Modeling Extracellular Matrix-Cell Interactions in Lung Repair and Chronic Disease

The lung extracellular matrix (ECM) is a complex and dynamic mixture of fibrous proteins (collagen, elastin), glycoproteins (fibronectin, laminin), glycosaminoglycans (heparin, hyaluronic acid) and proteoglycans (perlecan, versican), that are essential for normal lung development and organ health [...]

Histological analysis of elastic cartilages treated with alkaline solution

ABSTRACT The elastic cartilage is composed by chondroblasts and chondrocytes, extracellular matrix and surrounded by perichondrium. It has a low regeneration capacity and is a challenge in surgical repair. One of obstacles in engineering a structurally sound and long-lasting tissue is selecting the most appropriate scaffold material. One of the techniques for obtaining biomaterials from animal tissues is the decellularization that decreases antigenicity. In this work, alkaline solution was used in bovine ear elastic cartilages to evaluate the decellularization and the architecture of the extracellular matrix. The cartilages were treated in alkaline solution (pH13) for 72 hours and lyophilized to be compared with untreated cartilages by histological analysis (hematoxylin-eosin, Masson's trichrome and Verhoeff slides). Areas of interest for cell counting and elastic fiber quantification were delineated, and the distribution of collagen and elastic fibers and the presence of non-fibrous proteins were observed. The results demonstrated that the alkaline solution caused 90% decellularization in the middle and 13% in the peripheral region, and maintenance of the histological characteristics of the collagen and elastic fibers and non-fibrous protein removal. It was concluded that the alkaline solution was efficient in the decellularization and removal of non-fibrous proteins from the elastic cartilages of the bovine ear.

Robert Donald Bruce Fraser 1924–2019

Robert Donald Bruce (Bruce) Fraser was a biophysicist who gained world-wide distinction for his extensive structural studies of fibrous proteins. Bruce began a part-time BSc degree at Birkbeck College, London, while working as a laboratory assistant. In 1942, aged 18, he interrupted his studies and volunteered for training as a pilot in the Royal Air Force (RAF). He was sent to the Union of South Africa and was selected for instructor training, specialising in teaching pilot navigation. At the end of the war he completed his BSc at King’s College, London, and followed this with a PhD. Bruce studied the structure of biological molecules, including DNA, using infra-red micro-spectroscopy in the Biophysics Unit at King’s led by physicist J. T. Randall FRS. During that time Bruce built a structure for DNA that was close to the Watson-Crick structure that gained them and Maurice Wilkins at Kings College, the Nobel Prize in 1962. In 1952, he immigrated to Australia with his family to a position in the newly formed Wool Textile Research Laboratories at the Commonwealth Scientific and Industrial Research Organisation (CSIRO). Here, Bruce established a biophysics group for research on the structure of wool and other fibrous proteins that flourished until his retirement. Over that period he was internationally recognized as the pre-eminent fibrous protein structuralist world-wide. Having been acting chief, Bruce was subsequently appointed chief of the Division of Protein Chemistry and he remained in that role until he took retirement in 1987.

Thermal Conductivity of Protein-Based Materials: A Review

Fibrous proteins such as silks have been used as textile and biomedical materials for decades due to their natural abundance, high flexibility, biocompatibility, and excellent mechanical properties. In addition, they also can avoid many problems related to traditional materials such as toxic chemical residues or brittleness. With the fast development of cutting-edge flexible materials and bioelectronics processing technologies, the market for biocompatible materials with extremely high or low thermal conductivity is growing rapidly. The thermal conductivity of protein films, which is usually on the order of 0.1 W/m·K, can be rather tunable as the value for stretched protein fibers can be substantially larger, outperforming that of many synthetic polymer materials. These findings indicate that the thermal conductivity and the heat transfer direction of protein-based materials can be finely controlled by manipulating their nano-scale structures. This review will focus on the structure of different fibrous proteins, such as silks, collagen and keratin, summarizing factors that can influence the thermal conductivity of protein-based materials and the different experimental methods used to measure their heat transfer properties.