SIKVAV-Modified Chitosan Hydrogel as a Skin Substitutes for Wound Closure in Mice.

Skin wound healing is a complex and dynamic process that involves angiogenesis and growth factor secretion. Newly formed vessels can provide nutrition and oxygen for skin wound healing. Growth factors in skin wounds are important for keratinocytes and fibroblasts proliferation, epithelialization, extracellular matrix remodeling, and angiogenesis, which accelerate skin wound healing. Therefore, treatment strategies that enhance angiogenesis and growth factors secretion in skin wounds can accelerate skin wound healing. This study investigated the effects of a SIKVAV (Ser-Ile-Lys-Val-Ala-Val) peptide-modified chitosan hydrogel on skin wound healing. Hematoxylin and eosin (H&E) staining demonstrated that the SIKVAV-modified chitosan hydrogel accelerated the re-epithelialization of wounds compared with that seen in the negative and positive controls. Masson's trichrome staining showed that more collagen fibers were deposited in the skin wounds treated with the SIKVAV-modified chitosan hydrogel than in the negative and positive controls. Immunohistochemistry assays demonstrated that more myofibroblasts were deposited and more angiogenesis occurred in skin wounds treated with the SIKVAV-modified chitosan hydrogel than in the negative and positive controls. In addition, ELISA assays showed that the SIKVAV-modified chitosan hydrogels promoted the secretion of growth factors in skin wounds. Taken together, these results suggest that the SIKVAV-modified chitosan hydrogel has the potential to be developed as synthesized biomaterials for the treatment of skin wounds.

Fe/Mn multilayer nanowires as dual mode T1 -T2 magnetic resonance imaging contrast agents.

To overcome the negative contrast limitations, and to improve the sensitivity of the magnetic resonance signals, the mesoporous silica coated Fe/Mn multilayered nanowires (NWs) were used as a T1 -T2 dual-mode contrast agents (CAs). The single component Fe and Mn NWs, and Fe/Mn multilayer NWs were synthesized by electrodeposition in the homemade anodic aluminum oxide (AAO) templates with the aperture of about 30 nm. The structural characterization and morphology of single component and multisegmented NWs was done by X-ray diffraction and transmission electron microscopy. The elemental composition of Fe/Mn multilayerd NWs was confirmed by energy-dispersive X-ray and energy-dispersive spectrometer. Vibrating sample magnetometer was used to test the magnetic properties, and 1.5 T magnetic resonance imaging (MRI) scanner was used to measure the relaxation efficiency. Importantly, the MRI study indicated that the Fe/Mn multilayer NWs showed a significant T1 -T2 imaging effect, and have longitudinal relaxivity (r1 ) value, that is, 1.25 ± 0.0329 × 10-4 µM-1 s-1 and transverse relaxivity (r2 ), that is, 5.13 ± 0.123 × 10-4 µM-1 s-1 , which was two times of r1 value (0.654 ± 0.00899 × 10-4 µM-1 s-1 ) of Mn NWs, and r2 value (2.96 ± 0.0415 × 10-4 µM-1 s-1 ) of Fe NWs. Hence, Fe/Mn multilayer NWs have potential to be used as T1 -T2 dual-mode CAs.

Autografts vs Synthetics for Cruciate Ligament Reconstruction: A Systematic Review and Meta-Analysis.

To describe the outcomes of autografts and synthetics in anterior cruciate ligament (ACL) and posterior cruciate ligament (PCL) reconstruction with respect to instrumented laxity measurements, patient-reported outcome scores, complications, and graft failure risk. We searched PubMed, Cochrane Library, and EMBASE for published randomized controlled trials (RCT) and case controlled trials (CCTs) to compare the outcomes of the autografts versus synthetics after cruciate ligament reconstruction. Data analyses were performed using Cochrane Collaboration RevMan 5.0. Nine studies were identified from the literature review. Of these studies, three studies compared the results of bone-patellar tendon-bone (BPTB) and ligament augmentation and reconstruction system (LARS), while six studies compared the results of four-strand hamstring tendon graft (4SHG) and LARS. The comparative study showed no difference in Lysholm score and failure risk between autografts and synthetics. The combined results of the meta-analysis indicated that there was a significantly lower rate of side-to-side difference > 3 mm (Odds Ratio [OR] 2.46, 95% confidence intervals [CI] 1.44-4.22, P = 0.001), overall IKDC (OR 0.40, 95% CI 0.19-0.83, P = 0.01), complications (OR 2.54, 95% CI 1.26-5.14, P = 0.009), and Tegner score (OR -0.31, 95% CI -0.52-0.10, P = 0.004) in the synthetics group than in the autografts group. This systematic review comparing long-term outcomes after cruciate ligament reconstruction with either autograft or synthetics suggests no significant differences in failure risk. Autografts were inferior to synthetics with respect to restoring knee joint stability and patient-reported outcome scores, and were also associated with more postoperative complications.