Design and optimization of a biodegradable porous zein conduit using microtubes as a guide for rat sciatic nerve defect repair.

Various degradable biomaterials have been used to bridge injured peripheral nerve defect; however, drawbacks such as poor mechanical properties, inappropriate degradation rate, and toxic degradation products continue to limit the application of them in nerve repair. Considering the unique properties of zein, such as its biocompatibility, biodegradability and ease of fabrication, we report the use of zein conduits to repair injured rat sciatic nerves with a 10-mm defect. Three-dimensional zein conduits were designed with/without pores, and with/without microtubes including in the lumen of conduits. Zein conduit with microtubes yielded satisfactory results in sciatic function index (SFI), proximal compound muscle action potentials, density of myelinated nerve fibres and myelin thickness, which were not inferior to autograft but slightly superior to the hollow conduit at the 4th month post-implantation. The conduits degraded almost completely within two months, which was shorter than the suggested period of four months. Thus, the use of a porous conduit with microtubes inside as the guidance may play important roles in successful repair. Notably, the regulatory body will more likely approve designs employing a single component, such as the natural polymer zein.

Hydrothermal syntheses and characterizations of two novel frameworks constructed from polyoxometalates, metals and organic units.

Two novel compounds have been hydrothermally synthesized and characterized by IR spectra and single crystal X-ray diffraction analyses. Crystal structure analyses reveal that and exhibit novel 2-D framework structures constructed from tungsten polyoxoanions, metal ions and 4,4-byp units, respectively.

First examples of extended structures based on {PMo(12)Sb(2)O(40)} polyoxoanions.

Three novel heteropolyanions [PMo(12)Sb(2)O(40)][Cu(enMe)(2)].4H(2)O (), [PMo(12)Sb(2)O(40)][Ni(enMe)(2)].4H(2)O (2) and [PMo(12)Sb(2)O(40)][Cu(en)(2)].H(3)O.H(2)O (3) (enMe = 1,2-diaminopropane, en = ethylene diamine) have been synthesized and characterized by IR spectroscopy, X-ray photoelectron spectroscopy (XPS), thermogravimetric analyses and elemental analyses. Single-crystal X-ray diffraction analyses reveal that these three compounds represent the first examples of compounds based on the novel polyoxoanion {PMo(12)Sb(2)O(40)} and different transition metal coordination complexes. 1 and 2 are isostructural and both exhibit novel 1-D structures. In contrast to 1 and 2, 3 exhibits a substantially distinct novel 1-D structure. In addition, 3 is the first example of an extended structure constructed from polyoxoanions and Cu(+) transition metal coordination complexes.

Synthesis and characterization of a novel POM compound containing two different layers stacked alternately.

A novel POM compound containing the first Sb bicapped Keggin anion {SiMo(12)O(40)Sb(2)} and two different layers constructed from these anions stacked alternately has already been hydrothermally synthesized.