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The Anterior Cruciate Ligament (ACL) is the most commonly injured knee ligament with more than 250.000 ACLs injured patients yearly. Based on the problems encountered in the manufacture of ligament tissue engineering, the researchers focused on strategies to improve their mechanical properties. Nanofibers can be made into various shapes and sizes to improve their mechanical properties, one of which is using the braiding method. In this study, we synthesized an electrospun nanofiber scaffold based on polylactic acid – polycaprolactone (PLA-PCL) which are variations of braided 3, 4, and 6 with braid angles of 60° and 80°. The purpose of the study was to determine the effect of the braid structure on the tensile test and degradation test. The best results of Ultimate Tensile Strength (UTS) and Young's modulus were on the 6 braid samples and the 60° angle variation. The braiding method with a smaller angle and a higher number of braided bundles can increase the UTS value because the structures are more closely related so they will bind to each other when a tensile force is applied. Meanwhile, the longest degraded sample for the degradation test was 4 braids and a 60° angle for 15 weeks. PLA-PCL material has met the mechanical strength requirements to become an artificial ligament, but mechanical quality improvement can be done by increasing the variation of the braiding angle and the amount of braiding on the structure. [ABSTRACT FROM AUTHOR]

Recently, it was found that the case of knee injuries could reach a prevalence of 48 per 1000 peoples in one year, with 9% being categorized as Anterior Cruciate Ligament (ACL) injuries. The most common cause of ACL injuries is sports activities. Several strategies were used to heal this injury, such as a treatment, up to autographs bone graft surgery. Current research developments lead to the use of artificial ligaments to heal the ACL injuries which have many advantages over autografts. Thus, this present study aims to fabricate the artificial ligament using hydroxyapatite (HA)/collagen/polycaprolactone (PCL) nanofiber composites. Here, we try to determine the effect of variations of HA, collagen, and PCL compositions in the nanofiber composites by studying their crystal structure and mechanical properties (tensile strength). We use variations of PCL: HA: collagen compositions about of 50:45:5, 50:40:10, 50:35:15, 50:30:20, and 50:25:25 wt%, respectively, in the 10% w/v of solution concentrations. In this present research, the nanofiber was fabricated by using electrospinning method with a voltage of 23 kV, while, the distance between the needle and the collector of about of 15 cm. The XRD and tensile strength tests were used to study the effects of PCL: HA: collagen compositions. In the XRD test, we found that the PCL peaks were detected at 2θ = 21° and 23° and HA was found at 2θ = 31°. The PCL crystal size is found to be 47.82-86.87 nm and the degree of crystallinity is 24.31-36.87%. In the mechanical test, the Ultimate Tensile Strength (UTS) value was obtained in the range of 0.942 MPa-2.864 MPa. It was found that the PCL could increase the tensile strength. However, the obtained UTS value is still far from the UTS of the original human ACL value. [ABSTRACT FROM AUTHOR]

Multiferroic nanocomposite thin film containing single phase multiferroic BiFeO3 (BFO) and ferrimagnetic CoFe2O4 (CFO) have successfully fabricated utilizing two distinct thin film architectures. Namely, the multilayer and vertically aligned nanocomposite architectures, which is, have a different role to the magnetic coupling mechanism. A magnetic saturation enhancement occurs in the BFO-CFO vertically aligned nanocomposite due to a strong magnetic coupling between pillars and matrix manifested in vertically aligned nanocomposite architecture. [ABSTRACT FROM AUTHOR]

Multiferroic nanocomposite is recognized as one class of multiferroic with high magnetoelectric coefficient offered by their excellent magnetic-electric coupling via strain interaction. The strain interaction or structural coupling in this system is very important, which is, it can be tuned further by modifying the nanocomposite architectures. Here, we conduct a comparative study of the multiferroic nanocomposite BiFeO3 (BFO)-CoFe2O4 (CFO)/SrTiO3 (STO) with various vertically aligned nanocomposite architectures. It appears that both of BFO and CFO phases can be formed as a matrix and/or a pillars or vice versa depending on the crystalline orientation of STO substrate. The formation of matrix- pillars are strongly influenced by surface energy anisotropy between constituent BFO and CFO phases. [ABSTRACT FROM AUTHOR]