Conductive polymer scaffolds to improve neural recovery

Injuries to the nervous system manifest in various forms ranging from stroke to trauma（i.e.,motor vehicle accidents,combats）to diabetic neuropathy as well as many other neurological diseases.Nerve regeneration remains a complex biological process that is challenging to address clinically.There is no effective medical treatment for central nervous system repair.

Synthesis and Properties of Novel Surface Active Maleic Monomer Containing Phosphate Group

A novel surface active monomer （surfmer） containing poly（ethylene glycol） chain and terminated phosphate group was synthesized. The copolymerization of synthesized surfmer with NVP （N-vinylpyrrolidone） and with NVP and VEP （5-tert-butylperoxy-5-methyl-2-hexene-3-yne monomer） led to formation of corresponding surface-active copolymers. The capability of application of resulted copolymers as surface active macroinitiators of emulsion polymerization of styrene and as components of polymeric scaffolds was investigated.

3D printing of personalized polylactic acid scaffold laden with GelMA/autologous auricle cartilage to promote ear reconstruction

At present,the clinical reconstruction of the auricle usually adopts the strategy of taking autologous costal cartilage.This method has great trauma to patients,poor plasticity and inaccurate shaping.Three-dimensional(3D)printing technology has made a great breakthrough in the clinical application of orthopedic implants.This study explored the combination of 3D printing and tissue engineering to precisely reconstruct the auricle.First,a polylactic acid(PLA)polymer scaffold with a precisely customized patient appearance was fabricated,and then auricle cartilage fragments were loaded into the 3D-printed porous PLA scaffold to promote auricle reconstruction.In vitro,gelatin methacrylamide(GelMA)hydrogels loaded with different sizes of rabbit ear cartilage fragments were studied to assess the regenerative activity of various autologous cartilage fragments.In vivo,rat ear cartilage fragments were placed in an accurately designed porous PLA polymer ear scaffold to promote auricle reconstruction.The results indicated that the chondrocytes in the cartilage fragments could maintain the morphological phenotype in vitro.After three months of implantation observation,it was conducive to promoting the subsequent regeneration of cartilage in vivo.The autologous cartilage fragments combined with 3D printing technology show promising potential in auricle reconstruction.

Halloysite nanotubes loaded with nano silver for the sustained-release of antibacterial polymer nanocomposite scaffolds

It is challenging for antibacterial polymer scaffolds to achieve the drug sustained-release through directly coating or blending.In this work,halloysite nanotubes(HNTs),a natural aluminosilicate nanotube,were utilized as a nano container to load nano silver(Ag)into the lumen through vacuum negativepressure suction&injection and thermal decomposition of silver acetate.Then,the nano Ag loaded HNTs(HNTs@Ag)were introduced to poly-l-lactic acidide)(PLLA)scaffolds prepared by additive manufacturing for the sustained-release of Ag^+.Acting like a’shield’,the tube walls of HNTs not only retarded the erosion of external aqueous solution on internal nano Ag to generate Ag^+but also postponed the generated Ag^+to diffuse outward.The results indicated the PLLA-HNTs@Ag nanocomposite scaffolds achieved a sustained-release of Ag^+over 28 days without obvious initial burst release.Moreover,the scaffolds exhibited a long-lasting antibacterial property without compromising the cytocompatibility.Besides,the degradation properties,biomineralization ability and mechanical properties of the scaffolds were increased.This study suggests the potential application of inorganic nanotubes as drug carrier for the sustained-release of functional polymer nanocomposite scaffolds.

PoreScript:Semi-automated pore size algorithm for scaffold characterization

The scaffold pore size influences many critical physical aspects of tissue engineering,including tissue infiltration,biodegradation rate,and mechanical properties.Manual measurements of pore sizes from scanning electron micrographs using ImageJ/FIJI are commonly used to characterize scaffolds,but these methods are both time-consuming and subject to user bias.Current semi-automated analysis tools are limited by a lack of accessibility or limited sample size in their verification process.The work here describes the development of a new MATLAB algorithm,PoreScript,to address these limitations.The algorithm was verified using three common scaffold fabrication methods(e.g.,salt leaching,gas foaming,emulsion templating)with varying pore sizes and shapes to demonstrate the versatility of this new tool.Our results demonstrate that the pore size characterization using PoreScript is comparable to manual pore size measurements.The PoreScript algorithm was further evaluated to determine the effect of user-input and image parameters(relative image magnification,pixel intensity threshold,and pore structure).Overall,this work validates the accuracy of the PoreScript algorithm across several fabrication methods and provides user-guidance for semi-automated image analysis and increased throughput of scaffold characterization.