Fabrication of hydrophilic medical catheter with hydrogel grafting and the in vivo evaluation of its histo-compatibility / 生物医学工程学杂志

The biocompatible hydrogel was fabricated under suitable conditions with natural dextran and polyethylene glycol (PEG) as the reaction materials. The oligomer (Dex-AI) was firstly synthesized with dextran and allylisocyanate (AI). This Dex-AI was then reacted with poly (ethyleneglycoldiacrylate) (PEGDA) under the mass ratio of 4∶6 to get hydrogel (DP) with the maximum water absorption of 810%. This hydrogel was grafted onto the surface of medical catheter via diphenyl ketone treatment under ultraviolet (UV) initiator. The surface contact angle became lower from (97 ± 6.1)° to (25 ± 4.2)° after the catheter surface was grafted with hydrogel DP, which suggests that the catheter possesses super hydrophilicity with hydrogel grafting. The evaluation after they were implanted into ICR rats subcutaneously verified that this catheter had less serious inflammation and possessed better histocompatibility comparing with the untreated medical catheter. Therefore, it could be concluded that hydrogel grafting is a good technology for patients to reduce inflammation due to catheter implantation, esp. for the case of retention in body for a relative long time.

Hyaluronic acid production by Streptococcus iniae and its application in rabbit skin's regeneration / 生物工程学报

Hyaluronic acid (HA) is an important biomaterial as the extracellular matrix in human body. We produced HA by fermentation of Streptococcus iniae (Strep.). Production of HA by Strep. was evaluated and further improved by strain mutation by ultraviolet. One strain with higher HA yield and lower content of protein was obtained. Its HA yield increased from (82.3±3.3) mg/L to (120±10.6) mg/L, and protein decreased from (0.178±0.011) mg/L to (0.032±0.017) mg/L. The molecular weight (MW) of HA yield from Strep. is about 3.0×10⁵ Da. Using the method of freezing and thawing, HA aqueous solution was transferred into hydrogel. This HA hydrogel, casted on sterilized non-woven fabric, was applied to repair rabbit skin with full-thickness defect. The preliminary results of the animal tests displayed that HA hydrogel obviously reduced the inflammation around the wound and promoted the skin regeneration comparing with the control tests.

Effect of DJ-1 silencing by RNA interference on growth of xenografted human laryngeal squamous cell carcinoma Hep-2 cells in nude mice / 浙江大学学报·医学版

To investigate the effect of silencing DJ-1 on xenografted human laryngeal squamous cell carcinoma (LSCC) Hep-2 cells in nude mice.Xenograft model of human LSCC was established by subcutaneous transplantation of Hep-2 cells in 24 nude mice. The LSCC-bearing nude mice were randomly divided into 3 groups (=8 in each):DJ-1 siRNA low dose group and DJ-1 siRNA high dose group were injected in tumors with 20 μg of DJ-1 siRNA or 40 μg of DJ-1 siRNA in 50 μL, respectively; control group was injected with 5% glucose solution in 50 μL, twice a week for 3 weeks. The weight and size of tumors were measured before injection. The animals were sacrificed 48 h after the final treatment, and the tumors were harvested and weighed. The apoptosis and proliferation of tumor cells were determined; the expressions of Caspase-3 and Ki-67 in tumor specimens were detected with immunohistochemistry. The expression of DJ-1, PTEN, survivin mRNA and protein in tumor tissues were detected by RT-PCR and Western blotting, respectively.Tumor weight in low dose group[(0.66±0.15)g] and high dose group[(0.48±0.11)g] were significantly lower than that in control group[(0.83±0.16)g, all<0.05]. The inhibition rates of low dose group and high dose group were (20.48±0.18)% and (42.16±0.13)%, respectively. Immunohistochemistry showed that the expression of Caspase-3 was increased and Ki-67 was reduced in tumor specimens, compared with the control group (all<0.05). RT-PCR and Western blot results showed that in low dose group and high dose group the mRNA and protein expression of DJ-1 and survivin significantly decreased (all<0.05), while PTEN mRNA and protein content increased (all<0.05).High dose DJ-1 siRNA can inhibit the tumor growth in human LSCC xenograft nude mouse model, which indicates that down-regulating DJ-1 and survivin, and up-regulating PTEN expression may lead to blockage of PI3K-PKB/Akt signaling pathway and promoting tumor cell apoptosis.

Growth inhibitory effect of microRNA-519b-3p on larynx squamous Hep-2 cells / 中华耳鼻咽喉头颈外科杂志

<p><b>OBJECTIVE</b>To investigate the effects of microRNA-519b-3p (miR-519b-3p) on laryngeal carcinoma Hep-2 cell growth, and to analyze the underlying molecular mechanisms.</p><p><b>METHODS</b>The effects of miR-519b-3p on the growth and cell cycle of Hep-2 cells transfected with miR-519b-3p mimic were tested by MTT assay and flow cytometry, respectively. The mRNA and protein expressions of the related genes were tested by reverse transcription polymerase chain reaction (RT-PCR) and Western blot, respectively. The expressions of miR-519b-3p were tested by real-time RT-PCR in 48 pairs of laryngeal carcinoma and adjacent tissue samples.</p><p><b>RESULTS</b>The expression of miR-519b-3p in laryngeal carcinoma tissues was significant lower than that in adjacent non-cancerous tissues (S(ΔCt) = 2.989, t = 2.693, P < 0.01) . Increasing the level of miR-519b-3p inhibited significantly Hep-2 cell proliferation, arrested the cell cycle in the G2/M phase (10.29% ± 4.63%, t = 4.395, P < 0.05) , and decreased significantly the percentage of cells in the S phase (7.56% ± 2.05%, t = 3.555, P < 0.05) , with the increase in the expression of cyclin dependent kinase (CDK) 1 and the decrease in the expressions of CDK 2 and Cyclin A. RT-PCR and Western blot showed that miR-519b-3p down-regulated the protein but not mRNA expressions of HuR and cyclooxygenase-2(COX-2) genes.</p><p><b>CONCLUSIONS</b>The expression of MiR-519b-3p as carcinoma suppressor gene is low in laryngeal carcinoma. The cell cycle of Hep-2 cells was arrested in the G2/M phase by MiR-519b-3p.</p>

Compatibility of polyurethane membranes after surface modification with human hypopharyngeal fibroblasts / 中国组织工程研究

BACKGROUND:Polyurethane has good mechanical and physical characteristics and is extensively used in clinical and experimental studies, but its hydrophobicity and histocompatibility are not ideal, which limits its use in tissue engineering as a biomaterial scaffold to some extents. OBJECTIVE:To observe the hydrophilicity of polyurethane membrane grafted with silk fibroin and glutin and its compatibility with human hypopharyngeal cel s. METHODS:The changes in hydrophilicity of polyurethane membrane grafted with silk fibroin and glutin were detected by contact angle measurements. Human hypopharyngeal fibroblasts were cultured in vitro on polyurethane membrane, silk fibroin-polyurethane membrane, glutin-polyurethane membrane and tissue culture plate. Cel compatibility was compared using cytometry and cel morphology obsevation. RESULTS AND CONCLUSION:Hydrophilicity of silk fibroin-or glutin-polyurethane membranes significantly increased (Pglutin-polyurethane membrane (Pthan that on the polyurethane membrane, especial y on the silk fibroin-polyurethane membrane. These suggested that hydrophilicity and cel compatibility of silk fibroin-or glutin-polyurethane membrane were elevated.

The significance of anastomosing the recurrent laryngeal nerve in the thyroidectomy / 临床耳鼻咽喉头颈外科杂志

OBJECTIVE@#To study the significance of exposure of the recurrent laryngeal nerve (RLN ) in thyroid gland surgery.@*METHOD@#Three hundred and thirty-two thyroidectomy cases were studied from January 2008 to June 2011. All patients had general anesthesia, and RLN were exposed during operation. One hundred and thirty-one cases were operated with total lobectomies, 138 cases with subtotal thyroidectomy, 51 cases with total lobectomies and contralateral subtotal thyroidectomy, 12 cases with total thyroidectomy.@*RESULT@#Five hundred and thirty-three RLNs were exposed, 4 cases came with hoarseness postoperatively, All cases recovered within 3 months.@*CONCLUSION@#Exposure the recurrent laryngeal nerve in the thyroidectomy was available and could protect RLN.

Peripheral facial paralysis in temporal bone trauma and cholesteatoma otitis media / 临床耳鼻咽喉头颈外科杂志

OBJECTIVE@#To investigate into the surgical approaches and clinical curative effect of peripheral facial nerve paralysis in different causes and injury location.@*METHOD@#Thirty-two cases of peripheral facial paralysis were treated with selective facial nerve decompression via different surgical approaches. After 0.5 year to 2 years follow up, the recovered functions of facial nerve were judged by House and Brackmann grading system.@*RESULT@#In all patients, 17 cases of peripheral facial paralysis caused by trauma were underwent facial nerve decompression in two weeks, 11 cases reached degree I (84.6%) according to House-Brackmann (H-B) facial nerve function scores, 3 cases were treated in the third week, 2 cases reached degree II and other 1 cases reached degree III. One patient was treated after 8 weeks and facial nerve function scores only reached degree VI. Thirteen cases of otomastoiditis in middle ear were underwent facial nerve decompression in one week, postoperative House-Brackmann grade was I in 8 cases, II in 2, and III in 4.@*CONCLUSION@#Majority of patients with peripheral facial paralysis were treated with facial nerve decompression have better clinical curative effect by suitable operation and juncture due to trauma or cholesteatoma otitis media, but operation for traumatic peripheral facial paralysis should be undertaken in two weeks.