Biomaterials
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Randomized Controlled Trial
Intramedullary nailing of forearm shaft fractures by biodegradable compared with titanium nails: Results of a prospective randomized trial in children with at least two years of follow-up.
There are disadvantages in Elastic Stable Intramedullary Nailing (ESIN) of forearm-shaft fractures, such as the need of implant removal. Biodegradable Intramedullary Nailing (BIN) is a new technique developed for these fractures. We hypothesized that there is no difference in rotational ROM between the patients treated by BIN vs. ⋯ There was no clinically significant residual angulation in radiographs. Two adolescents in the BIN group vs. none in the ESIN (P = 0.245) were excluded because of implant failure; another two with complete bone union suffered from re-injury. Therefore, satisfactory implant stability among older children needs to be studied.
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Metronomic chemotherapy, which is defined as a low-dose and frequent administration of cytotoxic drugs without drug-free breaks, has been recently emerged as an alternative to traditional MTD therapy and has shown therapeutic benefit in breast cancer patients in numbers of clinical studies. Unlike MTD, metronomic chemotherapy acts by multiple mechanisms including antiangiogenic effect and immunomodulation, but the direct cytotoxic effect only playing a minor role due to the lowered dose. In this light, within the limits of p53-deficient breast cancer, we demonstrate the enhanced anticancer effect of metronomic chemotherapy using doxorubicin when combined with Chk1 inhibitor MK-8776 by specifically augmenting the direct cytotoxic effect on cancer cells. ⋯ MK-8776 selectively enhanced the cytotoxic effect of low-concentration doxorubicin in p53-deficient breast cancer cells by abrogating the Chk1-dependent cell cycle arrest in vitro. Consistently, combining MK-8776 significantly improved the anticancer effect of the daily administered oral doxorubicin in p53-deficient breast cancer xenografts especially in a lower dose of doxorubicin without evident systemic toxicities. Combination therapy of MK-8776 and metronomic oral doxorubicin would be thus promising in the treatment of p53-deficient breast cancer benefited from the augmented direct cytotoxic effect and low risk of toxicities.
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Current ISC culture systems face significant challenges such as animal-derived or undefined matrix compositions, batch-to-batch variability (e.g. Matrigel-based organoid culture), and complexity of assaying cell aggregates such as organoids which renders the research and clinical translation of ISCs challenging. Here, through screening for suitable ECM components, we report a defined, collagen based monolayer culture system that supports the growth of mouse and human intestinal epithelial cells (IECs) enriched for an Lgr5+ population comparable or higher to the levels found in a standard Matrigel-based organoid culture. ⋯ Further, we apply our BLT Sandwich system to identify that the addition of a bone morphogenetic protein (BMP) receptor inhibitor (LDN-193189) improves the expansion of Lgr5-GFP+ cells from mouse small intestinal crypts by nearly 2.5-fold. Notably, the BLT Sandwich culture is capable of expanding human-derived IECs with higher LGR5 mRNA levels than conventional Matrigel culture, providing superior expansion of human LGR5+ ISCs. Considering the key roles Lgr5+ ISCs play in intestinal epithelial homeostasis and regeneration, we envision that our BLT Sandwich culture system holds great potential for understanding and manipulating ISC biology in vitro (e.g. for modeling ISC-mediated gut diseases) or for expanding a large number of ISCs for clinical utility (e.g. for stem cell therapy).
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The SDF-1α chemokine (CXCL12) is a potent bioactive chemoattractant known to be involved in hematopoietic stem cell homing and cancer progression. The associated SDF-1α/CXCR4 receptor signaling is a hallmark of aggressive tumors, which can metastasize to distant sites such as lymph nodes, lung and bone. Here, we engineered a biomimetic tumoral niche made of a thin and soft polyelectrolyte film that can retain SDF-1α to present it, in a spatially-controlled manner, at the ventral side of the breast cancer cells. ⋯ The CXCR4/CD44 mediated cellular response to matrix-bound SDF-1α involved the Rac1 RhoGTPase and was sustained solely in the presence of matrix-bound SDFα, in contrast with the transient signaling observed in response to soluble SDF-1α. Our results highlight that a biomimetic tumoral niche enables to reveal potent cellular effects and so far hidden molecular mechanisms underlying the breast cancer response to chemokines. These results open new insights for the design of future innovative therapies in metastatic cancers, by inhibiting CXCR4-mediated signaling in the tumoral niche via dual targeting of receptors (CXCR4 and CD44) or of associated signaling molecules (CXCR4 and Rac1).
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Implant related infection is one of the most feared and devastating complication associated with the use of orthopaedic implant devices. Development of anti-infective surfaces is the main strategy to prevent implant contamination, biofilm formation and implant related osteomyelitis. A second concern in orthopaedics is insufficient osseointegration of uncemented implant devices. ⋯ The interobserver reliability showed no difference in the histologic and radiographic osteomyelitis scores. In both gentamicin coated groups, a significant reduction of the histological osteomyelitis score (geometric mean values: C = 0.111 ± 0.023; D = 0.056 ± 0.006) compared to the positive control group (B: 0.244 ± 0.015; p < 0.05) was observed. The radiographic osteomyelitis scores confirmed these histological findings.