Functional biomaterials for tendon/ligament repair and regeneration

With an increase in life expectancy and the popularity of highintensity exercise,the frequency of tendon and ligament injuries has also increased.Owing to the specificity of its tissue,the rapid restoration of injured tendons and ligaments is challenging for treatment.This review summarizes the latest progress in cells,biomaterials,active molecules and construction technology in treating tendon/ligament injuries.The characteristics of supports made of different materials and the development and application of different manufacturing methods are discussed.The development of natural polymers,synthetic polymers and composite materials has boosted the use of scaffolds.In addition,the development of electrospinning and hydrogel technology has diversified the production and treatment of materials.First,this article briefly introduces the structure,function and biological characteristics of tendons/ligaments.Then,it summarizes the advantages and disadvantages of different materials,such as natural polymer scaffolds,synthetic polymer scaffolds,composite scaffolds and extracellular matrix(ECM)-derived biological scaffolds,in the application of tendon/ligament regeneration.We then discuss the latest applications of electrospun fiber scaffolds and hydrogels in regeneration engineering.Finally,we discuss the current problems and future directions in the development of biomaterials for restoring damaged tendons and ligaments.

Mechanical Analysis of a No-insulation Pancake Coil with the Overband During a Quench

The no-insulation(NI)winding approach can remarkably improve the thermal stability of high-temperature superconducting coil.However,mechanical issues have gradually become a key factor to block the development of NI magnets in recent years.This paper mainly analyzes the effect of the overband on the mechanical behaviors of an NI coil during a quench.A numerical model including a quench model combined with a three-dimensional homogeneous mechanical model is employed to study the change of stress in the coil without and with the over band during a local quench.The results show that the overband has an obvious effect on the stress distribution as the heater is located at the outer turn of the coil.Meanwhile,the values of stress in the coil are also affected by the overband.Moreover,the effects of the thickness of the overband and the location of the heater on the mechanical behaviors of the coil are also discussed.It is worth noting that the overband can remarkably reduce the hoop and axial tensile stresses of the coil during a quench。