Adipose stem cell coating of biomimetic β-TCP macrospheres by use of laboratory centrifuge

Biomimetic materials such as coral exoskeletons possess unique architectural structures with a uniform and interconnected porous network that can be beneficial as a scaffold material. In addition, these marine structures can be hydrothermally converted to calcium phosphates, while retaining the original structural properties. The ability of biomaterials to stimulate the local microenvironment is one of the main focuses in tissue engineering, and directly coating the scaffold with stem cells facilitates future potential applications in therapeutics and regenerative medicine. In this article we describe a new and simple method that uses a laboratory centrifuge to coat hydrothermally derived beta-tricalcium phosphate macrospheres from coral exoskeleton with stem cells. In this research the optimal seeding duration and speed were determined to be 1 min and 700 g. Scanning electron micrographs showed complete surface coverage by stem cells within 7 days of seeding. This study constitutes an important step toward achieving functional tissue-engineered implants by increasing our understanding of the influence of dynamic parameters on the efficiency and distribution of stem cell attachment to biomimetic materials and how stem cells interact with biomimetic materials. © Copyright 2013, Mary Ann Liebert, Inc. 2013

Gold nanoparticles improve metabolic profile of mice fed a high-fat diet

© 2018 The Author(s). Background: Obesity is a high risk for multiple metabolic disorders due to excessive influx of energy, glucose and lipid, often from a western based diet. Low-grade inflammation plays a key role in the progression of such metabolic disorders. The anti-inflammatory property of gold compounds has been used in treating rheumatoid arthritis in the clinic. Previously we found that pure gold nanoparticles (AuNPs, 21 nm) also possess anti-inflammatory effects on the retroperitoneal fat tissue following intraperitoneal injection, by downregulating tumor necrosis factor (TNF) α. However, whether such an effect can change the risk of metabolic disorders in the obese has not been well studied. The study employed C57BL/6 mice fed a pellet high fat diet (HFD, 43% as fat) that were treated daily with AuNPs [low (HFD-LAu) or high (HFD-HAu) dose] via intraperitoneal injection for 9 weeks. In the in vitro study, RAW264.7 macrophages and 3T3-L1 adipocytes were cultured with low and high concentrations of AuNPs alone or together. Results: The HFD-fed mice showed a significant increase in fat mass, glucose intolerance, dyslipidemia, and liver steatosis. The HFD-LAu group showed an 8% reduction in body weight, ameliorated hyperlipidemia, and normal glucose tolerance; while the HFD-HAu group had a 5% reduction in body weight with significant improvement in their glucose intolerance and hyperlipidemia. The underlying mechanism may be attributed to a reduction in adipose and hepatic local proinflammatory cytokine production, e.g. TNFα. In vitro studies of co-cultured murine RAW264.7 macrophage and 3T3-L1 adipocytes supported this proposed mechanism. Conclusion: AuNPs demonstrate a promising profile for potential management of obesity related glucose and lipid disorders and are useful as a research tool for the study of biological mechanisms

Tensile Properties of the Murine Ventral Vertical Midline Incision

In clinical surgery, the vertical midline abdominal incision is popular but associated with healing failures. A murine model of the ventral vertical midline incision was developed in order to study the healing of this incision type.The strength of the wild type murine ventral abdominal wall in the midline was contained within the dermis; the linea alba made a negligible contribution. Unwounded abdominal wall had a downward trend (nonsignificant) in maximal tension between 12 and 29 weeks of age. The incision attained 50% of its final strength by postoperative day 40. The maximal tension of the ventral vertical midline incision was nearly that of unwounded abdominal wall by postwounding day 60; there was no difference in unwounded vs. wounded maximal tension at postwounding day 120.After 120 days of healing, the ventral vertical midline incision in the wild type mouse was not significantly different from age-matched nonwounded controls. About half of the final incisional strength was attained after 6 weeks of healing. The significance of this work was to establish the kinetics of wild type incisional healing in a model for which numerous genotypes and genetic tools would be available for subsequent study

Engineering thick tissues - the vascularisation problem

The ability to create thick tissues is a major tissue engineering challenge, requiring the development of a suitable vascular supply. Current trends are seeing the utilization of cells seeded into hybrid matrix/scaffold systems to create in vitro vascular analogues. Approaches that aim to create vasculature in vitro include the use of biological extracellular matrices such as collagen hydrogels, porous biodegradable polymeric scaffolds with macro- and micro-lumens and micro-channels, co-culture of cells, incorporation of growth factors, culture in dynamic bioreactor environments, and combinations of these. Of particular interest are those approaches that aim to create bioengineered tissues in vitro that can be readily connected to the host's vasculature following implantation in order to maintain cell viability