Preparation of polyvinyl alcohol/lota-carrageenan scaffolds and its biocompatibility / 中国组织工程研究

BACKGROUND:Polyvinyl alcohol (PVA) hydrogel with similar porous structure and mechanical properties to the natural cartilage is very suitable for the repair of articular cartilage. However, the pure PVA hydrogel after lyophilization wil be accompanied by the shrinkage of the polymer network and the col apse of the pores, leading to the inhomogeneous performance of the material even in the state of re-swel ing. Addition of the active polymer wil increase the cel adhesion ability of PVA hydrogel. OBJECTIVE:To construct PVA/lota-carrageenan (l-CA) composite materials with different mass fractions of l-CA and evaluate the biocompatibility with vascular endothelial cel s. METHODS:PVA/l-CA composite films with different contents of l-CA were fabricated and then co-cultured with vascular endothelial cel s. Attachment, proliferation and morphological changes of vascular endothelial cel s on the composite were observed by scanning electron microscope and MTT assay to evaluate its biocompatibility. PVA/l-CA three-dimensional scaffold with different contents of l-CA were constructed, and hemolysis experiment was conducted according to the biological evaluation standards of medical devices, and the porosity and pore size were observed using scanning electron microscope. RESULTS AND CONCLUSION:In vitro experimental results showed that the addition of l-CA could significantly increase the biological activity of PVA hydrogel, and promote the cel attachment and proliferation on the scaffold. The hemolysis rate of each experimental group was less than 5%(the accepted safety standard), suggesting that the composite materials were in accordance with the standard of medical devices for hemolysis experiment. These findings indicate that the composite scaffolds with 20%-30%l-CA possess the pore size suitable for cel growth and proliferation and the porosity beneficial for transportation of nutrients and metabolites, which can serve as an excel ent scaffold for tissue engineering.

Identification of novel common mutations among patients with non-syndromic hearing loss with high-throughput gene capture technology / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To identify novel common mutations among patients with non-syndromic hearing loss (NSHL).</p><p><b>METHODS</b>High-throughput gene capture technology was used to analyze 18 patients with NSHL in whom common mutations of deafness genes including GJB2, SLC26A4, GJB3, and mtDNA were excluded. Suspected mutation was verified with Sanger sequencing.</p><p><b>RESULTS</b>Next generation sequencing has identified 62 mutations in 29 genes associated with hearing loss, which included 54 missense mutations, 4 splicing mutations, 3 deletional mutations, and 1 nonsense mutation. Mutations occurring more than twice in the 18 patients were verified by Sanger sequencing. This has confirmed 15 mutations in 8 genes, including 3 missense mutations (p.C2184G, p.L2825P, p.H1888Y) which have not been reported previously. Meanwhile, p.L445W, p.D866N, and IVS919-2A>G were common causative mutations.</p><p><b>CONCLUSION</b>A number of common causative mutations, e.g., p.L445W, p.D866N, IVS919-2A>G, have been identified by high-throughput capture technology, which may facilitate the research and genetic diagnosis for hearing loss.</p>

Detection of common deafness-related genes among non-syndromic deafness patients from Shanxi province / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To explore the common causative genes and mutation sites for hereditary non-syndromic deafness in Shanxi.</p><p><b>METHODS</b>Peripheral blood samples were collected from regional schools for children with deafness. The samples were analyzed by matrix-assisted laser desorption ionization of flight mass spectrometry, and the results were verified by DNA sequencing.</p><p><b>RESULTS</b>For all samples, the 20 mutational sites of the 4 common causative genes were tested. As revealed, c.235delC of GJB2 gene has the highest mutational rate (13.67%). c.IVS7-2A>G of SLC26A (PDS) gene has a mutation rate of 17.67%, and c.1555A>G of mitochondrial 12S rRNA has a mutation rate of 2.00%. No mutations have been found with GJB3 gene. Sequencing analysis has suggested that the above results have a consistency rate of 99%.</p><p><b>CONCLUSION</b>Analysis of mutations of the 4 common deafness-related genes can facilitate early diagnosis and treatment for the disease. Matrix-assisted laser desorption ionization time of flight mass spectrometry is a reliable method for such a task.</p>