Effect of Functionalization of Texturized Polypropylene Surface by Silanization and HBII-RGD Attachment on Response of Primary Abdominal and Vaginal Fibroblasts.

Soft tissue defects, such as incisional hernia or pelvic organ prolapse, are prevalent pathologies characterized by a tissue microenvironment rich in fragile and dysfunctional fibroblasts. Precision medicine could improve their surgical repair, currently based on polymeric materials. Nonetheless, biomaterial-triggered interventions need first a better understanding of the cell-material interfaces that truly consider the patients' biology. Few tools are available to study the interactions between polymers and dysfunctional soft tissue cells in vitro. Here, we propose polypropylene (PP) as a matrix to create microscale surfaces w/wo functionalization with an HBII-RGD molecule, a fibronectin fragment modified to include an RGD sequence for promoting cell attachment and differentiation. Metal mold surfaces were roughened by shot blasting with aluminum oxide, and polypropylene plates were obtained by injection molding. HBII-RGD was covalently attached by silanization. As a proof of concept, primary abdominal and vaginal wall fasciae fibroblasts from control patients were grown on the new surfaces. Tissue-specific significant differences in cell morphology, early adhesion and cytoskeletal structure were observed. Roughness and biofunctionalization parameters exerted unique and combinatorial effects that need further investigation. We conclude that the proposed model is effective and provides a new framework to inform the design of smart materials for the treatment of clinically compromised tissues.

The impact of KRAS mutations on VEGF-A production and tumour vascular network.

BACKGROUND: The malignant potential of tumour cells may be influenced by the molecular nature of KRAS mutations being codon 13 mutations less aggressive than codon 12 ones. Their metabolic profile is also different, with an increased anaerobic glycolytic metabolism in cells harbouring codon 12 KRAS mutations compared with cells containing codon 13 mutations. We hypothesized that this distinct metabolic behaviour could be associated with different HIF-1α expression and a distinct angiogenic profile. METHODS: Codon13 KRAS mutation (ASP13) or codon12 KRAS mutation (CYS12) NIH3T3 transfectants were analyzed in vitro and in vivo. Expression of HIF-1α, and VEGF-A was studied at RNA and protein levels. Regulation of VEGF-A promoter activity was assessed by means of luciferase assays using different plasmid constructs. Vascular network was assessed in tumors growing after subcutaneous inoculation. Non parametric statistics were used for analysis of results. RESULTS: Our results show that in normoxic conditions ASP13 transfectants exhibited less HIF-1α protein levels and activity than CYS12. In contrast, codon 13 transfectants exhibited higher VEGF-A mRNA and protein levels and enhanced VEGF-A promoter activity. These differences were due to a differential activation of Sp1/AP2 transcription elements of the VEGF-A promoter associated with increased ERKs signalling in ASP13 transfectants. Subcutaneous CYS12 tumours expressed less VEGF-A and showed a higher microvessel density (MVD) than ASP13 tumours. In contrast, prominent vessels were only observed in the latter. CONCLUSION: Subtle changes in the molecular nature of KRAS oncogene activating mutations occurring in tumour cells have a major impact on the vascular strategy devised providing with new insights on the role of KRAS mutations on angiogenesis.

Preventive midline laparotomy closure with a new bioabsorbable mesh: an experimental study.

BACKGROUND: Incisional hernia formation is one of the most frequent complications of midline laparotomies requiring reoperation. The aim of this study was to evaluate the safety and efficacy of prophylactically placing a biodegradable mesh within the incision site at closure in a rat model. METHODS: A 4-cm full-thick midline laparotomy was made in Sprague-Dawley rats along the linea alba and closed by inserting a commercially available web of synthetic polymers (polyglycolic acid-trimethylene carbonate) that are slowly degraded by the body. Host tissue reaction was evaluated ex vivo and compared with that obtained in suture-only-treated rats. Specimens were harvested at 1, 3, and 6mo after surgery and divided for histologic and zymographic analyses and uniaxial material testing. A group of intact nonoperated animals were included to serve as a reference. RESULTS: The excised tissue explants revealed that the performance of the synthetic device was good and resulted in enhanced fibroproliferation, gelatinolytic activity, and angiogenesis within the repair site as compared with the suture-only procedure. Lastly, tensile strength augmented over the suture-only condition. CONCLUSIONS: The preventive introduction of an absorbable mesh stimulates new tissue ingrowth and performance relative to suture repair without prosthesis, probably contributing to eventually reinforce the tension line. These results have a clinical potential in abdominal wall closure, especially in patients with multiple risk factors such as those treated for aortic reconstructive surgery, without the short- and long-term complications related to permanent grafts. However, data are preliminary and should be confirmed with longer follow-ups.

ALCAM shedding at the invasive front of the tumor is a marker of myometrial infiltration and promotes invasion in endometrioid endometrial cancer.

Endometrial cancer (EC) is the sixth deadliest cancer in women. The depth of myometrial invasion is one of the most important prognostic factors, being directly associated with tumor recurrence and mortality. In this study, ALCAM, a previously described marker of EC recurrence, was studied by immunohistochemistry at the superficial and the invasive tumor areas from 116 EC patients with different degree of myometrial invasion and related to a set of relevant epithelial and mesenchymal markers. ALCAM expression presented a heterogeneous functionality depending on its localization, it correlated with epithelial markers (E-cadherin/ß-catenin) at the superficial area, and with mesenchymal markers at the invasive front (COX-2, SNAIL, ETV5, and MMP-9). At the invasive front, ALCAM-negativity was an independent marker of myometrial invasion. This negativity, together with an increase of soluble ALCAM in uterine aspirates from patients with an invasive EC, and its positive correlation with MMP-9 levels, suggested that ALCAM shedding by MMP-9 occurs at the invasive front. In vivo and in vitro models of invasive EC were generated by ETV5-overexpression. In those, we demonstrated that ALCAM shedding was related to a more invasive pattern and that full-ALCAM recovery reverted most of the ETV5-cells mesenchymal abilities, partially through a p-ERK dependent-manner.

Complex Abdominal Wall Hernia Repair in Contaminated Surgical Fields: Factors Affecting the Choice of Prosthesis.

To compare patients with complex abdominal wall hernias undergoing surgical repair using synthetic nonabsorbable or biologic meshes in contaminated fields. Retrospective review of 62 patients with complex abdominal wall hernia with surgical repair in an elective setting and in the context of a clean-contaminated or contaminated fields (January 2009-April 2015). Two groups according to the prosthesis (synthetic nonabsorbable, n = 48 or biologic, n = 14). Mean follow-up was 24.6 (15.8) months. Clean-contaminated wounds were significantly more frequent in the synthetic group. Contaminated wounds were significantly more frequent in the biologic group. Enterocutaneous fistula, recurrent hernia, and removal of chronic infected mesh were significantly more frequently in the biologic group. Differences in postoperative complications and surgical site infections were not found. Recurrence was higher in the biologic group (35.7% vs 8.3%, P = 0.03). In the elective repair of complex hernia, the level of contamination, a recurrent hernia, an enterocutaneous fistula or removal of chronic infected mesh were the factors affecting the choice of prosthesis. In the clean-contaminated setting, the use of a synthetic nonabsorbable mesh versus a biologic mesh did not increase the rate of postoperative infections. Recurrences are significantly higher with biologic meshes.