Integrating Nanosensors into Macroporous Hydrogels for Implantation.

Macroporous hydrogels are an attractive platform for implantable sensors because the network of interconnected macropores facilitates tissue integration. Embedded sensing elements, in our case, plasmonic gold nanoparticles, can transduce the presence, absence, and concentration of biochemical markers to the outside. We present here how to integrate such nanosensors into a macroporous hydrogel while preserving the nanosensor functionality in order to produce implantable sensors. We demonstrate that out of four different polymers, the poly(2-hydroxyethyl methacrylate-poly(ethylene glycole)diacrylate copolymer (pHEMA-PEGDA) results in a working sensor. Our approach of incorporating nanosized sensor elements into a hydrogel matrix generally identifies suitable polymers for implantable sensor systems.

Implantable Sensors Based on Gold Nanoparticles for Continuous Long-Term Concentration Monitoring in the Body.

Implantable sensors continuously transmit information on vital values or biomarker concentrations in bodily fluids, enabling physicians to survey disease progression and monitor therapeutic success. However, currently available technologies still face difficulties with long-term operation and transferability to different analytes. We show the potential of a generalizable platform based on gold nanoparticles embedded in a hydrogel for long-term implanted biosensing. Using optical imaging and an intelligent sensor/reference-design, we assess the tissue concentration of kanamycin in anesthetized rats by interrogating our implanted sensor noninvasively through the skin. Combining a tissue-integrating matrix, robust aptamer receptors, and photostable gold nanoparticles, our technology has strong potential to extend the lifetime of implanted sensors. Because of the easy adaptability of gold nanoparticles toward different analytes, our concept will find versatile applications in personalized medicine or pharmaceutical development.

Effect of Acellular Amniotic Membrane Matrix Patch on Healing of Cut Surface After Sleeve Gastrectomy in Rats.

Background: The aim of this study was to evaluate the effect of acellular amniotic membrane matrix patch on healing cut surface after sleeve gastrectomy in rats. Methods: Thirty male Wistar albino rats were divided into three groups: control (n = 10), Experiment-1 (n = 10), and Experiment-2 (n = 10) groups. Control group rats underwent only sleeve gastrectomy with primary gastrorrhaphy. Experiment-1 group rats underwent sleeve gastrectomy, primary gastrorrhaphy and covered with acellular amniotic membrane matrix patch. Experiment-2 group rats underwent sleeve gastrectomy, incomplete primary gastrorrhaphy and covered with acellular amniotic membrane matrix patch. All rats were sacrificed on the fifth postoperative day. Macroscopic findings and histopathologic alterations were evaluated and compared. Results: There was a statistically significant difference between levels of PMNs, granulation formation and vascularization, distributions of edema, type of mucosal epithelium, and fibroblastic proliferation according to groups (p < 0.05). The PMNs level in the Experiment-1 group was significantly lower than the control group (p < 0.05). In experiment groups, the level of granulation tissue, vascularization and fibroblastic proliferation was significantly higher than the control group (p < 0.05). The levels of edema and type of mucosal epithelium of the experiment groups were significantly lower than the control group (p < 0.05). Conclusion: Covering sleeve gastrectomy cut surface area with acellular amniotic membrane matrix results better healing. Moreover, acellular amniotic membrane matrix provides safe healing even in incomplete sutured area.

Effect of local bleomycin sulfate application on seroma formation in a rat mastectomy and axillary lymph node dissection model.

Seroma formation is one of the most common complications following breast cancer surgery. It may lead to delay of adjuvant therapies and increasement of therapy costs. Bleomycin sulfate is a sclerosing antibiotic with antineoplastic efficacy. It is locally used in the treatment of pleural effusion. The present study aimed to investigate seroma-reducing effect of local bleomycin application after mastectomy. Sixteen female Wistar Albino rats were used in this study. The rats were divided into two equal groups. Under general anesthesia all rats underwent unilateral mastectomy as definition by Harada. Serum physiologic was applied to animals in Group 1 (control group) and bleomycin to Group 2. Mastectomized localization was explored on the 10th day postoperatively. Seroma and tissue samples were obtained from axilla and thoracic wall for histopathological examination. The amount of seroma was significantly lower in the bleomycin group as compared to the control group (P=0.002). Fibrosis, PNL infiltration and the number of fibroblasts were significantly higher in the bleomycin group. No difference was identified between the groups in terms of angiogenesis, edema, congestion, and monocyte, lymphocyte and macrophage infiltration. Local bleomycin sulfate application might be a therapeutic option in patients with seroma formation, as well as in the patients with malignant pleural effusion. Nonetheless, further studies that compare the efficacy and adverse effects (benefit-to-harm ratio) of bleomycin sulfate are needed.

A prospective comparative study to assess the contribution of radioisotope tracer method to dye-only method in the detection of sentinel lymph node in breast cancer.

BACKGROUND: Metastasis in the axillary lymph nodes is the most important known prognostic factor for breast cancer. We aimed to investigate the contribution of the radioisotope tracer method to the dye-only method by performing sentinel lymph node biopsy on the same patient group during a single surgical session. METHODS: Forty-two patients who underwent operations in our clinic from February 2010 to October 2011 and with masses of <5 cm and clinically and radiologicallly negative axilla (T1-2 N0) were prospectively included in this study. After paraffin examination results were obtained, the numbers and metastatic states of the lymph nodes that were unidentifiable during surgery (although they were stained) but were detected by a gamma probe, lymph nodes that were only stained, lymph nodes that were only radioactive (hot), and lymph nodes that were both stained and radioactive (stained-hot) were determined in all patients. In patients who underwent axillary lymph node dissection, the total numbers of lymph nodes removed and their metastatic states were determined separately. RESULTS: At least one blue-stained sentinel lymph node was identified in all patients during the blue-stained lymph node detection stage. The average number of sentinel nodes removed at this stage was 2.1 ± 1.1. In the second surgical stage (the stage in which nodes with axillary counts were investigated with the gamma probe) in these 41 patients, at least one additional hot node was removed, or at least one of the nodes that was removed because it was blue was also hot. In addition to the lymph nodes removed in the dye stage, 34 hot lymph nodes were excised from 21 patients. Overall, the average number of hot lymph nodes removed was 2.9 ± 1.5. In all patients, subsequent frozen sections and histopathological examinations were 100% concordant with the sentinel lymph nodes that were removed; the stained sentinel lymph nodes that were removed first did not affect the decision to perform axillary dissection. CONCLUSION: The results of our study indicate that performing sentinel lymph node biopsy with dye only is sufficient and as effective as the combined method.

Effects of local phenytoin on seroma formation after mastectomy and axillary lymph node dissection: an experimental study on mice.

BACKGROUND: Seroma formation is the most common complication after breast cancer surgery. It is an important complication since it prolongs therapy duration, increases cost, and negatively affects patient psychology. Currently, there is no widely accepted method that prevents seroma formation. We tried to investigate impact of local phenytoin application on seroma formation following an experimental mastectomy model created in rats. METHODS: Two groups including eight rats in each were randomized. Saline injection was applied in the first group, whereas 1% phenytoin was locally used in the second group. Ten days after the surgery, seroma formation and wound-healing processes were evaluated using histopathological and biochemical examinations. RESULTS: Phenytoin significantly decreased seroma formation. Fibrosis was significantly increased and angiogenesis was significantly reduced in the phenytoin group (P < 0.05). Increased levels of macrophage and lymphocyte infiltration was detected in the control group (P < 0.05). No difference was detected between the groups in terms of necrosis, edema, congestion, and PNL (Polymorphonuclear leucocyte) and fibroblast infiltration. CONCLUSIONS: Seroma formation-reducing effect of phenytoin might have occurred over its anti-inflammatory, anti-angiogenetic, and fibrosis augmenting effects.

Intra-abdominal use of phosphodiesterase type 4 inhibitor in postoperative adhesion prevention: an experimental study on mice.

OBJECTIVE: The study was designed to assess the value of intraperitoneal use of rolipram for adhesion prevention and to compare the results with placebo and a sodium hyaluronate/carboxymethylcellulose absorbable barrier (Seprafilm), in a murine cecal abrasion model. DESIGNS: Twenty-four Balb/c mice were subjects of this study. Intra-abdominal adhesions were created with a multiple-abrasion model consisting of meticulous abrasion of the cecum and small-bowel segments with strokes of a dental toothbrush. Animals in groups R (n = 8) received 1 mL of rolipram intraperitoneally. Seprafilm was placed over the viscera under the incision in group S animals (n = 8). Group C animals (n = 8) were reserved as control and received nothing. Animals were killed on day 22. MAIN OUTCOME MEASURES: The adhesions were evaluated with 2 different observational scoring systems, the Majuzi System and the Linsky Scale. After completion of observational evaluation, the cecum and small bowel of the animals were excised and sent to the pathology laboratory for histopathologic examination. The extent of inflammatory response, the extent of the fibrotic reaction, the extent of the necrosis and abscess formation, and the extent of foreign body reaction were histologically evaluated. RESULTS: The mean Majuzi System scores of groups R and S were similar to each other and significantly less than control group. Also, all scores of the Linsky Scale in group R were similar to those in group S, and significantly less than those in the control group. Histologically, the mean score of inflammatory response in group R was less than both those in group C and group S. The mean score of fibrotic reaction in group R was significantly less than those in the control group. CONCLUSION: These results indicate that rolipram may be an effective material in prevention of postoperative intra-abdominal adhesions, but it is obvious that further studies are needed to validate the results of this limited initial study.

Acute mechanical intestinal obstructions.

BACKGROUND: In this study, we evaluated our treatment modality and timing of surgery in acute mechanical intestinal obstruction (AMIO) patients who were admitted to the emergency room. METHODS: Only patients with the diagnosis of AMIO were included in this study. Surgery was performed in patients with hemodynamic instability despite fluid resuscitation and peritoneal signs upon physical examination. Patients were divided into two groups. Adhesion cases were assigned to Group 1, while non-adhesion cases were assigned to Group 2. The decision to provide surgical or medical therapy was assessed 24 hours (h) after admission. RESULTS: Twenty-two patients in Group 1 and 53 patients in Group 2 underwent surgical procedures. The difference between the groups was statistically different (p < 0.05). The mean monitoring time after admission to the hospital was 128.3 +/- 24.85 h and 43.1 +/- 15.51 h in Groups 1 and 2, respectively (p = 0.0001). In Group 2, 76.6% of the patients who were monitored for over 24 hours required surgery. In contrast, this rate was only 36% in Group 1 (p < 0.05). CONCLUSION: Our clinical experience shows that medical therapy and monitoring over 24 hours is not a good substitute for surgical treatment of AMIO when the obstruction is not due to an adhesion.

The role of simvastatin on postoperative peritoneal adhesion formation in an animal model.

AIM: The aim of this study is to show the effect of simvastatin on intra-abdominal adhesion formation. METHOD: Adhesion formation was achieved by scratching the cecum and anterior abdominal wall following median laparotomy. Three different groups of 10 rats each were formed. In group I, 0.57 mg/kg/day simvastatin was injected intraperitoneally right after the operation and for 5 days thereafter. In group II, an equal dose of simvastatin to that used in group I was given via gavage. A physiological saline solution was given to group III for the same period of time. On the 6th and 14th day, blood samples were taken and peritoneal lavage was performed to measure the tissue-type plasminogen activator (t-PA) activity. Adhesions were graded via re-laparotomies on the 14th day after the first operation. RESULTS: The adhesion scores were 1.40 +/- 0.22, 1.50 +/- 0.26, and 2.90 +/- 0.34 in groups I, II, and III, respectively (p = 0.007), and the score was higher in group III than in the other groups (p = 0.005, p = 0.011). CONCLUSION: Intraperitoneal simvastatin application decreases adhesion formation by increasing the t-PA level in abdominal surgery.

Sarcoidosis presenting as cold thyroid nodules: report of two cases.

Sarcoidosis is a systemic disease characterized by noncaseating granulomas. Thyroid involvement is rare in sarcoidosis. In this paper, two sarcoidosis patients who demonstrated cold thyroid nodules are presented. A 42-year-old woman presented with multinodular goiter and was diagnosed as having sarcoidosis when noncaseating granulomas were observed during the pathological examination of the thyroidectomy specimen. Enlarged mediastinal lymph nodes were observed in the routine preoperative chest X-ray in another 53-year-old woman, while she was being prepared to undergo a thyroidectomy. The pathological examination of the thyroid specimens showed noncaseating granulomas in both patients, and the diagnosis was confirmed by either hepatic biopsy or chest X-ray findings. In conclusion, thyroid involvement should be suspected in sarcoidosis patients who present with cold nodules in the thyroid. Furthermore, if noncaseating granulomas are observed in thyroid specimens after a thyroidectomy in an otherwise healthy person, the patient should be evaluated further for sarcoidosis.

Spontaneous and traumatic intra-peritoneal perforations of hepatic hydatid cysts: a case series.

Little is known about the presentation, management, outcome, and recurrence of hydatid cyst perforations. We reviewed the charts of all patients admitted to our emergency service for 7 years to identify patients who were surgically treated for intra-peritoneal hydatid cyst perforations. Twelve hydatid cysts were identified in 7 patients (5 males; median age 22 yr; range 8-67). The perforations occurred spontaneously in 5 patients, and were the result of mild trauma in 2 patients. Diagnostic tools included ultrasound (US, n = 4), computed tomography (CT, n = 3), and diagnostic peritoneal lavage (DPL, n = 1). The cysts were treated with radical (n = 3) or conservative (n = 9) operative techniques. Intra-cavitary and intra-abdominal spaces were washed in 6 and 5 patients, respectively. The median follow-up time was 41 months (range 3-58). Indirect hemagglutination test was positive in 3 patients, but CT confirmed cyst recurrence in only 2 of these patients. Both had had large cysts and had undergone conservative therapy (endocystectomy and external drainage). An intra-abdominal recurrence was observed in a patient whose abdomen had not been washed during surgery. In conclusion, patients with hydatid cyst perforations in our study generally presented with severe abdominal findings. US, CT, and DPL may be helpful for the diagnosis. Recurrence may be related to operative technique, location of the cyst, and abdominal wash during the surgery.