Hydrogel foam dressings with angiogenic and immunomodulatory factors from mesenchymal stem cells.

Stem cell therapy and skin substitutes address the stalled healing of chronic wounds in order to promote wound closure; however, the high cost and regulatory hurdles of these treatments limit patient access. A low-cost method to induce bioactive healing has the potential to substantially improve patient care and prevent wound-induced limb loss. A previous study reported that bioactive factors derived from apoptotic-like mesenchymal stem cells (MSCs) demonstrated anti-inflammatory and proangiogenic effects and improved ischemic muscle regeneration. In this work, these MSC-derived bioactive factors were loaded into a hydrogel foam to harness immunomodulatory and angiogenic properties from MSC components to facilitate chronic wound healing without the high cost and translational challenges of cell therapies. After incorporation of bioactive factors, the hydrogel foam retained high absorbency, moisture retention, and target water vapor transmission rate. High loading efficiency was confirmed and release studies indicated that over 90% of loaded factors were released within 24 h. Ethylene oxide sterilization and 4-week storage did not affect the bioactive factor release profile or physical properties of the hydrogel foam dressing. Bioactivity retention of the released factors was also confirmed for as-sterilized, 4°C-stored, and -20°C-stored bioactive hydrogel foams as determined by relevant gene expression levels in treated pro-inflammatory (M1) macrophages. These results support the use of the bioactive dressings as an off-the-shelf product. Overall, this work reports a new method to achieve a first-line wound dressing with the potential to reduce persistent inflammation and promote angiogenesis in chronic wounds.

Soluble components from mesenchymal stromal cell processing exert anti-inflammatory effects and facilitate ischemic muscle regeneration.

BACKGROUND AIMS: Skeletal muscle regeneration after severe damage is reliant on local stem cell proliferation and differentiation, processes that are tightly regulated by macrophages. Peripheral artery disease is a globally prevalent cardiovascular disease affecting millions of people. Progression of the disease leads to intermittent claudication, subsequent critical limb ischemia and muscle injury. Tissue-derived and ex vivo-expanded mesenchymal stromal cells (MSCs) for skeletal muscle regeneration have been studied, but pre-clinical and clinical results have not been consistent. As a result, the potential therapeutic efficacy and associated repair mechanisms of MSCs remain unclear. Numerous studies have demonstrated the vulnerability of delivered MSCs, with a precipitous drop in cell viability upon transplantation. This has prompted investigation into the therapeutic benefit of apoptotic cells, microvesicles, exosomes and soluble signals that are released upon cell death. METHODS: In this study, we characterized various components produced by MSCs after cell death induction under different conditions. We discovered anti-inflammatory and pro-regenerative effects produced by cell components following a freeze and thaw (F&T) process on macrophage polarization in vitro. We further investigated the underlying mechanisms of macrophage polarization by those components resulting from severe cell death induction. RESULTS: We found potent therapeutic effects from F&T-induced cell debris are dependent on the externalization of phosphatidylserine on the plasma membrane. In contrast, effects from the supernatant of F&T-induced cell death primarily depends on the released protein content. We then applied the F&T-induced cell supernatant to an animal model of peripheral artery disease to treat muscle injury caused by severe ischemia. Treatment with the F&T supernatant but not the vulnerable MSCs resulted in significantly improved recovery of muscle function, blood flow and morphology and inflammation resolution in the affected muscles 2 weeks after injury. CONCLUSIONS: This study validates the therapeutic potential of F&T-induced supernatant obviating the need for a viable population from vulnerable MSCs to treat injury, thus providing a roadmap for cell-free therapeutic approaches for tissue regeneration.

Apoptotic body-inspired nanoparticles target macrophages at sites of inflammation to support an anti-inflammatory phenotype shift.

Chronic inflammation is a significant pathological process found in a range of disease states. Treatments to reduce inflammation in this family of diseases may improve symptoms and disease progression, but are largely limited by variable response rates, cost, and off-target effects. Macrophages are implicated in many inflammatory diseases for their critical role in the maintenance and resolution of inflammation. Macrophages exhibit significant plasticity to direct the inflammatory response by taking on an array of pro- and anti-inflammatory phenotypes based on extracellular cues. In this work, a nanoparticle has been developed to target sites of inflammation and reduce the inflammatory macrophage phenotype by mimicking the anti-inflammatory effect of apoptotic cell engulfment. The nanoparticle, comprised of a poly(lactide-co-glycolide) core, is coated with phosphatidylserine (PS)-supplemented cell plasma membrane to emulate key characteristics of the apoptotic cell surface. The particle surface is additionally functionalized with an acid-sensitive sheddable polyethylene glycol (PEG) moiety to increase the delivery of the nanoparticles to low pH environments such as those of chronic inflammation. In a mouse model of lipopolysaccharide-induced inflammation, particles were preferentially taken up by macrophages at the site and promoted an anti-inflammatory phenotype shift. This PEGylated membrane coating increased the delivery of nanoparticles to sites of inflammation and may be used as a tool alone or as a delivery scheme for additional cargo to reduce macrophage-associated inflammatory response.

HER2 positivity as a biomarker for poor prognosis and unresponsiveness to anti-EGFR therapy in colorectal cancer.

PURPOSE: To investigate the role of HER2 positivity in prognosis and unresponsiveness to anti-EGFR therapy for colorectal cancer. METHODS: Patients who underwent primary CRC tumor resection were included. HER2 status of CRC was confirmed by immunohistochemistry and fluorescence in situ hybridization tests. Comparison of survival analysis between HER2 positivity and negativity was evaluated by a stratified log-rank test and summarized with the use of Kaplan-Meier and Cox proportional hazards methods. The treatment effects of cetuximab were further compared in full subgroup analyses. RESULT: 1240 patients were enrolled, including 763 with stage I-III CRC and 477 with stage IV CRC. 57 (4.6%) CRC patients presented HER2 positivity in the entire cohort. The survival analysis showed that patients with HER2 positivity had significantly worse disease-free survival and overall survival in stage III and IV CRC. The multivariable analysis also confirmed that HER2 positivity was a significantly independent risk factor in stage III and IV CRC. Univariate and multivariable survival analysis showed no prognostic significance of HER2 positivity in stage I-II CRC patients. Prespecified subgroup analysis showed no favorable trends in progression-free survival and overall survival for cetuximab in the patients with HER2 positivity, KRAS/NRAS/BRAF wild-type metastatic CRC (interaction P values = 0.005 and 0.014). CONCLUSION: For stage III and IV CRC patients, HER2 positivity was confirmed as an independent prognostic risk factor. It could help predict the unresponsiveness to anti-EGFR therapy for metastatic CRC.

Cell-Inspired Biomaterials for Modulating Inflammation.

Inflammation is a crucial part of wound healing and pathogen clearance. However, it can also play a role in exacerbating chronic diseases and cancer progression when not regulated properly. A subset of current innate immune engineering research is focused on how molecules such as lipids, proteins, and nucleic acids native to a healthy inflammatory response can be harnessed in the context of biomaterial design to promote healing, decrease disease severity, and prolong survival. The engineered biomaterials in this review inhibit inflammation by releasing anti-inflammatory cytokines, sequestering proinflammatory cytokines, and promoting phenotype switching of macrophages in chronic inflammatory disease models. Conversely, other biomaterials discussed here promote inflammation by mimicking pathogen invasion to inhibit tumor growth in cancer models. The form that these biomaterials take spans a spectrum from nanoparticles to large-scale hydrogels to surface coatings on medical devices. Cell-inspired molecules have been incorporated in a variety of creative ways, including loaded into or onto the surface of biomaterials or used as the biomaterials themselves. Impact statement Chronic inflammatory diseases and cancers are widespread health care concerns. Treatment plans for these diseases can be complicated and the outcomes are often mixed due to off-target effects. Current research efforts in immune engineering and biomaterials are focused on utilizing the body's native immune response to return to homeostasis as a therapeutic approach. This review collects many of the most current findings in the field as a resource for future research.

Short-term and long-term outcomes of robotic rectal surgery-from the real word data of 1145 consecutive cases in China.

BACKGROUND: Due to a limited patient sample size, substantial data on robotic rectal resection (RRR) is lacking. Here, we reported a large consecutive cases from the real word data to assess the safety and efficacy of RRR. METHODS: From September 2010 to June 2017, a total of 1145 consecutive RRR procedures were performed in patients with stage I-IV disease. We conducted an analysis based on information from a prospectively designed database to evaluate surgical outcomes, urogenital function, and long-term oncological outcomes. RESULTS: Of three types of RRR performed, 227 (24.2%) were abdominoperineal resections, 865 (75.5%) were anterior resections, and 3 (0.3%) were Hartmann. Conversion to an open procedure occurred in 5.9% of patients. The overall positive circumferential margin rate was 1.3%. Surgical complication rate and mortality were 16.2% and 0.8% within 30 days of surgery, respectively. Mean hospital stay after surgery and hospital cost were 6.3 ± 2.9 days and 10442.5 ± 3321.5 US dollars, respectively. Risk factors for surgical complications included male gender, tumor location (mid-low rectum), combined organ resection, and clinical T category (cT3-4). Urinary function and general sexual satisfaction decreased significantly 1 month after surgery for both sexes. Subsequently, both parameters increased progressively, and the values 1 year after surgery were comparable to those measured before surgery. At a median follow-up of 34.6 months, local recurrence and distant metastases occurred in 2.3% and 21.1% of patients, respectively. CONCLUSIONS: Robotic rectal resection was safe with preserved urogenital function and arrived equivalent oncological outcomes in a nonselected group of patients with rectal cancer.

Cell-free DNA derived from cancer cells facilitates tumor malignancy through Toll-like receptor 9 signaling-triggered interleukin-8 secretion in colorectal cancer.

Circulating cell-free DNA (cfDNA) has become a potential diagnostic and prognostic biomarker for colorectal cancer (CRC). In non-cancerous diseases, it has been confirmed that cfDNA can be recognized by Toll-like receptor 9 (TLR9), leading to a significant biological change. Nevertheless, the biological significance of cfDNA and its relationship with TLR9 in tumor malignancy is still unclear. Therefore, the purpose of this study is to explore the biological role of cfDNA in colorectal cancer (CRC). The expression of TLR9 was measured in different CRC cell lines and cancerous samples by RT-PCR or immunohistochemistry, which showed that high expression of TLR9 was significantly correlated with the tumor metastasis, advanced TNM stage and poor prognosis of patients. Then, cfDNA was obtained from fluorouracil (5FU)-induced apoptotic cancer cells in vitro and transfection techniques were used to transfect siRNA and cDNA plasmid for TLR9. Cancer cells were stimulated using isolated cfDNA fragments, and results showed that cfDNA could promote colorectal cancer cell proliferation via TLR9. Meanwhile, we demonstrated that the cfDNA binding to TLR9 could facilitate cell migration and invasion. Finally, we demonstrated that cfDNA initiated downstream TLR9-MyD88 signaling and induced robust release of chemokine interleukin 8 (IL-8), which helped to elucidate the mechanisms underlying these phenomena. Our data suggest that cancer cell-derived cfDNA contributes to cancer progression through activation of TLR9-MyD88 signaling and IL-8 secretion in CRC. These findings provide a novel perspective for understanding of tumor progression and provoke a potential therapeutic target for CRC treatment.

Silencing Bag-1 gene via magnetic gold nanoparticle-delivered siRNA plasmid for colorectal cancer therapy in vivo and in vitro.

Apoptosis disorder is generally regarded as an important mechanism of carcinogenesis. Inducement of tumor cell apoptosis can be an effectual way to treat cancer. Bcl-2-associated athanogene 1 (Bag-1) is a positive regulator of Bcl-2 which is an anti-apoptotic gene. Bag-1 is highly expressed in colorectal cancer, which plays a critical role in promoting metastasis, poor prognosis, especially in anti-apoptotic function, and is perhaps a valuable gene target for colorectal cancer therapy. Recently, we applied a novel non-viral gene carrier, magnetic gold nanoparticle, and mediated plasmid pGPH1/GFP/Neo-Bag-1-homo-825 silencing Bag-1 gene for treating colorectal cancer in vivo and in vitro. By mediating with magnetic gold nanoparticle, siRNA plasmid was successfully transfected into cell. In 3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide (MTT) assay, magnetic gold nanoparticle had no significant cytotoxicity and by which delivered RNA plasmid inhibited cell viability significantly (P < 0.05). Downregulation of Bag-1 promoted cell apoptosis (∼47.0 %) in vitro and significantly decreased tumor growth when the cells were injected into nude mice. Based on the studies in vivo, the relative expression of Bag-1 was 0.165 ± 0.072 at mRNA level and ∼60 % at protein level. In further study, C-myc and ß-catenin, mainly molecules of Wnt/ß-catenin pathway, were decreased notably when Bag-1 were silenced in nanoparticle plasmid complex-transfected Balb c/nude tumor xenograft. In conclusion, Bag-1 is confirmed an anti-apoptosis gene that functioned in colorectal cancer, and the mechanism of Bag-1 gene causing colorectal cancer may be related to Wnt/ß-catenin signaling pathway abnormality and suggested that magnetic gold nanoparticle-delivered siRNA plasmid silencing Bag-1 is an effective gene therapy method for colorectal cancer.

Magnetic gold nanoparticle-mediated small interference RNA silencing Bag-1 gene for colon cancer therapy.

Bcl-2-associated athanogene 1 (Bag-1) is a positive regulator of Bcl-2 which is an anti-apoptotic gene. Bag-1 was very slightly expressed in normal tissues, but often highly expressed in many tumor tissues, particularly in colon cancer, which can promote metastasis, poor prognosis and anti-apoptotic function of colon cancer. We prepared and evaluated magnetic gold nanoparticle/Bag-1 siRNA recombinant plasmid complex, a gene therapy system, which can transfect cells efficiently, for both therapeutic effect and safety in vitro mainly by electrophoretic mobility shift assays, flow cytometric analyses, cell viability assays, western blot analyses and RT-PCR (real-time) assays. Magnetic gold nanoparticle/Bag-1 siRNA recombinant plasmid complex was successfully transfected into LoVo colon cancer cells and the exogenous gene was expressed in the cells. Flow cytometric results showed apoptosis rate was significantly increased. In MTT assays, magnetic gold nanoparticles revealed lower cytotoxicity than Lipofectamine 2000 transfection reagents (P<0.05). Both in western blot analyses and RT-PCR assays, magnetic gold nanoparticle/Bag-1 siRNA recombinant plasmid complex transfected cells demonstrated expression of Bag-1 mRNA (P<0.05) and protein (P<0.05) was decreased. In further study, c-myc and ß-catenin which are main molecules of Wnt/ß­catenin pathway were decreased when Bag-1 were silenced in nanoparticle plasmid complex transfected LoVo cells. These results suggest that magnetic gold nanoparticle mediated siRNA silencing Bag-1 is an effective gene therapy method for colon cancer.

The research of nanoparticles as gene vector for tumor gene therapy.

With the development of molecular biology, the application of the gene therapy becomes a tendency in the development of oncotherapy. The gene therapy has been acknowledged as the major progress of modern medicine, also a focus in the oncotherapy research. Commonly vectors of the gene therapy mainly include two categories, namely, viral vectors and nonviral vectors. Nanoparticles gene vector of various different kinds of materials, which belong to non-viral carriers. It presents excellent abilities of adsorption, concentration and protection of DNA, which can be attributed as a main reason of the adsorption and operation of nano-gene vector on exogenous genes. In this article, we mainly reviewed the recent studies of the characteristics of nanoparticles, characteristics and transport mechanism of nanoparticles as gene vector, the progress on nanoparticles as gene vector in tumor gene therapy. Nano-gene vectors, as new drug and gene carriers, present characteristics such as the controlled-release, targeting, and the improvement of bioavailability. Nanoparticles for cancer imaging and therapy have evolved rapidly during the last decade and it is expected that more and more will become clinical practise. In the near future, as a new nanometer gene delivery vector will be in medical research and treatment play a bigger role.