Porous and nonporous silk fibroin (SF) membranes wrapping for Achilles tendon (AT) repair: Which one is a better choice?

Two types of silk fibroin (SF) membranes were developed for tendon repair: porous and nonporous SF membranes. The objective of this study was to compare the efficiency of these two films according to the ability of tendon regeneration using a rat Achilles tendon (AT) rupture suture wrapping model. The in vitro tests were conducted, and theSF membranes were proved to be with ultimate-biodegradability, good-biocompatibility and without toxicity. In vivo, 12 Sprague Dawley rats were used to create a rat AT rupture suture model wrapped by SF membranes. They were randomly divided into six groups. The results revealed that the nonporous SF membrane wrapping group was shown to reduce the inflammatory effect and induce the proliferation of fibroblast-like cells at one week and four weeks post-operatively. After four weeks, the nonporous SF membrane wrapping group exhibited more organized collagen structures and had increased expression of tendon repair proteins. Hence, our nonporous SF membrane improved the efficacy of tendon regeneration by decreasing inflammatory cells, growing fibroblast-like cells, and promoting extracellular matrix production. Nonporous SF membrane can, therefore, be regarded as a better functional membrane for tendon repair. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part B: 00B: 000-000, 2018. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 107B: 733-740, 2019.

Volunteer study and serum protein profiling to understand inflammatory response induced by Satsuma mandarin.

It has been observed that consumption of a certain amount of Satsuma, lychee, and longan often caused a symptom characterized by dry or sore throat, gum swelling and even mouth ulcer, which significantly impaired the life quality of a large population. We define the adverse reaction to Satsuma as Satsuma-induced syndrome (SIS). Volunteers were assigned to oral Satsuma challenge in an open manner. The results showed that SIS was characterized with symptoms affecting the throat, oral cavity, face, gastrointestinal system and eye either individually or in combination. A comparative proteomic study was performed to investigate the differences of serum proteins in the Post-SC (after Satsuma challenge) and Pre-SC (before Satsuma challenge) serum samples of 15 volunteers with severe SIS. Ten proteins were identified to be differentially expressed (P<0.05). Of these, levels of complement component C9 precursor were elevated significantly in the Post-SC serum samples and were further verified by enzyme-linked immunosorbent assay, indicating that the complement system may be activated and plays a significant role in inflammatory response. Meanwhile, serum samples were subjected to immobilized metal affinity capture (IMAC3) protein chip surfaces and tested by surface-enhanced laser desorption/ionization-time of flight-mass spectrometry. The data were analyzed by Ciphergen ProteinChip Software. A diagnostic model was constructed to discriminate the SIS from normal samples, using principal component analysis. A total of 50 detected biomarkers were found to be different with statistical significance (P<0.05). The multivariate logistic analysis demonstrates a complete distinction between the two groups. Our findings suggest that these assays may provide potential biomarkers for the diagnosis of SIS.

Antibacterial multilayer films fabricated by LBL immobilizing lysozyme and HTCC on nanofibrous mats.

Cellulose acetate nanofibrous mats were prepared by electrospunning technique. Positively charged and negatively charged composites were alternately deposited on negatively charged CA mats via layer-by-layer self-assembly technique. The morphology and inhibition rate of samples were investigated by regulating number of deposition bilayers and composition of outermost layer. Field emission scanning electron microscopy images indicated that the average diameter of fibers was increased with increasing the number of coating bilayers. Additionally, the catalytic activity of immobilized LY was measured and results showed "layer-by-layer alternative oscillation" phenomenon. The results of antibacterial assay indicated that (LY-HTCC/ALG)(10.5) films coating had the best inhibitory effect.

Cytotoxicity and antibacterial ability of scaffolds immobilized by polysaccharide/layered silicate composites.

Chitosan and pectin/organic rectorite (OREC) were initially deposited on the surface of cellulose acetate electrospun nanofibers by a layer-by-layer (LBL) technique to fabricate scaffolds for bacterial inhibition, and the cytotoxicity of the LBL structured scaffolds was also investigated. A couple of opposite charged material, pectin and OREC, were firstly used to fabricate the intercalated composites. The intercalated structure was determined by selected area electron diffraction. Field-emission scanning electron microscope, X-ray diffraction and X-ray photoelectron spectroscopy were applied for the characterization of LBL structured nanofibrous scaffolds. Antibacterial assay results showed that the diameters of the inhibition zone increased from 7.6 to 15.8 mm for Escherichia coli, as well as from 7.4 to 14.2 mm for Staphylococcus aureus. Finally, human epidermal (EP) cells grew well on the LBL films coating. These novel scaffolds could be an ideal candidate for wound dressings and food packaging.