Regeneration of peritoneal mesothelial cells after placement of hyaluronate carboxymethyl-cellulose (Seprafilm®)

Composite Polycaprolactone/Gelatin Nanofiber Membrane Scaffolds for Mesothelial Cell Culture and Delivery in Mesothelium Repair

To repair damaged mesothelium tissue, which lines internal organs and cavities, a tissue engineering approach with mesothelial cells seeded to a functional nanostructured scaffold is a promising approach. Therefore, this study explored the uses of electrospun nanofiber membrane scaffolds (NMSs) as scaffolds for mesothelial cell culture and transplantation. We fabricated a composite NMS through electrospinning by blending polycaprolactone (PCL) with gelatin. The addition of gelatin enhanced the membrane's hydrophilicity while maintaining its mechanical strength and promoted cell attachment. The in vitro study demonstrated enhanced adhesion of mesothelial cells to the scaffold with improved morphology and increased phenotypic expression of key marker proteins calretinin and E-cadherin in PCL/gelatin compared to pure PCL NMSs. In vivo studies in rats revealed that only cell-seeded PCL/gelatin NMS constructs fostered mesothelial healing. Implantation of these constructs leads to the regeneration of new mesothelium tissue. The neo-mesothelium is similar to native mesothelium from hematoxylin and eosin (H&E) and immunohistochemical staining. Taken together, the PCL/gelatin NMSs can be a promising scaffold for mesothelial cell attachment, proliferation, and differentiation, and the cell/scaffold construct can be used in therapeutic applications to reconstruct a mesothelium layer.

A Review of Advanced Abdominal Wall Hernia Patch Materials

Tension-free abdominal wall hernia patch materials (AWHPMs) play an important role in the repair of abdominal wall defects (AWDs), which have a recurrence rate of <1%. Nevertheless, there are still significant challenges in the development of tailored, biomimetic, and extracellular matrix (ECM)-like AWHPMs that satisfy the clinical demands of abdominal wall repair (AWR) while effectively handling post-operative complications associated with abdominal hernias, such as intra-abdominal visceral adhesion and abnormal healing. This extensive review presents a comprehensive guide to the high-end fabrication and the precise selection of these advanced AWHPMs. The review begins by briefly introducing the structures, sources, and properties of AWHPMs, and critically evaluates the advantages and disadvantages of different types of AWHPMs for AWR applications. The review subsequently summarizes and elaborates upon state-of-the-art AWHPM fabrication methods and their key characteristics (e.g., mechanical, physicochemical, and biological properties in vitro/vivo). This review uses compelling examples to demonstrate that advanced AWHPMs with multiple functionalities (e.g., anti-deformation, anti-inflammation, anti-adhesion, pro-healing properties, etc.) can meet the fundamental clinical demands required to successfully repair AWDs. In particular, there have been several developments in the enhancement of biomimetic AWHPMs with multiple properties, and additional breakthroughs are expected in the near future.

Hyaluronic acid sheet transplantation attenuates infrapatellar fat pad fibrosis and pain in a rat arthritis model

Fibrosis of the infrapatellar fat pad (IFP) occurs after knee joint surgery or during knee osteoarthritis (KOA) and causes persistent pain and limited mobility. Previous studies demonstrated that treating IFP fibrosis alleviated pain in animal models. In this study, we examined the effects of hyaluronic acid (HA) sheet transplantation on IFP fibrosis and articular cartilage degeneration in a monoiodoacetic acid (MIA) rat arthritis model (95 male rats). Rats received bilateral intra-articular MIA injections (1.0 mg/30 μL) and underwent surgery 4 days later. HA sheets were transplanted on the right knee of each rat (HA group), with the left knee receiving sham surgery (sham group). Incapacitance tests were performed at multiple time points up to 28 days after MIA injection. Macroscopic, histological, and immunohistochemical analyzes were performed 14 and 28 days after injection. The concentrations of HA and interleukin-1β (IL-1β) in the synovial fluid were measured using ELISA. Transplantation of HA sheets could alleviate persistent pain 10-28 days after injection. The HA sheets inhibited articular cartilage degeneration at 14 days. Fibrosis and the invasion of calcitonin gene-related peptide-positive nerve fiber endings in the IFP were inhibited at both 14 and 28 days. Moreover, the HA sheets remained histologically until 10 days after transplantation. The concentration of HA reached its peak on Day 10 after transplantation; the concentration of IL-1β in the sham group was significantly higher than that in the HA group on Day 7. Therefore, HA sheets could be a promising option to treat IFP fibrosis occurring in KOA and after knee joint surgery.

Platelet-rich fibrin prevents postoperative intestinal adhesion

Platelet-rich fibrin (PRF) was prepared from the blood of BALB/C inbred mice to explore potential effects on postoperative intestinal adhesion. A murine model of intestinal adhesion characterized by abdominal wall defect/and cecum damage was established by scraping caecum serosa and cutting peritoneum and muscles in the abdominal wall. The wound was covered with PRF (group A), sodium hyaluronate (group B), or left alone (blank control; group C). All animals were monitored for 28 days. The incidence of adhesion was 35.0, 66.7, and 73.7% in groups A, B, and C, respectively. The incidence of adhesion in group A was significantly lower than that in group C (p < .05). Histopathologically, severity of fibrosis and the number of fibroblasts or inflammatory cells in group A were lower than those in groups B and C (p < .05), whereas the number of mesothelial cells was higher (p = .001). Furthermore, the severity of fibrosis and number of fibroblasts or inflammatory cells were lower in low grade than those in high grade of adhesion (p < .05), whereas the number of mesothelial cells was higher (p < .05). Collectively, PRF applied to abdominal surgery may reduce the incidence of intestinal adhesion by promoting proliferation of mesothelial cells whereas inhibiting proliferation of fibroblasts and infiltration of inflammatory cells.

Lactobacillus reuteri protects mice against Salmonella typhimurium challenge by activating macrophages to produce nitric oxide

Lactobacillus reuteri, a typical intestinal symbiotic bacterium, plays an important role in maintaining intestinal flora stability and host health. However, the effect of Lactobacillus reuteri on peritoneal macrophages has not been thoroughly studied. Our study indicated that Lactobacillus reuteri could activate macrophages and that macrophages treated with Lactobacillus reuteri have an enhanced ability to phagocytose and to kill intracellular Salmonella typhimurium. Lactobacillus reuteri may reduce the inflammatory response caused by Salmonella typhimurium by regulating NO, thus effectively protecting mice against Salmonella typhimurium invasion and dissemination to the liver and spleen. Taken together, these data demonstrated the protective effect of Lactobacillus reuteri on macrophages and mice challenged with Salmonella typhimurium through in vitro and in vivo experiments.

Comparison of clinical outcomes of laparoscopic versus open surgery for recurrent hepatocellular carcinoma: a meta-analysis

BACKGROUND

The purpose of this study is to compare the clinical outcomes of laparoscopic liver resection versus open liver resection for recurrent hepatocellular carcinoma (RHCC).

METHODS

Published studies which investigated laparoscopic versus open liver resection for RHCC were identified, and meta-analysis was used for statistical analysis.

RESULTS

Six studies were analyzed by meta-analysis method, and cumulative 335 cases were included in this study. Laparoscopic liver resection was performed in 145 cases, and open liver resection was performed in 190 cases. Meta-analysis showed that there was no difference in operative time and 90-day mortality between the laparoscopic group and the open group (p = 0.06 and p = 0.06 respectively); Nevertheless, compared with the open group, the laparoscopic group resulted in significantly lower rate of in-hospital complication (p < 0.0001), much less blood loss (p < 0.0001) and shorter postoperative hospital stay (p = 0.002).

CONCLUSION

Laparoscopic liver resection for RHCC offers a benefit of lower in-hospital complication rate, less blood loss, shorter postoperative hospital stay, while similar operative time and 90-day mortality as the open liver resection. Laparoscopic liver resection is feasible with satisfactory postoperative outcomes and can be a safe alternative treatment strategy to open procedure for RHCC.

Short-term surgical outcomes of minimally invasive repeat hepatectomy for recurrent liver cancer

BACKGROUND

Repeat liver resection is an effective treatment, with long-term surgical outcomes for recurrent hepatocellular carcinoma and colorectal liver metastasis. However, the efficacy of a minimally invasive surgical approach for recurrent liver cancer is not yet confirmed. The purpose of this study is to examine the efficacy of minimally invasive repeat liver resection (MISRLR) compared with open repeat liver resection (ORLR) for primary and metastatic liver cancer. Here, we retrospectively analyzed the clinicopathological features and short-term surgical outcomes of patients undergoing MISRLR and ORLR.

METHODS

From 2005 to 2016, 97 patients with liver cancer underwent repeat hepatectomy. Of these patients, 68 patients receiving macroscopically curative resection and only hepatectomy, without other additional operations, were selected. Twenty patients underwent MISRLR and 48 patients underwent ORLR. We compared the clinicopathological and surgical parameters in the MISRLR group with those in the ORLR group.

RESULTS

There were no statistically significant differences in patients' gender, age, viral infection status, Child-Pugh classification, tumor size, tumor number, tumor location, or the presence of liver cirrhosis in the two groups. The operative times were similar, but blood loss was significantly lower in MISRLR group (159 vs. 502 ml, P = 0.0035). The length of the postoperative hospital stay was significantly shorter in the MISRLR group (14.2 vs. 19.2 days, P = 0.0275). Postoperative complications were observed only in the ORLR group, with a complication rate of 19%.

CONCLUSIONS

We demonstrate that MISRLR for primary and metastatic liver cancer reduces blood loss and postoperative complications compared with ORLR. MISRLR might be a feasible and effective procedure for the selected patients.

Neoadjuvant CapeOx therapy followed by sphincter-preserving surgery for lower rectal cancer

PURPOSE

This retrospective study investigates the safety of neoadjuvant chemotherapy with oxaliplatin capecitabine (CapeOx), followed by laparoscopic surgery, for lower rectal cancer, and its efficacy in preserving the sphincter.

METHODS

Ten patients with diagnosed lower rectal cancer received three or four cycles of neoadjuvant CapeOx chemotherapy, prior to undergoing low anterior resection or intersphincteric resection, with total mesorectal excision. The primary outcomes were R0 resection and the rate of sphincter preservation.

RESULTS

Nine patients completed CapeOx as scheduled and a partial response was achieved in four; thus, the overall response rate was 40% (n = 4/10). After surgical intervention, 80% of tumors displayed downstaging. Postoperative anastomosis leakage developed in one patient. The distance from the anal verge to the tumor increased by 60% (median 1.5 cm) after CapeOx treatment. The anal sphincter was preserved in all patients and all pathological distal and radial margins were negative (R0 resections). A pathological complete response was achieved in one patient.

CONCLUSIONS

Neoadjuvant CapeOx chemotherapy is a promising approach, because it extended the distance from the anus to the tumor. Subsequent laparoscopic intervention for advanced lower rectal cancer could allow for safe preservation of the sphincter.