Toward implementing virtual control groups in nonclinical safety studies.

Historical data from control groups in animal toxicity studies are currently mainly used for comparative purposes to assess validity and robustness of study results. Due to the highly controlled environment in which the studies are performed and the homogeneity of the animal collectives it has been proposed to use the historical data to build so-called virtual control groups, which could partly or entirely replace the concurrent control group. This would constitute a substantial contribution to the reduction of animal use in safety studies.

The effect of Nano-liposomal sodium nitrite on smooth muscle cell growth in a tissue-engineered small-diameter vascular graft.

Background: Nitric oxide is a chemical agent produced by endothelial cells in a healthy blood vessel, inhibiting the overgrowth of vascular smooth muscle cells and regulating vessel tone. Liposomes are biocompatible and biodegradable drug carriers with a similar structure to cell bilayer phospholipid membrane that can be used as useful nitric oxide carriers in vascular grafts.

Method: Using a custom-designed apparatus, the sheep carotid arteries were decellularized while still maintaining important components of the vascular extracellular matrix (ECM), allowing them to be used as small-diameter vascular grafts.

A case of recurrent pneumothorax and skin lesions diagnosed with Birt-Hogg-Dubé.

Birt-Hogg-Dubé (BHD) syndrome is an autosomal dominant disease that is manifested as benign cutaneous tumors, multiple lung parenchymal cysts and an increased risk of renal cancer. Its symptoms usually do not appear until adulthood. We report a patient who was admitted with recurrent pneumothorax.

A biomaterials approach to Schwann cell development in neural tissue engineering.

Schwann cells, in addition to forming myelin sheaths, have pivotal roles in regeneration of injured axons in the peripheral nervous system such as producing a natural permissive conduit between distal and proximal stumps and secreting nerve growth factors. Due to the atrophy and senescence of Schwann cells in long nerve gap, and the need to ensure the presence of nerve growth factors and basal lamina tubes for axon regeneration in a critical time, injection of Schwann cells with the aid of an engineered conduit seems to be an effective approach to induce axon regrowth. Stem cells with high differentiation and proliferation capability can provide an adequate number of Schwann cells in healthy state for regeneration purposes.

Biological and nano-indentation properties of polybenzoxazine-based composites reinforced with zirconia particles as a novel biomaterial.

Introduction: The biological and mechanical properties of substances are relevant to their application as biomaterials and there are many efforts to enhance biocompatibility and mechanical properties of bio-medical materials.

Objectives: In this study, to achieve a low rate of shrinkage during polymerization, good mechanical properties, and excellent biocompatibility, benzoxazine based composites were synthesized.

Methods: Benzoxazine monomer was synthesized using a solventless method.