attachment, differentiation and growth of PC12 cells. FMCC cells could also grow better on composite materials than on chitosan. CP exhibited the best nerve cell affinity among these three types of composite material. CP is an even better material in promoting neurite outgrowth than collagen, a substrate that is widely used in tissue engineering, suggesting that CP is a promising candidate material for nerve regeneration.

The aim was to compare the early outcomes between thoracoscopic and laparoscopic esophagectomy (TLE) and open three-field esophagectomy for esophageal cancer. We retrospectively analyzed clinical data from 96 patients with esophageal cancer who underwent TLE, and 78 patients who underwent open three-field esophagectomy from March 2008 to September 2010. All the operations were successful. There was no significant difference between TLE and open three-field esophagectomy with regard to the number of lymph nodes procured (17.75±5.56 vs. 18.03±6.20, P>0.05), complications (32.3% vs. 46.2%, P>0.05), and operative mortality (2.1% vs. 3.8%, P>0.05). However, hospital stay was significantly shorter in the TLE group than the open esophagectomy group (12.64±8.82 vs. 17.53±6.40 days, P<0.01), and the TLE group had significantly less blood loss (346.68±41.13 vs. 519.26±47.74 ml, P<0.01). This showed that TLE for esophageal cancer offers results as good as or better than those with open three-field esophagectomy.