Electrospun polycaprolactone incorporated with fluorapatite nanoparticles composite scaffolds enhance healing of experimental calvarial defect on rats.

Background: Composite scaffolds that maximize the advantages of different polymers are widely utilized in guided tissue regeneration (GTR). Some studies found that novel composite scaffolds composed of electrospun polycaprolactone/fluorapatite (ePCL/FA) actively promoted the osteogenic mineralization of various cell types in vitro. However, only a few studies have addressed the application of this composite scaffold membrane material in vivo. In this study, the ability of ePCL/FA composite scaffolds in vivo and their possible mechanisms were preliminarily explored. Methods: In this study, ePCL/FA composite scaffolds were characterized and their effects on bone tissue engineering and repair of calvarial defects in rats were examined. Sixteen male Sprague-Dawley (SD) rats were randomly categorized into four groups: normal group (integral cranial structure without defect), control group (cranial defect), ePCL group (cranial defect repaired by electrospun polycaprolactone scaffolds), and ePCL/FA group (cranial defect repaired by fluorapatite-modified electrospun polycaprolactone scaffolds). At 1 week, 2 months, and 4 months, micro-computed tomography (micro-CT) analysis was performed to compare the bone mineral density (BMD), bone volume (BV), tissue volume (TV), and bone volume percentage (BV/TV). The effects of bone tissue engineering and repair were observed by histological examination (hematoxylin and eosin, Van Gieson, and Masson respectively) at 4 months. Results: In water contact angle measurement, the average contact angle for the ePCL/FA group was significantly lower than that for the ePCL group, indicating that the FA crystal improved the hydrophilicity of the copolymer. Micro-CT analysis revealed that the cranial defect had no significant change at 1 week; however, the BMD, BV, and BV/TV of the ePCL/FA group were significantly higher than those of the control group at 2 and 4 months. Histological examination showed that the cranial defects were almost completely repaired by the ePCL/FA composite scaffolds at 4 months compared to the control and ePCL groups. Conclusions: The introduction of a biocompatible FA crystal improved the physical and biological properties of the ePCL/FA composite scaffolds; thus, these scaffolds demonstrate outstanding osteogenic potential for bone and orthopedic regenerative applications.

Microengineered Flexural Post Rings for Effective Blood Sample Fencing and High-Throughput Measurement of Clot Retraction Force.

During blood clotting, clot retraction alters its mechanical properties and critically affects hemostasis. Despite that, existing clot retraction assays hold limitations such as large footprint and low throughput. In this work, we report the design of flexural post rings for a miniaturized assay of clot retraction force (CRF) with high throughput. Leveraging surface tensions, the post rings hold blood samples in a highly reproducible fashion while simultaneously serving as cantilever beams to measure the CRF. We investigated the effect on the device performance of major parameters, namely, surface hydrophobicity, post number, and post stiffness. We then tested the devices using 14 patient samples and revealed the correlation between CRF and fibrinogen levels. We further implemented an automated liquid handler and developed a high-throughput platform for clot retraction assay. The device's small sample consumption, simple operation, and good compatibility with existing automation facilities make it a promising high-throughput clot retraction assay.

Intraoral management of iatrogenically displaced lower third molar roots in the sublingual space: a report of 2 cases.

Surgical removal of the mandibular third molars is one of the most common procedures performed by dentists, as well as by oral and maxillofacial surgeons. Accidental displacement of teeth or roots into the fascial spaces, during surgical removal of the mandibular third molars, is a rare, but serious complication. Herein, we present 2 cases of iatrogenically displaced mandibular third molar roots into the sublingual space, which were successfully removed under local anesthesia intraorally. In addition to methods to minimize the risk of accidental tooth or root displacement, the importance of recognizing this complication and the methods of retrieval are also discussed.