Magnetized chitosan hydrogel and silk fibroin, reinforced with PVA: a novel nanobiocomposite for biomedical and hyperthermia applications.

Herein, a multifunctional nanobiocomposite was designed for biological application, amongst which hyperthermia cancer therapy application was specifically investigated. This nanobiocomposite was fabricated based on chitosan hydrogel (CS), silk fibroin (SF), water-soluble polymer polyvinyl alcohol (PVA) and iron oxide magnetic nanoparticles (Fe3O4 MNPs). CS and SF as natural compounds were used to improve the biocompatibility, biodegradability, adhesion and cell growth properties of the nanobiocomposite that can prepare this nanocomposite for the other biological applications such as wound healing and tissue engineering. Since the mechanical properties are very important in biological applications, PVA polymer was used to increase the mechanical properties of the prepared nanobiocomposite. All components of this nanobiocomposite have good dispersion in water due to the presence of hydrophilic groups such as NH2, OH, and COOH, which is one of the effective factors in increasing the efficiency of hyperthermia cancer therapy. The structural analyzes of the hybrid nanobiocomposite were determined by FT-IR, XRD, EDX, FE-SEM, TGA and VSM. Biological studies such as MTT and hemolysis testing proved that it is hemocompatible and non-toxic for healthy cells. Furthermore, it can cause the death of cancer cells to some extent (20.23%). The ability of the nanobiocomposites in hyperthermia cancer therapy was evaluated. Also, the results showed that it can be introduced as an excellent candidate for hyperthermia cancer therapy.

Magnetic chitosan-silk fibroin hydrogel/graphene oxide nanobiocomposite for biological and hyperthermia applications.

This work represents a biocompatible magnetic nanobiocomposite prepared by the composition of chitosan (CS) hydrogel, silk fibroin (SF), graphene oxide (GO), and Fe3O4 NPs. Terephthaloyl thiourea was applied as a cross-linking agent to cross-link the CS strings. The CS hydrogel/SF/GO/Fe3O4 nanobiocomposite with many characteristics, such as high structural uniformity, thermal stability, biocompatibility, and stability in an aqueous solution. Various characteristics of this novel magnetic nanobiocomposite were distinguished by FT-IR, EDX, FE-SEM, XRD, TGA, and VSM analysis. The FE-SEM images were taken to evaluate the size distribution of the magnetic nanoparticles (MNPs) between 39.9 and 73.3 nm as well. The performance of the prepared nanobiocomposite was assessed by the magnetic fluid hyperthermia process. Under the alternating magnetic field (AMF), the mean value of the specific absorption rate (SAR) was determined at 43.15 w/g.

The Effects of Chronic Ankle Instability on the Biomechanics of the Uninjured, Contralateral Ankle During Gait.

OBJECTIVE: To determine whether unilateral chronic ankle instability (CAI) affects the kinematics of the uninjured contralateral ankle. METHODS: In this case-control study, 15 adult patients with unilateral CAI and 15 healthy controls were studied. Both the unstable and uninjured ankles in patients with unilateral CAI (CAI group, n = 15) were compared with that of healthy individuals (control group, n = 15). Applying body photo-reflective markers, the participant's motion during gait was measured. Biomechanical variables including overall ankle-toe angle, linear velocity, linear acceleration, angular velocity, angular acceleration, range of motion (RoM) in dorsiplantar flexion, and inversion-eversion at initial contact, loading response, mid-stance, terminal stance, pre-swing, and swing phase of the gait were measured. RESULTS: In patients with CAI, the injured and uninjured ankles were significantly different regarding angle-toe angle, inversion-eversion RoM, dorsiplantar flexion in mid-stance, inversion-eversion at initial contact and terminal stance as well as the pre-swing and swing phases (p < 0.01). The uninjured ankles of patients showed lower ankle-toe velocity (p = 0.01) and acceleration (p = 0.01) compared to both the left and right ankles of the controls. In addition, the uninjured ankles of the patients showed decreased ankle dorsiflexion and increased inversion during initial contact, loading response, mid-stance, terminal stance, pre-swing, and swing compared to the control group (p < 0.017). CONCLUSION: The results suggest that unilateral CAI can affect gait biomechanics in the contralateral uninjured ankle. Left unaddressed, unilateral CAI may lead to increased morbidity to the contralateral uninjured side. When surgery is not preferred for the management of unilateral CAI, rehabilitation protocols should focus on both sides.

Biomechanics Following Anatomic Lateral Ligament Repair of Chronic Ankle Instability: A Systematic Review.

One of the most common orthopedic injuries in the general population, particularly among athletes, is ankle sprain. We investigated the literature to evaluate the known pre- and postoperative biomechanical changes of the ankle after anatomic lateral ligament repair in patients suffering from chronic ankle instability. In this systematic review, studies published till January 2020 were identified by using synonyms for "kinetic outcomes," "kinematic outcomes," "Broström procedure," and "lateral ligament repair." Included studies reported on pre- and postoperative kinematic and/or kinetic data. Twelve articles, including 496 patients treated with anatomic lateral ligament repair, were selected for critical appraisal. Following surgery, both preoperative talar tilt and anterior talar translation were reduced similarly to the values found in the uninjured contralateral side. However, 16 of 152 (10.5%) patients showed a decrease in ankle range of motion after the surgery. Despite the use of these various techniques, there were no identifiable differences in biomechanical postoperative outcomes. Anatomic lateral ligament repair for chronic ankle instability can restore ankle biomechanics similar to that of healthy uninjured individuals. There is currently no biomechanical evidence to support or refute a biomechanical advantage of any of the currently used surgical ligament repair techniques mentioned among included studies.

Anterolateral Meniscofemoral Ligament Associated with Ring-shaped Lateral Meniscus and Congenital Absence of Anterior Cruciate Ligament, Managed with Ligament Reconstruction.

A 24 year old otherwise healthy male presented with a chief complaint of giving way in the left knee. MRI reported complete anterior cruciate ligament (ACL) tearing. Arthroscopy showed ACL agenesis, ring-shaped lateral meniscus, and an anomalous thick band extending from the anterior horn of the lateral meniscus to the intercondylar notch of the lateral femoral condyle, which is known as the anterolateral meniscofemoral ligament (MFL). The MFL was attached to the anatomic site of anteromedial bundle of ACL. ACL reconstruction surgery was performed using central 1/3 bone tendon bone graft. Practitioners should be aware that ACL reconstruction in lateral meniscofemoral ligament with associated ACL agenesis is a treatment option in which the preservation of MFL, as the stabilizer of anterior horn of lateral meniscus, should be considered during ACL reconstruction.