Silver nanoparticle interactions with glycated and non-glycated human serum albumin mediate toxicity.

Introduction: Biomolecules bind to and transform nanoparticles, mediating their fate in biological systems. Despite over a decade of research into the protein corona, the role of protein modifications in mediating their interaction with nanomaterials remains poorly understood. In this study, we evaluated how glycation of the most abundant blood protein, human serum albumin (HSA), influences the formation of the protein corona on 40 nm silver nanoparticles (AgNPs) and the toxicity of AgNPs to the HepG2 human liver cell line. Methods: The effects of glycation on AgNP-HSA interactions were quantified using circular dichroism spectroscopy to monitor protein structural changes, dynamic light scattering to assess AgNP colloidal stability, zeta potential measurements to measure AgNP surface charge, and UV-vis spectroscopy and capillary electrophoresis (CE) to evaluate protein binding affinity and kinetics. The effect of the protein corona and HSA glycation on the toxicity of AgNPs to HepG2 cells was measured using the WST cell viability assay and AgNP dissolution was measured using linear sweep stripping voltammetry. Results and Discussion: Results from UV-vis and CE analyses suggest that glycation of HSA had little impact on the formation of the AgNP protein corona with protein-AgNP association constants of ≈2x107 M-1 for both HSA and glycated HSA (gHSA). The formation of the protein corona itself (regardless of whether it was formed from HSA or glycated HSA) caused an approximate 2-fold decrease in cell viability compared to the no protein AgNP control. While the toxicity of AgNPs to cells is often attributed to dissolved Ag(I), dissolution studies showed that the protein coated AgNPs underwent less dissolution than the no protein control, suggesting that the protein corona facilitated a nanoparticle-specific mechanism of toxicity. Overall, this study highlights the importance of protein coronas in mediating AgNP interactions with HepG2 cells and the need for future work to discern how protein coronas and protein modifications (like glycation) may alter AgNP reactivity to cellular organisms.

MAIT and Vδ2 unconventional T cells are supported by a diverse intestinal microbiome and correlate with favorable patient outcome after allogeneic HCT.

Microbial diversity is associated with improved outcomes in recipients of allogeneic hematopoietic cell transplantation (allo-HCT), but the mechanism underlying this observation is unclear. In a cohort of 174 patients who underwent allo-HCT, we demonstrate that a diverse intestinal microbiome early after allo-HCT is associated with an increased number of innate-like mucosal-associated invariant T (MAIT) cells, which are in turn associated with improved overall survival and less acute graft-versus-host disease (aGVHD). Immune profiling of conventional and unconventional immune cell subsets revealed that the prevalence of Vδ2 cells, the major circulating subpopulation of γδ T cells, closely correlated with the frequency of MAIT cells and was associated with less aGVHD. Analysis of these populations using both single-cell transcriptomics and flow cytometry suggested a shift toward activated phenotypes and a gain of cytotoxic and effector functions after transplantation. A diverse intestinal microbiome with the capacity to produce activating ligands for MAIT and Vδ2 cells appeared to be necessary for the maintenance of these populations after allo-HCT. These data suggest an immunological link between intestinal microbial diversity, microbe-derived ligands, and maintenance of unconventional T cells.

Arthroscopic Single Portal, Single Anchor Knotless Subscapularis Repair with Concomitant Tenodesis of the Long Head of the Biceps Tendon.

Anterior shoulder pathology involving the subscapularis is often associated with the biceps tendon because both anatomic structures intersect the lesser tuberosity. Standard procedures for such pathology often involve simultaneous subscapularis repairs and biceps tenodesis. Single anterior portal subscapularis repairs have been emerging in the past 5 years because of cost-effectiveness and efficiency. Biceps tenodesis is a common procedure performed both open and arthroscopically. This technique takes advantage of the close relation between the long head of the biceps tendon and subscapularis tendon to restore the functional length-tension relation and preserve function through fixation using a single portal and a single knotless suture anchor.

Four-Strand Hamstring Diamond Braid Technique for Anterior Cruciate Ligament Reconstruction.

Several factors affect the success of an anterior cruciate ligament reconstruction, including graft origin, type, and morphology. Hamstring and bone-patellar tendon-bone autografts are the most widely used, and there are many different techniques of graft preparation with each. In this Technical Note and accompanying video, a 4-strand hamstring autograft technique is described that uses a simple diamond-type braid to produce a more ovoid morphology with increased cross-sectional area. Increased graft diameters have been associated with higher success rates and more positive long-term outcomes. Therefore, this braiding construct may provide additional tensile strength with increased resistance to failure than grafts that are otherwise undersized using conventional techniques.

Combined Coracoclavicular and Acromioclavicular Joint Reconstruction with Allograft Using a Cerclage Tensioning System.

Acromioclavicular joint separations are common shoulder injuries, yet standard treatment practices vary. Popular surgical techniques include reconstruction using allografts or neighboring ligaments as well as repair using screws and sutures. This Technical Note and accompanying video describe both an acromioclavicular and coracoclavicular joint reconstruction using an allograft to replace native acromioclavicular ligament along with an AC joint reduction using a Suture Cerclage System to precisely control reduction and restore anatomic alignment.

Distal Clavicle Excision for Acromioclavicular Joint Osteoarthritis Using a Fluoroscopic Kirschner Wire Guide.

Pathology of the acromioclavicular joint is common and often resistant to conservative treatment, requiring distal clavicle excision for definitive relief. First described as an open technique by Mumford and Gurd in 1941, distal clavicle excision has evolved greatly, with arthroscopic techniques currently predominating. No significant difference has been found in patient satisfaction or rate of complication between the techniques in a recent meta-analysis. Indeed, open excisions are still performed at a high rate, owing to the difficulty in technique and visualization with arthroscopic methods. One major critique of arthroscopic distal clavicle excision is difficulty safeguarding against under- and overexcision of the distal clavicle due to the lack of depth perception and visual reference points of the arthroscopic perspective. This Technical Note and accompanying video describe an indirect subacromial arthroscopic distal clavicle excision using a fluoroscopic Kirschner wire guide placed at the proximal border prior to resection to serve as a visual and mechanical reference to overexcision.

Mini-Open Achilles Repair With a Flat Braided Suture in a Low-Profile Configuration.

Achilles repair has evolved over the past 30 years, from large open procedures with high complication rates to shorter, less-invasive procedures with better outcomes. Percutaneous repair has comparable failure rates with open repairs, fewer complications, and faster recovery. However, percutaneous Achilles repairs risk sural nerve injury. A mini-open repair fuses the gap between percutaneous and open procedures, and this approach has the potential to mitigate nerve injury while maintaining the increased efficiency in procedure time and patient recovery. The purpose of this Technical Note and accompanying video is to outline the repair of the Achilles tendon using a mini open repair using a low-profile flat braided suture.