Controlled siRNA Release of Nanopolyplex for Effective Targeted Anticancer Therapy in Animal Model.

Introduction: Spatiotemporally controlled release of siRNA for anti-tumor therapy poses significant challenges. Near-infrared (NIR) light, known for its exceptional tissue penetration and minimal tissue invasiveness, holds promise as a viable exogenous stimulus for inducing controlled siRNA release in vivo. However, the majority of light-responsive chemical bonds exhibit absorption wavelengths in the ultraviolet (UV) or short-wavelength visible light range. Methods: To achieve NIR-controlled siRNA release, the study synthesized a UV-sensitive triblock copolymer cRGD-poly(ethylene glycol)-b-poly(aspartic acid ester-5-(2'-(dimethylamino)ethoxy)-2-nitrobenzyl alcohol)-b-polyphenylalanine, abbreviated as cRGD-PEG-PAsp(EDONB)-PPHE. This copolymer is composed of a cRGD-capped PEG block (cRGD-PEG), a poly(aspartate) block modified with cationic moieties through UV-cleavable 2-nitrobenzyl ester bonds [PAsp(EDONB)], and a hydrophobic polyphenylalanine block (PPHE). The cationic amphiphilic polymer cRGD-PEG-PAsp(EDONB)-PPHE can assemble with hydrophobic upconversion nanoparticles (UCNPs) to form a cationic micelle designated as T-UCNP, which subsequently complexes with siRNA to create the final nanopolyplex T-si/UCNP. siRNA-PLK1 was employed to prepare T-PLK1/UCNP nanopolyplex for anti-tumor therapy. Results: T-PLK1/UCNP not only exhibited outstanding tumor cell targeting through cRGD modification but also achieved 980 nm NIR-controlled PLK1 gene silencing. This was achieved by utilizing the encapsulated UCNPs to convert NIR into UV light, facilitating the cleavage of 2-nitrobenzyl ester bonds. As a result, there was a significant suppression of tumor growth. Conclusion: The UCNPs-encapsulated nanopolyplex T-si/UCNP, capable of co-delivering siRNA and UCNPs, enables precise NIR-controlled release of siRNA at the tumor site for cancer RNAi therapy. This nanopolyplex can enhance the controllability and safety of RNAi therapy for tumors, and it also holds the potential to serve as a platform for achieving controlled release and activation of other drugs, such as mRNA and DNA.

A rare gastric metastasis secondary to residual cystic duct carcinoma: case report and literature review.

An unusual gastric metastasis from residual cystic duct carcinoma was reported, which was easily mistaken as primary gastric carcinoma before the surgery. A 50-year-old Chinese man presented with right upper abdominal discomfort. Based on the biopsy and computed tomography results, an advanced gastric antrum adenocarcinoma was primarily diagnosed. Intraoperatively, there were other findings: residual cystic duct with chronic hyperplasia, a suspected purulent cavity filled with grayish-brown cloudy liquid at the distal end of the cystic duct and the gallbladder socket. The patient underwent radical operation. Histopathological findings finally suggested that adenocarcinoma of the residual cystic duct infiltrated into the whole layer of the gastric wall. Postoperative adjuvant chemotherapy and immunotherapy were administered. The patient has achieved 20-month recurrence-free survival. The comprehensive treatment including radical surgery, adjuvant chemotherapy and immunotherapy may improve the prognosis of such patients.

Probiotics and dietary intervention modulate the colonic mucosa-associated microbiota in high-fat diet populations.

BACKGROUND/AIMS: Alterations in the gut microbiota due to a high-fat diet and diet-induced illness have been found in both mouse models and humans. Observational studies suggest that probiotic administration and diet shifts may treat diet-related diseases. However, the effect of these interventions on the colonic mucosa has not yet been elucidated. This study investigated the efficacy of probiotic supplementation and dietary intervention as prophylactic tools under high-fat diet conditions. MATERIALS AND METHODS: A total of 36 volunteers that normally consumed a high-fat diet were enrolled and treated with either a control diet, a low-fat dietary intervention, Bifidobacterium triple viable capsule therapy, or a combination of a low-fat diet and Bifidobacterium triple viable capsule therapy. Pyrosequencing of the V3 and V4 regions of the 16S rRNA genes was conducted to determine the extent to which probiotics and dietary intervention altered the mucosal microbiota. RESULTS: This study demonstrated that interventional treatment with probiotics and a low-fat diet increased the diversity of the mucosal microbes, dietary intervention alone produced the most significant effect, whereas the combined intervention exhibited no synergetic improvement. Pyrosequencing demonstrated that probiotics and dietary intervention significantly elevated the abundance of some bacterial taxa assigned to the phylum Firmicutes and the beneficial genera Prevotella, Gemmiger, Coprococcus, and Faecalibacterium and reduced some harmful bacterial taxa assigned to the phylum Proteobacteria and genus Streptophyta. CONCLUSION: The results of this study suggested that the addition of probiotics and dietary intervention could improve the composition of the colonic mucosal microbiota in high-fat diet populations.

Supplementation of triple viable probiotics combined with dietary intervention is associated with gut microbial improvement in humans on a high-fat diet.

Numerous animal studies have demonstrated that oral probiotics may have a beneficial role in preventing obesity, inflammatory bowel disease and even colorectal cancer, which are all associated with a high-fat diet (HFD). However, the underlying beneficial effects of combined probiotic and dietary intervention on the gut microbiota of 'non-patient' individuals previously on an HFD have yet to be fully elucidated. In the present study, fecal samples were obtained from 36 volunteers on a high-fat diet and after dietary intervention for 4 months, and 16S rDNA sequencing was applied to identify how probiotics and dietary intervention had altered the composition of the microbiota. The results demonstrated that probiotics treatment and dietary intervention in combination raised the diversity of lumen microbes compared with their individual applications. A markedly separated distribution (ß-diversity) was observed, confirming the difference in gut microbiota composition among the treatment groups. Bacterial taxonomic analysis demonstrated that the relative abundance of 30 species was altered among the groups following dietary intervention and/or probiotic supplementation. The majority of the species that exhibited a population increase belonged to two butyrate-producing families, Ruminococcaceae and Lachnospiraceae, whereas the species with reduced populations mainly belonged to the Bacteroidaceae family. Collectively, these results suggest that combined probiotic and dietary intervention is able to improve the gut microbiota composition of human subjects on an HFD.

Association analysis of dietary habits with gut microbiota of a native Chinese community.

Environmental exposure, including a high-fat diet (HFD), contributes to the high prevalence of colorectal cancer by changing the composition of the intestinal microbiota. However, data examining the interaction between dietary habits and intestinal microbiota of the Chinese population is sparse. We assessed dietary habits using a food frequency questionnaire (FFQ) in native Chinese community volunteers. Based on the dietary fat content determined using the FFQ, the volunteers were divided into HFD group (≥40% of dietary calories came from fat) or low-fat diet (LFD) group (<40%). Fecal and colonic mucosal microbiota composition was determined using 16S rDNA based methods. In stool matter of HFD group, Prevotella and Abiotrophia showed significantly higher abundance, whereas unclassified genus of S24-7 (family level) of Bacteroidetes, Gemmiger, Akkermansia and Rothia were less abundant. On colonic mucosal tissue testing, unclassified genus of S24-7 showed significantly higher abundance while Bacteroides, Coprobacter, Abiotrophia, and Asteroleplasma were less abundant in HFD group. A high fat and low fiber diet in a native Chinese community may partially contribute to changes of intestinal microbiota composition that may potentially favor the onset and progression of gastrointestinal disorders including inflammatory, hyperplastic and neoplastic diseases.

The study on the efficacy of fibrin glue in preventing post-traumatic focal pancreatitis (PTFP) after radical gastrectomy.

OBJECTIVE: This study was intended to evaluate the efficacy of fibrin glue (FG) in preventing post-traumatic focal pancreatitis (PTFP) after radical gastrectomy by examining the drainage fluids over 7 days post-op. METHODS: Ninety-five patients who underwent D2 radical gastrectomy for gastric cancer were randomly assigned to a fibrin glue group (n = 48) receiving fibrin glue on the raw surface of the pancreas during surgery and a control group (n = 47), which did not receive fibrin glue. RESULTS: We found no significant difference in operation time and intraoperative blood loss between groups (p > 0.05); no deaths occurred during surgery. The volume of ascitic fluid containing blood cells in the fibrin glue group was significantly lower than that in the control group (p < 0.001) at all times observed. Amylase levels in the drained fluids were highest at 24 h postoperatively in both groups, suggesting pancreatitis, but gradually decreased to normal levels within 7 days. The amylase in the drains in the control group was significantly higher than that in the FG group (p < 0.001) at all times observed, but it returned to normal 72 h postoperatively in the FG group. One death by hemorrhagic shock associated with PTFP was recorded in the control group. CONCLUSION: Fibrin glue is safe and effective in preventing PTFP following gastric surgery and shortens the clinical course of the disease.

[Application of modified quadruple stapling technique in radical proximal gastrectomy for gastric carcinoma].

OBJECTIVE: To investigate the feasibility and safety of modified quadruple stapling technique in radical proximal gastrectomy for gastric carcinoma. METHODS: Medical records of 55 consecutive patients who underwent radical proximal gastrectomy for gastric cancer were analyzed retrospectively. Twenty-eight patients (modified group) undergoing modified quadruple stapling technique were compared to 27 patients (traditional group) who underwent traditional approach during the same period. RESULTS: There was no perioperative mortality. All the patients had negative pathological resection margin. The mean operative time in the modified group was significantly shorter than that in the traditional group [(158±31) min vs. (195±42) min, P<0.05]. There were no immediate complications such as stricture, bleeding or leakage at the anastomosis, gastroparesis, and wound infection. Postoperative recovery did not differ between the two groups (P>0.05). During the follow-up (range: 3 months-2 years), 2 (7.1%) patients in the modified group and 2 (7.4%) in the traditional group developed reflux esophagitis (P>0.05) and anastomotic inflammation occurred in 2 cases (7.1%) for the modified group and 8 (29.6%) for the traditional group (P<0.05). CONCLUSION: Modified quadruple stapling technique is a feasible and safe method in radical proximal gastrectomy.

Neuronal progenitor cells seeded in fibrin gel differentiate into ChAT-positive neuron.

Previous studies indicate that neural progenitor cells seeded in fibrin can differentiate into the glia cells and neurons. However, whether fibrin gel can induce differentiation of neural progenitor cells of spinal cord into motoneurons remains to be elucidated. In this study, we prepared a fibrin-based hybrid gel incorporated with laminin and fibronectin using rat fresh plasma as a crosslinking agent. The physical properties of this hybrid gel were examined with electron microscope, as well as its degradation and vascularization after subcutaneous transplantation with histological methods. Immunofluorescence stainings were used to study the proliferation and differentiation of the neural progenitor cells seeded in this 3D hybrid gel. The results indicate that such a hybrid gel possesses the unique physical characteristics, and the ability to promote both the proliferation and differentiation of the neural progenitor cells into neuron, including ChAT-positive motoneuron. Thus, it is suggested that this hybrid gel might be suitable for a mimetic tissue transplant for central nerve system injury, such as injured spinal cord repair.

A novel biosynthetic hybrid scaffold seeded with olfactory ensheathing cells for treatment of spinal cord injuries.

BACKGROUND: Implantation of tissue-engineered scaffolds is one of the most promising therapeutic strategies for inducing nerve regenerations following spinal cord injuries. In this paper, we report a novel bioengineered hybrid scaffold comprised of three major extracellular matrix (ECM) proteins. METHODS: ECM-scaffolds (ECM-S) were prepared by gelling fibrinogen, fibronectin and laminin using fresh rat plasma. Olfactory ensheathing cells (OECs) were isolated from fresh rat olfactory mucosa, purified under differential adhesion, and assessed by immunofluorescent staining. OECs were seeded onto ECM-S and cultured. The effects of the scaffolds on the seeded cells were detected using the immunofluorescent staining, Western blotting, scanning electron microscopy and transmission electron microscopy. RESULTS: Tissue-engineered ECM-S could be easily molded into mat-like or cylindrical shapes and gelled by addition of fresh plasma. Observations by electron microscopy show that the ECM-S forms a stable three-dimensional porous network. Studies on the effects of the ECM-S on the biological behaviors of OECs in vitro indicate that the scaffold can promote OEC adhesion, proliferation and process extensions. Additionally, OECs seeded on the scaffold maintained the expression of nerve growth factor, matrix metalloproteinase-3 and matrix metalloproteinase-9. CONCLUSION: We developed a biosynthetic hybrid gel which could be used as a scaffold for OEC transplantation; this gel can promote nerve regeneration following spinal cord injuries.